Susan Hinrichs created TS-3453:
----------------------------------

             Summary: Confusion of handling SSL events in write_to_net_io in 
UnixNetVConnection.cc
                 Key: TS-3453
                 URL: https://issues.apache.org/jira/browse/TS-3453
             Project: Traffic Server
          Issue Type: Bug
          Components: SSL
            Reporter: Susan Hinrichs


While tracking down differences for SSL between 5.0 and 5.2 for TS- I came 
across odd event handling code in write_to_net_io in UnixNetVConnection.cc.  
Looking back at the history in that code things became even more confusing.

The current version on master (same as what is in 5.2) contains the following 
in an if/else sequence. SSL IOs can return READ events event from write 
functions (and visa versa), so that is why I assume that this write function is 
dealing with SSL read events at all.

{code}
if (ret == SSL_HANDSHAKE_WANT_READ || ret == SSL_HANDSHAKE_WANT_ACCEPT || ret 
== SSL_HANDSHAKE_WANT_CONNECT
               || ret == SSL_HANDSHAKE_WANT_WRITE) {
      vc->read.triggered = 0;
      nh->read_ready_list.remove(vc);
      vc->write.triggered = 0;
      nh->write_ready_list.remove(vc);
      if (ret == SSL_HANDSHAKE_WANT_READ || ret == SSL_HANDSHAKE_WANT_ACCEPT)
        read_reschedule(nh, vc);
      else
        write_reschedule(nh, vc);
    }
{code}

Seems odd to be clearing and remove read events if the real event was only a 
write.  And visa versa, seems odd to be clearing and removing write events if 
the real event was a read.

It seems to me that the sequence should be replaced with something like

{code}
if (ret == SSL_HANDSHAKE_WANT_READ || ret == SSL_HANDSHAKE_WANT_ACCEPT) {
      vc->read.triggered = 0;
      nh->read_ready_list.remove(vc);
      read_reschedule(nh, vc);
    } else if (ret == SSL_HANDSHAKE_WANT_CONNECT || ret == 
SSL_HANDSHAKE_WANT_WRITE) {
      vc->write.triggered = 0;
      nh->write_ready_list.remove(vc);
      write_reschedule(nh, vc);
    }
{code}

Looking back at the history shows adding and removing and re-adding of 
reschedules.  

* TS-3006 9/22/14 by me.  Adds in the read_reschedule case

* TS-2815 5/16/14 by [~bcall] Removes the read_reschedule case

* TS-2211 10/28/13 by postwait Adds read_reschedule and protects the 
write_reschedule and read_reschedule with specific event checks.

* TS-1921 5/17/13 by [~jpe...@apache.org] Adds in the write_reschedule

This seems like an obvious tidy up thing.  I'm not addressing a specific issue 
here, but the current thing seems wrong.  Given the history, I'm hesitant to 
clean things up without review from those that came before.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to