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.
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.
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.
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.
The tcp-splicing code has been merged, and a doc has been written.
A configuration example has been derived from the previous content
switching sample.
Some options will need some checks (or initializations) to be performed
before starting everything. The cfg_opts table has been extended to
allow storing of options-dependant checks.
Since the introduction of hdr_idx, session_free() had not
been updated to free the header ! It implied a consumption
of about 400 bytes per new session.
The stats page could not tell the difference between a FE and a BE.
It has been revamped to indicate all relevant information. The font
is also slightly smaller in order for all the info to fit into small
screens. The data output path has been greatly simplified to use
string chunks.
Most common options are now stored in an array which eases
the parsing and which also permits reporting of ignored
options depending on the proxy's capabilities (back/front).
The "httpclose" option affects both frontend and backend, so it
was logical to check for its presence at both places. A request
which traverses either a frontend or a backend with this option
set will have a "Connection: close" header appended.
The log format has been slightly updated to separately report the name
of the frontend and the name of the backend. The accept date has been
enhanced to report the millisecond. The number of remaining connections
has also been updated and their order reversed, to include the number
of connections on the frontend. The new log format is now :
- $1: IP:port
- $2: accept date in this format : [dd/mm/YYYY:HH:MM:SS.ttt]
- $3: frontend name
- $4: backend name '/' server name
- $5: req time '/' queue time '/' conn time '/' header time '/' total time
- $6: HTTP status code
- $7: number of bytes returned
- $8: captures (request)
- $9: captures (response)
- $10: completion flags
- $11: remaining conns on process '/' frontend '/' backend '/' server
- $12: srv queue size '/' backend queue size
- $13..: '"' full request '"'
The notion of capabilities has been added to the proxy so that we
know whether a proxy supports frontend, backend, or rulesets. Given
this, some parameters are optionnal, some are ignored with a warning
and others are forbidden. It is now possible to write valid two level
configs without binding to dummy address/ports.
The maxconn argument is used only for the listeners, and the
fullconn is used only for the backends. If unset, it inherits
maxconn's value which itself can inherit the default or the
global value (we might need to change this).
To solve the logging maze, it has been decided that the frontend
and nothing else will define how a session will be logged. It might
change in the future but at least this choice allows all sort of
fantasies.
It is now possible to define an errorloc in the backend as well as
in the frontend. The backend's will be used first, and if undefined,
then the frontend's will be used instead. If none is used, then the
original error messages will be used.
HTTP error messages were all specific cases handled by an IF.
Now they are all in an array so that it will be easier to add
new ones. Also, the return functions now use chunks as inputs
so that it should be easier to provide alternative return
messages if needed.
Sin Yu's patch to permit to change the proxy from a regex was merged
with little changes :
- req_cap/rsp_cap are not reassigned to the new proxy, they stay
attached to the frontend
- the actions have been renamed "reqsetbe" and "reqisetbe" for
"set BackEnd".
- the buffer is not reset after the switch, instead, the headers are
parsed again by the backend
- in Sin's patch, it was theorically possible to switch multiple times,
but the switching track was lost, making it impossible to apply
server responsesin the reverse order. Now switching is limited to
1 action (separation between frontend and backend) but the filters
remain.
Now it will be extremely easy to add other switching conditions, such
as host matching, URI matching, etc...
There's still a hard work to be done on the logs and stats.
The logs have become a real mess. It is now very hard to tell which
frontend/backend will impose its configuration for the logs. This
needs a complete rework but at least it should work.
The nbconn attribute in the proxies was not relevant anymore because
a frontend A may use backend B and both of them must account for their
respective connections. For this reason, there now are two separate
counters for frontend and backend connections.
The stats page has been updated to reflect the backend, but a separate
line entry for the frontend with error counts would be good.
Note that as of now, beconn may be higher than maxconn, because maxconn
applies to the frontend, while beconn may be increased due to sessions
passed from another frontend.
There was a confusion about the way to find filters and backend
parameters from sessions. The chaining has been changed between
the session and the proxy.
Now, a session knows only two proxies : one frontend (->fe) and
one backend (->be). Each proxy has a link to the proxy providing
filters and to the proxy providing backend parameters (both self
by default).
The captures (cookies and headers) have been attached to the
frontend's filters for now.
The uri_auth and the statistics are attached to the backend's
filters so that the uri can depend on a hostname for instance.
A proxy will be able to borrow parameters from another one.
In particular, the filters will be inheritable from another
proxy, and the backend parameters too.
The check of uri_auth is now in a separate function which is
checked after every backend switch, so that it will be possible
to have an uri_auth for the frontend and another one for the
backend.
Some while() constructs are not very efficient with gcc, yet they are
used to scan all the text in the start line and the headers. Replacing
them with more efficient (but ugly) loops provides a global gain of
about 2%, which is not bad at all !
The filters are now iterated for FE, FI, BE.
Some grey areas remain :
- uri_auth has been propagated to the backend, but in fact it
should be checked at every level (fe, fi, be), depending
where it is declared, and before the filters.
- the HTTP method and URI should be stored and propagated everywhere
they are used. For this, we would need to first apply filters to
be aware of filter changes which affect them.
- there seems to be no need anymore for hdr_idx[0] being empty.
It may contain the start line, which will slightly improve
performance and make the code easier to read.
The req_cap, hdr_state, hdr_idx, auth_hdr and req_line have been moved
to a dedicated hreq structure in the session. It makes is easier to
add HTTP-specific fields such as SOR (start of request) and EOF (end
of headers).
It also made it possible to fix two bugs introduced by last commit :
- end of headers not correctly detected
- hdr_idx not freed upon one specific error during session creation
When the backend side will be reworked, it should rely on a similar
structure.
The code is working again, but not as clean as it could be.
Many blocks should still move to dedicated functions. req->h
must be removed everywhere and updated everytime needed.
A few functions or macros should take care of the headers
during header insertion/deletion/change.
The new parser uses an FSM to strictly follow RFC2616.
Headers are indexed and parsed only once they're all available.
That way, complex regexes make more sense.
HTTP processing is now performed in several phases by calling
multiple functions, making the code cleaner and easier to read.
Note that req[i]pass does not work anymore because it would
require that we mark a header to be ignored. What is really
needed is to have the ability to add an exception to a matching
(match xx except yy).
Several bugs have been fixed in appsession during the conversion
to the new FSM (method length and recovery on malloc errors).
The code does build and work with the debug examples, but is
not usable yet to connect to anything as it does not forward
the requests yet.
This structure will consume 4 bytes per header to keep track of
headers within a request or a response without having to parse
the whole request for each regex. As it's not possible to allocate
only 4 bytes, we define a max number of HTTP headers. We set it
to (BUFSIZE+79)/80 so that 8kB buffers can contain 100 headers
(like Apache), resulting in 400 bytes dedicated to indexation,
or about 400/(2*8kB) ~= 2.4% of the memory usage.
This patch was added in 1.2.9 but was then incidentely reverted by
manipulation error when merging next patch (enforce max number of
conns). It's now merged again.
The references to the proxy from the session have been turned into
Frontend (fe), Filters (fi) and Backend (be). This should ease the
migration to the L7 switching features. Next step will be to kill
the struct proxy and have 3 independant structs instead, each
referenced from entities called listener, frontend, filters and
backend.
Using the cttproxy kernel patch, it's possible to bind to any source
address. It is highly recommended to use the 03-natdel patch with the
other ones.
A new keyword appears as a complement to the "source" keyword : "usesrc".
The source address is mandatory and must be valid on the interface which
will see the packets. The "usesrc" option supports "client" (for full
client_ip:client_port spoofing), "client_ip" (for client_ip spoofing)
and any 'IP[:port]' combination to pretend to be another machine.
Right now, the source binding is missing from server health-checks if
set to another address. It must be implemented (think restricted firewalls).
The doc is still missing too.
Some of the tv_* functions are called very often. Passing their
arguments as registers is quite faster. This can be disabled
by setting CONFIG_HAP_DISABLE_REGPARM.
As suggested by Markus Elfring, a few "const char *" have replaced
some "char *" declarations where a function is not expected to
modify a value. It does not change the code but it helps detecting
coding errors.
Markus Elfring suggested adding a few checks which were missing
after a bunch of getsockopt() and 2 strdup(). While those are
unlikely to fail where they are used, it makes the code cleaner.
Since the connection queueing was introduced, the "redispatch"
option could not cover the cases where a connection has been
refused by the server after having been marked "in progress".
The fix consists in doing a redispatch in the delayed connection
handling code.
Problem reported by Konrad Rzentarzewski.
It is now possible to tarpit connections based on regex matches.
The tarpit timeout is equal to the contimeout. A 500 server error
response is faked, and the logs show the status flags as "PT" which
indicate the connection has been tarpitted.
The timeouts, expiration timers and results are now stored in the buffers.
The timers will have to change a bit to become more flexible, and when the
I/O completion functions will be written, the connect_complete() will have
to be extracted from the write() function.
This makes it possible to relay SSL connections in pure TCP instances while
ensuring the remote end really receives our data eventhough intermediate
agents (firewalls, proxies, ...) might acknowledge the connection.
Too many problem reports were caused by missing timeouts. While
there has never been any default value since version 1.0, having
no timeout is abnormal in networked environments, and will lead
to various problems such as CLOSE_WAIT sockets accumulating and
nasty things like this. For this reason, it's better to annoy
the users until they fix their configs than letting them run
buggy configurations.
The files are now stored under :
- include/haproxy for the generic includes
- include/types.h for the structures needed within prototypes
- include/proto.h for function prototypes and inline functions
- src/*.c for the C files
Most include files are now covered by LGPL. A last move still needs
to be done to put inline functions under GPL and not LGPL.
Version has been set to 1.3.0 in the code but some control still
needs to be done before releasing.
It has been rewritten and now supports an initialization state. It now also
prevents from dumping stopped(disabled) listeners and it is possible to
specify a scope with a list of proxies that are allowed to be dumped from
the one being configured ('.' meaning "this one"). The 'stats' entry can
be configured from the 'defaults' instance and it is correctly flushed
from proxies which redefine it.
Right now it only validates the user/passwd according to a specified list,
and lets the user pass through the proxy if the authentication is OK, and
it refuses any invalid access with a 401 Unauthorized response.
* merged Alexander Lazic's and Klaus Wagner's work on application
cookie-based persistence. Since this is the first merge, this version is
not intended for general use and reports are more than welcome. Some
documentation is really needed though.
