tree 585f0747be2dbeae9d0ff15449e35081a55f8c94
parent 0558a02eb141a8f6d9e894834547cb64213e4ed4
author Willy Tarreau <w@1wt.eu> 1365353288 +0200
committer Willy Tarreau <w@1wt.eu> 1398201328 +0200
encoding latin1

MAJOR: http: do not use msg->sol while processing messages or forwarding data

There are still some pending issues in the gzip compressor, and fixing
them requires a better handling of intermediate parsing states.

Another issue to deal with is the rewinding of a buffer during a redispatch
when a load balancing algorithm involves L7 data because the exact amount of
data to rewind is not clear. At the moment, this is handled by unwinding all
pending data, which cannot work in responses due to pipelining.

Last, having a first analysis which parses the body and another one which
restarts from where the parsing was left is wrong. Right now it only works
because we never both parse and transform in the same direction. But that
is wrong anyway.

In order to address the first issue, we'll have to use msg->eoh + msg->eol
to find the end of headers, and we still need to store the information about
the forwarded header length somewhere (msg->sol might be reused for this).

msg->sov may only be used for the start of data and not for subsequent chunks
if possible. This first implies that we stop sharing it with header length,
and stop using msg->sol there. In fact we don't need it already as it is
always zero when reaching the HTTP_MSG_BODY state. It was only updated to
reflect a copy of msg->sov.

So now as a first step into that direction, this patch ensure that msg->sol
is never re-assigned after being set to zero and is not used anymore when
we're dealing with HTTP processing and forwarding. We'll later reuse it
differently but for now it's secured.

The patch does nothing magic, it only removes msg->sol everywhere it was
already zero and avoids setting it. In order to keep the sov-sol difference,
it now resets sov after forwarding data. In theory there's no problem here,
but the patch is still tagged major because that code is complex.