1 files changed, 59 insertions, 0 deletions
diff --git a/internal/syscallcompat/asuser.go b/internal/syscallcompat/asuser.go
new file mode 100644
index 0000000..0c083ec
--- /dev/null
+++ b/internal/syscallcompat/asuser.go
@@ -0,0 +1,59 @@
+package syscallcompat
+
+import (
+	"golang.org/x/sys/unix"
+
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+// OpenatUser runs the Openat syscall in the context of a different user.
+// It switches the current thread to the new user, performs the syscall,
+// and switches back.
+//
+// If `context` is nil, this function behaves like ordinary Openat (no
+// user switching).
+func OpenatUser(dirfd int, path string, flags int, mode uint32, context *fuse.Context) (fd int, err error) {
+	f := func() (int, error) {
+		return Openat(dirfd, path, flags, mode)
+	}
+	return asUser(f, context)
+}
+
+// MknodatUser runs the Mknodat syscall in the context of a different user.
+// If `context` is nil, this function behaves like ordinary Mknodat.
+//
+// See OpenatUser() for how this works.
+func MknodatUser(dirfd int, path string, mode uint32, dev int, context *fuse.Context) (err error) {
+	f := func() (int, error) {
+		err := Mknodat(dirfd, path, mode, dev)
+		return -1, err
+	}
+	_, err = asUser(f, context)
+	return err
+}
+
+// SymlinkatUser runs the Symlinkat syscall in the context of a different user.
+// If `context` is nil, this function behaves like ordinary Symlinkat.
+//
+// See OpenatUser() for how this works.
+func SymlinkatUser(oldpath string, newdirfd int, newpath string, context *fuse.Context) (err error) {
+	f := func() (int, error) {
+		err := unix.Symlinkat(oldpath, newdirfd, newpath)
+		return -1, err
+	}
+	_, err = asUser(f, context)
+	return err
+}
+
+// MkdiratUser runs the Mkdirat syscall in the context of a different user.
+// If `context` is nil, this function behaves like ordinary Mkdirat.
+//
+// See OpenatUser() for how this works.
+func MkdiratUser(dirfd int, path string, mode uint32, context *fuse.Context) (err error) {
+	f := func() (int, error) {
+		err := unix.Mkdirat(dirfd, path, mode)
+		return -1, err
+	}
+	_, err = asUser(f, context)
+	return err
+}