Generally, if a recv() returns less bytes than the MSS, it means that
there is nothing left in the system's buffers, and that it's not worth
trying to read again because we are very likely to get nothing. A
default read low limit has been set to 1460 bytes below which we stop
reading.
This has brought a little speed boost on small objects while maintaining
the same speed on large objects.
Multiple read polling was temporarily disabled, which had the side
effect of burning huge amounts of CPU on large objects. It has now
been re-implemented with a limit of 8 calls per wake-up, which seems
to provide best results at least on Linux.
Very recent changes consisting in moving some pointers to the
transaction instead of the session have lead to a bug because
those pointers were only initialized if the protocol was HTTP,
but they were freed based on their value. In some cases, it
was possible to cause double frees.
HTTP header matching is now made easier with http_header_match2().
Various locations have been adapted to use it. A small bug was also
fixed causing empty headers to be matched till next one.
Two new functions http_header_add_tail() and http_header_add_tail2()
make it easier to append headers, and also reduce the number of
sprintf() calls and perform stricter checks.
Some session flags were clearly related to HTTP transactions.
A new 'flags' field has been added to http_txn, and the
associated flags moved to proto_http.h.
Now the response is correctly processed in the backend first
then in the frontend. It has followed intensive tests to
catch regressions, and everything seems OK now, but the code
is young anyway.
Both request and response captures will have to parse headers following
the same methods. It's better to factorize the code, hence the new
capture_headers() function.
Some parts of HTTP processing were incorrectly called "request" while
they are messages or transactions. The following structure members
have changed :
http_msg.hdr_state => msg_state
http_msg.sor => som
http_req.req_state => removed
http_req => http_txn
The new rbtree-based scheduler makes heavy use of tv_cmp2(), and
this function becomes a huge CPU eater. Refine it a little bit in
order to slightly reduce CPU usage.
If captures were configured in a TCP-only listener, and
the logs were enabled, the proxy could segfault when
trying to scan the capture buffer which was NULL. Such
an erroneous configuration will not be possible anymore
soon, but let's avoid the problem for now by detecting
the NULL condition.
- fix critical bug introduced with 1.3.6 : an empty request header
may lead to a crash due to missing pointer assignment
- hdr_idx might be left uninitialized in debug mode
- fixed build on FreeBSD due to missing fd_set declaration
A missing pointer assignment in case of an empty header
will result in this header's length being 65535, causing
a SEGV when accessing the next header. It should not be
possible to exploit this problem to run arbitrary code
because the crash occurs while reading the data.
When a request is invalid during RQ_BEFORE AND the debug mode is active,
the hdr_idx might be used uninitialized. Let's initialize it right after
the accept() for now.
Sorin Pop reported a patch to fix build on FreeBSD.
The file common/standard.h used an fd_set in a declaration
but did not include enough headers for it to be known.
Since the request is no longer part of the headers, cookies and
authentication did not work anymore. Obvious fix is to add the
request offset to the start pointer.
- stats now support the HEAD method too
- extracted http request from the session
- huge rework of the HTTP parser which is now a 28-state FSM.
- linux-style likely/unlikely macros for optimization hints
- do not create a server socket when there's no server
The HTTP parser has been rewritten for better compliance to RFC2616.
The same parser is now usable for both requests and responses, and
it now supports HTTP/0.9 as well as multi-line headers. It has also
been improved for speed ; a typicial HTTP request is parsed in about
2 microseconds on a 1 GHz processor.
The monitor-uri check has been moved so that the requests are not
logged. The httpclose option now tries to change as little as
possible in the request, and does not affect the first header if
it is already set to 'close'. HTTP/0.9 requests are converted to
HTTP/1.0 before being forwarded.
Headers and request transformations are now distinct. The headers
list is updated after each insertion/removal/transformation. The
request is re-parsed and checked after each transformation. It is
not possible anymore to remove a request, and requests which lead
to invalid request lines are now rejected.
Since the distinction of backends and frontends, it has become
possible that some requests reach a frontend which has no
backend parameters. We must not create a socket on the backend
side just to destroy it later in such a case. The real problem
comes from the dispatch mode not being explictly stated.
A struct http_req has been created to collect every information
related to an HTTP request being processed. Right now, it is
still in the struct session but the frontier is clear now.
There are browsers which sometimes send HEAD requests to the stats
page, but it was not handled so it returned a 503 server error or
was simply sent to the default backend servers.
Now with a HEAD request, the stats return the headers and finish
there. Normally, other methods should be blocked so that the stats
page really catches the whole URI. Other methods would need to cause
a 405 Method not allowed to be returned.
- added complete support and doc for TCP Splicing
- replaced the wait-queue linked list with an rbtree.
- stats: swap color sets for active and backup servers
- try to guess server check port when unset
- a few bugfixes and cleanups
When a server has no port specified and there is a check
enabled on it, the check is disabled because the port is
unknown. However, people expect the "listen" line to set
the check port just like it sets the server's port. Now,
if a port is specified in the listen or in the first bind
and nowhere else, it will be used for the checks as well.
This patch from Sin Yu makes use of an rbtree for the wait queue,
which will solve the slowdown problem encountered when timeouts
are heterogenous in the configuration. The next step will be to
turn maintain_proxies() into a per-proxy task so that we won't
have to scan them all after each poll() loop.
