internal/app/outcome: apply configured filesystems late

This enables configured filesystems to cover system mount points.

Closes #8.

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

cmd/hakurei/command.go

@@ -94,7 +94,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				passwd     *user.User
 				passwdOnce sync.Once
 				passwdFunc = func() {
-					us := strconv.Itoa(app.HsuUid(new(app.Hsu).MustIDMsg(msg), flagIdentity))
+					us := strconv.Itoa(app.HsuUid(new(app.Hsu).MustID(msg), flagIdentity))
 					if u, err := user.LookupId(us); err != nil {
 						msg.Verbosef("cannot look up uid %s", us)
 						passwd = &user.User{
@@ -302,7 +302,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 		var flagShort bool
 		c.NewCommand("ps", "List active instances", func(args []string) error {
 			var sc hst.Paths
-			app.CopyPaths().Copy(&sc, new(app.Hsu).MustID())
+			app.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
 			printPs(os.Stdout, time.Now().UTC(), state.NewMulti(msg, sc.RunDirPath.String()), flagShort, flagJSON)
 			return errSuccess
 		}).Flag(&flagShort, "short", command.BoolFlag(false), "Print instance id")

cmd/hakurei/parse.go

@@ -89,7 +89,7 @@ func tryShort(msg message.Msg, name string) (config *hst.Config, entry *state.St
 		msg.Verbose("argument looks like prefix")
 
 		var sc hst.Paths
-		app.CopyPaths().Copy(&sc, new(app.Hsu).MustID())
+		app.CopyPaths().Copy(&sc, new(app.Hsu).MustID(nil))
 		s := state.NewMulti(msg, sc.RunDirPath.String())
 		if entries, err := state.Join(s); err != nil {
 			log.Printf("cannot join store: %v", err)

cmd/hakurei/print.go

@@ -21,7 +21,7 @@ func printShowSystem(output io.Writer, short, flagJSON bool) {
 	t := newPrinter(output)
 	defer t.MustFlush()
 
-	info := &hst.Info{User: new(app.Hsu).MustID()}
+	info := &hst.Info{User: new(app.Hsu).MustID(nil)}
 	app.CopyPaths().Copy(&info.Paths, info.User)
 
 	if flagJSON {

container/init.go

@@ -353,10 +353,14 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		wpid    int
 		wstatus WaitStatus
 	}
+
+	// info is closed as the wait4 thread terminates
+	// when there are no longer any processes left to reap
 	info := make(chan winfo, 1)
-	done := make(chan struct{})
 
 	k.new(func(k syscallDispatcher) {
+		k.lockOSThread()
+
 		var (
 			err     error
 			wpid    = -2
@@ -382,7 +386,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 			k.printf(msg, "unexpected wait4 response: %v", err)
 		}
 
-		close(done)
+		close(info)
 	})
 
 	// handle signals to dump withheld messages
@@ -411,7 +415,13 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 			msg.BeforeExit()
 			k.exit(0)
 
-		case w := <-info:
+		case w, ok := <-info:
+			if !ok {
+				msg.BeforeExit()
+				k.exit(r)
+				continue // unreachable
+			}
+
 			if w.wpid == cmd.Process.Pid {
 				// initial process exited, output is most likely available again
 				msg.Resume()
@@ -433,10 +443,6 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 				go func() { time.Sleep(params.AdoptWaitDelay); close(timeout) }()
 			}
 
-		case <-done:
-			msg.BeforeExit()
-			k.exit(r)
-
 		case <-timeout:
 			k.printf(msg, "timeout exceeded waiting for lingering processes")
 			msg.BeforeExit()

container/init_test.go

@@ -2081,6 +2081,8 @@ func TestInitEntrypoint(t *testing.T) {
 
 			/* wait4 */
 			Tracks: []stub.Expect{{Calls: []stub.Call{
+				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
+
 				// magicWait4Signal as args[4] causes this to block until simulated signal is delivered
 				call("wait4", stub.ExpectArgs{-1, syscall.WaitStatus(0xfade01ce), 0, nil, magicWait4Signal}, 0xbad, nil),
 				// this terminates the goroutine at the call, preventing it from leaking while preserving behaviour
@@ -2174,6 +2176,8 @@ func TestInitEntrypoint(t *testing.T) {
 
 			/* wait4 */
 			Tracks: []stub.Expect{{Calls: []stub.Call{
+				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
+
 				// this terminates the goroutine at the call, preventing it from leaking while preserving behaviour
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil, stub.PanicExit}, 0, syscall.ECHILD),
 			}}},
@@ -2266,6 +2270,8 @@ func TestInitEntrypoint(t *testing.T) {
 
 			/* wait4 */
 			Tracks: []stub.Expect{{Calls: []stub.Call{
+				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
+
 				call("wait4", stub.ExpectArgs{-1, syscall.WaitStatus(0xfade01ce), 0, nil}, 0xbad, nil),
 				// this terminates the goroutine at the call, preventing it from leaking while preserving behaviour
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil, 0xdeadbeef}, 0, syscall.ECHILD),
@@ -2358,6 +2364,8 @@ func TestInitEntrypoint(t *testing.T) {
 
 			/* wait4 */
 			Tracks: []stub.Expect{{Calls: []stub.Call{
+				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
+
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil}, 0, syscall.EINTR),
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil}, 0, syscall.EINTR),
 				call("wait4", stub.ExpectArgs{-1, syscall.WaitStatus(0xdeaf), 0, nil}, 0xbabe, nil),
@@ -2494,6 +2502,8 @@ func TestInitEntrypoint(t *testing.T) {
 
 			/* wait4 */
 			Tracks: []stub.Expect{{Calls: []stub.Call{
+				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
+
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil}, 0, syscall.EINTR),
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil}, 0, syscall.EINTR),
 				call("wait4", stub.ExpectArgs{-1, syscall.WaitStatus(0xdeaf), 0, nil}, 0xbabe, nil),
@@ -2634,6 +2644,8 @@ func TestInitEntrypoint(t *testing.T) {
 
 			/* wait4 */
 			Tracks: []stub.Expect{{Calls: []stub.Call{
+				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
+
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil}, 0, syscall.EINTR),
 				call("wait4", stub.ExpectArgs{-1, nil, 0, nil}, 0, syscall.EINTR),
 				call("wait4", stub.ExpectArgs{-1, syscall.WaitStatus(0xdeaf), 0, nil}, 0xbabe, nil),

hst/container.go

@@ -24,18 +24,25 @@ const (
 	IdentityMin = 0
 	// IdentityMax is the maximum value of [Config.Identity]. This is enforced by cmd/hsu.
 	IdentityMax = 9999
+)
 
-	// ShimExitRequest is returned when the priv side process requests shim exit.
-	ShimExitRequest = 254
-	// ShimExitOrphan is returned when the shim is orphaned before priv side delivers a signal.
-	ShimExitOrphan = 3
+const (
+	// ExitFailure is returned if the container fails to start.
+	ExitFailure = iota + 1
+	// ExitCancel is returned if the container is terminated by a shim-directed signal which cancels its context.
+	ExitCancel
+	// ExitOrphan is returned when the shim is orphaned before priv side delivers a signal.
+	ExitOrphan
+
+	// ExitRequest is returned when the priv side process requests shim exit.
+	ExitRequest = 254
 )
 
 const (
 	// FMultiarch unblocks syscalls required for multiarch to work on applicable targets.
 	FMultiarch uintptr = 1 << iota
 
-	// FSeccompCompat causes emitted seccomp filter programs to be identical to Flatpak.
+	// FSeccompCompat changes emitted seccomp filter programs to be identical to that of Flatpak.
 	FSeccompCompat
 	// FDevel unblocks ptrace and friends.
 	FDevel

internal/app/app_test.go

@@ -103,17 +103,17 @@ func TestApp(t *testing.T) {
 					Tmpfs(hst.AbsPrivateTmp, 4096, 0755).
 					DevWritable(m("/dev/"), true).
 					Tmpfs(m("/dev/shm"), 0, 01777).
+					Tmpfs(m("/run/user/"), 4096, 0755).
+					Bind(m("/tmp/hakurei.0/runtime/0"), m("/run/user/65534"), bits.BindWritable).
+					Bind(m("/tmp/hakurei.0/tmpdir/0"), m("/tmp/"), bits.BindWritable).
+					Place(m("/etc/passwd"), []byte("chronos:x:65534:65534:Hakurei:/home/chronos:/run/current-system/sw/bin/zsh\n")).
+					Place(m("/etc/group"), []byte("hakurei:x:65534:\n")).
 					Bind(m("/dev/kvm"), m("/dev/kvm"), bits.BindWritable|bits.BindDevice|bits.BindOptional).
 					Etc(m("/etc/"), "4a450b6596d7bc15bd01780eb9a607ac").
 					Tmpfs(m("/run/user/1971"), 8192, 0755).
 					Tmpfs(m("/run/nscd"), 8192, 0755).
 					Tmpfs(m("/run/dbus"), 8192, 0755).
 					Remount(m("/dev/"), syscall.MS_RDONLY).
-					Tmpfs(m("/run/user/"), 4096, 0755).
-					Bind(m("/tmp/hakurei.0/runtime/0"), m("/run/user/65534"), bits.BindWritable).
-					Bind(m("/tmp/hakurei.0/tmpdir/0"), m("/tmp/"), bits.BindWritable).
-					Place(m("/etc/passwd"), []byte("chronos:x:65534:65534:Hakurei:/home/chronos:/run/current-system/sw/bin/zsh\n")).
-					Place(m("/etc/group"), []byte("hakurei:x:65534:\n")).
 					Remount(m("/"), syscall.MS_RDONLY),
 				SeccompPresets: bits.PresetExt | bits.PresetDenyDevel,
 				HostNet:        true,
@@ -268,7 +268,7 @@ func TestApp(t *testing.T) {
 					"WAYLAND_DISPLAY=wayland-0",
 					"XDG_RUNTIME_DIR=/run/user/65534",
 					"XDG_SESSION_CLASS=user",
-					"XDG_SESSION_TYPE=tty",
+					"XDG_SESSION_TYPE=wayland",
 				},
 				Ops: new(container.Ops).
 					Root(m("/"), bits.BindWritable).
@@ -276,13 +276,6 @@ func TestApp(t *testing.T) {
 					Tmpfs(hst.AbsPrivateTmp, 4096, 0755).
 					DevWritable(m("/dev/"), true).
 					Tmpfs(m("/dev/shm"), 0, 01777).
-					Bind(m("/dev/dri"), m("/dev/dri"), bits.BindWritable|bits.BindDevice|bits.BindOptional).
-					Bind(m("/dev/kvm"), m("/dev/kvm"), bits.BindWritable|bits.BindDevice|bits.BindOptional).
-					Etc(m("/etc/"), "ebf083d1b175911782d413369b64ce7c").
-					Tmpfs(m("/run/user/1971"), 8192, 0755).
-					Tmpfs(m("/run/nscd"), 8192, 0755).
-					Tmpfs(m("/run/dbus"), 8192, 0755).
-					Remount(m("/dev/"), syscall.MS_RDONLY).
 					Tmpfs(m("/run/user/"), 4096, 0755).
 					Bind(m("/tmp/hakurei.0/runtime/9"), m("/run/user/65534"), bits.BindWritable).
 					Bind(m("/tmp/hakurei.0/tmpdir/9"), m("/tmp/"), bits.BindWritable).
@@ -293,6 +286,13 @@ func TestApp(t *testing.T) {
 					Place(m(hst.PrivateTmp+"/pulse-cookie"), bytes.Repeat([]byte{0}, pulseCookieSizeMax)).
 					Bind(m("/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/bus"), m("/run/user/65534/bus"), 0).
 					Bind(m("/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/system_bus_socket"), m("/var/run/dbus/system_bus_socket"), 0).
+					Bind(m("/dev/dri"), m("/dev/dri"), bits.BindWritable|bits.BindDevice|bits.BindOptional).
+					Bind(m("/dev/kvm"), m("/dev/kvm"), bits.BindWritable|bits.BindDevice|bits.BindOptional).
+					Etc(m("/etc/"), "ebf083d1b175911782d413369b64ce7c").
+					Tmpfs(m("/run/user/1971"), 8192, 0755).
+					Tmpfs(m("/run/nscd"), 8192, 0755).
+					Tmpfs(m("/run/dbus"), 8192, 0755).
+					Remount(m("/dev/"), syscall.MS_RDONLY).
 					Remount(m("/"), syscall.MS_RDONLY),
 				SeccompPresets: bits.PresetExt | bits.PresetDenyDevel,
 				HostNet:        true,
@@ -420,13 +420,23 @@ func TestApp(t *testing.T) {
 					"WAYLAND_DISPLAY=wayland-0",
 					"XDG_RUNTIME_DIR=/run/user/1971",
 					"XDG_SESSION_CLASS=user",
-					"XDG_SESSION_TYPE=tty",
+					"XDG_SESSION_TYPE=wayland",
 				},
 				Ops: new(container.Ops).
 					Proc(m("/proc/")).
 					Tmpfs(hst.AbsPrivateTmp, 4096, 0755).
 					DevWritable(m("/dev/"), true).
 					Tmpfs(m("/dev/shm"), 0, 01777).
+					Tmpfs(m("/run/user/"), 4096, 0755).
+					Bind(m("/tmp/hakurei.0/runtime/1"), m("/run/user/1971"), bits.BindWritable).
+					Bind(m("/tmp/hakurei.0/tmpdir/1"), m("/tmp/"), bits.BindWritable).
+					Place(m("/etc/passwd"), []byte("u0_a1:x:1971:100:Hakurei:/var/lib/persist/module/hakurei/0/1:/run/current-system/sw/bin/zsh\n")).
+					Place(m("/etc/group"), []byte("hakurei:x:100:\n")).
+					Bind(m("/run/user/1971/wayland-0"), m("/run/user/1971/wayland-0"), 0).
+					Bind(m("/run/user/1971/hakurei/8e2c76b066dabe574cf073bdb46eb5c1/pulse"), m("/run/user/1971/pulse/native"), 0).
+					Place(m(hst.PrivateTmp+"/pulse-cookie"), bytes.Repeat([]byte{0}, pulseCookieSizeMax)).
+					Bind(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/bus"), m("/run/user/1971/bus"), 0).
+					Bind(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket"), m("/var/run/dbus/system_bus_socket"), 0).
 					Bind(m("/bin"), m("/bin"), 0).
 					Bind(m("/usr/bin/"), m("/usr/bin/"), 0).
 					Bind(m("/nix/store"), m("/nix/store"), 0).
@@ -441,16 +451,6 @@ func TestApp(t *testing.T) {
 					Etc(m("/etc/"), "8e2c76b066dabe574cf073bdb46eb5c1").
 					Bind(m("/var/lib/persist/module/hakurei/0/1"), m("/var/lib/persist/module/hakurei/0/1"), bits.BindWritable|bits.BindEnsure).
 					Remount(m("/dev/"), syscall.MS_RDONLY).
-					Tmpfs(m("/run/user/"), 4096, 0755).
-					Bind(m("/tmp/hakurei.0/runtime/1"), m("/run/user/1971"), bits.BindWritable).
-					Bind(m("/tmp/hakurei.0/tmpdir/1"), m("/tmp/"), bits.BindWritable).
-					Place(m("/etc/passwd"), []byte("u0_a1:x:1971:100:Hakurei:/var/lib/persist/module/hakurei/0/1:/run/current-system/sw/bin/zsh\n")).
-					Place(m("/etc/group"), []byte("hakurei:x:100:\n")).
-					Bind(m("/run/user/1971/wayland-0"), m("/run/user/1971/wayland-0"), 0).
-					Bind(m("/run/user/1971/hakurei/8e2c76b066dabe574cf073bdb46eb5c1/pulse"), m("/run/user/1971/pulse/native"), 0).
-					Place(m(hst.PrivateTmp+"/pulse-cookie"), bytes.Repeat([]byte{0}, pulseCookieSizeMax)).
-					Bind(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/bus"), m("/run/user/1971/bus"), 0).
-					Bind(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket"), m("/var/run/dbus/system_bus_socket"), 0).
 					Remount(m("/"), syscall.MS_RDONLY),
 				SeccompPresets: bits.PresetExt | bits.PresetDenyTTY | bits.PresetDenyDevel,
 				HostNet:        true,

internal/app/dispatcher_test.go

@@ -2,8 +2,10 @@ package app
 
 import (
 	"bytes"
+	"io"
 	"io/fs"
 	"log"
+	"maps"
 	"os"
 	"os/exec"
 	"reflect"
@@ -26,33 +28,135 @@ func call(name string, args stub.ExpectArgs, ret any, err error) stub.Call {
 	return stub.Call{Name: name, Args: args, Ret: ret, Err: err}
 }
 
-// checkExpectUid is the uid value used by checkOpBehaviour to initialise [system.I].
-const checkExpectUid = 0xcafebabe
+const (
+	// checkExpectUid is the uid value used by checkOpBehaviour to initialise [system.I].
+	checkExpectUid = 0xcafebabe
+	// wantAutoEtcPrefix is the autoetc prefix corresponding to checkExpectInstanceId.
+	wantAutoEtcPrefix = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+	// wantInstancePrefix is the SharePath corresponding to checkExpectInstanceId.
+	wantInstancePrefix = container.Nonexistent + "/tmp/hakurei.0/" + wantAutoEtcPrefix
 
-// wantAutoEtcPrefix is the autoetc prefix corresponding to checkExpectInstanceId.
-const wantAutoEtcPrefix = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+	// wantRuntimePath is the XDG_RUNTIME_DIR value returned during testing.
+	wantRuntimePath = "/proc/nonexistent/xdg_runtime_dir"
+	// wantRunDirPath is the RunDirPath value resolved during testing.
+	wantRunDirPath = wantRuntimePath + "/hakurei"
+	// wantRuntimeSharePath is the runtimeSharePath value resolved during testing.
+	wantRuntimeSharePath = wantRunDirPath + "/aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
+)
 
 // checkExpectInstanceId is the [state.ID] value used by checkOpBehaviour to initialise outcomeState.
 var checkExpectInstanceId = *(*state.ID)(bytes.Repeat([]byte{0xaa}, len(state.ID{})))
 
+type (
+	// pStateSysFunc is called before each test case is run to prepare outcomeStateSys.
+	pStateSysFunc = func(state *outcomeStateSys)
+	// pStateContainerFunc is called before each test case is run to prepare outcomeStateParams.
+	pStateContainerFunc = func(state *outcomeStateParams)
+
+	// extraCheckSysFunc is called to check outcomeStateSys and must not have side effects.
+	extraCheckSysFunc = func(t *testing.T, state *outcomeStateSys)
+	// extraCheckParamsFunc is called to check outcomeStateParams and must not have side effects.
+	extraCheckParamsFunc = func(t *testing.T, state *outcomeStateParams)
+)
+
+// insertsOps prepares outcomeStateParams to allow [container.Op] to be inserted.
+func insertsOps(next pStateContainerFunc) pStateContainerFunc {
+	return func(state *outcomeStateParams) {
+		state.params.Ops = new(container.Ops)
+
+		if next != nil {
+			next(state)
+		}
+	}
+}
+
+// afterSpRuntimeOp prepares outcomeStateParams for an outcomeOp meant to run after spRuntimeOp.
+func afterSpRuntimeOp(next pStateContainerFunc) pStateContainerFunc {
+	return func(state *outcomeStateParams) {
+		// emulates spRuntimeOp
+		state.runtimeDir = m("/run/user/1000")
+
+		if next != nil {
+			next(state)
+		}
+	}
+}
+
+// sysUsesInstance checks for use of the outcomeStateSys.instance method.
+func sysUsesInstance(next extraCheckSysFunc) extraCheckSysFunc {
+	return func(t *testing.T, state *outcomeStateSys) {
+		if want := m(wantInstancePrefix); !reflect.DeepEqual(state.sharePath, want) {
+			t.Errorf("outcomeStateSys: sharePath = %v, want %v", state.sharePath, want)
+		}
+
+		if next != nil {
+			next(t, state)
+		}
+	}
+}
+
+// sysUsesRuntime checks for use of the outcomeStateSys.runtime method.
+func sysUsesRuntime(next extraCheckSysFunc) extraCheckSysFunc {
+	return func(t *testing.T, state *outcomeStateSys) {
+		if want := m(wantRuntimeSharePath); !reflect.DeepEqual(state.runtimeSharePath, want) {
+			t.Errorf("outcomeStateSys: runtimeSharePath = %v, want %v", state.runtimeSharePath, want)
+		}
+
+		if next != nil {
+			next(t, state)
+		}
+	}
+}
+
+// paramsWantEnv checks outcomeStateParams.env for inserted entries on top of [hst.Config].
+func paramsWantEnv(config *hst.Config, wantEnv map[string]string, next extraCheckParamsFunc) extraCheckParamsFunc {
+	want := make(map[string]string, len(wantEnv)+len(config.Container.Env))
+	maps.Copy(want, wantEnv)
+	maps.Copy(want, config.Container.Env)
+	return func(t *testing.T, state *outcomeStateParams) {
+		if !maps.Equal(state.env, want) {
+			t.Errorf("toContainer: env = %#v, want %#v", state.env, want)
+		}
+
+		if next != nil {
+			next(t, state)
+		}
+	}
+}
+
+// opBehaviourTestCase checks outcomeOp behaviour against outcomeStateSys and outcomeStateParams.
 type opBehaviourTestCase struct {
-	name      string
-	newOp     func(isShim, clearUnexported bool) outcomeOp
+	name string
+	// newOp returns a new instance of outcomeOp under testing that is safe to clobber.
+	newOp func(isShim, clearUnexported bool) outcomeOp
+	// newConfig returns a new instance of [hst.Config] that is checked not to be clobbered by outcomeOp.
 	newConfig func() *hst.Config
 
-	pStateSys     func(state *outcomeStateSys)
-	toSystem      []stub.Call
-	wantSys       *system.I
-	extraCheckSys func(t *testing.T, state *outcomeStateSys)
+	// pStateSys is called before outcomeOp.toSystem to prepare outcomeStateSys.
+	pStateSys pStateSysFunc
+	// toSystem are expected syscallDispatcher calls during outcomeOp.toSystem.
+	toSystem []stub.Call
+	// wantSys is the expected [system.I] state after outcomeOp.toSystem.
+	wantSys *system.I
+	// extraCheckSys is called after outcomeOp.toSystem to check the state of outcomeStateSys.
+	extraCheckSys extraCheckSysFunc
+	// wantErrSystem is the expected error value returned by outcomeOp.toSystem.
+	// Further testing is skipped if not nil.
 	wantErrSystem error
 
-	pStateContainer  func(state *outcomeStateParams)
-	toContainer      []stub.Call
-	wantParams       *container.Params
-	extraCheckParams func(t *testing.T, state *outcomeStateParams)
+	// pStateContainer is called before outcomeOp.toContainer to prepare outcomeStateParams.
+	pStateContainer pStateContainerFunc
+	// toContainer are expected syscallDispatcher calls during outcomeOp.toContainer.
+	toContainer []stub.Call
+	// wantParams is the expected [container.Params] after outcomeOp.toContainer.
+	wantParams *container.Params
+	// extraCheckParams is called after outcomeOp.toContainer to check the state of outcomeStateParams.
+	extraCheckParams extraCheckParamsFunc
+	// wantErrContainer is the expected error value returned by outcomeOp.toContainer.
 	wantErrContainer error
 }
 
+// checkOpBehaviour runs a slice of opBehaviourTestCase.
 func checkOpBehaviour(t *testing.T, testCases []opBehaviourTestCase) {
 	t.Helper()
 
@@ -63,7 +167,7 @@ func checkOpBehaviour(t *testing.T, testCases []opBehaviourTestCase) {
 		call("mustHsuPath", stub.ExpectArgs{}, m(container.Nonexistent), nil),
 		call("cmdOutput", stub.ExpectArgs{container.Nonexistent, os.Stderr, []string{}, "/"}, []byte("0"), nil),
 		call("tempdir", stub.ExpectArgs{}, container.Nonexistent+"/tmp", nil),
-		call("lookupEnv", stub.ExpectArgs{"XDG_RUNTIME_DIR"}, container.Nonexistent+"/xdg_runtime_dir", nil),
+		call("lookupEnv", stub.ExpectArgs{"XDG_RUNTIME_DIR"}, wantRuntimePath, nil),
 		call("getuid", stub.ExpectArgs{}, 1000, nil),
 		call("getgid", stub.ExpectArgs{}, 100, nil),
 
@@ -169,6 +273,40 @@ func checkOpBehaviour(t *testing.T, testCases []opBehaviourTestCase) {
 
 func newI() *system.I { return system.New(panicMsgContext{}, panicMsgContext{}, checkExpectUid) }
 
+// simpleTestCase is a simple freeform test case utilising kstub.
+type simpleTestCase struct {
+	name string
+	f    func(k *kstub) error
+	// want are expected syscallDispatcher calls during f.
+	want stub.Expect
+	// wantErr is the expected error value returned by f.
+	wantErr error
+}
+
+// checkSimple runs a slice of simpleTestCase.
+func checkSimple(t *testing.T, fname string, testCases []simpleTestCase) {
+	t.Helper()
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Helper()
+			t.Parallel()
+
+			defer stub.HandleExit(t)
+			k := &kstub{panicDispatcher{}, stub.New(t, func(s *stub.Stub[syscallDispatcher]) syscallDispatcher { return &kstub{panicDispatcher{}, s} }, tc.want)}
+			if err := tc.f(k); !reflect.DeepEqual(err, tc.wantErr) {
+				t.Errorf("%s: error = %#v, want %#v", fname, err, tc.wantErr)
+			}
+			k.VisitIncomplete(func(s *stub.Stub[syscallDispatcher]) {
+				t.Helper()
+
+				t.Errorf("%s: %d calls, want %d", fname, s.Pos(), s.Len())
+			})
+		})
+	}
+}
+
+// kstub partially implements syscallDispatcher via [stub.Stub].
 type kstub struct {
 	panicDispatcher
 	*stub.Stub[syscallDispatcher]
@@ -189,6 +327,18 @@ func (k *kstub) lookupEnv(key string) (string, bool) {
 	}
 	return expect.Ret.(string), true
 }
+func (k *kstub) stat(name string) (os.FileInfo, error) {
+	k.Helper()
+	expect := k.Expects("stat")
+	return expect.Ret.(os.FileInfo), expect.Error(
+		stub.CheckArg(k.Stub, "name", name, 0))
+}
+func (k *kstub) open(name string) (osFile, error) {
+	k.Helper()
+	expect := k.Expects("open")
+	return expect.Ret.(osFile), expect.Error(
+		stub.CheckArg(k.Stub, "name", name, 0))
+}
 func (k *kstub) readdir(name string) ([]os.DirEntry, error) {
 	k.Helper()
 	expect := k.Expects("readdir")
@@ -272,6 +422,32 @@ func (k *kstub) Suspend() bool { k.Helper(); return k.Expects("suspend").Ret.(bo
 func (k *kstub) Resume() bool  { k.Helper(); return k.Expects("resume").Ret.(bool) }
 func (k *kstub) BeforeExit()   { k.Helper(); k.Expects("beforeExit") }
 
+// stubOsFile partially implements osFile.
+type stubOsFile struct {
+	closeErr error
+
+	io.Reader
+	io.Writer
+}
+
+func (f *stubOsFile) Close() error               { return f.closeErr }
+func (f *stubOsFile) Name() string               { panic("unreachable") }
+func (f *stubOsFile) Stat() (fs.FileInfo, error) { panic("unreachable") }
+
+// stubFi partially implements [os.FileInfo]. Can be passed as nil to assert all methods unreachable.
+type stubFi struct {
+	size  int64
+	mode  os.FileMode
+	isDir bool
+}
+
+func (fi *stubFi) Name() string       { panic("unreachable") }
+func (fi *stubFi) ModTime() time.Time { panic("unreachable") }
+func (fi *stubFi) Sys() any           { panic("unreachable") }
+func (fi *stubFi) Size() int64        { return fi.size }
+func (fi *stubFi) Mode() os.FileMode  { return fi.mode }
+func (fi *stubFi) IsDir() bool        { return fi.isDir }
+
 // stubDir returns a slice of [os.DirEntry] with only their Name method implemented.
 func stubDir(names ...string) []os.DirEntry {
 	d := make([]os.DirEntry, len(names))
@@ -289,6 +465,11 @@ func (nameDentry) IsDir() bool                { panic("unreachable") }
 func (nameDentry) Type() fs.FileMode          { panic("unreachable") }
 func (nameDentry) Info() (fs.FileInfo, error) { panic("unreachable") }
 
+// errorReader implements [io.Reader] that unconditionally returns -1, val.
+type errorReader struct{ val error }
+
+func (r errorReader) Read([]byte) (int, error) { return -1, r.val }
+
 // panicMsgContext implements [message.Msg] and [context.Context] with methods wrapping panic.
 // This should be assigned to test cases to be checked against.
 type panicMsgContext struct{}

internal/app/hsu.go

@@ -35,7 +35,8 @@ func (h *Hsu) ensureDispatcher() {
 	})
 }
 
-// ID returns the current user hsurc identifier. ErrHsuAccess is returned if the current user is not in hsurc.
+// ID returns the current user hsurc identifier.
+// [ErrHsuAccess] is returned if the current user is not in hsurc.
 func (h *Hsu) ID() (int, error) {
 	h.ensureDispatcher()
 	h.idOnce.Do(func() {
@@ -61,8 +62,8 @@ func (h *Hsu) ID() (int, error) {
 		} else if errors.As(h.idErr, &exitError) && exitError != nil && exitError.ExitCode() == 1 {
 			// hsu prints an error message in this case
 			h.idErr = &hst.AppError{Step: step, Err: ErrHsuAccess}
-		} else if os.IsNotExist(h.idErr) {
-			h.idErr = &hst.AppError{Step: step, Err: os.ErrNotExist,
+		} else if errors.Is(h.idErr, os.ErrNotExist) {
+			h.idErr = &hst.AppError{Step: step, Err: h.idErr,
 				Msg: fmt.Sprintf("the setuid helper is missing: %s", hsuPath)}
 		}
 	})
@@ -71,10 +72,7 @@ func (h *Hsu) ID() (int, error) {
 }
 
 // MustID calls [Hsu.ID] and terminates on error.
-func (h *Hsu) MustID() int { return h.MustIDMsg(nil) }
-
-// MustIDMsg implements MustID with a custom [container.Msg].
-func (h *Hsu) MustIDMsg(msg message.Msg) int {
+func (h *Hsu) MustID(msg message.Msg) int {
 	id, err := h.ID()
 	if err == nil {
 		return id
@@ -86,16 +84,16 @@ func (h *Hsu) MustIDMsg(msg message.Msg) int {
 			msg.Verbose("*"+fallback, err)
 		}
 		os.Exit(1)
-		return -0xdeadbeef
+		return -0xdeadbeef // not reached
 	} else if m, ok := message.GetMessage(err); ok {
 		log.Fatal(m)
-		return -0xdeadbeef
+		return -0xdeadbeef // not reached
 	} else {
 		log.Fatalln(fallback, err)
-		return -0xdeadbeef
+		return -0xdeadbeef // not reached
 	}
 }
 
 // HsuUid returns target uid for the stable hsu uid format.
-// No bounds check is performed, a value retrieved from hsu is expected.
+// No bounds check is performed, a value retrieved by [Hsu] is expected.
 func HsuUid(id, identity int) int { return 1000000 + id*10000 + identity }

internal/app/hsu_test.go

@@ -0,0 +1,84 @@
+package app
+
+import (
+	"os"
+	"os/exec"
+	"reflect"
+	"strconv"
+	"syscall"
+	"testing"
+	"unsafe"
+
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+)
+
+func TestHsu(t *testing.T) {
+	t.Parallel()
+
+	t.Run("ensure dispatcher", func(t *testing.T) {
+		hsu := new(Hsu)
+		hsu.ensureDispatcher()
+
+		k := direct{}
+		if !reflect.DeepEqual(hsu.k, k) {
+			t.Errorf("ensureDispatcher: k = %#v, want %#v", hsu.k, k)
+		}
+	})
+
+	fCheckID := func(k *kstub) error {
+		hsu := &Hsu{k: k}
+		id, err := hsu.ID()
+		k.Verbose(id)
+		if id0, err0 := hsu.ID(); id0 != id || !reflect.DeepEqual(err0, err) {
+			t.Fatalf("ID: id0 = %d, err0 = %#v, id = %d, err = %#v", id0, err0, id, err)
+		}
+		return err
+	}
+
+	checkSimple(t, "Hsu.ID", []simpleTestCase{
+		{"hsu nonexistent", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, ([]byte)(nil), os.ErrNotExist),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "obtain uid from hsu",
+			Err:  os.ErrNotExist,
+			Msg:  "the setuid helper is missing: /run/wrappers/bin/hsu",
+		}},
+
+		{"access", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, ([]byte)(nil), makeExitError(1<<8)),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "obtain uid from hsu",
+			Err:  ErrHsuAccess,
+		}},
+
+		{"invalid output", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, []byte{0}, nil),
+			call("verbose", stub.ExpectArgs{[]any{0}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "obtain uid from hsu",
+			Err:  &strconv.NumError{Func: "Atoi", Num: "\x00", Err: strconv.ErrSyntax},
+			Msg:  "invalid uid string from hsu",
+		}},
+
+		{"success", fCheckID, stub.Expect{Calls: []stub.Call{
+			call("mustHsuPath", stub.ExpectArgs{}, m("/run/wrappers/bin/hsu"), nil),
+			call("cmdOutput", stub.ExpectArgs{"/run/wrappers/bin/hsu", os.Stderr, []string{}, "/"}, []byte{'0'}, nil),
+			call("verbose", stub.ExpectArgs{[]any{0}}, nil, nil),
+		}}, nil},
+	})
+}
+
+// makeExitError populates syscall.WaitStatus in an [exec.ExitError].
+// Do not reuse this function in a cross-platform package.
+func makeExitError(status syscall.WaitStatus) error {
+	ps := new(os.ProcessState)
+	statusV := reflect.ValueOf(ps).Elem().FieldByName("status")
+	*reflect.NewAt(statusV.Type(), unsafe.Pointer(statusV.UnsafeAddr())).Interface().(*syscall.WaitStatus) = status
+	return &exec.ExitError{ProcessState: ps}
+}

internal/app/outcome.go

@@ -14,6 +14,10 @@ import (
 	"hakurei.app/system/acl"
 )
 
+// envAllocSize is the initial size of the env map pre-allocated when the configured env map is nil.
+// It should be large enough to fit all insertions by outcomeOp.toContainer.
+const envAllocSize = 1 << 6
+
 func newInt(v int) *stringPair[int] { return &stringPair[int]{v, strconv.Itoa(v)} }
 
 // stringPair stores a value and its string representation.
@@ -78,7 +82,7 @@ func newOutcomeState(k syscallDispatcher, msg message.Msg, id *state.ID, config
 		Shim:      &shimParams{PrivPID: k.getpid(), Verbose: msg.IsVerbose()},
 		ID:        id,
 		Identity:  config.Identity,
-		UserID:    hsu.MustIDMsg(msg),
+		UserID:    hsu.MustID(msg),
 		EnvPaths:  copyPaths(k),
 		Container: config.Container,
 	}
@@ -268,10 +272,7 @@ func (state *outcomeStateSys) toSystem() error {
 		// must run first
 		&spParamsOp{},
 
-		// TODO(ophestra): move this late for #8 and #9
-		&spFilesystemOp{},
-
-		spRuntimeOp{},
+		&spRuntimeOp{},
 		spTmpdirOp{},
 		spAccountOp{},
 
@@ -281,6 +282,7 @@ func (state *outcomeStateSys) toSystem() error {
 		&spPulseOp{},
 		&spDBusOp{},
 
+		&spFilesystemOp{},
 		spFinalOp{},
 	}
 

internal/app/shim.go

@@ -23,14 +23,11 @@ import (
 //#include "shim-signal.h"
 import "C"
 
-const (
-	// setup pipe fd for [container.Receive]
-	shimEnv = "HAKUREI_SHIM"
-
-	// only used for a nil configured env map
-	envAllocSize = 1 << 6
-)
+// shimEnv is the name of the environment variable storing decimal representation of
+// setup pipe fd for [container.Receive].
+const shimEnv = "HAKUREI_SHIM"
 
+// shimParams is embedded in outcomeState and transmitted from priv side to shim.
 type shimParams struct {
 	// Priv side pid, checked against ppid in signal handler for the syscall.SIGCONT hack.
 	PrivPID int
@@ -39,7 +36,7 @@ type shimParams struct {
 	// Limits are enforced on the priv side.
 	WaitDelay time.Duration
 
-	// Verbosity pass through from [container.Msg].
+	// Verbosity pass through from [message.Msg].
 	Verbose bool
 
 	// Outcome setup ops, contains setup state. Populated by outcome.finalise.
@@ -131,12 +128,12 @@ func ShimMain() {
 
 				// setup has not completed, terminate immediately
 				msg.Resume()
-				os.Exit(hst.ShimExitRequest)
+				os.Exit(hst.ExitRequest)
 				return
 
 			case 1: // got SIGCONT after adoption: monitor died before delivering signal
 				msg.BeforeExit()
-				os.Exit(hst.ShimExitOrphan)
+				os.Exit(hst.ExitOrphan)
 				return
 
 			case 2: // unreachable
@@ -172,7 +169,7 @@ func ShimMain() {
 
 	if err := z.Start(); err != nil {
 		printMessageError("cannot start container:", err)
-		os.Exit(1)
+		os.Exit(hst.ExitFailure)
 	}
 	if err := z.Serve(); err != nil {
 		printMessageError("cannot configure container:", err)
@@ -189,7 +186,7 @@ func ShimMain() {
 		var exitError *exec.ExitError
 		if !errors.As(err, &exitError) {
 			if errors.Is(err, context.Canceled) {
-				os.Exit(2)
+				os.Exit(hst.ExitCancel)
 			}
 			log.Printf("wait: %v", err)
 			os.Exit(127)

internal/app/spaccount_test.go

@@ -1,7 +1,6 @@
 package app
 
 import (
-	"maps"
 	"os"
 	"syscall"
 	"testing"
@@ -42,48 +41,32 @@ func TestSpAccountOp(t *testing.T) {
 			return c
 		}, nil, []stub.Call{
 			// this op performs basic validation and does not make calls during toSystem
-		}, newI(), nil, nil, func(state *outcomeStateParams) {
-			state.params.Ops = new(container.Ops)
-		}, []stub.Call{
+		}, newI(), nil, nil, insertsOps(nil), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, &container.Params{
 			Dir: config.Container.Home,
 			Ops: new(container.Ops).
 				Place(m("/etc/passwd"), []byte("chronos:x:1000:100:Hakurei:/data/data/org.chromium.Chromium:/run/current-system/sw/bin/zsh\n")).
 				Place(m("/etc/group"), []byte("hakurei:x:100:\n")),
-		}, func(t *testing.T, state *outcomeStateParams) {
-			wantEnv := map[string]string{
-				"HOME":  config.Container.Home.String(),
-				"USER":  config.Container.Username,
-				"SHELL": config.Container.Shell.String(),
-			}
-			maps.Copy(wantEnv, config.Container.Env)
-			if !maps.Equal(state.env, wantEnv) {
-				t.Errorf("toContainer: env = %#v, want %#v", state.env, wantEnv)
-			}
-		}, nil},
+		}, paramsWantEnv(config, map[string]string{
+			"HOME":  config.Container.Home.String(),
+			"USER":  config.Container.Username,
+			"SHELL": config.Container.Shell.String(),
+		}, nil), nil},
 
 		{"success", func(bool, bool) outcomeOp { return spAccountOp{} }, hst.Template, nil, []stub.Call{
 			// this op performs basic validation and does not make calls during toSystem
-		}, newI(), nil, nil, func(state *outcomeStateParams) {
-			state.params.Ops = new(container.Ops)
-		}, []stub.Call{
+		}, newI(), nil, nil, insertsOps(nil), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, &container.Params{
 			Dir: config.Container.Home,
 			Ops: new(container.Ops).
 				Place(m("/etc/passwd"), []byte("chronos:x:1000:100:Hakurei:/data/data/org.chromium.Chromium:/run/current-system/sw/bin/zsh\n")).
 				Place(m("/etc/group"), []byte("hakurei:x:100:\n")),
-		}, func(t *testing.T, state *outcomeStateParams) {
-			wantEnv := map[string]string{
-				"HOME":  config.Container.Home.String(),
-				"USER":  config.Container.Username,
-				"SHELL": config.Container.Shell.String(),
-			}
-			maps.Copy(wantEnv, config.Container.Env)
-			if !maps.Equal(state.env, wantEnv) {
-				t.Errorf("toContainer: env = %#v, want %#v", state.env, wantEnv)
-			}
-		}, nil},
+		}, paramsWantEnv(config, map[string]string{
+			"HOME":  config.Container.Home.String(),
+			"USER":  config.Container.Username,
+			"SHELL": config.Container.Shell.String(),
+		}, nil), nil},
 	})
 }

internal/app/spcontainer_test.go

@@ -2,7 +2,6 @@ package app
 
 import (
 	"errors"
-	"maps"
 	"os"
 	"reflect"
 	"syscall"
@@ -72,16 +71,9 @@ func TestSpParamsOp(t *testing.T) {
 				Proc(fhs.AbsProc).Tmpfs(hst.AbsPrivateTmp, 1<<12, 0755).
 				DevWritable(fhs.AbsDev, true).
 				Tmpfs(fhs.AbsDev.Append("shm"), 0, 01777),
+		}, paramsWantEnv(config, map[string]string{
+			"TERM": "xterm",
 		}, func(t *testing.T, state *outcomeStateParams) {
-			wantEnv := map[string]string{
-				"TERM": "xterm",
-			}
-			maps.Copy(wantEnv, config.Container.Env)
-			if !maps.Equal(state.env, wantEnv) {
-				t.Errorf("toContainer: env = %#v, want %#v", state.env, wantEnv)
-			}
-
-			const wantAutoEtcPrefix = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
 			if state.as.AutoEtcPrefix != wantAutoEtcPrefix {
 				t.Errorf("toContainer: as.AutoEtcPrefix = %q, want %q", state.as.AutoEtcPrefix, wantAutoEtcPrefix)
 			}
@@ -90,7 +82,7 @@ func TestSpParamsOp(t *testing.T) {
 			if !reflect.DeepEqual(state.filesystem, wantFilesystems) {
 				t.Errorf("toContainer: filesystem = %#v, want %#v", state.filesystem, wantFilesystems)
 			}
-		}, nil},
+		}), nil},
 
 		{"success", func(isShim, _ bool) outcomeOp {
 			if !isShim {
@@ -117,15 +109,9 @@ func TestSpParamsOp(t *testing.T) {
 				Proc(fhs.AbsProc).Tmpfs(hst.AbsPrivateTmp, 1<<12, 0755).
 				Bind(fhs.AbsDev, fhs.AbsDev, bits.BindWritable|bits.BindDevice).
 				Tmpfs(fhs.AbsDev.Append("shm"), 0, 01777),
+		}, paramsWantEnv(config, map[string]string{
+			"TERM": "xterm",
 		}, func(t *testing.T, state *outcomeStateParams) {
-			wantEnv := map[string]string{
-				"TERM": "xterm",
-			}
-			maps.Copy(wantEnv, config.Container.Env)
-			if !maps.Equal(state.env, wantEnv) {
-				t.Errorf("toContainer: env = %#v, want %#v", state.env, wantEnv)
-			}
-
 			if state.as.AutoEtcPrefix != wantAutoEtcPrefix {
 				t.Errorf("toContainer: as.AutoEtcPrefix = %q, want %q", state.as.AutoEtcPrefix, wantAutoEtcPrefix)
 			}
@@ -134,7 +120,7 @@ func TestSpParamsOp(t *testing.T) {
 			if !reflect.DeepEqual(state.filesystem, wantFilesystems) {
 				t.Errorf("toContainer: filesystem = %#v, want %#v", state.filesystem, wantFilesystems)
 			}
-		}, nil},
+		}), nil},
 	})
 }
 
@@ -159,6 +145,16 @@ func TestSpFilesystemOp(t *testing.T) {
 	}
 	configSmall := newConfigSmall()
 
+	needsApplyState := func(next pStateContainerFunc) pStateContainerFunc {
+		return func(state *outcomeStateParams) {
+			state.as = hst.ApplyState{AutoEtcPrefix: wantAutoEtcPrefix, Ops: opsAdapter{state.params.Ops}}
+
+			if next != nil {
+				next(state)
+			}
+		}
+	}
+
 	checkOpBehaviour(t, []opBehaviourTestCase{
 		{"readdir", func(bool, bool) outcomeOp {
 			return new(spFilesystemOp)
@@ -310,12 +306,9 @@ func TestSpFilesystemOp(t *testing.T) {
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.nixos/.ro-store"}, nePrefix+"/var/lib/hakurei/base/org.nixos/.ro-store", nil),
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.nixos/org.chromium.Chromium"}, nePrefix+"/var/lib/hakurei/base/org.nixos/org.chromium.Chromium", nil),
 			call("verbosef", stub.ExpectArgs{"hiding path %q from %q", []any{"/proc/nonexistent/eval/etc/dbus", "/etc/"}}, nil, nil),
-		}, newI(), nil, nil, func(state *outcomeStateParams) {
-			state.filesystem = configSmall.Container.Filesystem
-			state.params.Ops = new(container.Ops)
-			state.as = hst.ApplyState{AutoEtcPrefix: wantAutoEtcPrefix, Ops: opsAdapter{state.params.Ops}}
-			state.filesystem = append(state.filesystem, hst.FilesystemConfigJSON{})
-		}, []stub.Call{
+		}, newI(), nil, nil, insertsOps(needsApplyState(func(state *outcomeStateParams) {
+			state.filesystem = append(configSmall.Container.Filesystem, hst.FilesystemConfigJSON{})
+		})), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, nil, nil, &hst.AppError{
 			Step: "finalise",
@@ -341,11 +334,9 @@ func TestSpFilesystemOp(t *testing.T) {
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.nixos/.ro-store"}, nePrefix+"/var/lib/hakurei/base/org.nixos/.ro-store", nil),
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.nixos/org.chromium.Chromium"}, nePrefix+"/var/lib/hakurei/base/org.nixos/org.chromium.Chromium", nil),
 			call("verbosef", stub.ExpectArgs{"hiding path %q from %q", []any{"/proc/nonexistent/eval/etc/dbus", "/etc/"}}, nil, nil),
-		}, newI(), nil, nil, func(state *outcomeStateParams) {
+		}, newI(), nil, nil, insertsOps(needsApplyState(func(state *outcomeStateParams) {
 			state.filesystem = configSmall.Container.Filesystem
-			state.params.Ops = new(container.Ops)
-			state.as = hst.ApplyState{AutoEtcPrefix: wantAutoEtcPrefix, Ops: opsAdapter{state.params.Ops}}
-		}, []stub.Call{
+		})), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, &container.Params{
 			Ops: new(container.Ops).
@@ -386,11 +377,9 @@ func TestSpFilesystemOp(t *testing.T) {
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.debian/sys"}, nePrefix+"/var/lib/hakurei/base/org.debian/sys", nil),
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.debian/usr"}, nePrefix+"/var/lib/hakurei/base/org.debian/usr", nil),
 			call("evalSymlinks", stub.ExpectArgs{"/var/lib/hakurei/base/org.debian/var"}, nePrefix+"/var/lib/hakurei/base/org.debian/var", nil),
-		}, newI(), nil, nil, func(state *outcomeStateParams) {
+		}, newI(), nil, nil, insertsOps(needsApplyState(func(state *outcomeStateParams) {
 			state.filesystem = config.Container.Filesystem[1:]
-			state.params.Ops = new(container.Ops)
-			state.as = hst.ApplyState{AutoEtcPrefix: wantAutoEtcPrefix, Ops: opsAdapter{state.params.Ops}}
-		}, []stub.Call{
+		})), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, &container.Params{
 			Ops: new(container.Ops).

internal/app/spdbus.go

@@ -12,6 +12,7 @@ import (
 func init() { gob.Register(new(spDBusOp)) }
 
 // spDBusOp maintains an xdg-dbus-proxy instance for the container.
+// Runs after spRuntimeOp.
 type spDBusOp struct {
 	// Whether to bind the system bus socket. Populated during toSystem.
 	ProxySystem bool

internal/app/spdbus_test.go

@@ -1,8 +1,6 @@
 package app
 
 import (
-	"maps"
-	"reflect"
 	"syscall"
 	"testing"
 
@@ -18,7 +16,6 @@ import (
 
 func TestSpDBusOp(t *testing.T) {
 	config := hst.Template()
-	const instancePrefix = container.Nonexistent + "/tmp/hakurei.0/" + wantAutoEtcPrefix
 
 	checkOpBehaviour(t, []opBehaviourTestCase{
 		{"not enabled", func(bool, bool) outcomeOp {
@@ -41,11 +38,7 @@ func TestSpDBusOp(t *testing.T) {
 				"unix:path=/run/user/1000/bus",
 				"unix:path=/var/run/dbus/system_bus_socket",
 			}, nil),
-		}, nil, func(t *testing.T, state *outcomeStateSys) {
-			if want := m(instancePrefix); !reflect.DeepEqual(state.sharePath, want) {
-				t.Errorf("outcomeStateSys: sharePath = %v, want %v", state.sharePath, want)
-			}
-		}, &system.OpError{
+		}, nil, sysUsesInstance(nil), &system.OpError{
 			Op:     "dbus",
 			Err:    syscall.EINVAL,
 			Msg:    "message bus proxy configuration contains NUL byte",
@@ -66,7 +59,7 @@ func TestSpDBusOp(t *testing.T) {
 			call("isVerbose", stub.ExpectArgs{}, true, nil),
 			call("verbose", stub.ExpectArgs{[]any{"session bus proxy:", []string{
 				"unix:path=/run/user/1000/bus",
-				instancePrefix + "/bus",
+				wantInstancePrefix + "/bus",
 				"--filter",
 				"--talk=org.freedesktop.DBus",
 				"--talk=org.freedesktop.Notifications",
@@ -77,7 +70,7 @@ func TestSpDBusOp(t *testing.T) {
 			}}}, nil, nil),
 			call("verbose", stub.ExpectArgs{[]any{"message bus proxy final args:", helper.MustNewCheckedArgs(
 				"unix:path=/run/user/1000/bus",
-				instancePrefix+"/bus",
+				wantInstancePrefix+"/bus",
 				"--filter",
 				"--talk=org.freedesktop.DBus",
 				"--talk=org.freedesktop.Notifications",
@@ -88,40 +81,25 @@ func TestSpDBusOp(t *testing.T) {
 			)}}, nil, nil),
 		}, func() *system.I {
 			sys := system.New(panicMsgContext{}, message.NewMsg(nil), checkExpectUid)
-			sys.Ephemeral(system.Process, m(instancePrefix), 0711)
+			sys.Ephemeral(system.Process, m(wantInstancePrefix), 0711)
 			if err := sys.ProxyDBus(
 				dbus.NewConfig(config.ID, true, true), nil,
-				dbus.ProxyPair{"unix:path=/run/user/1000/bus", instancePrefix + "/bus"},
-				dbus.ProxyPair{"unix:path=/var/run/dbus/system_bus_socket", instancePrefix + "/system_bus_socket"},
+				dbus.ProxyPair{"unix:path=/run/user/1000/bus", wantInstancePrefix + "/bus"},
+				dbus.ProxyPair{"unix:path=/var/run/dbus/system_bus_socket", wantInstancePrefix + "/system_bus_socket"},
 			); err != nil {
 				t.Fatalf("cannot prepare sys: %v", err)
 			}
-			sys.UpdatePerm(m(instancePrefix+"/bus"), acl.Read, acl.Write)
+			sys.UpdatePerm(m(wantInstancePrefix+"/bus"), acl.Read, acl.Write)
 			return sys
-		}(), func(t *testing.T, state *outcomeStateSys) {
-			if want := m(instancePrefix); !reflect.DeepEqual(state.sharePath, want) {
-				t.Errorf("outcomeStateSys: sharePath = %v, want %v", state.sharePath, want)
-			}
-		}, nil, func(state *outcomeStateParams) {
-			state.params.Ops = new(container.Ops)
-
-			// emulates spRuntimeOp
-			state.runtimeDir = m("/run/user/1000")
-		}, []stub.Call{
+		}(), sysUsesInstance(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, &container.Params{
 			Ops: new(container.Ops).
-				Bind(m(instancePrefix+"/bus"),
+				Bind(m(wantInstancePrefix+"/bus"),
 					m("/run/user/1000/bus"), 0),
-		}, func(t *testing.T, state *outcomeStateParams) {
-			wantEnv := map[string]string{
-				"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1000/bus",
-			}
-			maps.Copy(wantEnv, config.Container.Env)
-			if !maps.Equal(state.env, wantEnv) {
-				t.Errorf("toContainer: env = %#v, want %#v", state.env, wantEnv)
-			}
-		}, nil},
+		}, paramsWantEnv(config, map[string]string{
+			"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1000/bus",
+		}, nil), nil},
 
 		{"success", func(isShim, _ bool) outcomeOp {
 			if !isShim {
@@ -136,7 +114,7 @@ func TestSpDBusOp(t *testing.T) {
 			call("isVerbose", stub.ExpectArgs{}, true, nil),
 			call("verbose", stub.ExpectArgs{[]any{"session bus proxy:", []string{
 				"unix:path=/run/user/1000/bus",
-				instancePrefix + "/bus",
+				wantInstancePrefix + "/bus",
 				"--filter",
 				"--talk=org.freedesktop.Notifications",
 				"--talk=org.freedesktop.FileManager1",
@@ -153,7 +131,7 @@ func TestSpDBusOp(t *testing.T) {
 			}}}, nil, nil),
 			call("verbose", stub.ExpectArgs{[]any{"system bus proxy:", []string{
 				"unix:path=/var/run/dbus/system_bus_socket",
-				instancePrefix + "/system_bus_socket",
+				wantInstancePrefix + "/system_bus_socket",
 				"--filter",
 				"--talk=org.bluez",
 				"--talk=org.freedesktop.Avahi",
@@ -161,7 +139,7 @@ func TestSpDBusOp(t *testing.T) {
 			}}}, nil, nil),
 			call("verbose", stub.ExpectArgs{[]any{"message bus proxy final args:", helper.MustNewCheckedArgs(
 				"unix:path=/run/user/1000/bus",
-				instancePrefix+"/bus",
+				wantInstancePrefix+"/bus",
 				"--filter",
 				"--talk=org.freedesktop.Notifications",
 				"--talk=org.freedesktop.FileManager1",
@@ -177,7 +155,7 @@ func TestSpDBusOp(t *testing.T) {
 				"--broadcast=org.freedesktop.portal.*=@/org/freedesktop/portal/*",
 
 				"unix:path=/var/run/dbus/system_bus_socket",
-				instancePrefix+"/system_bus_socket",
+				wantInstancePrefix+"/system_bus_socket",
 				"--filter",
 				"--talk=org.bluez",
 				"--talk=org.freedesktop.Avahi",
@@ -185,43 +163,28 @@ func TestSpDBusOp(t *testing.T) {
 			)}}, nil, nil),
 		}, func() *system.I {
 			sys := system.New(panicMsgContext{}, message.NewMsg(nil), checkExpectUid)
-			sys.Ephemeral(system.Process, m(instancePrefix), 0711)
+			sys.Ephemeral(system.Process, m(wantInstancePrefix), 0711)
 			if err := sys.ProxyDBus(
 				config.SessionBus, config.SystemBus,
-				dbus.ProxyPair{"unix:path=/run/user/1000/bus", instancePrefix + "/bus"},
-				dbus.ProxyPair{"unix:path=/var/run/dbus/system_bus_socket", instancePrefix + "/system_bus_socket"},
+				dbus.ProxyPair{"unix:path=/run/user/1000/bus", wantInstancePrefix + "/bus"},
+				dbus.ProxyPair{"unix:path=/var/run/dbus/system_bus_socket", wantInstancePrefix + "/system_bus_socket"},
 			); err != nil {
 				t.Fatalf("cannot prepare sys: %v", err)
 			}
-			sys.UpdatePerm(m(instancePrefix+"/bus"), acl.Read, acl.Write).
-				UpdatePerm(m(instancePrefix+"/system_bus_socket"), acl.Read, acl.Write)
+			sys.UpdatePerm(m(wantInstancePrefix+"/bus"), acl.Read, acl.Write).
+				UpdatePerm(m(wantInstancePrefix+"/system_bus_socket"), acl.Read, acl.Write)
 			return sys
-		}(), func(t *testing.T, state *outcomeStateSys) {
-			if want := m(instancePrefix); !reflect.DeepEqual(state.sharePath, want) {
-				t.Errorf("outcomeStateSys: sharePath = %v, want %v", state.sharePath, want)
-			}
-		}, nil, func(state *outcomeStateParams) {
-			state.params.Ops = new(container.Ops)
-
-			// emulates spRuntimeOp
-			state.runtimeDir = m("/run/user/1000")
-		}, []stub.Call{
+		}(), sysUsesInstance(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
 			// this op configures the container state and does not make calls during toContainer
 		}, &container.Params{
 			Ops: new(container.Ops).
-				Bind(m(instancePrefix+"/bus"),
+				Bind(m(wantInstancePrefix+"/bus"),
 					m("/run/user/1000/bus"), 0).
-				Bind(m(instancePrefix+"/system_bus_socket"),
+				Bind(m(wantInstancePrefix+"/system_bus_socket"),
 					m("/var/run/dbus/system_bus_socket"), 0),
-		}, func(t *testing.T, state *outcomeStateParams) {
-			wantEnv := map[string]string{
-				"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1000/bus",
-				"DBUS_SYSTEM_BUS_ADDRESS":  "unix:path=/var/run/dbus/system_bus_socket",
-			}
-			maps.Copy(wantEnv, config.Container.Env)
-			if !maps.Equal(state.env, wantEnv) {
-				t.Errorf("toContainer: env = %#v, want %#v", state.env, wantEnv)
-			}
-		}, nil},
+		}, paramsWantEnv(config, map[string]string{
+			"DBUS_SESSION_BUS_ADDRESS": "unix:path=/run/user/1000/bus",
+			"DBUS_SYSTEM_BUS_ADDRESS":  "unix:path=/var/run/dbus/system_bus_socket",
+		}, nil), nil},
 	})
 }

internal/app/spfinal_test.go

@@ -0,0 +1,65 @@
+package app
+
+import (
+	"syscall"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/fhs"
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+	"hakurei.app/system"
+	"hakurei.app/system/acl"
+)
+
+func TestSpFinalOp(t *testing.T) {
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"nil extra invalid env", func(bool, bool) outcomeOp {
+			return spFinalOp{}
+		}, func() *hst.Config {
+			c := hst.Template()
+			// verify nil check behaviour
+			c.ExtraPerms = append(c.ExtraPerms, hst.ExtraPermConfig{})
+			// verify toContainer behaviour
+			c.Container.Env["="] = "\x00"
+			return c
+		}, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/var/lib/hakurei/u0"), 0700).
+			UpdatePermType(system.User, m("/var/lib/hakurei/u0"),
+				acl.Execute).
+			UpdatePermType(system.User, m("/var/lib/hakurei/u0/org.chromium.Chromium"),
+				acl.Read, acl.Write, acl.Execute), nil, nil, func(state *outcomeStateParams) {
+			state.params.Ops = new(container.Ops)
+		}, []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, nil, nil, &hst.AppError{
+			Step: "flatten environment",
+			Err:  syscall.EINVAL,
+			Msg:  "invalid environment variable =",
+		}},
+
+		{"success", func(bool, bool) outcomeOp {
+			return spFinalOp{}
+		}, hst.Template, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/var/lib/hakurei/u0"), 0700).
+			UpdatePermType(system.User, m("/var/lib/hakurei/u0"),
+				acl.Execute).
+			UpdatePermType(system.User, m("/var/lib/hakurei/u0/org.chromium.Chromium"),
+				acl.Read, acl.Write, acl.Execute), nil, nil, func(state *outcomeStateParams) {
+			state.params.Ops = new(container.Ops)
+		}, []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Env: []string{
+				"GOOGLE_API_KEY=AIzaSyBHDrl33hwRp4rMQY0ziRbj8K9LPA6vUCY",
+				"GOOGLE_DEFAULT_CLIENT_ID=77185425430.apps.googleusercontent.com",
+				"GOOGLE_DEFAULT_CLIENT_SECRET=OTJgUOQcT7lO7GsGZq2G4IlT",
+			},
+			Ops: new(container.Ops).Remount(fhs.AbsRoot, syscall.MS_RDONLY),
+		}, nil, nil},
+	})
+}

internal/app/sppulse.go

@@ -7,10 +7,12 @@ import (
 	"io"
 	"io/fs"
 	"os"
+	"strconv"
 	"syscall"
 
 	"hakurei.app/container/check"
 	"hakurei.app/hst"
+	"hakurei.app/message"
 )
 
 const pulseCookieSizeMax = 1 << 8
@@ -18,9 +20,12 @@ const pulseCookieSizeMax = 1 << 8
 func init() { gob.Register(new(spPulseOp)) }
 
 // spPulseOp exports the PulseAudio server to the container.
+// Runs after spRuntimeOp.
 type spPulseOp struct {
 	// PulseAudio cookie data, populated during toSystem if a cookie is present.
 	Cookie *[pulseCookieSizeMax]byte
+	// PulseAudio cookie size, populated during toSystem if a cookie is present.
+	CookieSize int
 }
 
 func (s *spPulseOp) toSystem(state *outcomeStateSys) error {
@@ -34,115 +39,31 @@ func (s *spPulseOp) toSystem(state *outcomeStateSys) error {
 		if !errors.Is(err, fs.ErrNotExist) {
 			return &hst.AppError{Step: fmt.Sprintf("access PulseAudio directory %q", pulseRuntimeDir), Err: err}
 		}
-		return newWithMessage(fmt.Sprintf("PulseAudio directory %q not found", pulseRuntimeDir))
+		return newWithMessageError(fmt.Sprintf("PulseAudio directory %q not found", pulseRuntimeDir), err)
 	}
 
 	if fi, err := state.k.stat(pulseSocket.String()); err != nil {
 		if !errors.Is(err, fs.ErrNotExist) {
 			return &hst.AppError{Step: fmt.Sprintf("access PulseAudio socket %q", pulseSocket), Err: err}
 		}
-		return newWithMessage(fmt.Sprintf("PulseAudio directory %q found but socket does not exist", pulseRuntimeDir))
+		return newWithMessageError(fmt.Sprintf("PulseAudio directory %q found but socket does not exist", pulseRuntimeDir), err)
 	} else {
 		if m := fi.Mode(); m&0o006 != 0o006 {
 			return newWithMessage(fmt.Sprintf("unexpected permissions on %q: %s", pulseSocket, m))
 		}
 	}
 
-	// hard link pulse socket into target-executable share
+	// pulse socket is world writable and its parent directory DAC permissions prevents access;
+	// hard link to target-executable share directory to grant access
 	state.sys.Link(pulseSocket, state.runtime().Append("pulse"))
 
-	// publish current user's pulse cookie for target user
-	var paCookiePath *check.Absolute
-	{
-		const paLocateStep = "locate PulseAudio cookie"
-
-		// from environment
-		if p, ok := state.k.lookupEnv("PULSE_COOKIE"); ok {
-			if a, err := check.NewAbs(p); err != nil {
-				return &hst.AppError{Step: paLocateStep, Err: err}
-			} else {
-				// this takes precedence, do not verify whether the file is accessible
-				paCookiePath = a
-				goto out
-			}
-		}
-
-		// $HOME/.pulse-cookie
-		if p, ok := state.k.lookupEnv("HOME"); ok {
-			if a, err := check.NewAbs(p); err != nil {
-				return &hst.AppError{Step: paLocateStep, Err: err}
-			} else {
-				paCookiePath = a.Append(".pulse-cookie")
-			}
-
-			if fi, err := state.k.stat(paCookiePath.String()); err != nil {
-				paCookiePath = nil
-				if !errors.Is(err, fs.ErrNotExist) {
-					return &hst.AppError{Step: "access PulseAudio cookie", Err: err}
-				}
-				// fallthrough
-			} else if fi.IsDir() {
-				paCookiePath = nil
-			} else {
-				goto out
-			}
-		}
-
-		// $XDG_CONFIG_HOME/pulse/cookie
-		if p, ok := state.k.lookupEnv("XDG_CONFIG_HOME"); ok {
-			if a, err := check.NewAbs(p); err != nil {
-				return &hst.AppError{Step: paLocateStep, Err: err}
-			} else {
-				paCookiePath = a.Append("pulse", "cookie")
-			}
-			if fi, err := state.k.stat(paCookiePath.String()); err != nil {
-				paCookiePath = nil
-				if !errors.Is(err, fs.ErrNotExist) {
-					return &hst.AppError{Step: "access PulseAudio cookie", Err: err}
-				}
-				// fallthrough
-			} else if fi.IsDir() {
-				paCookiePath = nil
-			} else {
-				goto out
-			}
-		}
-	out:
-	}
-
-	if paCookiePath != nil {
-		if b, err := state.k.stat(paCookiePath.String()); err != nil {
-			return &hst.AppError{Step: "access PulseAudio cookie", Err: err}
-		} else {
-			if b.IsDir() {
-				return &hst.AppError{Step: "read PulseAudio cookie", Err: &os.PathError{Op: "stat", Path: paCookiePath.String(), Err: syscall.EISDIR}}
-			}
-			if b.Size() > pulseCookieSizeMax {
-				return newWithMessageError(
-					fmt.Sprintf("PulseAudio cookie at %q exceeds maximum expected size", paCookiePath),
-					&os.PathError{Op: "stat", Path: paCookiePath.String(), Err: syscall.ENOMEM},
-				)
-			}
-		}
-
-		var r io.ReadCloser
-		if f, err := state.k.open(paCookiePath.String()); err != nil {
-			return &hst.AppError{Step: "open PulseAudio cookie", Err: err}
-		} else {
-			r = f
-		}
-
+	// load up to pulseCookieSizeMax bytes of pulse cookie for transmission to shim
+	if a, err := discoverPulseCookie(state.k); err != nil {
+		return err
+	} else if a != nil {
 		s.Cookie = new([pulseCookieSizeMax]byte)
-		if n, err := r.Read(s.Cookie[:]); err != nil {
-			if !errors.Is(err, io.EOF) {
-				_ = r.Close()
-				return &hst.AppError{Step: "read PulseAudio cookie", Err: err}
-			}
-			state.msg.Verbosef("copied %d bytes from %q", n, paCookiePath)
-		}
-
-		if err := r.Close(); err != nil {
-			return &hst.AppError{Step: "close PulseAudio cookie", Err: err}
+		if s.CookieSize, err = loadFile(state.msg, state.k, "PulseAudio cookie", a.String(), s.Cookie[:]); err != nil {
+			return err
 		}
 	} else {
 		state.msg.Verbose("cannot locate PulseAudio cookie (tried " +
@@ -161,8 +82,12 @@ func (s *spPulseOp) toContainer(state *outcomeStateParams) error {
 
 	if s.Cookie != nil {
 		innerDst := hst.AbsPrivateTmp.Append("/pulse-cookie")
+
+		if s.CookieSize < 0 || s.CookieSize > pulseCookieSizeMax {
+			return newWithMessage("unexpected PulseAudio cookie size")
+		}
 		state.env["PULSE_COOKIE"] = innerDst.String()
-		state.params.Place(innerDst, s.Cookie[:])
+		state.params.Place(innerDst, s.Cookie[:s.CookieSize])
 	}
 
 	return nil
@@ -175,3 +100,111 @@ func (s *spPulseOp) commonPaths(state *outcomeState) (pulseRuntimeDir, pulseSock
 	pulseSocket = pulseRuntimeDir.Append("native")
 	return
 }
+
+// discoverPulseCookie attempts to discover the pathname of the PulseAudio cookie of the current user.
+// If both returned pathname and error are nil, the cookie is likely unavailable and can be silently skipped.
+func discoverPulseCookie(k syscallDispatcher) (*check.Absolute, error) {
+	const paLocateStep = "locate PulseAudio cookie"
+
+	// from environment
+	if p, ok := k.lookupEnv("PULSE_COOKIE"); ok {
+		if a, err := check.NewAbs(p); err != nil {
+			return nil, &hst.AppError{Step: paLocateStep, Err: err}
+		} else {
+			// this takes precedence, do not verify whether the file is accessible
+			return a, nil
+		}
+	}
+
+	// $HOME/.pulse-cookie
+	if p, ok := k.lookupEnv("HOME"); ok {
+		var pulseCookiePath *check.Absolute
+		if a, err := check.NewAbs(p); err != nil {
+			return nil, &hst.AppError{Step: paLocateStep, Err: err}
+		} else {
+			pulseCookiePath = a.Append(".pulse-cookie")
+		}
+
+		if fi, err := k.stat(pulseCookiePath.String()); err != nil {
+			if !errors.Is(err, fs.ErrNotExist) {
+				return nil, &hst.AppError{Step: "access PulseAudio cookie", Err: err}
+			}
+			// fallthrough
+		} else if fi.IsDir() {
+			// fallthrough
+		} else {
+			return pulseCookiePath, nil
+		}
+	}
+
+	// $XDG_CONFIG_HOME/pulse/cookie
+	if p, ok := k.lookupEnv("XDG_CONFIG_HOME"); ok {
+		var pulseCookiePath *check.Absolute
+		if a, err := check.NewAbs(p); err != nil {
+			return nil, &hst.AppError{Step: paLocateStep, Err: err}
+		} else {
+			pulseCookiePath = a.Append("pulse", "cookie")
+		}
+
+		if fi, err := k.stat(pulseCookiePath.String()); err != nil {
+			if !errors.Is(err, fs.ErrNotExist) {
+				return nil, &hst.AppError{Step: "access PulseAudio cookie", Err: err}
+			}
+			// fallthrough
+		} else if fi.IsDir() {
+			// fallthrough
+		} else {
+			return pulseCookiePath, nil
+		}
+	}
+
+	// cookie not present
+	// not fatal: authentication is disabled
+	return nil, nil
+}
+
+// loadFile reads up to len(buf) bytes from the file at pathname.
+func loadFile(
+	msg message.Msg, k syscallDispatcher,
+	description, pathname string, buf []byte,
+) (int, error) {
+	n := len(buf)
+	if n == 0 {
+		return -1, errors.New("invalid buffer")
+	}
+
+	if fi, err := k.stat(pathname); err != nil {
+		return -1, &hst.AppError{Step: "access " + description, Err: err}
+	} else {
+		if fi.IsDir() {
+			return -1, &hst.AppError{Step: "read " + description,
+				Err: &os.PathError{Op: "stat", Path: pathname, Err: syscall.EISDIR}}
+		}
+		if s := fi.Size(); s > int64(n) {
+			return -1, newWithMessageError(
+				description+" at "+strconv.Quote(pathname)+" exceeds expected size",
+				&os.PathError{Op: "stat", Path: pathname, Err: syscall.ENOMEM},
+			)
+		} else if s < int64(n) {
+			msg.Verbosef("%s at %q is %d bytes shorter than expected", description, pathname, int64(n)-s)
+		} else {
+			msg.Verbosef("loading %d bytes from %q", n, pathname)
+		}
+	}
+
+	if f, err := k.open(pathname); err != nil {
+		return -1, &hst.AppError{Step: "open " + description, Err: err}
+	} else {
+		if n, err = f.Read(buf); err != nil {
+			if !errors.Is(err, io.EOF) {
+				_ = f.Close()
+				return n, &hst.AppError{Step: "read " + description, Err: err}
+			}
+		}
+
+		if err = f.Close(); err != nil {
+			return n, &hst.AppError{Step: "close " + description, Err: err}
+		}
+		return n, nil
+	}
+}

internal/app/sppulse_test.go

@@ -0,0 +1,460 @@
+package app
+
+import (
+	"bytes"
+	"errors"
+	"os"
+	"syscall"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/check"
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+	"hakurei.app/system"
+	"hakurei.app/system/acl"
+)
+
+func TestSpPulseOp(t *testing.T) {
+	t.Parallel()
+
+	config := hst.Template()
+	sampleCookie := bytes.Repeat([]byte{0xfc}, pulseCookieSizeMax)
+
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"not enabled", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements = 0
+			return c
+		}, nil, nil, nil, nil, errNotEnabled, nil, nil, nil, nil, nil},
+
+		{"socketDir stat", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spPulseOp)
+			}
+			return &spPulseOp{Cookie: (*[256]byte)(sampleCookie)}
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), stub.UniqueError(2)),
+		}, nil, nil, &hst.AppError{
+			Step: `access PulseAudio directory "/proc/nonexistent/xdg_runtime_dir/pulse"`,
+			Err:  stub.UniqueError(2),
+		}, nil, nil, nil, nil, nil},
+
+		{"socketDir nonexistent", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), os.ErrNotExist),
+		}, nil, nil, &hst.AppError{
+			Step: "finalise",
+			Err:  os.ErrNotExist,
+			Msg:  `PulseAudio directory "/proc/nonexistent/xdg_runtime_dir/pulse" not found`,
+		}, nil, nil, nil, nil, nil},
+
+		{"socket stat", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, (*stubFi)(nil), stub.UniqueError(1)),
+		}, nil, nil, &hst.AppError{
+			Step: `access PulseAudio socket "/proc/nonexistent/xdg_runtime_dir/pulse/native"`,
+			Err:  stub.UniqueError(1),
+		}, nil, nil, nil, nil, nil},
+
+		{"socket nonexistent", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, (*stubFi)(nil), os.ErrNotExist),
+		}, nil, nil, &hst.AppError{
+			Step: "finalise",
+			Err:  os.ErrNotExist,
+			Msg:  `PulseAudio directory "/proc/nonexistent/xdg_runtime_dir/pulse" found but socket does not exist`,
+		}, nil, nil, nil, nil, nil},
+
+		{"socket mode", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0660}, nil),
+		}, nil, nil, &hst.AppError{
+			Step: "finalise",
+			Err:  os.ErrInvalid,
+			Msg:  `unexpected permissions on "/proc/nonexistent/xdg_runtime_dir/pulse/native": -rw-rw----`,
+		}, nil, nil, nil, nil, nil},
+
+		{"cookie notAbs", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "proc/nonexistent/cookie", nil),
+		}, nil, nil, &hst.AppError{
+			Step: "locate PulseAudio cookie",
+			Err:  &check.AbsoluteError{Pathname: "proc/nonexistent/cookie"},
+		}, nil, nil, nil, nil, nil},
+
+		{"cookie loadFile", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
+			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, (*stubOsFile)(nil), stub.UniqueError(0)),
+		}, nil, nil, &hst.AppError{
+			Step: "open PulseAudio cookie",
+			Err:  stub.UniqueError(0),
+		}, nil, nil, nil, nil, nil},
+
+		{"cookie bad shim size", func(isShim, clearUnexported bool) outcomeOp {
+			if !isShim {
+				return new(spPulseOp)
+			}
+			op := &spPulseOp{Cookie: (*[pulseCookieSizeMax]byte)(sampleCookie), CookieSize: pulseCookieSizeMax}
+			if clearUnexported {
+				op.CookieSize += +0xfd
+			}
+			return op
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
+			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// state.runtime
+			Ephemeral(system.Process, m(wantRuntimeSharePath), 0700).
+			UpdatePerm(m(wantRuntimeSharePath), acl.Execute).
+			// toSystem
+			Link(m(wantRuntimePath+"/pulse/native"), m(wantRuntimeSharePath+"/pulse")), sysUsesRuntime(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, nil, nil, &hst.AppError{
+			Step: "finalise",
+			Err:  os.ErrInvalid,
+			Msg:  "unexpected PulseAudio cookie size",
+		}},
+
+		{"success cookie short", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spPulseOp)
+			}
+			sampleCookieTrunc := make([]byte, pulseCookieSizeMax)
+			copy(sampleCookieTrunc, sampleCookie[:len(sampleCookie)-0xe])
+			return &spPulseOp{Cookie: (*[pulseCookieSizeMax]byte)(sampleCookieTrunc), CookieSize: pulseCookieSizeMax - 0xe}
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: pulseCookieSizeMax - 0xe}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"PulseAudio cookie", "/proc/nonexistent/cookie", int64(0xe)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie[:len(sampleCookie)-0xe])}, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// state.runtime
+			Ephemeral(system.Process, m(wantRuntimeSharePath), 0700).
+			UpdatePerm(m(wantRuntimeSharePath), acl.Execute).
+			// toSystem
+			Link(m(wantRuntimePath+"/pulse/native"), m(wantRuntimeSharePath+"/pulse")), sysUsesRuntime(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m(wantRuntimeSharePath+"/pulse"), m("/run/user/1000/pulse/native"), 0).
+				Place(m("/.hakurei/pulse-cookie"), sampleCookie[:len(sampleCookie)-0xe]),
+		}, paramsWantEnv(config, map[string]string{
+			"PULSE_SERVER": "unix:/run/user/1000/pulse/native",
+			"PULSE_COOKIE": "/.hakurei/pulse-cookie",
+		}, nil), nil},
+
+		{"success cookie", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spPulseOp)
+			}
+			return &spPulseOp{Cookie: (*[pulseCookieSizeMax]byte)(sampleCookie), CookieSize: pulseCookieSizeMax}
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
+			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// state.runtime
+			Ephemeral(system.Process, m(wantRuntimeSharePath), 0700).
+			UpdatePerm(m(wantRuntimeSharePath), acl.Execute).
+			// toSystem
+			Link(m(wantRuntimePath+"/pulse/native"), m(wantRuntimeSharePath+"/pulse")), sysUsesRuntime(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m(wantRuntimeSharePath+"/pulse"), m("/run/user/1000/pulse/native"), 0).
+				Place(m("/.hakurei/pulse-cookie"), sampleCookie),
+		}, paramsWantEnv(config, map[string]string{
+			"PULSE_SERVER": "unix:/run/user/1000/pulse/native",
+			"PULSE_COOKIE": "/.hakurei/pulse-cookie",
+		}, nil), nil},
+
+		{"success", func(bool, bool) outcomeOp {
+			return new(spPulseOp)
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, nil, nil),
+			call("verbose", stub.ExpectArgs{[]any{"cannot locate PulseAudio cookie (tried $PULSE_COOKIE, $XDG_CONFIG_HOME/pulse/cookie, $HOME/.pulse-cookie)"}}, nil, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// state.runtime
+			Ephemeral(system.Process, m(wantRuntimeSharePath), 0700).
+			UpdatePerm(m(wantRuntimeSharePath), acl.Execute).
+			// toSystem
+			Link(m(wantRuntimePath+"/pulse/native"), m(wantRuntimeSharePath+"/pulse")), sysUsesRuntime(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m(wantRuntimeSharePath+"/pulse"), m("/run/user/1000/pulse/native"), 0),
+		}, paramsWantEnv(config, map[string]string{
+			"PULSE_SERVER": "unix:/run/user/1000/pulse/native",
+		}, nil), nil},
+	})
+}
+
+func TestDiscoverPulseCookie(t *testing.T) {
+	t.Parallel()
+
+	fCheckPathname := func(k *kstub) error {
+		a, err := discoverPulseCookie(k)
+		k.Verbose(a)
+		return err
+	}
+
+	checkSimple(t, "discoverPulseCookie", []simpleTestCase{
+		{"override notAbs", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "proc/nonexistent/pulse-cookie", nil),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "locate PulseAudio cookie",
+			Err:  &check.AbsoluteError{Pathname: "proc/nonexistent/pulse-cookie"},
+		}},
+
+		{"success override", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/pulse-cookie", nil),
+			call("verbose", stub.ExpectArgs{[]any{m("/proc/nonexistent/pulse-cookie")}}, nil, nil),
+		}}, nil},
+
+		{"home notAbs", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, "proc/nonexistent/home", nil),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "locate PulseAudio cookie",
+			Err:  &check.AbsoluteError{Pathname: "proc/nonexistent/home"},
+		}},
+
+		{"home stat", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, "/proc/nonexistent/home", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/home/.pulse-cookie"}, (*stubFi)(nil), stub.UniqueError(1)),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "access PulseAudio cookie",
+			Err:  stub.UniqueError(1),
+		}},
+
+		{"home nonexistent", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, "/proc/nonexistent/home", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/home/.pulse-cookie"}, (*stubFi)(nil), os.ErrNotExist),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, nil, nil),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, nil},
+
+		{"success home", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, "/proc/nonexistent/home", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/home/.pulse-cookie"}, &stubFi{}, nil),
+			call("verbose", stub.ExpectArgs{[]any{m("/proc/nonexistent/home/.pulse-cookie")}}, nil, nil),
+		}}, nil},
+
+		{"xdg notAbs", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, "proc/nonexistent/xdg", nil),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "locate PulseAudio cookie",
+			Err:  &check.AbsoluteError{Pathname: "proc/nonexistent/xdg"},
+		}},
+
+		{"xdg stat", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, "/proc/nonexistent/xdg", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/xdg/pulse/cookie"}, (*stubFi)(nil), stub.UniqueError(0)),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "access PulseAudio cookie",
+			Err:  stub.UniqueError(0),
+		}},
+
+		{"xdg dir", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, "/proc/nonexistent/xdg", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/xdg/pulse/cookie"}, &stubFi{isDir: true}, nil),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, nil},
+
+		{"success home dir xdg nonexistent", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, "/proc/nonexistent/home", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/home/.pulse-cookie"}, &stubFi{isDir: true}, nil),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, "/proc/nonexistent/xdg", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/xdg/pulse/cookie"}, (*stubFi)(nil), os.ErrNotExist),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, nil},
+
+		{"success home nonexistent xdg", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, "/proc/nonexistent/home", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/home/.pulse-cookie"}, (*stubFi)(nil), os.ErrNotExist),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, "/proc/nonexistent/xdg", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/xdg/pulse/cookie"}, &stubFi{}, nil),
+			call("verbose", stub.ExpectArgs{[]any{m("/proc/nonexistent/xdg/pulse/cookie")}}, nil, nil),
+		}}, nil},
+
+		{"success empty environ", fCheckPathname, stub.Expect{Calls: []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"HOME"}, nil, nil),
+			call("lookupEnv", stub.ExpectArgs{"XDG_CONFIG_HOME"}, nil, nil),
+			call("verbose", stub.ExpectArgs{[]any{(*check.Absolute)(nil)}}, nil, nil),
+		}}, nil},
+	})
+}
+
+func TestLoadFile(t *testing.T) {
+	t.Parallel()
+
+	fAfterWriteExact := func(k *kstub) error {
+		buf := make([]byte, 1<<8)
+		n, err := loadFile(k, k,
+			"simulated PulseAudio cookie",
+			"/home/ophestra/xdg/config/pulse/cookie",
+			buf)
+		k.Verbose(buf[:n])
+		return err
+	}
+
+	fAfterWrite := func(k *kstub) error {
+		buf := make([]byte, 1<<8+0xfd)
+		n, err := loadFile(k, k,
+			"simulated PulseAudio cookie",
+			"/home/ophestra/xdg/config/pulse/cookie",
+			buf)
+		k.Verbose(buf[:n])
+		return err
+	}
+
+	fBeforeWrite := func(k *kstub) error {
+		buf := make([]byte, 1<<8+0xfd)
+		n, err := loadFile(k, k,
+			"simulated PulseAudio cookie",
+			"/home/ophestra/xdg/config/pulse/cookie",
+			buf)
+		k.Verbose(n)
+
+		if !bytes.Equal(buf, make([]byte, len(buf))) {
+			t.Errorf("loadFile: buf = %#v", buf)
+		}
+		return err
+	}
+
+	sampleCookie := bytes.Repeat([]byte{0xfc}, pulseCookieSizeMax)
+	checkSimple(t, "loadFile", []simpleTestCase{
+		{"buf", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				nil)
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, errors.New("invalid buffer")},
+
+		{"stat", fBeforeWrite, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, (*stubFi)(nil), stub.UniqueError(3)),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "access simulated PulseAudio cookie",
+			Err:  stub.UniqueError(3),
+		}},
+
+		{"dir", fBeforeWrite, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{isDir: true}, nil),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "read simulated PulseAudio cookie",
+			Err:  &os.PathError{Op: "stat", Path: "/home/ophestra/xdg/config/pulse/cookie", Err: syscall.EISDIR},
+		}},
+
+		{"oob", fBeforeWrite, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1<<8 + 0xff}, nil),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "finalise",
+			Err:  &os.PathError{Op: "stat", Path: "/home/ophestra/xdg/config/pulse/cookie", Err: syscall.ENOMEM},
+			Msg:  `simulated PulseAudio cookie at "/home/ophestra/xdg/config/pulse/cookie" exceeds expected size`,
+		}},
+
+		{"open", fBeforeWrite, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, (*stubOsFile)(nil), stub.UniqueError(2)),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{Step: "open simulated PulseAudio cookie", Err: stub.UniqueError(2)}},
+
+		{"read", fBeforeWrite, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{Reader: errorReader{stub.UniqueError(1)}}, nil),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{Step: "read simulated PulseAudio cookie", Err: stub.UniqueError(1)}},
+
+		{"short close", fAfterWrite, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{closeErr: stub.UniqueError(0), Reader: bytes.NewReader(sampleCookie)}, nil),
+			call("verbose", stub.ExpectArgs{[]any{sampleCookie}}, nil, nil),
+		}}, &hst.AppError{Step: "close simulated PulseAudio cookie", Err: stub.UniqueError(0)}},
+
+		{"success", fAfterWriteExact, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/home/ophestra/xdg/config/pulse/cookie"}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),
+			call("verbose", stub.ExpectArgs{[]any{sampleCookie}}, nil, nil),
+		}}, nil},
+	})
+}

internal/app/spruntime.go

@@ -6,43 +6,114 @@ import (
 	"hakurei.app/container/bits"
 	"hakurei.app/container/check"
 	"hakurei.app/container/fhs"
+	"hakurei.app/hst"
 	"hakurei.app/system"
 	"hakurei.app/system/acl"
 )
 
-func init() { gob.Register(spRuntimeOp{}) }
+const (
+	/*
+		Path to a user-private user-writable directory that is bound
+		to the user login time on the machine. It is automatically
+		created the first time a user logs in and removed on the
+		user's final logout. If a user logs in twice at the same time,
+		both sessions will see the same $XDG_RUNTIME_DIR and the same
+		contents. If a user logs in once, then logs out again, and
+		logs in again, the directory contents will have been lost in
+		between, but applications should not rely on this behavior and
+		must be able to deal with stale files. To store
+		session-private data in this directory, the user should
+		include the value of $XDG_SESSION_ID in the filename. This
+		directory shall be used for runtime file system objects such
+		as AF_UNIX sockets, FIFOs, PID files and similar. It is
+		guaranteed that this directory is local and offers the
+		greatest possible file system feature set the operating system
+		provides. For further details, see the XDG Base Directory
+		Specification[3].  $XDG_RUNTIME_DIR is not set if the current
+		user is not the original user of the session.
+	*/
+	envXDGRuntimeDir = "XDG_RUNTIME_DIR"
+
+	/*
+		The session class. This may be used instead of class= on the
+		module parameter line, and is usually preferred.
+	*/
+	envXDGSessionClass = "XDG_SESSION_CLASS"
+
+	/*
+		A regular interactive user session. This is the default class
+		for sessions for which a TTY or X display is known at session
+		registration time.
+	*/
+	xdgSessionClassUser = "user"
+
+	/*
+		The session type. This may be used instead of type= on the
+		module parameter line, and is usually preferred.
+
+		One of "unspecified", "tty", "x11", "wayland", "mir", or "web".
+	*/
+	envXDGSessionType = "XDG_SESSION_TYPE"
+)
+
+func init() { gob.Register(new(spRuntimeOp)) }
+
+const (
+	sessionTypeUnspec = iota
+	sessionTypeTTY
+	sessionTypeX11
+	sessionTypeWayland
+)
 
 // spRuntimeOp sets up XDG_RUNTIME_DIR inside the container.
-type spRuntimeOp struct{}
+type spRuntimeOp struct {
+	// SessionType determines the value of envXDGSessionType. Populated during toSystem.
+	SessionType uintptr
+}
 
-func (s spRuntimeOp) toSystem(state *outcomeStateSys) error {
+func (s *spRuntimeOp) toSystem(state *outcomeStateSys) error {
 	runtimeDir, runtimeDirInst := s.commonPaths(state.outcomeState)
 	state.sys.Ensure(runtimeDir, 0700)
 	state.sys.UpdatePermType(system.User, runtimeDir, acl.Execute)
 	state.sys.Ensure(runtimeDirInst, 0700)
 	state.sys.UpdatePermType(system.User, runtimeDirInst, acl.Read, acl.Write, acl.Execute)
+
+	if state.et&hst.EWayland != 0 {
+		s.SessionType = sessionTypeWayland
+	} else if state.et&hst.EX11 != 0 {
+		s.SessionType = sessionTypeX11
+	} else {
+		s.SessionType = sessionTypeTTY
+	}
+
 	return nil
 }
 
-func (s spRuntimeOp) toContainer(state *outcomeStateParams) error {
-	const (
-		xdgRuntimeDir   = "XDG_RUNTIME_DIR"
-		xdgSessionClass = "XDG_SESSION_CLASS"
-		xdgSessionType  = "XDG_SESSION_TYPE"
-	)
-
+func (s *spRuntimeOp) toContainer(state *outcomeStateParams) error {
 	state.runtimeDir = fhs.AbsRunUser.Append(state.mapuid.String())
-	state.env[xdgRuntimeDir] = state.runtimeDir.String()
-	state.env[xdgSessionClass] = "user"
-	state.env[xdgSessionType] = "tty"
+	state.env[envXDGRuntimeDir] = state.runtimeDir.String()
+	state.env[envXDGSessionClass] = xdgSessionClassUser
+
+	switch s.SessionType {
+	case sessionTypeUnspec:
+		state.env[envXDGSessionType] = "unspecified"
+	case sessionTypeTTY:
+		state.env[envXDGSessionType] = "tty"
+	case sessionTypeX11:
+		state.env[envXDGSessionType] = "x11"
+	case sessionTypeWayland:
+		state.env[envXDGSessionType] = "wayland"
+
+	}
 
 	_, runtimeDirInst := s.commonPaths(state.outcomeState)
-	state.params.Tmpfs(fhs.AbsRunUser, 1<<12, 0755)
-	state.params.Bind(runtimeDirInst, state.runtimeDir, bits.BindWritable)
+	state.params.
+		Tmpfs(fhs.AbsRunUser, 1<<12, 0755).
+		Bind(runtimeDirInst, state.runtimeDir, bits.BindWritable)
 	return nil
 }
 
-func (s spRuntimeOp) commonPaths(state *outcomeState) (runtimeDir, runtimeDirInst *check.Absolute) {
+func (s *spRuntimeOp) commonPaths(state *outcomeState) (runtimeDir, runtimeDirInst *check.Absolute) {
 	runtimeDir = state.sc.SharePath.Append("runtime")
 	runtimeDirInst = runtimeDir.Append(state.identity.String())
 	return

internal/app/spruntime_test.go

@@ -0,0 +1,128 @@
+package app
+
+import (
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/bits"
+	"hakurei.app/container/fhs"
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+	"hakurei.app/system"
+	"hakurei.app/system/acl"
+)
+
+func TestSpRuntimeOp(t *testing.T) {
+	t.Parallel()
+	config := hst.Template()
+
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"success zero", func(isShim bool, clearUnexported bool) outcomeOp {
+			if !isShim {
+				return new(spRuntimeOp)
+			}
+			op := &spRuntimeOp{sessionTypeTTY}
+			if clearUnexported {
+				op.SessionType = sessionTypeUnspec
+			}
+			return op
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements = 0
+			return c
+		}, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime"), acl.Execute).
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), acl.Read, acl.Write, acl.Execute), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Tmpfs(fhs.AbsRunUser, 1<<12, 0755).
+				Bind(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), m("/run/user/1000"), bits.BindWritable),
+		}, paramsWantEnv(config, map[string]string{
+			"XDG_RUNTIME_DIR":   "/run/user/1000",
+			"XDG_SESSION_CLASS": "user",
+			"XDG_SESSION_TYPE":  "unspecified",
+		}, nil), nil},
+
+		{"success tty", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spRuntimeOp)
+			}
+			return &spRuntimeOp{sessionTypeTTY}
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements = 0
+			return c
+		}, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime"), acl.Execute).
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), acl.Read, acl.Write, acl.Execute), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Tmpfs(fhs.AbsRunUser, 1<<12, 0755).
+				Bind(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), m("/run/user/1000"), bits.BindWritable),
+		}, paramsWantEnv(config, map[string]string{
+			"XDG_RUNTIME_DIR":   "/run/user/1000",
+			"XDG_SESSION_CLASS": "user",
+			"XDG_SESSION_TYPE":  "tty",
+		}, nil), nil},
+
+		{"success x11", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spRuntimeOp)
+			}
+			return &spRuntimeOp{sessionTypeX11}
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements = hst.Enablements(hst.EX11)
+			return c
+		}, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime"), acl.Execute).
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), acl.Read, acl.Write, acl.Execute), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Tmpfs(fhs.AbsRunUser, 1<<12, 0755).
+				Bind(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), m("/run/user/1000"), bits.BindWritable),
+		}, paramsWantEnv(config, map[string]string{
+			"XDG_RUNTIME_DIR":   "/run/user/1000",
+			"XDG_SESSION_CLASS": "user",
+			"XDG_SESSION_TYPE":  "x11",
+		}, nil), nil},
+
+		{"success", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spRuntimeOp)
+			}
+			return &spRuntimeOp{sessionTypeWayland}
+		}, hst.Template, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime"), acl.Execute).
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), acl.Read, acl.Write, acl.Execute), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Tmpfs(fhs.AbsRunUser, 1<<12, 0755).
+				Bind(m("/proc/nonexistent/tmp/hakurei.0/runtime/9"), m("/run/user/1000"), bits.BindWritable),
+		}, paramsWantEnv(config, map[string]string{
+			"XDG_RUNTIME_DIR":   "/run/user/1000",
+			"XDG_SESSION_CLASS": "user",
+			"XDG_SESSION_TYPE":  "wayland",
+		}, nil), nil},
+	})
+}

internal/app/sptmpdir_test.go

@@ -0,0 +1,34 @@
+package app
+
+import (
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/bits"
+	"hakurei.app/container/fhs"
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+	"hakurei.app/system"
+	"hakurei.app/system/acl"
+)
+
+func TestSpTmpdirOp(t *testing.T) {
+	t.Parallel()
+
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"success", func(bool, bool) outcomeOp {
+			return spTmpdirOp{}
+		}, hst.Template, nil, []stub.Call{
+			// this op configures the system state and does not make calls during toSystem
+		}, newI().
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/tmpdir"), 0700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/tmpdir"), acl.Execute).
+			Ensure(m("/proc/nonexistent/tmp/hakurei.0/tmpdir/9"), 01700).
+			UpdatePermType(system.User, m("/proc/nonexistent/tmp/hakurei.0/tmpdir/9"), acl.Read, acl.Write, acl.Execute), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m("/proc/nonexistent/tmp/hakurei.0/tmpdir/9"), fhs.AbsTmp, bits.BindWritable),
+		}, nil, nil},
+	})
+}

internal/app/spwayland.go

@@ -12,6 +12,7 @@ import (
 func init() { gob.Register(new(spWaylandOp)) }
 
 // spWaylandOp exports the Wayland display server to the container.
+// Runs after spRuntimeOp.
 type spWaylandOp struct {
 	// Path to host wayland socket. Populated during toSystem if DirectWayland is true.
 	SocketPath *check.Absolute

internal/app/spwayland_test.go

@@ -0,0 +1,104 @@
+package app
+
+import (
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+	"hakurei.app/system"
+	"hakurei.app/system/acl"
+	"hakurei.app/system/wayland"
+)
+
+func TestSpWaylandOp(t *testing.T) {
+	t.Parallel()
+	config := hst.Template()
+
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"not enabled", func(bool, bool) outcomeOp {
+			return new(spWaylandOp)
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements = 0
+			return c
+		}, nil, nil, nil, nil, errNotEnabled, nil, nil, nil, nil, nil},
+
+		{"success notAbs defaultAppId", func(bool, bool) outcomeOp {
+			return new(spWaylandOp)
+		}, func() *hst.Config {
+			c := hst.Template()
+			c.ID = ""
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"WAYLAND_DISPLAY"}, "wayland-1", nil),
+		}, newI().
+			// state.instance
+			Ephemeral(system.Process, m(wantInstancePrefix), 0711).
+			// toSystem
+			Wayland(
+				m(wantInstancePrefix+"/wayland"),
+				m(wantRuntimePath+"/wayland-1"),
+				"app.hakurei."+wantAutoEtcPrefix,
+				wantAutoEtcPrefix,
+			), sysUsesInstance(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m(wantInstancePrefix+"/wayland"), m("/run/user/1000/wayland-0"), 0),
+		}, paramsWantEnv(config, map[string]string{
+			wayland.WaylandDisplay: wayland.FallbackName,
+		}, nil), nil},
+
+		{"success direct", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spWaylandOp)
+			}
+			return &spWaylandOp{SocketPath: m("/proc/nonexistent/wayland")}
+		}, func() *hst.Config {
+			c := hst.Template()
+			c.DirectWayland = true
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"WAYLAND_DISPLAY"}, "/proc/nonexistent/wayland", nil),
+			call("verbose", stub.ExpectArgs{[]any{"direct wayland access, PROCEED WITH CAUTION"}}, nil, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// toSystem
+			UpdatePermType(hst.EWayland, m("/proc/nonexistent/wayland"), acl.Read, acl.Write, acl.Execute), nil, nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m("/proc/nonexistent/wayland"), m("/run/user/1000/wayland-0"), 0),
+		}, paramsWantEnv(config, map[string]string{
+			wayland.WaylandDisplay: wayland.FallbackName,
+		}, nil), nil},
+
+		{"success", func(bool, bool) outcomeOp {
+			return new(spWaylandOp)
+		}, hst.Template, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"WAYLAND_DISPLAY"}, nil, nil),
+			call("verbose", stub.ExpectArgs{[]any{"WAYLAND_DISPLAY is not set, assuming wayland-0"}}, nil, nil),
+		}, newI().
+			// state.instance
+			Ephemeral(system.Process, m(wantInstancePrefix), 0711).
+			// toSystem
+			Wayland(
+				m(wantInstancePrefix+"/wayland"),
+				m(wantRuntimePath+"/"+wayland.FallbackName),
+				"org.chromium.Chromium",
+				wantAutoEtcPrefix,
+			), sysUsesInstance(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m(wantInstancePrefix+"/wayland"), m("/run/user/1000/wayland-0"), 0),
+		}, paramsWantEnv(config, map[string]string{
+			wayland.WaylandDisplay: wayland.FallbackName,
+		}, nil), nil},
+	})
+}

internal/app/spx11_test.go

@@ -0,0 +1,119 @@
+package app
+
+import (
+	"os"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/container/stub"
+	"hakurei.app/hst"
+	"hakurei.app/system/acl"
+)
+
+func TestSpX11Op(t *testing.T) {
+	t.Parallel()
+	config := hst.Template()
+
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"not enabled", func(bool, bool) outcomeOp {
+			return new(spX11Op)
+		}, hst.Template, nil, nil, nil, nil, errNotEnabled, nil, nil, nil, nil, nil},
+
+		{"lookupEnv", func(bool, bool) outcomeOp {
+			return new(spX11Op)
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements |= hst.Enablements(hst.EX11)
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"DISPLAY"}, nil, nil),
+		}, nil, nil, &hst.AppError{
+			Step: "finalise",
+			Err:  os.ErrInvalid,
+			Msg:  "DISPLAY is not set",
+		}, nil, nil, nil, nil, nil},
+
+		{"abs stat", func(bool, bool) outcomeOp {
+			return new(spX11Op)
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements |= hst.Enablements(hst.EX11)
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"DISPLAY"}, "unix:/tmp/.X11-unix/X0", nil),
+			call("stat", stub.ExpectArgs{"/tmp/.X11-unix/X0"}, (*stubFi)(nil), stub.UniqueError(0)),
+		}, nil, nil, &hst.AppError{
+			Step: `access X11 socket "/tmp/.X11-unix/X0"`,
+			Err:  stub.UniqueError(0),
+		}, nil, nil, nil, nil, nil},
+
+		{"success abs nonexistent", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spX11Op)
+			}
+			return &spX11Op{Display: "unix:/tmp/.X11-unix/X0"}
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements |= hst.Enablements(hst.EX11)
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"DISPLAY"}, "unix:/tmp/.X11-unix/X0", nil),
+			call("stat", stub.ExpectArgs{"/tmp/.X11-unix/X0"}, (*stubFi)(nil), os.ErrNotExist),
+		}, newI().
+			ChangeHosts("#1000009"), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(absX11SocketDir, absX11SocketDir, 0),
+		}, paramsWantEnv(config, map[string]string{
+			"DISPLAY": "unix:/tmp/.X11-unix/X0",
+		}, nil), nil},
+
+		{"success abs abstract", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spX11Op)
+			}
+			return &spX11Op{Display: "unix:/tmp/.X11-unix/X0"}
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements |= hst.Enablements(hst.EX11)
+			c.Container.Flags &= ^hst.FHostAbstract
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"DISPLAY"}, "unix:/tmp/.X11-unix/X0", nil),
+			call("stat", stub.ExpectArgs{"/tmp/.X11-unix/X0"}, (*stubFi)(nil), nil),
+		}, newI().
+			UpdatePermType(hst.EX11, m("/tmp/.X11-unix/X0"), acl.Read, acl.Write, acl.Execute).
+			ChangeHosts("#1000009"), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(absX11SocketDir, absX11SocketDir, 0),
+		}, paramsWantEnv(config, map[string]string{
+			"DISPLAY": "unix:/tmp/.X11-unix/X0",
+		}, nil), nil},
+
+		{"success", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spX11Op)
+			}
+			return &spX11Op{Display: ":0"}
+		}, func() *hst.Config {
+			c := hst.Template()
+			*c.Enablements |= hst.Enablements(hst.EX11)
+			return c
+		}, nil, []stub.Call{
+			call("lookupEnv", stub.ExpectArgs{"DISPLAY"}, ":0", nil),
+			call("stat", stub.ExpectArgs{"/tmp/.X11-unix/X0"}, (*stubFi)(nil), nil),
+		}, newI().
+			UpdatePermType(hst.EX11, m("/tmp/.X11-unix/X0"), acl.Read, acl.Write, acl.Execute).
+			ChangeHosts("#1000009"), nil, nil, insertsOps(nil), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(absX11SocketDir, absX11SocketDir, 0),
+		}, paramsWantEnv(config, map[string]string{
+			"DISPLAY": ":0",
+		}, nil), nil},
+	})
+}

ldd/exec.go

@@ -16,17 +16,17 @@ import (
 	"hakurei.app/message"
 )
 
-const (
-	lddName    = "ldd"
-	lddTimeout = 2 * time.Second
-)
-
 var (
 	msgStatic      = []byte("Not a valid dynamic program")
 	msgStaticGlibc = []byte("not a dynamic executable")
 )
 
 func Exec(ctx context.Context, msg message.Msg, p string) ([]*Entry, error) {
+	const (
+		lddName    = "ldd"
+		lddTimeout = 4 * time.Second
+	)
+
 	c, cancel := context.WithTimeout(ctx, lddTimeout)
 	defer cancel()
 

test/sandbox/case/device.nix

@@ -46,7 +46,7 @@ in
       "WAYLAND_DISPLAY=wayland-0"
       "XDG_RUNTIME_DIR=/run/user/65534"
       "XDG_SESSION_CLASS=user"
-      "XDG_SESSION_TYPE=tty"
+      "XDG_SESSION_TYPE=wayland"
     ];
 
     fs = fs "dead" {
@@ -218,6 +218,15 @@ in
       (ent "/" ignore ignore ignore ignore ignore)
       (ent "/" ignore ignore ignore ignore ignore)
       (ent "/" "/dev/shm" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,uid=1000004,gid=1000004")
+      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000004,gid=1000004")
+      (ent "/tmp/hakurei.0/runtime/4" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/tmp/hakurei.0/tmpdir/4" "/tmp" "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 "/tmp/.X11-unix" "/tmp/.X11-unix" "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 "/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")
@@ -233,15 +242,6 @@ in
       (ent "/" "/.hakurei/store" "rw,relatime" "overlay" "overlay" "rw,lowerdir=/host/nix/.ro-store:/host/nix/.rw-store/upper,upperdir=/host/tmp/.hakurei-store-rw/upper,workdir=/host/tmp/.hakurei-store-rw/work,redirect_dir=nofollow,userxattr")
       (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/var/lib/hakurei/u0/a4" "/var/lib/hakurei/u0/a4" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000004,gid=1000004")
-      (ent "/tmp/hakurei.0/runtime/4" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/tmp/hakurei.0/tmpdir/4" "/tmp" "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 "/tmp/.X11-unix" "/tmp/.X11-unix" "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")
     ];
 
     seccomp = true;

test/sandbox/case/mapuid.nix

@@ -54,7 +54,7 @@ in
       "WAYLAND_DISPLAY=wayland-0"
       "XDG_RUNTIME_DIR=/run/user/1000"
       "XDG_SESSION_CLASS=user"
-      "XDG_SESSION_TYPE=tty"
+      "XDG_SESSION_TYPE=wayland"
     ];
 
     fs = fs "dead" {
@@ -245,6 +245,14 @@ in
       (ent "/" "/dev/pts" "rw,nosuid,noexec,relatime" "devpts" "devpts" "rw,mode=620,ptmxmode=666")
       (ent "/" "/dev/mqueue" "rw,nosuid,nodev,noexec,relatime" "mqueue" "mqueue" "rw")
       (ent "/" "/dev/shm" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,uid=1000003,gid=1000003")
+      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000003,gid=1000003")
+      (ent "/tmp/hakurei.0/runtime/3" "/run/user/1000" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/tmp/hakurei.0/tmpdir/3" "/tmp" "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")
+      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000003,gid=1000003")
+      (ent ignore "/run/user/1000/wayland-0" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent ignore "/run/user/1000/pulse/native" "ro,nosuid,nodev,relatime" "tmpfs" "tmpfs" ignore)
+      (ent ignore "/run/user/1000/bus" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (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")
@@ -260,14 +268,6 @@ in
       (ent "/" "/.hakurei/store" "rw,relatime" "overlay" "overlay" "rw,lowerdir=/host/nix/.ro-store:/host/nix/.rw-store/upper,upperdir=/host/tmp/.hakurei-store-rw/upper,workdir=/host/tmp/.hakurei-store-rw/work,redirect_dir=nofollow,userxattr")
       (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/var/lib/hakurei/u0/a3" "/var/lib/hakurei/u0/a3" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000003,gid=1000003")
-      (ent "/tmp/hakurei.0/runtime/3" "/run/user/1000" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/tmp/hakurei.0/tmpdir/3" "/tmp" "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")
-      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000003,gid=1000003")
-      (ent ignore "/run/user/1000/wayland-0" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent ignore "/run/user/1000/pulse/native" "ro,nosuid,nodev,relatime" "tmpfs" "tmpfs" ignore)
-      (ent ignore "/run/user/1000/bus" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
     ];
 
     seccomp = true;

test/sandbox/case/pd.nix

@@ -161,7 +161,7 @@
       (ent "/../../.." "/sys/fs/cgroup" "rw,nosuid,nodev,noexec,relatime" "cgroup2" "cgroup2" "rw,nsdelegate,memory_recursiveprot")
       (ent "/" "/sys/fs/pstore" "rw,nosuid,nodev,noexec,relatime" "pstore" "pstore" "rw")
       (ent "/" "/sys/fs/bpf" "rw,nosuid,nodev,noexec,relatime" "bpf" "bpf" "rw,mode=700")
-      # systemd race: tracefs debugfs configfs fusectl
+      # systemd nondeterminism: tracefs debugfs configfs fusectl
       (ent "/" ignore "rw,nosuid,nodev,noexec,relatime" ignore ignore "rw")
       (ent "/" ignore "rw,nosuid,nodev,noexec,relatime" ignore ignore "rw")
       (ent "/" ignore "rw,nosuid,nodev,noexec,relatime" ignore ignore "rw")
@@ -181,16 +181,16 @@
       (ent ignore "/dev/console" "rw,nosuid,noexec,relatime" "devpts" "devpts" "rw,gid=3,mode=620,ptmxmode=666")
       (ent "/" "/dev/mqueue" "rw,nosuid,nodev,noexec,relatime" "mqueue" "mqueue" "rw")
       (ent "/" "/dev/shm" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,uid=1000000,gid=1000000")
-      (ent "/kvm" "/dev/kvm" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
-      (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/" "/run/user/1000" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=8k,mode=755,uid=1000000,gid=1000000")
-      (ent "/" "/run/nscd" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=8k,mode=755,uid=1000000,gid=1000000")
-      (ent "/" "/run/dbus" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=8k,mode=755,uid=1000000,gid=1000000")
       (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000000,gid=1000000")
       (ent "/tmp/hakurei.0/runtime/0" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/tmp/hakurei.0/tmpdir/0" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000000,gid=1000000")
       (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000000,gid=1000000")
+      (ent "/kvm" "/dev/kvm" "rw,nosuid" "devtmpfs" "devtmpfs" ignore)
+      (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/" "/run/user/1000" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=8k,mode=755,uid=1000000,gid=1000000")
+      (ent "/" "/run/nscd" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=8k,mode=755,uid=1000000,gid=1000000")
+      (ent "/" "/run/dbus" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=8k,mode=755,uid=1000000,gid=1000000")
     ];
 
     seccomp = true;

test/sandbox/case/pdlike.nix

@@ -54,7 +54,7 @@ in
       "WAYLAND_DISPLAY=wayland-0"
       "XDG_RUNTIME_DIR=/run/user/65534"
       "XDG_SESSION_CLASS=user"
-      "XDG_SESSION_TYPE=tty"
+      "XDG_SESSION_TYPE=wayland"
     ];
 
     fs = fs "dead" {
@@ -243,6 +243,14 @@ in
       (ent ignore "/dev/console" "rw,nosuid,noexec,relatime" "devpts" "devpts" "rw,gid=3,mode=620,ptmxmode=666")
       (ent "/" "/dev/mqueue" "rw,nosuid,nodev,noexec,relatime" "mqueue" "mqueue" "rw")
       (ent "/" "/dev/shm" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,uid=1000005,gid=1000005")
+      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000005,gid=1000005")
+      (ent "/tmp/hakurei.0/runtime/5" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/tmp/hakurei.0/tmpdir/5" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000005,gid=1000005")
+      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000005,gid=1000005")
+      (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 "/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")
@@ -255,14 +263,6 @@ in
       (ent "/var/tmp" "/var/tmp" "rw,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 "/var/lib/hakurei/u0/a5" "/var/lib/hakurei/u0/a5" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000005,gid=1000005")
-      (ent "/tmp/hakurei.0/runtime/5" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/tmp/hakurei.0/tmpdir/5" "/tmp" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent ignore "/etc/passwd" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000005,gid=1000005")
-      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000005,gid=1000005")
-      (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")
     ];
 
     seccomp = true;

test/sandbox/case/preset.nix

@@ -54,7 +54,7 @@ in
       "WAYLAND_DISPLAY=wayland-0"
       "XDG_RUNTIME_DIR=/run/user/65534"
       "XDG_SESSION_CLASS=user"
-      "XDG_SESSION_TYPE=tty"
+      "XDG_SESSION_TYPE=wayland"
     ];
 
     fs = fs "dead" {
@@ -241,6 +241,14 @@ in
       (ent "/" "/dev/pts" "rw,nosuid,noexec,relatime" "devpts" "devpts" "rw,mode=620,ptmxmode=666")
       (ent "/" "/dev/mqueue" "rw,nosuid,nodev,noexec,relatime" "mqueue" "mqueue" "rw")
       (ent "/" "/dev/shm" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,uid=1000001,gid=1000001")
+      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000001,gid=1000001")
+      (ent "/tmp/hakurei.0/runtime/1" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/tmp/hakurei.0/tmpdir/1" "/tmp" "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")
+      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000001,gid=1000001")
+      (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 "/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")
@@ -253,14 +261,6 @@ in
       (ent "/var/tmp" "/var/tmp" "rw,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 "/var/lib/hakurei/u0/a1" "/var/lib/hakurei/u0/a1" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000001,gid=1000001")
-      (ent "/tmp/hakurei.0/runtime/1" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/tmp/hakurei.0/tmpdir/1" "/tmp" "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")
-      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000001,gid=1000001")
-      (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")
     ];
 
     seccomp = true;

test/sandbox/case/tty.nix

@@ -55,7 +55,7 @@ in
       "WAYLAND_DISPLAY=wayland-0"
       "XDG_RUNTIME_DIR=/run/user/65534"
       "XDG_SESSION_CLASS=user"
-      "XDG_SESSION_TYPE=tty"
+      "XDG_SESSION_TYPE=wayland"
     ];
 
     fs = fs "dead" {
@@ -250,6 +250,15 @@ in
       (ent ignore "/dev/console" "rw,nosuid,noexec,relatime" "devpts" "devpts" "rw,gid=3,mode=620,ptmxmode=666")
       (ent "/" "/dev/mqueue" "rw,nosuid,nodev,noexec,relatime" "mqueue" "mqueue" "rw")
       (ent "/" "/dev/shm" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,uid=1000002,gid=1000002")
+      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000002,gid=1000002")
+      (ent "/tmp/hakurei.0/runtime/2" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/tmp/hakurei.0/tmpdir/2" "/tmp" "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")
+      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000002,gid=1000002")
+      (ent ignore "/run/user/65534/wayland-0" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
+      (ent "/tmp/.X11-unix" "/tmp/.X11-unix" "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 "/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")
@@ -265,15 +274,6 @@ in
       (ent "/" "/.hakurei/store" "rw,relatime" "overlay" "overlay" "rw,lowerdir=/host/nix/.ro-store:/host/nix/.rw-store/upper,upperdir=/host/tmp/.hakurei-store-rw/upper,workdir=/host/tmp/.hakurei-store-rw/work,redirect_dir=nofollow,uuid=on,userxattr")
       (ent "/etc" ignore "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
       (ent "/var/lib/hakurei/u0/a2" "/var/lib/hakurei/u0/a2" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/" "/run/user" "rw,nosuid,nodev,relatime" "tmpfs" "ephemeral" "rw,size=4k,mode=755,uid=1000002,gid=1000002")
-      (ent "/tmp/hakurei.0/runtime/2" "/run/user/65534" "rw,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/tmp/hakurei.0/tmpdir/2" "/tmp" "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")
-      (ent ignore "/etc/group" "ro,nosuid,nodev,relatime" "tmpfs" "rootfs" "rw,uid=1000002,gid=1000002")
-      (ent ignore "/run/user/65534/wayland-0" "ro,nosuid,nodev,relatime" "ext4" "/dev/disk/by-label/nixos" "rw")
-      (ent "/tmp/.X11-unix" "/tmp/.X11-unix" "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")
     ];
 
     seccomp = true;