added range support to continue interrupted download

2026-11-06 20:57:37 +01:00
parent 2098082aa6
commit 0bfa5ed35c
6 changed files with 187 additions and 14 deletions
@@ -0,0 +1,166 @@
+package server
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"serveg/internal/http"
+	"strconv"
+)
+
+func DirOrFileExists(path string) (exists bool, fi os.FileInfo, err error) {
+	fi, err = os.Stat(path)
+	if errors.Is(err, os.ErrNotExist) {
+		err = nil
+	} else if err == nil {
+		exists = true
+	}
+	return
+}
+
+var ErrIsUploadingAlready = http.NewHttpError(http.StatusConflict,
+	"somebody is already uploading such file")
+var ErrFileIsDir = http.NewHttpError(http.StatusConflict,
+	"there is a directory with such name already")
+
+// PUT: accept request body and write it to filePath+".uploading"
+// OPTIONS: check if file can be uploaded and return without reading body
+// returns StatusCreated if upload is a new file, and StatusOK if it is replacing existing file
+func (conn *TcpConnection) PUT_OPTIONS(req *http.Request) *http.Response {
+	reqHasBody := req.Method == "PUT"
+	path, share, urlStatus := conn.srv.Conf.Share.MapUrl(req.Url)
+	// handle authorization
+	if share != nil {
+		if share.WritePassword == "" {
+			return conn.createErrorResponse(req, reqHasBody, http.StatusForbidden, "share is read-only")
+		}
+		access := checkSharePasswords(share, req)
+		if access < AccessReadWrite {
+			return conn.createErrorResponse(req, reqHasBody,
+				http.StatusUnauthorized, "writer password required").
+				WithHeader("www-authenticate",
+					`Basic realm="`+share.Url+` (write)", charset="UTF-8"`)
+		}
+	}
+
+	switch urlStatus {
+	case UrlFile:
+		return conn.handleUpload(req, path, true)
+	case UrlDir:
+		return conn.http.CreateErrorResponse(req, reqHasBody, ErrFileIsDir)
+	case UrlDoesntExistInShare:
+		// TODO: allow users to create directories
+		return conn.handleUpload(req, path, false)
+	case UrlShareNotFound:
+		return conn.createErrorResponse(req, reqHasBody, http.StatusNotFound, req.Url)
+	case UrlForbidden:
+		return conn.createErrorResponse(req, reqHasBody, http.StatusForbidden, req.Url)
+	case UrlIncorrect:
+		return conn.createErrorResponse(req, reqHasBody, http.StatusBadRequest,
+			"invalid url '"+req.Url+"'")
+	default:
+		panic(fmt.Sprintf("unsupported UrlStatus: %d", int32(urlStatus)))
+	}
+}
+
+func (conn *TcpConnection) handleUpload(req *http.Request, filePath string, fileExists bool,
+) *http.Response {
+	reqHasBody := req.Method == "PUT"
+	maxUpload := conn.srv.Conf.MaxUpload
+	var resultStatus http.StatusCode
+	if fileExists {
+		resultStatus = http.StatusOK
+	} else {
+		resultStatus = http.StatusCreated
+	}
+
+	errToResponse := func(err error) *http.Response {
+		httpErr, ok := errors.AsType[*http.HttpError](err)
+		if !ok {
+			httpErr = http.NewHttpError(http.StatusInternalServerError, err.Error())
+		}
+		return conn.http.CreateErrorResponse(req, reqHasBody, httpErr)
+	}
+	createResponseMsg := func(status http.StatusCode, msg string) *http.Response {
+		return conn.http.CreateResponse(status, req, false).
+			WithBodyStr(msg, http.TextPlain)
+	}
+
+	tmpPath := filePath + ".uploading"
+	tmpFileExists, fi, err := DirOrFileExists(tmpPath)
+	if err != nil {
+		return errToResponse(err)
+	}
+	if tmpFileExists {
+		var httpErr *http.HttpError
+		if fi.IsDir() {
+			httpErr = ErrFileIsDir
+		} else {
+			httpErr = ErrIsUploadingAlready
+		}
+		return conn.http.CreateErrorResponse(req, reqHasBody, httpErr)
+	}
+
+	// OPTIONS
+	if !reqHasBody {
+		uploadSize, err := strconv.ParseUint(req.Headers["x-upload-size"], 10, 63)
+		if err != nil {
+			return createResponseMsg(http.StatusBadRequest,
+				"OPTIONS request must have valid header x-upload-size")
+		}
+		if uploadSize > maxUpload {
+			return createResponseMsg(http.StatusRequestEntityTooLarge,
+				fmt.Sprintf("x-upload-size (%v) > maxUpload (%v)",
+					uploadSize, maxUpload))
+		}
+		return conn.http.CreateResponse(resultStatus, req, false)
+	}
+
+	// PUT
+	f, err := os.OpenFile(tmpPath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0o644)
+	if errors.Is(err, os.ErrExist) {
+		return errToResponse(ErrIsUploadingAlready)
+	}
+	if err != nil {
+		return errToResponse(err)
+	}
+	renamed := false
+	defer func() {
+		_ = f.Close()
+		// remove temp file if upload failed
+		if !renamed {
+			// TODO: log this error
+			_ = os.Remove(tmpPath)
+		}
+	}()
+
+	// read request body
+	reqBody, err := req.GetBodyReader(int64(maxUpload))
+	if err != nil {
+		return errToResponse(err)
+	}
+	n, err := io.Copy(f, reqBody)
+	if err != nil {
+		return errToResponse(err)
+	}
+	if n != req.ContentLength {
+		return conn.createErrorResponse(req, true, http.StatusBadRequest,
+			"uploaded file size != content-length")
+	}
+
+	// move tmpPath to filePath
+	if err = f.Sync(); err != nil {
+		return errToResponse(err)
+	}
+	if err = f.Close(); err != nil {
+		return errToResponse(err)
+	}
+	if err = os.Rename(tmpPath, filePath); err != nil {
+		return errToResponse(err)
+	}
+	renamed = true
+
+	// TODO: is it right status?
+	return conn.http.CreateResponse(resultStatus, req, false)
+}