fortify: clean up config loading

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

config.go

@@ -1,9 +1,14 @@
 package main
 
 import (
+	"encoding/json"
 	"flag"
+	"os"
 
+	"git.ophivana.moe/cat/fortify/dbus"
 	"git.ophivana.moe/cat/fortify/internal"
+	"git.ophivana.moe/cat/fortify/internal/app"
+	"git.ophivana.moe/cat/fortify/internal/state"
 )
 
 var (
@@ -11,15 +16,12 @@ var (
 
 	dbusConfigSession string
 	dbusConfigSystem  string
-	dbusVerbose       bool
 	dbusID            string
 	mpris             bool
+	dbusVerbose       bool
 
 	userName    string
-	mustWayland bool
-	mustX       bool
-	mustDBus    bool
-	mustPulse   bool
+	enablements [state.EnableLength]bool
 
 	launchMethodText string
 )
@@ -30,15 +32,15 @@ func init() {
 
 	flag.StringVar(&dbusConfigSession, "dbus-config", "builtin", "Path to D-Bus proxy config file, or \"builtin\" for defaults")
 	flag.StringVar(&dbusConfigSystem, "dbus-system", "nil", "Path to system D-Bus proxy config file, or \"nil\" to disable")
-	flag.BoolVar(&dbusVerbose, "dbus-log", false, "Enable logging in the D-Bus proxy")
 	flag.StringVar(&dbusID, "dbus-id", "", "D-Bus ID of application, leave empty to disable own paths, has no effect if custom config is available")
 	flag.BoolVar(&mpris, "mpris", false, "Allow owning MPRIS D-Bus path, has no effect if custom config is available")
+	flag.BoolVar(&dbusVerbose, "dbus-log", false, "Force logging in the D-Bus proxy")
 
 	flag.StringVar(&userName, "u", "chronos", "Passwd name of user to run as")
-	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(&enablements[state.EnableWayland], "wayland", false, "Share Wayland socket")
+	flag.BoolVar(&enablements[state.EnableX], "X", false, "Share X11 socket and allow connection")
+	flag.BoolVar(&enablements[state.EnableDBus], "dbus", false, "Proxy D-Bus connection")
+	flag.BoolVar(&enablements[state.EnablePulse], "pulse", false, "Share PulseAudio socket and cookie")
 }
 
 func init() {
@@ -49,3 +51,69 @@ func init() {
 
 	flag.StringVar(&launchMethodText, "method", "sudo", methodHelpString)
 }
+
+func loadConfig() *app.Config {
+	if confPath == "nil" {
+		// config from flags
+		return configFromFlags()
+	} else {
+		// config from file
+		c := new(app.Config)
+		if f, err := os.Open(confPath); err != nil {
+			fatalf("cannot access config file '%s': %s\n", confPath, err)
+			panic("unreachable")
+		} else if err = json.NewDecoder(f).Decode(&c); err != nil {
+			fatalf("cannot parse config file '%s': %s\n", confPath, err)
+			panic("unreachable")
+		} else {
+			return c
+		}
+	}
+}
+
+func configFromFlags() (config *app.Config) {
+	// initialise config from flags
+	config = &app.Config{
+		ID:      dbusID,
+		User:    userName,
+		Command: flag.Args(),
+		Method:  launchMethodText,
+	}
+
+	// enablements from flags
+	for i := state.Enablement(0); i < state.EnableLength; i++ {
+		if enablements[i] {
+			config.Confinement.Enablements.Set(i)
+		}
+	}
+
+	// parse D-Bus config file from flags if applicable
+	if enablements[state.EnableDBus] {
+		if dbusConfigSession == "builtin" {
+			config.Confinement.SessionBus = dbus.NewConfig(dbusID, true, mpris)
+		} else {
+			if c, err := dbus.NewConfigFromFile(dbusConfigSession); err != nil {
+				fatalf("cannot load session bus proxy config from %q: %s\n", dbusConfigSession, err)
+			} else {
+				config.Confinement.SessionBus = c
+			}
+		}
+
+		// system bus proxy is optional
+		if dbusConfigSystem != "nil" {
+			if c, err := dbus.NewConfigFromFile(dbusConfigSystem); err != nil {
+				fatalf("cannot load system bus proxy config from %q: %s\n", dbusConfigSystem, err)
+			} else {
+				config.Confinement.SystemBus = c
+			}
+		}
+
+		// override log from configuration
+		if dbusVerbose {
+			config.Confinement.SessionBus.Log = true
+			config.Confinement.SystemBus.Log = true
+		}
+	}
+
+	return
+}