Date: Tue, 28 Nov 2006 23:19:18 +0000 (UTC) From: Robert Watson <rwatson@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/netinet ip_output.c ip_var.h tcp_usrreq.c Message-ID: <200611282319.kASNJIji015235@repoman.freebsd.org>
next in thread | raw e-mail | index | archive | help
rwatson 2006-11-28 23:19:18 UTC
FreeBSD src repository
Modified files: (Branch: RELENG_6_2)
sys/netinet ip_output.c ip_var.h tcp_usrreq.c
Log:
Merge ip_output.c:1.242.2.17, ip_var.h:1.95.2.1, tcp_usrreq.c:1.124.2.4
from RELENG_6 to RELENG_6_2:
Reformulate ip_ctloutput() and tcp_ctloutput() to work around the fact
that so_pcb can be invalidated at any time due to an untimely reset.
Move the body of ip_ctloutput() to ip_ctloutput_pcbinfo(), which
accepts a pcbinfo argument, and wrap it with ip_ctloutput(), which
passes a NULL. Modify tcp_ctloutput() to directly invoke
ip_ctloutput_pcbinfo() and pass tcbinfo. Hold the pcbinfo lock when
dereferencing so_pcb and acquiring the inpcb lock in order to prevent
the inpcb from being freed; the pcbinfo lock is then immediately
dropped. This is required as TCP may free the inppcb and invalidate
so_pcb due to a reset at any time in the RELENG_6 network stack, which
otherwise leads to a panic.
This panic might be frequently seen on highly loaded IRC and Samba
servers, which have long-lasting TCP connections, query socket options
frequently, and see a significant number of reset connections.
This change has been merged directly to RELENG_6 as the problem does
not exist in HEAD, where the invariants for so_pcb are much stronger;
the architectural changes in HEAD avoid the need to acquire a global
lock in the socket option path. This change will be merged to
RELENG_6_2.
PR: 102412, 104765
Reviewed by: Diane Bruce <db at db.net>
Tested by: Daniel Austin <daniel at kewlio dot net>,
Kai Gallasch <gallasch at free dot de>
Approved by: re (kensmith)
Revision Changes Path
1.242.2.16.2.1 +34 -1 src/sys/netinet/ip_output.c
1.95.8.1 +3 -0 src/sys/netinet/ip_var.h
1.124.2.3.2.1 +1 -1 src/sys/netinet/tcp_usrreq.c
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200611282319.kASNJIji015235>