fortify: implement cleaner argument structure

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

1 files changed, 187 insertions, 12 deletions

diff --git a/main.go b/main.go
index 309af765..7c0a218d 100644
--- a/main.go
+++ b/main.go
@@ -1,16 +1,26 @@
 package main
 
 import (
+	_ "embed"
+	"encoding/json"
 	"flag"
+	"fmt"
+	"text/tabwriter"
 
+	"git.ophivana.moe/security/fortify/dbus"
 	"git.ophivana.moe/security/fortify/internal"
 	"git.ophivana.moe/security/fortify/internal/app"
 	"git.ophivana.moe/security/fortify/internal/fmsg"
 	"git.ophivana.moe/security/fortify/internal/linux"
+	"git.ophivana.moe/security/fortify/internal/state"
+	"git.ophivana.moe/security/fortify/internal/system"
 )
 
 var (
 	flagVerbose bool
+
+	//go:embed LICENSE
+	license string
 )
 
 func init() {
@@ -28,29 +38,193 @@ func main() {
 	flag.Parse()
 	fmsg.SetVerbose(flagVerbose)
 
-	if os.SdBooted() {
-		fmsg.VPrintln("system booted with systemd as init system")
-	}
-
 	// root check
 	if os.Geteuid() == 0 {
 		fmsg.Fatal("this program must not run as root")
 		panic("unreachable")
 	}
 
-	// version/license/template command early exit
-	tryVersion()
-	tryLicense()
-	tryTemplate()
+	printHelp := func() {
+		fmt.Println()
+		fmt.Println("Usage:\tfortify [-v] COMMAND [OPTIONS]")
+		fmt.Println()
+		fmt.Println("Commands:")
+		w := tabwriter.NewWriter(os.Stdout(), 0, 1, 4, ' ', 0)
+		commands := [][2]string{
+			{"app", "Launch app defined by the specified config file"},
+			{"run", "Configure and start a permissive default sandbox"},
+			{"ps", "List active apps and their state"},
+			{"version", "Show fortify version"},
+			{"license", "Show full license text"},
+			{"template", "Produce a config template"},
+			{"help", "Show this help message"},
+		}
+		for _, c := range commands {
+			_, _ = fmt.Fprintf(w, "\t%s\t%s\n", c[0], c[1])
+		}
+		if err := w.Flush(); err != nil {
+			fmsg.Fatalf("cannot print help: %v", err)
+		}
+		fmt.Println()
+	}
+
+	args := flag.Args()
+	if len(args) == 0 {
+		printHelp()
+		fmsg.Exit(0)
+	}
+
+	switch args[0] {
+	case "version": // print version string
+		if v, ok := internal.Check(internal.Version); ok {
+			fmt.Println(v)
+		} else {
+			fmt.Println("impure")
+		}
+		fmsg.Exit(0)
+	case "license": // print embedded license
+		fmt.Println(license)
+		fmsg.Exit(0)
+	case "template": // print full template configuration
+		if s, err := json.MarshalIndent(app.Template(), "", "  "); err != nil {
+			fmsg.Fatalf("cannot generate template: %v", err)
+			panic("unreachable")
+		} else {
+			fmt.Println(string(s))
+		}
+		fmsg.Exit(0)
+	case "help": // print help message
+		printHelp()
+		fmsg.Exit(0)
+	case "ps": // print all state info
+		var w *tabwriter.Writer
+		state.MustPrintLauncherStateSimpleGlobal(&w, os.Paths().RunDirPath)
+		if w != nil {
+			if err := w.Flush(); err != nil {
+				fmsg.Println("cannot format output:", err)
+			}
+		} else {
+			fmt.Println("No information available")
+		}
+
+		fmsg.Exit(0)
+	case "app": // launch app from configuration file
+		if len(args) < 2 {
+			fmsg.Fatal("app requires at least 1 argument")
+		}
+
+		config := new(app.Config)
+		if f, err := os.Open(args[1]); err != nil {
+			fmsg.Fatalf("cannot access config file %q: %s", args[1], err)
+			panic("unreachable")
+		} else if err = json.NewDecoder(f).Decode(&config); err != nil {
+			fmsg.Fatalf("cannot parse config file %q: %s", args[1], err)
+			panic("unreachable")
+		}
+
+		// append extra args
+		config.Command = append(config.Command, args[2:]...)
+
+		// invoke app
+		runApp(config)
+	case "run": // run app in permissive defaults usage pattern
+		set := flag.NewFlagSet("run", flag.ExitOnError)
+
+		var (
+			dbusConfigSession string
+			dbusConfigSystem  string
+			dbusID            string
+			mpris             bool
+			dbusVerbose       bool
+
+			userName    string
+			enablements [system.ELen]bool
+
+			launchMethodText string
+		)
+
+		set.StringVar(&dbusConfigSession, "dbus-config", "builtin", "Path to D-Bus proxy config file, or \"builtin\" for defaults")
+		set.StringVar(&dbusConfigSystem, "dbus-system", "nil", "Path to system D-Bus proxy config file, or \"nil\" to disable")
+		set.StringVar(&dbusID, "dbus-id", "", "D-Bus ID of application, leave empty to disable own paths, has no effect if custom config is available")
+		set.BoolVar(&mpris, "mpris", false, "Allow owning MPRIS D-Bus path, has no effect if custom config is available")
+		set.BoolVar(&dbusVerbose, "dbus-log", false, "Force logging in the D-Bus proxy")
+
+		set.StringVar(&userName, "u", "chronos", "Passwd name of user to run as")
+		set.BoolVar(&enablements[system.EWayland], "wayland", false, "Share Wayland socket")
+		set.BoolVar(&enablements[system.EX11], "X", false, "Share X11 socket and allow connection")
+		set.BoolVar(&enablements[system.EDBus], "dbus", false, "Proxy D-Bus connection")
+		set.BoolVar(&enablements[system.EPulse], "pulse", false, "Share PulseAudio socket and cookie")
+
+		methodHelpString := "Method of launching the child process, can be one of \"sudo\""
+		if os.SdBooted() {
+			methodHelpString += ", \"systemd\""
+		}
+		set.StringVar(&launchMethodText, "method", "sudo", methodHelpString)
+
+		// Ignore errors; set is set for ExitOnError.
+		_ = set.Parse(args[1:])
+
+		// initialise config from flags
+		config := &app.Config{
+			ID:      dbusID,
+			User:    userName,
+			Command: set.Args(),
+			Method:  launchMethodText,
+		}
+
+		// enablements from flags
+		for i := system.Enablement(0); i < system.Enablement(system.ELen); i++ {
+			if enablements[i] {
+				config.Confinement.Enablements.Set(i)
+			}
+		}
+
+		// parse D-Bus config file from flags if applicable
+		if enablements[system.EDBus] {
+			if dbusConfigSession == "builtin" {
+				config.Confinement.SessionBus = dbus.NewConfig(dbusID, true, mpris)
+			} else {
+				if c, err := dbus.NewConfigFromFile(dbusConfigSession); err != nil {
+					fmsg.Fatalf("cannot load session bus proxy config from %q: %s", dbusConfigSession, err)
+				} else {
+					config.Confinement.SessionBus = c
+				}
+			}
+
+			// system bus proxy is optional
+			if dbusConfigSystem != "nil" {
+				if c, err := dbus.NewConfigFromFile(dbusConfigSystem); err != nil {
+					fmsg.Fatalf("cannot load system bus proxy config from %q: %s", dbusConfigSystem, err)
+				} else {
+					config.Confinement.SystemBus = c
+				}
+			}
+
+			// override log from configuration
+			if dbusVerbose {
+				config.Confinement.SessionBus.Log = true
+				config.Confinement.SystemBus.Log = true
+			}
+		}
+
+		// invoke app
+		runApp(config)
+	default:
+		fmsg.Fatalf("%q is not a valid command", args[0])
+	}
+
+	panic("unreachable")
+}
 
-	// state query command early exit
-	tryState()
+func runApp(config *app.Config) {
+	if os.SdBooted() {
+		fmsg.VPrintln("system booted with systemd as init system")
+	}
 
-	// invoke app
 	a, err := app.New(os)
 	if err != nil {
 		fmsg.Fatalf("cannot create app: %s\n", err)
-	} else if err = a.Seal(loadConfig()); err != nil {
+	} else if err = a.Seal(config); err != nil {
 		logBaseError(err, "cannot seal app:")
 		fmsg.Exit(1)
 	} else if err = a.Start(); err != nil {
@@ -69,4 +243,5 @@ func main() {
 		fmsg.Println("inner wait failed:", err)
 	}
 	fmsg.Exit(r)
+	panic("unreachable")
 }