Date: Sun, 14 Jul 2002 16:47:18 -0700 (PDT) From: Luigi Rizzo <luigi@FreeBSD.org> To: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/netinet ip_fw.h ip_fw2.c Message-ID: <200207142347.g6ENlIES037731@freefall.freebsd.org>
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luigi 2002/07/14 16:47:18 PDT
Modified files:
sys/netinet ip_fw.h ip_fw2.c
Log:
Implement keepalives for dynamic rules, so they will not expire
just because you leave your session idle.
Also, put in a fix for 64-bit architectures (to be revised).
In detail:
ip_fw.h
* Reorder fields in struct ip_fw to avoid alignment problems on
64-bit machines. This only masks the problem, I am still not
sure whether I am doing something wrong in the code or there
is a problem elsewhere (e.g. different aligmnent of structures
between userland and kernel because of pragmas etc.)
* added fields in dyn_rule to store ack numbers, so we can
generate keepalives when the dynamic rule is about to expire
ip_fw2.c
* use a local function, send_pkt(), to generate TCP RST for Reset rules;
* save about 250 bytes by cleaning up the various snprintf()
in ipfw_log() ...
* ... and use twice as many bytes to implement keepalives
(this seems to be working, but i have not tested it extensively).
Keepalives are generated once every 5 seconds for the last 20 seconds
of the lifetime of a dynamic rule for an established TCP flow. The
packets are sent to both sides, so if at least one of the endpoints
is responding, the timeout is refreshed and the rule will not expire.
You can disable this feature with
sysctl net.inet.ip.fw.dyn_keepalive=0
(the default is 1, to have them enabled).
MFC after: 1 day
(just kidding... I will supply an updated version of ipfw2 for
RELENG_4 tomorrow).
Revision Changes Path
1.72 +5 -3 src/sys/netinet/ip_fw.h
1.5 +145 -104 src/sys/netinet/ip_fw2.c
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