ocproxy updates (was: RFC: OpenConnect enhancements)

[Kevin Cernekee]

On Sun, Sep 30, 2012 at 11:42 PM, David Edmondson <dme at dme.org> wrote:
>> I am still concerned about memory usage, which keeps growing with each
>> connection.  Maybe the thread startup/teardown should work from a
>> fixed "pool" like Apache does; currently it is dynamic.
>
> Rather than have a pair of threads for each connection we could have a single thread for "reading from local sockets" and another for "reading from lwip connections" (the pair required due to the differing API).

After playing around a little more, I wound up dropping all of the
netconn_* API usage in favor of the raw TCP API.  This allowed me to
use an event loop executing from a single thread.  The memory
situation is much better now; only lwIP is using dynamic allocations.

Latency-wise it "feels" snappier, but I don't have any hard data to quantify it.

I also added a few other goodies:

 - IP autoconfiguration from the environment vars
 - Try to exit if OpenConnect has died (e.g. remote idle disconnects)
 - TCP keepalives, to prevent the remote idle disconnects
 - "-g" option (similar to ssh) to bind to INADDR_ANY
 - Minimal "getting started" documentation
 - SOCKS error replies

Unfortunately the code has diverged quite a bit, so it's your call
whether it's worth rolling back into the original ocproxy project.

Web: https://github.com/cernekee/ocproxy
Git: git://github.com/cernekee/ocproxy.git master

Kevin Cernekee (12):
      README: Correct pathname
      sys_arch: Fix compile error on gcc 4.7
      ocproxy: Set IP configuration from the environment, if possible
      Rewrite ocproxy.c to use the raw TCP API + libevent
      Remove unused files
      Add TCP keepalive
      scripts: Change capitalization of command line args
      Fix handling of connections reset by peer
      Terminate ocproxy when OpenConnect quits
      recv_cb: Return ERR_ABRT if the connection terminated
      Update README file with new instructions
      Require MTU to configure interface