Write the upload portion of version 1 of the media repository

1 files changed, 212 insertions, 0 deletions

diff --git a/synapse/media/v0/content_repository.py b/synapse/media/v0/content_repository.py
new file mode 100644
index 0000000000..64ecb5346e
--- /dev/null
+++ b/synapse/media/v0/content_repository.py
@@ -0,0 +1,212 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014 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 .server import respond_with_json_bytes
+
+from synapse.util.stringutils import random_string
+from synapse.api.errors import (
+    cs_exception, SynapseError, CodeMessageException, Codes, cs_error
+)
+
+from twisted.protocols.basic import FileSender
+from twisted.web import server, resource
+from twisted.internet import defer
+
+import base64
+import json
+import logging
+import os
+import re
+
+logger = logging.getLogger(__name__)
+
+
+class ContentRepoResource(resource.Resource):
+    """Provides file uploading and downloading.
+
+    Uploads are POSTed to wherever this Resource is linked to. This resource
+    returns a "content token" which can be used to GET this content again. The
+    token is typically a path, but it may not be. Tokens can expire, be
+    one-time uses, etc.
+
+    In this case, the token is a path to the file and contains 3 interesting
+    sections:
+        - User ID base64d (for namespacing content to each user)
+        - random 24 char string
+        - Content type base64d (so we can return it when clients GET it)
+
+    """
+    isLeaf = True
+
+    def __init__(self, hs, directory, auth, external_addr):
+        resource.Resource.__init__(self)
+        self.hs = hs
+        self.directory = directory
+        self.auth = auth
+        self.external_addr = external_addr.rstrip('/')
+        self.max_upload_size = hs.config.max_upload_size
+
+        if not os.path.isdir(self.directory):
+            os.mkdir(self.directory)
+            logger.info("ContentRepoResource : Created %s directory.",
+                        self.directory)
+
+    @defer.inlineCallbacks
+    def map_request_to_name(self, request):
+        # auth the user
+        auth_user = yield self.auth.get_user_by_req(request)
+
+        # namespace all file uploads on the user
+        prefix = base64.urlsafe_b64encode(
+            auth_user.to_string()
+        ).replace('=', '')
+
+        # use a random string for the main portion
+        main_part = random_string(24)
+
+        # suffix with a file extension if we can make one. This is nice to
+        # provide a hint to clients on the file information. We will also reuse
+        # this info to spit back the content type to the client.
+        suffix = ""
+        if request.requestHeaders.hasHeader("Content-Type"):
+            content_type = request.requestHeaders.getRawHeaders(
+                "Content-Type")[0]
+            suffix = "." + base64.urlsafe_b64encode(content_type)
+            if (content_type.split("/")[0].lower() in
+                    ["image", "video", "audio"]):
+                file_ext = content_type.split("/")[-1]
+                # be a little paranoid and only allow a-z
+                file_ext = re.sub("[^a-z]", "", file_ext)
+                suffix += "." + file_ext
+
+        file_name = prefix + main_part + suffix
+        file_path = os.path.join(self.directory, file_name)
+        logger.info("User %s is uploading a file to path %s",
+                    auth_user.to_string(),
+                    file_path)
+
+        # keep trying to make a non-clashing file, with a sensible max attempts
+        attempts = 0
+        while os.path.exists(file_path):
+            main_part = random_string(24)
+            file_name = prefix + main_part + suffix
+            file_path = os.path.join(self.directory, file_name)
+            attempts += 1
+            if attempts > 25:  # really? Really?
+                raise SynapseError(500, "Unable to create file.")
+
+        defer.returnValue(file_path)
+
+    def render_GET(self, request):
+        # no auth here on purpose, to allow anyone to view, even across home
+        # servers.
+
+        # TODO: A little crude here, we could do this better.
+        filename = request.path.split('/')[-1]
+        # be paranoid
+        filename = re.sub("[^0-9A-z.-_]", "", filename)
+
+        file_path = self.directory + "/" + filename
+
+        logger.debug("Searching for %s", file_path)
+
+        if os.path.isfile(file_path):
+            # filename has the content type
+            base64_contentype = filename.split(".")[1]
+            content_type = base64.urlsafe_b64decode(base64_contentype)
+            logger.info("Sending file %s", file_path)
+            f = open(file_path, 'rb')
+            request.setHeader('Content-Type', content_type)
+
+            # cache for at least a day.
+            # XXX: we might want to turn this off for data we don't want to
+            # recommend caching as it's sensitive or private - or at least
+            # select private. don't bother setting Expires as all our matrix
+            # clients are smart enough to be happy with Cache-Control (right?)
+            request.setHeader(
+                "Cache-Control", "public,max-age=86400,s-maxage=86400"
+            )
+
+            d = FileSender().beginFileTransfer(f, request)
+
+            # after the file has been sent, clean up and finish the request
+            def cbFinished(ignored):
+                f.close()
+                request.finish()
+            d.addCallback(cbFinished)
+        else:
+            respond_with_json_bytes(
+                request,
+                404,
+                json.dumps(cs_error("Not found", code=Codes.NOT_FOUND)),
+                send_cors=True)
+
+        return server.NOT_DONE_YET
+
+    def render_POST(self, request):
+        self._async_render(request)
+        return server.NOT_DONE_YET
+
+    def render_OPTIONS(self, request):
+        respond_with_json_bytes(request, 200, {}, send_cors=True)
+        return server.NOT_DONE_YET
+
+    @defer.inlineCallbacks
+    def _async_render(self, request):
+        try:
+            # TODO: The checks here are a bit late. The content will have
+            # already been uploaded to a tmp file at this point
+            content_length = request.getHeader("Content-Length")
+            if content_length is None:
+                raise SynapseError(
+                    msg="Request must specify a Content-Length", code=400
+                )
+            if int(content_length) > self.max_upload_size:
+                raise SynapseError(
+                    msg="Upload request body is too large",
+                    code=413,
+                )
+
+            fname = yield self.map_request_to_name(request)
+
+            # TODO I have a suspicious feeling this is just going to block
+            with open(fname, "wb") as f:
+                f.write(request.content.read())
+
+            # FIXME (erikj): These should use constants.
+            file_name = os.path.basename(fname)
+            # FIXME: we can't assume what the repo's public mounted path is
+            # ...plus self-signed SSL won't work to remote clients anyway
+            # ...and we can't assume that it's SSL anyway, as we might want to
+            # serve it via the non-SSL listener...
+            url = "%s/_matrix/content/%s" % (
+                self.external_addr, file_name
+            )
+
+            respond_with_json_bytes(request, 200,
+                                    json.dumps({"content_token": url}),
+                                    send_cors=True)
+
+        except CodeMessageException as e:
+            logger.exception(e)
+            respond_with_json_bytes(request, e.code,
+                                    json.dumps(cs_exception(e)))
+        except Exception as e:
+            logger.error("Failed to store file: %s" % e)
+            respond_with_json_bytes(
+                request,
+                500,
+                json.dumps({"error": "Internal server error"}),
+                send_cors=True)