hst: check for insecure PulseAudio enablement

This is currently still a noop, but required for #26.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/hpkg/build.nix

@@ -45,7 +45,7 @@
   allow_wayland ? true,
   allow_x11 ? false,
   allow_dbus ? true,
-  allow_pulse ? true,
+  allow_audio ? true,
   gpu ? allow_wayland || allow_x11,
 }:
 
@@ -175,7 +175,8 @@ let
       wayland = allow_wayland;
       x11 = allow_x11;
       dbus = allow_dbus;
-      pulse = allow_pulse;
+      pipewire = allow_audio;
+      pulse = allow_audio;
     };
 
     mesa = if gpu then mesaWrappers else null;

cmd/hpkg/test/test.py

@@ -90,7 +90,7 @@ wait_for_window("hakurei@machine-foot")
 machine.send_chars("clear; wayland-info && touch /tmp/success-client\n")
 machine.wait_for_file("/tmp/hakurei.0/tmpdir/2/success-client")
 collect_state_ui("app_wayland")
-check_state("foot", {"wayland": True, "dbus": True, "pulse": True})
+check_state("foot", {"wayland": True, "dbus": True, "pipewire": True, "pulse": True})
 # Verify acl on XDG_RUNTIME_DIR:
 print(machine.succeed("getfacl --absolute-names --omit-header --numeric /run/user/1000 | grep 10002"))
 machine.send_chars("exit\n")

hst/config.go

@@ -60,6 +60,9 @@ var (
 
 	// ErrEnviron is returned by [Config.Validate] if an environment variable name contains '=' or NUL.
 	ErrEnviron = errors.New("invalid environment variable name")
+
+	// ErrInsecure is returned by [Config.Validate] if the configuration is considered insecure.
+	ErrInsecure = errors.New("configuration is insecure")
 )
 
 // Validate checks [Config] and returns [AppError] if an invalid value is encountered.
@@ -106,6 +109,13 @@ func (config *Config) Validate() error {
 		}
 	}
 
+	// EPulse without EPipeWire is insecure
+	if et := config.Enablements.Unwrap(); !config.DirectPulse &&
+		et&EPipeWire == 0 && et&EPulse != 0 {
+		return &AppError{Step: "validate configuration", Err: ErrInsecure,
+			Msg: "enablement PulseAudio requires PipeWire, which is not set"}
+	}
+
 	return nil
 }
 

hst/config_test.go

@@ -53,6 +53,12 @@ func TestConfigValidate(t *testing.T) {
 			Env:   map[string]string{"TERM\x00": ""},
 		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrEnviron,
 			Msg: `invalid environment variable "TERM\x00"`}},
+		{"insecure pulse", &hst.Config{Enablements: hst.NewEnablements(hst.EPulse), Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrInsecure,
+			Msg: "enablement PulseAudio requires PipeWire, which is not set"}},
 		{"valid", &hst.Config{Container: &hst.ContainerConfig{
 			Home:  fhs.AbsTmp,
 			Shell: fhs.AbsTmp,

hst/hst.go

@@ -92,7 +92,6 @@ func Template() *Config {
 			Log:       false,
 			Filter:    true,
 		},
-		DirectWayland: false,
 
 		ExtraPerms: []ExtraPermConfig{
 			{Path: fhs.AbsVarLib.Append("hakurei/u0"), Ensure: true, Execute: true},

options.nix

@@ -218,7 +218,7 @@ in
                   type = nullOr bool;
                   default = true;
                   description = ''
-                    Whether to share the Wayland socket.
+                    Whether to share the Wayland server via security-context-v1.
                   '';
                 };
 
@@ -238,11 +238,19 @@ in
                   '';
                 };
 
+                pipewire = mkOption {
+                  type = nullOr bool;
+                  default = true;
+                  description = ''
+                    Whether to share the PipeWire server via SecurityContext.
+                  '';
+                };
+
                 pulse = mkOption {
                   type = nullOr bool;
                   default = true;
                   description = ''
-                    Whether to share the PulseAudio socket and cookie.
+                    Whether to run the PulseAudio compatibility daemon.
                   '';
                 };
               };

test/configuration.nix

@@ -133,6 +133,7 @@
         wait_delay = 1;
         enablements = {
           wayland = false;
+          pipewire = false;
           pulse = false;
         };
       };
@@ -152,6 +153,7 @@
         command = "foot";
         enablements = {
           dbus = false;
+          pipewire = false;
           pulse = false;
         };
       };
@@ -167,6 +169,7 @@
         command = "foot";
         enablements = {
           dbus = false;
+          pipewire = false;
           pulse = false;
         };
       };
@@ -199,6 +202,7 @@
           wayland = false;
           x11 = true;
           dbus = false;
+          pipewire = false;
           pulse = false;
         };
       };
@@ -218,6 +222,7 @@
         command = "foot";
         enablements = {
           dbus = false;
+          pipewire = false;
           pulse = false;
         };
       };
@@ -232,6 +237,7 @@
           wayland = false;
           x11 = false;
           dbus = false;
+          pipewire = false;
           pulse = false;
         };
       };

test/test.py

@@ -225,7 +225,7 @@ wait_for_window(f"u0_a{hakurei_identity(1)}@machine")
 machine.send_chars("clear; pactl info && touch /var/tmp/pulse-ok\n")
 machine.wait_for_file("/var/tmp/pulse-ok", timeout=15)
 collect_state_ui("pulse_wayland")
-check_state("pa-foot", {"wayland": True, "pulse": True})
+check_state("pa-foot", {"wayland": True, "pipewire": True, "pulse": True})
 machine.send_chars("exit\n")
 machine.wait_until_fails("pgrep foot", timeout=5)