haproxy/include/proto/proto_tcp.h
Willy Tarreau b686644ad8 [MAJOR] implement tcp request content inspection
Some people need to inspect contents of TCP requests before
deciding to forward a connection or not. A future extension
of this demand might consist in selecting a server farm
depending on the protocol detected in the request.

For this reason, a new state CL_STINSPECT has been added on
the client side. It is immediately entered upon accept() if
the statement "tcp-request inspect-delay <xxx>" is found in
the frontend configuration. Haproxy will then wait up to
this amount of time trying to find a matching ACL, and will
either accept or reject the connection depending on the
"tcp-request content <action> {if|unless}" rules, where
<action> is either "accept" or "reject".

Note that it only waits that long if no definitive verdict
can be found earlier. That generally implies calling a fetch()
function which does not have enough information to decode
some contents, or a match() function which only finds the
beginning of what it's looking for.

It is only at the ACL level that partial data may be processed
as such, because we need to distinguish between MISS and FAIL
*before* applying the term negation.

Thus it is enough to add "| ACL_PARTIAL" to the last argument
when calling acl_exec_cond() to indicate that we expect
ACL_PAT_MISS to be returned if some data is missing (for
fetch() or match()). This is the only case we may return
this value. For this reason, the ACL check in process_cli()
has become a lot simpler.

A new ACL "req_len" of type "int" has been added. Right now
it is already possible to drop requests which talk too early
(eg: for SMTP) or which don't talk at all (eg: HTTP/SSL).

Also, the acl fetch() functions have been extended in order
to permit reporting of missing data in case of fetch failure,
using the ACL_TEST_F_MAY_CHANGE flag.

The default behaviour is unchanged, and if no rule matches,
the request is accepted.

As a side effect, all layer 7 fetching functions have been
cleaned up so that they now check for the validity of the
layer 7 pointer before dereferencing it.
2008-07-16 10:29:07 +02:00

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1.4 KiB
C

/*
include/proto/proto_tcp.h
This file contains TCP socket protocol definitions.
Copyright (C) 2000-2008 Willy Tarreau - w@1wt.eu
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation, version 2.1
exclusively.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _PROTO_PROTO_TCP_H
#define _PROTO_PROTO_TCP_H
#include <common/config.h>
#include <types/proto_tcp.h>
#include <types/session.h>
#include <types/task.h>
int tcp_event_accept(int fd);
int tcpv4_bind_socket(int fd, int flags, struct sockaddr_in *local, struct sockaddr_in *remote);
void tcpv4_add_listener(struct listener *listener);
void tcpv6_add_listener(struct listener *listener);
int tcp_bind_listener(struct listener *listener, char *errmsg, int errlen);
#endif /* _PROTO_PROTO_TCP_H */
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/