Propagate errors sensibly from proxied IS requests

synapse/api/errors.py

@@ -66,6 +66,17 @@ def error_dict(self):
         return cs_error(self.msg)
 
 
+class MatrixCodeMessageException(CodeMessageException):
+    """An error from a general matrix endpoint, eg. from a proxied Matrix API call.
+
+    Attributes:
+        errcode (str): Matrix error code e.g 'M_FORBIDDEN'
+    """
+    def __init__(self, code, msg, errcode=Codes.UNKNOWN):
+        super(MatrixCodeMessageException, self).__init__(code, msg)
+        self.errcode = errcode
+
+
 class SynapseError(CodeMessageException):
     """A base exception type for matrix errors which have an errcode and error
     message (as well as an HTTP status code).

synapse/handlers/identity.py

@@ -18,7 +18,7 @@
 from twisted.internet import defer
 
 from synapse.api.errors import (
-    CodeMessageException
+    MatrixCodeMessageException, CodeMessageException
 )
 from ._base import BaseHandler
 from synapse.util.async import run_on_reactor
@@ -90,6 +90,9 @@ def threepid_from_creds(self, creds):
                 ),
                 {'sid': creds['sid'], 'client_secret': client_secret}
             )
+        except MatrixCodeMessageException as e:
+            logger.info("getValidated3pid failed with Matrix error: %r", e)
+            raise SynapseError(e.code, e.msg, e.errcode)
         except CodeMessageException as e:
             data = json.loads(e.msg)
 
@@ -159,6 +162,9 @@ def requestEmailToken(self, id_server, email, client_secret, send_attempt, **kwa
                 params
             )
             defer.returnValue(data)
+        except MatrixCodeMessageException as e:
+            logger.info("Proxied requestToken failed with Matrix error: %r", e)
+            raise SynapseError(e.code, e.msg, e.errcode)
         except CodeMessageException as e:
             logger.info("Proxied requestToken failed: %r", e)
             raise e
@@ -193,6 +199,9 @@ def requestMsisdnToken(
                 params
             )
             defer.returnValue(data)
+        except MatrixCodeMessageException as e:
+            logger.info("Proxied requestToken failed with Matrix error: %r", e)
+            raise SynapseError(e.code, e.msg, e.errcode)
         except CodeMessageException as e:
             logger.info("Proxied requestToken failed: %r", e)
             raise e

synapse/http/client.py

@@ -16,7 +16,7 @@
 from OpenSSL.SSL import VERIFY_NONE
 
 from synapse.api.errors import (
-    CodeMessageException, SynapseError, Codes,
+    CodeMessageException, MatrixCodeMessageException, SynapseError, Codes,
 )
 from synapse.util.logcontext import preserve_context_over_fn
 import synapse.metrics
@@ -145,6 +145,11 @@ def post_json_get_json(self, uri, post_json):
 
         body = yield preserve_context_over_fn(readBody, response)
 
+        if 200 <= response.code < 300:
+            defer.returnValue(json.loads(body))
+        else:
+            raise self._exceptionFromFailedRequest(response, body)
+
         defer.returnValue(json.loads(body))
 
     @defer.inlineCallbacks
@@ -164,8 +169,11 @@ def get_json(self, uri, args={}):
             On a non-2xx HTTP response. The response body will be used as the
             error message.
         """
-        body = yield self.get_raw(uri, args)
-        defer.returnValue(json.loads(body))
+        try:
+            body = yield self.get_raw(uri, args)
+            defer.returnValue(json.loads(body))
+        except CodeMessageException as e:
+            raise self._exceptionFromFailedRequest(e.code, e.msg)
 
     @defer.inlineCallbacks
     def put_json(self, uri, json_body, args={}):
@@ -246,6 +254,15 @@ def get_raw(self, uri, args={}):
         else:
             raise CodeMessageException(response.code, body)
 
+    def _exceptionFromFailedRequest(self, response, body):
+        try:
+            jsonBody = json.loads(body)
+            errcode = jsonBody['errcode']
+            error = jsonBody['error']
+            return MatrixCodeMessageException(response.code, error, errcode)
+        except (ValueError, KeyError):
+            return CodeMessageException(response.code, body)
+
     # XXX: FIXME: This is horribly copy-pasted from matrixfederationclient.
     # The two should be factored out.