dbus: use name resolved by exec.Command

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

dbus/dbus.go

@@ -9,12 +9,16 @@ import (
 	"git.ophivana.moe/cat/fortify/helper"
 )
 
+// ProxyName is the file name or path to the proxy program.
+// Overriding ProxyName will only affect Proxy instance created after the change.
+var ProxyName = "xdg-dbus-proxy"
+
 // Proxy holds references to a xdg-dbus-proxy process, and should never be copied.
 // Once sealed, configuration changes will no longer be possible and attempting to do so will result in a panic.
 type Proxy struct {
 	helper helper.Helper
 
-	path    string
+	name    string
 	session [2]string
 	system  [2]string
 
@@ -75,6 +79,6 @@ func (p *Proxy) Seal(session, system *Config) error {
 }
 
 // New returns a reference to a new unsealed Proxy.
-func New(binPath string, session, system [2]string) *Proxy {
-	return &Proxy{path: binPath, session: session, system: system}
+func New(session, system [2]string) *Proxy {
+	return &Proxy{name: ProxyName, session: session, system: system}
 }

dbus/dbus_test.go

@@ -9,10 +9,6 @@ import (
 	"git.ophivana.moe/cat/fortify/helper"
 )
 
-const (
-	binPath = "/usr/bin/bwrap"
-)
-
 func TestNew(t *testing.T) {
 	for _, tc := range [][2][2]string{
 		{
@@ -33,9 +29,9 @@ func TestNew(t *testing.T) {
 		},
 	} {
 		t.Run("create instance for "+tc[0][0]+" and "+tc[1][0], func(t *testing.T) {
-			if got := dbus.New(binPath, tc[0], tc[1]); !got.CompareTestNew(binPath, tc[0], tc[1]) {
-				t.Errorf("New(%q, %q, %q) = %v",
-					binPath, tc[0], tc[1],
+			if got := dbus.New(tc[0], tc[1]); !got.CompareTestNew(tc[0], tc[1]) {
+				t.Errorf("New(%q, %q) = %v",
+					tc[0], tc[1],
 					got)
 			}
 		})
@@ -52,12 +48,12 @@ func TestProxy_Seal(t *testing.T) {
 			}
 		}()
 
-		p := dbus.New(binPath, [2]string{}, [2]string{})
+		p := dbus.New([2]string{}, [2]string{})
 		_ = p.Seal(dbus.NewConfig("", true, false), nil)
 		_ = p.Seal(dbus.NewConfig("", true, false), nil)
 	})
 
-	ep := dbus.New(binPath, [2]string{}, [2]string{})
+	ep := dbus.New([2]string{}, [2]string{})
 	if err := ep.Seal(nil, nil); !errors.Is(err, dbus.ErrConfig) {
 		t.Errorf("Seal(nil, nil) error = %v, want %v",
 			err, dbus.ErrConfig)
@@ -65,7 +61,7 @@ func TestProxy_Seal(t *testing.T) {
 
 	for id, tc := range testCasePairs() {
 		t.Run("create seal for "+id, func(t *testing.T) {
-			p := dbus.New(binPath, tc[0].bus, tc[1].bus)
+			p := dbus.New(tc[0].bus, tc[1].bus)
 			if err := p.Seal(tc[0].c, tc[1].c); (errors.Is(err, helper.ErrContainsNull)) != tc[0].wantErr {
 				t.Errorf("Seal(%p, %p) error = %v, wantErr %v",
 					tc[0].c, tc[1].c,
@@ -119,7 +115,7 @@ func TestProxy_Start_Wait_Close_String(t *testing.T) {
 
 		t.Run("proxy for "+id, func(t *testing.T) {
 			helper.InternalReplaceExecCommand(t)
-			p := dbus.New(binPath, tc[0].bus, tc[1].bus)
+			p := dbus.New(tc[0].bus, tc[1].bus)
 
 			t.Run("unsealed behaviour of "+id, func(t *testing.T) {
 				t.Run("unsealed string of "+id, func(t *testing.T) {
@@ -164,7 +160,7 @@ func TestProxy_Start_Wait_Close_String(t *testing.T) {
 					}
 
 					t.Run("started string of "+id, func(t *testing.T) {
-						wantSubstr := binPath + " --args=3"
+						wantSubstr := dbus.ProxyName + " --args=3"
 						if got := p.String(); !strings.Contains(got, wantSubstr) {
 							t.Errorf("String() = %v, want %v",
 								p.String(), wantSubstr)

dbus/export_test.go

@@ -3,8 +3,8 @@ package dbus
 import "io"
 
 // CompareTestNew provides TestNew with comparison access to unexported Proxy fields.
-func (p *Proxy) CompareTestNew(path string, session, system [2]string) bool {
-	return path == p.path && session == p.session && system == p.system
+func (p *Proxy) CompareTestNew(session, system [2]string) bool {
+	return session == p.session && system == p.system
 }
 
 // AccessTestProxySeal provides TestProxy_Seal with access to unexported Proxy seal field.

dbus/run.go

@@ -18,7 +18,7 @@ func (p *Proxy) Start(ready chan error, output io.Writer) error {
 		return errors.New("proxy not sealed")
 	}
 
-	h := helper.New(p.seal, p.path,
+	h := helper.New(p.seal, p.name,
 		func(argsFD, statFD int) []string {
 			if statFD == -1 {
 				return []string{"--args=" + strconv.Itoa(argsFD)}

internal/app/share.dbus.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"path"
 
 	"git.ophivana.moe/cat/fortify/acl"
@@ -16,13 +15,10 @@ import (
 const (
 	dbusSessionBusAddress = "DBUS_SESSION_BUS_ADDRESS"
 	dbusSystemBusAddress  = "DBUS_SYSTEM_BUS_ADDRESS"
-
-	xdgDBusProxy = "xdg-dbus-proxy"
 )
 
 var (
 	ErrDBusConfig = errors.New("dbus config not supplied")
-	ErrDBusProxy  = errors.New(xdgDBusProxy + " not found")
 )
 
 type (
@@ -68,13 +64,8 @@ func (seal *appSeal) shareDBus(config [2]*dbus.Config) error {
 		systemBus[0] = addr
 	}
 
-	// look up proxy program path for dbus.New
-	if b, err := exec.LookPath(xdgDBusProxy); err != nil {
-		return (*LookupDBusError)(wrapError(ErrDBusProxy, xdgDBusProxy, "not found"))
-	} else {
-		// create proxy instance
-		seal.sys.dbus = dbus.New(b, sessionBus, systemBus)
-	}
+	// create proxy instance
+	seal.sys.dbus = dbus.New(sessionBus, systemBus)
 
 	// seal dbus proxy
 	if err := seal.sys.dbus.Seal(config[0], config[1]); err != nil {