internal/wayland: check pathname size

This avoids passing a truncated pathname to the kernel.

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

internal/wayland/conn_test.go

@@ -0,0 +1,54 @@
+package wayland
+
+import (
+	"errors"
+	"os"
+	"reflect"
+	"syscall"
+	"testing"
+
+	"hakurei.app/container/check"
+)
+
+func TestSecurityContextClose(t *testing.T) {
+	t.Parallel()
+
+	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)
+	}
+	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)
+	}
+
+	wantErr := errors.Join(syscall.EBADF, syscall.EBADF)
+	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(), nonexistent.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)
+	}
+}