clean up setup/launcher code and enable better control over shares

In the past Wayland, X and PulseAudio are shared unconditionally. This can unnecessarily increase attack surface as some of these resources might not be needed at all. This commit moves all environment preparation code to the internal app package and selectively call them based on flags.

An "enablements" bitfield is introduced tracking all enabled shares. This value is registered after successful child process launch and stored in launcher states.

Code responsible for running the child process is isolated to its own app/run file and cleaned up. Launch method selection is also extensively cleaned up.

The internal state/track readLaunchers function now takes uid as an argument. Launcher state is now printed using text/tabwriter and argv is only emitted when verbose.

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

cli.go

@@ -3,21 +3,33 @@ package main
 import (
 	"flag"
 
-	"git.ophivana.moe/cat/fortify/internal/system"
+	"git.ophivana.moe/cat/fortify/internal/app"
 )
 
 var (
-	userName     string
-	printVersion bool
-	mustPulse    bool
+	userName string
+
+	mustWayland bool
+	mustX       bool
+	mustDBus    bool
+	mustPulse   bool
+
 	flagVerbose  bool
+	printVersion bool
 )
 
 func init() {
 	flag.StringVar(&userName, "u", "chronos", "Specify a username")
-	flag.BoolVar(&system.MethodFlags[0], "sudo", false, "Use 'sudo' to change user")
-	flag.BoolVar(&system.MethodFlags[1], "bare", false, "Use 'machinectl' but skip xdg-desktop-portal setup")
-	flag.BoolVar(&mustPulse, "pulse", false, "Treat unavailable PulseAudio as fatal")
+
+	flag.BoolVar(&mustWayland, "wayland", false, "Share Wayland socket")
+	flag.BoolVar(&mustX, "X", false, "Share X11 socket and allow connection")
+	flag.BoolVar(&mustDBus, "dbus", false, "Proxy D-Bus connection")
+	flag.BoolVar(&mustPulse, "pulse", false, "Share PulseAudio socket and cookie")
+
+	flag.BoolVar(&app.LaunchOptions[app.LaunchMethodSudo], "sudo", false, "Use 'sudo' to switch user")
+	flag.BoolVar(&app.LaunchOptions[app.LaunchMethodMachineCtl], "machinectl", true, "Use 'machinectl' to switch user")
+	flag.BoolVar(&app.LaunchOptions[app.LaunchBare], "bare", false, "Only set environment variables for child")
+
 	flag.BoolVar(&flagVerbose, "v", false, "Verbose output")
 	flag.BoolVar(&printVersion, "V", false, "Print version")
 }