diff options
Diffstat (limited to 'synapse/rest/media')
| -rw-r--r-- | synapse/rest/media/v1/base_resource.py | 1 | ||||
| -rw-r--r-- | synapse/rest/media/v1/media_repository.py | 7 | ||||
| -rw-r--r-- | synapse/rest/media/v1/preview_url_resource.py | 462 | ||||
| -rw-r--r-- | synapse/rest/media/v1/thumbnail_resource.py | 22 |
4 files changed, 492 insertions, 0 deletions
diff --git a/synapse/rest/media/v1/base_resource.py b/synapse/rest/media/v1/base_resource.py index 58ef91c0b8..2b1938dc8e 100644 --- a/synapse/rest/media/v1/base_resource.py +++ b/synapse/rest/media/v1/base_resource.py @@ -72,6 +72,7 @@ class BaseMediaResource(Resource): self.store = hs.get_datastore() self.max_upload_size = hs.config.max_upload_size self.max_image_pixels = hs.config.max_image_pixels + self.max_spider_size = hs.config.max_spider_size self.filepaths = filepaths self.version_string = hs.version_string self.downloads = {} diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py index 7dfb027dd1..97b7e84af9 100644 --- a/synapse/rest/media/v1/media_repository.py +++ b/synapse/rest/media/v1/media_repository.py @@ -17,6 +17,7 @@ from .upload_resource import UploadResource from .download_resource import DownloadResource from .thumbnail_resource import ThumbnailResource from .identicon_resource import IdenticonResource +from .preview_url_resource import PreviewUrlResource from .filepath import MediaFilePaths from twisted.web.resource import Resource @@ -78,3 +79,9 @@ class MediaRepositoryResource(Resource): self.putChild("download", DownloadResource(hs, filepaths)) self.putChild("thumbnail", ThumbnailResource(hs, filepaths)) self.putChild("identicon", IdenticonResource()) + if hs.config.url_preview_enabled: + try: + self.putChild("preview_url", PreviewUrlResource(hs, filepaths)) + except Exception as e: + logger.warn("Failed to mount preview_url") + logger.exception(e) diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py new file mode 100644 index 0000000000..8464fc0176 --- /dev/null +++ b/synapse/rest/media/v1/preview_url_resource.py @@ -0,0 +1,462 @@ +# -*- coding: utf-8 -*- +# Copyright 2016 OpenMarket 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. + +from .base_resource import BaseMediaResource + +from twisted.web.server import NOT_DONE_YET +from twisted.internet import defer +from urlparse import urlparse, urlsplit, urlunparse + +from synapse.api.errors import ( + SynapseError, Codes, +) +from synapse.util.stringutils import random_string +from synapse.util.caches.expiringcache import ExpiringCache +from synapse.http.client import SpiderHttpClient +from synapse.http.server import ( + request_handler, respond_with_json_bytes +) +from synapse.util.async import ObservableDeferred +from synapse.util.stringutils import is_ascii + +import os +import re +import fnmatch +import cgi +import ujson as json + +import logging +logger = logging.getLogger(__name__) + +try: + from lxml import html +except ImportError: + pass + + +class PreviewUrlResource(BaseMediaResource): + isLeaf = True + + def __init__(self, hs, filepaths): + try: + if html: + pass + except: + raise RuntimeError("Disabling PreviewUrlResource as lxml not available") + + if not hasattr(hs.config, "url_preview_ip_range_blacklist"): + logger.warn( + "For security, you must specify an explicit target IP address " + "blacklist in url_preview_ip_range_blacklist for url previewing " + "to work" + ) + raise RuntimeError( + "Disabling PreviewUrlResource as " + "url_preview_ip_range_blacklist not specified" + ) + + BaseMediaResource.__init__(self, hs, filepaths) + self.client = SpiderHttpClient(hs) + if hasattr(hs.config, "url_preview_url_blacklist"): + self.url_preview_url_blacklist = hs.config.url_preview_url_blacklist + + # simple memory cache mapping urls to OG metadata + self.cache = ExpiringCache( + cache_name="url_previews", + clock=self.clock, + # don't spider URLs more often than once an hour + expiry_ms=60 * 60 * 1000, + ) + self.cache.start() + + self.downloads = {} + + def render_GET(self, request): + self._async_render_GET(request) + return NOT_DONE_YET + + @request_handler + @defer.inlineCallbacks + def _async_render_GET(self, request): + + # XXX: if get_user_by_req fails, what should we do in an async render? + requester = yield self.auth.get_user_by_req(request) + url = request.args.get("url")[0] + if "ts" in request.args: + ts = int(request.args.get("ts")[0]) + else: + ts = self.clock.time_msec() + + # impose the URL pattern blacklist + if hasattr(self, "url_preview_url_blacklist"): + url_tuple = urlsplit(url) + for entry in self.url_preview_url_blacklist: + match = True + for attrib in entry: + pattern = entry[attrib] + value = getattr(url_tuple, attrib) + logger.debug(( + "Matching attrib '%s' with value '%s' against" + " pattern '%s'" + ) % (attrib, value, pattern)) + + if value is None: + match = False + continue + + if pattern.startswith('^'): + if not re.match(pattern, getattr(url_tuple, attrib)): + match = False + continue + else: + if not fnmatch.fnmatch(getattr(url_tuple, attrib), pattern): + match = False + continue + if match: + logger.warn( + "URL %s blocked by url_blacklist entry %s", url, entry + ) + raise SynapseError( + 403, "URL blocked by url pattern blacklist entry", + Codes.UNKNOWN + ) + + # first check the memory cache - good to handle all the clients on this + # HS thundering away to preview the same URL at the same time. + og = self.cache.get(url) + if og: + respond_with_json_bytes(request, 200, json.dumps(og), send_cors=True) + return + + # then check the URL cache in the DB (which will also provide us with + # historical previews, if we have any) + cache_result = yield self.store.get_url_cache(url, ts) + if ( + cache_result and + cache_result["download_ts"] + cache_result["expires"] > ts and + cache_result["response_code"] / 100 == 2 + ): + respond_with_json_bytes( + request, 200, cache_result["og"].encode('utf-8'), + send_cors=True + ) + return + + # Ensure only one download for a given URL is active at a time + download = self.downloads.get(url) + if download is None: + download = self._download_url(url, requester.user) + download = ObservableDeferred( + download, + consumeErrors=True + ) + self.downloads[url] = download + + @download.addBoth + def callback(media_info): + del self.downloads[url] + return media_info + media_info = yield download.observe() + + # FIXME: we should probably update our cache now anyway, so that + # even if the OG calculation raises, we don't keep hammering on the + # remote server. For now, leave it uncached to aid debugging OG + # calculation problems + + logger.debug("got media_info of '%s'" % media_info) + + if self._is_media(media_info['media_type']): + dims = yield self._generate_local_thumbnails( + media_info['filesystem_id'], media_info + ) + + og = { + "og:description": media_info['download_name'], + "og:image": "mxc://%s/%s" % ( + self.server_name, media_info['filesystem_id'] + ), + "og:image:type": media_info['media_type'], + "matrix:image:size": media_info['media_length'], + } + + if dims: + og["og:image:width"] = dims['width'] + og["og:image:height"] = dims['height'] + else: + logger.warn("Couldn't get dims for %s" % url) + + # define our OG response for this media + elif self._is_html(media_info['media_type']): + # TODO: somehow stop a big HTML tree from exploding synapse's RAM + + try: + tree = html.parse(media_info['filename']) + og = yield self._calc_og(tree, media_info, requester) + except UnicodeDecodeError: + # XXX: evil evil bodge + # Empirically, sites like google.com mix Latin-1 and utf-8 + # encodings in the same page. The rogue Latin-1 characters + # cause lxml to choke with a UnicodeDecodeError, so if we + # see this we go and do a manual decode of the HTML before + # handing it to lxml as utf-8 encoding, counter-intuitively, + # which seems to make it happier... + file = open(media_info['filename']) + body = file.read() + file.close() + tree = html.fromstring(body.decode('utf-8', 'ignore')) + og = yield self._calc_og(tree, media_info, requester) + + else: + logger.warn("Failed to find any OG data in %s", url) + og = {} + + logger.debug("Calculated OG for %s as %s" % (url, og)) + + # store OG in ephemeral in-memory cache + self.cache[url] = og + + # store OG in history-aware DB cache + yield self.store.store_url_cache( + url, + media_info["response_code"], + media_info["etag"], + media_info["expires"], + json.dumps(og), + media_info["filesystem_id"], + media_info["created_ts"], + ) + + respond_with_json_bytes(request, 200, json.dumps(og), send_cors=True) + + + @defer.inlineCallbacks + def _calc_og(self, tree, media_info, requester): + # suck our tree into lxml and define our OG response. + + # if we see any image URLs in the OG response, then spider them + # (although the client could choose to do this by asking for previews of those + # URLs to avoid DoSing the server) + + # "og:type" : "video", + # "og:url" : "https://www.youtube.com/watch?v=LXDBoHyjmtw", + # "og:site_name" : "YouTube", + # "og:video:type" : "application/x-shockwave-flash", + # "og:description" : "Fun stuff happening here", + # "og:title" : "RemoteJam - Matrix team hack for Disrupt Europe Hackathon", + # "og:image" : "https://i.ytimg.com/vi/LXDBoHyjmtw/maxresdefault.jpg", + # "og:video:url" : "http://www.youtube.com/v/LXDBoHyjmtw?version=3&autohide=1", + # "og:video:width" : "1280" + # "og:video:height" : "720", + # "og:video:secure_url": "https://www.youtube.com/v/LXDBoHyjmtw?version=3", + + og = {} + for tag in tree.xpath("//*/meta[starts-with(@property, 'og:')]"): + og[tag.attrib['property']] = tag.attrib['content'] + + # TODO: grab article: meta tags too, e.g.: + + # "article:publisher" : "https://www.facebook.com/thethudonline" /> + # "article:author" content="https://www.facebook.com/thethudonline" /> + # "article:tag" content="baby" /> + # "article:section" content="Breaking News" /> + # "article:published_time" content="2016-03-31T19:58:24+00:00" /> + # "article:modified_time" content="2016-04-01T18:31:53+00:00" /> + + if 'og:title' not in og: + # do some basic spidering of the HTML + title = tree.xpath("(//title)[1] | (//h1)[1] | (//h2)[1] | (//h3)[1]") + og['og:title'] = title[0].text.strip() if title else None + + if 'og:image' not in og: + # TODO: extract a favicon failing all else + meta_image = tree.xpath( + "//*/meta[translate(@itemprop, 'IMAGE', 'image')='image']/@content" + ) + if meta_image: + og['og:image'] = self._rebase_url(meta_image[0], media_info['uri']) + else: + # TODO: consider inlined CSS styles as well as width & height attribs + images = tree.xpath("//img[@src][number(@width)>10][number(@height)>10]") + images = sorted(images, key=lambda i: ( + -1 * int(i.attrib['width']) * int(i.attrib['height']) + )) + if not images: + images = tree.xpath("//img[@src]") + if images: + og['og:image'] = images[0].attrib['src'] + + # pre-cache the image for posterity + # FIXME: it might be cleaner to use the same flow as the main /preview_url request + # itself and benefit from the same caching etc. But for now we just rely on the + # caching on the master request to speed things up. + if 'og:image' in og and og['og:image']: + image_info = yield self._download_url( + self._rebase_url(og['og:image'], media_info['uri']), requester.user + ) + + if self._is_media(image_info['media_type']): + # TODO: make sure we don't choke on white-on-transparent images + dims = yield self._generate_local_thumbnails( + image_info['filesystem_id'], image_info + ) + if dims: + og["og:image:width"] = dims['width'] + og["og:image:height"] = dims['height'] + else: + logger.warn("Couldn't get dims for %s" % og["og:image"]) + + og["og:image"] = "mxc://%s/%s" % ( + self.server_name, image_info['filesystem_id'] + ) + og["og:image:type"] = image_info['media_type'] + og["matrix:image:size"] = image_info['media_length'] + else: + del og["og:image"] + + if 'og:description' not in og: + meta_description = tree.xpath( + "//*/meta" + "[translate(@name, 'DESCRIPTION', 'description')='description']" + "/@content") + if meta_description: + og['og:description'] = meta_description[0] + else: + # grab any text nodes which are inside the <body/> tag... + # unless they are within an HTML5 semantic markup tag... + # <header/>, <nav/>, <aside/>, <footer/> + # ...or if they are within a <script/> or <style/> tag. + # This is a very very very coarse approximation to a plain text + # render of the page. + text_nodes = tree.xpath("//text()[not(ancestor::header | ancestor::nav | " + "ancestor::aside | ancestor::footer | " + "ancestor::script | ancestor::style)]" + + "[ancestor::body]") + text = '' + for text_node in text_nodes: + if len(text) < 500: + text += text_node + ' ' + else: + break + text = re.sub(r'[\t ]+', ' ', text) + text = re.sub(r'[\t \r\n]*[\r\n]+', '\n', text) + text = text.strip()[:500] + og['og:description'] = text if text else None + + # TODO: delete the url downloads to stop diskfilling, + # as we only ever cared about its OG + defer.returnValue(og) + + def _rebase_url(self, url, base): + base = list(urlparse(base)) + url = list(urlparse(url)) + if not url[0]: # fix up schema + url[0] = base[0] or "http" + if not url[1]: # fix up hostname + url[1] = base[1] + if not url[2].startswith('/'): + url[2] = re.sub(r'/[^/]+$', '/', base[2]) + url[2] + return urlunparse(url) + + @defer.inlineCallbacks + def _download_url(self, url, user): + # TODO: we should probably honour robots.txt... except in practice + # we're most likely being explicitly triggered by a human rather than a + # bot, so are we really a robot? + + # XXX: horrible duplication with base_resource's _download_remote_file() + file_id = random_string(24) + + fname = self.filepaths.local_media_filepath(file_id) + self._makedirs(fname) + + try: + with open(fname, "wb") as f: + logger.debug("Trying to get url '%s'" % url) + length, headers, uri, code = yield self.client.get_file( + url, output_stream=f, max_size=self.max_spider_size, + ) + # FIXME: pass through 404s and other error messages nicely + + media_type = headers["Content-Type"][0] + time_now_ms = self.clock.time_msec() + + content_disposition = headers.get("Content-Disposition", None) + if content_disposition: + _, params = cgi.parse_header(content_disposition[0],) + download_name = None + + # First check if there is a valid UTF-8 filename + download_name_utf8 = params.get("filename*", None) + if download_name_utf8: + if download_name_utf8.lower().startswith("utf-8''"): + download_name = download_name_utf8[7:] + + # If there isn't check for an ascii name. + if not download_name: + download_name_ascii = params.get("filename", None) + if download_name_ascii and is_ascii(download_name_ascii): + download_name = download_name_ascii + + if download_name: + download_name = urlparse.unquote(download_name) + try: + download_name = download_name.decode("utf-8") + except UnicodeDecodeError: + download_name = None + else: + download_name = None + + yield self.store.store_local_media( + media_id=file_id, + media_type=media_type, + time_now_ms=self.clock.time_msec(), + upload_name=download_name, + media_length=length, + user_id=user, + ) + + except Exception as e: + os.remove(fname) + raise SynapseError( + 500, ("Failed to download content: %s" % e), + Codes.UNKNOWN + ) + + defer.returnValue({ + "media_type": media_type, + "media_length": length, + "download_name": download_name, + "created_ts": time_now_ms, + "filesystem_id": file_id, + "filename": fname, + "uri": uri, + "response_code": code, + # FIXME: we should calculate a proper expiration based on the + # Cache-Control and Expire headers. But for now, assume 1 hour. + "expires": 60 * 60 * 1000, + "etag": headers["ETag"][0] if "ETag" in headers else None, + }) + + def _is_media(self, content_type): + if content_type.lower().startswith("image/"): + return True + + def _is_html(self, content_type): + content_type = content_type.lower() + if ( + content_type.startswith("text/html") or + content_type.startswith("application/xhtml") + ): + return True diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py index ab52499785..513b445688 100644 --- a/synapse/rest/media/v1/thumbnail_resource.py +++ b/synapse/rest/media/v1/thumbnail_resource.py @@ -72,6 +72,11 @@ class ThumbnailResource(BaseMediaResource): self._respond_404(request) return + if media_info["media_type"] == "image/svg+xml": + file_path = self.filepaths.local_media_filepath(media_id) + yield self._respond_with_file(request, media_info["media_type"], file_path) + return + thumbnail_infos = yield self.store.get_local_media_thumbnails(media_id) if thumbnail_infos: @@ -103,6 +108,11 @@ class ThumbnailResource(BaseMediaResource): self._respond_404(request) return + if media_info["media_type"] == "image/svg+xml": + file_path = self.filepaths.local_media_filepath(media_id) + yield self._respond_with_file(request, media_info["media_type"], file_path) + return + thumbnail_infos = yield self.store.get_local_media_thumbnails(media_id) for info in thumbnail_infos: t_w = info["thumbnail_width"] == desired_width @@ -138,6 +148,11 @@ class ThumbnailResource(BaseMediaResource): desired_method, desired_type): media_info = yield self._get_remote_media(server_name, media_id) + if media_info["media_type"] == "image/svg+xml": + file_path = self.filepaths.remote_media_filepath(server_name, media_id) + yield self._respond_with_file(request, media_info["media_type"], file_path) + return + thumbnail_infos = yield self.store.get_remote_media_thumbnails( server_name, media_id, ) @@ -181,6 +196,11 @@ class ThumbnailResource(BaseMediaResource): # We should proxy the thumbnail from the remote server instead. media_info = yield self._get_remote_media(server_name, media_id) + if media_info["media_type"] == "image/svg+xml": + file_path = self.filepaths.remote_media_filepath(server_name, media_id) + yield self._respond_with_file(request, media_info["media_type"], file_path) + return + thumbnail_infos = yield self.store.get_remote_media_thumbnails( server_name, media_id, ) @@ -208,6 +228,8 @@ class ThumbnailResource(BaseMediaResource): @defer.inlineCallbacks def _respond_default_thumbnail(self, request, media_info, width, height, method, m_type): + # XXX: how is this meant to work? store.get_default_thumbnails + # appears to always return [] so won't this always 404? media_type = media_info["media_type"] top_level_type = media_type.split("/")[0] sub_type = media_type.split("/")[-1].split(";")[0] |