BUG: http: disable TCP delayed ACKs when forwarding content-length data

Commits 5c6209 and 072930 were aimed at avoiding undesirable PUSH flags
when forwarding chunked data, but had the undesired effect of causing
data advertised by content-length to be affected by the delayed ACK too.
This can happen when the data to be forwarded are small enough to fit into
a single send() call, otherwise the BF_EXPECT_MORE flag would be removed.

Content-length data don't need the BF_EXPECT_MORE flag since the low-level
forwarder already knows it can safely rely on bf->to_forward to set the
appropriate TCP flags.

Note that the issue is only observed in requests at the moment, though the
later introduction of server-side keep-alive could trigger the issue on the
response path too.

Special thanks to Randy Shults for reporting this issue with a lot of
details helping to reproduce it.

The fix must be backported to 1.4.
BUG: checks: fix server maintenance exit sequence

Recent commit 62c3be broke maintenance mode by fixing srv_is_usable().
Enabling a disabled server would not re-introduce it into the farm.
The reason is that in set_server_up(), the SRV_MAINTAIN flag is still
present when recounting the servers. The flag was removed late only to
adjust a log message. Keep a copy of the old flag instead and update
SRV_MAINTAIN earlier.

This fix must also be backported to 1.4 (but no release got the regression).
BUG/MINOR: stream_sock: don't remove BF_EXPECT_MORE and BF_SEND_DONTWAIT on partial writes

The flags are one-shot but should be maintained over all send() operations
as long as send_max is not flushed. The flags were incidentely cleared once
a complete send() was performed, regardless of the fact that the send()
might have been on the first half of a buffer before a wrapping. The result
is that on wrapping data (eg: which happens often with chunked encoding),
many incomplete segments are transmitted instead of being aggregated.

The fix consists in only flushing the flags only once send_max is empty,
which was the expected behaviour.

This fix should be backported to 1.4 though it is not critical, just sub-optimal.
DOC: enumerate valid status codes for "observe layer7"
MINOR: buffer: switch a number of buffer args to const

A number of offset computation functions use struct buffer* arguments
and return integers without modifying the input. Using consts helps
simplifying some operations in callers.
CLEANUP: silence signedness warning in acl.c

The recent SNI patch introduced a trivial warning in acl.c.
BUG: stream_sock: si->release was not called upon shutw()

The ->release function of the stream interface is never called upon
a shutw() because it's placed after a return statement. It is possible
that it has impacted inter-process stick-table replication by preventing
a full resync after certain sequences of connection breakage. Since this
bug has been present since the introduction of the ->release() callback,
it cannot have caused regressions, just possibly non-working situations.

This was detected at Exceliance by Emeric Brun during a code review. It
is 1.5-specific.
MEDIUM: log: use log_format for mode tcplog

Merge http_sess_log() and tcp_sess_log() to sess_log() and move it to
log.c

A new field in logformat_type define if you can use a logformat
variable in TCP or HTTP mode.

doc: log-format in tcp mode

Note that due to the way log buffer allocation currently works, trying to
log an HTTP request without "option httplog" is still not possible. This
will change in the near future.
MEDIUM: log-format: backend source address %Bi %Bp

%Bi return the backend source IP
%Bp return the backend source port

Add a function pointer in logformat_type to do additional configuration
during the log-format variable parsing.
BUG/MINOR: log-format: fix %o flag

The %o flag was not working at all.
MINOR: log: use "%ts" to log term status only and "%tsc" to log with cookie

The difference could be seen when logging a request in HTTP mode with option
tcplog, as it would keep emitting 4 chars. Better use two distinct flags to
clear the confusion.
BUG/CRITICAL: log: fix risk of crash in development snapshot

Commit a1cc38 introduced a regression which was easy to trigger till ad4cd58
(snapshots 20120222 to 20120311 included). The bug was still present after
that but harder to trigger.

The bug is caused by the use of two distinct log buffers due to intermediary
changes. The issue happens when an HTTP request is logged just after a TCP
request during the same second and the HTTP request is too large for the buffer.
In this case, it happens that the HTTP request is logged into the TCP buffer
instead and that length controls can't detect anything.

Starting with bddd4f, the issue is still possible when logging too large an
HTTP request just after a send_log() call (typically a server status change).

We owe a big thanks to Sander Klein for testing several snapshots and more
specifically for taking significant risks in production by letting the buggy
version crash several times in order to provide an exploitable core ! The bug
could not have been found without this precious help. Thank you Sander !

This fix does not need to be backported, it did not affect any released version.
BUG/MEDIUM: bad length in log_format and __send_log

__send_log(): the size of the buffer sent is wrong when the facility
is lower than 3 digits.

logformat_write_string(): computation of size is wrong

Note: this was introduced after 1.5-dev7, no backport needed.
MINOR: patch for minor typo (ressources/resources)

The main stats page says "ressources" (French spelling) rather than
"resources" (English spelling).

One little patch attached (against v1.4.20).

Many thanks,

Adrian
MINOR: logformat %st is signed

replace ultoa by ltoa for HTTP status code (can be -1)
BUG/MAJOR: possible crash when using capture headers on TCP frontends

Olufemi Omojola provided a config and a core showing a possible crash
when captures are configured on a TCP-mode frontend which branches to
an HTTP backend. The reason is that being in TCP mode, the frontend
does not allocate capture pools for the request, but the HTTP backend
tries to use them and dies on the NULL.

While such a config has long been unlikely to happen, it looks like
people using websocket tend to do this more often now.

Change the control to use the pointer instead of the number of captures
to know when to log.

This bug was reported in 1.4.20, so it must be backported there.
MINOR: config: disable header captures in TCP mode and complain

In order to help users fix their configs, report a warning when a capture
has been set on a non-HTTP frontend.

This should be backported to 1.4.
CLEANUP: Make check_statuses, analyze_statuses and process_chk static

These symbols are only used inside src/checks.c
CLEANUP: Fix HCHK spelling errors
[RELEASE] Released version 1.5-dev8

Released version 1.5-dev8 with the following main changes :
    - MINOR: patch for minor typo (ressources/resources)
    - MEDIUM: http: add support for sending the server's name in the outgoing request
    - DOC: mention that default checks are TCP connections
    - BUG/MINOR: fix options forwardfor if-none when an alternative header name is specified
    - CLEANUP: Make check_statuses, analyze_statuses and process_chk static
    - CLEANUP: Fix HCHK spelling errors
    - BUG/MINOR: fix typo in processing of http-send-name-header
    - MEDIUM: log: Use linked lists for loggers
    - BUILD: fix declaration inside a scope block
    - REORG: log: split send_log function
    - MINOR: config: Parse the string of the log-format config keyword
    - MINOR: add ultoa, ulltoa, ltoa, lltoa implementations
    - MINOR: Date and time fonctions that don't use snprintf
    - MEDIUM: log: make http_sess_log use log_format
    - DOC: log-format documentation
    - MEDIUM: log: use log_format for mode tcplog
    - MEDIUM: log-format: backend source address %Bi %Bp
    - BUG/MINOR: log-format: fix %o flag
    - BUG/MEDIUM: bad length in log_format and __send_log
    - MINOR: logformat %st is signed
    - BUILD/MINOR: fix the source URL in the spec file
    - DOC: acl is http_first_req, not http_req_first
    - BUG/MEDIUM: don't trim last spaces from headers consisting only of spaces
    - MINOR: acl: add new matches for header/path/url length
    - BUILD: halog: make halog build on solaris
    - BUG/MINOR: don't use a wrong port when connecting to a server with mapped ports
    - MINOR: remove the client/server side distinction in SI addresses
    - MINOR: halog: add support for matching queued requests
    - DOC: indicate that cookie "prefix" and "indirect" should not be mixed
    - OPTIM/MINOR: move struct sockaddr_storage to the tail of structs
    - OPTIM/MINOR: make it possible to change pipe size (tune.pipesize)
    - BUILD/MINOR: silent a build warning in src/pipe.c (fcntl)
    - OPTIM/MINOR: move the hdr_idx pools out of the proxy struct
    - MEDIUM: tune.http.maxhdr makes it possible to configure the maximum number of HTTP headers
    - BUG/MINOR: fix a segfault when parsing a config with undeclared peers
    - CLEANUP: rename possibly confusing struct field "tracked"
    - BUG/MEDIUM: checks: fix slowstart behaviour when server tracking is in use
    - MINOR: config: tolerate server "cookie" setting in non-HTTP mode
    - MEDIUM: buffers: add some new primitives and rework existing ones
    - BUG: buffers: don't return a negative value on buffer_total_space_res()
    - MINOR: buffers: make buffer_pointer() support negative pointers too
    - CLEANUP: kill buffer_replace() and use an inline instead
    - BUG: tcp: option nolinger does not work on backends
    - CLEANUP: ebtree: remove a few annoying signedness warnings
    - CLEANUP: ebtree: clarify licence and update to 6.0.6
    - CLEANUP: ebtree: remove 4-year old harmless typo in duplicates insertion code
    - CLEANUP: ebtree: remove another typo, a wrong initialization in insertion code
    - BUG: ebtree: ebst_lookup() could return the wrong entry
    - OPTIM: stream_sock: reduce the amount of in-flight spliced data
    - OPTIM: stream_sock: save a failed recv syscall when splice returns EAGAIN
    - MINOR: acl: add support for TLS server name matching using SNI
    - BUG: http: re-enable TCP quick-ack upon incomplete HTTP requests
    - BUG: proto_tcp: don't try to bind to a foreign address if sin_family is unknown
    - MINOR: pattern: export the global temporary pattern
    - CLEANUP: patterns: get rid of pattern_data_setstring()
    - MEDIUM: acl: use temp_pattern to store fetched information in the "method" match
    - MINOR: acl: include pattern.h to make pattern migration more transparent
    - MEDIUM: pattern: change the pattern data integer from unsigned to signed
    - MEDIUM: acl: use temp_pattern to store any integer-type information
    - MEDIUM: acl: use temp_pattern to store any address-type information
    - CLEANUP: acl: integer part of acl_test is not used anymore
    - MEDIUM: acl: use temp_pattern to store any string-type information
    - CLEANUP: acl: remove last data fields from the acl_test struct
    - MEDIUM: http: replace get_ip_from_hdr2() with http_get_hdr()
    - MEDIUM: patterns: the hdr() pattern is now of type string
    - DOC: add minimal documentation on how ACLs work internally
    - DOC: add a coding-style file
    - OPTIM: halog: keep a fast path for the lines-count only
    - CLEANUP: silence a warning when building on sparc
    - BUG: http: tighten the list of allowed characters in a URI
    - MEDIUM: http: block non-ASCII characters in URIs by default
    - DOC: add some documentation from RFC3986 about URI format
    - BUG/MINOR: cli: correctly remove the whole table on "clear table"
    - BUG/MEDIUM: correctly disable servers tracking another disabled servers.
    - BUG/MEDIUM: zero-weight servers must not dequeue requests from the backend
    - MINOR: halog: add some help on the command line
    - BUILD: fix build error on FreeBSD
    - BUG: fix double free in peers config error path
    - MEDIUM: improve config check return codes
    - BUILD: make it possible to look for pcre in the default system paths
    - MINOR: config: emit a warning when 'default_backend' masks servers
    - MINOR: backend: rework the LC definition to support other connection-based algos
    - MEDIUM: backend: add the 'first' balancing algorithm
    - BUG: fix httplog trailing LF
    - MEDIUM: increase chunk-size limit to 2GB-1
    - BUG: queue: fix dequeueing sequence on HTTP keep-alive sessions
    - BUG: http: disable TCP delayed ACKs when forwarding content-length data
    - BUG: checks: fix server maintenance exit sequence
    - BUG/MINOR: stream_sock: don't remove BF_EXPECT_MORE and BF_SEND_DONTWAIT on partial writes
    - DOC: enumerate valid status codes for "observe layer7"
    - MINOR: buffer: switch a number of buffer args to const
    - CLEANUP: silence signedness warning in acl.c
    - BUG: stream_sock: si->release was not called upon shutw()
    - MINOR: log: use "%ts" to log term status only and "%tsc" to log with cookie
    - BUG/CRITICAL: log: fix risk of crash in development snapshot
    - BUG/MAJOR: possible crash when using capture headers on TCP frontends
    - MINOR: config: disable header captures in TCP mode and complain