3 files changed, 289 insertions, 0 deletions
diff --git a/internal/app/builder.go b/internal/app/builder.go
new file mode 100644
index 00000000..2bce43b4
--- /dev/null
+++ b/internal/app/builder.go
@@ -0,0 +1,13 @@
+package app
+
+func (a *App) Command() []string {
+	return a.command
+}
+
+func (a *App) UID() int {
+	return a.uid
+}
+
+func (a *App) AppendEnv(k, v string) {
+	a.env = append(a.env, k+"="+v)
+}
diff --git a/internal/app/launch.go b/internal/app/launch.go
new file mode 100644
index 00000000..c6f7b773
--- /dev/null
+++ b/internal/app/launch.go
@@ -0,0 +1,152 @@
+package app
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/gob"
+	"fmt"
+	"os"
+	"strings"
+	"syscall"
+
+	"git.ophivana.moe/cat/fortify/internal/state"
+	"git.ophivana.moe/cat/fortify/internal/system"
+	"git.ophivana.moe/cat/fortify/internal/util"
+)
+
+const (
+	sudoAskPass     = "SUDO_ASKPASS"
+	launcherPayload = "FORTIFY_LAUNCHER_PAYLOAD"
+)
+
+func (a *App) launcherPayloadEnv() string {
+	r := &bytes.Buffer{}
+	enc := base64.NewEncoder(base64.StdEncoding, r)
+
+	if err := gob.NewEncoder(enc).Encode(a.command); err != nil {
+		state.Fatal("Error encoding launcher payload:", err)
+	}
+
+	_ = enc.Close()
+	return launcherPayload + "=" + r.String()
+}
+
+// Early hidden launcher path
+func Early(printVersion bool) {
+	if printVersion {
+		if r, ok := os.LookupEnv(launcherPayload); ok {
+			dec := base64.NewDecoder(base64.StdEncoding, strings.NewReader(r))
+
+			var argv []string
+			if err := gob.NewDecoder(dec).Decode(&argv); err != nil {
+				fmt.Println("Error decoding launcher payload:", err)
+				os.Exit(1)
+			}
+
+			if err := os.Unsetenv(launcherPayload); err != nil {
+				fmt.Println("Error unsetting launcher payload:", err)
+				// not fatal, do not fail
+			}
+
+			var p string
+
+			if len(argv) > 0 {
+				if p, ok = util.Which(argv[0]); !ok {
+					fmt.Printf("Did not find '%s' in PATH\n", argv[0])
+					os.Exit(1)
+				}
+			} else {
+				if p, ok = os.LookupEnv("SHELL"); !ok {
+					fmt.Println("No command was specified and $SHELL was unset")
+					os.Exit(1)
+				}
+			}
+
+			if err := syscall.Exec(p, argv, os.Environ()); err != nil {
+				fmt.Println("Error executing launcher payload:", err)
+				os.Exit(1)
+			}
+
+			// unreachable
+			os.Exit(1)
+			return
+		}
+	}
+}
+
+func (a *App) launchBySudo() (args []string) {
+	args = make([]string, 0, 4+len(a.env)+len(a.command))
+
+	// -Hiu $USER
+	args = append(args, "-Hiu", a.Username)
+
+	// -A?
+	if _, ok := os.LookupEnv(sudoAskPass); ok {
+		if system.V.Verbose {
+			fmt.Printf("%s set, adding askpass flag\n", sudoAskPass)
+		}
+		args = append(args, "-A")
+	}
+
+	// environ
+	args = append(args, a.env...)
+
+	// -- $@
+	args = append(args, "--")
+	args = append(args, a.command...)
+
+	return
+}
+
+func (a *App) launchByMachineCtl(bare bool) (args []string) {
+	args = make([]string, 0, 9+len(a.env))
+
+	// shell --uid=$USER
+	args = append(args, "shell", "--uid="+a.Username)
+
+	// --quiet
+	if !system.V.Verbose {
+		args = append(args, "--quiet")
+	}
+
+	// environ
+	envQ := make([]string, len(a.env)+1)
+	for i, e := range a.env {
+		envQ[i] = "-E" + e
+	}
+	envQ[len(a.env)] = "-E" + a.launcherPayloadEnv()
+	args = append(args, envQ...)
+
+	// -- .host
+	args = append(args, "--", ".host")
+
+	// /bin/sh -c
+	if sh, ok := util.Which("sh"); !ok {
+		state.Fatal("Did not find 'sh' in PATH")
+	} else {
+		args = append(args, sh, "-c")
+	}
+
+	if len(a.command) == 0 { // execute shell if command is not provided
+		a.command = []string{"$SHELL"}
+	}
+
+	innerCommand := strings.Builder{}
+
+	if !bare {
+		innerCommand.WriteString("dbus-update-activation-environment --systemd")
+		for _, e := range a.env {
+			innerCommand.WriteString(" " + strings.SplitN(e, "=", 2)[0])
+		}
+		innerCommand.WriteString("; systemctl --user start xdg-desktop-portal-gtk; ")
+	}
+
+	if executable, err := os.Executable(); err != nil {
+		state.Fatal("Error reading executable path:", err)
+	} else {
+		innerCommand.WriteString("exec " + executable + " -V")
+	}
+	args = append(args, innerCommand.String())
+
+	return
+}
diff --git a/internal/app/setup.go b/internal/app/setup.go
new file mode 100644
index 00000000..7b5cd2ec
--- /dev/null
+++ b/internal/app/setup.go
@@ -0,0 +1,124 @@
+package app
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"os/user"
+	"strconv"
+
+	"git.ophivana.moe/cat/fortify/internal/state"
+	"git.ophivana.moe/cat/fortify/internal/system"
+	"git.ophivana.moe/cat/fortify/internal/util"
+)
+
+type App struct {
+	uid     int
+	env     []string
+	command []string
+
+	*user.User
+}
+
+func (a *App) Run() {
+	f := a.launchBySudo
+	m, b := false, false
+	switch {
+	case system.MethodFlags[0]: // sudo
+	case system.MethodFlags[1]: // bare
+		m, b = true, true
+	default: // machinectl
+		m, b = true, false
+	}
+
+	var toolPath string
+
+	// dependency checks
+	const sudoFallback = "Falling back to 'sudo', some desktop integration features may not work"
+	if m {
+		if !util.SdBooted() {
+			fmt.Println("This system was not booted through systemd")
+			fmt.Println(sudoFallback)
+		} else if tp, ok := util.Which("machinectl"); !ok {
+			fmt.Println("Did not find 'machinectl' in PATH")
+			fmt.Println(sudoFallback)
+		} else {
+			toolPath = tp
+			f = func() []string { return a.launchByMachineCtl(b) }
+		}
+	} else if tp, ok := util.Which("sudo"); !ok {
+		state.Fatal("Did not find 'sudo' in PATH")
+	} else {
+		toolPath = tp
+	}
+
+	if system.V.Verbose {
+		fmt.Printf("Selected launcher '%s' bare=%t\n", toolPath, b)
+	}
+
+	cmd := exec.Command(toolPath, f()...)
+	cmd.Env = a.env
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Dir = system.V.RunDir
+
+	if system.V.Verbose {
+		fmt.Println("Executing:", cmd)
+	}
+
+	if err := cmd.Start(); err != nil {
+		state.Fatal("Error starting process:", err)
+	}
+
+	if err := state.SaveProcess(a.Uid, cmd); err != nil {
+		// process already started, shouldn't be fatal
+		fmt.Println("Error registering process:", err)
+	}
+
+	var r int
+	if err := cmd.Wait(); err != nil {
+		var exitError *exec.ExitError
+		if !errors.As(err, &exitError) {
+			state.Fatal("Error running process:", err)
+		}
+	}
+
+	if system.V.Verbose {
+		fmt.Println("Process exited with exit code", r)
+	}
+	state.BeforeExit()
+	os.Exit(r)
+}
+
+func New(userName string, args []string) *App {
+	a := &App{command: args}
+
+	if u, err := user.Lookup(userName); err != nil {
+		if errors.As(err, new(user.UnknownUserError)) {
+			fmt.Println("unknown user", userName)
+		} else {
+			// unreachable
+			panic(err)
+		}
+
+		// too early for fatal
+		os.Exit(1)
+	} else {
+		a.User = u
+	}
+
+	if u, err := strconv.Atoi(a.Uid); err != nil {
+		// usually unreachable
+		panic("uid parse")
+	} else {
+		a.uid = u
+	}
+
+	if system.V.Verbose {
+		fmt.Println("Running as user", a.Username, "("+a.Uid+"),", "command:", a.command)
+	}
+
+	return a
+}