system/dbus: remove builder state leak

This enables external testing of system.I state.

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

internal/app/app_test.go

@@ -25,6 +25,7 @@ import (
 	"hakurei.app/message"
 	"hakurei.app/system"
 	"hakurei.app/system/acl"
+	"hakurei.app/system/dbus"
 )
 
 func TestApp(t *testing.T) {
@@ -213,7 +214,7 @@ func TestApp(t *testing.T) {
 				Ensure(m("/run/user/1971"), 0700).UpdatePermType(system.User, m("/run/user/1971"), acl.Execute). // this is ordered as is because the previous Ensure only calls mkdir if XDG_RUNTIME_DIR is unset
 				Ephemeral(system.Process, m("/run/user/1971/hakurei/ebf083d1b175911782d413369b64ce7c"), 0700).UpdatePermType(system.Process, m("/run/user/1971/hakurei/ebf083d1b175911782d413369b64ce7c"), acl.Execute).
 				Link(m("/run/user/1971/pulse/native"), m("/run/user/1971/hakurei/ebf083d1b175911782d413369b64ce7c/pulse")).
-				MustProxyDBus(m("/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/bus"), &hst.BusConfig{
+				MustProxyDBus(&hst.BusConfig{
 					Talk: []string{
 						"org.freedesktop.Notifications",
 						"org.freedesktop.FileManager1",
@@ -235,13 +236,19 @@ func TestApp(t *testing.T) {
 						"org.freedesktop.portal.*": "@/org/freedesktop/portal/*",
 					},
 					Filter: true,
-				}, m("/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/system_bus_socket"), &hst.BusConfig{
+				}, &hst.BusConfig{
 					Talk: []string{
 						"org.bluez",
 						"org.freedesktop.Avahi",
 						"org.freedesktop.UPower",
 					},
 					Filter: true,
+				}, dbus.ProxyPair{
+					"unix:path=/run/user/1971/bus",
+					"/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/bus",
+				}, dbus.ProxyPair{
+					"unix:path=/var/run/dbus/system_bus_socket",
+					"/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/system_bus_socket",
 				}).
 				UpdatePerm(m("/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/bus"), acl.Read, acl.Write).
 				UpdatePerm(m("/tmp/hakurei.0/ebf083d1b175911782d413369b64ce7c/system_bus_socket"), acl.Read, acl.Write),
@@ -364,7 +371,7 @@ func TestApp(t *testing.T) {
 				Ephemeral(system.Process, m("/run/user/1971/hakurei/8e2c76b066dabe574cf073bdb46eb5c1"), 0700).UpdatePermType(system.Process, m("/run/user/1971/hakurei/8e2c76b066dabe574cf073bdb46eb5c1"), acl.Execute).
 				Link(m("/run/user/1971/pulse/native"), m("/run/user/1971/hakurei/8e2c76b066dabe574cf073bdb46eb5c1/pulse")).
 				Ephemeral(system.Process, m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1"), 0711).
-				MustProxyDBus(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/bus"), &hst.BusConfig{
+				MustProxyDBus(&hst.BusConfig{
 					Talk: []string{
 						"org.freedesktop.FileManager1", "org.freedesktop.Notifications",
 						"org.freedesktop.ScreenSaver", "org.freedesktop.secrets",
@@ -377,13 +384,19 @@ func TestApp(t *testing.T) {
 					},
 					Call: map[string]string{}, Broadcast: map[string]string{},
 					Filter: true,
-				}, m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket"), &hst.BusConfig{
+				}, &hst.BusConfig{
 					Talk: []string{
 						"org.bluez",
 						"org.freedesktop.Avahi",
 						"org.freedesktop.UPower",
 					},
 					Filter: true,
+				}, dbus.ProxyPair{
+					"unix:path=/run/user/1971/bus",
+					"/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/bus",
+				}, dbus.ProxyPair{
+					"unix:path=/var/run/dbus/system_bus_socket",
+					"/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket",
 				}).
 				UpdatePerm(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/bus"), acl.Read, acl.Write).
 				UpdatePerm(m("/tmp/hakurei.0/8e2c76b066dabe574cf073bdb46eb5c1/system_bus_socket"), acl.Read, acl.Write),
@@ -739,6 +752,10 @@ func (k *stubNixOS) overflowGid(message.Msg) int { return 65534 }
 
 func (k *stubNixOS) mustHsuPath() *check.Absolute { return m("/proc/nonexistent/hsu") }
 
+func (k *stubNixOS) dbusAddress() (string, string) {
+	return "unix:path=/run/user/1971/bus", "unix:path=/var/run/dbus/system_bus_socket"
+}
+
 func (k *stubNixOS) fatalf(format string, v ...any) { panic(fmt.Sprintf(format, v...)) }
 
 func (k *stubNixOS) isVerbose() bool                  { return true }

internal/app/dispatcher.go

@@ -13,6 +13,7 @@ import (
 	"hakurei.app/container/check"
 	"hakurei.app/internal"
 	"hakurei.app/message"
+	"hakurei.app/system/dbus"
 )
 
 // osFile represents [os.File].
@@ -63,6 +64,9 @@ type syscallDispatcher interface {
 	// mustHsuPath provides [internal.MustHsuPath].
 	mustHsuPath() *check.Absolute
 
+	// dbusAddress provides [dbus.Address].
+	dbusAddress() (session, system string)
+
 	// fatalf provides [log.Fatalf].
 	fatalf(format string, v ...any)
 }
@@ -99,4 +103,6 @@ func (direct) overflowGid(msg message.Msg) int { return container.OverflowGid(ms
 
 func (direct) mustHsuPath() *check.Absolute { return internal.MustHsuPath() }
 
+func (k direct) dbusAddress() (session, system string) { return dbus.Address() }
+
 func (direct) fatalf(format string, v ...any) { log.Fatalf(format, v...) }

internal/app/dispatcher_test.go

@@ -97,7 +97,7 @@ func checkOpBehaviour(t *testing.T, testCases []opBehaviourTestCase) {
 				if err := s.populateLocal(k, k); err != nil {
 					t.Fatalf("populateLocal: error = %v", err)
 				}
-				stateSys := s.newSys(config, newI())
+				stateSys := s.newSys(config, system.New(panicMsgContext{}, k, checkExpectUid))
 				if tc.pStateSys != nil {
 					tc.pStateSys(stateSys)
 				}
@@ -218,6 +218,12 @@ func (k *kstub) mustHsuPath() *check.Absolute {
 	return k.Expects("mustHsuPath").Ret.(*check.Absolute)
 }
 
+func (k *kstub) dbusAddress() (session, system string) {
+	k.Helper()
+	ret := k.Expects("dbusAddress").Ret.([2]string)
+	return ret[0], ret[1]
+}
+
 func (k *kstub) GetLogger() *log.Logger { panic("unreachable") }
 
 func (k *kstub) IsVerbose() bool { k.Helper(); return k.Expects("isVerbose").Ret.(bool) }
@@ -320,4 +326,5 @@ func (panicDispatcher) cmdOutput(*exec.Cmd) ([]byte, error)   { panic("unreachab
 func (panicDispatcher) overflowUid(message.Msg) int           { panic("unreachable") }
 func (panicDispatcher) overflowGid(message.Msg) int           { panic("unreachable") }
 func (panicDispatcher) mustHsuPath() *check.Absolute          { panic("unreachable") }
+func (panicDispatcher) dbusAddress() (string, string)         { panic("unreachable") }
 func (panicDispatcher) fatalf(string, ...any)                 { panic("unreachable") }

internal/app/spdbus.go

@@ -13,8 +13,7 @@ func init() { gob.Register(new(spDBusOp)) }
 
 // spDBusOp maintains an xdg-dbus-proxy instance for the container.
 type spDBusOp struct {
-	// Whether to bind the system bus socket.
-	// Populated during toSystem.
+	// Whether to bind the system bus socket. Populated during toSystem.
 	ProxySystem bool
 }
 
@@ -30,10 +29,10 @@ func (s *spDBusOp) toSystem(state *outcomeStateSys) error {
 	// downstream socket paths
 	sessionPath, systemPath := state.instance().Append("bus"), state.instance().Append("system_bus_socket")
 
-	if err := state.sys.ProxyDBus(
-		state.sessionBus, state.systemBus,
-		sessionPath, systemPath,
-	); err != nil {
+	var sessionBus, systemBus dbus.ProxyPair
+	sessionBus[0], systemBus[0] = state.k.dbusAddress()
+	sessionBus[1], systemBus[1] = sessionPath.String(), systemPath.String()
+	if err := state.sys.ProxyDBus(state.sessionBus, state.systemBus, sessionBus, systemBus); err != nil {
 		return err
 	}
 

system/dbus.go

@@ -12,18 +12,19 @@ import (
 	"syscall"
 
 	"hakurei.app/container"
-	"hakurei.app/container/check"
 	"hakurei.app/hst"
 	"hakurei.app/system/dbus"
 )
 
-var (
-	ErrDBusConfig = errors.New("dbus config not supplied")
-)
+// ErrDBusConfig is returned when a required [hst.BusConfig] argument is nil.
+var ErrDBusConfig = errors.New("dbus config not supplied")
 
 // MustProxyDBus calls ProxyDBus and panics if an error is returned.
-func (sys *I) MustProxyDBus(sessionPath *check.Absolute, session *hst.BusConfig, systemPath *check.Absolute, system *hst.BusConfig) *I {
-	if err := sys.ProxyDBus(session, system, sessionPath, systemPath); err != nil {
+func (sys *I) MustProxyDBus(
+	session, system *hst.BusConfig,
+	sessionBus, systemBus dbus.ProxyPair,
+) *I {
+	if err := sys.ProxyDBus(session, system, sessionBus, systemBus); err != nil {
 		panic(err.Error())
 	} else {
 		return sys
@@ -32,7 +33,10 @@ func (sys *I) MustProxyDBus(sessionPath *check.Absolute, session *hst.BusConfig,
 
 // ProxyDBus finalises configuration ahead of time and starts xdg-dbus-proxy via [dbus] and terminates it on revert.
 // This [Op] is always [Process] scoped.
-func (sys *I) ProxyDBus(session, system *hst.BusConfig, sessionPath, systemPath *check.Absolute) error {
+func (sys *I) ProxyDBus(
+	session, system *hst.BusConfig,
+	sessionBus, systemBus dbus.ProxyPair,
+) error {
 	d := new(dbusProxyOp)
 
 	// session bus is required as otherwise this is effectively a very expensive noop
@@ -44,9 +48,6 @@ func (sys *I) ProxyDBus(session, system *hst.BusConfig, sessionPath, systemPath
 	// system bus is optional
 	d.system = system != nil
 
-	var sessionBus, systemBus dbus.ProxyPair
-	sessionBus[0], systemBus[0] = sys.dbusAddress()
-	sessionBus[1], systemBus[1] = sessionPath.String(), systemPath.String()
 	d.out = &linePrefixWriter{println: log.Println, prefix: "(dbus) ", buf: new(strings.Builder)}
 	if final, err := sys.dbusFinalise(sessionBus, systemBus, session, system); err != nil {
 		if errors.Is(err, syscall.EINVAL) {

system/dbus/dbus.go

@@ -8,27 +8,31 @@ import (
 )
 
 const (
-	/*SessionBusAddress is the name of the environment variable where the address of the login session message bus is given in.
+	/*
+		SessionBusAddress is the name of the environment variable where the address of the login session message bus is given in.
 
-	If that variable is not set, applications may also try to read the address from the X Window System root window property _DBUS_SESSION_BUS_ADDRESS.
-	The root window property must have type STRING. The environment variable should have precedence over the root window property.
+		If that variable is not set, applications may also try to read the address from the X Window System root window property _DBUS_SESSION_BUS_ADDRESS.
+		The root window property must have type STRING. The environment variable should have precedence over the root window property.
 
-	The address of the login session message bus is given in the DBUS_SESSION_BUS_ADDRESS environment variable.
-	If DBUS_SESSION_BUS_ADDRESS is not set, or if it's set to the string "autolaunch:",
-	the system should use platform-specific methods of locating a running D-Bus session server,
-	or starting one if a running instance cannot be found.
-	Note that this mechanism is not recommended for attempting to determine if a daemon is running.
-	It is inherently racy to attempt to make this determination, since the bus daemon may be started just before or just after the determination is made.
-	Therefore, it is recommended that applications do not try to make this determination for their functionality purposes, and instead they should attempt to start the server.
+		The address of the login session message bus is given in the DBUS_SESSION_BUS_ADDRESS environment variable.
+		If DBUS_SESSION_BUS_ADDRESS is not set, or if it's set to the string "autolaunch:",
+		the system should use platform-specific methods of locating a running D-Bus session server,
+		or starting one if a running instance cannot be found.
+		Note that this mechanism is not recommended for attempting to determine if a daemon is running.
+		It is inherently racy to attempt to make this determination, since the bus daemon may be started just before or just after the determination is made.
+		Therefore, it is recommended that applications do not try to make this determination for their functionality purposes, and instead they should attempt to start the server.
 
-	This package diverges from the specification, as the caller is unlikely to be an X client, or be in a position to autolaunch a dbus server.
-	So a fallback address with a socket located in the well-known default XDG_RUNTIME_DIR formatting is used.*/
+		This package diverges from the specification, as the caller is unlikely to be an X client, or be in a position to autolaunch a dbus server.
+		So a fallback address with a socket located in the well-known default XDG_RUNTIME_DIR formatting is used.
+	*/
 	SessionBusAddress = "DBUS_SESSION_BUS_ADDRESS"
 
-	/*SystemBusAddress is the name of the environment variable where the address of the system message bus is given in.
+	/*
+		SystemBusAddress is the name of the environment variable where the address of the system message bus is given in.
 
-	If that variable is not set, applications should try to connect to the well-known address unix:path=/var/run/dbus/system_bus_socket.
-	Implementations of the well-known system bus should listen on an address that will result in that connection being successful.*/
+		If that variable is not set, applications should try to connect to the well-known address unix:path=/var/run/dbus/system_bus_socket.
+		Implementations of the well-known system bus should listen on an address that will result in that connection being successful.
+	*/
 	SystemBusAddress = "DBUS_SYSTEM_BUS_ADDRESS"
 
 	// FallbackSystemBusAddress is used when [SystemBusAddress] is not set.
@@ -36,28 +40,30 @@ const (
 )
 
 var (
-	addresses   [2]string
+	address     [2]string
 	addressOnce sync.Once
 )
 
+// Address returns the session and system bus addresses copied from environment,
+// or appropriate fallback values if they are not set.
 func Address() (session, system string) {
 	addressOnce.Do(func() {
 		// resolve upstream session bus address
 		if addr, ok := os.LookupEnv(SessionBusAddress); !ok {
 			// fall back to default format
-			addresses[0] = fmt.Sprintf("unix:path=/run/user/%d/bus", os.Getuid())
+			address[0] = fmt.Sprintf("unix:path=/run/user/%d/bus", os.Getuid())
 		} else {
-			addresses[0] = addr
+			address[0] = addr
 		}
 
 		// resolve upstream system bus address
 		if addr, ok := os.LookupEnv(SystemBusAddress); !ok {
 			// fall back to default hardcoded value
-			addresses[1] = FallbackSystemBusAddress
+			address[1] = FallbackSystemBusAddress
 		} else {
-			addresses[1] = addr
+			address[1] = addr
 		}
 	})
 
-	return addresses[0], addresses[1]
+	return address[0], address[1]
 }

system/dbus_test.go

@@ -85,7 +85,7 @@ func TestDBusProxyOp(t *testing.T) {
 				Op: "dbus", Err: ErrDBusConfig,
 				Msg: "attempted to create message bus proxy args without session bus config",
 			}
-			if err := sys.ProxyDBus(nil, new(hst.BusConfig), nil, nil); !reflect.DeepEqual(err, wantErr) {
+			if err := sys.ProxyDBus(nil, new(hst.BusConfig), dbus.ProxyPair{}, dbus.ProxyPair{}); !reflect.DeepEqual(err, wantErr) {
 				t.Errorf("ProxyDBus: error = %v, want %v", err, wantErr)
 			}
 		}, nil, stub.Expect{}},
@@ -99,15 +99,20 @@ func TestDBusProxyOp(t *testing.T) {
 			}()
 
 			sys.MustProxyDBus(
-				m("/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus"), &hst.BusConfig{
+				&hst.BusConfig{
 					// use impossible value here as an implicit assert that it goes through the stub
 					Talk: []string{"session\x00"}, Filter: true,
-				}, m("/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket"), &hst.BusConfig{
+				}, &hst.BusConfig{
 					// use impossible value here as an implicit assert that it goes through the stub
 					Talk: []string{"system\x00"}, Filter: true,
+				}, dbus.ProxyPair{
+					"unix:path=/run/user/1000/bus",
+					"/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus",
+				}, dbus.ProxyPair{
+					"unix:path=/run/dbus/system_bus_socket",
+					"/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket",
 				})
 		}, nil, stub.Expect{Calls: []stub.Call{
-			call("dbusAddress", stub.ExpectArgs{}, [2]string{"unix:path=/run/user/1000/bus", "unix:path=/run/dbus/system_bus_socket"}, nil),
 			call("dbusFinalise", stub.ExpectArgs{
 				dbus.ProxyPair{"unix:path=/run/user/1000/bus", "/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus"},
 				dbus.ProxyPair{"unix:path=/run/dbus/system_bus_socket", "/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket"},
@@ -128,13 +133,16 @@ func TestDBusProxyOp(t *testing.T) {
 				}, &hst.BusConfig{
 					// use impossible value here as an implicit assert that it goes through the stub
 					Talk: []string{"system\x00"}, Filter: true,
-				},
-				m("/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus"),
-				m("/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket")); !reflect.DeepEqual(err, wantErr) {
+				}, dbus.ProxyPair{
+					"unix:path=/run/user/1000/bus",
+					"/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus",
+				}, dbus.ProxyPair{
+					"unix:path=/run/dbus/system_bus_socket",
+					"/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket",
+				}); !reflect.DeepEqual(err, wantErr) {
 				t.Errorf("ProxyDBus: error = %v", err)
 			}
 		}, nil, stub.Expect{Calls: []stub.Call{
-			call("dbusAddress", stub.ExpectArgs{}, [2]string{"unix:path=/run/user/1000/bus", "unix:path=/run/dbus/system_bus_socket"}, nil),
 			call("dbusFinalise", stub.ExpectArgs{
 				dbus.ProxyPair{"unix:path=/run/user/1000/bus", "/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus"},
 				dbus.ProxyPair{"unix:path=/run/dbus/system_bus_socket", "/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket"},
@@ -145,12 +153,18 @@ func TestDBusProxyOp(t *testing.T) {
 
 		{"full", 0xcafebabe, func(_ *testing.T, sys *I) {
 			sys.MustProxyDBus(
-				m("/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus"), &hst.BusConfig{
+				&hst.BusConfig{
 					// use impossible value here as an implicit assert that it goes through the stub
 					Talk: []string{"session\x00"}, Filter: true,
-				}, m("/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket"), &hst.BusConfig{
+				}, &hst.BusConfig{
 					// use impossible value here as an implicit assert that it goes through the stub
 					Talk: []string{"system\x00"}, Filter: true,
+				}, dbus.ProxyPair{
+					"unix:path=/run/user/1000/bus",
+					"/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus",
+				}, dbus.ProxyPair{
+					"unix:path=/run/dbus/system_bus_socket",
+					"/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket",
 				})
 		}, []Op{
 			&dbusProxyOp{
@@ -158,7 +172,6 @@ func TestDBusProxyOp(t *testing.T) {
 				system: true,
 			},
 		}, stub.Expect{Calls: []stub.Call{
-			call("dbusAddress", stub.ExpectArgs{}, [2]string{"unix:path=/run/user/1000/bus", "unix:path=/run/dbus/system_bus_socket"}, nil),
 			call("dbusFinalise", stub.ExpectArgs{
 				dbus.ProxyPair{"unix:path=/run/user/1000/bus", "/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/bus"},
 				dbus.ProxyPair{"unix:path=/run/dbus/system_bus_socket", "/tmp/hakurei.0/99dd71ee2146369514e0d10783368f8f/system_bus_socket"},

system/dispatcher.go

@@ -48,8 +48,6 @@ type syscallDispatcher interface {
 	// xcbChangeHosts provides [xcb.ChangeHosts].
 	xcbChangeHosts(mode xcb.HostMode, family xcb.Family, address string) error
 
-	// dbusAddress provides [dbus.Address].
-	dbusAddress() (session, system string)
 	// dbusFinalise provides [dbus.Finalise].
 	dbusFinalise(sessionBus, systemBus dbus.ProxyPair, session, system *hst.BusConfig) (final *dbus.Final, err error)
 	// dbusProxyStart provides the Start method of [dbus.Proxy].
@@ -82,10 +80,6 @@ func (k direct) xcbChangeHosts(mode xcb.HostMode, family xcb.Family, address str
 	return xcb.ChangeHosts(mode, family, address)
 }
 
-func (k direct) dbusAddress() (session, system string) {
-	return dbus.Address()
-}
-
 func (k direct) dbusFinalise(sessionBus, systemBus dbus.ProxyPair, session, system *hst.BusConfig) (final *dbus.Final, err error) {
 	return dbus.Finalise(sessionBus, systemBus, session, system)
 }

system/dispatcher_test.go

@@ -276,12 +276,6 @@ func (k *kstub) xcbChangeHosts(mode xcb.HostMode, family xcb.Family, address str
 		stub.CheckArg(k.Stub, "address", address, 2))
 }
 
-func (k *kstub) dbusAddress() (session, system string) {
-	k.Helper()
-	ret := k.Expects("dbusAddress").Ret.([2]string)
-	return ret[0], ret[1]
-}
-
 func (k *kstub) dbusFinalise(sessionBus, systemBus dbus.ProxyPair, session, system *hst.BusConfig) (final *dbus.Final, err error) {
 	k.Helper()
 	expect := k.Expects("dbusFinalise")