When we're enabling a server again (unix CLI or stats interface), we must not mark
it completely up because it can take a while before a failure is detected. So we
mark it one step above failure, which means it's up but will be marked down upon
first failure.
(cherry picked from commit 83c3e06452457ed5660fc814cbda5bf878bf19a2)
The stats web interface must be read-only by default to prevent security
holes. As it is now allowed to enable/disable servers, a new keyword
"stats admin" is introduced to activate this admin level, conditioned by ACLs.
(cherry picked from commit 5334bab92ca7debe36df69983c19c21b6dc63f78)
Based on a patch provided by Judd Montgomery, it is now possible to
enable/disable servers from the stats web interface. This allows to select
several servers in a backend and apply the action to them at the same time.
Currently, there are 2 known limitations :
- The POST data are limited to one packet
(don't alter too many servers at a time).
- Expect: 100-continue is not supported.
(cherry picked from commit 7693948766cb5647ac03b48e782cfee2b1f14491)
If a maxidle or maxlife parameter is set on the persistence cookie in
insert mode and the client did not provide a recent enough cookie,
then we emit a new cookie with a new last_seen date and the same
first_seen (if maxlife is set). Recent enough here designates a
cookie that would be rounded to the same date. That way, we can
refresh a cookie when required without doing it in all responses.
If the request did not contain such parameters, they are set anyway.
This means that a monitoring request that is forced to a server will
get an expiration date anyway, but this should not be a problem given
that the client is able to set its cookie in this case. This also
permits to force an expiration date on visitors who previously did
not have one.
If a request comes with a dated cookie while no date check is performed,
then a new cookie is emitted with no date, so that we don't risk dropping
the user too fast due to a very old date when we re-enable the date check.
All requests that were targetting the correct server and which had their
expiration date added/updated/removed in the response cookie are logged
with the 'U' ("updated") flag instead of the 'I' ("inserted"). So very
often we'll see "VU" instead of "VN".
(cherry picked from commit 8b3c6ecab6d37be5f3655bc3a2d2c0f9f37325eb)
If a cookie comes in with a first or last date, and they are configured on
the backend, they're checked. If a date is expired or too far in the future,
then the cookie is ignored and the specific reason appears in the cookie
field of the logs.
(cherry picked from commit faa3019107eabe6b3ab76ffec9754f2f31aa24c6)
The set-cookie status flags were not very handy and limited. Reorder
them to save some room for additional values and add the "U" flags
(for Updated expiration date) that will be used with expirable cookies
in insert mode.
(cherry picked from commit 5bab52f821bb0fa99fc48ad1b400769e66196ece)
In all cookie persistence modes but prefix, we now support cookies whose
value is suffixed with some contents after a vertical bar ('|'). This will
be used to pass an optional expiration date. So as of now we only consider
the part of the cookie value which is used before the vertical bar.
(cherry picked from commit a4486bf4e5b03b5a980d03fef799f6407b2c992d)
Some configs may involve httpclose in a frontend and http-pretend-keepalive
in a backend. httpclose used to take priority over keepalive, thus voiding
its effect. This change ensures that when both are combined, keepalive is
still announced to the server while close is announced to the client.
(cherry picked from commit 2be7ec90fa9caf66294f446423bbab2d00db9004)
Some broken browsers still happen to send a CRLF after a POST. Those which
send a CRLF in a second packet have it queued into the system's buffers,
which causes an RST to be emitted by some systems upon close of the response
(eg: Linux). The client may then receive the RST without the last response
segments, resulting in a truncated response.
This change leaves request polling enabled on a POST so that we can flush
any late data from the request buffers.
A more complete workaround would consist in reading from the request for a
long time, until we get confirmation that the close has been ACKed. This
is much more complex and should only be studied for newer versions.
(cherry picked from commit 12e316af4f0245fde12dbc224ebe33c8fea806b2)
This patch addresses exactly the same issues as the previous one, but
for responses this time. It also introduces implicit support for the
Set-Cookie2 header, for which there's almost nothing specific to do
since it is a clean header. This one allows multiple cookies in a
same header, by respecting the HTTP messaging semantics.
The new parser has been tested with insertion, rewrite, passive,
removal, prefixing and captures, and it looks OK. It's still able
to rewrite (or delete) multiple cookies at once. Just as with the
request parser, it tries hard to fix formating of the cookies it
displaces.
This patch too should be backported to 1.4 and possibly to 1.3.
The request cookie parser did not allow spaces to appear in cookie
values nor around the equal sign. The various RFCs on the subject
say different things, some suggesting that a space is allowed after
the equal sign and being worded in a way that lets one believe it
is allowed before too. Some spaces may appear inside values and be
part of the values. The quotes allow delimiters to be embedded in
values. The spaces before and after attributes should be trimmed.
The new parser addresses all those points and has been carefully tested.
It fixes misplaced spaces around equal signs before processing the cookies
or forwarding them. It also tries its best to perform clean removals by
always keeping the delimiter after the value being removed and leaving one
space after it.
The variable inside the parser have been renamed to make the code a lot
more understandable, and one multi-function pointer has been eliminated.
Since this patch fixes real possible issues, it should be backported to 1.4
and possibly 1.3, since one (single) case of wrong spaces has been reported
in 1.3.
The code handling the Set-Cookie has not been touched yet.
The header parser has a bug which causes commas to be matched within
quotes while it was not expected. The way the code was written could
make one think it was OK. The resulting effect is that the following
config would use the second IP address instead of the third when facing
this request :
source 0.0.0.0 usesrc hdr_ip(X-Forwarded-For,2)
GET / HTTP/1.0
X-Forwarded-for: "127.0.0.1, 127.0.0.2", 127.0.0.3
This fix must be backported to 1.4 and 1.3.
Fix 4fe4190278 was a bit too strong. It
has caused some chunked-encoded responses to be truncated when a recv()
call could return multiple chunks followed by a close. The reason is
that when a chunk is parsed, only its contents are scheduled to be
forwarded. Thus, the reader sees auto_close+shutr and sets shutw_now.
The sender in turn sends the last scheduled data and does shutw().
Another nasty effect is that it has reduced the keep-alive rate. If
a response did not completely fit into the buffer, then the auto_close
bit was left on and the sender would close upon completion.
The fix consists in not making use of auto_close when chunked encoding
is used nor when keep-alive is used, which makes sense. However it is
maintained on error processing.
Thanks to Cyril Bonté for reporting the issue early.
While it's usually desired to wait for a server response even
when the client closes its request channel, it can be problematic
with long polling requests. In order to let the server decide what
to do in such a case, if option abortonclose is set, we simply
forward the shutdown to the server. That way, it can decide to
take the appropriate action. Most servers will still process the
request, while some will probably want to abort.
Obviously, this only works as long as the client has not sent
another pipelined request over the same connection.
(was commit 0e25d86da49827ff6aa3c94132c01292b5ba4854 in 1.4)
Having a single tracking pointer for both frontend and backend counters
does not work. Instead let's have one for each. The keyword has changed
to "track-be-counters" and "track-fe-counters", and the ACL "trk_*"
changed to "trkfe_*" and "trkbe_*".
This patch adds support for the following session counters :
- http_req_cnt : HTTP request count
- http_req_rate: HTTP request rate
- http_err_cnt : HTTP request error count
- http_err_rate: HTTP request error rate
The equivalent ACLs have been added to check the tracked counters
for the current session or the counters of the current source.
When resetting a session's request analysers, we must take them from the
listener, not from the frontend. At the moment there is no difference
but this might change.
Till now, the frontend relied on the backend's options for INDEPSTR,
while at the time of accept, the frontend and backend are the same.
So we now use the frontend's pointer instead of the backend and we
don't have any dependency on the backend anymore in the frontend's
accept code.
The conn_retries attribute is now assigned when switching from SI_ST_INI
to SI_ST_REQ. This eliminates one of the last dependencies on the backend
in the frontend's accept() function.
The conn_retries still lies in the session and its initialization depends
on the backend when it may not yet be known. Let's first move it to the
stream interface.
It was particularly embarrassing that the server timeout was assigned
to buffers during an accept() just to be potentially changed later in
case of a use_backend rule. The frontend side has nothing to do with
server timeouts.
Now we initialize them right after the connect() succeeds. Later this
should change for a unique stream-interface timeout setting only.
The connection timeout stored in the buffer has not been used since the
stream interface were introduced. Let's get rid of it as it's one of the
things that complicate factoring of the accept() functions.
The 'client.c' file now only contained frontend-specific functions,
so it has naturally be renamed 'frontend.c'. Same for client.h. This
has also been an opportunity to remove some cross references from
files that should not have depended on it.
In the end, this file should contain a protocol-agnostic accept()
code, which would initialize a session, task, etc... based on an
accept() from a lower layer. Right now there are still references
to TCP.
By using msg->sol as the beginning of a message, wrong messages were
displayed in debug mode when they were truncated on the last line,
because msg->sol points to the beginning of the last line. Use
data+msg->som instead.
This would only be wrong when the server has not completely responded yet.
Fix two other occurrences of wrong rsp<->sl associations which were harmless
but wrong anyway.
Latest BF_READ_ATTACHED fix has unveiled a nice issue with the way
HTTP requests and responses are forwarded. The case where the request
aborts after the response has responded (POST with early response)
forgot to re-enable auto-close on the response. In fact it still
worked thanks to a side effect as long as BF_READ_ATTACHED was there
to force the states to be resynced (and the flags). Since last fix,
the missing auto-close causes CLOSE_WAIT connections when the client
aborts too late during a data transfer.
The right fix consists in considering the situation where the client
experiences an error and to explicitly abort the transfer. There is
no need to wake the response analysers up for that since they'd have
no added value and the analysers flags are cleared. However for a
future usage, that might help (eg: stickiness, ...).
This fix should be backported to 1.4 if the previous one is backported
too. After all the non-reg tests, the risks to see a problem arise
without both patches seems low, and both patches touch sensible areas
of the code. So there's no hurry.
Both dispatch and http_proxy modes were broken since 1.4-dev5 when
the adjustment of server health based on response codes was introduced.
In fact, in these modes, s->srv == NULL. The result is a plain segfault.
It should have been noted critical, but the fact that it remained 6
months without being noticed indicates that almost nobody uses these
modes anymore. Also, the crash is immediate upon first request.
Further versions should not be affected anymore since it's planned to
have a dummy server instead of these annoying NULL pointers.
It is now possible to stick on an IP address found in a HTTP header. Right
now only the last occurrence of the header can be used, which is generally
enough for most uses. Also, the header extraction rule only knows how to
convert the header to IP. Later it will be usable as a plain string with
an implicit conversion, and the syntax will not change.
Networks patterns loaded from files for longest match ACL testing
will now be arranged into a prefix tree. This is possible thanks to
the new prefix features in ebtree v6.0. Longest match testing is
slightly slower than exact data maching. However, the measured impact
of running at 42000 requests per second and testing whether the IP
address found in a header belongs to a list of 52000 networks or
not is 3% CPU (increase from 66% to 69%). This is low enough to
permit true geolocation based on huge tables.
Now if some ACL patterns are loaded from a file and the operation is
an exact string match, the data will be arranged in a tree, yielding
a significant performance boost on large data sets. Note that this
only works when case is sensitive.
A new dedicated function, acl_lookup_str(), has been created for this
matching. It is called for every possible input data to test and it
looks the tree up for the data. Since the keywords are loosely typed,
we would have had to add a new columns to all keywords to adjust the
function depending on the type. Instead, we just compare on the match
function. We call acl_lookup_str() when we could use acl_match_str().
The tree lookup is performed first, then the remaining patterns are
attempted if the tree returned nothing.
A quick test shows that when matching a header against a list of 52000
network names, haproxy uses 68% of one core on a core2-duo 3.2 GHz at
42000 requests per second, versus 66% without any rule, which means
only a 2% CPU increase for 52000 rules. Doing the same test without
the tree leads to 100% CPU at 6900 requests/s. Also it was possible
to run the same test at full speed with about 50 sets of 52000 rules
without any measurable performance drop.
When trying to display an invalid request or response we received,
we must at least check that we have identified something looking
like a start of message, otherwise we can dereference a NULL pointer.
This is used to disable persistence depending on some conditions (for
example using an ACL matching static files or a specific User-Agent).
You can see it as a complement to "force-persist".
In the configuration file, the force-persist/ignore-persist declaration
order define the rules priority.
Used with the "appsesion" keyword, it can also help reducing memory usage,
as the session won't be hashed the persistence is ignored.
I met a strange behaviour with appsession.
I firstly thought this was a regression due to one of my previous patch
but after testing with a 1.3.15.12 version, I also could reproduce it.
To illustrate, the configuration contains :
appsession PHPSESSID len 32 timeout 1h
Then I call a short PHP script containing :
setcookie("P", "should not match")
When calling this script thru haproxy, the cookie "P" matches the appsession rule :
Dumping hashtable 0x11f05c8
table[1572]: should+not+match
Shouldn't it be ignored ?
If you confirm, I'll send a patch for 1.3 and 1.4 branches to check that the
cookie length is equal to the appsession name length.
This is due to the comparison length, where the cookie length is took into
account instead of the appsession name length. Using the appsession name
length would allow ASPSESSIONIDXXX (+ check that memcmp won't go after the
buffer size).
Also, while testing, I noticed that HEAD requests where not available for
URIs containing the appsession parameter. 1.4.3 patch fixes an horrible
segfault I missed in a previous patch when appsession is not in the
configuration and HAProxy is compiled with DEBUG_HASH.
Some servers do not completely conform with RFC2616 requirements for
keep-alive when they receive a request with "Connection: close". More
specifically, they don't bother using chunked encoding, so the client
never knows whether the response is complete or not. One immediately
visible effect is that haproxy cannot maintain client connections alive.
The second issue is that truncated responses may be cached on clients
in case of network error or timeout.
Óscar Frías Barranco reported this issue on Tomcat 6.0.20, and
Patrik Nilsson with Jetty 6.1.21.
Cyril Bonté proposed this smart idea of pretending we run keep-alive
with the server and closing it at the last moment as is already done
with option forceclose. The advantage is that we only change one
emitted header but not the overall behaviour.
Since some servers such as nginx are able to close the connection
very quickly and save network packets when they're aware of the
close negociation in advance, we don't enable this behaviour by
default.
"option http-pretend-keepalive" will have to be used for that, in
conjunction with "option http-server-close".
Using get_ip_from_hdr2() we can look for occurrence #X or #-X and
extract the IP it contains. This is typically designed for use with
the X-Forwarded-For header.
Using "usesrc hdr_ip(name,occ)", it becomes possible to use the IP address
found in <name>, and possibly specify occurrence number <occ>, as the
source to connect to a server. This is possible both in a server and in
a backend's source statement. This is typically used to use the source
IP previously set by a upstream proxy.
Bernhard Krieger reported truncated HTTP responses in presence of some
specific chunk-encoded data, and kindly offered complete traces of the
issue which made it easy to reproduce it.
Those traces showed that the chunks were of exactly 8192 bytes, chunk
size and CRLF included, which was exactly half the size of the buffer.
In this situation, the function http_chunk_skip_crlf() could erroneously
try to parse a CRLF after the chunk believing there were more data
pending, because the number of bytes present in the buffer was considered
instead of the number of remaining bytes to be parsed.
Those two codes can be triggered on demand by client requests.
We must not fail a server on them.
Ideally we should ignore a certain amount of status codes which do
not indicate life nor death.
Hi Willy,
Please find a small patch to prevent haproxy segfaulting when logging captured headers in CLF format.
Example config to reproduce the bug :
listen test :10080
log 127.0.0.1 local7 debug err
mode http
option httplog clf
capture request header NonExistantHeader len 16
--
Cyril Bonté
In case of pipelined requests, if the client aborts before reading response
N-1, haproxy waits forever for the data to leave the buffer before parsing
the next response.
Often we need to understand why some transfers were aborted or what
constitutes server response errors. With those two counters, it is
now possible to detect an unexpected transfer abort during a data
phase (eg: too short HTTP response), and to know what part of the
server response errors may in fact be assigned to aborted transfers.
A copy-paste typo and a missing check were causing the logs to
report "PR" instead of "SD" when a server closes before sending
full data. Also, the log would erroneously report 502 while in
fact the correct response will already have been transmitted.
The bounce realign function was algorithmically good but as expected
it was not cache-friendly. Using it with large requests caused so many
cache thrashing that the function itself could drain 70% of the total
CPU time for only 0.5% of the calls !
Revert back to a standard memcpy() using a specially allocated swap
buffer. We're now back to 2M req/s on pipelined requests.
It is wrong to merge FE and BE stats for a proxy because when we consult a
BE's stats, it reflects the FE's stats eventhough the BE has received no
traffic. The most common example happens with listen instances, where the
backend gets credited for all the trafic even when a use_backend rule makes
use of another backend.
The trash buffer may now be smaller than a buffer because we can tune
it at run time. This causes a risk when we're trying to use it as a
temporary buffer to realign unaligned requests, because we may have to
put up to a full buffer into it.
Instead of doing a double copy, we're now relying on an open-coded
bouncing copy algorithm. The principle is that we move one byte at
a time to its final place, and if that place also holds a byte, then
we move it too, and so on. We finish when we've moved all the buffer.
It limits the number of memory accesses, but since it proceeds one
byte at a time and with random walk, it's not cache friendly and
should be slower than a double copy. However, it's only used in
extreme situations and the difference will not be noticeable.
It has been extensively tested and works reliably.
The fix below was incomplete :
commit d5fd51c75b
[BUG] http_server_error() must not purge a previous pending response
This can cause parts of responses to be truncated in case of
pipelined requests if the second request generates an error
before the first request is completely flushed.
Pending response data being rejected was still sent, causing inappropriate
error responses in case of error while parsing a response header. We must
purge pending data from the response buffer that were not scheduled to be
sent (l - send_max).
Now we establish the tunnel only once the status 200 reponse is
received. That way we can still support an authentication request
in response to a CONNECT, then a client's authentication response.
A 101 response is accompanied with an Upgrade header indicating
a new protocol that is spoken on the connection after the exchange
completes. At least we should switch to tunnel mode after such a
response.
I'm not sure if the fix is correct:
- if (req_acl->cond)
- ret = acl_exec_cond(req_acl->cond, px, s, txn, ACL_DIR_REQ);
+ if (!req_acl->cond)
+ continue;
Doesn't it ignore rules with no condition attached? I think that the
proper solution would be the following.
One check was missing for the 'polarity' of the test. Now 'unless'
works. BTW, 'unless' provides a nice way to perform one-line auth :
acl valid-user http_auth(user-list)
http-request auth unless valid-user
We're already able to know if a request is a proxy request or a
normal one, and we have an option "http-use-proxy-header" which states
that proxy headers must be checked. So let's switch to use the proxy
authentication headers and responses when this option is set and we're
facing a proxy request. That allows haproxy to enforce auth in front
of a proxy.
Support the new syntax (http-request allow/deny/auth) in
http stats.
Now it is possible to use the same syntax is the same like in
the frontend/backend http-request access control:
acl src_nagios src 192.168.66.66
acl stats_auth_ok http_auth(L1)
stats http-request allow if src_nagios
stats http-request allow if stats_auth_ok
stats http-request auth realm LB
The old syntax is still supported, but now it is emulated
via private acls and an aditional userlist.
Just as for the req* rules, we can now condition rsp* rules with ACLs.
ACLs match on response, so volatile request information cannot be used.
A warning is emitted if a configuration contains such an anomaly.
From now on, if request filters have ACLs defined, these ACLs will be
evaluated to condition the filter. This will be used to conditionally
remove/rewrite headers based on ACLs.
Krzysztof Oledzki suggested to disable keep-alive when a process
is going down due to a reload, in order to avoid ever-lasting
sessions. This is a simple and very efficient solution as it
ensures that at most one more request will be handled on a
keep-alive connection after the process has received a SIGUSR1
signal.
We must trim any excess data from the response buffer when recycling
a keep-alive connection, because we may have blocked an invalid response
from a server that we don't want to accidentely forward once we disable
the analysers, nor do we want those data to come along with next response.
A typical example of such data would be from a buggy server responding to
a HEAD with some data, or sending more than the advertised content-length.
For deciding to set the BF_EXPECT_MORE, we reused the same code as in
http_wait_for_request(), but here we must ignore buf->lr which is not
yet set and useless. This might only have caused random sub-optimal
behaviours.
Despite what is explicitly stated in HTTP specifications,
browsers still use the undocumented Proxy-Connection header
instead of the Connection header when they connect through
a proxy. As such, proxies generally implement support for
this stupid header name, breaking the standards and making
it harder to support keep-alive between clients and proxies.
Thus, we add a new "option http-use-proxy-header" to tell
haproxy that if it sees requests which look like proxy
requests, it should use the Proxy-Connection header instead
of the Connection header.
When using "option persist" or "force-persist", we want to know from the
logs if the cookie referenced a valid server or a down server. Till here
the flag reported a valid server even if the server was down, which is
misleading. Now we correctly report that the requested server was down.
We can typically see "--DI" when using "option persist" with redispatch,
ad "SCDN" when using force-persist on a down server.
This is used to force access to down servers for some requests. This
is useful when validating that a change on a server correctly works
before enabling the server again.
We use to delay the response if there is a new request in the buffer.
However, if the pending request is incomplete, we should not delay the
pending responses.
This can cause parts of responses to be truncated in case of
pipelined requests if the second request generates an error
before the first request is completely flushed.
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.
We need to improve Connection header handling in the request for it
to support the upcoming keep-alive mode. Now we have two flags which
keep in the session the information about the presence of a
Connection: close and a Connection: keep-alive headers in the initial
request, as well as two others which keep the current state of those
headers so that we don't have to parse them again. Knowing the initial
value is essential to know when the client asked for keep-alive while
we're forcing a close (eg in server-close mode). Also the Connection
request parser is now able to automatically remove single header values
at the same time they are parsed. This provides greater flexibility and
reliability.
All combinations of listen/front/back in all modes and with both
1.0 and 1.1 have been tested.
Calling this function after http_find_header2() automatically deletes
the current value of the header, and removes the header itself if the
value is the only one. The context is automatically adjusted for a
next call to http_find_header2() to return the next header. No other
change nor test should be made on the transient context though.
The close mode of a transaction would be switched to tunnel mode
at the end of the processing, letting a lot of pending data pass
in the other direction if any. Let's fix that by checking for the
close mode during state resync too.
We must set the error flags when detecting that a client has reset
a connection or timed out while waiting for a new request on a keep-alive
connection, otherwise process_session() sets it itself and counts one
request error.
That explains why some sites were showing an increase in request errors
with the keep-alive.
While waiting in a keep-alive state for a request, we want to silently
close if we don't get anything. However if we get a partial request it's
different because that means the client has started to send something.
This requires a new transaction flag. It will be used to implement a
distinct timeout for keep-alive and requests.
This change, suggested by Cyril Bonté, makes a lot of sense and
would have made it obvious that sessid was not properly initialized
while switching to keep-alive. The code is now cleaner.
The stream_int_cond_close() function was added to preserve the
contents of the response buffer because stream_int_retnclose()
was buggy. It flushed the response instead of flushing the
request. This caused issues with pipelined redirects followed
by error messages which ate the previous response.
This might even have caused object truncation on pipelined
requests followed by an error or by a server redirection.
Now that this is fixed, simply get rid of the now useless
function.
I've tried to follow all the pool_alloc2/pool_free2 calls in the code
to track memory leaks. I've found one which only happens when there's
already no more memory when allocating a new appsession cookie.
Sometimes it can be desired to return a location which is the same
as the request with a slash appended when there was not one in the
request. A typical use of this is for sending a 301 so that people
don't reference links without the trailing slash. The name of the
new option is "append-slash" and it can be used on "redirect"
statements in prefix mode.
When using server redirection, it is possible to specify a path
consisting of only one slash. While this is discouraged (risk of
loop) it may sometimes be useful combined with content switching.
The prefixing of a '/' then causes two slashes to be returned in
the response. So we now do as with the other redirects, don't
prepend a slash if it's alone.
Some message pointers were not usable once the message reached the
HTTP_MSG_DONE state. This is the case for ->som which points to the
body because it is needed to parse chunks. There is one case where
we need the beginning of the message : server redirect. We have to
call http_get_path() after the request has been parsed. So we rely
on ->sol without counting on ->som. In order to achieve this, we're
making ->rq.{u,v} relative to the beginning of the message instead
of the buffer. That simplifies the code and makes it cleaner.
Preliminary tests show this is OK.
This might have been introduced with chunk extensions. Note that
the server redirect still does not work because http_get_path()
cannot get the correct path once the request message is in the
HTTP_MSG_DONE state (->som does not point to the start of message
anymore).
If we accept a new request and that request produces an immediate
response (error, redirect, ...), then we may fail to send it in
case of pipelined requests if the response buffer is full. To avoid
this, we check the availability of at least maxrewrite bytes in the
response buffer before accepting a new pipelined request.
During a redirect, we used to send the last chunk of response with
stream_int_cond_close(). But this is wrong in case of pipeline,
because if the response already contains something, this function
will refrain from touching the buffer. Use a concatenation function
instead.
Also, this call might still fail when the buffer is full, we need
a second fix to refrain from parsing an HTTP request as long as the
response buffer is full, otherwise we may not even be able to return
a pending redirect or an error code.
That patch was incorrect because under some circumstances, the
capture memory could be freed by session_free() and then again
by http_end_txn(), causing a double free and an eventual segfault.
The pool use count was also reported wrong due to this bug.
The cleanup code was removed from session_free() to remain only
in http_end_txn().
Hank A. Paulson reported a massive memory leak when using keep-alive
mode. The information he provided made it easy to find that captured
request and response headers were erased but not released when renewing
a request.
Several HTTP analysers used to set those flags to values that
were useful but without considering the possibility that they
were not called again to clean what they did. First, replace
direct flag manipulation with more explicit macros. Second,
enforce a rule stating that any buffer which changes one of
these flags from the default must restore it after completion,
so that other analysers see correct flags.
With both this fix and the previous one about analyser bits,
we should not see any more stuck sessions.
Commit 0dfdf19b64 introduced a
regression because the connection header is now parsed and checked
depending on the configured options, but the options are set after
calling it instead of being set before.
Historically, "option httpclose" has always worked the same way. It
only mangles the "Connection" header in the request and the response
if needed, but does not affect the connection by itself, and ignores
any further data. It is dangerous to change this behaviour without
leaving any other alternative. If an active close is desired, it's
better to make use of "option forceclose" which does exactly what
it intends to do.
So as of now, "option httpclose" will only mangle the headers as
before, and will only affect the connection by itself when combined
with another connection-related option (eg: keepalive or server-close).
We basically have to mimmic the code of process_session() here, so
when the remote output is closed, we must abort otherwise we'll end
up with data which cannot leave the buffer.
By default this function returned 0 indicating an end of analysis.
This was not a problem as long as it was the last analyser in the
chain but becomes quite a big one now since it skips the forwarder
with auto_close enabled, causing some data to pass under the nose
of the last one undetected.
