https://github.com/matrix-org/dendrite fork for cross-compile for ARM
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// Copyright 2017 Vector Creations Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package routing
import (
"context"
"crypto/rand"
"encoding/hex"
"fmt"
"io"
"net/http"
"net/url"
"path"
"strings"
"github.com/matrix-org/dendrite/clientapi/jsonerror"
"github.com/matrix-org/dendrite/mediaapi/fileutils"
"github.com/matrix-org/dendrite/mediaapi/storage"
"github.com/matrix-org/dendrite/mediaapi/thumbnailer"
"github.com/matrix-org/dendrite/mediaapi/types"
"github.com/matrix-org/dendrite/setup/config"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/gomatrixserverlib"
"github.com/matrix-org/util"
log "github.com/sirupsen/logrus"
)
// uploadRequest metadata included in or derivable from an upload request
// https://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-media-r0-upload
// NOTE: The members come from HTTP request metadata such as headers, query parameters or can be derived from such
type uploadRequest struct {
MediaMetadata *types.MediaMetadata
Logger *log.Entry
}
// uploadResponse defines the format of the JSON response
// https://matrix.org/docs/spec/client_server/r0.2.0.html#post-matrix-media-r0-upload
type uploadResponse struct {
ContentURI string `json:"content_uri"`
}
// Upload implements POST /upload
// This endpoint involves uploading potentially significant amounts of data to the homeserver.
// This implementation supports a configurable maximum file size limit in bytes. If a user tries to upload more than this, they will receive an error that their upload is too large.
// Uploaded files are processed piece-wise to avoid DoS attacks which would starve the server of memory.
// TODO: We should time out requests if they have not received any data within a configured timeout period.
func Upload(req *http.Request, cfg *config.MediaAPI, dev *userapi.Device, db storage.Database, activeThumbnailGeneration *types.ActiveThumbnailGeneration) util.JSONResponse {
r, resErr := parseAndValidateRequest(req, cfg, dev)
if resErr != nil {
return *resErr
}
if resErr = r.doUpload(req.Context(), req.Body, cfg, db, activeThumbnailGeneration); resErr != nil {
return *resErr
}
return util.JSONResponse{
Code: http.StatusOK,
JSON: uploadResponse{
ContentURI: fmt.Sprintf("mxc://%s/%s", cfg.Matrix.ServerName, r.MediaMetadata.MediaID),
},
}
}
// parseAndValidateRequest parses the incoming upload request to validate and extract
// all the metadata about the media being uploaded.
// Returns either an uploadRequest or an error formatted as a util.JSONResponse
func parseAndValidateRequest(req *http.Request, cfg *config.MediaAPI, dev *userapi.Device) (*uploadRequest, *util.JSONResponse) {
r := &uploadRequest{
MediaMetadata: &types.MediaMetadata{
Origin: cfg.Matrix.ServerName,
FileSizeBytes: types.FileSizeBytes(req.ContentLength),
ContentType: types.ContentType(req.Header.Get("Content-Type")),
UploadName: types.Filename(url.PathEscape(req.FormValue("filename"))),
UserID: types.MatrixUserID(dev.UserID),
},
Logger: util.GetLogger(req.Context()).WithField("Origin", cfg.Matrix.ServerName),
}
if resErr := r.Validate(*cfg.MaxFileSizeBytes); resErr != nil {
return nil, resErr
}
return r, nil
}
func (r *uploadRequest) generateMediaID(ctx context.Context, db storage.Database) (types.MediaID, error) {
for {
// First try generating a meda ID. We'll do this by
// generating some random bytes and then hex-encoding.
mediaIDBytes := make([]byte, 32)
_, err := rand.Read(mediaIDBytes)
if err != nil {
return "", fmt.Errorf("rand.Read: %w", err)
}
mediaID := types.MediaID(hex.EncodeToString(mediaIDBytes))
// Then we will check if this media ID already exists in
// our database. If it does then we had best generate a
// new one.
existingMetadata, err := db.GetMediaMetadata(ctx, mediaID, r.MediaMetadata.Origin)
if err != nil {
return "", fmt.Errorf("db.GetMediaMetadata: %w", err)
}
if existingMetadata != nil {
// The media ID was already used - repeat the process
// and generate a new one instead.
continue
}
// The media ID was not already used - let's return that.
return mediaID, nil
}
}
func (r *uploadRequest) doUpload(
ctx context.Context,
reqReader io.Reader,
cfg *config.MediaAPI,
db storage.Database,
activeThumbnailGeneration *types.ActiveThumbnailGeneration,
) *util.JSONResponse {
r.Logger.WithFields(log.Fields{
"UploadName": r.MediaMetadata.UploadName,
"FileSizeBytes": r.MediaMetadata.FileSizeBytes,
"ContentType": r.MediaMetadata.ContentType,
}).Info("Uploading file")
// The file data is hashed and the hash is used as the MediaID. The hash is useful as a
// method of deduplicating files to save storage, as well as a way to conduct
// integrity checks on the file data in the repository.
// Data is truncated to maxFileSizeBytes. Content-Length was reported as 0 < Content-Length <= maxFileSizeBytes so this is OK.
//
// TODO: This has a bad API shape where you either need to call:
// fileutils.RemoveDir(tmpDir, r.Logger)
// or call:
// r.storeFileAndMetadata(ctx, tmpDir, ...)
// before you return from doUpload else we will leak a temp file. We could make this nicer with a `WithTransaction` style of
// nested function to guarantee either storage or cleanup.
hash, bytesWritten, tmpDir, err := fileutils.WriteTempFile(ctx, reqReader, cfg.AbsBasePath)
if err != nil {
r.Logger.WithError(err).WithFields(log.Fields{
"MaxFileSizeBytes": *cfg.MaxFileSizeBytes,
}).Warn("Error while transferring file")
return &util.JSONResponse{
Code: http.StatusBadRequest,
JSON: jsonerror.Unknown("Failed to upload"),
}
}
// Check if temp file size exceeds max file size configuration
if bytesWritten > types.FileSizeBytes(*cfg.MaxFileSizeBytes) {
fileutils.RemoveDir(tmpDir, r.Logger) // delete temp file
return requestEntityTooLargeJSONResponse(*cfg.MaxFileSizeBytes)
}
// Look up the media by the file hash. If we already have the file but under a
// different media ID then we won't upload the file again - instead we'll just
// add a new metadata entry that refers to the same file.
existingMetadata, err := db.GetMediaMetadataByHash(
ctx, hash, r.MediaMetadata.Origin,
)
if err != nil {
fileutils.RemoveDir(tmpDir, r.Logger)
r.Logger.WithError(err).Error("Error querying the database by hash.")
resErr := jsonerror.InternalServerError()
return &resErr
}
if existingMetadata != nil {
// The file already exists, delete the uploaded temporary file.
defer fileutils.RemoveDir(tmpDir, r.Logger)
// The file already exists. Make a new media ID up for it.
mediaID, merr := r.generateMediaID(ctx, db)
if merr != nil {
r.Logger.WithError(merr).Error("Failed to generate media ID for existing file")
resErr := jsonerror.InternalServerError()
return &resErr
}
// Then amend the upload metadata.
r.MediaMetadata = &types.MediaMetadata{
MediaID: mediaID,
Origin: r.MediaMetadata.Origin,
ContentType: r.MediaMetadata.ContentType,
FileSizeBytes: r.MediaMetadata.FileSizeBytes,
CreationTimestamp: r.MediaMetadata.CreationTimestamp,
UploadName: r.MediaMetadata.UploadName,
Base64Hash: hash,
UserID: r.MediaMetadata.UserID,
}
} else {
// The file doesn't exist. Update the request metadata.
r.MediaMetadata.FileSizeBytes = bytesWritten
r.MediaMetadata.Base64Hash = hash
r.MediaMetadata.MediaID, err = r.generateMediaID(ctx, db)
if err != nil {
fileutils.RemoveDir(tmpDir, r.Logger)
r.Logger.WithError(err).Error("Failed to generate media ID for new upload")
resErr := jsonerror.InternalServerError()
return &resErr
}
}
r.Logger = r.Logger.WithField("media_id", r.MediaMetadata.MediaID)
r.Logger.WithFields(log.Fields{
"Base64Hash": r.MediaMetadata.Base64Hash,
"UploadName": r.MediaMetadata.UploadName,
"FileSizeBytes": r.MediaMetadata.FileSizeBytes,
"ContentType": r.MediaMetadata.ContentType,
}).Info("File uploaded")
return r.storeFileAndMetadata(
ctx, tmpDir, cfg.AbsBasePath, db, cfg.ThumbnailSizes,
activeThumbnailGeneration, cfg.MaxThumbnailGenerators,
)
}
func requestEntityTooLargeJSONResponse(maxFileSizeBytes config.FileSizeBytes) *util.JSONResponse {
return &util.JSONResponse{
Code: http.StatusRequestEntityTooLarge,
JSON: jsonerror.Unknown(fmt.Sprintf("HTTP Content-Length is greater than the maximum allowed upload size (%v).", maxFileSizeBytes)),
}
}
// Validate validates the uploadRequest fields
func (r *uploadRequest) Validate(maxFileSizeBytes config.FileSizeBytes) *util.JSONResponse {
if maxFileSizeBytes > 0 && r.MediaMetadata.FileSizeBytes > types.FileSizeBytes(maxFileSizeBytes) {
return requestEntityTooLargeJSONResponse(maxFileSizeBytes)
}
if strings.HasPrefix(string(r.MediaMetadata.UploadName), "~") {
return &util.JSONResponse{
Code: http.StatusBadRequest,
JSON: jsonerror.Unknown("File name must not begin with '~'."),
}
}
// TODO: Validate filename - what are the valid characters?
if r.MediaMetadata.UserID != "" {
// TODO: We should put user ID parsing code into gomatrixserverlib and use that instead
// (see https://github.com/matrix-org/gomatrixserverlib/blob/3394e7c7003312043208aa73727d2256eea3d1f6/eventcontent.go#L347 )
// It should be a struct (with pointers into a single string to avoid copying) and
// we should update all refs to use UserID types rather than strings.
// https://github.com/matrix-org/synapse/blob/v0.19.2/synapse/types.py#L92
if _, _, err := gomatrixserverlib.SplitID('@', string(r.MediaMetadata.UserID)); err != nil {
return &util.JSONResponse{
Code: http.StatusBadRequest,
JSON: jsonerror.BadJSON("user id must be in the form @localpart:domain"),
}
}
}
return nil
}
// storeFileAndMetadata moves the temporary file to its final path based on metadata and stores the metadata in the database
// See getPathFromMediaMetadata in fileutils for details of the final path.
// The order of operations is important as it avoids metadata entering the database before the file
// is ready, and if we fail to move the file, it never gets added to the database.
// Returns a util.JSONResponse error and cleans up directories in case of error.
func (r *uploadRequest) storeFileAndMetadata(
ctx context.Context,
tmpDir types.Path,
absBasePath config.Path,
db storage.Database,
thumbnailSizes []config.ThumbnailSize,
activeThumbnailGeneration *types.ActiveThumbnailGeneration,
maxThumbnailGenerators int,
) *util.JSONResponse {
finalPath, duplicate, err := fileutils.MoveFileWithHashCheck(tmpDir, r.MediaMetadata, absBasePath, r.Logger)
if err != nil {
r.Logger.WithError(err).Error("Failed to move file.")
return &util.JSONResponse{
Code: http.StatusBadRequest,
JSON: jsonerror.Unknown("Failed to upload"),
}
}
if duplicate {
r.Logger.WithField("dst", finalPath).Info("File was stored previously - discarding duplicate")
}
if err = db.StoreMediaMetadata(ctx, r.MediaMetadata); err != nil {
r.Logger.WithError(err).Warn("Failed to store metadata")
// If the file is a duplicate (has the same hash as an existing file) then
// there is valid metadata in the database for that file. As such we only
// remove the file if it is not a duplicate.
if !duplicate {
fileutils.RemoveDir(types.Path(path.Dir(string(finalPath))), r.Logger)
}
return &util.JSONResponse{
Code: http.StatusBadRequest,
JSON: jsonerror.Unknown("Failed to upload"),
}
}
go func() {
busy, err := thumbnailer.GenerateThumbnails(
context.Background(), finalPath, thumbnailSizes, r.MediaMetadata,
activeThumbnailGeneration, maxThumbnailGenerators, db, r.Logger,
)
if err != nil {
r.Logger.WithError(err).Warn("Error generating thumbnails")
}
if busy {
r.Logger.Warn("Maximum number of active thumbnail generators reached. Skipping pre-generation.")
}
}()
return nil
}