release: 0.4.0

Signed-off-by: Ophestra <cat@gensokyo.uk>

.gitea/workflows/test.yml

@@ -22,6 +22,57 @@ jobs:
           path: result/*
           retention-days: 1
 
+  race:
+    name: Fortify (race detector)
+    runs-on: nix
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Run NixOS test
+        run: nix build --out-link "result" --print-out-paths --print-build-logs .#checks.x86_64-linux.race
+
+      - name: Upload test output
+        uses: actions/upload-artifact@v3
+        with:
+          name: "fortify-race-vm-output"
+          path: result/*
+          retention-days: 1
+
+  sandbox:
+    name: Sandbox
+    runs-on: nix
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Run NixOS test
+        run: nix build --out-link "result" --print-out-paths --print-build-logs .#checks.x86_64-linux.sandbox
+
+      - name: Upload test output
+        uses: actions/upload-artifact@v3
+        with:
+          name: "sandbox-vm-output"
+          path: result/*
+          retention-days: 1
+
+  sandbox-race:
+    name: Sandbox (race detector)
+    runs-on: nix
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Run NixOS test
+        run: nix build --out-link "result" --print-out-paths --print-build-logs .#checks.x86_64-linux.sandbox-race
+
+      - name: Upload test output
+        uses: actions/upload-artifact@v3
+        with:
+          name: "sandbox-race-vm-output"
+          path: result/*
+          retention-days: 1
+
   fpkg:
     name: Fpkg
     runs-on: nix
@@ -39,29 +90,14 @@ jobs:
           path: result/*
           retention-days: 1
 
-  race:
-    name: Data race detector
-    runs-on: nix
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-
-      - name: Run NixOS test
-        run: nix build --out-link "result" --print-out-paths --print-build-logs .#checks.x86_64-linux.race
-
-      - name: Upload test output
-        uses: actions/upload-artifact@v3
-        with:
-          name: "fortify-race-vm-output"
-          path: result/*
-          retention-days: 1
-
   check:
     name: Flake checks
     needs:
       - fortify
-      - fpkg
       - race
+      - sandbox
+      - sandbox-race
+      - fpkg
     runs-on: nix
     steps:
       - name: Checkout

cmd/fpkg/app.go

@@ -19,7 +19,7 @@ type appInfo struct {
 	// passed through to [fst.Config]
 	ID string `json:"id"`
 	// passed through to [fst.Config]
-	AppID int `json:"app_id"`
+	Identity int `json:"identity"`
 	// passed through to [fst.Config]
 	Groups []string `json:"groups,omitempty"`
 	// passed through to [fst.Config]
@@ -29,7 +29,7 @@ type appInfo struct {
 	// passed through to [fst.Config]
 	Net bool `json:"net,omitempty"`
 	// passed through to [fst.Config]
-	Dev bool `json:"dev,omitempty"`
+	Device bool `json:"dev,omitempty"`
 	// passed through to [fst.Config]
 	Tty bool `json:"tty,omitempty"`
 	// passed through to [fst.Config]
@@ -64,56 +64,61 @@ type appInfo struct {
 
 func (app *appInfo) toFst(pathSet *appPathSet, argv []string, flagDropShell bool) *fst.Config {
 	config := &fst.Config{
-		ID:   app.ID,
+		ID: app.ID,
+
 		Path: argv[0],
 		Args: argv,
-		Confinement: fst.ConfinementConfig{
+
-			AppID:    app.AppID,
+		Enablements: app.Enablements,
-			Groups:   app.Groups,
+
-			Username: "fortify",
+		SystemBus:     app.SystemBus,
-			Inner:    path.Join("/data/data", app.ID),
+		SessionBus:    app.SessionBus,
-			Outer:    pathSet.homeDir,
+		DirectWayland: app.DirectWayland,
-			Sandbox: &fst.SandboxConfig{
+
-				Hostname:      formatHostname(app.Name),
+		Username: "fortify",
-				Devel:         app.Devel,
+		Shell:    shellPath,
-				Userns:        app.Userns,
+		Data:     pathSet.homeDir,
-				Net:           app.Net,
+		Dir:      path.Join("/data/data", app.ID),
-				Dev:           app.Dev,
+
-				Tty:           app.Tty || flagDropShell,
+		Identity: app.Identity,
-				MapRealUID:    app.MapRealUID,
+		Groups:   app.Groups,
-				DirectWayland: app.DirectWayland,
+
-				Filesystem: []*fst.FilesystemConfig{
+		Container: &fst.ContainerConfig{
-					{Src: path.Join(pathSet.nixPath, "store"), Dst: "/nix/store", Must: true},
+			Hostname:   formatHostname(app.Name),
-					{Src: pathSet.metaPath, Dst: path.Join(fst.Tmp, "app"), Must: true},
+			Devel:      app.Devel,
-					{Src: "/etc/resolv.conf"},
+			Userns:     app.Userns,
-					{Src: "/sys/block"},
+			Net:        app.Net,
-					{Src: "/sys/bus"},
+			Device:     app.Device,
-					{Src: "/sys/class"},
+			Tty:        app.Tty || flagDropShell,
-					{Src: "/sys/dev"},
+			MapRealUID: app.MapRealUID,
-					{Src: "/sys/devices"},
+			Filesystem: []*fst.FilesystemConfig{
-				},
+				{Src: path.Join(pathSet.nixPath, "store"), Dst: "/nix/store", Must: true},
-				Link: [][2]string{
+				{Src: pathSet.metaPath, Dst: path.Join(fst.Tmp, "app"), Must: true},
-					{app.CurrentSystem, "/run/current-system"},
+				{Src: "/etc/resolv.conf"},
-					{"/run/current-system/sw/bin", "/bin"},
+				{Src: "/sys/block"},
-					{"/run/current-system/sw/bin", "/usr/bin"},
+				{Src: "/sys/bus"},
-				},
+				{Src: "/sys/class"},
-				Etc:     path.Join(pathSet.cacheDir, "etc"),
+				{Src: "/sys/dev"},
-				AutoEtc: true,
+				{Src: "/sys/devices"},
 			},
-			ExtraPerms: []*fst.ExtraPermConfig{
+			Link: [][2]string{
-				{Path: dataHome, Execute: true},
+				{app.CurrentSystem, "/run/current-system"},
-				{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
+				{"/run/current-system/sw/bin", "/bin"},
+				{"/run/current-system/sw/bin", "/usr/bin"},
 			},
-			SystemBus:   app.SystemBus,
+			Etc:     path.Join(pathSet.cacheDir, "etc"),
-			SessionBus:  app.SessionBus,
+			AutoEtc: true,
-			Enablements: app.Enablements,
+		},
+		ExtraPerms: []*fst.ExtraPermConfig{
+			{Path: dataHome, Execute: true},
+			{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
 		},
 	}
 	if app.Multiarch {
-		config.Confinement.Sandbox.Seccomp |= seccomp.FlagMultiarch
+		config.Container.Seccomp |= seccomp.FilterMultiarch
 	}
 	if app.Bluetooth {
-		config.Confinement.Sandbox.Seccomp |= seccomp.FlagBluetooth
+		config.Container.Seccomp |= seccomp.FilterBluetooth
 	}
 	return config
 }

cmd/fpkg/build.nix

@@ -31,7 +31,7 @@
   '',
 
   id ? name,
-  app_id ? throw "app_id is required",
+  identity ? throw "identity is required",
   groups ? [ ],
   userns ? false,
   net ? true,
@@ -147,7 +147,7 @@ let
       name
       version
       id
-      app_id
+      identity
       launcher
       groups
       userns

cmd/fpkg/main.go

@@ -13,7 +13,7 @@ import (
 	"git.gensokyo.uk/security/fortify/command"
 	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/internal"
-	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/instance"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/internal/sys"
 	"git.gensokyo.uk/security/fortify/sandbox"
@@ -62,7 +62,7 @@ func main() {
 		Flag(&flagVerbose, "v", command.BoolFlag(false), "Print debug messages to the console").
 		Flag(&flagDropShell, "s", command.BoolFlag(false), "Drop to a shell in place of next fortify action")
 
-	c.Command("shim", command.UsageInternal, func([]string) error { app.ShimMain(); return errSuccess })
+	c.Command("shim", command.UsageInternal, func([]string) error { instance.ShimMain(); return errSuccess })
 
 	{
 		var (
@@ -157,11 +157,11 @@ func main() {
 					return errSuccess
 				}
 
-				// AppID determines uid
+				// identity determines uid
-				if a.AppID != bundle.AppID {
+				if a.Identity != bundle.Identity {
 					cleanup()
-					log.Printf("package %q app id %d differs from installed %d",
+					log.Printf("package %q identity %d differs from installed %d",
-						pkgPath, bundle.AppID, a.AppID)
+						pkgPath, bundle.Identity, a.Identity)
 					return syscall.EBADE
 				}
 
@@ -292,7 +292,7 @@ func main() {
 						"--override-input nixpkgs path:/etc/nixpkgs " +
 						"path:" + a.NixGL + "#nixVulkanNvidia",
 				}, true, func(config *fst.Config) *fst.Config {
-					config.Confinement.Sandbox.Filesystem = append(config.Confinement.Sandbox.Filesystem, []*fst.FilesystemConfig{
+					config.Container.Filesystem = append(config.Container.Filesystem, []*fst.FilesystemConfig{
 						{Src: "/etc/resolv.conf"},
 						{Src: "/sys/block"},
 						{Src: "/sys/bus"},
@@ -324,7 +324,7 @@ func main() {
 			*/
 
 			if a.GPU {
-				config.Confinement.Sandbox.Filesystem = append(config.Confinement.Sandbox.Filesystem,
+				config.Container.Filesystem = append(config.Container.Filesystem,
 					&fst.FilesystemConfig{Src: path.Join(pathSet.nixPath, ".nixGL"), Dst: path.Join(fst.Tmp, "nixGL")})
 				appendGPUFilesystem(config)
 			}

cmd/fpkg/paths.go

@@ -72,7 +72,7 @@ func pathSetByApp(id string) *appPathSet {
 }
 
 func appendGPUFilesystem(config *fst.Config) {
-	config.Confinement.Sandbox.Filesystem = append(config.Confinement.Sandbox.Filesystem, []*fst.FilesystemConfig{
+	config.Container.Filesystem = append(config.Container.Filesystem, []*fst.FilesystemConfig{
 		// flatpak commit 763a686d874dd668f0236f911de00b80766ffe79
 		{Src: "/dev/dri", Device: true},
 		// mali

cmd/fpkg/proc.go

@@ -6,23 +6,24 @@ import (
 
 	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/instance"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
 func mustRunApp(ctx context.Context, config *fst.Config, beforeFail func()) {
-	rs := new(fst.RunState)
+	rs := new(app.RunState)
-	a := app.MustNew(ctx, std)
+	a := instance.MustNew(instance.ISetuid, ctx, std)
 
+	var code int
 	if sa, err := a.Seal(config); err != nil {
 		fmsg.PrintBaseError(err, "cannot seal app:")
-		rs.ExitCode = 1
+		code = 1
 	} else {
-		// this updates ExitCode
+		code = instance.PrintRunStateErr(instance.ISetuid, rs, sa.Run(rs))
-		app.PrintRunStateErr(rs, sa.Run(rs))
 	}
 
-	if rs.ExitCode != 0 {
+	if code != 0 {
 		beforeFail()
-		os.Exit(rs.ExitCode)
+		os.Exit(code)
 	}
 }

cmd/fpkg/test/foot.nix

@@ -10,7 +10,7 @@ buildPackage {
   name = "foot";
   inherit (foot) version;
 
-  app_id = 2;
+  identity = 2;
   id = "org.codeberg.dnkl.foot";
 
   modules = [

cmd/fpkg/test/test.py

@@ -65,8 +65,8 @@ def check_state(name, enablements):
     if len(config['args']) != 1 or not (config['args'][0].startswith("/nix/store/")) or f"fortify-{name}-" not in (config['args'][0]):
         raise Exception(f"unexpected args {instance['config']['args']}")
 
-    if config['confinement']['enablements'] != enablements:
+    if config['enablements'] != enablements:
-        raise Exception(f"unexpected enablements {instance['config']['confinement']['enablements']}")
+        raise Exception(f"unexpected enablements {instance['config']['enablements']}")
 
 
 start_all()

cmd/fpkg/with.go

@@ -16,7 +16,8 @@ func withNixDaemon(
 	app *appInfo, pathSet *appPathSet, dropShell bool, beforeFail func(),
 ) {
 	mustRunAppDropShell(ctx, updateConfig(&fst.Config{
-		ID:   app.ID,
+		ID: app.ID,
+
 		Path: shellPath,
 		Args: []string{shellPath, "-lc", "rm -f /nix/var/nix/daemon-socket/socket && " +
 			// start nix-daemon
@@ -29,32 +30,34 @@ func withNixDaemon(
 			// terminate nix-daemon
 			" && pkill nix-daemon",
 		},
-		Confinement: fst.ConfinementConfig{
+
-			AppID:    app.AppID,
+		Username: "fortify",
-			Username: "fortify",
+		Shell:    shellPath,
-			Inner:    path.Join("/data/data", app.ID),
+		Data:     pathSet.homeDir,
-			Outer:    pathSet.homeDir,
+		Dir:      path.Join("/data/data", app.ID),
-			Sandbox: &fst.SandboxConfig{
+		ExtraPerms: []*fst.ExtraPermConfig{
-				Hostname: formatHostname(app.Name) + "-" + action,
+			{Path: dataHome, Execute: true},
-				Userns:   true, // nix sandbox requires userns
+			{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
-				Net:      net,
+		},
-				Seccomp:  seccomp.FlagMultiarch,
+
-				Tty:      dropShell,
+		Identity: app.Identity,
-				Filesystem: []*fst.FilesystemConfig{
+
-					{Src: pathSet.nixPath, Dst: "/nix", Write: true, Must: true},
+		Container: &fst.ContainerConfig{
-				},
+			Hostname: formatHostname(app.Name) + "-" + action,
-				Link: [][2]string{
+			Userns:   true, // nix sandbox requires userns
-					{app.CurrentSystem, "/run/current-system"},
+			Net:      net,
-					{"/run/current-system/sw/bin", "/bin"},
+			Seccomp:  seccomp.FilterMultiarch,
-					{"/run/current-system/sw/bin", "/usr/bin"},
+			Tty:      dropShell,
-				},
+			Filesystem: []*fst.FilesystemConfig{
-				Etc:     path.Join(pathSet.cacheDir, "etc"),
+				{Src: pathSet.nixPath, Dst: "/nix", Write: true, Must: true},
-				AutoEtc: true,
 			},
-			ExtraPerms: []*fst.ExtraPermConfig{
+			Link: [][2]string{
-				{Path: dataHome, Execute: true},
+				{app.CurrentSystem, "/run/current-system"},
-				{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
+				{"/run/current-system/sw/bin", "/bin"},
+				{"/run/current-system/sw/bin", "/usr/bin"},
 			},
+			Etc:     path.Join(pathSet.cacheDir, "etc"),
+			AutoEtc: true,
 		},
 	}), dropShell, beforeFail)
 }
@@ -64,35 +67,38 @@ func withCacheDir(
 	action string, command []string, workDir string,
 	app *appInfo, pathSet *appPathSet, dropShell bool, beforeFail func()) {
 	mustRunAppDropShell(ctx, &fst.Config{
-		ID:   app.ID,
+		ID: app.ID,
+
 		Path: shellPath,
 		Args: []string{shellPath, "-lc", strings.Join(command, " && ")},
-		Confinement: fst.ConfinementConfig{
+
-			AppID:    app.AppID,
+		Username: "nixos",
-			Username: "nixos",
+		Shell:    shellPath,
-			Inner:    path.Join("/data/data", app.ID, "cache"),
+		Data:     pathSet.cacheDir, // this also ensures cacheDir via shim
-			Outer:    pathSet.cacheDir, // this also ensures cacheDir via shim
+		Dir:      path.Join("/data/data", app.ID, "cache"),
-			Sandbox: &fst.SandboxConfig{
+		ExtraPerms: []*fst.ExtraPermConfig{
-				Hostname: formatHostname(app.Name) + "-" + action,
+			{Path: dataHome, Execute: true},
-				Seccomp:  seccomp.FlagMultiarch,
+			{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
-				Tty:      dropShell,
+			{Path: workDir, Execute: true},
-				Filesystem: []*fst.FilesystemConfig{
+		},
-					{Src: path.Join(workDir, "nix"), Dst: "/nix", Must: true},
+
-					{Src: workDir, Dst: path.Join(fst.Tmp, "bundle"), Must: true},
+		Identity: app.Identity,
-				},
+
-				Link: [][2]string{
+		Container: &fst.ContainerConfig{
-					{app.CurrentSystem, "/run/current-system"},
+			Hostname: formatHostname(app.Name) + "-" + action,
-					{"/run/current-system/sw/bin", "/bin"},
+			Seccomp:  seccomp.FilterMultiarch,
-					{"/run/current-system/sw/bin", "/usr/bin"},
+			Tty:      dropShell,
-				},
+			Filesystem: []*fst.FilesystemConfig{
-				Etc:     path.Join(workDir, "etc"),
+				{Src: path.Join(workDir, "nix"), Dst: "/nix", Must: true},
-				AutoEtc: true,
+				{Src: workDir, Dst: path.Join(fst.Tmp, "bundle"), Must: true},
 			},
-			ExtraPerms: []*fst.ExtraPermConfig{
+			Link: [][2]string{
-				{Path: dataHome, Execute: true},
+				{app.CurrentSystem, "/run/current-system"},
-				{Ensure: true, Path: pathSet.baseDir, Read: true, Write: true, Execute: true},
+				{"/run/current-system/sw/bin", "/bin"},
-				{Path: workDir, Execute: true},
+				{"/run/current-system/sw/bin", "/usr/bin"},
 			},
+			Etc:     path.Join(workDir, "etc"),
+			AutoEtc: true,
 		},
 	}, dropShell, beforeFail)
 }

dbus/dbus_test.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+	"syscall"
 	"testing"
 	"time"
 
@@ -71,7 +72,7 @@ func TestProxy_Seal(t *testing.T) {
 	for id, tc := range testCasePairs() {
 		t.Run("create seal for "+id, func(t *testing.T) {
 			p := dbus.New(tc[0].bus, tc[1].bus)
-			if err := p.Seal(tc[0].c, tc[1].c); (errors.Is(err, helper.ErrContainsNull)) != tc[0].wantErr {
+			if err := p.Seal(tc[0].c, tc[1].c); (errors.Is(err, syscall.EINVAL)) != tc[0].wantErr {
 				t.Errorf("Seal(%p, %p) error = %v, wantErr %v",
 					tc[0].c, tc[1].c,
 					err, tc[0].wantErr)

dbus/proc.go

@@ -63,7 +63,7 @@ func (p *Proxy) Start(ctx context.Context, output io.Writer, useSandbox bool) er
 			c, toolPath,
 			p.seal, true,
 			argF, func(container *sandbox.Container) {
-				container.Seccomp |= seccomp.FlagMultiarch
+				container.Seccomp |= seccomp.FilterMultiarch
 				container.Hostname = "fortify-dbus"
 				container.CommandContext = p.CommandContext
 				if output != nil {

flake.lock

@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1742234739,
+        "lastModified": 1742655702,
-        "narHash": "sha256-zFL6zsf/5OztR1NSNQF33dvS1fL/BzVUjabZq4qrtY4=",
+        "narHash": "sha256-jbqlw4sPArFtNtA1s3kLg7/A4fzP4GLk9bGbtUJg0JQ=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "f6af7280a3390e65c2ad8fd059cdc303426cbd59",
+        "rev": "0948aeedc296f964140d9429223c7e4a0702a1ff",
         "type": "github"
       },
       "original": {
@@ -23,11 +23,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1742512142,
+        "lastModified": 1743231893,
-        "narHash": "sha256-8XfURTDxOm6+33swQJu/hx6xw1Tznl8vJJN5HwVqckg=",
+        "narHash": "sha256-tpJsHMUPEhEnzySoQxx7+kA+KUtgWqvlcUBqROYNNt0=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "7105ae3957700a9646cc4b766f5815b23ed0c682",
+        "rev": "c570c1f5304493cafe133b8d843c7c1c4a10d3a6",
         "type": "github"
       },
       "original": {

flake.nix

@@ -58,12 +58,19 @@
         in
         {
           fortify = callPackage ./test { inherit system self; };
-          fpkg = callPackage ./cmd/fpkg/test { inherit system self; };
           race = callPackage ./test {
             inherit system self;
             withRace = true;
           };
 
+          sandbox = callPackage ./test/sandbox { inherit self; };
+          sandbox-race = callPackage ./test/sandbox {
+            inherit self;
+            withRace = true;
+          };
+
+          fpkg = callPackage ./cmd/fpkg/test { inherit system self; };
+
           formatting = runCommandLocal "check-formatting" { nativeBuildInputs = [ nixfmt-rfc-style ]; } ''
             cd ${./.}
 

fst/app.go

@@ -1,47 +0,0 @@
-// Package fst exports shared fortify types.
-package fst
-
-import (
-	"time"
-)
-
-type App interface {
-	// ID returns a copy of [fst.ID] held by App.
-	ID() ID
-
-	// Seal determines the outcome of config as a [SealedApp].
-	// The value of config might be overwritten and must not be used again.
-	Seal(config *Config) (SealedApp, error)
-
-	String() string
-}
-
-type SealedApp interface {
-	// Run commits sealed system setup and starts the app process.
-	Run(rs *RunState) error
-}
-
-// RunState stores the outcome of a call to [SealedApp.Run].
-type RunState struct {
-	// Time is the exact point in time where the process was created.
-	// Location must be set to UTC.
-	//
-	// Time is nil if no process was ever created.
-	Time *time.Time
-	// ExitCode is the value returned by shim.
-	ExitCode int
-	// RevertErr is stored by the deferred revert call.
-	RevertErr error
-	// WaitErr is error returned by the underlying wait syscall.
-	WaitErr error
-}
-
-// Paths contains environment-dependent paths used by fortify.
-type Paths struct {
-	// path to shared directory (usually `/tmp/fortify.%d`)
-	SharePath string `json:"share_path"`
-	// XDG_RUNTIME_DIR value (usually `/run/user/%d`)
-	RuntimePath string `json:"runtime_path"`
-	// application runtime directory (usually `/run/user/%d/fortify`)
-	RunDirPath string `json:"run_dir_path"`
-}

fst/config.go

@@ -1,14 +1,14 @@
+// Package fst exports shared fortify types.
 package fst
 
 import (
 	"git.gensokyo.uk/security/fortify/dbus"
-	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
 	"git.gensokyo.uk/security/fortify/system"
 )
 
 const Tmp = "/.fortify"
 
-// Config is used to seal an app
+// Config is used to seal an app implementation.
 type Config struct {
 	// reverse-DNS style arbitrary identifier string from config;
 	// passed to wayland security-context-v1 as application ID
@@ -20,37 +20,40 @@ type Config struct {
 	// final args passed to container init
 	Args []string `json:"args"`
 
-	Confinement ConfinementConfig `json:"confinement"`
+	// system services to make available in the container
-}
+	Enablements system.Enablement `json:"enablements"`
+
+	// session D-Bus proxy configuration;
+	// nil makes session bus proxy assume built-in defaults
+	SessionBus *dbus.Config `json:"session_bus,omitempty"`
+	// system D-Bus proxy configuration;
+	// nil disables system bus proxy
+	SystemBus *dbus.Config `json:"system_bus,omitempty"`
+	// direct access to wayland socket; when this gets set no attempt is made to attach security-context-v1
+	// and the bare socket is mounted to the sandbox
+	DirectWayland bool `json:"direct_wayland,omitempty"`
 
-// ConfinementConfig defines fortified child's confinement
-type ConfinementConfig struct {
-	// numerical application id, determines uid in the init namespace
-	AppID int `json:"app_id"`
-	// list of supplementary groups to inherit
-	Groups []string `json:"groups"`
 	// passwd username in container, defaults to passwd name of target uid or chronos
 	Username string `json:"username,omitempty"`
-	// home directory in container, empty for outer
+	// absolute path to shell, empty for host shell
-	Inner string `json:"home_inner"`
+	Shell string `json:"shell,omitempty"`
-	// home directory in init namespace
+	// absolute path to home directory in the init mount namespace
-	Outer string `json:"home"`
+	Data string `json:"data"`
-	// abstract sandbox configuration
+	// directory to enter and use as home in the container mount namespace, empty for Data
-	Sandbox *SandboxConfig `json:"sandbox"`
+	Dir string `json:"dir"`
-	// extra acl ops, runs after everything else
+	// extra acl ops, dispatches before container init
 	ExtraPerms []*ExtraPermConfig `json:"extra_perms,omitempty"`
 
-	// reference to a system D-Bus proxy configuration,
+	// numerical application id, used for init user namespace credentials
-	// nil value disables system bus proxy
+	Identity int `json:"identity"`
-	SystemBus *dbus.Config `json:"system_bus,omitempty"`
+	// list of supplementary groups inherited by container processes
-	// reference to a session D-Bus proxy configuration,
+	Groups []string `json:"groups"`
-	// nil value makes session bus proxy assume built-in defaults
-	SessionBus *dbus.Config `json:"session_bus,omitempty"`
 
-	// system resources to expose to the container
+	// abstract container configuration baseline
-	Enablements system.Enablement `json:"enablements"`
+	Container *ContainerConfig `json:"container"`
 }
 
+// ExtraPermConfig describes an acl update op.
 type ExtraPermConfig struct {
 	Ensure  bool   `json:"ensure,omitempty"`
 	Path    string `json:"path"`
@@ -78,82 +81,3 @@ func (e *ExtraPermConfig) String() string {
 	}
 	return string(buf)
 }
-
-// Template returns a fully populated instance of Config.
-func Template() *Config {
-	return &Config{
-		ID:   "org.chromium.Chromium",
-		Path: "/run/current-system/sw/bin/chromium",
-		Args: []string{
-			"chromium",
-			"--ignore-gpu-blocklist",
-			"--disable-smooth-scrolling",
-			"--enable-features=UseOzonePlatform",
-			"--ozone-platform=wayland",
-		},
-		Confinement: ConfinementConfig{
-			AppID:    9,
-			Groups:   []string{"video"},
-			Username: "chronos",
-			Outer:    "/var/lib/persist/home/org.chromium.Chromium",
-			Inner:    "/var/lib/fortify",
-			Sandbox: &SandboxConfig{
-				Hostname:      "localhost",
-				Devel:         true,
-				Userns:        true,
-				Net:           true,
-				Dev:           true,
-				Seccomp:       seccomp.FlagMultiarch,
-				Tty:           true,
-				Multiarch:     true,
-				MapRealUID:    true,
-				DirectWayland: false,
-				// example API credentials pulled from Google Chrome
-				// DO NOT USE THESE IN A REAL BROWSER
-				Env: map[string]string{
-					"GOOGLE_API_KEY":               "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
-					"GOOGLE_DEFAULT_CLIENT_ID":     "77185425430.apps.googleusercontent.com",
-					"GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT",
-				},
-				Filesystem: []*FilesystemConfig{
-					{Src: "/nix/store"},
-					{Src: "/run/current-system"},
-					{Src: "/run/opengl-driver"},
-					{Src: "/var/db/nix-channels"},
-					{Src: "/var/lib/fortify/u0/org.chromium.Chromium",
-						Dst: "/data/data/org.chromium.Chromium", Write: true, Must: true},
-					{Src: "/dev/dri", Device: true},
-				},
-				Link:    [][2]string{{"/run/user/65534", "/run/user/150"}},
-				Etc:     "/etc",
-				AutoEtc: true,
-				Cover:   []string{"/var/run/nscd"},
-			},
-			ExtraPerms: []*ExtraPermConfig{
-				{Path: "/var/lib/fortify/u0", Ensure: true, Execute: true},
-				{Path: "/var/lib/fortify/u0/org.chromium.Chromium", Read: true, Write: true, Execute: true},
-			},
-			SystemBus: &dbus.Config{
-				See:       nil,
-				Talk:      []string{"org.bluez", "org.freedesktop.Avahi", "org.freedesktop.UPower"},
-				Own:       nil,
-				Call:      nil,
-				Broadcast: nil,
-				Log:       false,
-				Filter:    true,
-			},
-			SessionBus: &dbus.Config{
-				See: nil,
-				Talk: []string{"org.freedesktop.Notifications", "org.freedesktop.FileManager1", "org.freedesktop.ScreenSaver",
-					"org.freedesktop.secrets", "org.kde.kwalletd5", "org.kde.kwalletd6", "org.gnome.SessionManager"},
-				Own: []string{"org.chromium.Chromium.*", "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-					"org.mpris.MediaPlayer2.chromium.*"},
-				Call:      map[string]string{"org.freedesktop.portal.*": "*"},
-				Broadcast: map[string]string{"org.freedesktop.portal.*": "@/org/freedesktop/portal/*"},
-				Log:       false,
-				Filter:    true,
-			},
-			Enablements: system.EWayland | system.EDBus | system.EPulse,
-		},
-	}
-}

fst/container.go

@@ -0,0 +1,59 @@
+package fst
+
+import (
+	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
+)
+
+type (
+	// ContainerConfig describes the container configuration baseline to which the app implementation adds upon.
+	ContainerConfig struct {
+		// container hostname
+		Hostname string `json:"hostname,omitempty"`
+
+		// extra seccomp flags
+		Seccomp seccomp.FilterOpts `json:"seccomp"`
+		// allow ptrace and friends
+		Devel bool `json:"devel,omitempty"`
+		// allow userns creation in container
+		Userns bool `json:"userns,omitempty"`
+		// share host net namespace
+		Net bool `json:"net,omitempty"`
+		// allow dangerous terminal I/O
+		Tty bool `json:"tty,omitempty"`
+		// allow multiarch
+		Multiarch bool `json:"multiarch,omitempty"`
+
+		// initial process environment variables
+		Env map[string]string `json:"env"`
+		// map target user uid to privileged user uid in the user namespace
+		MapRealUID bool `json:"map_real_uid"`
+
+		// pass through all devices
+		Device bool `json:"device,omitempty"`
+		// container host filesystem bind mounts
+		Filesystem []*FilesystemConfig `json:"filesystem"`
+		// create symlinks inside container filesystem
+		Link [][2]string `json:"symlink"`
+
+		// read-only /etc directory
+		Etc string `json:"etc,omitempty"`
+		// automatically set up /etc symlinks
+		AutoEtc bool `json:"auto_etc"`
+		// cover these paths or create them if they do not already exist
+		Cover []string `json:"cover"`
+	}
+
+	// FilesystemConfig is an abstract representation of a bind mount.
+	FilesystemConfig struct {
+		// mount point in container, same as src if empty
+		Dst string `json:"dst,omitempty"`
+		// host filesystem path to make available to the container
+		Src string `json:"src"`
+		// do not mount filesystem read-only
+		Write bool `json:"write,omitempty"`
+		// do not disable device files
+		Device bool `json:"dev,omitempty"`
+		// fail if the bind mount cannot be established for any reason
+		Must bool `json:"require,omitempty"`
+	}
+)

fst/sandbox.go

@@ -1,282 +0,0 @@
-package fst
-
-import (
-	"errors"
-	"fmt"
-	"io/fs"
-	"maps"
-	"path"
-	"slices"
-	"syscall"
-
-	"git.gensokyo.uk/security/fortify/dbus"
-	"git.gensokyo.uk/security/fortify/sandbox"
-	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
-)
-
-// SandboxConfig describes resources made available to the sandbox.
-type (
-	SandboxConfig struct {
-		// container hostname
-		Hostname string `json:"hostname,omitempty"`
-
-		// extra seccomp flags
-		Seccomp seccomp.SyscallOpts `json:"seccomp"`
-		// allow ptrace and friends
-		Devel bool `json:"devel,omitempty"`
-		// allow userns creation in container
-		Userns bool `json:"userns,omitempty"`
-		// share host net namespace
-		Net bool `json:"net,omitempty"`
-		// expose main process tty
-		Tty bool `json:"tty,omitempty"`
-		// allow multiarch
-		Multiarch bool `json:"multiarch,omitempty"`
-
-		// initial process environment variables
-		Env map[string]string `json:"env"`
-		// map target user uid to privileged user uid in the user namespace
-		MapRealUID bool `json:"map_real_uid"`
-
-		// expose all devices
-		Dev bool `json:"dev,omitempty"`
-		// container host filesystem bind mounts
-		Filesystem []*FilesystemConfig `json:"filesystem"`
-		// create symlinks inside container filesystem
-		Link [][2]string `json:"symlink"`
-
-		// direct access to wayland socket; when this gets set no attempt is made to attach security-context-v1
-		// and the bare socket is mounted to the sandbox
-		DirectWayland bool `json:"direct_wayland,omitempty"`
-
-		// read-only /etc directory
-		Etc string `json:"etc,omitempty"`
-		// automatically set up /etc symlinks
-		AutoEtc bool `json:"auto_etc"`
-		// cover these paths or create them if they do not already exist
-		Cover []string `json:"cover"`
-	}
-
-	// SandboxSys encapsulates system functions used during [sandbox.Container] initialisation.
-	SandboxSys interface {
-		Getuid() int
-		Getgid() int
-		Paths() Paths
-		ReadDir(name string) ([]fs.DirEntry, error)
-		EvalSymlinks(path string) (string, error)
-
-		Println(v ...any)
-		Printf(format string, v ...any)
-	}
-
-	// FilesystemConfig is a representation of [sandbox.BindMount].
-	FilesystemConfig struct {
-		// mount point in container, same as src if empty
-		Dst string `json:"dst,omitempty"`
-		// host filesystem path to make available to the container
-		Src string `json:"src"`
-		// do not mount filesystem read-only
-		Write bool `json:"write,omitempty"`
-		// do not disable device files
-		Device bool `json:"dev,omitempty"`
-		// fail if the bind mount cannot be established for any reason
-		Must bool `json:"require,omitempty"`
-	}
-)
-
-// ToContainer initialises [sandbox.Params] via [SandboxConfig].
-// Note that remaining container setup must be queued by the [App] implementation.
-func (s *SandboxConfig) ToContainer(sys SandboxSys, uid, gid *int) (*sandbox.Params, map[string]string, error) {
-	if s == nil {
-		return nil, nil, syscall.EBADE
-	}
-
-	container := &sandbox.Params{
-		Hostname: s.Hostname,
-		Ops:      new(sandbox.Ops),
-		Seccomp:  s.Seccomp,
-	}
-
-	/* this is only 4 KiB of memory on a 64-bit system,
-	permissive defaults on NixOS results in around 100 entries
-	so this capacity should eliminate copies for most setups */
-	*container.Ops = slices.Grow(*container.Ops, 1<<8)
-
-	if s.Devel {
-		container.Flags |= sandbox.FAllowDevel
-	}
-	if s.Userns {
-		container.Flags |= sandbox.FAllowUserns
-	}
-	if s.Net {
-		container.Flags |= sandbox.FAllowNet
-	}
-	if s.Tty {
-		container.Flags |= sandbox.FAllowTTY
-	}
-
-	if s.MapRealUID {
-		/* some programs fail to connect to dbus session running as a different uid
-		so this workaround is introduced to map priv-side caller uid in container */
-		container.Uid = sys.Getuid()
-		*uid = container.Uid
-		container.Gid = sys.Getgid()
-		*gid = container.Gid
-	} else {
-		*uid = sandbox.OverflowUid()
-		*gid = sandbox.OverflowGid()
-	}
-
-	container.
-		Proc("/proc").
-		Tmpfs(Tmp, 1<<12, 0755)
-
-	if !s.Dev {
-		container.Dev("/dev").Mqueue("/dev/mqueue")
-	} else {
-		container.Bind("/dev", "/dev", sandbox.BindDevice)
-	}
-
-	/* retrieve paths and hide them if they're made available in the sandbox;
-	this feature tries to improve user experience of permissive defaults, and
-	to warn about issues in custom configuration; it is NOT a security feature
-	and should not be treated as such, ALWAYS be careful with what you bind */
-	var hidePaths []string
-	sc := sys.Paths()
-	hidePaths = append(hidePaths, sc.RuntimePath, sc.SharePath)
-	_, systemBusAddr := dbus.Address()
-	if entries, err := dbus.Parse([]byte(systemBusAddr)); err != nil {
-		return nil, nil, err
-	} else {
-		// there is usually only one, do not preallocate
-		for _, entry := range entries {
-			if entry.Method != "unix" {
-				continue
-			}
-			for _, pair := range entry.Values {
-				if pair[0] == "path" {
-					if path.IsAbs(pair[1]) {
-						// get parent dir of socket
-						dir := path.Dir(pair[1])
-						if dir == "." || dir == "/" {
-							sys.Printf("dbus socket %q is in an unusual location", pair[1])
-						}
-						hidePaths = append(hidePaths, dir)
-					} else {
-						sys.Printf("dbus socket %q is not absolute", pair[1])
-					}
-				}
-			}
-		}
-	}
-	hidePathMatch := make([]bool, len(hidePaths))
-	for i := range hidePaths {
-		if err := evalSymlinks(sys, &hidePaths[i]); err != nil {
-			return nil, nil, err
-		}
-	}
-
-	for _, c := range s.Filesystem {
-		if c == nil {
-			continue
-		}
-
-		if !path.IsAbs(c.Src) {
-			return nil, nil, fmt.Errorf("src path %q is not absolute", c.Src)
-		}
-
-		dest := c.Dst
-		if c.Dst == "" {
-			dest = c.Src
-		} else if !path.IsAbs(dest) {
-			return nil, nil, fmt.Errorf("dst path %q is not absolute", dest)
-		}
-
-		srcH := c.Src
-		if err := evalSymlinks(sys, &srcH); err != nil {
-			return nil, nil, err
-		}
-
-		for i := range hidePaths {
-			// skip matched entries
-			if hidePathMatch[i] {
-				continue
-			}
-
-			if ok, err := deepContainsH(srcH, hidePaths[i]); err != nil {
-				return nil, nil, err
-			} else if ok {
-				hidePathMatch[i] = true
-				sys.Printf("hiding paths from %q", c.Src)
-			}
-		}
-
-		var flags int
-		if c.Write {
-			flags |= sandbox.BindWritable
-		}
-		if c.Device {
-			flags |= sandbox.BindDevice | sandbox.BindWritable
-		}
-		if !c.Must {
-			flags |= sandbox.BindOptional
-		}
-		container.Bind(c.Src, dest, flags)
-	}
-
-	// cover matched paths
-	for i, ok := range hidePathMatch {
-		if ok {
-			container.Tmpfs(hidePaths[i], 1<<13, 0755)
-		}
-	}
-
-	for _, l := range s.Link {
-		container.Link(l[0], l[1])
-	}
-
-	// perf: this might work better if implemented as a setup op in container init
-	if !s.AutoEtc {
-		if s.Etc != "" {
-			container.Bind(s.Etc, "/etc", 0)
-		}
-	} else {
-		etcPath := s.Etc
-		if etcPath == "" {
-			etcPath = "/etc"
-		}
-		container.Bind(etcPath, Tmp+"/etc", 0)
-
-		// link host /etc contents to prevent dropping passwd/group bind mounts
-		if d, err := sys.ReadDir(etcPath); err != nil {
-			return nil, nil, err
-		} else {
-			for _, ent := range d {
-				n := ent.Name()
-				switch n {
-				case "passwd":
-				case "group":
-
-				case "mtab":
-					container.Link("/proc/mounts", "/etc/"+n)
-				default:
-					container.Link(Tmp+"/etc/"+n, "/etc/"+n)
-				}
-			}
-		}
-	}
-
-	return container, maps.Clone(s.Env), nil
-}
-
-func evalSymlinks(sys SandboxSys, v *string) error {
-	if p, err := sys.EvalSymlinks(*v); err != nil {
-		if !errors.Is(err, fs.ErrNotExist) {
-			return err
-		}
-		sys.Printf("path %q does not yet exist", *v)
-	} else {
-		*v = p
-	}
-	return nil
-}

fst/template.go

@@ -0,0 +1,91 @@
+package fst
+
+import (
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
+	"git.gensokyo.uk/security/fortify/system"
+)
+
+// Template returns a fully populated instance of Config.
+func Template() *Config {
+	return &Config{
+		ID: "org.chromium.Chromium",
+
+		Path: "/run/current-system/sw/bin/chromium",
+		Args: []string{
+			"chromium",
+			"--ignore-gpu-blocklist",
+			"--disable-smooth-scrolling",
+			"--enable-features=UseOzonePlatform",
+			"--ozone-platform=wayland",
+		},
+
+		Enablements: system.EWayland | system.EDBus | system.EPulse,
+
+		SessionBus: &dbus.Config{
+			See: nil,
+			Talk: []string{"org.freedesktop.Notifications", "org.freedesktop.FileManager1", "org.freedesktop.ScreenSaver",
+				"org.freedesktop.secrets", "org.kde.kwalletd5", "org.kde.kwalletd6", "org.gnome.SessionManager"},
+			Own: []string{"org.chromium.Chromium.*", "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+				"org.mpris.MediaPlayer2.chromium.*"},
+			Call:      map[string]string{"org.freedesktop.portal.*": "*"},
+			Broadcast: map[string]string{"org.freedesktop.portal.*": "@/org/freedesktop/portal/*"},
+			Log:       false,
+			Filter:    true,
+		},
+		SystemBus: &dbus.Config{
+			See:       nil,
+			Talk:      []string{"org.bluez", "org.freedesktop.Avahi", "org.freedesktop.UPower"},
+			Own:       nil,
+			Call:      nil,
+			Broadcast: nil,
+			Log:       false,
+			Filter:    true,
+		},
+		DirectWayland: false,
+
+		Username: "chronos",
+		Shell:    "/run/current-system/sw/bin/zsh",
+		Data:     "/var/lib/fortify/u0/org.chromium.Chromium",
+		Dir:      "/data/data/org.chromium.Chromium",
+		ExtraPerms: []*ExtraPermConfig{
+			{Path: "/var/lib/fortify/u0", Ensure: true, Execute: true},
+			{Path: "/var/lib/fortify/u0/org.chromium.Chromium", Read: true, Write: true, Execute: true},
+		},
+
+		Identity: 9,
+		Groups:   []string{"video", "dialout", "plugdev"},
+
+		Container: &ContainerConfig{
+			Hostname:   "localhost",
+			Devel:      true,
+			Userns:     true,
+			Net:        true,
+			Device:     true,
+			Seccomp:    seccomp.FilterMultiarch,
+			Tty:        true,
+			Multiarch:  true,
+			MapRealUID: true,
+			// example API credentials pulled from Google Chrome
+			// DO NOT USE THESE IN A REAL BROWSER
+			Env: map[string]string{
+				"GOOGLE_API_KEY":               "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
+				"GOOGLE_DEFAULT_CLIENT_ID":     "77185425430.apps.googleusercontent.com",
+				"GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT",
+			},
+			Filesystem: []*FilesystemConfig{
+				{Src: "/nix/store"},
+				{Src: "/run/current-system"},
+				{Src: "/run/opengl-driver"},
+				{Src: "/var/db/nix-channels"},
+				{Src: "/var/lib/fortify/u0/org.chromium.Chromium",
+					Dst: "/data/data/org.chromium.Chromium", Write: true, Must: true},
+				{Src: "/dev/dri", Device: true},
+			},
+			Link:    [][2]string{{"/run/user/65534", "/run/user/150"}},
+			Etc:     "/etc",
+			AutoEtc: true,
+			Cover:   []string{"/var/run/nscd"},
+		},
+	}
+}

fst/template_test.go

@@ -0,0 +1,140 @@
+package fst_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"git.gensokyo.uk/security/fortify/fst"
+)
+
+func TestTemplate(t *testing.T) {
+	const want = `{
+	"id": "org.chromium.Chromium",
+	"path": "/run/current-system/sw/bin/chromium",
+	"args": [
+		"chromium",
+		"--ignore-gpu-blocklist",
+		"--disable-smooth-scrolling",
+		"--enable-features=UseOzonePlatform",
+		"--ozone-platform=wayland"
+	],
+	"enablements": 13,
+	"session_bus": {
+		"see": null,
+		"talk": [
+			"org.freedesktop.Notifications",
+			"org.freedesktop.FileManager1",
+			"org.freedesktop.ScreenSaver",
+			"org.freedesktop.secrets",
+			"org.kde.kwalletd5",
+			"org.kde.kwalletd6",
+			"org.gnome.SessionManager"
+		],
+		"own": [
+			"org.chromium.Chromium.*",
+			"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+			"org.mpris.MediaPlayer2.chromium.*"
+		],
+		"call": {
+			"org.freedesktop.portal.*": "*"
+		},
+		"broadcast": {
+			"org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
+		},
+		"filter": true
+	},
+	"system_bus": {
+		"see": null,
+		"talk": [
+			"org.bluez",
+			"org.freedesktop.Avahi",
+			"org.freedesktop.UPower"
+		],
+		"own": null,
+		"call": null,
+		"broadcast": null,
+		"filter": true
+	},
+	"username": "chronos",
+	"shell": "/run/current-system/sw/bin/zsh",
+	"data": "/var/lib/fortify/u0/org.chromium.Chromium",
+	"dir": "/data/data/org.chromium.Chromium",
+	"extra_perms": [
+		{
+			"ensure": true,
+			"path": "/var/lib/fortify/u0",
+			"x": true
+		},
+		{
+			"path": "/var/lib/fortify/u0/org.chromium.Chromium",
+			"r": true,
+			"w": true,
+			"x": true
+		}
+	],
+	"identity": 9,
+	"groups": [
+		"video",
+		"dialout",
+		"plugdev"
+	],
+	"container": {
+		"hostname": "localhost",
+		"seccomp": 32,
+		"devel": true,
+		"userns": true,
+		"net": true,
+		"tty": true,
+		"multiarch": true,
+		"env": {
+			"GOOGLE_API_KEY": "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
+			"GOOGLE_DEFAULT_CLIENT_ID": "77185425430.apps.googleusercontent.com",
+			"GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT"
+		},
+		"map_real_uid": true,
+		"device": true,
+		"filesystem": [
+			{
+				"src": "/nix/store"
+			},
+			{
+				"src": "/run/current-system"
+			},
+			{
+				"src": "/run/opengl-driver"
+			},
+			{
+				"src": "/var/db/nix-channels"
+			},
+			{
+				"dst": "/data/data/org.chromium.Chromium",
+				"src": "/var/lib/fortify/u0/org.chromium.Chromium",
+				"write": true,
+				"require": true
+			},
+			{
+				"src": "/dev/dri",
+				"dev": true
+			}
+		],
+		"symlink": [
+			[
+				"/run/user/65534",
+				"/run/user/150"
+			]
+		],
+		"etc": "/etc",
+		"auto_etc": true,
+		"cover": [
+			"/var/run/nscd"
+		]
+	}
+}`
+
+	if p, err := json.MarshalIndent(fst.Template(), "", "\t"); err != nil {
+		t.Fatalf("cannot marshal: %v", err)
+	} else if s := string(p); s != want {
+		t.Fatalf("Template:\n%s\nwant:\n%s",
+			s, want)
+	}
+}

helper/args.go

@@ -1,38 +1,17 @@
 package helper
 
 import (
-	"errors"
+	"bytes"
 	"io"
-	"strings"
+	"syscall"
 )
 
-var (
+type argsWt [][]byte
-	ErrContainsNull = errors.New("argument contains null character")
-)
-
-type argsWt []string
-
-// checks whether any element contains the null character
-// must be called before args use and args must not be modified after call
-func (a argsWt) check() error {
-	for _, arg := range a {
-		for _, b := range arg {
-			if b == '\x00' {
-				return ErrContainsNull
-			}
-		}
-	}
-
-	return nil
-}
 
 func (a argsWt) WriteTo(w io.Writer) (int64, error) {
-	// assuming already checked
-
 	nt := 0
-	// write null terminated arguments
 	for _, arg := range a {
-		n, err := w.Write([]byte(arg + "\x00"))
+		n, err := w.Write(arg)
 		nt += n
 
 		if err != nil {
@@ -44,18 +23,32 @@ func (a argsWt) WriteTo(w io.Writer) (int64, error) {
 }
 
 func (a argsWt) String() string {
-	return strings.Join(a, " ")
+	return string(
+		bytes.TrimSuffix(
+			bytes.ReplaceAll(
+				bytes.Join(a, nil),
+				[]byte{0}, []byte{' '},
+			),
+			[]byte{' '},
+		),
+	)
 }
 
-// NewCheckedArgs returns a checked argument writer for args.
+// NewCheckedArgs returns a checked null-terminated argument writer for a copy of args.
-// Callers must not retain any references to args.
+func NewCheckedArgs(args []string) (wt io.WriterTo, err error) {
-func NewCheckedArgs(args []string) (io.WriterTo, error) {
+	a := make(argsWt, len(args))
-	a := argsWt(args)
+	for i, arg := range args {
-	return a, a.check()
+		a[i], err = syscall.ByteSliceFromString(arg)
+		if err != nil {
+			return
+		}
+	}
+	wt = a
+	return
 }
 
-// MustNewCheckedArgs returns a checked argument writer for args and panics if check fails.
+// MustNewCheckedArgs returns a checked null-terminated argument writer for a copy of args.
-// Callers must not retain any references to args.
+// If s contains a NUL byte this function panics instead of returning an error.
 func MustNewCheckedArgs(args []string) io.WriterTo {
 	a, err := NewCheckedArgs(args)
 	if err != nil {

helper/args_test.go

@@ -4,34 +4,33 @@ import (
 	"errors"
 	"fmt"
 	"strings"
+	"syscall"
 	"testing"
 
 	"git.gensokyo.uk/security/fortify/helper"
 )
 
-func Test_argsFd_String(t *testing.T) {
+func TestArgsString(t *testing.T) {
 	wantString := strings.Join(wantArgs, " ")
 	if got := argsWt.(fmt.Stringer).String(); got != wantString {
-		t.Errorf("String(): got %v; want %v",
+		t.Errorf("String: %q, want %q",
 			got, wantString)
 	}
 }
 
 func TestNewCheckedArgs(t *testing.T) {
 	args := []string{"\x00"}
-	if _, err := helper.NewCheckedArgs(args); !errors.Is(err, helper.ErrContainsNull) {
+	if _, err := helper.NewCheckedArgs(args); !errors.Is(err, syscall.EINVAL) {
-		t.Errorf("NewCheckedArgs(%q) error = %v, wantErr %v",
+		t.Errorf("NewCheckedArgs: error = %v, wantErr %v",
-			args,
+			err, syscall.EINVAL)
-			err, helper.ErrContainsNull)
 	}
 
 	t.Run("must panic", func(t *testing.T) {
 		badPayload := []string{"\x00"}
 		defer func() {
-			wantPanic := "argument contains null character"
+			wantPanic := "invalid argument"
 			if r := recover(); r != wantPanic {
-				t.Errorf("MustNewCheckedArgs(%q) panic = %v, wantPanic %v",
+				t.Errorf("MustNewCheckedArgs: panic = %v, wantPanic %v",
-					badPayload,
 					r, wantPanic)
 			}
 		}()

helper/helper_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"os"
 	"strconv"
 	"strings"
 	"testing"
@@ -55,8 +56,8 @@ func testHelper(t *testing.T, createHelper func(ctx context.Context, setOutput f
 
 	t.Run("start helper with status channel and wait", func(t *testing.T) {
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-		stdout, stderr := new(strings.Builder), new(strings.Builder)
+		stdout := new(strings.Builder)
-		h := createHelper(ctx, func(stdoutP, stderrP *io.Writer) { *stdoutP, *stderrP = stdout, stderr }, true)
+		h := createHelper(ctx, func(stdoutP, stderrP *io.Writer) { *stdoutP, *stderrP = stdout, os.Stderr }, true)
 
 		t.Run("wait not yet started helper", func(t *testing.T) {
 			defer func() {
@@ -88,8 +89,8 @@ func testHelper(t *testing.T, createHelper func(ctx context.Context, setOutput f
 
 		t.Log("waiting on helper")
 		if err := h.Wait(); !errors.Is(err, context.Canceled) {
-			t.Errorf("Wait() err = %v stderr = %s",
+			t.Errorf("Wait: error = %v",
-				err, stderr)
+				err)
 		}
 
 		t.Run("wait already finalised helper", func(t *testing.T) {
@@ -101,8 +102,8 @@ func testHelper(t *testing.T, createHelper func(ctx context.Context, setOutput f
 			}
 		})
 
-		if got := stderr.String(); got != wantPayload {
+		if got := trimStdout(stdout); got != wantPayload {
-			t.Errorf("Start: stderr = %v, want %v",
+			t.Errorf("Start: stdout = %q, want %q",
 				got, wantPayload)
 		}
 	})
@@ -110,23 +111,27 @@ func testHelper(t *testing.T, createHelper func(ctx context.Context, setOutput f
 	t.Run("start helper and wait", func(t *testing.T) {
 		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 		defer cancel()
-		stdout, stderr := new(strings.Builder), new(strings.Builder)
+		stdout := new(strings.Builder)
-		h := createHelper(ctx, func(stdoutP, stderrP *io.Writer) { *stdoutP, *stderrP = stdout, stderr }, false)
+		h := createHelper(ctx, func(stdoutP, stderrP *io.Writer) { *stdoutP, *stderrP = stdout, os.Stderr }, false)
 
 		if err := h.Start(); err != nil {
-			t.Errorf("Start() error = %v",
+			t.Errorf("Start: error = %v",
 				err)
 			return
 		}
 
 		if err := h.Wait(); err != nil {
-			t.Errorf("Wait() err = %v stdout = %s stderr = %s",
+			t.Errorf("Wait: error = %v stdout = %q",
-				err, stdout, stderr)
+				err, stdout)
 		}
 
-		if got := stderr.String(); got != wantPayload {
+		if got := trimStdout(stdout); got != wantPayload {
-			t.Errorf("Start() stderr = %v, want %v",
+			t.Errorf("Start: stdout = %q, want %q",
 				got, wantPayload)
 		}
 	})
 }
+
+func trimStdout(stdout fmt.Stringer) string {
+	return strings.TrimPrefix(stdout.String(), "=== RUN   TestHelperInit\n")
+}

helper/stub.go

@@ -63,7 +63,7 @@ func flagRestoreFiles(offset int, ap, sp string) (argsFile, statFile *os.File) {
 func genericStub(argsFile, statFile *os.File) {
 	if argsFile != nil {
 		// this output is checked by parent
-		if _, err := io.Copy(os.Stderr, argsFile); err != nil {
+		if _, err := io.Copy(os.Stdout, argsFile); err != nil {
 			panic("cannot read args: " + err.Error())
 		}
 	}

internal/app/app.go

@@ -1,82 +1,59 @@
+// Package app defines the generic [App] interface.
 package app
 
 import (
-	"context"
+	"syscall"
-	"fmt"
+	"time"
-	"log"
-	"sync"
 
 	"git.gensokyo.uk/security/fortify/fst"
-	"git.gensokyo.uk/security/fortify/internal/fmsg"
-	"git.gensokyo.uk/security/fortify/internal/sys"
 )
 
-func New(ctx context.Context, os sys.State) (fst.App, error) {
+type App interface {
-	a := new(app)
+	// ID returns a copy of [ID] held by App.
-	a.sys = os
+	ID() ID
-	a.ctx = ctx
 
-	id := new(fst.ID)
+	// Seal determines the outcome of config as a [SealedApp].
-	err := fst.NewAppID(id)
+	// The value of config might be overwritten and must not be used again.
-	a.id = newID(id)
+	Seal(config *fst.Config) (SealedApp, error)
 
-	return a, err
+	String() string
 }
 
-func MustNew(ctx context.Context, os sys.State) fst.App {
+type SealedApp interface {
-	a, err := New(ctx, os)
+	// Run commits sealed system setup and starts the app process.
-	if err != nil {
+	Run(rs *RunState) error
-		log.Fatalf("cannot create app: %v", err)
-	}
-	return a
 }
 
-type app struct {
+// RunState stores the outcome of a call to [SealedApp.Run].
-	id  *stringPair[fst.ID]
+type RunState struct {
-	sys sys.State
+	// Time is the exact point in time where the process was created.
-	ctx context.Context
+	// Location must be set to UTC.
+	//
+	// Time is nil if no process was ever created.
+	Time *time.Time
+	// RevertErr is stored by the deferred revert call.
+	RevertErr error
+	// WaitErr is the generic error value created by the standard library.
+	WaitErr error
 
-	*outcome
+	syscall.WaitStatus
-	mu sync.RWMutex
 }
 
-func (a *app) ID() fst.ID { a.mu.RLock(); defer a.mu.RUnlock(); return a.id.unwrap() }
+// SetStart stores the current time in [RunState] once.
-
+func (rs *RunState) SetStart() {
-func (a *app) String() string {
+	if rs.Time != nil {
-	if a == nil {
+		panic("attempted to store time twice")
-		return "(invalid app)"
 	}
-
+	now := time.Now().UTC()
-	a.mu.RLock()
+	rs.Time = &now
-	defer a.mu.RUnlock()
-
-	if a.outcome != nil {
-		if a.outcome.user.uid == nil {
-			return fmt.Sprintf("(sealed app %s with invalid uid)", a.id)
-		}
-		return fmt.Sprintf("(sealed app %s as uid %s)", a.id, a.outcome.user.uid)
-	}
-
-	return fmt.Sprintf("(unsealed app %s)", a.id)
 }
 
-func (a *app) Seal(config *fst.Config) (fst.SealedApp, error) {
+// Paths contains environment-dependent paths used by fortify.
-	a.mu.Lock()
+type Paths struct {
-	defer a.mu.Unlock()
+	// path to shared directory (usually `/tmp/fortify.%d`)
-
+	SharePath string `json:"share_path"`
-	if a.outcome != nil {
+	// XDG_RUNTIME_DIR value (usually `/run/user/%d`)
-		panic("app sealed twice")
+	RuntimePath string `json:"runtime_path"`
-	}
+	// application runtime directory (usually `/run/user/%d/fortify`)
-	if config == nil {
+	RunDirPath string `json:"run_dir_path"`
-		return nil, fmsg.WrapError(ErrConfig,
-			"attempted to seal app with nil config")
-	}
-
-	seal := new(outcome)
-	seal.id = a.id
-	err := seal.finalise(a.ctx, a.sys, config)
-	if err == nil {
-		a.outcome = seal
-	}
-	return seal, err
 }

internal/app/app_nixos_test.go

@@ -1,219 +0,0 @@
-package app_test
-
-import (
-	"git.gensokyo.uk/security/fortify/acl"
-	"git.gensokyo.uk/security/fortify/dbus"
-	"git.gensokyo.uk/security/fortify/fst"
-	"git.gensokyo.uk/security/fortify/sandbox"
-	"git.gensokyo.uk/security/fortify/system"
-)
-
-var testCasesNixos = []sealTestCase{
-	{
-		"nixos chromium direct wayland", new(stubNixOS),
-		&fst.Config{
-			ID:   "org.chromium.Chromium",
-			Path: "/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start",
-			Confinement: fst.ConfinementConfig{
-				AppID: 1, Groups: []string{}, Username: "u0_a1",
-				Outer: "/var/lib/persist/module/fortify/0/1",
-				Sandbox: &fst.SandboxConfig{
-					Userns: true, Net: true, MapRealUID: true, DirectWayland: true, Env: nil, AutoEtc: true,
-					Filesystem: []*fst.FilesystemConfig{
-						{Src: "/bin", Must: true}, {Src: "/usr/bin", Must: true},
-						{Src: "/nix/store", Must: true}, {Src: "/run/current-system", Must: true},
-						{Src: "/sys/block"}, {Src: "/sys/bus"}, {Src: "/sys/class"}, {Src: "/sys/dev"}, {Src: "/sys/devices"},
-						{Src: "/run/opengl-driver", Must: true}, {Src: "/dev/dri", Device: true},
-					},
-					Cover: []string{"/var/run/nscd"},
-				},
-				SystemBus: &dbus.Config{
-					Talk:   []string{"org.bluez", "org.freedesktop.Avahi", "org.freedesktop.UPower"},
-					Filter: true,
-				},
-				SessionBus: &dbus.Config{
-					Talk: []string{
-						"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
-						"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
-						"org.kde.kwalletd5", "org.kde.kwalletd6",
-					},
-					Own: []string{
-						"org.chromium.Chromium.*",
-						"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-						"org.mpris.MediaPlayer2.chromium.*",
-					},
-					Call: map[string]string{}, Broadcast: map[string]string{},
-					Filter: true,
-				},
-				Enablements: system.EWayland | system.EDBus | system.EPulse,
-			},
-		},
-		fst.ID{
-			0x8e, 0x2c, 0x76, 0xb0,
-			0x66, 0xda, 0xbe, 0x57,
-			0x4c, 0xf0, 0x73, 0xbd,
-			0xb4, 0x6e, 0xb5, 0xc1,
-		},
-		system.New(1000001).
-			Ensure("/tmp/fortify.1971", 0711).
-			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
-			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
-			Ephemeral(system.Process, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1", 0711).
-			Ephemeral(system.Process, "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir/1", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/1", acl.Read, acl.Write, acl.Execute).
-			UpdatePermType(system.EWayland, "/run/user/1971/wayland-0", acl.Read, acl.Write, acl.Execute).
-			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/pulse").
-			CopyFile(nil, "/home/ophestra/xdg/config/pulse/cookie", 256, 256).
-			MustProxyDBus("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", &dbus.Config{
-				Talk: []string{
-					"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
-					"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
-					"org.kde.kwalletd5", "org.kde.kwalletd6",
-				},
-				Own: []string{
-					"org.chromium.Chromium.*",
-					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-					"org.mpris.MediaPlayer2.chromium.*",
-				},
-				Call: map[string]string{}, Broadcast: map[string]string{},
-				Filter: true,
-			}, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", &dbus.Config{
-				Talk: []string{
-					"org.bluez",
-					"org.freedesktop.Avahi",
-					"org.freedesktop.UPower",
-				},
-				Filter: true,
-			}).
-			UpdatePerm("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", acl.Read, acl.Write).
-			UpdatePerm("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", acl.Read, acl.Write),
-		&sandbox.Params{
-			Uid:   1971,
-			Gid:   100,
-			Flags: sandbox.FAllowNet | sandbox.FAllowUserns,
-			Dir:   "/var/lib/persist/module/fortify/0/1",
-			Path:  "/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start",
-			Args:  []string{"/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start"},
-			Env: []string{
-				"DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1971/bus",
-				"DBUS_SYSTEM_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket",
-				"HOME=/var/lib/persist/module/fortify/0/1",
-				"PULSE_COOKIE=" + fst.Tmp + "/pulse-cookie",
-				"PULSE_SERVER=unix:/run/user/1971/pulse/native",
-				"TERM=xterm-256color",
-				"USER=u0_a1",
-				"WAYLAND_DISPLAY=wayland-0",
-				"XDG_RUNTIME_DIR=/run/user/1971",
-				"XDG_SESSION_CLASS=user",
-				"XDG_SESSION_TYPE=tty",
-			},
-			Ops: new(sandbox.Ops).
-				Proc("/proc").
-				Tmpfs(fst.Tmp, 4096, 0755).
-				Dev("/dev").Mqueue("/dev/mqueue").
-				Bind("/bin", "/bin", 0).
-				Bind("/usr/bin", "/usr/bin", 0).
-				Bind("/nix/store", "/nix/store", 0).
-				Bind("/run/current-system", "/run/current-system", 0).
-				Bind("/sys/block", "/sys/block", sandbox.BindOptional).
-				Bind("/sys/bus", "/sys/bus", sandbox.BindOptional).
-				Bind("/sys/class", "/sys/class", sandbox.BindOptional).
-				Bind("/sys/dev", "/sys/dev", sandbox.BindOptional).
-				Bind("/sys/devices", "/sys/devices", sandbox.BindOptional).
-				Bind("/run/opengl-driver", "/run/opengl-driver", 0).
-				Bind("/dev/dri", "/dev/dri", sandbox.BindDevice|sandbox.BindWritable|sandbox.BindOptional).
-				Bind("/etc", fst.Tmp+"/etc", 0).
-				Link(fst.Tmp+"/etc/alsa", "/etc/alsa").
-				Link(fst.Tmp+"/etc/bashrc", "/etc/bashrc").
-				Link(fst.Tmp+"/etc/binfmt.d", "/etc/binfmt.d").
-				Link(fst.Tmp+"/etc/dbus-1", "/etc/dbus-1").
-				Link(fst.Tmp+"/etc/default", "/etc/default").
-				Link(fst.Tmp+"/etc/ethertypes", "/etc/ethertypes").
-				Link(fst.Tmp+"/etc/fonts", "/etc/fonts").
-				Link(fst.Tmp+"/etc/fstab", "/etc/fstab").
-				Link(fst.Tmp+"/etc/fuse.conf", "/etc/fuse.conf").
-				Link(fst.Tmp+"/etc/host.conf", "/etc/host.conf").
-				Link(fst.Tmp+"/etc/hostid", "/etc/hostid").
-				Link(fst.Tmp+"/etc/hostname", "/etc/hostname").
-				Link(fst.Tmp+"/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
-				Link(fst.Tmp+"/etc/hosts", "/etc/hosts").
-				Link(fst.Tmp+"/etc/inputrc", "/etc/inputrc").
-				Link(fst.Tmp+"/etc/ipsec.d", "/etc/ipsec.d").
-				Link(fst.Tmp+"/etc/issue", "/etc/issue").
-				Link(fst.Tmp+"/etc/kbd", "/etc/kbd").
-				Link(fst.Tmp+"/etc/libblockdev", "/etc/libblockdev").
-				Link(fst.Tmp+"/etc/locale.conf", "/etc/locale.conf").
-				Link(fst.Tmp+"/etc/localtime", "/etc/localtime").
-				Link(fst.Tmp+"/etc/login.defs", "/etc/login.defs").
-				Link(fst.Tmp+"/etc/lsb-release", "/etc/lsb-release").
-				Link(fst.Tmp+"/etc/lvm", "/etc/lvm").
-				Link(fst.Tmp+"/etc/machine-id", "/etc/machine-id").
-				Link(fst.Tmp+"/etc/man_db.conf", "/etc/man_db.conf").
-				Link(fst.Tmp+"/etc/modprobe.d", "/etc/modprobe.d").
-				Link(fst.Tmp+"/etc/modules-load.d", "/etc/modules-load.d").
-				Link("/proc/mounts", "/etc/mtab").
-				Link(fst.Tmp+"/etc/nanorc", "/etc/nanorc").
-				Link(fst.Tmp+"/etc/netgroup", "/etc/netgroup").
-				Link(fst.Tmp+"/etc/NetworkManager", "/etc/NetworkManager").
-				Link(fst.Tmp+"/etc/nix", "/etc/nix").
-				Link(fst.Tmp+"/etc/nixos", "/etc/nixos").
-				Link(fst.Tmp+"/etc/NIXOS", "/etc/NIXOS").
-				Link(fst.Tmp+"/etc/nscd.conf", "/etc/nscd.conf").
-				Link(fst.Tmp+"/etc/nsswitch.conf", "/etc/nsswitch.conf").
-				Link(fst.Tmp+"/etc/opensnitchd", "/etc/opensnitchd").
-				Link(fst.Tmp+"/etc/os-release", "/etc/os-release").
-				Link(fst.Tmp+"/etc/pam", "/etc/pam").
-				Link(fst.Tmp+"/etc/pam.d", "/etc/pam.d").
-				Link(fst.Tmp+"/etc/pipewire", "/etc/pipewire").
-				Link(fst.Tmp+"/etc/pki", "/etc/pki").
-				Link(fst.Tmp+"/etc/polkit-1", "/etc/polkit-1").
-				Link(fst.Tmp+"/etc/profile", "/etc/profile").
-				Link(fst.Tmp+"/etc/protocols", "/etc/protocols").
-				Link(fst.Tmp+"/etc/qemu", "/etc/qemu").
-				Link(fst.Tmp+"/etc/resolv.conf", "/etc/resolv.conf").
-				Link(fst.Tmp+"/etc/resolvconf.conf", "/etc/resolvconf.conf").
-				Link(fst.Tmp+"/etc/rpc", "/etc/rpc").
-				Link(fst.Tmp+"/etc/samba", "/etc/samba").
-				Link(fst.Tmp+"/etc/sddm.conf", "/etc/sddm.conf").
-				Link(fst.Tmp+"/etc/secureboot", "/etc/secureboot").
-				Link(fst.Tmp+"/etc/services", "/etc/services").
-				Link(fst.Tmp+"/etc/set-environment", "/etc/set-environment").
-				Link(fst.Tmp+"/etc/shadow", "/etc/shadow").
-				Link(fst.Tmp+"/etc/shells", "/etc/shells").
-				Link(fst.Tmp+"/etc/ssh", "/etc/ssh").
-				Link(fst.Tmp+"/etc/ssl", "/etc/ssl").
-				Link(fst.Tmp+"/etc/static", "/etc/static").
-				Link(fst.Tmp+"/etc/subgid", "/etc/subgid").
-				Link(fst.Tmp+"/etc/subuid", "/etc/subuid").
-				Link(fst.Tmp+"/etc/sudoers", "/etc/sudoers").
-				Link(fst.Tmp+"/etc/sysctl.d", "/etc/sysctl.d").
-				Link(fst.Tmp+"/etc/systemd", "/etc/systemd").
-				Link(fst.Tmp+"/etc/terminfo", "/etc/terminfo").
-				Link(fst.Tmp+"/etc/tmpfiles.d", "/etc/tmpfiles.d").
-				Link(fst.Tmp+"/etc/udev", "/etc/udev").
-				Link(fst.Tmp+"/etc/udisks2", "/etc/udisks2").
-				Link(fst.Tmp+"/etc/UPower", "/etc/UPower").
-				Link(fst.Tmp+"/etc/vconsole.conf", "/etc/vconsole.conf").
-				Link(fst.Tmp+"/etc/X11", "/etc/X11").
-				Link(fst.Tmp+"/etc/zfs", "/etc/zfs").
-				Link(fst.Tmp+"/etc/zinputrc", "/etc/zinputrc").
-				Link(fst.Tmp+"/etc/zoneinfo", "/etc/zoneinfo").
-				Link(fst.Tmp+"/etc/zprofile", "/etc/zprofile").
-				Link(fst.Tmp+"/etc/zshenv", "/etc/zshenv").
-				Link(fst.Tmp+"/etc/zshrc", "/etc/zshrc").
-				Tmpfs("/run/user", 4096, 0755).
-				Tmpfs("/run/user/1971", 8388608, 0755).
-				Bind("/tmp/fortify.1971/tmpdir/1", "/tmp", sandbox.BindWritable).
-				Bind("/var/lib/persist/module/fortify/0/1", "/var/lib/persist/module/fortify/0/1", sandbox.BindWritable).
-				Place("/etc/passwd", []byte("u0_a1:x:1971:100:Fortify:/var/lib/persist/module/fortify/0/1:/run/current-system/sw/bin/zsh\n")).
-				Place("/etc/group", []byte("fortify:x:100:\n")).
-				Bind("/run/user/1971/wayland-0", "/run/user/1971/wayland-0", 0).
-				Bind("/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/pulse", "/run/user/1971/pulse/native", 0).
-				Place(fst.Tmp+"/pulse-cookie", nil).
-				Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", "/run/user/1971/bus", 0).
-				Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", "/run/dbus/system_bus_socket", 0).
-				Tmpfs("/var/run/nscd", 8192, 0755),
-		},
-	},
-}

internal/app/app_pd_test.go

@@ -1,382 +0,0 @@
-package app_test
-
-import (
-	"os"
-
-	"git.gensokyo.uk/security/fortify/acl"
-	"git.gensokyo.uk/security/fortify/dbus"
-	"git.gensokyo.uk/security/fortify/fst"
-	"git.gensokyo.uk/security/fortify/sandbox"
-	"git.gensokyo.uk/security/fortify/system"
-)
-
-var testCasesPd = []sealTestCase{
-	{
-		"nixos permissive defaults no enablements", new(stubNixOS),
-		&fst.Config{
-			Confinement: fst.ConfinementConfig{
-				AppID:    0,
-				Username: "chronos",
-				Outer:    "/home/chronos",
-			},
-		},
-		fst.ID{
-			0x4a, 0x45, 0x0b, 0x65,
-			0x96, 0xd7, 0xbc, 0x15,
-			0xbd, 0x01, 0x78, 0x0e,
-			0xb9, 0xa6, 0x07, 0xac,
-		},
-		system.New(1000000).
-			Ensure("/tmp/fortify.1971", 0711).
-			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
-			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
-			Ephemeral(system.Process, "/tmp/fortify.1971/4a450b6596d7bc15bd01780eb9a607ac", 0711).
-			Ephemeral(system.Process, "/run/user/1971/fortify/4a450b6596d7bc15bd01780eb9a607ac", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/4a450b6596d7bc15bd01780eb9a607ac", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir/0", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/0", acl.Read, acl.Write, acl.Execute),
-		&sandbox.Params{
-			Flags: sandbox.FAllowNet | sandbox.FAllowUserns | sandbox.FAllowTTY,
-			Dir:   "/home/chronos",
-			Path:  "/run/current-system/sw/bin/zsh",
-			Args:  []string{"/run/current-system/sw/bin/zsh"},
-			Env: []string{
-				"HOME=/home/chronos",
-				"TERM=xterm-256color",
-				"USER=chronos",
-				"XDG_RUNTIME_DIR=/run/user/65534",
-				"XDG_SESSION_CLASS=user",
-				"XDG_SESSION_TYPE=tty",
-			},
-			Ops: new(sandbox.Ops).
-				Proc("/proc").
-				Tmpfs(fst.Tmp, 4096, 0755).
-				Dev("/dev").Mqueue("/dev/mqueue").
-				Bind("/bin", "/bin", sandbox.BindWritable).
-				Bind("/boot", "/boot", sandbox.BindWritable).
-				Bind("/home", "/home", sandbox.BindWritable).
-				Bind("/lib", "/lib", sandbox.BindWritable).
-				Bind("/lib64", "/lib64", sandbox.BindWritable).
-				Bind("/nix", "/nix", sandbox.BindWritable).
-				Bind("/root", "/root", sandbox.BindWritable).
-				Bind("/run", "/run", sandbox.BindWritable).
-				Bind("/srv", "/srv", sandbox.BindWritable).
-				Bind("/sys", "/sys", sandbox.BindWritable).
-				Bind("/usr", "/usr", sandbox.BindWritable).
-				Bind("/var", "/var", sandbox.BindWritable).
-				Bind("/dev/kvm", "/dev/kvm", sandbox.BindWritable|sandbox.BindDevice|sandbox.BindOptional).
-				Tmpfs("/run/user/1971", 8192, 0755).
-				Tmpfs("/run/dbus", 8192, 0755).
-				Bind("/etc", fst.Tmp+"/etc", 0).
-				Link(fst.Tmp+"/etc/alsa", "/etc/alsa").
-				Link(fst.Tmp+"/etc/bashrc", "/etc/bashrc").
-				Link(fst.Tmp+"/etc/binfmt.d", "/etc/binfmt.d").
-				Link(fst.Tmp+"/etc/dbus-1", "/etc/dbus-1").
-				Link(fst.Tmp+"/etc/default", "/etc/default").
-				Link(fst.Tmp+"/etc/ethertypes", "/etc/ethertypes").
-				Link(fst.Tmp+"/etc/fonts", "/etc/fonts").
-				Link(fst.Tmp+"/etc/fstab", "/etc/fstab").
-				Link(fst.Tmp+"/etc/fuse.conf", "/etc/fuse.conf").
-				Link(fst.Tmp+"/etc/host.conf", "/etc/host.conf").
-				Link(fst.Tmp+"/etc/hostid", "/etc/hostid").
-				Link(fst.Tmp+"/etc/hostname", "/etc/hostname").
-				Link(fst.Tmp+"/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
-				Link(fst.Tmp+"/etc/hosts", "/etc/hosts").
-				Link(fst.Tmp+"/etc/inputrc", "/etc/inputrc").
-				Link(fst.Tmp+"/etc/ipsec.d", "/etc/ipsec.d").
-				Link(fst.Tmp+"/etc/issue", "/etc/issue").
-				Link(fst.Tmp+"/etc/kbd", "/etc/kbd").
-				Link(fst.Tmp+"/etc/libblockdev", "/etc/libblockdev").
-				Link(fst.Tmp+"/etc/locale.conf", "/etc/locale.conf").
-				Link(fst.Tmp+"/etc/localtime", "/etc/localtime").
-				Link(fst.Tmp+"/etc/login.defs", "/etc/login.defs").
-				Link(fst.Tmp+"/etc/lsb-release", "/etc/lsb-release").
-				Link(fst.Tmp+"/etc/lvm", "/etc/lvm").
-				Link(fst.Tmp+"/etc/machine-id", "/etc/machine-id").
-				Link(fst.Tmp+"/etc/man_db.conf", "/etc/man_db.conf").
-				Link(fst.Tmp+"/etc/modprobe.d", "/etc/modprobe.d").
-				Link(fst.Tmp+"/etc/modules-load.d", "/etc/modules-load.d").
-				Link("/proc/mounts", "/etc/mtab").
-				Link(fst.Tmp+"/etc/nanorc", "/etc/nanorc").
-				Link(fst.Tmp+"/etc/netgroup", "/etc/netgroup").
-				Link(fst.Tmp+"/etc/NetworkManager", "/etc/NetworkManager").
-				Link(fst.Tmp+"/etc/nix", "/etc/nix").
-				Link(fst.Tmp+"/etc/nixos", "/etc/nixos").
-				Link(fst.Tmp+"/etc/NIXOS", "/etc/NIXOS").
-				Link(fst.Tmp+"/etc/nscd.conf", "/etc/nscd.conf").
-				Link(fst.Tmp+"/etc/nsswitch.conf", "/etc/nsswitch.conf").
-				Link(fst.Tmp+"/etc/opensnitchd", "/etc/opensnitchd").
-				Link(fst.Tmp+"/etc/os-release", "/etc/os-release").
-				Link(fst.Tmp+"/etc/pam", "/etc/pam").
-				Link(fst.Tmp+"/etc/pam.d", "/etc/pam.d").
-				Link(fst.Tmp+"/etc/pipewire", "/etc/pipewire").
-				Link(fst.Tmp+"/etc/pki", "/etc/pki").
-				Link(fst.Tmp+"/etc/polkit-1", "/etc/polkit-1").
-				Link(fst.Tmp+"/etc/profile", "/etc/profile").
-				Link(fst.Tmp+"/etc/protocols", "/etc/protocols").
-				Link(fst.Tmp+"/etc/qemu", "/etc/qemu").
-				Link(fst.Tmp+"/etc/resolv.conf", "/etc/resolv.conf").
-				Link(fst.Tmp+"/etc/resolvconf.conf", "/etc/resolvconf.conf").
-				Link(fst.Tmp+"/etc/rpc", "/etc/rpc").
-				Link(fst.Tmp+"/etc/samba", "/etc/samba").
-				Link(fst.Tmp+"/etc/sddm.conf", "/etc/sddm.conf").
-				Link(fst.Tmp+"/etc/secureboot", "/etc/secureboot").
-				Link(fst.Tmp+"/etc/services", "/etc/services").
-				Link(fst.Tmp+"/etc/set-environment", "/etc/set-environment").
-				Link(fst.Tmp+"/etc/shadow", "/etc/shadow").
-				Link(fst.Tmp+"/etc/shells", "/etc/shells").
-				Link(fst.Tmp+"/etc/ssh", "/etc/ssh").
-				Link(fst.Tmp+"/etc/ssl", "/etc/ssl").
-				Link(fst.Tmp+"/etc/static", "/etc/static").
-				Link(fst.Tmp+"/etc/subgid", "/etc/subgid").
-				Link(fst.Tmp+"/etc/subuid", "/etc/subuid").
-				Link(fst.Tmp+"/etc/sudoers", "/etc/sudoers").
-				Link(fst.Tmp+"/etc/sysctl.d", "/etc/sysctl.d").
-				Link(fst.Tmp+"/etc/systemd", "/etc/systemd").
-				Link(fst.Tmp+"/etc/terminfo", "/etc/terminfo").
-				Link(fst.Tmp+"/etc/tmpfiles.d", "/etc/tmpfiles.d").
-				Link(fst.Tmp+"/etc/udev", "/etc/udev").
-				Link(fst.Tmp+"/etc/udisks2", "/etc/udisks2").
-				Link(fst.Tmp+"/etc/UPower", "/etc/UPower").
-				Link(fst.Tmp+"/etc/vconsole.conf", "/etc/vconsole.conf").
-				Link(fst.Tmp+"/etc/X11", "/etc/X11").
-				Link(fst.Tmp+"/etc/zfs", "/etc/zfs").
-				Link(fst.Tmp+"/etc/zinputrc", "/etc/zinputrc").
-				Link(fst.Tmp+"/etc/zoneinfo", "/etc/zoneinfo").
-				Link(fst.Tmp+"/etc/zprofile", "/etc/zprofile").
-				Link(fst.Tmp+"/etc/zshenv", "/etc/zshenv").
-				Link(fst.Tmp+"/etc/zshrc", "/etc/zshrc").
-				Tmpfs("/run/user", 4096, 0755).
-				Tmpfs("/run/user/65534", 8388608, 0755).
-				Bind("/tmp/fortify.1971/tmpdir/0", "/tmp", sandbox.BindWritable).
-				Bind("/home/chronos", "/home/chronos", sandbox.BindWritable).
-				Place("/etc/passwd", []byte("chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n")).
-				Place("/etc/group", []byte("fortify:x:65534:\n")).
-				Tmpfs("/var/run/nscd", 8192, 0755),
-		},
-	},
-	{
-		"nixos permissive defaults chromium", new(stubNixOS),
-		&fst.Config{
-			ID:   "org.chromium.Chromium",
-			Args: []string{"zsh", "-c", "exec chromium "},
-			Confinement: fst.ConfinementConfig{
-				AppID:    9,
-				Groups:   []string{"video"},
-				Username: "chronos",
-				Outer:    "/home/chronos",
-				SessionBus: &dbus.Config{
-					Talk: []string{
-						"org.freedesktop.Notifications",
-						"org.freedesktop.FileManager1",
-						"org.freedesktop.ScreenSaver",
-						"org.freedesktop.secrets",
-						"org.kde.kwalletd5",
-						"org.kde.kwalletd6",
-						"org.gnome.SessionManager",
-					},
-					Own: []string{
-						"org.chromium.Chromium.*",
-						"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-						"org.mpris.MediaPlayer2.chromium.*",
-					},
-					Call: map[string]string{
-						"org.freedesktop.portal.*": "*",
-					},
-					Broadcast: map[string]string{
-						"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
-					},
-					Filter: true,
-				},
-				SystemBus: &dbus.Config{
-					Talk: []string{
-						"org.bluez",
-						"org.freedesktop.Avahi",
-						"org.freedesktop.UPower",
-					},
-					Filter: true,
-				},
-				Enablements: system.EWayland | system.EDBus | system.EPulse,
-			},
-		},
-		fst.ID{
-			0xeb, 0xf0, 0x83, 0xd1,
-			0xb1, 0x75, 0x91, 0x17,
-			0x82, 0xd4, 0x13, 0x36,
-			0x9b, 0x64, 0xce, 0x7c,
-		},
-		system.New(1000009).
-			Ensure("/tmp/fortify.1971", 0711).
-			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
-			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
-			Ephemeral(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c", 0711).
-			Ephemeral(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
-			Ensure("/tmp/fortify.1971/tmpdir/9", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/9", acl.Read, acl.Write, acl.Execute).
-			Ensure("/tmp/fortify.1971/wayland", 0711).
-			Wayland(new(*os.File), "/tmp/fortify.1971/wayland/ebf083d1b175911782d413369b64ce7c", "/run/user/1971/wayland-0", "org.chromium.Chromium", "ebf083d1b175911782d413369b64ce7c").
-			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse").
-			CopyFile(new([]byte), "/home/ophestra/xdg/config/pulse/cookie", 256, 256).
-			MustProxyDBus("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", &dbus.Config{
-				Talk: []string{
-					"org.freedesktop.Notifications",
-					"org.freedesktop.FileManager1",
-					"org.freedesktop.ScreenSaver",
-					"org.freedesktop.secrets",
-					"org.kde.kwalletd5",
-					"org.kde.kwalletd6",
-					"org.gnome.SessionManager",
-				},
-				Own: []string{
-					"org.chromium.Chromium.*",
-					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-					"org.mpris.MediaPlayer2.chromium.*",
-				},
-				Call: map[string]string{
-					"org.freedesktop.portal.*": "*",
-				},
-				Broadcast: map[string]string{
-					"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
-				},
-				Filter: true,
-			}, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", &dbus.Config{
-				Talk: []string{
-					"org.bluez",
-					"org.freedesktop.Avahi",
-					"org.freedesktop.UPower",
-				},
-				Filter: true,
-			}).
-			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", acl.Read, acl.Write).
-			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", acl.Read, acl.Write),
-		&sandbox.Params{
-			Flags: sandbox.FAllowNet | sandbox.FAllowUserns | sandbox.FAllowTTY,
-			Dir:   "/home/chronos",
-			Path:  "/run/current-system/sw/bin/zsh",
-			Args:  []string{"zsh", "-c", "exec chromium "},
-			Env: []string{
-				"DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/65534/bus",
-				"DBUS_SYSTEM_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket",
-				"HOME=/home/chronos",
-				"PULSE_COOKIE=" + fst.Tmp + "/pulse-cookie",
-				"PULSE_SERVER=unix:/run/user/65534/pulse/native",
-				"TERM=xterm-256color",
-				"USER=chronos",
-				"WAYLAND_DISPLAY=wayland-0",
-				"XDG_RUNTIME_DIR=/run/user/65534",
-				"XDG_SESSION_CLASS=user",
-				"XDG_SESSION_TYPE=tty",
-			},
-			Ops: new(sandbox.Ops).
-				Proc("/proc").
-				Tmpfs(fst.Tmp, 4096, 0755).
-				Dev("/dev").Mqueue("/dev/mqueue").
-				Bind("/bin", "/bin", sandbox.BindWritable).
-				Bind("/boot", "/boot", sandbox.BindWritable).
-				Bind("/home", "/home", sandbox.BindWritable).
-				Bind("/lib", "/lib", sandbox.BindWritable).
-				Bind("/lib64", "/lib64", sandbox.BindWritable).
-				Bind("/nix", "/nix", sandbox.BindWritable).
-				Bind("/root", "/root", sandbox.BindWritable).
-				Bind("/run", "/run", sandbox.BindWritable).
-				Bind("/srv", "/srv", sandbox.BindWritable).
-				Bind("/sys", "/sys", sandbox.BindWritable).
-				Bind("/usr", "/usr", sandbox.BindWritable).
-				Bind("/var", "/var", sandbox.BindWritable).
-				Bind("/dev/dri", "/dev/dri", sandbox.BindWritable|sandbox.BindDevice|sandbox.BindOptional).
-				Bind("/dev/kvm", "/dev/kvm", sandbox.BindWritable|sandbox.BindDevice|sandbox.BindOptional).
-				Tmpfs("/run/user/1971", 8192, 0755).
-				Tmpfs("/run/dbus", 8192, 0755).
-				Bind("/etc", fst.Tmp+"/etc", 0).
-				Link(fst.Tmp+"/etc/alsa", "/etc/alsa").
-				Link(fst.Tmp+"/etc/bashrc", "/etc/bashrc").
-				Link(fst.Tmp+"/etc/binfmt.d", "/etc/binfmt.d").
-				Link(fst.Tmp+"/etc/dbus-1", "/etc/dbus-1").
-				Link(fst.Tmp+"/etc/default", "/etc/default").
-				Link(fst.Tmp+"/etc/ethertypes", "/etc/ethertypes").
-				Link(fst.Tmp+"/etc/fonts", "/etc/fonts").
-				Link(fst.Tmp+"/etc/fstab", "/etc/fstab").
-				Link(fst.Tmp+"/etc/fuse.conf", "/etc/fuse.conf").
-				Link(fst.Tmp+"/etc/host.conf", "/etc/host.conf").
-				Link(fst.Tmp+"/etc/hostid", "/etc/hostid").
-				Link(fst.Tmp+"/etc/hostname", "/etc/hostname").
-				Link(fst.Tmp+"/etc/hostname.CHECKSUM", "/etc/hostname.CHECKSUM").
-				Link(fst.Tmp+"/etc/hosts", "/etc/hosts").
-				Link(fst.Tmp+"/etc/inputrc", "/etc/inputrc").
-				Link(fst.Tmp+"/etc/ipsec.d", "/etc/ipsec.d").
-				Link(fst.Tmp+"/etc/issue", "/etc/issue").
-				Link(fst.Tmp+"/etc/kbd", "/etc/kbd").
-				Link(fst.Tmp+"/etc/libblockdev", "/etc/libblockdev").
-				Link(fst.Tmp+"/etc/locale.conf", "/etc/locale.conf").
-				Link(fst.Tmp+"/etc/localtime", "/etc/localtime").
-				Link(fst.Tmp+"/etc/login.defs", "/etc/login.defs").
-				Link(fst.Tmp+"/etc/lsb-release", "/etc/lsb-release").
-				Link(fst.Tmp+"/etc/lvm", "/etc/lvm").
-				Link(fst.Tmp+"/etc/machine-id", "/etc/machine-id").
-				Link(fst.Tmp+"/etc/man_db.conf", "/etc/man_db.conf").
-				Link(fst.Tmp+"/etc/modprobe.d", "/etc/modprobe.d").
-				Link(fst.Tmp+"/etc/modules-load.d", "/etc/modules-load.d").
-				Link("/proc/mounts", "/etc/mtab").
-				Link(fst.Tmp+"/etc/nanorc", "/etc/nanorc").
-				Link(fst.Tmp+"/etc/netgroup", "/etc/netgroup").
-				Link(fst.Tmp+"/etc/NetworkManager", "/etc/NetworkManager").
-				Link(fst.Tmp+"/etc/nix", "/etc/nix").
-				Link(fst.Tmp+"/etc/nixos", "/etc/nixos").
-				Link(fst.Tmp+"/etc/NIXOS", "/etc/NIXOS").
-				Link(fst.Tmp+"/etc/nscd.conf", "/etc/nscd.conf").
-				Link(fst.Tmp+"/etc/nsswitch.conf", "/etc/nsswitch.conf").
-				Link(fst.Tmp+"/etc/opensnitchd", "/etc/opensnitchd").
-				Link(fst.Tmp+"/etc/os-release", "/etc/os-release").
-				Link(fst.Tmp+"/etc/pam", "/etc/pam").
-				Link(fst.Tmp+"/etc/pam.d", "/etc/pam.d").
-				Link(fst.Tmp+"/etc/pipewire", "/etc/pipewire").
-				Link(fst.Tmp+"/etc/pki", "/etc/pki").
-				Link(fst.Tmp+"/etc/polkit-1", "/etc/polkit-1").
-				Link(fst.Tmp+"/etc/profile", "/etc/profile").
-				Link(fst.Tmp+"/etc/protocols", "/etc/protocols").
-				Link(fst.Tmp+"/etc/qemu", "/etc/qemu").
-				Link(fst.Tmp+"/etc/resolv.conf", "/etc/resolv.conf").
-				Link(fst.Tmp+"/etc/resolvconf.conf", "/etc/resolvconf.conf").
-				Link(fst.Tmp+"/etc/rpc", "/etc/rpc").
-				Link(fst.Tmp+"/etc/samba", "/etc/samba").
-				Link(fst.Tmp+"/etc/sddm.conf", "/etc/sddm.conf").
-				Link(fst.Tmp+"/etc/secureboot", "/etc/secureboot").
-				Link(fst.Tmp+"/etc/services", "/etc/services").
-				Link(fst.Tmp+"/etc/set-environment", "/etc/set-environment").
-				Link(fst.Tmp+"/etc/shadow", "/etc/shadow").
-				Link(fst.Tmp+"/etc/shells", "/etc/shells").
-				Link(fst.Tmp+"/etc/ssh", "/etc/ssh").
-				Link(fst.Tmp+"/etc/ssl", "/etc/ssl").
-				Link(fst.Tmp+"/etc/static", "/etc/static").
-				Link(fst.Tmp+"/etc/subgid", "/etc/subgid").
-				Link(fst.Tmp+"/etc/subuid", "/etc/subuid").
-				Link(fst.Tmp+"/etc/sudoers", "/etc/sudoers").
-				Link(fst.Tmp+"/etc/sysctl.d", "/etc/sysctl.d").
-				Link(fst.Tmp+"/etc/systemd", "/etc/systemd").
-				Link(fst.Tmp+"/etc/terminfo", "/etc/terminfo").
-				Link(fst.Tmp+"/etc/tmpfiles.d", "/etc/tmpfiles.d").
-				Link(fst.Tmp+"/etc/udev", "/etc/udev").
-				Link(fst.Tmp+"/etc/udisks2", "/etc/udisks2").
-				Link(fst.Tmp+"/etc/UPower", "/etc/UPower").
-				Link(fst.Tmp+"/etc/vconsole.conf", "/etc/vconsole.conf").
-				Link(fst.Tmp+"/etc/X11", "/etc/X11").
-				Link(fst.Tmp+"/etc/zfs", "/etc/zfs").
-				Link(fst.Tmp+"/etc/zinputrc", "/etc/zinputrc").
-				Link(fst.Tmp+"/etc/zoneinfo", "/etc/zoneinfo").
-				Link(fst.Tmp+"/etc/zprofile", "/etc/zprofile").
-				Link(fst.Tmp+"/etc/zshenv", "/etc/zshenv").
-				Link(fst.Tmp+"/etc/zshrc", "/etc/zshrc").
-				Tmpfs("/run/user", 4096, 0755).
-				Tmpfs("/run/user/65534", 8388608, 0755).
-				Bind("/tmp/fortify.1971/tmpdir/9", "/tmp", sandbox.BindWritable).
-				Bind("/home/chronos", "/home/chronos", sandbox.BindWritable).
-				Place("/etc/passwd", []byte("chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n")).
-				Place("/etc/group", []byte("fortify:x:65534:\n")).
-				Bind("/tmp/fortify.1971/wayland/ebf083d1b175911782d413369b64ce7c", "/run/user/65534/wayland-0", 0).
-				Bind("/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse", "/run/user/65534/pulse/native", 0).
-				Place(fst.Tmp+"/pulse-cookie", nil).
-				Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", "/run/user/65534/bus", 0).
-				Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", "/run/dbus/system_bus_socket", 0).
-				Tmpfs("/var/run/nscd", 8192, 0755),
-		},
-	},
-}

internal/app/id.go

@@ -1,4 +1,4 @@
-package fst
+package app
 
 import (
 	"crypto/rand"

internal/app/id_test.go

@@ -1,22 +1,22 @@
-package fst_test
+package app_test
 
 import (
 	"errors"
 	"testing"
 
-	"git.gensokyo.uk/security/fortify/fst"
+	. "git.gensokyo.uk/security/fortify/internal/app"
 )
 
 func TestParseAppID(t *testing.T) {
 	t.Run("bad length", func(t *testing.T) {
-		if err := fst.ParseAppID(new(fst.ID), "meow"); !errors.Is(err, fst.ErrInvalidLength) {
+		if err := ParseAppID(new(ID), "meow"); !errors.Is(err, ErrInvalidLength) {
-			t.Errorf("ParseAppID: error = %v, wantErr =  %v", err, fst.ErrInvalidLength)
+			t.Errorf("ParseAppID: error = %v, wantErr =  %v", err, ErrInvalidLength)
 		}
 	})
 
 	t.Run("bad byte", func(t *testing.T) {
 		wantErr := "invalid char '\\n' at byte 15"
-		if err := fst.ParseAppID(new(fst.ID), "02bc7f8936b2af6\n\ne2535cd71ef0bb7"); err == nil || err.Error() != wantErr {
+		if err := ParseAppID(new(ID), "02bc7f8936b2af6\n\ne2535cd71ef0bb7"); err == nil || err.Error() != wantErr {
 			t.Errorf("ParseAppID: error = %v, wantErr =  %v", err, wantErr)
 		}
 	})
@@ -30,30 +30,30 @@ func TestParseAppID(t *testing.T) {
 
 func FuzzParseAppID(f *testing.F) {
 	for i := 0; i < 16; i++ {
-		id := new(fst.ID)
+		id := new(ID)
-		if err := fst.NewAppID(id); err != nil {
+		if err := NewAppID(id); err != nil {
 			panic(err.Error())
 		}
 		f.Add(id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7], id[8], id[9], id[10], id[11], id[12], id[13], id[14], id[15])
 	}
 
 	f.Fuzz(func(t *testing.T, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15 byte) {
-		testParseAppID(t, &fst.ID{b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15})
+		testParseAppID(t, &ID{b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15})
 	})
 }
 
 func testParseAppIDWithRandom(t *testing.T) {
-	id := new(fst.ID)
+	id := new(ID)
-	if err := fst.NewAppID(id); err != nil {
+	if err := NewAppID(id); err != nil {
 		t.Fatalf("cannot generate app ID: %v", err)
 	}
 	testParseAppID(t, id)
 }
 
-func testParseAppID(t *testing.T, id *fst.ID) {
+func testParseAppID(t *testing.T, id *ID) {
 	s := id.String()
-	got := new(fst.ID)
+	got := new(ID)
-	if err := fst.ParseAppID(got, s); err != nil {
+	if err := ParseAppID(got, s); err != nil {
 		t.Fatalf("cannot parse app ID: %v", err)
 	}
 

internal/app/instance/common/container.go

@@ -0,0 +1,189 @@
+package common
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"maps"
+	"path"
+	"syscall"
+
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/sys"
+	"git.gensokyo.uk/security/fortify/sandbox"
+	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
+)
+
+// in practice there should be less than 30 entries added by the runtime;
+// allocating slightly more as a margin for future expansion
+const preallocateOpsCount = 1 << 5
+
+// NewContainer initialises [sandbox.Params] via [fst.ContainerConfig].
+// Note that remaining container setup must be queued by the caller.
+func NewContainer(s *fst.ContainerConfig, os sys.State, uid, gid *int) (*sandbox.Params, map[string]string, error) {
+	if s == nil {
+		return nil, nil, syscall.EBADE
+	}
+
+	container := &sandbox.Params{
+		Hostname: s.Hostname,
+		Seccomp:  s.Seccomp,
+	}
+
+	{
+		ops := make(sandbox.Ops, 0, preallocateOpsCount+len(s.Filesystem)+len(s.Link)+len(s.Cover))
+		container.Ops = &ops
+	}
+
+	if s.Multiarch {
+		container.Seccomp |= seccomp.FilterMultiarch
+	}
+
+	if s.Devel {
+		container.Flags |= sandbox.FAllowDevel
+	}
+	if s.Userns {
+		container.Flags |= sandbox.FAllowUserns
+	}
+	if s.Net {
+		container.Flags |= sandbox.FAllowNet
+	}
+	if s.Tty {
+		container.Flags |= sandbox.FAllowTTY
+	}
+
+	if s.MapRealUID {
+		/* some programs fail to connect to dbus session running as a different uid
+		so this workaround is introduced to map priv-side caller uid in container */
+		container.Uid = os.Getuid()
+		*uid = container.Uid
+		container.Gid = os.Getgid()
+		*gid = container.Gid
+	} else {
+		*uid = sandbox.OverflowUid()
+		*gid = sandbox.OverflowGid()
+	}
+
+	container.
+		Proc("/proc").
+		Tmpfs(fst.Tmp, 1<<12, 0755)
+
+	if !s.Device {
+		container.Dev("/dev").Mqueue("/dev/mqueue")
+	} else {
+		container.Bind("/dev", "/dev", sandbox.BindWritable|sandbox.BindDevice)
+	}
+
+	/* retrieve paths and hide them if they're made available in the sandbox;
+	this feature tries to improve user experience of permissive defaults, and
+	to warn about issues in custom configuration; it is NOT a security feature
+	and should not be treated as such, ALWAYS be careful with what you bind */
+	var hidePaths []string
+	sc := os.Paths()
+	hidePaths = append(hidePaths, sc.RuntimePath, sc.SharePath)
+	_, systemBusAddr := dbus.Address()
+	if entries, err := dbus.Parse([]byte(systemBusAddr)); err != nil {
+		return nil, nil, err
+	} else {
+		// there is usually only one, do not preallocate
+		for _, entry := range entries {
+			if entry.Method != "unix" {
+				continue
+			}
+			for _, pair := range entry.Values {
+				if pair[0] == "path" {
+					if path.IsAbs(pair[1]) {
+						// get parent dir of socket
+						dir := path.Dir(pair[1])
+						if dir == "." || dir == "/" {
+							os.Printf("dbus socket %q is in an unusual location", pair[1])
+						}
+						hidePaths = append(hidePaths, dir)
+					} else {
+						os.Printf("dbus socket %q is not absolute", pair[1])
+					}
+				}
+			}
+		}
+	}
+	hidePathMatch := make([]bool, len(hidePaths))
+	for i := range hidePaths {
+		if err := evalSymlinks(os, &hidePaths[i]); err != nil {
+			return nil, nil, err
+		}
+	}
+
+	for _, c := range s.Filesystem {
+		if c == nil {
+			continue
+		}
+
+		if !path.IsAbs(c.Src) {
+			return nil, nil, fmt.Errorf("src path %q is not absolute", c.Src)
+		}
+
+		dest := c.Dst
+		if c.Dst == "" {
+			dest = c.Src
+		} else if !path.IsAbs(dest) {
+			return nil, nil, fmt.Errorf("dst path %q is not absolute", dest)
+		}
+
+		srcH := c.Src
+		if err := evalSymlinks(os, &srcH); err != nil {
+			return nil, nil, err
+		}
+
+		for i := range hidePaths {
+			// skip matched entries
+			if hidePathMatch[i] {
+				continue
+			}
+
+			if ok, err := deepContainsH(srcH, hidePaths[i]); err != nil {
+				return nil, nil, err
+			} else if ok {
+				hidePathMatch[i] = true
+				os.Printf("hiding paths from %q", c.Src)
+			}
+		}
+
+		var flags int
+		if c.Write {
+			flags |= sandbox.BindWritable
+		}
+		if c.Device {
+			flags |= sandbox.BindDevice | sandbox.BindWritable
+		}
+		if !c.Must {
+			flags |= sandbox.BindOptional
+		}
+		container.Bind(c.Src, dest, flags)
+	}
+
+	// cover matched paths
+	for i, ok := range hidePathMatch {
+		if ok {
+			container.Tmpfs(hidePaths[i], 1<<13, 0755)
+		}
+	}
+
+	for _, l := range s.Link {
+		container.Link(l[0], l[1])
+	}
+
+	return container, maps.Clone(s.Env), nil
+}
+
+func evalSymlinks(os sys.State, v *string) error {
+	if p, err := os.EvalSymlinks(*v); err != nil {
+		if !errors.Is(err, fs.ErrNotExist) {
+			return err
+		}
+		os.Printf("path %q does not yet exist", *v)
+	} else {
+		*v = p
+	}
+	return nil
+}

internal/app/instance/common/path.go

@@ -1,4 +1,4 @@
-package fst
+package common
 
 import (
 	"path/filepath"

internal/app/instance/common/path_test.go

@@ -1,4 +1,4 @@
-package fst
+package common
 
 import (
 	"testing"

internal/app/instance/errors.go

@@ -0,0 +1,17 @@
+package instance
+
+import (
+	"syscall"
+
+	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/internal/setuid"
+)
+
+func PrintRunStateErr(whence int, rs *app.RunState, runErr error) (code int) {
+	switch whence {
+	case ISetuid:
+		return setuid.PrintRunStateErr(rs, runErr)
+	default:
+		panic(syscall.EINVAL)
+	}
+}

internal/app/instance/new.go

@@ -0,0 +1,33 @@
+// Package instance exposes cross-package implementation details and provides constructors for builtin implementations.
+package instance
+
+import (
+	"context"
+	"log"
+	"syscall"
+
+	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/internal/setuid"
+	"git.gensokyo.uk/security/fortify/internal/sys"
+)
+
+const (
+	ISetuid = iota
+)
+
+func New(whence int, ctx context.Context, os sys.State) (app.App, error) {
+	switch whence {
+	case ISetuid:
+		return setuid.New(ctx, os)
+	default:
+		return nil, syscall.EINVAL
+	}
+}
+
+func MustNew(whence int, ctx context.Context, os sys.State) app.App {
+	a, err := New(whence, ctx, os)
+	if err != nil {
+		log.Fatalf("cannot create app: %v", err)
+	}
+	return a
+}

internal/app/instance/shim.go

@@ -0,0 +1,6 @@
+package instance
+
+import "git.gensokyo.uk/security/fortify/internal/app/internal/setuid"
+
+// ShimMain is the main function of the shim process and runs as the unconstrained target user.
+func ShimMain() { setuid.ShimMain() }

internal/app/internal/setuid/app.go

@@ -0,0 +1,74 @@
+package setuid
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"git.gensokyo.uk/security/fortify/fst"
+	. "git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/sys"
+)
+
+func New(ctx context.Context, os sys.State) (App, error) {
+	a := new(app)
+	a.sys = os
+	a.ctx = ctx
+
+	id := new(ID)
+	err := NewAppID(id)
+	a.id = newID(id)
+
+	return a, err
+}
+
+type app struct {
+	id  *stringPair[ID]
+	sys sys.State
+	ctx context.Context
+
+	*outcome
+	mu sync.RWMutex
+}
+
+func (a *app) ID() ID { a.mu.RLock(); defer a.mu.RUnlock(); return a.id.unwrap() }
+
+func (a *app) String() string {
+	if a == nil {
+		return "(invalid app)"
+	}
+
+	a.mu.RLock()
+	defer a.mu.RUnlock()
+
+	if a.outcome != nil {
+		if a.outcome.user.uid == nil {
+			return fmt.Sprintf("(sealed app %s with invalid uid)", a.id)
+		}
+		return fmt.Sprintf("(sealed app %s as uid %s)", a.id, a.outcome.user.uid)
+	}
+
+	return fmt.Sprintf("(unsealed app %s)", a.id)
+}
+
+func (a *app) Seal(config *fst.Config) (SealedApp, error) {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+
+	if a.outcome != nil {
+		panic("app sealed twice")
+	}
+	if config == nil {
+		return nil, fmsg.WrapError(ErrConfig,
+			"attempted to seal app with nil config")
+	}
+
+	seal := new(outcome)
+	seal.id = a.id
+	err := seal.finalise(a.ctx, a.sys, config)
+	if err == nil {
+		a.outcome = seal
+	}
+	return seal, err
+}

internal/app/internal/setuid/app_nixos_test.go

@@ -0,0 +1,145 @@
+package setuid_test
+
+import (
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/sandbox"
+	"git.gensokyo.uk/security/fortify/system"
+)
+
+var testCasesNixos = []sealTestCase{
+	{
+		"nixos chromium direct wayland", new(stubNixOS),
+		&fst.Config{
+			ID:          "org.chromium.Chromium",
+			Path:        "/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start",
+			Enablements: system.EWayland | system.EDBus | system.EPulse,
+
+			Container: &fst.ContainerConfig{
+				Userns: true, Net: true, MapRealUID: true, Env: nil, AutoEtc: true,
+				Filesystem: []*fst.FilesystemConfig{
+					{Src: "/bin", Must: true}, {Src: "/usr/bin", Must: true},
+					{Src: "/nix/store", Must: true}, {Src: "/run/current-system", Must: true},
+					{Src: "/sys/block"}, {Src: "/sys/bus"}, {Src: "/sys/class"}, {Src: "/sys/dev"}, {Src: "/sys/devices"},
+					{Src: "/run/opengl-driver", Must: true}, {Src: "/dev/dri", Device: true},
+				},
+				Cover: []string{"/var/run/nscd"},
+			},
+			SystemBus: &dbus.Config{
+				Talk:   []string{"org.bluez", "org.freedesktop.Avahi", "org.freedesktop.UPower"},
+				Filter: true,
+			},
+			SessionBus: &dbus.Config{
+				Talk: []string{
+					"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
+					"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
+					"org.kde.kwalletd5", "org.kde.kwalletd6",
+				},
+				Own: []string{
+					"org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.chromium.*",
+				},
+				Call: map[string]string{}, Broadcast: map[string]string{},
+				Filter: true,
+			},
+			DirectWayland: true,
+
+			Username: "u0_a1",
+			Data:     "/var/lib/persist/module/fortify/0/1",
+			Identity: 1, Groups: []string{},
+		},
+		app.ID{
+			0x8e, 0x2c, 0x76, 0xb0,
+			0x66, 0xda, 0xbe, 0x57,
+			0x4c, 0xf0, 0x73, 0xbd,
+			0xb4, 0x6e, 0xb5, 0xc1,
+		},
+		system.New(1000001).
+			Ensure("/tmp/fortify.1971", 0711).
+			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
+			Ensure("/tmp/fortify.1971/tmpdir/1", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/1", acl.Read, acl.Write, acl.Execute).
+			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
+			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
+			UpdatePermType(system.EWayland, "/run/user/1971/wayland-0", acl.Read, acl.Write, acl.Execute).
+			Ephemeral(system.Process, "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1", acl.Execute).
+			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/pulse").
+			CopyFile(nil, "/home/ophestra/xdg/config/pulse/cookie", 256, 256).
+			Ephemeral(system.Process, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1", 0711).
+			MustProxyDBus("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", &dbus.Config{
+				Talk: []string{
+					"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
+					"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
+					"org.kde.kwalletd5", "org.kde.kwalletd6",
+				},
+				Own: []string{
+					"org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.chromium.*",
+				},
+				Call: map[string]string{}, Broadcast: map[string]string{},
+				Filter: true,
+			}, "/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", &dbus.Config{
+				Talk: []string{
+					"org.bluez",
+					"org.freedesktop.Avahi",
+					"org.freedesktop.UPower",
+				},
+				Filter: true,
+			}).
+			UpdatePerm("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", acl.Read, acl.Write).
+			UpdatePerm("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", acl.Read, acl.Write),
+		&sandbox.Params{
+			Uid:   1971,
+			Gid:   100,
+			Flags: sandbox.FAllowNet | sandbox.FAllowUserns,
+			Dir:   "/var/lib/persist/module/fortify/0/1",
+			Path:  "/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start",
+			Args:  []string{"/nix/store/yqivzpzzn7z5x0lq9hmbzygh45d8rhqd-chromium-start"},
+			Env: []string{
+				"DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1971/bus",
+				"DBUS_SYSTEM_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket",
+				"HOME=/var/lib/persist/module/fortify/0/1",
+				"PULSE_COOKIE=" + fst.Tmp + "/pulse-cookie",
+				"PULSE_SERVER=unix:/run/user/1971/pulse/native",
+				"SHELL=/run/current-system/sw/bin/zsh",
+				"TERM=xterm-256color",
+				"USER=u0_a1",
+				"WAYLAND_DISPLAY=wayland-0",
+				"XDG_RUNTIME_DIR=/run/user/1971",
+				"XDG_SESSION_CLASS=user",
+				"XDG_SESSION_TYPE=tty",
+			},
+			Ops: new(sandbox.Ops).
+				Proc("/proc").
+				Tmpfs(fst.Tmp, 4096, 0755).
+				Dev("/dev").Mqueue("/dev/mqueue").
+				Bind("/bin", "/bin", 0).
+				Bind("/usr/bin", "/usr/bin", 0).
+				Bind("/nix/store", "/nix/store", 0).
+				Bind("/run/current-system", "/run/current-system", 0).
+				Bind("/sys/block", "/sys/block", sandbox.BindOptional).
+				Bind("/sys/bus", "/sys/bus", sandbox.BindOptional).
+				Bind("/sys/class", "/sys/class", sandbox.BindOptional).
+				Bind("/sys/dev", "/sys/dev", sandbox.BindOptional).
+				Bind("/sys/devices", "/sys/devices", sandbox.BindOptional).
+				Bind("/run/opengl-driver", "/run/opengl-driver", 0).
+				Bind("/dev/dri", "/dev/dri", sandbox.BindDevice|sandbox.BindWritable|sandbox.BindOptional).
+				Etc("/etc", "8e2c76b066dabe574cf073bdb46eb5c1").
+				Tmpfs("/run/user", 4096, 0755).
+				Tmpfs("/run/user/1971", 8388608, 0700).
+				Bind("/tmp/fortify.1971/tmpdir/1", "/tmp", sandbox.BindWritable).
+				Bind("/var/lib/persist/module/fortify/0/1", "/var/lib/persist/module/fortify/0/1", sandbox.BindWritable).
+				Place("/etc/passwd", []byte("u0_a1:x:1971:100:Fortify:/var/lib/persist/module/fortify/0/1:/run/current-system/sw/bin/zsh\n")).
+				Place("/etc/group", []byte("fortify:x:100:\n")).
+				Bind("/run/user/1971/wayland-0", "/run/user/1971/wayland-0", 0).
+				Bind("/run/user/1971/fortify/8e2c76b066dabe574cf073bdb46eb5c1/pulse", "/run/user/1971/pulse/native", 0).
+				Place(fst.Tmp+"/pulse-cookie", nil).
+				Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/bus", "/run/user/1971/bus", 0).
+				Bind("/tmp/fortify.1971/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket", "/run/dbus/system_bus_socket", 0).
+				Tmpfs("/var/run/nscd", 8192, 0755),
+		},
+	},
+}

internal/app/internal/setuid/app_pd_test.go

@@ -0,0 +1,216 @@
+package setuid_test
+
+import (
+	"os"
+
+	"git.gensokyo.uk/security/fortify/acl"
+	"git.gensokyo.uk/security/fortify/dbus"
+	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/sandbox"
+	"git.gensokyo.uk/security/fortify/system"
+)
+
+var testCasesPd = []sealTestCase{
+	{
+		"nixos permissive defaults no enablements", new(stubNixOS),
+		&fst.Config{Username: "chronos", Data: "/home/chronos"},
+		app.ID{
+			0x4a, 0x45, 0x0b, 0x65,
+			0x96, 0xd7, 0xbc, 0x15,
+			0xbd, 0x01, 0x78, 0x0e,
+			0xb9, 0xa6, 0x07, 0xac,
+		},
+		system.New(1000000).
+			Ensure("/tmp/fortify.1971", 0711).
+			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
+			Ensure("/tmp/fortify.1971/tmpdir/0", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/0", acl.Read, acl.Write, acl.Execute),
+		&sandbox.Params{
+			Flags: sandbox.FAllowNet | sandbox.FAllowUserns | sandbox.FAllowTTY,
+			Dir:   "/home/chronos",
+			Path:  "/run/current-system/sw/bin/zsh",
+			Args:  []string{"/run/current-system/sw/bin/zsh"},
+			Env: []string{
+				"HOME=/home/chronos",
+				"SHELL=/run/current-system/sw/bin/zsh",
+				"TERM=xterm-256color",
+				"USER=chronos",
+				"XDG_RUNTIME_DIR=/run/user/65534",
+				"XDG_SESSION_CLASS=user",
+				"XDG_SESSION_TYPE=tty",
+			},
+			Ops: new(sandbox.Ops).
+				Proc("/proc").
+				Tmpfs(fst.Tmp, 4096, 0755).
+				Dev("/dev").Mqueue("/dev/mqueue").
+				Bind("/bin", "/bin", sandbox.BindWritable).
+				Bind("/boot", "/boot", sandbox.BindWritable).
+				Bind("/home", "/home", sandbox.BindWritable).
+				Bind("/lib", "/lib", sandbox.BindWritable).
+				Bind("/lib64", "/lib64", sandbox.BindWritable).
+				Bind("/nix", "/nix", sandbox.BindWritable).
+				Bind("/root", "/root", sandbox.BindWritable).
+				Bind("/run", "/run", sandbox.BindWritable).
+				Bind("/srv", "/srv", sandbox.BindWritable).
+				Bind("/sys", "/sys", sandbox.BindWritable).
+				Bind("/usr", "/usr", sandbox.BindWritable).
+				Bind("/var", "/var", sandbox.BindWritable).
+				Bind("/dev/kvm", "/dev/kvm", sandbox.BindWritable|sandbox.BindDevice|sandbox.BindOptional).
+				Tmpfs("/run/user/1971", 8192, 0755).
+				Tmpfs("/run/dbus", 8192, 0755).
+				Etc("/etc", "4a450b6596d7bc15bd01780eb9a607ac").
+				Tmpfs("/run/user", 4096, 0755).
+				Tmpfs("/run/user/65534", 8388608, 0700).
+				Bind("/tmp/fortify.1971/tmpdir/0", "/tmp", sandbox.BindWritable).
+				Bind("/home/chronos", "/home/chronos", sandbox.BindWritable).
+				Place("/etc/passwd", []byte("chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n")).
+				Place("/etc/group", []byte("fortify:x:65534:\n")).
+				Tmpfs("/var/run/nscd", 8192, 0755),
+		},
+	},
+	{
+		"nixos permissive defaults chromium", new(stubNixOS),
+		&fst.Config{
+			ID:       "org.chromium.Chromium",
+			Args:     []string{"zsh", "-c", "exec chromium "},
+			Identity: 9,
+			Groups:   []string{"video"},
+			Username: "chronos",
+			Data:     "/home/chronos",
+			SessionBus: &dbus.Config{
+				Talk: []string{
+					"org.freedesktop.Notifications",
+					"org.freedesktop.FileManager1",
+					"org.freedesktop.ScreenSaver",
+					"org.freedesktop.secrets",
+					"org.kde.kwalletd5",
+					"org.kde.kwalletd6",
+					"org.gnome.SessionManager",
+				},
+				Own: []string{
+					"org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.chromium.*",
+				},
+				Call: map[string]string{
+					"org.freedesktop.portal.*": "*",
+				},
+				Broadcast: map[string]string{
+					"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
+				},
+				Filter: true,
+			},
+			SystemBus: &dbus.Config{
+				Talk: []string{
+					"org.bluez",
+					"org.freedesktop.Avahi",
+					"org.freedesktop.UPower",
+				},
+				Filter: true,
+			},
+			Enablements: system.EWayland | system.EDBus | system.EPulse,
+		},
+		app.ID{
+			0xeb, 0xf0, 0x83, 0xd1,
+			0xb1, 0x75, 0x91, 0x17,
+			0x82, 0xd4, 0x13, 0x36,
+			0x9b, 0x64, 0xce, 0x7c,
+		},
+		system.New(1000009).
+			Ensure("/tmp/fortify.1971", 0711).
+			Ensure("/tmp/fortify.1971/tmpdir", 0700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir", acl.Execute).
+			Ensure("/tmp/fortify.1971/tmpdir/9", 01700).UpdatePermType(system.User, "/tmp/fortify.1971/tmpdir/9", acl.Read, acl.Write, acl.Execute).
+			Ephemeral(system.Process, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c", 0711).
+			Wayland(new(*os.File), "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/wayland", "/run/user/1971/wayland-0", "org.chromium.Chromium", "ebf083d1b175911782d413369b64ce7c").
+			Ensure("/run/user/1971/fortify", 0700).UpdatePermType(system.User, "/run/user/1971/fortify", acl.Execute).
+			Ensure("/run/user/1971", 0700).UpdatePermType(system.User, "/run/user/1971", acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
+			Ephemeral(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", 0700).UpdatePermType(system.Process, "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c", acl.Execute).
+			Link("/run/user/1971/pulse/native", "/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse").
+			CopyFile(new([]byte), "/home/ophestra/xdg/config/pulse/cookie", 256, 256).
+			MustProxyDBus("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", &dbus.Config{
+				Talk: []string{
+					"org.freedesktop.Notifications",
+					"org.freedesktop.FileManager1",
+					"org.freedesktop.ScreenSaver",
+					"org.freedesktop.secrets",
+					"org.kde.kwalletd5",
+					"org.kde.kwalletd6",
+					"org.gnome.SessionManager",
+				},
+				Own: []string{
+					"org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+					"org.mpris.MediaPlayer2.chromium.*",
+				},
+				Call: map[string]string{
+					"org.freedesktop.portal.*": "*",
+				},
+				Broadcast: map[string]string{
+					"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
+				},
+				Filter: true,
+			}, "/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", &dbus.Config{
+				Talk: []string{
+					"org.bluez",
+					"org.freedesktop.Avahi",
+					"org.freedesktop.UPower",
+				},
+				Filter: true,
+			}).
+			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", acl.Read, acl.Write).
+			UpdatePerm("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", acl.Read, acl.Write),
+		&sandbox.Params{
+			Flags: sandbox.FAllowNet | sandbox.FAllowUserns | sandbox.FAllowTTY,
+			Dir:   "/home/chronos",
+			Path:  "/run/current-system/sw/bin/zsh",
+			Args:  []string{"zsh", "-c", "exec chromium "},
+			Env: []string{
+				"DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/65534/bus",
+				"DBUS_SYSTEM_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket",
+				"HOME=/home/chronos",
+				"PULSE_COOKIE=" + fst.Tmp + "/pulse-cookie",
+				"PULSE_SERVER=unix:/run/user/65534/pulse/native",
+				"SHELL=/run/current-system/sw/bin/zsh",
+				"TERM=xterm-256color",
+				"USER=chronos",
+				"WAYLAND_DISPLAY=wayland-0",
+				"XDG_RUNTIME_DIR=/run/user/65534",
+				"XDG_SESSION_CLASS=user",
+				"XDG_SESSION_TYPE=tty",
+			},
+			Ops: new(sandbox.Ops).
+				Proc("/proc").
+				Tmpfs(fst.Tmp, 4096, 0755).
+				Dev("/dev").Mqueue("/dev/mqueue").
+				Bind("/bin", "/bin", sandbox.BindWritable).
+				Bind("/boot", "/boot", sandbox.BindWritable).
+				Bind("/home", "/home", sandbox.BindWritable).
+				Bind("/lib", "/lib", sandbox.BindWritable).
+				Bind("/lib64", "/lib64", sandbox.BindWritable).
+				Bind("/nix", "/nix", sandbox.BindWritable).
+				Bind("/root", "/root", sandbox.BindWritable).
+				Bind("/run", "/run", sandbox.BindWritable).
+				Bind("/srv", "/srv", sandbox.BindWritable).
+				Bind("/sys", "/sys", sandbox.BindWritable).
+				Bind("/usr", "/usr", sandbox.BindWritable).
+				Bind("/var", "/var", sandbox.BindWritable).
+				Bind("/dev/dri", "/dev/dri", sandbox.BindWritable|sandbox.BindDevice|sandbox.BindOptional).
+				Bind("/dev/kvm", "/dev/kvm", sandbox.BindWritable|sandbox.BindDevice|sandbox.BindOptional).
+				Tmpfs("/run/user/1971", 8192, 0755).
+				Tmpfs("/run/dbus", 8192, 0755).
+				Etc("/etc", "ebf083d1b175911782d413369b64ce7c").
+				Tmpfs("/run/user", 4096, 0755).
+				Tmpfs("/run/user/65534", 8388608, 0700).
+				Bind("/tmp/fortify.1971/tmpdir/9", "/tmp", sandbox.BindWritable).
+				Bind("/home/chronos", "/home/chronos", sandbox.BindWritable).
+				Place("/etc/passwd", []byte("chronos:x:65534:65534:Fortify:/home/chronos:/run/current-system/sw/bin/zsh\n")).
+				Place("/etc/group", []byte("fortify:x:65534:\n")).
+				Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/wayland", "/run/user/65534/wayland-0", 0).
+				Bind("/run/user/1971/fortify/ebf083d1b175911782d413369b64ce7c/pulse", "/run/user/65534/pulse/native", 0).
+				Place(fst.Tmp+"/pulse-cookie", nil).
+				Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/bus", "/run/user/65534/bus", 0).
+				Bind("/tmp/fortify.1971/ebf083d1b175911782d413369b64ce7c/system_bus_socket", "/run/dbus/system_bus_socket", 0).
+				Tmpfs("/var/run/nscd", 8192, 0755),
+		},
+	},
+}

internal/app/internal/setuid/app_stub_test.go

@@ -1,4 +1,4 @@
-package app_test
+package setuid_test
 
 import (
 	"fmt"
@@ -7,7 +7,7 @@ import (
 	"os/user"
 	"strconv"
 
-	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
 )
 
 // fs methods are not implemented using a real FS
@@ -125,8 +125,8 @@ func (s *stubNixOS) Open(name string) (fs.File, error) {
 	}
 }
 
-func (s *stubNixOS) Paths() fst.Paths {
+func (s *stubNixOS) Paths() app.Paths {
-	return fst.Paths{
+	return app.Paths{
 		SharePath:   "/tmp/fortify.1971",
 		RuntimePath: "/run/user/1971",
 		RunDirPath:  "/run/user/1971/fortify",

internal/app/internal/setuid/app_test.go

@@ -1,4 +1,4 @@
-package app_test
+package setuid_test
 
 import (
 	"encoding/json"
@@ -9,6 +9,7 @@ import (
 
 	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/internal/setuid"
 	"git.gensokyo.uk/security/fortify/internal/sys"
 	"git.gensokyo.uk/security/fortify/sandbox"
 	"git.gensokyo.uk/security/fortify/system"
@@ -18,7 +19,7 @@ type sealTestCase struct {
 	name          string
 	os            sys.State
 	config        *fst.Config
-	id            fst.ID
+	id            app.ID
 	wantSys       *system.I
 	wantContainer *sandbox.Params
 }
@@ -28,7 +29,7 @@ func TestApp(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
-			a := app.NewWithID(tc.id, tc.os)
+			a := setuid.NewWithID(tc.id, tc.os)
 			var (
 				gotSys       *system.I
 				gotContainer *sandbox.Params
@@ -38,7 +39,7 @@ func TestApp(t *testing.T) {
 					t.Errorf("Seal: error = %v", err)
 					return
 				} else {
-					gotSys, gotContainer = app.AppIParams(a, sa)
+					gotSys, gotContainer = setuid.AppIParams(a, sa)
 				}
 			}) {
 				return

internal/app/internal/setuid/errors.go

@@ -1,14 +1,16 @@
-package app
+package setuid
 
 import (
 	"errors"
 	"log"
 
-	"git.gensokyo.uk/security/fortify/fst"
+	. "git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
-func PrintRunStateErr(rs *fst.RunState, runErr error) {
+func PrintRunStateErr(rs *RunState, runErr error) (code int) {
+	code = rs.ExitStatus()
+
 	if runErr != nil {
 		if rs.Time == nil {
 			fmsg.PrintBaseError(runErr, "cannot start app:")
@@ -49,8 +51,8 @@ func PrintRunStateErr(rs *fst.RunState, runErr error) {
 			}
 		}
 
-		if rs.ExitCode == 0 {
+		if code == 0 {
-			rs.ExitCode = 126
+			code = 126
 		}
 	}
 
@@ -97,13 +99,14 @@ func PrintRunStateErr(rs *fst.RunState, runErr error) {
 		}
 
 	out:
-		if rs.ExitCode == 0 {
+		if code == 0 {
-			rs.ExitCode = 128
+			code = 128
 		}
 	}
 	if rs.WaitErr != nil {
-		log.Println("inner wait failed:", rs.WaitErr)
+		fmsg.Verbosef("wait: %v", rs.WaitErr)
 	}
+	return
 }
 
 // StateStoreError is returned for a failed state save
@@ -121,7 +124,7 @@ type StateStoreError struct {
 }
 
 // save saves arbitrary errors in [StateStoreError] once.
-func (e *StateStoreError) save(errs []error) {
+func (e *StateStoreError) save(errs ...error) {
 	if len(errs) == 0 || e.Err != nil {
 		panic("invalid call to save")
 	}

internal/app/internal/setuid/export_test.go

@@ -1,20 +1,20 @@
-package app
+package setuid
 
 import (
-	"git.gensokyo.uk/security/fortify/fst"
+	. "git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/sys"
 	"git.gensokyo.uk/security/fortify/sandbox"
 	"git.gensokyo.uk/security/fortify/system"
 )
 
-func NewWithID(id fst.ID, os sys.State) fst.App {
+func NewWithID(id ID, os sys.State) App {
 	a := new(app)
 	a.id = newID(&id)
 	a.sys = os
 	return a
 }
 
-func AppIParams(a fst.App, sa fst.SealedApp) (*system.I, *sandbox.Params) {
+func AppIParams(a App, sa SealedApp) (*system.I, *sandbox.Params) {
 	v := a.(*app)
 	seal := sa.(*outcome)
 	if v.outcome != seal || v.id != seal.id {

internal/app/internal/setuid/process.go

@@ -0,0 +1,195 @@
+package setuid
+
+import (
+	"context"
+	"encoding/gob"
+	"errors"
+	"log"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"git.gensokyo.uk/security/fortify/internal"
+	. "git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
+	"git.gensokyo.uk/security/fortify/internal/state"
+	"git.gensokyo.uk/security/fortify/sandbox"
+	"git.gensokyo.uk/security/fortify/system"
+)
+
+const shimWaitTimeout = 5 * time.Second
+
+func (seal *outcome) Run(rs *RunState) error {
+	if !seal.f.CompareAndSwap(false, true) {
+		// run does much more than just starting a process; calling it twice, even if the first call fails, will result
+		// in inconsistent state that is impossible to clean up; return here to limit damage and hopefully give the
+		// other Run a chance to return
+		return errors.New("outcome: attempted to run twice")
+	}
+
+	if rs == nil {
+		panic("invalid state")
+	}
+
+	// read comp value early to allow for early failure
+	fsuPath := internal.MustFsuPath()
+
+	if err := seal.sys.Commit(seal.ctx); err != nil {
+		return err
+	}
+	store := state.NewMulti(seal.runDirPath)
+	deferredStoreFunc := func(c state.Cursor) error { return nil } // noop until state in store
+	defer func() {
+		var revertErr error
+		storeErr := new(StateStoreError)
+		storeErr.Inner, storeErr.DoErr = store.Do(seal.user.aid.unwrap(), func(c state.Cursor) {
+			revertErr = func() error {
+				storeErr.InnerErr = deferredStoreFunc(c)
+
+				var rt system.Enablement
+				ec := system.Process
+				if states, err := c.Load(); err != nil {
+					// revert per-process state here to limit damage
+					storeErr.OpErr = err
+					return seal.sys.Revert((*system.Criteria)(&ec))
+				} else {
+					if l := len(states); l == 0 {
+						ec |= system.User
+					} else {
+						fmsg.Verbosef("found %d instances, cleaning up without user-scoped operations", l)
+					}
+
+					// accumulate enablements of remaining launchers
+					for i, s := range states {
+						if s.Config != nil {
+							rt |= s.Config.Enablements
+						} else {
+							log.Printf("state entry %d does not contain config", i)
+						}
+					}
+				}
+				ec |= rt ^ (system.EWayland | system.EX11 | system.EDBus | system.EPulse)
+				if fmsg.Load() {
+					if ec > 0 {
+						fmsg.Verbose("reverting operations scope", system.TypeString(ec))
+					}
+				}
+
+				return seal.sys.Revert((*system.Criteria)(&ec))
+			}()
+		})
+		storeErr.save(revertErr, store.Close())
+		rs.RevertErr = storeErr.equiv("error during cleanup:")
+	}()
+
+	ctx, cancel := context.WithCancel(seal.ctx)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, fsuPath)
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
+	cmd.Dir = "/" // container init enters final working directory
+	// shim runs in the same session as monitor; see shim.go for behaviour
+	cmd.Cancel = func() error { return cmd.Process.Signal(syscall.SIGCONT) }
+
+	var e *gob.Encoder
+	if fd, encoder, err := sandbox.Setup(&cmd.ExtraFiles); err != nil {
+		return fmsg.WrapErrorSuffix(err,
+			"cannot create shim setup pipe:")
+	} else {
+		e = encoder
+		cmd.Env = []string{
+			// passed through to shim by fsu
+			shimEnv + "=" + strconv.Itoa(fd),
+			// interpreted by fsu
+			"FORTIFY_APP_ID=" + seal.user.aid.String(),
+		}
+	}
+
+	if len(seal.user.supp) > 0 {
+		fmsg.Verbosef("attaching supplementary group ids %s", seal.user.supp)
+		// interpreted by fsu
+		cmd.Env = append(cmd.Env, "FORTIFY_GROUPS="+strings.Join(seal.user.supp, " "))
+	}
+
+	fmsg.Verbosef("setuid helper at %s", fsuPath)
+	fmsg.Suspend()
+	if err := cmd.Start(); err != nil {
+		return fmsg.WrapErrorSuffix(err,
+			"cannot start setuid wrapper:")
+	}
+	rs.SetStart()
+
+	// this prevents blocking forever on an early failure
+	waitErr, setupErr := make(chan error, 1), make(chan error, 1)
+	go func() { waitErr <- cmd.Wait(); cancel() }()
+	go func() { setupErr <- e.Encode(&shimParams{os.Getpid(), seal.container, seal.user.data, fmsg.Load()}) }()
+
+	select {
+	case err := <-setupErr:
+		if err != nil {
+			fmsg.Resume()
+			return fmsg.WrapErrorSuffix(err,
+				"cannot transmit shim config:")
+		}
+
+	case <-ctx.Done():
+		fmsg.Resume()
+		return fmsg.WrapError(syscall.ECANCELED,
+			"shim setup canceled")
+	}
+
+	// returned after blocking on waitErr
+	var earlyStoreErr = new(StateStoreError)
+	{
+		// shim accepted setup payload, create process state
+		sd := state.State{
+			ID:   seal.id.unwrap(),
+			PID:  cmd.Process.Pid,
+			Time: *rs.Time,
+		}
+		earlyStoreErr.Inner, earlyStoreErr.DoErr = store.Do(seal.user.aid.unwrap(), func(c state.Cursor) {
+			earlyStoreErr.InnerErr = c.Save(&sd, seal.ct)
+		})
+	}
+
+	// state in store at this point, destroy defunct state entry on return
+	deferredStoreFunc = func(c state.Cursor) error { return c.Destroy(seal.id.unwrap()) }
+
+	waitTimeout := make(chan struct{})
+	go func() { <-seal.ctx.Done(); time.Sleep(shimWaitTimeout); close(waitTimeout) }()
+
+	select {
+	case rs.WaitErr = <-waitErr:
+		rs.WaitStatus = cmd.ProcessState.Sys().(syscall.WaitStatus)
+		if fmsg.Load() {
+			switch {
+			case rs.Exited():
+				fmsg.Verbosef("process %d exited with code %d", cmd.Process.Pid, rs.ExitStatus())
+			case rs.CoreDump():
+				fmsg.Verbosef("process %d dumped core", cmd.Process.Pid)
+			case rs.Signaled():
+				fmsg.Verbosef("process %d got %s", cmd.Process.Pid, rs.Signal())
+			default:
+				fmsg.Verbosef("process %d exited with status %#x", cmd.Process.Pid, rs.WaitStatus)
+			}
+		}
+	case <-waitTimeout:
+		rs.WaitErr = syscall.ETIMEDOUT
+		fmsg.Resume()
+		log.Printf("process %d did not terminate", cmd.Process.Pid)
+	}
+
+	fmsg.Resume()
+	if seal.sync != nil {
+		if err := seal.sync.Close(); err != nil {
+			log.Printf("cannot close wayland security context: %v", err)
+		}
+	}
+	if seal.dbusMsg != nil {
+		seal.dbusMsg()
+	}
+
+	return earlyStoreErr.equiv("cannot save process state:")
+}

internal/app/internal/setuid/seal.go

@@ -1,4 +1,4 @@
-package app
+package setuid
 
 import (
 	"bytes"
@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"maps"
 	"os"
 	"path"
 	"regexp"
@@ -21,6 +20,8 @@ import (
 	"git.gensokyo.uk/security/fortify/dbus"
 	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/internal"
+	. "git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/instance/common"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/internal/sys"
 	"git.gensokyo.uk/security/fortify/sandbox"
@@ -65,7 +66,7 @@ var posixUsername = regexp.MustCompilePOSIX("^[a-z_]([A-Za-z0-9_-]{0,31}|[A-Za-z
 // outcome stores copies of various parts of [fst.Config]
 type outcome struct {
 	// copied from initialising [app]
-	id *stringPair[fst.ID]
+	id *stringPair[ID]
 	// copied from [sys.State] response
 	runDirPath string
 
@@ -86,6 +87,53 @@ type outcome struct {
 	f atomic.Bool
 }
 
+// shareHost holds optional share directory state that must not be accessed directly
+type shareHost struct {
+	// whether XDG_RUNTIME_DIR is used post fsu
+	useRuntimeDir bool
+	// process-specific directory in tmpdir, empty if unused
+	sharePath string
+	// process-specific directory in XDG_RUNTIME_DIR, empty if unused
+	runtimeSharePath string
+
+	seal *outcome
+	sc   Paths
+}
+
+// ensureRuntimeDir must be called if direct access to paths within XDG_RUNTIME_DIR is required
+func (share *shareHost) ensureRuntimeDir() {
+	if share.useRuntimeDir {
+		return
+	}
+	share.useRuntimeDir = true
+	share.seal.sys.Ensure(share.sc.RunDirPath, 0700)
+	share.seal.sys.UpdatePermType(system.User, share.sc.RunDirPath, acl.Execute)
+	share.seal.sys.Ensure(share.sc.RuntimePath, 0700) // ensure this dir in case XDG_RUNTIME_DIR is unset
+	share.seal.sys.UpdatePermType(system.User, share.sc.RuntimePath, acl.Execute)
+}
+
+// instance returns a process-specific share path within tmpdir
+func (share *shareHost) instance() string {
+	if share.sharePath != "" {
+		return share.sharePath
+	}
+	share.sharePath = path.Join(share.sc.SharePath, share.seal.id.String())
+	share.seal.sys.Ephemeral(system.Process, share.sharePath, 0711)
+	return share.sharePath
+}
+
+// runtime returns a process-specific share path within XDG_RUNTIME_DIR
+func (share *shareHost) runtime() string {
+	if share.runtimeSharePath != "" {
+		return share.runtimeSharePath
+	}
+	share.ensureRuntimeDir()
+	share.runtimeSharePath = path.Join(share.sc.RunDirPath, share.seal.id.String())
+	share.seal.sys.Ephemeral(system.Process, share.runtimeSharePath, 0700)
+	share.seal.sys.UpdatePerm(share.runtimeSharePath, acl.Execute)
+	return share.runtimeSharePath
+}
+
 // fsuUser stores post-fsu credentials and metadata
 type fsuUser struct {
 	// application id
@@ -110,11 +158,6 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 	}
 	seal.ctx = ctx
 
-	shellPath := "/bin/sh"
-	if s, ok := sys.LookupEnv(shell); ok && path.IsAbs(s) {
-		shellPath = s
-	}
-
 	{
 		// encode initial configuration for state tracking
 		ct := new(bytes.Buffer)
@@ -126,20 +169,16 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 	}
 
 	// allowed aid range 0 to 9999, this is checked again in fsu
-	if config.Confinement.AppID < 0 || config.Confinement.AppID > 9999 {
+	if config.Identity < 0 || config.Identity > 9999 {
 		return fmsg.WrapError(ErrUser,
-			fmt.Sprintf("aid %d out of range", config.Confinement.AppID))
+			fmt.Sprintf("identity %d out of range", config.Identity))
 	}
 
-	/*
-		Resolve post-fsu user state
-	*/
-
 	seal.user = fsuUser{
-		aid:      newInt(config.Confinement.AppID),
+		aid:      newInt(config.Identity),
-		data:     config.Confinement.Outer,
+		data:     config.Data,
-		home:     config.Confinement.Inner,
+		home:     config.Dir,
-		username: config.Confinement.Username,
+		username: config.Username,
 	}
 	if seal.user.username == "" {
 		seal.user.username = "chronos"
@@ -160,8 +199,8 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 	} else {
 		seal.user.uid = newInt(u)
 	}
-	seal.user.supp = make([]string, len(config.Confinement.Groups))
+	seal.user.supp = make([]string, len(config.Groups))
-	for i, name := range config.Confinement.Groups {
+	for i, name := range config.Groups {
 		if g, err := sys.LookupGroup(name); err != nil {
 			return fmsg.WrapError(err,
 				fmt.Sprintf("unknown group %q", name))
@@ -170,13 +209,18 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		}
 	}
 
-	/*
+	// this also falls back to host path if encountering an invalid path
-		Resolve initial container state
+	if !path.IsAbs(config.Shell) {
-	*/
+		config.Shell = "/bin/sh"
+		if s, ok := sys.LookupEnv(shell); ok && path.IsAbs(s) {
+			config.Shell = s
+		}
+	}
+	// do not use the value of shell before this point
 
 	// permissive defaults
-	if config.Confinement.Sandbox == nil {
+	if config.Container == nil {
-		fmsg.Verbose("sandbox configuration not supplied, PROCEED WITH CAUTION")
+		fmsg.Verbose("container configuration not supplied, PROCEED WITH CAUTION")
 
 		// fsu clears the environment so resolve paths early
 		if !path.IsAbs(config.Path) {
@@ -187,11 +231,11 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 					config.Path = p
 				}
 			} else {
-				config.Path = shellPath
+				config.Path = config.Shell
 			}
 		}
 
-		conf := &fst.SandboxConfig{
+		conf := &fst.ContainerConfig{
 			Userns:  true,
 			Net:     true,
 			Tty:     true,
@@ -224,20 +268,20 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 			conf.Cover = append(conf.Cover, nscd)
 		}
 		// bind GPU stuff
-		if config.Confinement.Enablements&(system.EX11|system.EWayland) != 0 {
+		if config.Enablements&(system.EX11|system.EWayland) != 0 {
 			conf.Filesystem = append(conf.Filesystem, &fst.FilesystemConfig{Src: "/dev/dri", Device: true})
 		}
 		// opportunistically bind kvm
 		conf.Filesystem = append(conf.Filesystem, &fst.FilesystemConfig{Src: "/dev/kvm", Device: true})
 
-		config.Confinement.Sandbox = conf
+		config.Container = conf
 	}
 
 	var mapuid, mapgid *stringPair[int]
 	{
 		var uid, gid int
 		var err error
-		seal.container, seal.env, err = config.Confinement.Sandbox.ToContainer(sys, &uid, &gid)
+		seal.container, seal.env, err = common.NewContainer(config.Container, sys, &uid, &gid)
 		if err != nil {
 			return fmsg.WrapErrorSuffix(err,
 				"cannot initialise container configuration:")
@@ -255,97 +299,80 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		mapuid = newInt(uid)
 		mapgid = newInt(gid)
 		if seal.env == nil {
-			seal.env = make(map[string]string)
+			seal.env = make(map[string]string, 1<<6)
 		}
 	}
 
-	/*
+	if !config.Container.AutoEtc {
-		Initialise externals
+		if config.Container.Etc != "" {
-	*/
+			seal.container.Bind(config.Container.Etc, "/etc", 0)
+		}
+	} else {
+		etcPath := config.Container.Etc
+		if etcPath == "" {
+			etcPath = "/etc"
+		}
+		seal.container.Etc(etcPath, seal.id.String())
+	}
 
-	sc := sys.Paths()
+	// inner XDG_RUNTIME_DIR default formatting of `/run/user/%d` as mapped uid
-	seal.runDirPath = sc.RunDirPath
-	seal.sys = system.New(seal.user.uid.unwrap())
-
-	/*
-		Work directories
-	*/
-
-	// base fortify share path
-	seal.sys.Ensure(sc.SharePath, 0711)
-
-	// outer paths used by the main process
-	seal.sys.Ensure(sc.RunDirPath, 0700)
-	seal.sys.UpdatePermType(system.User, sc.RunDirPath, acl.Execute)
-	seal.sys.Ensure(sc.RuntimePath, 0700) // ensure this dir in case XDG_RUNTIME_DIR is unset
-	seal.sys.UpdatePermType(system.User, sc.RuntimePath, acl.Execute)
-
-	// outer process-specific share directory
-	sharePath := path.Join(sc.SharePath, seal.id.String())
-	seal.sys.Ephemeral(system.Process, sharePath, 0711)
-	// similar to share but within XDG_RUNTIME_DIR
-	sharePathLocal := path.Join(sc.RunDirPath, seal.id.String())
-	seal.sys.Ephemeral(system.Process, sharePathLocal, 0700)
-	seal.sys.UpdatePerm(sharePathLocal, acl.Execute)
-
-	// inner XDG_RUNTIME_DIR default formatting of `/run/user/%d` as post-fsu user
 	innerRuntimeDir := path.Join("/run/user", mapuid.String())
 	seal.container.Tmpfs("/run/user", 1<<12, 0755)
-	seal.container.Tmpfs(innerRuntimeDir, 1<<23, 0755)
+	seal.container.Tmpfs(innerRuntimeDir, 1<<23, 0700)
 	seal.env[xdgRuntimeDir] = innerRuntimeDir
 	seal.env[xdgSessionClass] = "user"
 	seal.env[xdgSessionType] = "tty"
 
-	// outer path for inner /tmp
+	share := &shareHost{seal: seal, sc: sys.Paths()}
+	seal.runDirPath = share.sc.RunDirPath
+	seal.sys = system.New(seal.user.uid.unwrap())
+
 	{
-		tmpdir := path.Join(sc.SharePath, "tmpdir")
+		seal.sys.Ensure(share.sc.SharePath, 0711)
+		tmpdir := path.Join(share.sc.SharePath, "tmpdir")
 		seal.sys.Ensure(tmpdir, 0700)
 		seal.sys.UpdatePermType(system.User, tmpdir, acl.Execute)
 		tmpdirInst := path.Join(tmpdir, seal.user.aid.String())
 		seal.sys.Ensure(tmpdirInst, 01700)
 		seal.sys.UpdatePermType(system.User, tmpdirInst, acl.Read, acl.Write, acl.Execute)
+		// mount inner /tmp from share so it shares persistence and storage behaviour of host /tmp
 		seal.container.Bind(tmpdirInst, "/tmp", sandbox.BindWritable)
 	}
 
-	/*
+	{
-		Passwd database
+		homeDir := "/var/empty"
-	*/
+		if seal.user.home != "" {
+			homeDir = seal.user.home
+		}
+		username := "chronos"
+		if seal.user.username != "" {
+			username = seal.user.username
+		}
+		seal.container.Bind(seal.user.data, homeDir, sandbox.BindWritable)
+		seal.container.Dir = homeDir
+		seal.env["HOME"] = homeDir
+		seal.env["USER"] = username
+		seal.env[shell] = config.Shell
 
-	homeDir := "/var/empty"
+		seal.container.Place("/etc/passwd",
-	if seal.user.home != "" {
+			[]byte(username+":x:"+mapuid.String()+":"+mapgid.String()+":Fortify:"+homeDir+":"+config.Shell+"\n"))
-		homeDir = seal.user.home
+		seal.container.Place("/etc/group",
+			[]byte("fortify:x:"+mapgid.String()+":\n"))
 	}
-	username := "chronos"
-	if seal.user.username != "" {
-		username = seal.user.username
-	}
-	seal.container.Bind(seal.user.data, homeDir, sandbox.BindWritable)
-	seal.container.Dir = homeDir
-	seal.env["HOME"] = homeDir
-	seal.env["USER"] = username
 
-	seal.container.Place("/etc/passwd",
+	// pass TERM for proper terminal I/O in initial process
-		[]byte(username+":x:"+mapuid.String()+":"+mapgid.String()+":Fortify:"+homeDir+":"+shellPath+"\n"))
-	seal.container.Place("/etc/group",
-		[]byte("fortify:x:"+mapgid.String()+":\n"))
-
-	/*
-		Display servers
-	*/
-
-	// pass $TERM for proper terminal I/O in shell
 	if t, ok := sys.LookupEnv(term); ok {
 		seal.env[term] = t
 	}
 
-	if config.Confinement.Enablements&system.EWayland != 0 {
+	if config.Enablements&system.EWayland != 0 {
 		// outer wayland socket (usually `/run/user/%d/wayland-%d`)
 		var socketPath string
 		if name, ok := sys.LookupEnv(wl.WaylandDisplay); !ok {
 			fmsg.Verbose(wl.WaylandDisplay + " is not set, assuming " + wl.FallbackName)
-			socketPath = path.Join(sc.RuntimePath, wl.FallbackName)
+			socketPath = path.Join(share.sc.RuntimePath, wl.FallbackName)
 		} else if !path.IsAbs(name) {
-			socketPath = path.Join(sc.RuntimePath, name)
+			socketPath = path.Join(share.sc.RuntimePath, name)
 		} else {
 			socketPath = name
 		}
@@ -353,25 +380,25 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		innerPath := path.Join(innerRuntimeDir, wl.FallbackName)
 		seal.env[wl.WaylandDisplay] = wl.FallbackName
 
-		if !config.Confinement.Sandbox.DirectWayland { // set up security-context-v1
+		if !config.DirectWayland { // set up security-context-v1
-			socketDir := path.Join(sc.SharePath, "wayland")
-			outerPath := path.Join(socketDir, seal.id.String())
-			seal.sys.Ensure(socketDir, 0711)
 			appID := config.ID
 			if appID == "" {
 				// use instance ID in case app id is not set
 				appID = "uk.gensokyo.fortify." + seal.id.String()
 			}
+			// downstream socket paths
+			outerPath := path.Join(share.instance(), "wayland")
 			seal.sys.Wayland(&seal.sync, outerPath, socketPath, appID, seal.id.String())
 			seal.container.Bind(outerPath, innerPath, 0)
 		} else { // bind mount wayland socket (insecure)
 			fmsg.Verbose("direct wayland access, PROCEED WITH CAUTION")
+			share.ensureRuntimeDir()
 			seal.container.Bind(socketPath, innerPath, 0)
 			seal.sys.UpdatePermType(system.EWayland, socketPath, acl.Read, acl.Write, acl.Execute)
 		}
 	}
 
-	if config.Confinement.Enablements&system.EX11 != 0 {
+	if config.Enablements&system.EX11 != 0 {
 		if d, ok := sys.LookupEnv(display); !ok {
 			return fmsg.WrapError(ErrXDisplay,
 				"DISPLAY is not set")
@@ -382,13 +409,9 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		}
 	}
 
-	/*
+	if config.Enablements&system.EPulse != 0 {
-		PulseAudio server and authentication
-	*/
-
-	if config.Confinement.Enablements&system.EPulse != 0 {
 		// PulseAudio runtime directory (usually `/run/user/%d/pulse`)
-		pulseRuntimeDir := path.Join(sc.RuntimePath, "pulse")
+		pulseRuntimeDir := path.Join(share.sc.RuntimePath, "pulse")
 		// PulseAudio socket (usually `/run/user/%d/pulse/native`)
 		pulseSocket := path.Join(pulseRuntimeDir, "native")
 
@@ -416,7 +439,7 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		}
 
 		// hard link pulse socket into target-executable share
-		innerPulseRuntimeDir := path.Join(sharePathLocal, "pulse")
+		innerPulseRuntimeDir := path.Join(share.runtime(), "pulse")
 		innerPulseSocket := path.Join(innerRuntimeDir, "pulse", "native")
 		seal.sys.Link(pulseSocket, innerPulseRuntimeDir)
 		seal.container.Bind(innerPulseRuntimeDir, innerPulseSocket, 0)
@@ -435,22 +458,19 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		}
 	}
 
-	/*
+	if config.Enablements&system.EDBus != 0 {
-		D-Bus proxy
-	*/
-
-	if config.Confinement.Enablements&system.EDBus != 0 {
 		// ensure dbus session bus defaults
-		if config.Confinement.SessionBus == nil {
+		if config.SessionBus == nil {
-			config.Confinement.SessionBus = dbus.NewConfig(config.ID, true, true)
+			config.SessionBus = dbus.NewConfig(config.ID, true, true)
 		}
 
 		// downstream socket paths
+		sharePath := share.instance()
 		sessionPath, systemPath := path.Join(sharePath, "bus"), path.Join(sharePath, "system_bus_socket")
 
 		// configure dbus proxy
 		if f, err := seal.sys.ProxyDBus(
-			config.Confinement.SessionBus, config.Confinement.SystemBus,
+			config.SessionBus, config.SystemBus,
 			sessionPath, systemPath,
 		); err != nil {
 			return err
@@ -463,7 +483,7 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		seal.env[dbusSessionBusAddress] = "unix:path=" + sessionInner
 		seal.container.Bind(sessionPath, sessionInner, 0)
 		seal.sys.UpdatePerm(sessionPath, acl.Read, acl.Write)
-		if config.Confinement.SystemBus != nil {
+		if config.SystemBus != nil {
 			systemInner := "/run/dbus/system_bus_socket"
 			seal.env[dbusSystemBusAddress] = "unix:path=" + systemInner
 			seal.container.Bind(systemPath, systemInner, 0)
@@ -471,16 +491,12 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 		}
 	}
 
-	/*
+	for _, dest := range config.Container.Cover {
-		Miscellaneous
-	*/
-
-	for _, dest := range config.Confinement.Sandbox.Cover {
 		seal.container.Tmpfs(dest, 1<<13, 0755)
 	}
 
 	// append ExtraPerms last
-	for _, p := range config.Confinement.ExtraPerms {
+	for _, p := range config.ExtraPerms {
 		if p == nil {
 			continue
 		}
@@ -504,11 +520,19 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *fst.Co
 
 	// flatten and sort env for deterministic behaviour
 	seal.container.Env = make([]string, 0, len(seal.env))
-	maps.All(seal.env)(func(k string, v string) bool { seal.container.Env = append(seal.container.Env, k+"="+v); return true })
+	for k, v := range seal.env {
+		if strings.IndexByte(k, '=') != -1 {
+			return fmsg.WrapError(syscall.EINVAL,
+				fmt.Sprintf("invalid environment variable %s", k))
+		}
+		seal.container.Env = append(seal.container.Env, k+"="+v)
+	}
 	slices.Sort(seal.container.Env)
 
-	fmsg.Verbosef("created application seal for uid %s (%s) groups: %v, argv: %s",
+	if fmsg.Load() {
-		seal.user.uid, seal.user.username, config.Confinement.Groups, seal.container.Args)
+		fmsg.Verbosef("created application seal for uid %s (%s) groups: %v, argv: %s, ops: %d",
+			seal.user.uid, seal.user.username, config.Groups, seal.container.Args, len(*seal.container.Ops))
+	}
 
 	return nil
 }

internal/app/internal/setuid/shim.go

@@ -1,26 +1,78 @@
-package app
+package setuid
 
 import (
 	"context"
-	"encoding/gob"
 	"errors"
 	"log"
 	"os"
 	"os/exec"
 	"os/signal"
-	"strconv"
-	"strings"
 	"syscall"
 	"time"
 
 	"git.gensokyo.uk/security/fortify/internal"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/sandbox"
+	"git.gensokyo.uk/security/fortify/sandbox/seccomp"
 )
 
+/*
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <signal.h>
+
+static pid_t f_shim_param_ppid = -1;
+
+// this cannot unblock fmsg since Go code is not async-signal-safe
+static void f_shim_sigaction(int sig, siginfo_t *si, void *ucontext) {
+  if (sig != SIGCONT || si == NULL) {
+    // unreachable
+    fprintf(stderr, "sigaction: sa_sigaction got invalid siginfo\n");
+    return;
+  }
+
+  // monitor requests shim exit
+  if (si->si_pid == f_shim_param_ppid)
+    exit(254);
+
+  fprintf(stderr, "sigaction: got SIGCONT from process %d\n", si->si_pid);
+
+  // shim orphaned before monitor delivers a signal
+  if (getppid() != f_shim_param_ppid)
+    exit(3);
+}
+
+void f_shim_setup_cont_signal(pid_t ppid) {
+  struct sigaction new_action = {0}, old_action = {0};
+  if (sigaction(SIGCONT, NULL, &old_action) != 0)
+    return;
+  if (old_action.sa_handler != SIG_DFL) {
+    errno = ENOTRECOVERABLE;
+    return;
+  }
+
+  new_action.sa_sigaction = f_shim_sigaction;
+  if (sigemptyset(&new_action.sa_mask) != 0)
+    return;
+  new_action.sa_flags = SA_ONSTACK | SA_SIGINFO;
+
+  if (sigaction(SIGCONT, &new_action, NULL) != 0)
+    return;
+
+  errno = 0;
+  f_shim_param_ppid = ppid;
+}
+*/
+import "C"
+
 const shimEnv = "FORTIFY_SHIM"
 
 type shimParams struct {
+	// monitor pid, checked against ppid in signal handler
+	Monitor int
+
 	// finalised container params
 	Container *sandbox.Params
 	// path to outer home directory
@@ -54,6 +106,16 @@ func ShimMain() {
 	} else {
 		internal.InstallFmsg(params.Verbose)
 		closeSetup = f
+
+		// the Go runtime does not expose siginfo_t so SIGCONT is handled in C to check si_pid
+		if _, err = C.f_shim_setup_cont_signal(C.pid_t(params.Monitor)); err != nil {
+			log.Fatalf("cannot install SIGCONT handler: %v", err)
+		}
+
+		// pdeath_signal delivery is checked as if the dying process called kill(2), see kernel/exit.c
+		if _, _, errno := syscall.Syscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(syscall.SIGCONT), 0); errno != 0 {
+			log.Fatalf("cannot set parent-death signal: %v", errno)
+		}
 	}
 
 	if params.Container == nil || params.Container.Ops == nil {
@@ -100,6 +162,11 @@ func ShimMain() {
 	if err := container.Serve(); err != nil {
 		fmsg.PrintBaseError(err, "cannot configure container:")
 	}
+
+	if err := seccomp.Load(seccomp.PresetCommon); err != nil {
+		log.Fatalf("cannot load syscall filter: %v", err)
+	}
+
 	if err := container.Wait(); err != nil {
 		var exitError *exec.ExitError
 		if !errors.As(err, &exitError) {
@@ -112,101 +179,3 @@ func ShimMain() {
 		os.Exit(exitError.ExitCode())
 	}
 }
-
-type shimProcess struct {
-	// user switcher process
-	cmd *exec.Cmd
-	// fallback exit notifier with error returned killing the process
-	killFallback chan error
-	// monitor to shim encoder
-	encoder *gob.Encoder
-}
-
-func (s *shimProcess) Unwrap() *exec.Cmd    { return s.cmd }
-func (s *shimProcess) Fallback() chan error { return s.killFallback }
-
-func (s *shimProcess) String() string {
-	if s.cmd == nil {
-		return "(unused shim manager)"
-	}
-	return s.cmd.String()
-}
-
-func (s *shimProcess) Start(
-	aid string,
-	supp []string,
-) (*time.Time, error) {
-	// prepare user switcher invocation
-	fsuPath := internal.MustFsuPath()
-	s.cmd = exec.Command(fsuPath)
-
-	// pass shim setup pipe
-	if fd, e, err := sandbox.Setup(&s.cmd.ExtraFiles); err != nil {
-		return nil, fmsg.WrapErrorSuffix(err,
-			"cannot create shim setup pipe:")
-	} else {
-		s.encoder = e
-		s.cmd.Env = []string{
-			shimEnv + "=" + strconv.Itoa(fd),
-			"FORTIFY_APP_ID=" + aid,
-		}
-	}
-
-	// format fsu supplementary groups
-	if len(supp) > 0 {
-		fmsg.Verbosef("attaching supplementary group ids %s", supp)
-		s.cmd.Env = append(s.cmd.Env, "FORTIFY_GROUPS="+strings.Join(supp, " "))
-	}
-	s.cmd.Stdin, s.cmd.Stdout, s.cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-	s.cmd.Dir = "/"
-
-	fmsg.Verbose("starting shim via fsu:", s.cmd)
-	// withhold messages to stderr
-	fmsg.Suspend()
-	if err := s.cmd.Start(); err != nil {
-		return nil, fmsg.WrapErrorSuffix(err,
-			"cannot start fsu:")
-	}
-	startTime := time.Now().UTC()
-
-	return &startTime, nil
-}
-
-func (s *shimProcess) Serve(ctx context.Context, params *shimParams) error {
-	// kill shim if something goes wrong and an error is returned
-	s.killFallback = make(chan error, 1)
-	killShim := func() {
-		if err := s.cmd.Process.Signal(os.Interrupt); err != nil {
-			s.killFallback <- err
-		}
-	}
-	defer func() { killShim() }()
-
-	encodeErr := make(chan error)
-	go func() { encodeErr <- s.encoder.Encode(params) }()
-
-	select {
-	// encode return indicates setup completion
-	case err := <-encodeErr:
-		if err != nil {
-			return fmsg.WrapErrorSuffix(err,
-				"cannot transmit shim config:")
-		}
-		killShim = func() {}
-		return nil
-
-	// setup canceled before payload was accepted
-	case <-ctx.Done():
-		err := ctx.Err()
-		if errors.Is(err, context.Canceled) {
-			return fmsg.WrapError(syscall.ECANCELED,
-				"shim setup canceled")
-		}
-		if errors.Is(err, context.DeadlineExceeded) {
-			return fmsg.WrapError(syscall.ETIMEDOUT,
-				"deadline exceeded waiting for shim")
-		}
-		// unreachable
-		return err
-	}
-}

internal/app/internal/setuid/strings.go

@@ -1,13 +1,13 @@
-package app
+package setuid
 
 import (
 	"strconv"
 
-	"git.gensokyo.uk/security/fortify/fst"
+	. "git.gensokyo.uk/security/fortify/internal/app"
 )
 
-func newInt(v int) *stringPair[int]        { return &stringPair[int]{v, strconv.Itoa(v)} }
+func newInt(v int) *stringPair[int] { return &stringPair[int]{v, strconv.Itoa(v)} }
-func newID(id *fst.ID) *stringPair[fst.ID] { return &stringPair[fst.ID]{*id, id.String()} }
+func newID(id *ID) *stringPair[ID]  { return &stringPair[ID]{*id, id.String()} }
 
 // stringPair stores a value and its string representation.
 type stringPair[T comparable] struct {

internal/app/process.go

@@ -1,180 +0,0 @@
-package app
-
-import (
-	"context"
-	"errors"
-	"log"
-	"os/exec"
-	"time"
-
-	"git.gensokyo.uk/security/fortify/fst"
-	"git.gensokyo.uk/security/fortify/internal"
-	"git.gensokyo.uk/security/fortify/internal/fmsg"
-	"git.gensokyo.uk/security/fortify/internal/state"
-	"git.gensokyo.uk/security/fortify/system"
-)
-
-const shimSetupTimeout = 5 * time.Second
-
-func (seal *outcome) Run(rs *fst.RunState) error {
-	if !seal.f.CompareAndSwap(false, true) {
-		// run does much more than just starting a process; calling it twice, even if the first call fails, will result
-		// in inconsistent state that is impossible to clean up; return here to limit damage and hopefully give the
-		// other Run a chance to return
-		panic("attempted to run twice")
-	}
-
-	if rs == nil {
-		panic("invalid state")
-	}
-
-	// read comp values early to allow for early failure
-	fmsg.Verbosef("version %s", internal.Version())
-	fmsg.Verbosef("setuid helper at %s", internal.MustFsuPath())
-
-	/*
-		prepare/revert os state
-	*/
-
-	if err := seal.sys.Commit(seal.ctx); err != nil {
-		return err
-	}
-	store := state.NewMulti(seal.runDirPath)
-	deferredStoreFunc := func(c state.Cursor) error { return nil }
-	defer func() {
-		var revertErr error
-		storeErr := new(StateStoreError)
-		storeErr.Inner, storeErr.DoErr = store.Do(seal.user.aid.unwrap(), func(c state.Cursor) {
-			revertErr = func() error {
-				storeErr.InnerErr = deferredStoreFunc(c)
-
-				/*
-					revert app setup transaction
-				*/
-
-				var rt system.Enablement
-				ec := system.Process
-				if states, err := c.Load(); err != nil {
-					// revert per-process state here to limit damage
-					storeErr.OpErr = err
-					return seal.sys.Revert((*system.Criteria)(&ec))
-				} else {
-					if l := len(states); l == 0 {
-						fmsg.Verbose("no other launchers active, will clean up globals")
-						ec |= system.User
-					} else {
-						fmsg.Verbosef("found %d active launchers, cleaning up without globals", l)
-					}
-
-					// accumulate enablements of remaining launchers
-					for i, s := range states {
-						if s.Config != nil {
-							rt |= s.Config.Confinement.Enablements
-						} else {
-							log.Printf("state entry %d does not contain config", i)
-						}
-					}
-				}
-				ec |= rt ^ (system.EWayland | system.EX11 | system.EDBus | system.EPulse)
-				if fmsg.Load() {
-					if ec > 0 {
-						fmsg.Verbose("reverting operations type", system.TypeString(ec))
-					}
-				}
-
-				return seal.sys.Revert((*system.Criteria)(&ec))
-			}()
-		})
-		storeErr.save([]error{revertErr, store.Close()})
-		rs.RevertErr = storeErr.equiv("error returned during cleanup:")
-	}()
-
-	/*
-		shim process lifecycle
-	*/
-
-	waitErr := make(chan error, 1)
-	cmd := new(shimProcess)
-	if startTime, err := cmd.Start(
-		seal.user.aid.String(),
-		seal.user.supp,
-	); err != nil {
-		return err
-	} else {
-		// whether/when the fsu process was created
-		rs.Time = startTime
-	}
-
-	ctx, cancel := context.WithTimeout(seal.ctx, shimSetupTimeout)
-	defer cancel()
-
-	go func() {
-		waitErr <- cmd.Unwrap().Wait()
-		// cancel shim setup in case shim died before receiving payload
-		cancel()
-	}()
-
-	if err := cmd.Serve(ctx, &shimParams{
-		Container: seal.container,
-		Home:      seal.user.data,
-
-		Verbose: fmsg.Load(),
-	}); err != nil {
-		return err
-	}
-
-	// shim accepted setup payload, create process state
-	sd := state.State{
-		ID:   seal.id.unwrap(),
-		PID:  cmd.Unwrap().Process.Pid,
-		Time: *rs.Time,
-	}
-	var earlyStoreErr = new(StateStoreError) // returned after blocking on waitErr
-	earlyStoreErr.Inner, earlyStoreErr.DoErr = store.Do(seal.user.aid.unwrap(), func(c state.Cursor) {
-		earlyStoreErr.InnerErr = c.Save(&sd, seal.ct)
-	})
-	// destroy defunct state entry
-	deferredStoreFunc = func(c state.Cursor) error { return c.Destroy(seal.id.unwrap()) }
-
-	select {
-	case err := <-waitErr: // block until fsu/shim returns
-		if err != nil {
-			var exitError *exec.ExitError
-			if !errors.As(err, &exitError) {
-				// should be unreachable
-				rs.WaitErr = err
-			}
-
-			// store non-zero return code
-			rs.ExitCode = exitError.ExitCode()
-		} else {
-			rs.ExitCode = cmd.Unwrap().ProcessState.ExitCode()
-		}
-		if fmsg.Load() {
-			fmsg.Verbosef("process %d exited with exit code %d", cmd.Unwrap().Process.Pid, rs.ExitCode)
-		}
-
-	// this is reached when a fault makes an already running shim impossible to continue execution
-	// however a kill signal could not be delivered (should actually always happen like that since fsu)
-	// the effects of this is similar to the alternative exit path and ensures shim death
-	case err := <-cmd.Fallback():
-		rs.ExitCode = 255
-		log.Printf("cannot terminate shim on faulted setup: %v", err)
-
-	// alternative exit path relying on shim behaviour on monitor process exit
-	case <-seal.ctx.Done():
-		fmsg.Verbose("alternative exit path selected")
-	}
-
-	fmsg.Resume()
-	if seal.sync != nil {
-		if err := seal.sync.Close(); err != nil {
-			log.Printf("cannot close wayland security context: %v", err)
-		}
-	}
-	if seal.dbusMsg != nil {
-		seal.dbusMsg()
-	}
-
-	return earlyStoreErr.equiv("cannot save process state:")
-}

internal/state/multi.go

@@ -14,6 +14,7 @@ import (
 	"syscall"
 
 	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
@@ -33,10 +34,10 @@ func (s *multiStore) Do(aid int, f func(c Cursor)) (bool, error) {
 
 	// load or initialise new backend
 	b := new(multiBackend)
+	b.lock.Lock()
 	if v, ok := s.backends.LoadOrStore(aid, b); ok {
 		b = v.(*multiBackend)
 	} else {
-		b.lock.Lock()
 		b.path = path.Join(s.base, strconv.Itoa(aid))
 
 		// ensure directory
@@ -129,7 +130,7 @@ type multiBackend struct {
 	lock sync.RWMutex
 }
 
-func (b *multiBackend) filename(id *fst.ID) string {
+func (b *multiBackend) filename(id *app.ID) string {
 	return path.Join(b.path, id.String())
 }
 
@@ -189,8 +190,8 @@ func (b *multiBackend) load(decode bool) (Entries, error) {
 			return nil, fmt.Errorf("unexpected directory %q in store", e.Name())
 		}
 
-		id := new(fst.ID)
+		id := new(app.ID)
-		if err := fst.ParseAppID(id, e.Name()); err != nil {
+		if err := app.ParseAppID(id, e.Name()); err != nil {
 			return nil, err
 		}
 
@@ -335,7 +336,7 @@ func (b *multiBackend) encodeState(w io.WriteSeeker, state *State, configWriter
 	return err
 }
 
-func (b *multiBackend) Destroy(id fst.ID) error {
+func (b *multiBackend) Destroy(id app.ID) error {
 	b.lock.Lock()
 	defer b.lock.Unlock()
 

internal/state/state.go

@@ -6,11 +6,12 @@ import (
 	"time"
 
 	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
 )
 
 var ErrNoConfig = errors.New("state does not contain config")
 
-type Entries map[fst.ID]*State
+type Entries map[app.ID]*State
 
 type Store interface {
 	// Do calls f exactly once and ensures store exclusivity until f returns.
@@ -29,7 +30,7 @@ type Store interface {
 // Cursor provides access to the store
 type Cursor interface {
 	Save(state *State, configWriter io.WriterTo) error
-	Destroy(id fst.ID) error
+	Destroy(id app.ID) error
 	Load() (Entries, error)
 	Len() (int, error)
 }
@@ -37,7 +38,7 @@ type Cursor interface {
 // State is a fortify process's state
 type State struct {
 	// fortify instance id
-	ID fst.ID `json:"instance"`
+	ID app.ID `json:"instance"`
 	// child process PID value
 	PID int `json:"pid"`
 	// sealed app configuration

internal/state/state_test.go

@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/state"
 )
 
@@ -133,7 +134,7 @@ func testStore(t *testing.T, s state.Store) {
 }
 
 func makeState(t *testing.T, s *state.State, ct io.Writer) {
-	if err := fst.NewAppID(&s.ID); err != nil {
+	if err := app.NewAppID(&s.ID); err != nil {
 		t.Fatalf("cannot create dummy state: %v", err)
 	}
 	if err := gob.NewEncoder(ct).Encode(fst.Template()); err != nil {

internal/sys/interface.go

@@ -6,7 +6,7 @@ import (
 	"path"
 	"strconv"
 
-	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
@@ -41,14 +41,14 @@ type State interface {
 	Printf(format string, v ...any)
 
 	// Paths returns a populated [Paths] struct.
-	Paths() fst.Paths
+	Paths() app.Paths
 	// Uid invokes fsu and returns target uid.
 	// Any errors returned by Uid is already wrapped [fmsg.BaseError].
 	Uid(aid int) (int, error)
 }
 
-// CopyPaths is a generic implementation of [System.Paths].
+// CopyPaths is a generic implementation of [fst.Paths].
-func CopyPaths(os State, v *fst.Paths) {
+func CopyPaths(os State, v *app.Paths) {
 	v.SharePath = path.Join(os.TempDir(), "fortify."+strconv.Itoa(os.Getuid()))
 
 	fmsg.Verbosef("process share directory at %q", v.SharePath)

internal/sys/std.go

@@ -12,15 +12,15 @@ import (
 	"sync"
 	"syscall"
 
-	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/internal"
+	"git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/sandbox"
 )
 
 // Std implements System using the standard library.
 type Std struct {
-	paths     fst.Paths
+	paths     app.Paths
 	pathsOnce sync.Once
 
 	uidOnce sync.Once
@@ -48,7 +48,7 @@ func (s *Std) Printf(format string, v ...any)               { fmsg.Verbosef(form
 
 const xdgRuntimeDir = "XDG_RUNTIME_DIR"
 
-func (s *Std) Paths() fst.Paths {
+func (s *Std) Paths() app.Paths {
 	s.pathsOnce.Do(func() { CopyPaths(s, &s.paths) })
 	return s.paths
 }

main.go

@@ -20,6 +20,7 @@ import (
 	"git.gensokyo.uk/security/fortify/fst"
 	"git.gensokyo.uk/security/fortify/internal"
 	"git.gensokyo.uk/security/fortify/internal/app"
+	"git.gensokyo.uk/security/fortify/internal/app/instance"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/internal/state"
 	"git.gensokyo.uk/security/fortify/internal/sys"
@@ -73,7 +74,7 @@ func buildCommand(out io.Writer) command.Command {
 		Flag(&flagVerbose, "v", command.BoolFlag(false), "Print debug messages to the console").
 		Flag(&flagJSON, "json", command.BoolFlag(false), "Serialise output as JSON when applicable")
 
-	c.Command("shim", command.UsageInternal, func([]string) error { app.ShimMain(); return errSuccess })
+	c.Command("shim", command.UsageInternal, func([]string) error { instance.ShimMain(); return errSuccess })
 
 	c.Command("app", "Launch app defined by the specified config file", func(args []string) error {
 		if len(args) < 1 {
@@ -153,33 +154,33 @@ func buildCommand(out io.Writer) command.Command {
 				userName = passwd.Username
 			}
 
-			config.Confinement.AppID = aid
+			config.Identity = aid
-			config.Confinement.Groups = groups
+			config.Groups = groups
-			config.Confinement.Outer = homeDir
+			config.Data = homeDir
-			config.Confinement.Username = userName
+			config.Username = userName
 
 			if wayland {
-				config.Confinement.Enablements |= system.EWayland
+				config.Enablements |= system.EWayland
 			}
 			if x11 {
-				config.Confinement.Enablements |= system.EX11
+				config.Enablements |= system.EX11
 			}
 			if dBus {
-				config.Confinement.Enablements |= system.EDBus
+				config.Enablements |= system.EDBus
 			}
 			if pulse {
-				config.Confinement.Enablements |= system.EPulse
+				config.Enablements |= system.EPulse
 			}
 
 			// parse D-Bus config file from flags if applicable
 			if dBus {
 				if dbusConfigSession == "builtin" {
-					config.Confinement.SessionBus = dbus.NewConfig(fid, true, mpris)
+					config.SessionBus = dbus.NewConfig(fid, true, mpris)
 				} else {
 					if conf, err := dbus.NewConfigFromFile(dbusConfigSession); err != nil {
 						log.Fatalf("cannot load session bus proxy config from %q: %s", dbusConfigSession, err)
 					} else {
-						config.Confinement.SessionBus = conf
+						config.SessionBus = conf
 					}
 				}
 
@@ -188,14 +189,14 @@ func buildCommand(out io.Writer) command.Command {
 					if conf, err := dbus.NewConfigFromFile(dbusConfigSystem); err != nil {
 						log.Fatalf("cannot load system bus proxy config from %q: %s", dbusConfigSystem, err)
 					} else {
-						config.Confinement.SystemBus = conf
+						config.SystemBus = conf
 					}
 				}
 
 				// override log from configuration
 				if dbusVerbose {
-					config.Confinement.SessionBus.Log = true
+					config.SessionBus.Log = true
-					config.Confinement.SystemBus.Log = true
+					config.SystemBus.Log = true
 				}
 			}
 
@@ -239,11 +240,11 @@ func buildCommand(out io.Writer) command.Command {
 
 		case 1: // instance
 			name := args[0]
-			config, instance := tryShort(name)
+			config, entry := tryShort(name)
 			if config == nil {
 				config = tryPath(name)
 			}
-			printShowInstance(os.Stdout, time.Now().UTC(), instance, config, showFlagShort, flagJSON)
+			printShowInstance(os.Stdout, time.Now().UTC(), entry, config, showFlagShort, flagJSON)
 
 		default:
 			log.Fatal("show requires 1 argument")
@@ -284,15 +285,15 @@ func runApp(config *fst.Config) {
 	ctx, stop := signal.NotifyContext(context.Background(),
 		syscall.SIGINT, syscall.SIGTERM)
 	defer stop() // unreachable
-	a := app.MustNew(ctx, std)
+	a := instance.MustNew(instance.ISetuid, ctx, std)
 
-	rs := new(fst.RunState)
+	rs := new(app.RunState)
 	if sa, err := a.Seal(config); err != nil {
 		fmsg.PrintBaseError(err, "cannot seal app:")
-		rs.ExitCode = 1
+		internal.Exit(1)
 	} else {
-		// this updates ExitCode
+		internal.Exit(instance.PrintRunStateErr(instance.ISetuid, rs, sa.Run(rs)))
-		app.PrintRunStateErr(rs, sa.Run(rs))
 	}
-	internal.Exit(rs.ExitCode)
+
+	*(*int)(nil) = 0 // not reached
 }

nixos.nix

@@ -88,94 +88,101 @@ in
 
                   conf = {
                     inherit (app) id;
-                    path = pkgs.writeScript "${app.name}-start" ''
-                      #!${pkgs.zsh}${pkgs.zsh.shellPath}
-                      ${script}
-                    '';
-                    args = [ "${app.name}-start" ];
 
-                    confinement = {
+                    path =
-                      app_id = aid;
+                      if app.path == null then
-                      inherit (app) groups;
+                        pkgs.writeScript "${app.name}-start" ''
-                      username = getsubname fid aid;
+                          #!${pkgs.zsh}${pkgs.zsh.shellPath}
-                      home = getsubhome fid aid;
+                          ${script}
-                      sandbox = {
+                        ''
-                        inherit (app)
+                      else
-                          devel
+                        app.path;
-                          userns
+                    args = if app.args == null then [ "${app.name}-start" ] else app.args;
-                          net
-                          dev
-                          tty
-                          multiarch
-                          env
-                          ;
-                        map_real_uid = app.mapRealUid;
-                        direct_wayland = app.insecureWayland;
 
-                        filesystem =
+                    inherit enablements;
-                          let
+
-                            bind = src: { inherit src; };
+                    inherit (dbusConfig) session_bus system_bus;
-                            mustBind = src: {
+                    direct_wayland = app.insecureWayland;
-                              inherit src;
+
-                              require = true;
+                    username = getsubname fid aid;
-                            };
+                    data = getsubhome fid aid;
-                            devBind = src: {
+
-                              inherit src;
+                    identity = aid;
-                              dev = true;
+                    inherit (app) groups;
-                            };
+
-                          in
+                    container = {
+                      inherit (app)
+                        devel
+                        userns
+                        net
+                        device
+                        tty
+                        multiarch
+                        env
+                        ;
+                      map_real_uid = app.mapRealUid;
+
+                      filesystem =
+                        let
+                          bind = src: { inherit src; };
+                          mustBind = src: {
+                            inherit src;
+                            require = true;
+                          };
+                          devBind = src: {
+                            inherit src;
+                            dev = true;
+                          };
+                        in
+                        [
+                          (mustBind "/bin")
+                          (mustBind "/usr/bin")
+                          (mustBind "/nix/store")
+                          (bind "/sys/block")
+                          (bind "/sys/bus")
+                          (bind "/sys/class")
+                          (bind "/sys/dev")
+                          (bind "/sys/devices")
+                        ]
+                        ++ optionals app.nix [
+                          (mustBind "/nix/var")
+                          (bind "/var/db/nix-channels")
+                        ]
+                        ++ optionals isGraphical [
+                          (devBind "/dev/dri")
+                          (devBind "/dev/nvidiactl")
+                          (devBind "/dev/nvidia-modeset")
+                          (devBind "/dev/nvidia-uvm")
+                          (devBind "/dev/nvidia-uvm-tools")
+                          (devBind "/dev/nvidia0")
+                        ]
+                        ++ app.extraPaths;
+                      auto_etc = true;
+                      cover = [ "/var/run/nscd" ];
+
+                      symlink =
+                        [
                           [
-                            (mustBind "/bin")
+                            "*/run/current-system"
-                            (mustBind "/usr/bin")
+                            "/run/current-system"
-                            (mustBind "/nix/store")
-                            (bind "/sys/block")
-                            (bind "/sys/bus")
-                            (bind "/sys/class")
-                            (bind "/sys/dev")
-                            (bind "/sys/devices")
                           ]
-                          ++ optionals app.nix [
+                        ]
-                            (mustBind "/nix/var")
+                        ++ optionals (isGraphical && config.hardware.graphics.enable) (
-                            (bind "/var/db/nix-channels")
-                          ]
-                          ++ optionals isGraphical [
-                            (devBind "/dev/dri")
-                            (devBind "/dev/nvidiactl")
-                            (devBind "/dev/nvidia-modeset")
-                            (devBind "/dev/nvidia-uvm")
-                            (devBind "/dev/nvidia-uvm-tools")
-                            (devBind "/dev/nvidia0")
-                          ]
-                          ++ app.extraPaths;
-                        auto_etc = true;
-                        cover = [ "/var/run/nscd" ];
-
-                        symlink =
                           [
                             [
-                              "*/run/current-system"
+                              config.systemd.tmpfiles.settings.graphics-driver."/run/opengl-driver"."L+".argument
-                              "/run/current-system"
+                              "/run/opengl-driver"
                             ]
                           ]
-                          ++ optionals (isGraphical && config.hardware.graphics.enable) (
+                          ++ optionals (app.multiarch && config.hardware.graphics.enable32Bit) [
                             [
-                              [
+                              config.systemd.tmpfiles.settings.graphics-driver."/run/opengl-driver-32"."L+".argument
-                                config.systemd.tmpfiles.settings.graphics-driver."/run/opengl-driver"."L+".argument
+                              /run/opengl-driver-32
-                                "/run/opengl-driver"
-                              ]
                             ]
-                            ++ optionals (app.multiarch && config.hardware.graphics.enable32Bit) [
+                          ]
-                              [
+                        );
-                                config.systemd.tmpfiles.settings.graphics-driver."/run/opengl-driver-32"."L+".argument
-                                /run/opengl-driver-32
-                              ]
-                            ]
-                          );
-                      };
-
-                      inherit enablements;
-                      inherit (dbusConfig) session_bus system_bus;
                     };
+
                   };
                 in
                 pkgs.writeShellScriptBin app.name ''
@@ -197,9 +204,11 @@ in
                   ${copy "${pkg}/share/icons"}
                   ${copy "${pkg}/share/man"}
 
-                  substituteInPlace $out/share/applications/* \
+                  if test -d "$out/share/applications"; then
-                    --replace-warn '${pkg}/bin/' "" \
+                    substituteInPlace $out/share/applications/* \
-                    --replace-warn '${pkg}/libexec/' ""
+                      --replace-warn '${pkg}/bin/' "" \
+                      --replace-warn '${pkg}/libexec/' ""
+                  fi
                 ''
               )
               ++ acc

options.md

@@ -35,7 +35,7 @@ package
 
 
 *Default:*
-` <derivation fortify-static-x86_64-unknown-linux-musl-0.3.0> `
+` <derivation fortify-static-x86_64-unknown-linux-musl-0.4.0> `
 
 
 
@@ -73,6 +73,25 @@ list of package
 
 
 
+## environment\.fortify\.apps\.\*\.args
+
+
+
+Custom args\.
+Setting this to null will default to script name\.
+
+
+
+*Type:*
+null or (list of string)
+
+
+
+*Default:*
+` null `
+
+
+
 ## environment\.fortify\.apps\.\*\.capability\.dbus
 
 
@@ -203,11 +222,11 @@ null or anything
 
 
 
-## environment\.fortify\.apps\.\*\.dev
+## environment\.fortify\.apps\.\*\.devel
 
 
 
-Whether to enable access to all devices\.
+Whether to enable debugging-related kernel interfaces\.
 
 
 
@@ -226,11 +245,11 @@ boolean
 
 
 
-## environment\.fortify\.apps\.\*\.devel
+## environment\.fortify\.apps\.\*\.device
 
 
 
-Whether to enable debugging-related kernel interfaces\.
+Whether to enable access to all devices\.
 
 
 
@@ -486,6 +505,25 @@ boolean
 
 
 
+## environment\.fortify\.apps\.\*\.path
+
+
+
+Custom executable path\.
+Setting this to null will default to the start script\.
+
+
+
+*Type:*
+null or string
+
+
+
+*Default:*
+` null `
+
+
+
 ## environment\.fortify\.apps\.\*\.script
 
 
@@ -606,7 +644,7 @@ package
 
 
 *Default:*
-` <derivation fortify-fsu-0.3.0> `
+` <derivation fortify-fsu-0.4.0> `
 
 
 

options.nix

@@ -94,6 +94,24 @@ in
                 '';
               };
 
+              path = mkOption {
+                type = nullOr str;
+                default = null;
+                description = ''
+                  Custom executable path.
+                  Setting this to null will default to the start script.
+                '';
+              };
+
+              args = mkOption {
+                type = nullOr (listOf str);
+                default = null;
+                description = ''
+                  Custom args.
+                  Setting this to null will default to script name.
+                '';
+              };
+
               script = mkOption {
                 type = nullOr str;
                 default = null;
@@ -159,7 +177,7 @@ in
 
               nix = mkEnableOption "nix daemon access";
               mapRealUid = mkEnableOption "mapping to priv-user uid";
-              dev = mkEnableOption "access to all devices";
+              device = mkEnableOption "access to all devices";
               insecureWayland = mkEnableOption "direct access to the Wayland socket";
 
               gpu = mkOption {

package.nix

@@ -31,7 +31,7 @@
 
 buildGoModule rec {
   pname = "fortify";
-  version = "0.3.0";
+  version = "0.4.0";
 
   src = builtins.path {
     name = "${pname}-src";

parse.go

@@ -67,7 +67,7 @@ func tryFd(name string) io.ReadCloser {
 	}
 }
 
-func tryShort(name string) (config *fst.Config, instance *state.State) {
+func tryShort(name string) (config *fst.Config, entry *state.State) {
 	likePrefix := false
 	if len(name) <= 32 {
 		likePrefix = true
@@ -96,8 +96,8 @@ func tryShort(name string) (config *fst.Config, instance *state.State) {
 				v := id.String()
 				if strings.HasPrefix(v, name) {
 					// match, use config from this state entry
-					instance = entries[id]
+					entry = entries[id]
-					config = instance.Config
+					config = entry.Config
 					break
 				}
 

print.go

@@ -56,7 +56,7 @@ func printShowInstance(
 	t := newPrinter(output)
 	defer t.MustFlush()
 
-	if config.Confinement.Sandbox == nil {
+	if config.Container == nil {
 		mustPrint(output, "Warning: this configuration uses permissive defaults!\n\n")
 	}
 
@@ -69,19 +69,21 @@ func printShowInstance(
 
 	t.Printf("App\n")
 	if config.ID != "" {
-		t.Printf(" ID:\t%d (%s)\n", config.Confinement.AppID, config.ID)
+		t.Printf(" ID:\t%d (%s)\n", config.Identity, config.ID)
 	} else {
-		t.Printf(" ID:\t%d\n", config.Confinement.AppID)
+		t.Printf(" ID:\t%d\n", config.Identity)
 	}
-	t.Printf(" Enablements:\t%s\n", config.Confinement.Enablements.String())
+	t.Printf(" Enablements:\t%s\n", config.Enablements.String())
-	if len(config.Confinement.Groups) > 0 {
+	if len(config.Groups) > 0 {
-		t.Printf(" Groups:\t%q\n", config.Confinement.Groups)
+		t.Printf(" Groups:\t%s\n", strings.Join(config.Groups, ", "))
 	}
-	t.Printf(" Directory:\t%s\n", config.Confinement.Outer)
+	if config.Data != "" {
-	if config.Confinement.Sandbox != nil {
+		t.Printf(" Data:\t%s\n", config.Data)
-		sandbox := config.Confinement.Sandbox
+	}
-		if sandbox.Hostname != "" {
+	if config.Container != nil {
-			t.Printf(" Hostname:\t%q\n", sandbox.Hostname)
+		container := config.Container
+		if container.Hostname != "" {
+			t.Printf(" Hostname:\t%s\n", container.Hostname)
 		}
 		flags := make([]string, 0, 7)
 		writeFlag := func(name string, value bool) {
@@ -89,38 +91,40 @@ func printShowInstance(
 				flags = append(flags, name)
 			}
 		}
-		writeFlag("userns", sandbox.Userns)
+		writeFlag("userns", container.Userns)
-		writeFlag("net", sandbox.Net)
+		writeFlag("devel", container.Devel)
-		writeFlag("dev", sandbox.Dev)
+		writeFlag("net", container.Net)
-		writeFlag("tty", sandbox.Tty)
+		writeFlag("device", container.Device)
-		writeFlag("mapuid", sandbox.MapRealUID)
+		writeFlag("tty", container.Tty)
-		writeFlag("directwl", sandbox.DirectWayland)
+		writeFlag("mapuid", container.MapRealUID)
-		writeFlag("autoetc", sandbox.AutoEtc)
+		writeFlag("directwl", config.DirectWayland)
+		writeFlag("autoetc", container.AutoEtc)
 		if len(flags) == 0 {
 			flags = append(flags, "none")
 		}
 		t.Printf(" Flags:\t%s\n", strings.Join(flags, " "))
 
-		etc := sandbox.Etc
+		etc := container.Etc
 		if etc == "" {
 			etc = "/etc"
 		}
 		t.Printf(" Etc:\t%s\n", etc)
 
-		if len(sandbox.Cover) > 0 {
+		if len(container.Cover) > 0 {
-			t.Printf(" Cover:\t%s\n", strings.Join(sandbox.Cover, " "))
+			t.Printf(" Cover:\t%s\n", strings.Join(container.Cover, " "))
 		}
 
-		// Env           map[string]string   `json:"env"`
+		t.Printf(" Path:\t%s\n", config.Path)
-		// Link          [][2]string         `json:"symlink"`
+	}
+	if len(config.Args) > 0 {
+		t.Printf(" Arguments:\t%s\n", strings.Join(config.Args, " "))
 	}
-	t.Printf(" Command:\t%s\n", strings.Join(config.Args, " "))
 	t.Printf("\n")
 
 	if !short {
-		if config.Confinement.Sandbox != nil && len(config.Confinement.Sandbox.Filesystem) > 0 {
+		if config.Container != nil && len(config.Container.Filesystem) > 0 {
 			t.Printf("Filesystem\n")
-			for _, f := range config.Confinement.Sandbox.Filesystem {
+			for _, f := range config.Container.Filesystem {
 				if f == nil {
 					continue
 				}
@@ -148,9 +152,9 @@ func printShowInstance(
 			}
 			t.Printf("\n")
 		}
-		if len(config.Confinement.ExtraPerms) > 0 {
+		if len(config.ExtraPerms) > 0 {
 			t.Printf("Extra ACL\n")
-			for _, p := range config.Confinement.ExtraPerms {
+			for _, p := range config.ExtraPerms {
 				if p == nil {
 					continue
 				}
@@ -178,14 +182,14 @@ func printShowInstance(
 			t.Printf(" Broadcast:\t%q\n", c.Broadcast)
 		}
 	}
-	if config.Confinement.SessionBus != nil {
+	if config.SessionBus != nil {
 		t.Printf("Session bus\n")
-		printDBus(config.Confinement.SessionBus)
+		printDBus(config.SessionBus)
 		t.Printf("\n")
 	}
-	if config.Confinement.SystemBus != nil {
+	if config.SystemBus != nil {
 		t.Printf("System bus\n")
-		printDBus(config.Confinement.SystemBus)
+		printDBus(config.SystemBus)
 		t.Printf("\n")
 	}
 }
@@ -247,22 +251,26 @@ func printPs(output io.Writer, now time.Time, s state.Store, short, flagJSON boo
 	t := newPrinter(output)
 	defer t.MustFlush()
 
-	t.Println("\tInstance\tPID\tApp\tUptime\tEnablements\tCommand")
+	t.Println("\tInstance\tPID\tApplication\tUptime")
 	for _, e := range exp {
-		var (
+		if len(e.s) != 1<<5 {
-			es = "(No confinement information)"
+			// unreachable
-			cs = "(No command information)"
+			log.Printf("possible store corruption: invalid instance string %s", e.s)
-			as = "(No configuration information)"
+			continue
-		)
-		if e.Config != nil {
-			es = e.Config.Confinement.Enablements.String()
-			cs = fmt.Sprintf("%q", e.Config.Args)
-			as = strconv.Itoa(e.Config.Confinement.AppID)
 		}
-		t.Printf("\t%s\t%d\t%s\t%s\t%s\t%s\n",
+
-			e.s[:8], e.PID, as, now.Sub(e.Time).Round(time.Second).String(), strings.TrimPrefix(es, ", "), cs)
+		as := "(No configuration information)"
+		if e.Config != nil {
+			as = strconv.Itoa(e.Config.Identity)
+			id := e.Config.ID
+			if id == "" {
+				id = "uk.gensokyo.fortify." + e.s[:8]
+			}
+			as += " (" + id + ")"
+		}
+		t.Printf("\t%s\t%d\t%s\t%s\n",
+			e.s[:8], e.PID, as, now.Sub(e.Time).Round(time.Second).String())
 	}
-	t.Println()
 }
 
 type expandedStateEntry struct {

print_test.go

@@ -7,11 +7,12 @@ import (
 
 	"git.gensokyo.uk/security/fortify/dbus"
 	"git.gensokyo.uk/security/fortify/fst"
+	"git.gensokyo.uk/security/fortify/internal/app"
 	"git.gensokyo.uk/security/fortify/internal/state"
 )
 
 var (
-	testID = fst.ID{
+	testID = app.ID{
 		0x8e, 0x2c, 0x76, 0xb0,
 		0x66, 0xda, 0xbe, 0x57,
 		0x4c, 0xf0, 0x73, 0xbd,
@@ -38,13 +39,14 @@ func Test_printShowInstance(t *testing.T) {
 		{"config", nil, fst.Template(), false, false, `App
  ID:             9 (org.chromium.Chromium)
  Enablements:    wayland, dbus, pulseaudio
- Groups:         ["video"]
+ Groups:         video, dialout, plugdev
- Directory:      /var/lib/persist/home/org.chromium.Chromium
+ Data:           /var/lib/fortify/u0/org.chromium.Chromium
- Hostname:       "localhost"
+ Hostname:       localhost
- Flags:          userns net dev tty mapuid autoetc
+ Flags:          userns devel net device tty mapuid autoetc
  Etc:            /etc
  Cover:          /var/run/nscd
- Command:        chromium --ignore-gpu-blocklist --disable-smooth-scrolling --enable-features=UseOzonePlatform --ozone-platform=wayland
+ Path:           /run/current-system/sw/bin/chromium
+ Arguments:      chromium --ignore-gpu-blocklist --disable-smooth-scrolling --enable-features=UseOzonePlatform --ozone-platform=wayland
 
 Filesystem
  +/nix/store
@@ -75,39 +77,33 @@ System bus
 App
  ID:             0
  Enablements:    (no enablements)
- Directory:      
- Command:        
 
 `},
-		{"config flag none", nil, &fst.Config{Confinement: fst.ConfinementConfig{Sandbox: new(fst.SandboxConfig)}}, false, false, `App
+		{"config flag none", nil, &fst.Config{Container: new(fst.ContainerConfig)}, false, false, `App
  ID:             0
  Enablements:    (no enablements)
- Directory:      
  Flags:          none
  Etc:            /etc
- Command:        
+ Path:           
 
 `},
-		{"config nil entries", nil, &fst.Config{Confinement: fst.ConfinementConfig{Sandbox: &fst.SandboxConfig{Filesystem: make([]*fst.FilesystemConfig, 1)}, ExtraPerms: make([]*fst.ExtraPermConfig, 1)}}, false, false, `App
+		{"config nil entries", nil, &fst.Config{Container: &fst.ContainerConfig{Filesystem: make([]*fst.FilesystemConfig, 1)}, ExtraPerms: make([]*fst.ExtraPermConfig, 1)}, false, false, `App
  ID:             0
  Enablements:    (no enablements)
- Directory:      
  Flags:          none
  Etc:            /etc
- Command:        
+ Path:           
 
 Filesystem
 
 Extra ACL
 
 `},
-		{"config pd dbus see", nil, &fst.Config{Confinement: fst.ConfinementConfig{SessionBus: &dbus.Config{See: []string{"org.example.test"}}}}, false, false, `Warning: this configuration uses permissive defaults!
+		{"config pd dbus see", nil, &fst.Config{SessionBus: &dbus.Config{See: []string{"org.example.test"}}}, false, false, `Warning: this configuration uses permissive defaults!
 
 App
  ID:             0
  Enablements:    (no enablements)
- Directory:      
- Command:        
 
 Session bus
  Filter:    false
@@ -122,13 +118,14 @@ Session bus
 App
  ID:             9 (org.chromium.Chromium)
  Enablements:    wayland, dbus, pulseaudio
- Groups:         ["video"]
+ Groups:         video, dialout, plugdev
- Directory:      /var/lib/persist/home/org.chromium.Chromium
+ Data:           /var/lib/fortify/u0/org.chromium.Chromium
- Hostname:       "localhost"
+ Hostname:       localhost
- Flags:          userns net dev tty mapuid autoetc
+ Flags:          userns devel net device tty mapuid autoetc
  Etc:            /etc
  Cover:          /var/run/nscd
- Command:        chromium --ignore-gpu-blocklist --disable-smooth-scrolling --enable-features=UseOzonePlatform --ozone-platform=wayland
+ Path:           /run/current-system/sw/bin/chromium
+ Arguments:      chromium --ignore-gpu-blocklist --disable-smooth-scrolling --enable-features=UseOzonePlatform --ozone-platform=wayland
 
 Filesystem
  +/nix/store
@@ -163,8 +160,6 @@ State
 App
  ID:             0
  Enablements:    (no enablements)
- Directory:      
- Command:        
 
 `},
 
@@ -200,139 +195,67 @@ App
       "--enable-features=UseOzonePlatform",
       "--ozone-platform=wayland"
     ],
-    "confinement": {
+    "enablements": 13,
-      "app_id": 9,
+    "session_bus": {
-      "groups": [
+      "see": null,
-        "video"
+      "talk": [
+        "org.freedesktop.Notifications",
+        "org.freedesktop.FileManager1",
+        "org.freedesktop.ScreenSaver",
+        "org.freedesktop.secrets",
+        "org.kde.kwalletd5",
+        "org.kde.kwalletd6",
+        "org.gnome.SessionManager"
       ],
-      "username": "chronos",
+      "own": [
-      "home_inner": "/var/lib/fortify",
+        "org.chromium.Chromium.*",
-      "home": "/var/lib/persist/home/org.chromium.Chromium",
+        "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-      "sandbox": {
+        "org.mpris.MediaPlayer2.chromium.*"
-        "hostname": "localhost",
-        "seccomp": 32,
-        "devel": true,
-        "userns": true,
-        "net": true,
-        "tty": true,
-        "multiarch": true,
-        "env": {
-          "GOOGLE_API_KEY": "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
-          "GOOGLE_DEFAULT_CLIENT_ID": "77185425430.apps.googleusercontent.com",
-          "GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT"
-        },
-        "map_real_uid": true,
-        "dev": true,
-        "filesystem": [
-          {
-            "src": "/nix/store"
-          },
-          {
-            "src": "/run/current-system"
-          },
-          {
-            "src": "/run/opengl-driver"
-          },
-          {
-            "src": "/var/db/nix-channels"
-          },
-          {
-            "dst": "/data/data/org.chromium.Chromium",
-            "src": "/var/lib/fortify/u0/org.chromium.Chromium",
-            "write": true,
-            "require": true
-          },
-          {
-            "src": "/dev/dri",
-            "dev": true
-          }
-        ],
-        "symlink": [
-          [
-            "/run/user/65534",
-            "/run/user/150"
-          ]
-        ],
-        "etc": "/etc",
-        "auto_etc": true,
-        "cover": [
-          "/var/run/nscd"
-        ]
-      },
-      "extra_perms": [
-        {
-          "ensure": true,
-          "path": "/var/lib/fortify/u0",
-          "x": true
-        },
-        {
-          "path": "/var/lib/fortify/u0/org.chromium.Chromium",
-          "r": true,
-          "w": true,
-          "x": true
-        }
       ],
-      "system_bus": {
+      "call": {
-        "see": null,
+        "org.freedesktop.portal.*": "*"
-        "talk": [
-          "org.bluez",
-          "org.freedesktop.Avahi",
-          "org.freedesktop.UPower"
-        ],
-        "own": null,
-        "call": null,
-        "broadcast": null,
-        "filter": true
       },
-      "session_bus": {
+      "broadcast": {
-        "see": null,
+        "org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
-        "talk": [
-          "org.freedesktop.Notifications",
-          "org.freedesktop.FileManager1",
-          "org.freedesktop.ScreenSaver",
-          "org.freedesktop.secrets",
-          "org.kde.kwalletd5",
-          "org.kde.kwalletd6",
-          "org.gnome.SessionManager"
-        ],
-        "own": [
-          "org.chromium.Chromium.*",
-          "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-          "org.mpris.MediaPlayer2.chromium.*"
-        ],
-        "call": {
-          "org.freedesktop.portal.*": "*"
-        },
-        "broadcast": {
-          "org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
-        },
-        "filter": true
       },
-      "enablements": 13
+      "filter": true
-    }
+    },
-  },
+    "system_bus": {
-  "time": "1970-01-01T00:00:00.000000009Z"
+      "see": null,
-}
+      "talk": [
-`},
+        "org.bluez",
-		{"json config", nil, fst.Template(), false, true, `{
+        "org.freedesktop.Avahi",
-  "id": "org.chromium.Chromium",
+        "org.freedesktop.UPower"
-  "path": "/run/current-system/sw/bin/chromium",
+      ],
-  "args": [
+      "own": null,
-    "chromium",
+      "call": null,
-    "--ignore-gpu-blocklist",
+      "broadcast": null,
-    "--disable-smooth-scrolling",
+      "filter": true
-    "--enable-features=UseOzonePlatform",
+    },
-    "--ozone-platform=wayland"
-  ],
-  "confinement": {
-    "app_id": 9,
-    "groups": [
-      "video"
-    ],
     "username": "chronos",
-    "home_inner": "/var/lib/fortify",
+    "shell": "/run/current-system/sw/bin/zsh",
-    "home": "/var/lib/persist/home/org.chromium.Chromium",
+    "data": "/var/lib/fortify/u0/org.chromium.Chromium",
-    "sandbox": {
+    "dir": "/data/data/org.chromium.Chromium",
+    "extra_perms": [
+      {
+        "ensure": true,
+        "path": "/var/lib/fortify/u0",
+        "x": true
+      },
+      {
+        "path": "/var/lib/fortify/u0/org.chromium.Chromium",
+        "r": true,
+        "w": true,
+        "x": true
+      }
+    ],
+    "identity": 9,
+    "groups": [
+      "video",
+      "dialout",
+      "plugdev"
+    ],
+    "container": {
       "hostname": "localhost",
       "seccomp": 32,
       "devel": true,
@@ -346,7 +269,7 @@ App
         "GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT"
       },
       "map_real_uid": true,
-      "dev": true,
+      "device": true,
       "filesystem": [
         {
           "src": "/nix/store"
@@ -382,57 +305,131 @@ App
       "cover": [
         "/var/run/nscd"
       ]
+    }
+  },
+  "time": "1970-01-01T00:00:00.000000009Z"
+}
+`},
+		{"json config", nil, fst.Template(), false, true, `{
+  "id": "org.chromium.Chromium",
+  "path": "/run/current-system/sw/bin/chromium",
+  "args": [
+    "chromium",
+    "--ignore-gpu-blocklist",
+    "--disable-smooth-scrolling",
+    "--enable-features=UseOzonePlatform",
+    "--ozone-platform=wayland"
+  ],
+  "enablements": 13,
+  "session_bus": {
+    "see": null,
+    "talk": [
+      "org.freedesktop.Notifications",
+      "org.freedesktop.FileManager1",
+      "org.freedesktop.ScreenSaver",
+      "org.freedesktop.secrets",
+      "org.kde.kwalletd5",
+      "org.kde.kwalletd6",
+      "org.gnome.SessionManager"
+    ],
+    "own": [
+      "org.chromium.Chromium.*",
+      "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
+      "org.mpris.MediaPlayer2.chromium.*"
+    ],
+    "call": {
+      "org.freedesktop.portal.*": "*"
     },
-    "extra_perms": [
+    "broadcast": {
+      "org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
+    },
+    "filter": true
+  },
+  "system_bus": {
+    "see": null,
+    "talk": [
+      "org.bluez",
+      "org.freedesktop.Avahi",
+      "org.freedesktop.UPower"
+    ],
+    "own": null,
+    "call": null,
+    "broadcast": null,
+    "filter": true
+  },
+  "username": "chronos",
+  "shell": "/run/current-system/sw/bin/zsh",
+  "data": "/var/lib/fortify/u0/org.chromium.Chromium",
+  "dir": "/data/data/org.chromium.Chromium",
+  "extra_perms": [
+    {
+      "ensure": true,
+      "path": "/var/lib/fortify/u0",
+      "x": true
+    },
+    {
+      "path": "/var/lib/fortify/u0/org.chromium.Chromium",
+      "r": true,
+      "w": true,
+      "x": true
+    }
+  ],
+  "identity": 9,
+  "groups": [
+    "video",
+    "dialout",
+    "plugdev"
+  ],
+  "container": {
+    "hostname": "localhost",
+    "seccomp": 32,
+    "devel": true,
+    "userns": true,
+    "net": true,
+    "tty": true,
+    "multiarch": true,
+    "env": {
+      "GOOGLE_API_KEY": "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
+      "GOOGLE_DEFAULT_CLIENT_ID": "77185425430.apps.googleusercontent.com",
+      "GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT"
+    },
+    "map_real_uid": true,
+    "device": true,
+    "filesystem": [
       {
-        "ensure": true,
+        "src": "/nix/store"
-        "path": "/var/lib/fortify/u0",
-        "x": true
       },
       {
-        "path": "/var/lib/fortify/u0/org.chromium.Chromium",
+        "src": "/run/current-system"
-        "r": true,
+      },
-        "w": true,
+      {
-        "x": true
+        "src": "/run/opengl-driver"
+      },
+      {
+        "src": "/var/db/nix-channels"
+      },
+      {
+        "dst": "/data/data/org.chromium.Chromium",
+        "src": "/var/lib/fortify/u0/org.chromium.Chromium",
+        "write": true,
+        "require": true
+      },
+      {
+        "src": "/dev/dri",
+        "dev": true
       }
     ],
-    "system_bus": {
+    "symlink": [
-      "see": null,
+      [
-      "talk": [
+        "/run/user/65534",
-        "org.bluez",
+        "/run/user/150"
-        "org.freedesktop.Avahi",
+      ]
-        "org.freedesktop.UPower"
+    ],
-      ],
+    "etc": "/etc",
-      "own": null,
+    "auto_etc": true,
-      "call": null,
+    "cover": [
-      "broadcast": null,
+      "/var/run/nscd"
-      "filter": true
+    ]
-    },
-    "session_bus": {
-      "see": null,
-      "talk": [
-        "org.freedesktop.Notifications",
-        "org.freedesktop.FileManager1",
-        "org.freedesktop.ScreenSaver",
-        "org.freedesktop.secrets",
-        "org.kde.kwalletd5",
-        "org.kde.kwalletd6",
-        "org.gnome.SessionManager"
-      ],
-      "own": [
-        "org.chromium.Chromium.*",
-        "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-        "org.mpris.MediaPlayer2.chromium.*"
-      ],
-      "call": {
-        "org.freedesktop.portal.*": "*"
-      },
-      "broadcast": {
-        "org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
-      },
-      "filter": true
-    },
-    "enablements": 13
   }
 }
 `},
@@ -458,23 +455,19 @@ func Test_printPs(t *testing.T) {
 		short, json bool
 		want        string
 	}{
-		{"no entries", make(state.Entries), false, false, `    Instance    PID    App    Uptime    Enablements    Command
+		{"no entries", make(state.Entries), false, false, "    Instance    PID    Application    Uptime\n"},
-
+		{"no entries short", make(state.Entries), true, false, ""},
-`},
+		{"nil instance", state.Entries{testID: nil}, false, false, "    Instance    PID    Application    Uptime\n"},
-		{"no entries short", make(state.Entries), true, false, ``},
+		{"state corruption", state.Entries{app.ID{}: testState}, false, false, "    Instance    PID    Application    Uptime\n"},
-		{"nil instance", state.Entries{testID: nil}, false, false, `    Instance    PID    App    Uptime    Enablements    Command
-
-`},
-		{"state corruption", state.Entries{fst.ID{}: testState}, false, false, `    Instance    PID    App    Uptime    Enablements    Command
 
+		{"valid pd", state.Entries{testID: &state.State{ID: testID, PID: 1 << 8, Config: new(fst.Config), Time: testAppTime}}, false, false, `    Instance    PID    Application                         Uptime
+    8e2c76b0    256    0 (uk.gensokyo.fortify.8e2c76b0)    1h2m32s
 `},
 
-		{"valid", state.Entries{testID: testState}, false, false, `    Instance    PID           App    Uptime     Enablements                  Command
+		{"valid", state.Entries{testID: testState}, false, false, `    Instance    PID           Application                  Uptime
-    8e2c76b0    3735928559    9      1h2m32s    wayland, dbus, pulseaudio    ["chromium" "--ignore-gpu-blocklist" "--disable-smooth-scrolling" "--enable-features=UseOzonePlatform" "--ozone-platform=wayland"]
+    8e2c76b0    3735928559    9 (org.chromium.Chromium)    1h2m32s
-
-`},
-		{"valid short", state.Entries{testID: testState}, true, false, `8e2c76b0
 `},
+		{"valid short", state.Entries{testID: testState}, true, false, "8e2c76b0\n"},
 		{"valid json", state.Entries{testID: testState}, false, true, `{
   "8e2c76b066dabe574cf073bdb46eb5c1": {
     "instance": [
@@ -506,115 +499,116 @@ func Test_printPs(t *testing.T) {
         "--enable-features=UseOzonePlatform",
         "--ozone-platform=wayland"
       ],
-      "confinement": {
+      "enablements": 13,
-        "app_id": 9,
+      "session_bus": {
-        "groups": [
+        "see": null,
-          "video"
+        "talk": [
+          "org.freedesktop.Notifications",
+          "org.freedesktop.FileManager1",
+          "org.freedesktop.ScreenSaver",
+          "org.freedesktop.secrets",
+          "org.kde.kwalletd5",
+          "org.kde.kwalletd6",
+          "org.gnome.SessionManager"
         ],
-        "username": "chronos",
+        "own": [
-        "home_inner": "/var/lib/fortify",
+          "org.chromium.Chromium.*",
-        "home": "/var/lib/persist/home/org.chromium.Chromium",
+          "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-        "sandbox": {
+          "org.mpris.MediaPlayer2.chromium.*"
-          "hostname": "localhost",
+        ],
-          "seccomp": 32,
+        "call": {
-          "devel": true,
+          "org.freedesktop.portal.*": "*"
-          "userns": true,
-          "net": true,
-          "tty": true,
-          "multiarch": true,
-          "env": {
-            "GOOGLE_API_KEY": "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
-            "GOOGLE_DEFAULT_CLIENT_ID": "77185425430.apps.googleusercontent.com",
-            "GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT"
-          },
-          "map_real_uid": true,
-          "dev": true,
-          "filesystem": [
-            {
-              "src": "/nix/store"
-            },
-            {
-              "src": "/run/current-system"
-            },
-            {
-              "src": "/run/opengl-driver"
-            },
-            {
-              "src": "/var/db/nix-channels"
-            },
-            {
-              "dst": "/data/data/org.chromium.Chromium",
-              "src": "/var/lib/fortify/u0/org.chromium.Chromium",
-              "write": true,
-              "require": true
-            },
-            {
-              "src": "/dev/dri",
-              "dev": true
-            }
-          ],
-          "symlink": [
-            [
-              "/run/user/65534",
-              "/run/user/150"
-            ]
-          ],
-          "etc": "/etc",
-          "auto_etc": true,
-          "cover": [
-            "/var/run/nscd"
-          ]
         },
-        "extra_perms": [
+        "broadcast": {
+          "org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
+        },
+        "filter": true
+      },
+      "system_bus": {
+        "see": null,
+        "talk": [
+          "org.bluez",
+          "org.freedesktop.Avahi",
+          "org.freedesktop.UPower"
+        ],
+        "own": null,
+        "call": null,
+        "broadcast": null,
+        "filter": true
+      },
+      "username": "chronos",
+      "shell": "/run/current-system/sw/bin/zsh",
+      "data": "/var/lib/fortify/u0/org.chromium.Chromium",
+      "dir": "/data/data/org.chromium.Chromium",
+      "extra_perms": [
+        {
+          "ensure": true,
+          "path": "/var/lib/fortify/u0",
+          "x": true
+        },
+        {
+          "path": "/var/lib/fortify/u0/org.chromium.Chromium",
+          "r": true,
+          "w": true,
+          "x": true
+        }
+      ],
+      "identity": 9,
+      "groups": [
+        "video",
+        "dialout",
+        "plugdev"
+      ],
+      "container": {
+        "hostname": "localhost",
+        "seccomp": 32,
+        "devel": true,
+        "userns": true,
+        "net": true,
+        "tty": true,
+        "multiarch": true,
+        "env": {
+          "GOOGLE_API_KEY": "AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
+          "GOOGLE_DEFAULT_CLIENT_ID": "77185425430.apps.googleusercontent.com",
+          "GOOGLE_DEFAULT_CLIENT_SECRET": "OTJgUOQcT7lO7GsGZq2G4IlT"
+        },
+        "map_real_uid": true,
+        "device": true,
+        "filesystem": [
           {
-            "ensure": true,
+            "src": "/nix/store"
-            "path": "/var/lib/fortify/u0",
-            "x": true
           },
           {
-            "path": "/var/lib/fortify/u0/org.chromium.Chromium",
+            "src": "/run/current-system"
-            "r": true,
+          },
-            "w": true,
+          {
-            "x": true
+            "src": "/run/opengl-driver"
+          },
+          {
+            "src": "/var/db/nix-channels"
+          },
+          {
+            "dst": "/data/data/org.chromium.Chromium",
+            "src": "/var/lib/fortify/u0/org.chromium.Chromium",
+            "write": true,
+            "require": true
+          },
+          {
+            "src": "/dev/dri",
+            "dev": true
           }
         ],
-        "system_bus": {
+        "symlink": [
-          "see": null,
+          [
-          "talk": [
+            "/run/user/65534",
-            "org.bluez",
+            "/run/user/150"
-            "org.freedesktop.Avahi",
+          ]
-            "org.freedesktop.UPower"
+        ],
-          ],
+        "etc": "/etc",
-          "own": null,
+        "auto_etc": true,
-          "call": null,
+        "cover": [
-          "broadcast": null,
+          "/var/run/nscd"
-          "filter": true
+        ]
-        },
-        "session_bus": {
-          "see": null,
-          "talk": [
-            "org.freedesktop.Notifications",
-            "org.freedesktop.FileManager1",
-            "org.freedesktop.ScreenSaver",
-            "org.freedesktop.secrets",
-            "org.kde.kwalletd5",
-            "org.kde.kwalletd6",
-            "org.gnome.SessionManager"
-          ],
-          "own": [
-            "org.chromium.Chromium.*",
-            "org.mpris.MediaPlayer2.org.chromium.Chromium.*",
-            "org.mpris.MediaPlayer2.chromium.*"
-          ],
-          "call": {
-            "org.freedesktop.portal.*": "*"
-          },
-          "broadcast": {
-            "org.freedesktop.portal.*": "@/org/freedesktop/portal/*"
-          },
-          "filter": true
-        },
-        "enablements": 13
       }
     },
     "time": "1970-01-01T00:00:00.000000009Z"

sandbox/container.go

@@ -27,18 +27,18 @@ const (
 	FAllowNet
 )
 
-func (flags HardeningFlags) seccomp(opts seccomp.SyscallOpts) seccomp.SyscallOpts {
+func (flags HardeningFlags) seccomp(opts seccomp.FilterOpts) seccomp.FilterOpts {
 	if flags&FSyscallCompat == 0 {
-		opts |= seccomp.FlagExt
+		opts |= seccomp.FilterExt
 	}
 	if flags&FAllowDevel == 0 {
-		opts |= seccomp.FlagDenyDevel
+		opts |= seccomp.FilterDenyDevel
 	}
 	if flags&FAllowUserns == 0 {
-		opts |= seccomp.FlagDenyNS
+		opts |= seccomp.FilterDenyNS
 	}
 	if flags&FAllowTTY == 0 {
-		opts |= seccomp.FlagDenyTTY
+		opts |= seccomp.FilterDenyTTY
 	}
 	return opts
 }
@@ -95,23 +95,15 @@ type (
 		// Sequential container setup ops.
 		*Ops
 		// Extra seccomp options.
-		Seccomp seccomp.SyscallOpts
+		Seccomp seccomp.FilterOpts
 		// Permission bits of newly created parent directories.
 		// The zero value is interpreted as 0755.
 		ParentPerm os.FileMode
+		// Retain CAP_SYS_ADMIN.
+		Privileged bool
 
 		Flags HardeningFlags
 	}
-
-	Ops []Op
-	Op  interface {
-		early(params *Params) error
-		apply(params *Params) error
-		prefix() string
-
-		Is(op Op) bool
-		fmt.Stringer
-	}
 )
 
 func (p *Container) Start() error {
@@ -165,7 +157,7 @@ func (p *Container) Start() error {
 			syscall.CLONE_NEWNS,
 
 		// remain privileged for setup
-		AmbientCaps: []uintptr{CAP_SYS_ADMIN},
+		AmbientCaps: []uintptr{CAP_SYS_ADMIN, CAP_SETPCAP},
 
 		UseCgroupFD: p.Cgroup != nil,
 	}

sandbox/container_test.go

@@ -164,7 +164,7 @@ func e(root, target, vfsOptstr, fsType, source, fsOptstr string) *vfs.MountInfoE
 func TestContainerString(t *testing.T) {
 	container := sandbox.New(context.TODO(), "ldd", "/usr/bin/env")
 	container.Flags |= sandbox.FAllowDevel
-	container.Seccomp |= seccomp.FlagMultiarch
+	container.Seccomp |= seccomp.FilterMultiarch
 	want := `argv: ["ldd" "/usr/bin/env"], flags: 0x2, seccomp: 0x2e`
 	if got := container.String(); got != want {
 		t.Errorf("String: %s, want %s", got, want)

sandbox/init.go

@@ -45,10 +45,6 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 		log.Fatal("this process must run as pid 1")
 	}
 
-	/*
-		receive setup payload
-	*/
-
 	var (
 		params      initParams
 		closeSetup  func() error
@@ -108,9 +104,8 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 		}
 	}
 
-	/*
+	// cache sysctl before pivot_root
-		set up mount points from intermediate root
+	LastCap()
-	*/
 
 	if err := syscall.Mount("", "/", "",
 		syscall.MS_SILENT|syscall.MS_SLAVE|syscall.MS_REC,
@@ -152,6 +147,7 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 	if err := os.Mkdir(hostDir, 0755); err != nil {
 		log.Fatalf("%v", err)
 	}
+	// pivot_root uncovers basePath in hostDir
 	if err := syscall.PivotRoot(basePath, hostDir); err != nil {
 		log.Fatalf("cannot pivot into intermediate root: %v", err)
 	}
@@ -170,10 +166,7 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 		}
 	}
 
-	/*
+	// setup requiring host root complete at this point
-		pivot to sysroot
-	*/
-
 	if err := syscall.Mount(hostDir, hostDir, "",
 		syscall.MS_SILENT|syscall.MS_REC|syscall.MS_PRIVATE,
 		""); err != nil {
@@ -213,33 +206,48 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 		}
 	}
 
-	/*
+	if _, _, errno := syscall.Syscall(PR_SET_NO_NEW_PRIVS, 1, 0, 0); errno != 0 {
-		load seccomp filter
+		log.Fatalf("prctl(PR_SET_NO_NEW_PRIVS): %v", errno)
-	*/
-
-	if _, _, err := syscall.Syscall(PR_SET_NO_NEW_PRIVS, 1, 0, 0); err != 0 {
-		log.Fatalf("prctl(PR_SET_NO_NEW_PRIVS): %v", err)
 	}
+
+	if _, _, errno := syscall.Syscall(syscall.SYS_PRCTL, PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0); errno != 0 {
+		log.Fatalf("cannot clear the ambient capability set: %v", errno)
+	}
+	for i := uintptr(0); i <= LastCap(); i++ {
+		if params.Privileged && i == CAP_SYS_ADMIN {
+			continue
+		}
+		if _, _, errno := syscall.Syscall(syscall.SYS_PRCTL, syscall.PR_CAPBSET_DROP, i, 0); errno != 0 {
+			log.Fatalf("cannot drop capability from bonding set: %v", errno)
+		}
+	}
+
+	var keep [2]uint32
+	if params.Privileged {
+		keep[capToIndex(CAP_SYS_ADMIN)] |= capToMask(CAP_SYS_ADMIN)
+
+		if _, _, errno := syscall.Syscall(syscall.SYS_PRCTL, PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_SYS_ADMIN); errno != 0 {
+			log.Fatalf("cannot raise CAP_SYS_ADMIN: %v", errno)
+		}
+	}
+	if err := capset(
+		&capHeader{_LINUX_CAPABILITY_VERSION_3, 0},
+		&[2]capData{{0, keep[0], keep[0]}, {0, keep[1], keep[1]}},
+	); err != nil {
+		log.Fatalf("cannot capset: %v", err)
+	}
+
 	if err := seccomp.Load(params.Flags.seccomp(params.Seccomp)); err != nil {
 		log.Fatalf("cannot load syscall filter: %v", err)
 	}
 
-	/* at this point CAP_SYS_ADMIN can be dropped, however it is kept for now as it does not increase attack surface */
-
-	/*
-		pass through extra files
-	*/
-
 	extraFiles := make([]*os.File, params.Count)
 	for i := range extraFiles {
+		// setup fd is placed before all extra files
 		extraFiles[i] = os.NewFile(uintptr(offsetSetup+i), "extra file "+strconv.Itoa(i))
 	}
 	syscall.Umask(oldmask)
 
-	/*
-		prepare initial process
-	*/
-
 	cmd := exec.Command(params.Path)
 	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
 	cmd.Args = params.Args
@@ -252,22 +260,11 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 	}
 	msg.Suspend()
 
-	/*
-		close setup pipe
-	*/
-
 	if err := closeSetup(); err != nil {
 		log.Println("cannot close setup pipe:", err)
 		// not fatal
 	}
 
-	/*
-		perform init duties
-	*/
-
-	sig := make(chan os.Signal, 2)
-	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
-
 	type winfo struct {
 		wpid    int
 		wstatus syscall.WaitStatus
@@ -304,6 +301,10 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 		close(done)
 	}()
 
+	// handle signals to dump withheld messages
+	sig := make(chan os.Signal, 2)
+	signal.Notify(sig, syscall.SIGINT, syscall.SIGTERM)
+
 	// closed after residualProcessTimeout has elapsed after initial process death
 	timeout := make(chan struct{})
 
@@ -316,7 +317,6 @@ func Init(prepare func(prefix string), setVerbose func(verbose bool)) {
 			} else {
 				msg.Verbosef("terminating on %s", s.String())
 			}
-			msg.BeforeExit()
 			os.Exit(0)
 		case w := <-info:
 			if w.wpid == cmd.Process.Pid {

sandbox/ops.go

@@ -13,6 +13,22 @@ import (
 	"unsafe"
 )
 
+type (
+	Ops []Op
+	Op  interface {
+		// early is called in host root.
+		early(params *Params) error
+		// apply is called in intermediate root.
+		apply(params *Params) error
+
+		prefix() string
+		Is(op Op) bool
+		fmt.Stringer
+	}
+)
+
+func (f *Ops) Grow(n int) { *f = slices.Grow(*f, n) }
+
 func init() { gob.Register(new(BindMount)) }
 
 // BindMount bind mounts host path Source on container path Target.
@@ -424,3 +440,60 @@ func (f *Ops) PlaceP(name string, dataP **[]byte) *Ops {
 	*f = append(*f, t)
 	return f
 }
+
+func init() { gob.Register(new(AutoEtc)) }
+
+// AutoEtc expands host /etc into a toplevel symlink mirror with /etc semantics.
+// This is not a generic setup op. It is implemented here to reduce ipc overhead.
+type AutoEtc struct{ Prefix string }
+
+func (e *AutoEtc) early(*Params) error { return nil }
+func (e *AutoEtc) apply(*Params) error {
+	const target = sysrootPath + "/etc/"
+	rel := e.hostRel() + "/"
+
+	if err := os.MkdirAll(target, 0755); err != nil {
+		return wrapErrSelf(err)
+	}
+	if d, err := os.ReadDir(toSysroot(e.hostPath())); err != nil {
+		return wrapErrSelf(err)
+	} else {
+		for _, ent := range d {
+			n := ent.Name()
+			switch n {
+			case ".host":
+
+			case "passwd":
+			case "group":
+
+			case "mtab":
+				if err = os.Symlink("/proc/mounts", target+n); err != nil {
+					return wrapErrSelf(err)
+				}
+
+			default:
+				if err = os.Symlink(rel+n, target+n); err != nil {
+					return wrapErrSelf(err)
+				}
+			}
+		}
+	}
+
+	return nil
+}
+func (e *AutoEtc) hostPath() string { return "/etc/" + e.hostRel() }
+func (e *AutoEtc) hostRel() string  { return ".host/" + e.Prefix }
+
+func (e *AutoEtc) Is(op Op) bool {
+	ve, ok := op.(*AutoEtc)
+	return ok && ((e == nil && ve == nil) || (e != nil && ve != nil && *e == *ve))
+}
+func (*AutoEtc) prefix() string   { return "setting up" }
+func (e *AutoEtc) String() string { return fmt.Sprintf("auto etc %s", e.Prefix) }
+func (f *Ops) Etc(host, prefix string) *Ops {
+	e := &AutoEtc{prefix}
+	f.Mkdir("/etc", 0755)
+	f.Bind(host, e.hostPath(), 0)
+	*f = append(*f, e)
+	return f
+}

sandbox/overflow.go

@@ -1,37 +0,0 @@
-package sandbox
-
-import (
-	"bytes"
-	"log"
-	"os"
-	"strconv"
-	"sync"
-)
-
-var (
-	ofUid  int
-	ofGid  int
-	ofOnce sync.Once
-)
-
-const (
-	ofUidPath = "/proc/sys/kernel/overflowuid"
-	ofGidPath = "/proc/sys/kernel/overflowgid"
-)
-
-func mustReadOverflow() {
-	if v, err := os.ReadFile(ofUidPath); err != nil {
-		log.Fatalf("cannot read %q: %v", ofUidPath, err)
-	} else if ofUid, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
-		log.Fatalf("cannot interpret %q: %v", ofUidPath, err)
-	}
-
-	if v, err := os.ReadFile(ofGidPath); err != nil {
-		log.Fatalf("cannot read %q: %v", ofGidPath, err)
-	} else if ofGid, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
-		log.Fatalf("cannot interpret %q: %v", ofGidPath, err)
-	}
-}
-
-func OverflowUid() int { ofOnce.Do(mustReadOverflow); return ofUid }
-func OverflowGid() int { ofOnce.Do(mustReadOverflow); return ofGid }

sandbox/seccomp/api.go

@@ -8,11 +8,16 @@ import (
 	"git.gensokyo.uk/security/fortify/helper/proc"
 )
 
+const (
+	PresetStrict = FilterExt | FilterDenyNS | FilterDenyTTY | FilterDenyDevel
+	PresetCommon = PresetStrict | FilterMultiarch
+)
+
 // New returns an inactive Encoder instance.
-func New(opts SyscallOpts) *Encoder { return &Encoder{newExporter(opts)} }
+func New(opts FilterOpts) *Encoder { return &Encoder{newExporter(opts)} }
 
 // Load loads a filter into the kernel.
-func Load(opts SyscallOpts) error { return buildFilter(-1, opts) }
+func Load(opts FilterOpts) error { return buildFilter(-1, opts) }
 
 /*
 An Encoder writes a BPF program to an output stream.
@@ -42,11 +47,11 @@ func (e *Encoder) Close() error {
 }
 
 // NewFile returns an instance of exporter implementing [proc.File].
-func NewFile(opts SyscallOpts) proc.File { return &File{opts: opts} }
+func NewFile(opts FilterOpts) proc.File { return &File{opts: opts} }
 
 // File implements [proc.File] and provides access to the read end of exporter pipe.
 type File struct {
-	opts SyscallOpts
+	opts FilterOpts
 	proc.BaseFile
 }
 

sandbox/seccomp/export.go

@@ -7,7 +7,7 @@ import (
 )
 
 type exporter struct {
-	opts SyscallOpts
+	opts FilterOpts
 	r, w *os.File
 
 	prepareOnce sync.Once
@@ -53,6 +53,6 @@ func (e *exporter) closeWrite() error {
 	return e.closeErr
 }
 
-func newExporter(opts SyscallOpts) *exporter {
+func newExporter(opts FilterOpts) *exporter {
 	return &exporter{opts: opts}
 }

sandbox/seccomp/export_test.go

@@ -14,7 +14,7 @@ import (
 func TestExport(t *testing.T) {
 	testCases := []struct {
 		name    string
-		opts    seccomp.SyscallOpts
+		opts    seccomp.FilterOpts
 		want    []byte
 		wantErr bool
 	}{
@@ -28,7 +28,7 @@ func TestExport(t *testing.T) {
 			0xa7, 0x9b, 0x07, 0x0e, 0x04, 0xc0, 0xee, 0x9a,
 			0xcd, 0xf5, 0x8f, 0x55, 0xcf, 0xa8, 0x15, 0xa5,
 		}, false},
-		{"base", seccomp.FlagExt, []byte{
+		{"base", seccomp.FilterExt, []byte{
 			0xdc, 0x7f, 0x2e, 0x1c, 0x5e, 0x82, 0x9b, 0x79,
 			0xeb, 0xb7, 0xef, 0xc7, 0x59, 0x15, 0x0f, 0x54,
 			0xa8, 0x3a, 0x75, 0xc8, 0xdf, 0x6f, 0xee, 0x4d,
@@ -38,10 +38,10 @@ func TestExport(t *testing.T) {
 			0x1d, 0xb0, 0x5d, 0x90, 0x99, 0x7c, 0x86, 0x59,
 			0xb9, 0x58, 0x91, 0x20, 0x6a, 0xc9, 0x95, 0x2d,
 		}, false},
-		{"everything", seccomp.FlagExt |
+		{"everything", seccomp.FilterExt |
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel |
+			seccomp.FilterDenyNS | seccomp.FilterDenyTTY | seccomp.FilterDenyDevel |
-			seccomp.FlagMultiarch | seccomp.FlagLinux32 | seccomp.FlagCan |
+			seccomp.FilterMultiarch | seccomp.FilterLinux32 | seccomp.FilterCan |
-			seccomp.FlagBluetooth, []byte{
+			seccomp.FilterBluetooth, []byte{
 			0xe9, 0x9d, 0xd3, 0x45, 0xe1, 0x95, 0x41, 0x34,
 			0x73, 0xd3, 0xcb, 0xee, 0x07, 0xb4, 0xed, 0x57,
 			0xb9, 0x08, 0xbf, 0xa8, 0x9e, 0xa2, 0x07, 0x2f,
@@ -51,8 +51,7 @@ func TestExport(t *testing.T) {
 			0x4c, 0x02, 0x4e, 0xd4, 0x88, 0x50, 0xbe, 0x69,
 			0xb6, 0x8a, 0x9a, 0x4c, 0x5f, 0x53, 0xa9, 0xdb,
 		}, false},
-		{"strict", seccomp.FlagExt |
+		{"strict", seccomp.PresetStrict, []byte{
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel, []byte{
 			0xe8, 0x80, 0x29, 0x8d, 0xf2, 0xbd, 0x67, 0x51,
 			0xd0, 0x04, 0x0f, 0xc2, 0x1b, 0xc0, 0xed, 0x4c,
 			0x00, 0xf9, 0x5d, 0xc0, 0xd7, 0xba, 0x50, 0x6c,
@@ -63,7 +62,7 @@ func TestExport(t *testing.T) {
 			0x14, 0x89, 0x60, 0xfb, 0xd3, 0x5c, 0xd7, 0x35,
 		}, false},
 		{"strict compat", 0 |
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel, []byte{
+			seccomp.FilterDenyNS | seccomp.FilterDenyTTY | seccomp.FilterDenyDevel, []byte{
 			0x39, 0x87, 0x1b, 0x93, 0xff, 0xaf, 0xc8, 0xb9,
 			0x79, 0xfc, 0xed, 0xc0, 0xb0, 0xc3, 0x7b, 0x9e,
 			0x03, 0x92, 0x2f, 0x5b, 0x02, 0x74, 0x8d, 0xc5,
@@ -73,6 +72,16 @@ func TestExport(t *testing.T) {
 			0x80, 0x8b, 0x1a, 0x6f, 0x84, 0xf3, 0x2b, 0xbd,
 			0xe1, 0xaa, 0x02, 0xae, 0x30, 0xee, 0xdc, 0xfa,
 		}, false},
+		{"fortify default", seccomp.FilterExt | seccomp.FilterDenyDevel, []byte{
+			0xc6, 0x98, 0xb0, 0x81, 0xff, 0x95, 0x7a, 0xfe,
+			0x17, 0xa6, 0xd9, 0x43, 0x74, 0x53, 0x7d, 0x37,
+			0xf2, 0xa6, 0x3f, 0x6f, 0x9d, 0xd7, 0x5d, 0xa7,
+			0x54, 0x65, 0x42, 0x40, 0x7a, 0x9e, 0x32, 0x47,
+			0x6e, 0xbd, 0xa3, 0x31, 0x2b, 0xa7, 0x78, 0x5d,
+			0x7f, 0x61, 0x85, 0x42, 0xbc, 0xfa, 0xf2, 0x7c,
+			0xa2, 0x7d, 0xcc, 0x2d, 0xdd, 0xba, 0x85, 0x20,
+			0x69, 0xd2, 0x8b, 0xcf, 0xe8, 0xca, 0xd3, 0x9a,
+		}, false},
 	}
 
 	buf := make([]byte, 8)
@@ -128,10 +137,10 @@ func TestExport(t *testing.T) {
 func BenchmarkExport(b *testing.B) {
 	buf := make([]byte, 8)
 	for i := 0; i < b.N; i++ {
-		e := seccomp.New(seccomp.FlagExt |
+		e := seccomp.New(seccomp.FilterExt |
-			seccomp.FlagDenyNS | seccomp.FlagDenyTTY | seccomp.FlagDenyDevel |
+			seccomp.FilterDenyNS | seccomp.FilterDenyTTY | seccomp.FilterDenyDevel |
-			seccomp.FlagMultiarch | seccomp.FlagLinux32 | seccomp.FlagCan |
+			seccomp.FilterMultiarch | seccomp.FilterLinux32 | seccomp.FilterCan |
-			seccomp.FlagBluetooth)
+			seccomp.FilterBluetooth)
 		if _, err := io.CopyBuffer(io.Discard, e, buf); err != nil {
 			b.Fatalf("cannot export: %v", err)
 		}

sandbox/seccomp/output.go

@@ -22,8 +22,8 @@ func GetOutput() func(v ...any) {
 	}
 }
 
-//export F_println
+//export f_println
-func F_println(v *C.char) {
+func f_println(v *C.char) {
 	if fp := printlnP.Load(); fp != nil {
 		(*fp)(C.GoString(v))
 	}

sandbox/seccomp/seccomp-build.c

@@ -28,7 +28,7 @@ struct f_syscall_act {
 #define LEN(arr) (sizeof(arr) / sizeof((arr)[0]))
 
 #define SECCOMP_RULESET_ADD(ruleset) do {                                                                         \
-  if (opts & F_VERBOSE) F_println("adding seccomp ruleset \"" #ruleset "\"");                                     \
+  if (opts & F_VERBOSE) f_println("adding seccomp ruleset \"" #ruleset "\"");                                     \
   for (int i = 0; i < LEN(ruleset); i++) {                                                                        \
     assert(ruleset[i].m_errno == EPERM || ruleset[i].m_errno == ENOSYS);                                          \
                                                                                                                   \
@@ -47,7 +47,7 @@ struct f_syscall_act {
   }                                                                                                               \
 } while (0)
 
-int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_syscall_opts opts) {
+int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_filter_opts opts) {
   int32_t res = 0; // refer to resErr for meaning
   int allow_multiarch = opts & F_MULTIARCH;
   int allowed_personality = PER_LINUX;
@@ -209,7 +209,7 @@ int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_
   struct
   {
     int            family;
-    f_syscall_opts flags_mask;
+    f_filter_opts flags_mask;
   } socket_family_allowlist[] = {
     // NOTE: Keep in numerical order
     { AF_UNSPEC, 0 },

sandbox/seccomp/seccomp-build.h

@@ -17,7 +17,7 @@ typedef enum {
   F_LINUX32    = 1 << 6,
   F_CAN        = 1 << 7,
   F_BLUETOOTH  = 1 << 8,
-} f_syscall_opts;
+} f_filter_opts;
 
-extern void F_println(char *v);
+extern void f_println(char *v);
-int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_syscall_opts opts);
+int32_t f_build_filter(int *ret_p, int fd, uint32_t arch, uint32_t multiarch, f_filter_opts opts);

sandbox/seccomp/seccomp.go

@@ -1,3 +1,4 @@
+// Package seccomp provides filter presets and high level wrappers around libseccomp.
 package seccomp
 
 /*
@@ -6,6 +7,7 @@ package seccomp
 #include "seccomp-build.h"
 */
 import "C"
+
 import (
 	"errors"
 	"fmt"
@@ -55,29 +57,29 @@ var resPrefix = [...]string{
 	7: "seccomp_load failed",
 }
 
-type SyscallOpts = C.f_syscall_opts
+type FilterOpts = C.f_filter_opts
 
 const (
-	flagVerbose SyscallOpts = C.F_VERBOSE
+	filterVerbose FilterOpts = C.F_VERBOSE
-	// FlagExt are project-specific extensions.
+	// FilterExt are project-specific extensions.
-	FlagExt SyscallOpts = C.F_EXT
+	FilterExt FilterOpts = C.F_EXT
-	// FlagDenyNS denies namespace setup syscalls.
+	// FilterDenyNS denies namespace setup syscalls.
-	FlagDenyNS SyscallOpts = C.F_DENY_NS
+	FilterDenyNS FilterOpts = C.F_DENY_NS
-	// FlagDenyTTY denies faking input.
+	// FilterDenyTTY denies faking input.
-	FlagDenyTTY SyscallOpts = C.F_DENY_TTY
+	FilterDenyTTY FilterOpts = C.F_DENY_TTY
-	// FlagDenyDevel denies development-related syscalls.
+	// FilterDenyDevel denies development-related syscalls.
-	FlagDenyDevel SyscallOpts = C.F_DENY_DEVEL
+	FilterDenyDevel FilterOpts = C.F_DENY_DEVEL
-	// FlagMultiarch allows multiarch/emulation.
+	// FilterMultiarch allows multiarch/emulation.
-	FlagMultiarch SyscallOpts = C.F_MULTIARCH
+	FilterMultiarch FilterOpts = C.F_MULTIARCH
-	// FlagLinux32 sets PER_LINUX32.
+	// FilterLinux32 sets PER_LINUX32.
-	FlagLinux32 SyscallOpts = C.F_LINUX32
+	FilterLinux32 FilterOpts = C.F_LINUX32
-	// FlagCan allows AF_CAN.
+	// FilterCan allows AF_CAN.
-	FlagCan SyscallOpts = C.F_CAN
+	FilterCan FilterOpts = C.F_CAN
-	// FlagBluetooth allows AF_BLUETOOTH.
+	// FilterBluetooth allows AF_BLUETOOTH.
-	FlagBluetooth SyscallOpts = C.F_BLUETOOTH
+	FilterBluetooth FilterOpts = C.F_BLUETOOTH
 )
 
-func buildFilter(fd int, opts SyscallOpts) error {
+func buildFilter(fd int, opts FilterOpts) error {
 	var (
 		arch      C.uint32_t = 0
 		multiarch C.uint32_t = 0
@@ -98,7 +100,7 @@ func buildFilter(fd int, opts SyscallOpts) error {
 	// this removes repeated transitions between C and Go execution
 	// when producing log output via F_println and CPrintln is nil
 	if fp := printlnP.Load(); fp != nil {
-		opts |= flagVerbose
+		opts |= filterVerbose
 	}
 
 	var ret C.int

sandbox/syscall.go

@@ -1,11 +1,17 @@
 package sandbox
 
-import "syscall"
+import (
+	"syscall"
+	"unsafe"
+)
 
 const (
-	O_PATH              = 0x200000
+	O_PATH = 0x200000
+
 	PR_SET_NO_NEW_PRIVS = 0x26
-	CAP_SYS_ADMIN       = 0x15
+
+	CAP_SYS_ADMIN = 0x15
+	CAP_SETPCAP   = 0x8
 )
 
 const (
@@ -15,13 +21,49 @@ const (
 
 func SetDumpable(dumpable uintptr) error {
 	// linux/sched/coredump.h
-	if _, _, errno := syscall.RawSyscall(syscall.SYS_PRCTL, syscall.PR_SET_DUMPABLE, dumpable, 0); errno != 0 {
+	if _, _, errno := syscall.Syscall(syscall.SYS_PRCTL, syscall.PR_SET_DUMPABLE, dumpable, 0); errno != 0 {
 		return errno
 	}
 
 	return nil
 }
 
+const (
+	_LINUX_CAPABILITY_VERSION_3 = 0x20080522
+
+	PR_CAP_AMBIENT           = 0x2f
+	PR_CAP_AMBIENT_RAISE     = 0x2
+	PR_CAP_AMBIENT_CLEAR_ALL = 0x4
+)
+
+type (
+	capHeader struct {
+		version uint32
+		pid     int32
+	}
+
+	capData struct {
+		effective   uint32
+		permitted   uint32
+		inheritable uint32
+	}
+)
+
+// See CAP_TO_INDEX in linux/capability.h:
+func capToIndex(cap uintptr) uintptr { return cap >> 5 }
+
+// See CAP_TO_MASK in linux/capability.h:
+func capToMask(cap uintptr) uint32 { return 1 << uint(cap&31) }
+
+func capset(hdrp *capHeader, datap *[2]capData) error {
+	if _, _, errno := syscall.Syscall(syscall.SYS_CAPSET,
+		uintptr(unsafe.Pointer(hdrp)),
+		uintptr(unsafe.Pointer(&datap[0])), 0); errno != 0 {
+		return errno
+	}
+	return nil
+}
+
 // IgnoringEINTR makes a function call and repeats it if it returns an
 // EINTR error. This appears to be required even though we install all
 // signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.

sandbox/sysctl.go

@@ -0,0 +1,47 @@
+package sandbox
+
+import (
+	"bytes"
+	"log"
+	"os"
+	"strconv"
+	"sync"
+)
+
+var (
+	kernelOverflowuid int
+	kernelOverflowgid int
+	kernelCapLastCap  int
+
+	sysctlOnce sync.Once
+)
+
+const (
+	kernelOverflowuidPath = "/proc/sys/kernel/overflowuid"
+	kernelOverflowgidPath = "/proc/sys/kernel/overflowgid"
+	kernelCapLastCapPath  = "/proc/sys/kernel/cap_last_cap"
+)
+
+func mustReadSysctl() {
+	if v, err := os.ReadFile(kernelOverflowuidPath); err != nil {
+		log.Fatalf("cannot read %q: %v", kernelOverflowuidPath, err)
+	} else if kernelOverflowuid, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
+		log.Fatalf("cannot interpret %q: %v", kernelOverflowuidPath, err)
+	}
+
+	if v, err := os.ReadFile(kernelOverflowgidPath); err != nil {
+		log.Fatalf("cannot read %q: %v", kernelOverflowgidPath, err)
+	} else if kernelOverflowgid, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
+		log.Fatalf("cannot interpret %q: %v", kernelOverflowgidPath, err)
+	}
+
+	if v, err := os.ReadFile(kernelCapLastCapPath); err != nil {
+		log.Fatalf("cannot read %q: %v", kernelCapLastCapPath, err)
+	} else if kernelCapLastCap, err = strconv.Atoi(string(bytes.TrimSpace(v))); err != nil {
+		log.Fatalf("cannot interpret %q: %v", kernelCapLastCapPath, err)
+	}
+}
+
+func OverflowUid() int { sysctlOnce.Do(mustReadSysctl); return kernelOverflowuid }
+func OverflowGid() int { sysctlOnce.Do(mustReadSysctl); return kernelOverflowgid }
+func LastCap() uintptr { sysctlOnce.Do(mustReadSysctl); return uintptr(kernelCapLastCap) }

test/configuration.nix

@@ -4,12 +4,6 @@
   config,
   ...
 }:
-let
-  testCases = import ./sandbox/case {
-    inherit (pkgs) lib callPackage foot;
-    inherit (config.environment.fortify.package) version;
-  };
-in
 {
   users.users = {
     alice = {
@@ -108,10 +102,6 @@ in
     home-manager = _: _: { home.stateVersion = "23.05"; };
 
     apps = [
-      testCases.preset
-      testCases.tty
-      testCases.mapuid
-
       {
         name = "ne-foot";
         verbose = true;

test/sandbox/assert.go

@@ -7,10 +7,15 @@ in the public sandbox/vfs package. Files in this package are excluded by the bui
 package sandbox
 
 import (
+	"crypto/sha512"
+	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"io/fs"
 	"log"
 	"os"
+	"syscall"
+	"time"
 )
 
 var (
@@ -23,6 +28,7 @@ func printf(format string, v ...any) { printfFunc(format, v...) }
 func fatalf(format string, v ...any) { fatalfFunc(format, v...) }
 
 type TestCase struct {
+	Env     []string          `json:"env"`
 	FS      *FS               `json:"fs"`
 	Mount   []*MountinfoEntry `json:"mount"`
 	Seccomp bool              `json:"seccomp"`
@@ -34,13 +40,46 @@ type T struct {
 	MountsPath string
 }
 
-func (t *T) MustCheckFile(wantFilePath string) {
+func (t *T) MustCheckFile(wantFilePath, markerPath string) {
 	var want *TestCase
 	mustDecode(wantFilePath, &want)
 	t.MustCheck(want)
+	if _, err := os.Create(markerPath); err != nil {
+		fatalf("cannot create success marker: %v", err)
+	}
 }
 
 func (t *T) MustCheck(want *TestCase) {
+	if want.Env != nil {
+		var (
+			fail bool
+			i    int
+			got  string
+		)
+		for i, got = range os.Environ() {
+			if i == len(want.Env) {
+				fatalf("got more than %d environment variables", len(want.Env))
+			}
+			if got != want.Env[i] {
+				fail = true
+				printf("[FAIL] %s", got)
+			} else {
+				printf("[ OK ] %s", got)
+			}
+		}
+
+		i++
+		if i != len(want.Env) {
+			fatalf("got %d environment variables, want %d", i, len(want.Env))
+		}
+
+		if fail {
+			fatalf("[FAIL] some environment variables did not match")
+		}
+	} else {
+		printf("[SKIP] skipping environ check")
+	}
+
 	if want.FS != nil && t.FS != nil {
 		if err := want.FS.Compare(".", t.FS); err != nil {
 			fatalf("%v", err)
@@ -82,7 +121,7 @@ func (t *T) MustCheck(want *TestCase) {
 	}
 
 	if want.Seccomp {
-		if TrySyscalls() != nil {
+		if trySyscalls() != nil {
 			os.Exit(1)
 		}
 	} else {
@@ -90,6 +129,81 @@ func (t *T) MustCheck(want *TestCase) {
 	}
 }
 
+func MustCheckFilter(pid int, want string) {
+	err := CheckFilter(pid, want)
+	if err == nil {
+		return
+	}
+
+	var perr *ptraceError
+	if !errors.As(err, &perr) {
+		fatalf("%s", err)
+	}
+	switch perr.op {
+	case "PTRACE_ATTACH":
+		fatalf("cannot attach to process %d: %v", pid, err)
+	case "PTRACE_SECCOMP_GET_FILTER":
+		if perr.errno == syscall.ENOENT {
+			fatalf("seccomp filter not installed for process %d", pid)
+		}
+		fatalf("cannot get filter: %v", err)
+	default:
+		fatalf("cannot check filter: %v", err)
+	}
+
+	*(*int)(nil) = 0 // not reached
+}
+
+func CheckFilter(pid int, want string) error {
+	if err := ptraceAttach(pid); err != nil {
+		return err
+	}
+	defer func() {
+		if err := ptraceDetach(pid); err != nil {
+			printf("cannot detach from process %d: %v", pid, err)
+		}
+	}()
+
+	h := sha512.New()
+	{
+	getFilter:
+		buf, err := getFilter[[8]byte](pid, 0)
+		/* this is not how ESRCH should be handled: the manpage advises the
+		use of waitpid, however that is not applicable for attaching to an
+		arbitrary process, and spawning target process here is not easily
+		possible under the current testing framework;
+
+		despite checking for /proc/pid/status indicating state t (tracing stop),
+		it does not appear to be directly related to the internal state used to
+		determine whether a process is ready to accept ptrace operations, it also
+		introduces a TOCTOU that is irrelevant in the testing vm; this behaviour
+		is kept anyway as it reduces the average iterations required here;
+
+		since this code is only ever compiled into the test program, whatever
+		implications this ugliness might have should not hurt anyone */
+		if errors.Is(err, syscall.ESRCH) {
+			time.Sleep(100 * time.Millisecond)
+			goto getFilter
+		}
+
+		if err != nil {
+			return err
+		}
+
+		for _, b := range buf {
+			h.Write(b[:])
+		}
+	}
+
+	if got := hex.EncodeToString(h.Sum(nil)); got != want {
+		printf("[FAIL] %s", got)
+		return syscall.ENOTRECOVERABLE
+	} else {
+		printf("[ OK ] %s", got)
+		return nil
+	}
+}
+
 func mustDecode(wantFilePath string, v any) {
 	if f, err := os.Open(wantFilePath); err != nil {
 		fatalf("cannot open %q: %v", wantFilePath, err)

test/sandbox/assert.nix

@@ -1,30 +0,0 @@
-{
-  writeText,
-  buildGoModule,
-  pkg-config,
-  util-linux,
-
-  version,
-}:
-buildGoModule {
-  pname = "check-sandbox";
-  inherit version;
-
-  src = ../.;
-  vendorHash = null;
-
-  buildInputs = [ util-linux ];
-  nativeBuildInputs = [ pkg-config ];
-
-  preBuild = ''
-    go mod init git.gensokyo.uk/security/fortify/test >& /dev/null
-    cp ${writeText "main.go" ''
-      package main
-
-      import "os"
-      import "git.gensokyo.uk/security/fortify/test/sandbox"
-
-      func main() { (&sandbox.T{FS: os.DirFS("/")}).MustCheckFile(os.Args[1]) }
-    ''} main.go
-  '';
-}

test/sandbox/case/default.nix

@@ -1,10 +1,4 @@
-{
+lib: testProgram:
-  lib,
-  callPackage,
-  foot,
-
-  version,
-}:
 let
   fs = mode: dir: data: {
     mode = lib.fromHexString mode;
@@ -29,8 +23,6 @@ let
       ;
   };
 
-  checkSandbox = callPackage ../. { inherit version; };
-
   callTestCase =
     path:
     let
@@ -45,14 +37,19 @@ let
     {
       name = "check-sandbox-${tc.name}";
       verbose = true;
-      inherit (tc) tty mapRealUid;
+      inherit (tc) tty device mapRealUid;
-      share = foot;
+      share = testProgram;
       packages = [ ];
-      command = builtins.toString (checkSandbox tc.name tc.want);
+      path = "${testProgram}/bin/fortify-test";
+      args = [
+        "test"
+        (toString (builtins.toFile "fortify-${tc.name}-want.json" (builtins.toJSON tc.want)))
+      ];
     };
 in
 {
   preset = callTestCase ./preset.nix;
   tty = callTestCase ./tty.nix;
   mapuid = callTestCase ./mapuid.nix;
+  device = callTestCase ./device.nix;
 }

test/sandbox/case/device.nix

@@ -0,0 +1,203 @@
+{
+  fs,
+  ent,
+  ignore,
+}:
+{
+  name = "device";
+  tty = false;
+  device = true;
+  mapRealUid = false;
+
+  want = {
+    env = [
+      "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/65534/bus"
+      "HOME=/var/lib/fortify/u0/a4"
+      "PULSE_SERVER=unix:/run/user/65534/pulse/native"
+      "SHELL=/run/current-system/sw/bin/bash"
+      "TERM=linux"
+      "USER=u0_a4"
+      "WAYLAND_DISPLAY=wayland-0"
+      "XDG_RUNTIME_DIR=/run/user/65534"
+      "XDG_SESSION_CLASS=user"
+      "XDG_SESSION_TYPE=tty"
+    ];
+
+    fs = fs "dead" {
+      ".fortify" = fs "800001ed" { } null;
+      bin = fs "800001ed" { sh = fs "80001ff" null null; } null;
+      dev = fs "800001ed" null null;
+      etc = fs "800001ed" {
+        ".clean" = fs "80001ff" null null;
+        ".host" = fs "800001c0" null null;
+        ".updated" = fs "80001ff" null null;
+        "NIXOS" = fs "80001ff" null null;
+        "X11" = fs "80001ff" null null;
+        "alsa" = fs "80001ff" null null;
+        "bashrc" = fs "80001ff" null null;
+        "binfmt.d" = fs "80001ff" null null;
+        "dbus-1" = fs "80001ff" null null;
+        "default" = fs "80001ff" null null;
+        "dhcpcd.exit-hook" = fs "80001ff" null null;
+        "fonts" = fs "80001ff" null null;
+        "fstab" = fs "80001ff" null null;
+        "fsurc" = fs "80001ff" null null;
+        "fuse.conf" = fs "80001ff" null null;
+        "group" = fs "180" null "fortify:x:65534:\n";
+        "host.conf" = fs "80001ff" null null;
+        "hostname" = fs "80001ff" null null;
+        "hosts" = fs "80001ff" null null;
+        "inputrc" = fs "80001ff" null null;
+        "issue" = fs "80001ff" null null;
+        "kbd" = fs "80001ff" null null;
+        "locale.conf" = fs "80001ff" null null;
+        "login.defs" = fs "80001ff" null null;
+        "lsb-release" = fs "80001ff" null null;
+        "lvm" = fs "80001ff" null null;
+        "machine-id" = fs "80001ff" null null;
+        "man_db.conf" = fs "80001ff" null null;
+        "modprobe.d" = fs "80001ff" null null;
+        "modules-load.d" = fs "80001ff" null null;
+        "mtab" = fs "80001ff" null null;
+        "nanorc" = fs "80001ff" null null;
+        "netgroup" = fs "80001ff" null null;
+        "nix" = fs "80001ff" null null;
+        "nixos" = fs "80001ff" null null;
+        "nscd.conf" = fs "80001ff" null null;
+        "nsswitch.conf" = fs "80001ff" null null;
+        "os-release" = fs "80001ff" null null;
+        "pam" = fs "80001ff" null null;
+        "pam.d" = fs "80001ff" null null;
+        "passwd" = fs "180" null "u0_a4:x:65534:65534:Fortify:/var/lib/fortify/u0/a4:/run/current-system/sw/bin/bash\n";
+        "pipewire" = fs "80001ff" null null;
+        "pki" = fs "80001ff" null null;
+        "polkit-1" = fs "80001ff" null null;
+        "profile" = fs "80001ff" null null;
+        "protocols" = fs "80001ff" null null;
+        "resolv.conf" = fs "80001ff" null null;
+        "resolvconf.conf" = fs "80001ff" null null;
+        "rpc" = fs "80001ff" null null;
+        "services" = fs "80001ff" null null;
+        "set-environment" = fs "80001ff" null null;
+        "shadow" = fs "80001ff" null null;
+        "shells" = fs "80001ff" null null;
+        "ssh" = fs "80001ff" null null;
+        "ssl" = fs "80001ff" null null;
+        "static" = fs "80001ff" null null;
+        "subgid" = fs "80001ff" null null;
+        "subuid" = fs "80001ff" null null;
+        "sudoers" = fs "80001ff" null null;
+        "sway" = fs "80001ff" null null;
+        "sysctl.d" = fs "80001ff" null null;
+        "systemd" = fs "80001ff" null null;
+        "terminfo" = fs "80001ff" null null;
+        "tmpfiles.d" = fs "80001ff" null null;
+        "udev" = fs "80001ff" null null;
+        "vconsole.conf" = fs "80001ff" null null;
+        "xdg" = fs "80001ff" null null;
+        "zoneinfo" = fs "80001ff" null null;
+      } null;
+      nix = fs "800001c0" { store = fs "801001fd" null null; } null;
+      proc = fs "8000016d" null null;
+      run = fs "800001ed" {
+        current-system = fs "80001ff" null null;
+        opengl-driver = fs "80001ff" null null;
+        user = fs "800001ed" {
+          "65534" = fs "800001c0" {
+            bus = fs "10001fd" null null;
+            pulse = fs "800001c0" { native = fs "10001b6" null null; } null;
+            wayland-0 = fs "1000038" null null;
+          } null;
+        } null;
+      } null;
+      sys = fs "800001c0" {
+        block = fs "800001ed" {
+          fd0 = fs "80001ff" null null;
+          loop0 = fs "80001ff" null null;
+          loop1 = fs "80001ff" null null;
+          loop2 = fs "80001ff" null null;
+          loop3 = fs "80001ff" null null;
+          loop4 = fs "80001ff" null null;
+          loop5 = fs "80001ff" null null;
+          loop6 = fs "80001ff" null null;
+          loop7 = fs "80001ff" null null;
+          sr0 = fs "80001ff" null null;
+          vda = fs "80001ff" null null;
+        } null;
+        bus = fs "800001ed" null null;
+        class = fs "800001ed" null null;
+        dev = fs "800001ed" {
+          block = fs "800001ed" null null;
+          char = fs "800001ed" null null;
+        } null;
+        devices = fs "800001ed" null null;
+      } null;
+      tmp = fs "800001f8" { } null;
+      usr = fs "800001c0" { bin = fs "800001ed" { env = fs "80001ff" null null; } null; } null;
+      var = fs "800001c0" {
+        lib = fs "800001c0" {
+          fortify = fs "800001c0" {
+            u0 = fs "800001c0" {
+              a4 = fs "800001c0" {
+                ".cache" = fs "800001ed" { ".keep" = fs "80001ff" null ""; } null;
+                ".config" = fs "800001ed" { "environment.d" = fs "800001ed" { "10-home-manager.conf" = fs "80001ff" null null; } null; } null;
+                ".local" = fs "800001ed" {
+                  state = fs "800001ed" {
+                    home-manager = fs "800001ed" { gcroots = fs "800001ed" { current-home = fs "80001ff" null null; } null; } null;
+                    nix = fs "800001ed" {
+                      profiles = fs "800001ed" {
+                        home-manager = fs "80001ff" null null;
+                        home-manager-1-link = fs "80001ff" null null;
+                        profile = fs "80001ff" null null;
+                        profile-1-link = fs "80001ff" null null;
+                      } null;
+                    } null;
+                  } null;
+                } null;
+                ".nix-defexpr" = fs "800001ed" {
+                  channels = fs "80001ff" null null;
+                  channels_root = fs "80001ff" null null;
+                } null;
+                ".nix-profile" = fs "80001ff" null null;
+              } null;
+            } null;
+          } null;
+        } null;
+        run = fs "800001ed" { nscd = fs "800001ed" { } null; } null;
+      } null;
+    } null;
+
+    mount = [
+      (ent "/sysroot" "/" "rw,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000004,gid=1000004")
+      (ent "/" "/proc" "rw,nosuid,nodev,noexec,relatime" "proc" "proc" "rw")
+      (ent "/" "/.fortify" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=4k,mode=755,uid=1000004,gid=1000004")
+      (ent "/" "/dev" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
+      (ent "/" "/dev/pts" "rw,nosuid,noexec,relatime" "devpts" "devpts" "rw,gid=3,mode=620,ptmxmode=666")
+      (ent "/" "/dev/shm" "rw,nosuid,nodev" "tmpfs" "tmpfs" ignore)
+      (ent "/" ignore ignore ignore ignore ignore) # order not deterministic
+      (ent "/" ignore ignore ignore ignore ignore)
+      (ent "/bin" "/bin" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/usr/bin" "/usr/bin" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/" "/nix/store" "ro,nosuid,nodev,relatime" "overlay" "overlay" "rw,lowerdir=/mnt-root/nix/.ro-store,upperdir=/mnt-root/nix/.rw-store/upper,workdir=/mnt-root/nix/.rw-store/work,uuid=on")
+      (ent "/block" "/sys/block" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
+      (ent "/bus" "/sys/bus" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
+      (ent "/class" "/sys/class" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
+      (ent "/dev" "/sys/dev" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
+      (ent "/devices" "/sys/devices" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
+      (ent "/dri" "/dev/dri" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
+      (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=4k,mode=755,uid=1000004,gid=1000004")
+      (ent "/" "/run/user/65534" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=700,uid=1000004,gid=1000004")
+      (ent "/tmp/fortify.1000/tmpdir/4" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/var/lib/fortify/u0/a4" "/var/lib/fortify/u0/a4" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000004,gid=1000004")
+      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000004,gid=1000004")
+      (ent ignore "/run/user/65534/wayland-0" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent ignore "/run/user/65534/pulse/native" "ro,nosuid,nodev,relatime" "tmpfs" "tmpfs" ignore)
+      (ent ignore "/run/user/65534/bus" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/" "/var/run/nscd" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8k,mode=755,uid=1000004,gid=1000004")
+    ];
+
+    seccomp = true;
+  };
+}

test/sandbox/case/mapuid.nix

@@ -6,13 +6,25 @@
 {
   name = "mapuid";
   tty = false;
+  device = false;
   mapRealUid = true;
 
   want = {
+    env = [
+      "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus"
+      "HOME=/var/lib/fortify/u0/a3"
+      "PULSE_SERVER=unix:/run/user/1000/pulse/native"
+      "SHELL=/run/current-system/sw/bin/bash"
+      "TERM=linux"
+      "USER=u0_a3"
+      "WAYLAND_DISPLAY=wayland-0"
+      "XDG_RUNTIME_DIR=/run/user/1000"
+      "XDG_SESSION_CLASS=user"
+      "XDG_SESSION_TYPE=tty"
+    ];
+
     fs = fs "dead" {
-      ".fortify" = fs "800001ed" {
+      ".fortify" = fs "800001ed" { } null;
-        etc = fs "800001ed" null null;
-      } null;
       bin = fs "800001ed" { sh = fs "80001ff" null null; } null;
       dev = fs "800001ed" {
         core = fs "80001ff" null null;
@@ -41,6 +53,7 @@
       } null;
       etc = fs "800001ed" {
         ".clean" = fs "80001ff" null null;
+        ".host" = fs "800001c0" null null;
         ".updated" = fs "80001ff" null null;
         "NIXOS" = fs "80001ff" null null;
         "X11" = fs "80001ff" null null;
@@ -84,7 +97,6 @@
         "pki" = fs "80001ff" null null;
         "polkit-1" = fs "80001ff" null null;
         "profile" = fs "80001ff" null null;
-        "profiles" = fs "80001ff" null null;
         "protocols" = fs "80001ff" null null;
         "resolv.conf" = fs "80001ff" null null;
         "resolvconf.conf" = fs "80001ff" null null;
@@ -115,7 +127,7 @@
         current-system = fs "80001ff" null null;
         opengl-driver = fs "80001ff" null null;
         user = fs "800001ed" {
-          "1000" = fs "800001ed" {
+          "1000" = fs "800001c0" {
             bus = fs "10001fd" null null;
             pulse = fs "800001c0" { native = fs "10001b6" null null; } null;
             wayland-0 = fs "1000038" null null;
@@ -201,9 +213,9 @@
       (ent "/dev" "/sys/dev" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
       (ent "/devices" "/sys/devices" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
       (ent "/dri" "/dev/dri" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
-      (ent "/etc" "/.fortify/etc" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=4k,mode=755,uid=1000003,gid=1000003")
-      (ent "/" "/run/user/1000" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=755,uid=1000003,gid=1000003")
+      (ent "/" "/run/user/1000" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=700,uid=1000003,gid=1000003")
       (ent "/tmp/fortify.1000/tmpdir/3" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/var/lib/fortify/u0/a3" "/var/lib/fortify/u0/a3" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000003,gid=1000003")

test/sandbox/case/preset.nix

@@ -6,13 +6,25 @@
 {
   name = "preset";
   tty = false;
+  device = false;
   mapRealUid = false;
 
   want = {
+    env = [
+      "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/65534/bus"
+      "HOME=/var/lib/fortify/u0/a1"
+      "PULSE_SERVER=unix:/run/user/65534/pulse/native"
+      "SHELL=/run/current-system/sw/bin/bash"
+      "TERM=linux"
+      "USER=u0_a1"
+      "WAYLAND_DISPLAY=wayland-0"
+      "XDG_RUNTIME_DIR=/run/user/65534"
+      "XDG_SESSION_CLASS=user"
+      "XDG_SESSION_TYPE=tty"
+    ];
+
     fs = fs "dead" {
-      ".fortify" = fs "800001ed" {
+      ".fortify" = fs "800001ed" { } null;
-        etc = fs "800001ed" null null;
-      } null;
       bin = fs "800001ed" { sh = fs "80001ff" null null; } null;
       dev = fs "800001ed" {
         core = fs "80001ff" null null;
@@ -41,6 +53,7 @@
       } null;
       etc = fs "800001ed" {
         ".clean" = fs "80001ff" null null;
+        ".host" = fs "800001c0" null null;
         ".updated" = fs "80001ff" null null;
         "NIXOS" = fs "80001ff" null null;
         "X11" = fs "80001ff" null null;
@@ -84,7 +97,6 @@
         "pki" = fs "80001ff" null null;
         "polkit-1" = fs "80001ff" null null;
         "profile" = fs "80001ff" null null;
-        "profiles" = fs "80001ff" null null;
         "protocols" = fs "80001ff" null null;
         "resolv.conf" = fs "80001ff" null null;
         "resolvconf.conf" = fs "80001ff" null null;
@@ -115,7 +127,7 @@
         current-system = fs "80001ff" null null;
         opengl-driver = fs "80001ff" null null;
         user = fs "800001ed" {
-          "65534" = fs "800001ed" {
+          "65534" = fs "800001c0" {
             bus = fs "10001fd" null null;
             pulse = fs "800001c0" { native = fs "10001b6" null null; } null;
             wayland-0 = fs "1000038" null null;
@@ -201,9 +213,9 @@
       (ent "/dev" "/sys/dev" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
       (ent "/devices" "/sys/devices" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
       (ent "/dri" "/dev/dri" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
-      (ent "/etc" "/.fortify/etc" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=4k,mode=755,uid=1000001,gid=1000001")
-      (ent "/" "/run/user/65534" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=755,uid=1000001,gid=1000001")
+      (ent "/" "/run/user/65534" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=700,uid=1000001,gid=1000001")
       (ent "/tmp/fortify.1000/tmpdir/1" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/var/lib/fortify/u0/a1" "/var/lib/fortify/u0/a1" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000001,gid=1000001")

test/sandbox/case/tty.nix

@@ -6,13 +6,25 @@
 {
   name = "tty";
   tty = true;
+  device = false;
   mapRealUid = false;
 
   want = {
+    env = [
+      "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/65534/bus"
+      "HOME=/var/lib/fortify/u0/a2"
+      "PULSE_SERVER=unix:/run/user/65534/pulse/native"
+      "SHELL=/run/current-system/sw/bin/bash"
+      "TERM=linux"
+      "USER=u0_a2"
+      "WAYLAND_DISPLAY=wayland-0"
+      "XDG_RUNTIME_DIR=/run/user/65534"
+      "XDG_SESSION_CLASS=user"
+      "XDG_SESSION_TYPE=tty"
+    ];
+
     fs = fs "dead" {
-      ".fortify" = fs "800001ed" {
+      ".fortify" = fs "800001ed" { } null;
-        etc = fs "800001ed" null null;
-      } null;
       bin = fs "800001ed" { sh = fs "80001ff" null null; } null;
       dev = fs "800001ed" {
         console = fs "4200190" null null;
@@ -42,6 +54,7 @@
       } null;
       etc = fs "800001ed" {
         ".clean" = fs "80001ff" null null;
+        ".host" = fs "800001c0" null null;
         ".updated" = fs "80001ff" null null;
         "NIXOS" = fs "80001ff" null null;
         "X11" = fs "80001ff" null null;
@@ -85,7 +98,6 @@
         "pki" = fs "80001ff" null null;
         "polkit-1" = fs "80001ff" null null;
         "profile" = fs "80001ff" null null;
-        "profiles" = fs "80001ff" null null;
         "protocols" = fs "80001ff" null null;
         "resolv.conf" = fs "80001ff" null null;
         "resolvconf.conf" = fs "80001ff" null null;
@@ -116,7 +128,7 @@
         current-system = fs "80001ff" null null;
         opengl-driver = fs "80001ff" null null;
         user = fs "800001ed" {
-          "65534" = fs "800001ed" {
+          "65534" = fs "800001c0" {
             bus = fs "10001fd" null null;
             pulse = fs "800001c0" { native = fs "10001b6" null null; } null;
             wayland-0 = fs "1000038" null null;
@@ -203,9 +215,9 @@
       (ent "/dev" "/sys/dev" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
       (ent "/devices" "/sys/devices" "ro,nosuid,nodev,noexec,relatime" "sysfs" "sysfs" "rw")
       (ent "/dri" "/dev/dri" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
-      (ent "/etc" "/.fortify/etc" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=4k,mode=755,uid=1000002,gid=1000002")
-      (ent "/" "/run/user/65534" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=755,uid=1000002,gid=1000002")
+      (ent "/" "/run/user/65534" "rw,nosuid,nodev,relatime" "tmpfs" "tmpfs" "rw,size=8192k,mode=700,uid=1000002,gid=1000002")
       (ent "/tmp/fortify.1000/tmpdir/2" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/var/lib/fortify/u0/a2" "/var/lib/fortify/u0/a2" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000002,gid=1000002")

test/sandbox/configuration.nix

@@ -0,0 +1,77 @@
+{
+  lib,
+  pkgs,
+  config,
+  ...
+}:
+let
+  testProgram = pkgs.callPackage ./tool/package.nix { inherit (config.environment.fortify.package) version; };
+  testCases = import ./case lib testProgram;
+in
+{
+  users.users = {
+    alice = {
+      isNormalUser = true;
+      description = "Alice Foobar";
+      password = "foobar";
+      uid = 1000;
+    };
+  };
+
+  home-manager.users.alice.home.stateVersion = "24.11";
+
+  # Automatically login on tty1 as a normal user:
+  services.getty.autologinUser = "alice";
+
+  environment = {
+    systemPackages = with pkgs; [
+      # For checking seccomp outcome:
+      testProgram
+    ];
+
+    variables = {
+      SWAYSOCK = "/tmp/sway-ipc.sock";
+      WLR_RENDERER = "pixman";
+    };
+  };
+
+  # Automatically configure and start Sway when logging in on tty1:
+  programs.bash.loginShellInit = ''
+    if [ "$(tty)" = "/dev/tty1" ]; then
+      set -e
+
+      mkdir -p ~/.config/sway
+      (sed s/Mod4/Mod1/ /etc/sway/config &&
+      echo 'output * bg ${pkgs.nixos-artwork.wallpapers.simple-light-gray.gnomeFilePath} fill' &&
+      echo 'output Virtual-1 res 1680x1050') > ~/.config/sway/config
+
+      sway --validate
+      systemd-cat --identifier=session sway && touch /tmp/sway-exit-ok
+    fi
+  '';
+
+  programs.sway.enable = true;
+
+  virtualisation.qemu.options = [
+    # Need to switch to a different GPU driver than the default one (-vga std) so that Sway can launch:
+    "-vga none -device virtio-gpu-pci"
+
+    # Increase performance:
+    "-smp 8"
+  ];
+
+  environment.fortify = {
+    enable = true;
+    stateDir = "/var/lib/fortify";
+    users.alice = 0;
+
+    home-manager = _: _: { home.stateVersion = "23.05"; };
+
+    apps = with testCases; [
+      preset
+      tty
+      mapuid
+      device
+    ];
+  };
+}

test/sandbox/default.nix

@@ -1,14 +1,39 @@
 {
-  writeShellScript,
+  lib,
-  writeText,
+  nixosTest,
-  callPackage,
 
-  version,
+  self,
+  withRace ? false,
 }:
-name: want:
+
-writeShellScript "fortify-${name}-check-sandbox-script" ''
+nixosTest {
-  set -e
+  name = "fortify-sandbox" + (if withRace then "-race" else "");
-  ${callPackage ./assert.nix { inherit version; }}/bin/test \
+  nodes.machine =
-    ${writeText "fortify-${name}-want.json" (builtins.toJSON want)}
+    { options, pkgs, ... }:
-  touch /tmp/sandbox-ok
+    {
-''
+      # Run with Go race detector:
+      environment.fortify = lib.mkIf withRace rec {
+        # race detector does not support static linking
+        package = (pkgs.callPackage ../../package.nix { }).overrideAttrs (previousAttrs: {
+          GOFLAGS = previousAttrs.GOFLAGS ++ [ "-race" ];
+        });
+        fsuPackage = options.environment.fortify.fsuPackage.default.override { fortify = package; };
+      };
+
+      imports = [
+        ./configuration.nix
+
+        self.nixosModules.fortify
+        self.inputs.home-manager.nixosModules.home-manager
+      ];
+    };
+
+  # adapted from nixos sway integration tests
+
+  # testScriptWithTypes:49: error: Cannot call function of unknown type
+  #           (machine.succeed if succeed else machine.execute)(
+  #           ^
+  # Found 1 error in 1 file (checked 1 source file)
+  skipTypeCheck = true;
+  testScript = builtins.readFile ./test.py;
+}

test/sandbox/ptrace.go

@@ -0,0 +1,119 @@
+package sandbox
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"syscall"
+	"time"
+	"unsafe"
+)
+
+const (
+	NULL = 0
+
+	PTRACE_ATTACH             = 16
+	PTRACE_DETACH             = 17
+	PTRACE_SECCOMP_GET_FILTER = 0x420c
+)
+
+type ptraceError struct {
+	op    string
+	errno syscall.Errno
+}
+
+func (p *ptraceError) Error() string { return fmt.Sprintf("%s: %v", p.op, p.errno) }
+
+func (p *ptraceError) Unwrap() error {
+	if p.errno == 0 {
+		return nil
+	}
+	return p.errno
+}
+
+func ptrace(op uintptr, pid, addr int, data unsafe.Pointer) (r uintptr, errno syscall.Errno) {
+	r, _, errno = syscall.Syscall6(syscall.SYS_PTRACE, op, uintptr(pid), uintptr(addr), uintptr(data), NULL, NULL)
+	return
+}
+
+func ptraceAttach(pid int) error {
+	const (
+		statePrefix = "State:"
+		stateSuffix = "t (tracing stop)"
+	)
+
+	var r io.ReadSeekCloser
+	if f, err := os.Open(fmt.Sprintf("/proc/%d/status", pid)); err != nil {
+		return err
+	} else {
+		r = f
+	}
+
+	if _, errno := ptrace(PTRACE_ATTACH, pid, 0, nil); errno != 0 {
+		return &ptraceError{"PTRACE_ATTACH", errno}
+	}
+
+	// ugly! but there does not appear to be another way
+	for {
+		time.Sleep(10 * time.Millisecond)
+
+		if _, err := r.Seek(0, io.SeekStart); err != nil {
+			return err
+		}
+		s := bufio.NewScanner(r)
+
+		var found bool
+		for s.Scan() {
+			found = strings.HasPrefix(s.Text(), statePrefix)
+			if found {
+				break
+			}
+		}
+		if err := s.Err(); err != nil {
+			return err
+		}
+
+		if !found {
+			return syscall.EBADE
+		}
+
+		if strings.HasSuffix(s.Text(), stateSuffix) {
+			break
+		}
+	}
+
+	return nil
+}
+
+func ptraceDetach(pid int) error {
+	if _, errno := ptrace(PTRACE_DETACH, pid, 0, nil); errno != 0 {
+		return &ptraceError{"PTRACE_DETACH", errno}
+	}
+	return nil
+}
+
+type sockFilter struct { /* Filter block */
+	code uint16 /* Actual filter code */
+	jt   uint8  /* Jump true */
+	jf   uint8  /* Jump false */
+	k    uint32 /* Generic multiuse field */
+}
+
+func getFilter[T comparable](pid, index int) ([]T, error) {
+	if s := unsafe.Sizeof(*new(T)); s != 8 {
+		panic(fmt.Sprintf("invalid filter block size %d", s))
+	}
+
+	var buf []T
+	if n, errno := ptrace(PTRACE_SECCOMP_GET_FILTER, pid, index, nil); errno != 0 {
+		return nil, &ptraceError{"PTRACE_SECCOMP_GET_FILTER", errno}
+	} else {
+		buf = make([]T, n)
+	}
+	if _, errno := ptrace(PTRACE_SECCOMP_GET_FILTER, pid, index, unsafe.Pointer(&buf[0])); errno != 0 {
+		return nil, &ptraceError{"PTRACE_SECCOMP_GET_FILTER", errno}
+	}
+	return buf, nil
+}

test/sandbox/seccomp.go

@@ -10,9 +10,7 @@ import (
 */
 import "C"
 
-const NULL = 0
+func trySyscalls() error {
-
-func TrySyscalls() error {
 	testCases := []struct {
 		name  string
 		errno syscall.Errno

test/sandbox/test.py

@@ -0,0 +1,72 @@
+import json
+import shlex
+
+q = shlex.quote
+
+
+def swaymsg(command: str = "", succeed=True, type="command"):
+    assert command != "" or type != "command", "Must specify command or type"
+    shell = q(f"swaymsg -t {q(type)} -- {q(command)}")
+    with machine.nested(
+            f"sending swaymsg {shell!r}" + " (allowed to fail)" * (not succeed)
+    ):
+        ret = (machine.succeed if succeed else machine.execute)(
+            f"su - alice -c {shell}"
+        )
+
+    # execute also returns a status code, but disregard.
+    if not succeed:
+        _, ret = ret
+
+    if not succeed and not ret:
+        return None
+
+    parsed = json.loads(ret)
+    return parsed
+
+
+start_all()
+machine.wait_for_unit("multi-user.target")
+
+# To check fortify's version:
+print(machine.succeed("sudo -u alice -i fortify version"))
+
+# Wait for Sway to complete startup:
+machine.wait_for_file("/run/user/1000/wayland-1")
+machine.wait_for_file("/tmp/sway-ipc.sock")
+
+# Check seccomp outcome:
+swaymsg("exec fortify run cat")
+pid = int(machine.wait_until_succeeds("pgrep -U 1000000 -x cat", timeout=5))
+print(machine.succeed(f"fortify-test filter {pid} c698b081ff957afe17a6d94374537d37f2a63f6f9dd75da7546542407a9e32476ebda3312ba7785d7f618542bcfaf27ca27dcc2dddba852069d28bcfe8cad39a &>/dev/stdout", timeout=5))
+machine.succeed(f"kill -TERM {pid}")
+
+# Verify capabilities/securebits in user namespace:
+print(machine.succeed("sudo -u alice -i fortify run capsh --print"))
+print(machine.succeed("sudo -u alice -i fortify run capsh --has-no-new-privs"))
+print(machine.fail("sudo -u alice -i fortify run capsh --has-a=CAP_SYS_ADMIN"))
+print(machine.fail("sudo -u alice -i fortify run capsh --has-b=CAP_SYS_ADMIN"))
+print(machine.fail("sudo -u alice -i fortify run capsh --has-i=CAP_SYS_ADMIN"))
+print(machine.fail("sudo -u alice -i fortify run capsh --has-p=CAP_SYS_ADMIN"))
+print(machine.fail("sudo -u alice -i fortify run umount -R /dev"))
+
+# Check sandbox outcome:
+check_offset = 0
+def check_sandbox(name):
+    global check_offset
+    check_offset += 1
+    swaymsg(f"exec script /dev/null -E always -qec check-sandbox-{name}")
+    machine.wait_for_file(f"/tmp/fortify.1000/tmpdir/{check_offset}/sandbox-ok", timeout=15)
+
+
+check_sandbox("preset")
+check_sandbox("tty")
+check_sandbox("mapuid")
+check_sandbox("device")
+
+# Exit Sway and verify process exit status 0:
+swaymsg("exit", succeed=False)
+machine.wait_for_file("/tmp/sway-exit-ok")
+
+# Print fortify runDir contents:
+print(machine.succeed("find /run/user/1000/fortify"))

test/sandbox/tool/main.go

@@ -0,0 +1,39 @@
+package main
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"strings"
+
+	"git.gensokyo.uk/security/fortify/test/sandbox"
+)
+
+func main() {
+	log.SetFlags(0)
+	log.SetPrefix("test: ")
+
+	if len(os.Args) < 2 {
+		log.Fatal("invalid argument")
+	}
+
+	switch os.Args[1] {
+	case "filter":
+		if len(os.Args) != 4 {
+			log.Fatal("invalid argument")
+		}
+
+		if pid, err := strconv.Atoi(strings.TrimSpace(os.Args[2])); err != nil {
+			log.Fatalf("%s", err)
+		} else if pid < 1 {
+			log.Fatalf("%d out of range", pid)
+		} else {
+			sandbox.MustCheckFilter(pid, os.Args[3])
+			return
+		}
+
+	default:
+		(&sandbox.T{FS: os.DirFS("/")}).MustCheckFile(os.Args[1], "/tmp/sandbox-ok")
+		return
+	}
+}

test/sandbox/tool/package.nix

@@ -0,0 +1,30 @@
+{
+  lib,
+  buildGoModule,
+  pkg-config,
+  util-linux,
+
+  version,
+}:
+buildGoModule rec {
+  pname = "check-sandbox";
+  inherit version;
+
+  src = builtins.path {
+    name = "${pname}-src";
+    path = lib.cleanSource ../.;
+    filter = path: type: (type == "directory") || (type == "regular" && lib.hasSuffix ".go" path);
+  };
+  vendorHash = null;
+
+  buildInputs = [ util-linux ];
+  nativeBuildInputs = [ pkg-config ];
+
+  preBuild = ''
+    go mod init git.gensokyo.uk/security/fortify/test/sandbox >& /dev/null
+  '';
+
+  postInstall = ''
+    mv $out/bin/tool $out/bin/fortify-test
+  '';
+}

test/test.py

@@ -69,8 +69,8 @@ def check_state(name, enablements):
     if len(config['args']) != 1 or config['args'][0] != command:
         raise Exception(f"unexpected args {config['args']}")
 
-    if config['confinement']['enablements'] != enablements:
+    if config['enablements'] != enablements:
-        raise Exception(f"unexpected enablements {instance['config']['confinement']['enablements']}")
+        raise Exception(f"unexpected enablements {instance['config']['enablements']}")
 
 
 def fortify(command):
@@ -105,19 +105,9 @@ if denyOutput != "fsu: uid 1001 is not in the fsurc file\n":
 if denyOutputVerbose != "fsu: uid 1001 is not in the fsurc file\nfortify: *cannot obtain uid from fsu: permission denied\n":
     raise Exception(f"unexpected deny verbose output:\n{denyOutputVerbose}")
 
-# Check sandbox outcome:
 check_offset = 0
-def check_sandbox(name):
-    global check_offset
-    check_offset += 1
-    swaymsg(f"exec script /dev/null -E always -qec check-sandbox-{name}")
-    machine.wait_for_file(f"/tmp/fortify.1000/tmpdir/{check_offset}/sandbox-ok", timeout=15)
 
 
-check_sandbox("preset")
-check_sandbox("tty")
-check_sandbox("mapuid")
-
 def aid(offset):
     return 1+check_offset+offset
 
@@ -179,6 +169,16 @@ machine.send_chars("exit\n")
 machine.wait_for_file("/tmp/p0-exit-ok", timeout=15)
 machine.fail("getfacl --absolute-names --omit-header --numeric /run/user/1000 | grep 1000000")
 
+# Check interrupt shim behaviour:
+swaymsg("exec sh -c 'ne-foot; echo -n $? > /tmp/monitor-exit-code'")
+wait_for_window(f"u0_a{aid(0)}@machine")
+machine.succeed("pkill -INT -f 'fortify -v app '")
+machine.wait_until_fails("pgrep foot", timeout=5)
+machine.wait_for_file("/tmp/monitor-exit-code")
+interrupt_exit_code = int(machine.succeed("cat /tmp/monitor-exit-code"))
+if interrupt_exit_code != 254:
+    raise Exception(f"unexpected exit code {interrupt_exit_code}")
+
 # Start app (foot) with Wayland enablement:
 swaymsg("exec ne-foot")
 wait_for_window(f"u0_a{aid(0)}@machine")
@@ -186,25 +186,11 @@ machine.send_chars("clear; wayland-info && touch /tmp/client-ok\n")
 machine.wait_for_file(tmpdir_path(0, "client-ok"), timeout=15)
 collect_state_ui("foot_wayland")
 check_state("ne-foot", 1)
-# Verify acl on XDG_RUNTIME_DIR:
+# Verify lack of acl on XDG_RUNTIME_DIR:
-print(machine.succeed(f"getfacl --absolute-names --omit-header --numeric /run/user/1000 | grep {aid(0) + 1000000}"))
+machine.fail(f"getfacl --absolute-names --omit-header --numeric /run/user/1000 | grep {aid(0) + 1000000}")
 machine.send_chars("exit\n")
 machine.wait_until_fails("pgrep foot", timeout=5)
-# Verify acl cleanup on XDG_RUNTIME_DIR:
+machine.fail(f"getfacl --absolute-names --omit-header --numeric /run/user/1000 | grep {aid(0) + 1000000}", timeout=5)
-machine.wait_until_fails(f"getfacl --absolute-names --omit-header --numeric /run/user/1000 | grep {aid(0) + 1000000}", timeout=5)
-
-# Start app (foot) with Wayland enablement from a terminal:
-swaymsg("exec foot $SHELL -c '(ne-foot) & sleep 1 && fortify show $(fortify ps --short) && touch /tmp/ps-show-ok && cat'")
-wait_for_window(f"u0_a{aid(0)}@machine")
-machine.send_chars("clear; wayland-info && touch /tmp/term-ok\n")
-machine.wait_for_file(tmpdir_path(0, "term-ok"), timeout=15)
-machine.wait_for_file("/tmp/ps-show-ok", timeout=5)
-collect_state_ui("foot_wayland_term")
-check_state("ne-foot", 1)
-machine.send_chars("exit\n")
-wait_for_window("foot")
-machine.send_key("ctrl-c")
-machine.wait_until_fails("pgrep foot", timeout=5)
 
 # Test PulseAudio (fortify does not support PipeWire yet):
 swaymsg("exec pa-foot")
@@ -243,6 +229,22 @@ machine.wait_until_fails(f"getfacl --absolute-names --omit-header --numeric /run
 # Test syscall filter:
 print(machine.fail("sudo -u alice -i XDG_RUNTIME_DIR=/run/user/1000 strace-failure"))
 
+# Start app (foot) with Wayland enablement from a terminal:
+swaymsg("exec foot $SHELL -c '(ne-foot) & disown && exec $SHELL'")
+wait_for_window(f"u0_a{aid(0)}@machine")
+machine.send_chars("clear; wayland-info && touch /tmp/term-ok\n")
+machine.wait_for_file(tmpdir_path(0, "term-ok"), timeout=15)
+machine.send_key("alt-h")
+machine.send_chars("clear; fortify show $(fortify ps --short) && touch /tmp/ps-show-ok && exec cat\n")
+machine.wait_for_file("/tmp/ps-show-ok", timeout=5)
+collect_state_ui("foot_wayland_term")
+check_state("ne-foot", 1)
+machine.send_key("alt-l")
+machine.send_chars("exit\n")
+wait_for_window("alice@machine")
+machine.send_key("ctrl-c")
+machine.wait_until_fails("pgrep foot", timeout=5)
+
 # Exit Sway and verify process exit status 0:
 swaymsg("exit", succeed=False)
 machine.wait_for_file("/tmp/sway-exit-ok")