webdav: add COPY support to server

carddav/server.go

@@ -277,6 +277,10 @@ func (b *backend) Mkcol(r *http.Request) error {
 	return internal.HTTPErrorf(http.StatusForbidden, "carddav: address book creation unsupported")
 }
 
+func (b *backend) Copy(r *http.Request, dest *internal.Href, recursive, overwrite bool) (created bool, err error) {
+	panic("TODO")
+}
+
 func (b *backend) Move(r *http.Request, dest *internal.Href, overwrite bool) (created bool, err error) {
 	panic("TODO")
 }

fs_local.go

@@ -21,7 +21,7 @@ func (fs LocalFileSystem) localPath(name string) (string, error) {
 	}
 	name = path.Clean(name)
 	if !path.IsAbs(name) {
-		return "", internal.HTTPErrorf(http.StatusBadRequest, "webdav: expected absolute path")
+		return "", internal.HTTPErrorf(http.StatusBadRequest, "webdav: expected absolute path, got %q", name)
 	}
 	return filepath.Join(string(fs), filepath.FromSlash(name)), nil
 }
@@ -129,6 +129,87 @@ func (fs LocalFileSystem) Mkdir(name string) error {
 	return os.Mkdir(p, 0755)
 }
 
+func copyRegularFile(src, dst string, perm os.FileMode) error {
+	srcFile, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer srcFile.Close()
+
+	dstFile, err := os.OpenFile(dst, os.O_RDWR|os.O_CREATE|os.O_TRUNC, perm)
+	if err != nil {
+		// TODO: send http.StatusConflict on os.IsNotExist
+		return err
+	}
+	defer dstFile.Close()
+
+	if _, err := io.Copy(dstFile, srcFile); err != nil {
+		return err
+	}
+
+	return dstFile.Close()
+}
+
+func (fs LocalFileSystem) Copy(src, dst string, recursive, overwrite bool) (created bool, err error) {
+	srcPath, err := fs.localPath(src)
+	if err != nil {
+		return false, err
+	}
+	dstPath, err := fs.localPath(dst)
+	if err != nil {
+		return false, err
+	}
+
+	// TODO: "Note that an infinite-depth COPY of /A/ into /A/B/ could lead to
+	// infinite recursion if not handled correctly"
+
+	srcInfo, err := os.Stat(srcPath)
+	if err != nil {
+		return false, err
+	}
+	srcPerm := srcInfo.Mode() & os.ModePerm
+
+	if _, err := os.Stat(dstPath); err != nil {
+		if !os.IsNotExist(err) {
+			return false, err
+		}
+		created = true
+	} else {
+		if !overwrite {
+			return false, os.ErrExist
+		}
+		if err := os.RemoveAll(dstPath); err != nil {
+			return false, err
+		}
+	}
+
+	err = filepath.Walk(srcPath, func(p string, fi os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if fi.IsDir() {
+			if err := os.Mkdir(dstPath, srcPerm); err != nil {
+				return err
+			}
+		} else {
+			if err := copyRegularFile(srcPath, dstPath, srcPerm); err != nil {
+				return err
+			}
+		}
+
+		if fi.IsDir() && !recursive {
+			return filepath.SkipDir
+		}
+		return nil
+	})
+	if err != nil {
+		return false, err
+	}
+
+	return created, nil
+}
+
 func (fs LocalFileSystem) MoveAll(src, dst string, overwrite bool) (created bool, err error) {
 	srcPath, err := fs.localPath(src)
 	if err != nil {
@@ -145,13 +226,12 @@ func (fs LocalFileSystem) MoveAll(src, dst string, overwrite bool) (created bool
 		}
 		created = true
 	} else {
-		if overwrite {
+		if !overwrite {
+			return false, os.ErrExist
+		}
 		if err := os.RemoveAll(dstPath); err != nil {
 			return false, err
 		}
-		} else {
-			return false, os.ErrExist
-		}
 	}
 
 	if err := os.Rename(srcPath, dstPath); err != nil {

internal/server.go

@@ -82,6 +82,7 @@ type Backend interface {
 	Put(r *http.Request) error
 	Delete(r *http.Request) error
 	Mkcol(r *http.Request) error
+	Copy(r *http.Request, dest *Href, recursive, overwrite bool) (created bool, err error)
 	Move(r *http.Request, dest *Href, overwrite bool) (created bool, err error)
 }
 
@@ -122,8 +123,8 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			if err == nil {
 				w.WriteHeader(http.StatusCreated)
 			}
-		case "MOVE":
-			err = h.handleMove(w, r)
+		case "COPY", "MOVE":
+			err = h.handleCopyMove(w, r)
 		default:
 			err = HTTPErrorf(http.StatusMethodNotAllowed, "webdav: unsupported method")
 		}
@@ -271,7 +272,7 @@ func parseDestination(h http.Header) (*Href, error) {
 	return (*Href)(dest), nil
 }
 
-func (h *Handler) handleMove(w http.ResponseWriter, r *http.Request) error {
+func (h *Handler) handleCopyMove(w http.ResponseWriter, r *http.Request) error {
 	dest, err := parseDestination(r.Header)
 	if err != nil {
 		return err
@@ -285,10 +286,37 @@ func (h *Handler) handleMove(w http.ResponseWriter, r *http.Request) error {
 		}
 	}
 
-	created, err := h.Backend.Move(r, dest, overwrite)
+	depth := DepthInfinity
+	if s := r.Header.Get("Depth"); s != "" {
+		depth, err = ParseDepth(s)
 		if err != nil {
 			return err
 		}
+	}
+
+	var created bool
+	if r.Method == "COPY" {
+		var recursive bool
+		switch depth {
+		case DepthZero:
+			recursive = false
+		case DepthOne:
+			return HTTPErrorf(http.StatusBadRequest, `webdav: "Depth: 1" is not supported in COPY request`)
+		case DepthInfinity:
+			recursive = true
+		}
+
+		created, err = h.Backend.Copy(r, dest, recursive, overwrite)
+	} else {
+		if depth != DepthInfinity {
+			return HTTPErrorf(http.StatusBadRequest, `webdav: only "Depth: infinity" is accepted in MOVE request`)
+		}
+		created, err = h.Backend.Move(r, dest, overwrite)
+	}
+	if err != nil {
+		return err
+	}
+
 	if created {
 		w.WriteHeader(http.StatusCreated)
 	} else {

server.go

@@ -19,6 +19,7 @@ type FileSystem interface {
 	Create(name string) (io.WriteCloser, error)
 	RemoveAll(name string) error
 	Mkdir(name string) error
+	Copy(name, dest string, recursive, overwrite bool) (created bool, err error)
 	MoveAll(name, dest string, overwrite bool) (created bool, err error)
 }
 
@@ -223,6 +224,14 @@ func (b *backend) Mkcol(r *http.Request) error {
 	return err
 }
 
+func (b *backend) Copy(r *http.Request, dest *internal.Href, recursive, overwrite bool) (created bool, err error) {
+	created, err = b.FileSystem.Copy(r.URL.Path, dest.Path, recursive, overwrite)
+	if os.IsExist(err) {
+		return false, &internal.HTTPError{http.StatusPreconditionFailed, err}
+	}
+	return created, err
+}
+
 func (b *backend) Move(r *http.Request, dest *internal.Href, overwrite bool) (created bool, err error) {
 	created, err = b.FileSystem.MoveAll(r.URL.Path, dest.Path, overwrite)
 	if os.IsExist(err) {