summary refs log tree commit diff
path: root/synapse/http/server.py
blob: 8502416fca2ed3451b1beae4f162877fa1519176 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
# -*- coding: utf-8 -*-
# Copyright 2014 matrix.org
#
# 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 syutil.jsonutil import (
    encode_canonical_json, encode_pretty_printed_json
)
from synapse.api.errors import cs_exception, SynapseError, CodeMessageException
from synapse.util.stringutils import random_string

from twisted.internet import defer, reactor
from twisted.web import server, resource
from twisted.web.server import NOT_DONE_YET
from twisted.web.util import redirectTo

import base64
import collections
import json
import logging
import os


logger = logging.getLogger(__name__)


class HttpServer(object):
    """ Interface for registering callbacks on a HTTP server
    """

    def register_path(self, method, path_pattern, callback):
        """ Register a callback that get's fired if we receive a http request
        with the given method for a path that matches the given regex.

        If the regex contains groups these get's passed to the calback via
        an unpacked tuple.

        Args:
            method (str): The method to listen to.
            path_pattern (str): The regex used to match requests.
            callback (function): The function to fire if we receive a matched
                request. The first argument will be the request object and
                subsequent arguments will be any matched groups from the regex.
                This should return a tuple of (code, response).
        """
        pass


class JsonResource(HttpServer, resource.Resource):
    """ This implements the HttpServer interface and provides JSON support for
    Resources.

    Register callbacks via register_path()
    """

    isLeaf = True

    _PathEntry = collections.namedtuple("_PathEntry", ["pattern", "callback"])

    def __init__(self):
        resource.Resource.__init__(self)

        self.path_regexs = {}

    def register_path(self, method, path_pattern, callback):
        self.path_regexs.setdefault(method, []).append(
            self._PathEntry(path_pattern, callback)
        )

    def start_listening(self, port):
        """ Registers the http server with the twisted reactor.

        Args:
            port (int): The port to listen on.

        """
        reactor.listenTCP(port, server.Site(self))

    # Gets called by twisted
    def render(self, request):
        """ This get's called by twisted every time someone sends us a request.
        """
        self._async_render(request)
        return server.NOT_DONE_YET

    @defer.inlineCallbacks
    def _async_render(self, request):
        """ This get's called by twisted every time someone sends us a request.
            This checks if anyone has registered a callback for that method and
            path.
        """
        try:
            # Just say yes to OPTIONS.
            if request.method == "OPTIONS":
                self._send_response(request, 200, {})
                return

            # Loop through all the registered callbacks to check if the method
            # and path regex match
            for path_entry in self.path_regexs.get(request.method, []):
                m = path_entry.pattern.match(request.path)
                if m:
                    # We found a match! Trigger callback and then return the
                    # returned response. We pass both the request and any
                    # matched groups from the regex to the callback.
                    code, response = yield path_entry.callback(
                        request,
                        *m.groups()
                    )

                    self._send_response(request, code, response)
                    return

            # Huh. No one wanted to handle that? Fiiiiiine. Send 400.
            self._send_response(
                request,
                400,
                {"error": "Unrecognized request"}
            )
        except CodeMessageException as e:
            logger.exception(e)
            self._send_response(
                request,
                e.code,
                cs_exception(e)
            )
        except Exception as e:
            logger.exception(e)
            self._send_response(
                request,
                500,
                {"error": "Internal server error"}
            )

    def _send_response(self, request, code, response_json_object):

        if not self._request_user_agent_is_curl(request):
            json_bytes = encode_canonical_json(response_json_object)
        else:
            json_bytes = encode_pretty_printed_json(response_json_object)

        # TODO: Only enable CORS for the requests that need it.
        respond_with_json_bytes(request, code, json_bytes, send_cors=True)

    @staticmethod
    def _request_user_agent_is_curl(request):
        user_agents = request.requestHeaders.getRawHeaders(
            "User-Agent", default=[]
        )
        for user_agent in user_agents:
            if "curl" in user_agent:
                return True
        return False


class RootRedirect(resource.Resource):
    """Redirects the root '/' path to another path."""

    def __init__(self, path):
        resource.Resource.__init__(self)
        self.url = path

    def render_GET(self, request):
        return redirectTo(self.url, request)

    def getChild(self, name, request):
        if len(name) == 0:
            return self  # select ourselves as the child to render
        return resource.Resource.getChild(self, name, request)


class FileUploadResource(resource.Resource):
    isLeaf = True

    def __init__(self, directory, auth, file_map_func=None):
        resource.Resource.__init__(self)
        self.directory = directory
        self.auth = auth
        if not file_map_func:
            file_map_func = self.map_request_to_name
        self.get_name_for_request = file_map_func

        if not os.path.isdir(self.directory):
            os.mkdir(self.directory)
            logger.info("FileUploadResource : 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.
        suffix = ""
        if request.requestHeaders.hasHeader("Content-Type"):
            content_type = request.requestHeaders.getRawHeaders(
                "Content-Type")[0]
            if (content_type.split("/")[0].lower() in
                    ["image", "video", "audio"]):
                suffix = "." + content_type.split("/")[-1]

        file_path = os.path.join(self.directory, prefix + main_part + suffix)
        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_path = os.path.join(self.directory,
                                     prefix + main_part + suffix)
            attempts += 1
            if attempts > 25:  # really? Really?
                raise SynapseError(500, "Unable to create file.")

        defer.returnValue(file_path)

    def render_POST(self, request):
        self._async_render(request)
        return server.NOT_DONE_YET

    @defer.inlineCallbacks
    def _async_render(self, request):
        try:
            fname = yield self.get_name_for_request(request)

            with open(fname, "wb") as f:
                f.write(request.content.read())

            respond_with_json_bytes(request, 200,
                                    json.dumps({"path": fname}),
                                    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)


def respond_with_json_bytes(request, code, json_bytes, send_cors=False):
    """Sends encoded JSON in response to the given request.

    Args:
        request (twisted.web.http.Request): The http request to respond to.
        code (int): The HTTP response code.
        json_bytes (bytes): The json bytes to use as the response body.
        send_cors (bool): Whether to send Cross-Origin Resource Sharing headers
            http://www.w3.org/TR/cors/
    Returns:
        twisted.web.server.NOT_DONE_YET"""

    request.setResponseCode(code)
    request.setHeader(b"Content-Type", b"application/json")

    if send_cors:
        request.setHeader("Access-Control-Allow-Origin", "*")
        request.setHeader("Access-Control-Allow-Methods",
                          "GET, POST, PUT, DELETE, OPTIONS")
        request.setHeader("Access-Control-Allow-Headers",
                          "Origin, X-Requested-With, Content-Type, Accept")

    request.write(json_bytes)
    request.finish()
    return NOT_DONE_YET