[tor-commits] [stem/master] Catch ORPort socket timeouts

[atagar at torproject.org]

commit 2e86567b0cbcae03ddf1bec335808cd51329c961
Author: Damian Johnson <atagar at torproject.org>
Date:   Wed Jan 23 11:50:49 2019 -0800

    Catch ORPort socket timeouts
    
    Oops. I added a timeout attribute but completely forgot to catch the resulting
    exceptions. Caught thanks to starlight...
    
      https://trac.torproject.org/projects/tor/ticket/28961
    
      Traceback (most recent call last):
        File "../download_descriptor.py", line 133, in <module>
          main()
        File "../download_descriptor.py", line 115, in main
          endpoints = [args.download_from],
        File "/usr/local/lib/python3.7/site-packages/stem/descriptor/remote.py", line 485, in run
          return list(self._run(suppress))
        File "/usr/local/lib/python3.7/site-packages/stem/descriptor/remote.py", line 496, in _run
          raise self.error
        File "/usr/local/lib/python3.7/site-packages/stem/descriptor/remote.py", line 561, in _download_descriptors
          self.content, self.reply_headers = _download_from_orport(endpoint, self.compression, self.resource)
        File "/usr/local/lib/python3.7/site-packages/stem/descriptor/remote.py", line 962, in _download_from_orport
          with relay.create_circuit() as circ:
        File "/usr/local/lib/python3.7/site-packages/stem/client/__init__.py", line 207, in create_circuit
          for cell in self._msg(create_fast_cell):
        File "/usr/local/lib/python3.7/site-packages/stem/client/__init__.py", line 160, in _msg
          response = self._orport.recv(timeout = 1)
        File "/usr/local/lib/python3.7/site-packages/stem/socket.py", line 416, in recv
          return self._recv(wrapped_recv)
        File "/usr/local/lib/python3.7/site-packages/stem/socket.py", line 274, in _recv
          return handler(my_socket, my_socket_file)
        File "/usr/local/lib/python3.7/site-packages/stem/socket.py", line 410, in wrapped_recv
          return s.recv()
        File "/usr/local/lib/python3.7/ssl.py", line 1037, in recv
          return self.read(buflen)
        File "/usr/local/lib/python3.7/ssl.py", line 913, in read
          return self._sslobj.read(len)
      socket.timeout: The read operation timed out
    
    Through experimentation I also managed to get the following too...
    
      Traceback (most recent call last):
        File "download_descriptor.py", line 131, in <module>
          main()
        File "download_descriptor.py", line 113, in main
          endpoints = [args.download_from],
        File "/home/atagar/Desktop/stem/stem/descriptor/remote.py", line 485, in run
          return list(self._run(suppress))
        File "/home/atagar/Desktop/stem/stem/descriptor/remote.py", line 496, in _run
          raise self.error
      ssl.SSLError: ('The read operation timed out',)
    
    Unfortunately since this is an SSL socket (rather than a standard one) receive
    calls are liable to raise exceptions from both modules making this a bit of a
    whack-a-mole game (socket's docs are particularly bad about describing the
    array of exceptions that might get raised).
---
 stem/socket.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/stem/socket.py b/stem/socket.py
index 9290d6c6..80d29b83 100644
--- a/stem/socket.py
+++ b/stem/socket.py
@@ -408,7 +408,7 @@ class RelaySocket(BaseSocket):
 
         try:
           return s.recv()
-        except ssl.SSLWantReadError:
+        except (socket.timeout, ssl.SSLError, ssl.SSLWantReadError):
           return None
         finally:
           s.setblocking(1)