Now, http_parse_chunk_size and http_skip_chunk_crlf return the number of bytes
parsed on success. http_skip_chunk_crlf does not use msg->sol anymore.
On the other hand, http_forward_trailers is unchanged. It returns >0 if the end
of trailers is reached and 0 if not. In all cases (except if an error is
encountered), msg->sol contains the length of the last parsed part of the
trailer headers.
Internal doc and comments about msg->sol has been updated accordingly.
This file was recovered from the first project where it was born 12 years
ago, but it's still convenient to understand how our circular lists work,
so let's add it.
This was the first transparent proxy technology supported by haproxy
circa 2005 but it was obsoleted in 2007 by Tproxy 4.0 which removed a
lot of the earlier versions' shortcomings and was finally merged into
the kernel. Since nobody has been using cttproxy for many years now
and nobody has even just tried to compile the files, it's time to
remove it. The doc was updated as well.
Daniel Dubovik reported an interesting bug showing that the request body
processing was still not 100% fixed. If a POST request contained short
enough data to be forwarded at once before trying to establish the
connection to the server, we had no way to correctly rewind the body.
The first visible case is that balancing on a header does not always work
on such POST requests since the header cannot be found. But there are even
nastier implications which are that http-send-name-header would apply to
the wrong location and possibly even affect part of the request's body
due to an incorrect rewinding.
There are two options to fix the problem :
- first one is to force the HTTP_MSG_F_WAIT_CONN flag on all hash-based
balancing algorithms and http-send-name-header, but there's always a
risk that any new algorithm forgets to set it ;
- the second option is to account for the amount of skipped data before
the connection establishes so that we always know the position of the
request's body relative to the buffer's origin.
The second option is much more reliable and fits very well in the spirit
of the past changes to fix forwarding. Indeed, at the moment we have
msg->sov which points to the start of the body before headers are forwarded
and which equals zero afterwards (so it still points to the start of the
body before forwarding data). A minor change consists in always making it
point to the start of the body even after data have been forwarded. It means
that it can get a negative value (so we need to change its type to signed)..
In order to avoid wrapping, we only do this as long as the other side of
the buffer is not connected yet.
Doing this definitely fixes the issues above for the requests. Since the
response cannot be rewound we don't need to perform any change there.
This bug was introduced/remained unfixed in 1.5-dev23 so the fix must be
backported to 1.5.
These ones were design notes and ideas collected during the 1.5
development phase lying on my development machine. There might still
be some value in keeping them for future reference since they mention
certain corner cases.
Summary:
Added a document for hashing under internal docs explaining
hashing in haproxy along with the results of tests under the test
folder.
These documents together explain the motivation for adding
options for hashing algorithms with the option of enabling or
disabling of avalanche.
Also add some thoughts about the existing and new design.
Note: an earlier design used the names "head" and "tail" for both sides
of the buffer, but it appears awkward as these words may be understood
in two forms (feed by head, output by tail, or make the newcomers wait
at the tail of the queue). Also there were already a few functions in the
code making use of either terminology. So better avoid this terminology
and use "input" and "output" instead.
This one is the next step of previous patch. It correctly computes
the response mode and the Connection flag transformations depending
on the request mode and version, and the response version and headers.
We're now also able to add "Connection: keep-alive", and to convert
server's close during a keep-alive connection to a server-close
connection.
The connection header is complex to handle, especially in the response
path, depending on request and response HTTP versions, desired mode,
etc... Let's document it. Note that only a subset of this document is
currently implemented.
An abort during a connect would go to the SI_ST_CLO state without
the buffers shut. This was causing some sessions to never end if
they would abort before the connect request was initiated. This
bug has been introduced after 1.4-dev2.
The doc has been extended to reflect that too.
There were rare situations where it was not easy to detect that a failed
session attempt had occurred and needed some server cleanup. In particular,
client aborts sometimes lead to session leaks on the server side.
A new state "SI_ST_DIS" (disconnected) has been introduced for this. When
a session has been closed at a stream interface but the server cleanup has
not occurred, this state is entered instead of CLO. The cleanup is then
performed there and the state goes to CLO.
A new diagram has been added to show possible stream_interface state
transitions that can occur in a stream-sock. It makes debugging easier.
Since the introduction of speculative I/O, it was not always possible
to correctly detect a connection establishment. Particularly, in TCP
mode, there is no data to send and getsockopt() returns no error. The
solution consists in trying a connect() again to get its diagnostic.
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
