tree 09f0653eeadc3b0f0ffd9a696c4f29d275bc4b49
parent 5af1fa1df0f367d9ce5557c93e0a229263618729
author Willy Tarreau <w@1wt.eu> 1280243712 +0200
committer Willy Tarreau <w@1wt.eu> 1281441868 +0200

[BUG] session: analysers must be checked when SI state changes

Since the BF_READ_ATTACHED bug was fixed, a new issue surfaced. When
a connection closes on the return path in tunnel mode while the request
input is already closed, the request analyser which is waiting for a
state change never gets woken up so it never closes the request output.
This causes stuck sessions to remain indefinitely.

One way to reliably reproduce the issue is the following (note that the
client expects a keep-alive but not the server) :

  server: printf "HTTP/1.0 303\r\n\r\n" | nc -lp8080
  client: printf "GET / HTTP/1.1\r\n\r\n" | nc 127.1 2500

The reason for the issue is that we don't wake the analysers up on
stream interface state changes. So the least intrusive and most reliable
thing to do is to consider stream interface state changes to call the
analysers.

We just need to remember what state each series of analysers have seen
and check for the differences. In practice, that works.

A later improvement later could consist in being able to let analysers
state what they're interested to monitor :
  - left SI's state
  - right SI's state
  - request buffer flags
  - response buffer flags

That could help having only one set of analysers and call them once
status changes.