cmd: shim and init into separate binaries

This change also fixes a deadlock when shim fails to connect and complete the setup.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

internal/app/app.go

@@ -3,8 +3,8 @@ package app
 import (
 	"sync"
 
-	"git.ophivana.moe/security/fortify/internal"
-	"git.ophivana.moe/security/fortify/internal/shim"
+	"git.ophivana.moe/security/fortify/cmd/fshim/ipc/shim"
+	"git.ophivana.moe/security/fortify/internal/linux"
 )
 
 type App interface {
@@ -25,7 +25,7 @@ type app struct {
 	// application unique identifier
 	id *ID
 	// operating system interface
-	os internal.System
+	os linux.System
 	// shim process manager
 	shim *shim.Shim
 	// child process related information
@@ -63,7 +63,7 @@ func (a *app) WaitErr() error {
 	return a.waitErr
 }
 
-func New(os internal.System) (App, error) {
+func New(os linux.System) (App, error) {
 	a := new(app)
 	a.id = new(ID)
 	a.os = os

internal/app/app_nixos_test.go

@@ -9,8 +9,8 @@ import (
 	"git.ophivana.moe/security/fortify/acl"
 	"git.ophivana.moe/security/fortify/dbus"
 	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
 	"git.ophivana.moe/security/fortify/internal/app"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
@@ -579,8 +579,12 @@ func (s *stubNixOS) Exit(code int) {
 	panic("called exit on stub with code " + strconv.Itoa(code))
 }
 
-func (s *stubNixOS) Paths() internal.Paths {
-	return internal.Paths{
+func (s *stubNixOS) FshimPath() string {
+	return "/nix/store/00000000000000000000000000000000-fortify-0.0.10/bin/.fshim"
+}
+
+func (s *stubNixOS) Paths() linux.Paths {
+	return linux.Paths{
 		SharePath:   "/tmp/fortify.1971",
 		RuntimePath: "/run/user/1971",
 		RunDirPath:  "/run/user/1971/fortify",

internal/app/app_test.go

@@ -7,14 +7,14 @@ import (
 	"time"
 
 	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
 	"git.ophivana.moe/security/fortify/internal/app"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
 type sealTestCase struct {
 	name      string
-	os        internal.System
+	os        linux.System
 	config    *app.Config
 	id        app.ID
 	wantSys   *system.I

internal/app/export_test.go

@@ -2,11 +2,11 @@ package app
 
 import (
 	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
-func NewWithID(id ID, os internal.System) App {
+func NewWithID(id ID, os linux.System) App {
 	a := new(app)
 	a.id = &id
 	a.os = os

internal/app/launch.machinectl.go

@@ -47,8 +47,8 @@ func (a *app) commandBuilderMachineCtl(shimEnv string) (args []string) {
 	}
 	innerCommand.WriteString("; ")
 
-	// launch fortify as shim
-	innerCommand.WriteString("exec " + a.seal.sys.executable + " shim")
+	// launch fortify shim
+	innerCommand.WriteString("exec " + a.os.FshimPath())
 
 	// append inner command
 	args = append(args, innerCommand.String())

internal/app/launch.sudo.go

@@ -24,7 +24,7 @@ func (a *app) commandBuilderSudo(shimEnv string) (args []string) {
 	args = append(args, shimEnv)
 
 	// -- $@
-	args = append(args, "--", a.seal.sys.executable, "shim")
+	args = append(args, "--", a.os.FshimPath())
 
 	return
 }

internal/app/seal.go

@@ -7,10 +7,10 @@ import (
 	"path"
 	"strconv"
 
+	shim "git.ophivana.moe/security/fortify/cmd/fshim/ipc"
 	"git.ophivana.moe/security/fortify/dbus"
-	"git.ophivana.moe/security/fortify/internal"
 	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/shim"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/state"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
@@ -66,7 +66,7 @@ type appSeal struct {
 	// seal system-level component
 	sys *appSealSys
 
-	internal.Paths
+	linux.Paths
 
 	// protected by upstream mutex
 }
@@ -127,13 +127,6 @@ func (a *app) Seal(config *Config) error {
 	// create seal system component
 	seal.sys = new(appSealSys)
 
-	// look up fortify executable path
-	if p, err := a.os.Executable(); err != nil {
-		return fmsg.WrapErrorSuffix(err, "cannot look up fortify executable path:")
-	} else {
-		seal.sys.executable = p
-	}
-
 	// look up user from system
 	if u, err := a.os.Lookup(config.User); err != nil {
 		if errors.As(err, new(user.UnknownUserError)) {

internal/app/share.display.go

@@ -5,8 +5,8 @@ import (
 	"path"
 
 	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal"
 	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
@@ -23,7 +23,7 @@ var (
 	ErrXDisplay = errors.New(display + " unset")
 )
 
-func (seal *appSeal) shareDisplay(os internal.System) error {
+func (seal *appSeal) shareDisplay(os linux.System) error {
 	// pass $TERM to launcher
 	if t, ok := os.LookupEnv(term); ok {
 		seal.sys.bwrap.SetEnv[term] = t

internal/app/share.pulse.go

@@ -6,8 +6,8 @@ import (
 	"io/fs"
 	"path"
 
-	"git.ophivana.moe/security/fortify/internal"
 	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
@@ -25,7 +25,7 @@ var (
 	ErrPulseMode   = errors.New("unexpected pulse socket mode")
 )
 
-func (seal *appSeal) sharePulse(os internal.System) error {
+func (seal *appSeal) sharePulse(os linux.System) error {
 	if !seal.et.Has(system.EPulse) {
 		return nil
 	}
@@ -78,7 +78,7 @@ func (seal *appSeal) sharePulse(os internal.System) error {
 }
 
 // discoverPulseCookie attempts various standard methods to discover the current user's PulseAudio authentication cookie
-func discoverPulseCookie(os internal.System) (string, error) {
+func discoverPulseCookie(os linux.System) (string, error) {
 	if p, ok := os.LookupEnv(pulseCookie); ok {
 		return p, nil
 	}

internal/app/share.system.go

@@ -4,7 +4,7 @@ import (
 	"path"
 
 	"git.ophivana.moe/security/fortify/acl"
-	"git.ophivana.moe/security/fortify/internal"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
@@ -38,7 +38,7 @@ func (seal *appSeal) shareSystem() {
 	seal.sys.bwrap.Tmpfs(seal.SharePath, 1*1024*1024)
 }
 
-func (seal *appSeal) sharePasswd(os internal.System) {
+func (seal *appSeal) sharePasswd(os linux.System) {
 	// look up shell
 	sh := "/bin/sh"
 	if s, ok := os.LookupEnv(shell); ok {

internal/app/start.go

@@ -8,9 +8,10 @@ import (
 	"path/filepath"
 	"strings"
 
+	shim0 "git.ophivana.moe/security/fortify/cmd/fshim/ipc"
+	"git.ophivana.moe/security/fortify/cmd/fshim/ipc/shim"
 	"git.ophivana.moe/security/fortify/helper"
 	"git.ophivana.moe/security/fortify/internal/fmsg"
-	"git.ophivana.moe/security/fortify/internal/shim"
 	"git.ophivana.moe/security/fortify/internal/state"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
@@ -22,9 +23,9 @@ func (a *app) Start() error {
 	defer a.lock.Unlock()
 
 	// resolve exec paths
-	shimExec := [3]string{a.seal.sys.executable, helper.BubblewrapName}
+	shimExec := [2]string{helper.BubblewrapName}
 	if len(a.seal.command) > 0 {
-		shimExec[2] = a.seal.command[0]
+		shimExec[1] = a.seal.command[0]
 	}
 	for i, n := range shimExec {
 		if len(n) == 0 {
@@ -53,7 +54,7 @@ func (a *app) Start() error {
 
 	// construct shim manager
 	a.shim = shim.New(a.seal.toolPath, uint32(a.seal.sys.UID()), path.Join(a.seal.share, "shim"), a.seal.wl,
-		&shim.Payload{
+		&shim0.Payload{
 			Argv:  a.seal.command,
 			Exec:  shimExec,
 			Bwrap: a.seal.sys.bwrap,

internal/app/system.go

@@ -5,7 +5,7 @@ import (
 
 	"git.ophivana.moe/security/fortify/dbus"
 	"git.ophivana.moe/security/fortify/helper/bwrap"
-	"git.ophivana.moe/security/fortify/internal"
+	"git.ophivana.moe/security/fortify/internal/linux"
 	"git.ophivana.moe/security/fortify/internal/system"
 )
 
@@ -17,8 +17,6 @@ type appSealSys struct {
 
 	// default formatted XDG_RUNTIME_DIR of User
 	runtime string
-	// sealed path to fortify executable, used by shim
-	executable string
 	// target user sealed from config
 	user *user.User
 
@@ -30,7 +28,7 @@ type appSealSys struct {
 }
 
 // shareAll calls all share methods in sequence
-func (seal *appSeal) shareAll(bus [2]*dbus.Config, os internal.System) error {
+func (seal *appSeal) shareAll(bus [2]*dbus.Config, os linux.System) error {
 	if seal.shared {
 		panic("seal shared twice")
 	}