internal/pipewire: integrate pw_security_context

This is required for securely providing access to PipeWire.

This change has already been manually tested and confirmed to work correctly.

This unfortunately cannot be upstreamed in its current state as libpipewire-0.3 breaks static linking.

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

internal/pipewire/conn_test.go

@@ -0,0 +1,66 @@
+package pipewire
+
+import (
+	"errors"
+	"os"
+	"path"
+	"reflect"
+	"syscall"
+	"testing"
+
+	"hakurei.app/container/check"
+)
+
+func TestSecurityContextClose(t *testing.T) {
+	// do not parallel: fd test not thread safe
+
+	if err := (*SecurityContext)(nil).Close(); !reflect.DeepEqual(err, os.ErrInvalid) {
+		t.Fatalf("Close: error = %v", err)
+	}
+
+	var ctx SecurityContext
+	if err := syscall.Pipe2(ctx.closeFds[0:], syscall.O_CLOEXEC); err != nil {
+		t.Fatalf("Pipe: error = %v", err)
+	}
+	if f, err := os.Create(path.Join(t.TempDir(), "remove")); err != nil {
+		t.Fatal(err)
+	} else {
+		ctx.bindPath = check.MustAbs(f.Name())
+	}
+	t.Cleanup(func() { _ = syscall.Close(ctx.closeFds[0]); _ = syscall.Close(ctx.closeFds[1]) })
+
+	if err := ctx.Close(); err != nil {
+		t.Fatalf("Close: error = %v", err)
+	} else if _, err = os.Stat(ctx.bindPath.String()); err == nil || !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("Did not remove %q", ctx.bindPath)
+	}
+
+	wantErr := &Error{Cause: RCleanup, Path: ctx.bindPath.String(), Errno: errors.Join(syscall.EBADF, syscall.EBADF, &os.PathError{
+		Op:   "remove",
+		Path: ctx.bindPath.String(),
+		Err:  syscall.ENOENT,
+	})}
+	if err := ctx.Close(); !reflect.DeepEqual(err, wantErr) {
+		t.Fatalf("Close: error = %#v, want %#v", err, wantErr)
+	}
+}
+
+func TestNewEnsure(t *testing.T) {
+	existingDirPath := check.MustAbs(t.TempDir()).Append("dir")
+	if err := os.MkdirAll(existingDirPath.String(), 0700); err != nil {
+		t.Fatal(err)
+	}
+	nonexistent := check.MustAbs("/proc/nonexistent")
+
+	wantErr := &Error{RCreate, existingDirPath.String(), &os.PathError{
+		Op:   "open",
+		Path: existingDirPath.String(),
+		Err:  syscall.EISDIR,
+	}}
+	if _, err := New(
+		nonexistent,
+		existingDirPath,
+	); !reflect.DeepEqual(err, wantErr) {
+		t.Fatalf("New: error = %#v, want %#v", err, wantErr)
+	}
+}