Module Name: src
Committed By: tls
Date: Thu Apr 1 00:24:41 UTC 2010
Modified Files:
src/sys/netinet: ip_flow.c tcp_input.c
Log Message:
After discussion with ad@: it appears that KERNEL_LOCK also protects
the driver output path (that is, ifp->if_output()). In the case of
entry through the socket code, we are fine, because pru_usrreq takes
KERNEL_LOCK. However, there are a few other ways to cause output
which require protection:
1) direct calls to tcp_output() in tcp_input()
2) fast-forwarding code (ip_flow) -- protected elsewise
against itself by the softnet lock.
3) *Possibly* the ARP code. I have currently persuaded
myself that it is safe because of how it's called.
4) Possibly the ICMP code.
This change addresses #1 and #2.
To generate a diff of this commit:
cvs rdiff -u -r1.58 -r1.59 src/sys/netinet/ip_flow.c
cvs rdiff -u -r1.300 -r1.301 src/sys/netinet/tcp_input.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/netinet/ip_flow.c
diff -u src/sys/netinet/ip_flow.c:1.58 src/sys/netinet/ip_flow.c:1.59
--- src/sys/netinet/ip_flow.c:1.58 Sun Mar 15 22:16:09 2009
+++ src/sys/netinet/ip_flow.c Thu Apr 1 00:24:41 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: ip_flow.c,v 1.58 2009/03/15 22:16:09 cegger Exp $ */
+/* $NetBSD: ip_flow.c,v 1.59 2010/04/01 00:24:41 tls Exp $ */
/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip_flow.c,v 1.58 2009/03/15 22:16:09 cegger Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_flow.c,v 1.59 2010/04/01 00:24:41 tls Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -301,12 +301,14 @@
else
dst = rtcache_getdst(&ipf->ipf_ro);
+ KERNEL_LOCK(1, NULL);
if ((error = (*rt->rt_ifp->if_output)(rt->rt_ifp, m, dst, rt)) != 0) {
if (error == ENOBUFS)
ipf->ipf_dropped++;
else
ipf->ipf_errors++;
}
+ KERNEL_UNLOCK_ONE(NULL);
return 1;
}
Index: src/sys/netinet/tcp_input.c
diff -u src/sys/netinet/tcp_input.c:1.300 src/sys/netinet/tcp_input.c:1.301
--- src/sys/netinet/tcp_input.c:1.300 Tue Jan 26 18:09:07 2010
+++ src/sys/netinet/tcp_input.c Thu Apr 1 00:24:41 2010
@@ -1,4 +1,4 @@
-/* $NetBSD: tcp_input.c,v 1.300 2010/01/26 18:09:07 pooka Exp $ */
+/* $NetBSD: tcp_input.c,v 1.301 2010/04/01 00:24:41 tls Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -145,7 +145,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.300 2010/01/26 18:09:07 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tcp_input.c,v 1.301 2010/04/01 00:24:41 tls Exp $");
#include "opt_inet.h"
#include "opt_ipsec.h"
@@ -1787,7 +1787,9 @@
sowwakeup(so);
if (so->so_snd.sb_cc)
+ KERNEL_LOCK(1, NULL);
(void) tcp_output(tp);
+ KERNEL_UNLOCK_ONE(NULL);
if (tcp_saveti)
m_freem(tcp_saveti);
return;
@@ -1883,7 +1885,9 @@
sorwakeup(so);
tcp_setup_ack(tp, th);
if (tp->t_flags & TF_ACKNOW)
+ KERNEL_LOCK(1, NULL);
(void) tcp_output(tp);
+ KERNEL_UNLOCK_ONE(NULL);
if (tcp_saveti)
m_freem(tcp_saveti);
return;
@@ -2369,7 +2373,9 @@
goto drop;
} else if (tp->t_dupacks > tcprexmtthresh) {
tp->snd_cwnd += tp->t_segsz;
+ KERNEL_LOCK(1, NULL);
(void) tcp_output(tp);
+ KERNEL_UNLOCK_ONE(NULL);
goto drop;
}
} else {
@@ -2730,7 +2736,9 @@
* Return any desired output.
*/
if (needoutput || (tp->t_flags & TF_ACKNOW)) {
+ KERNEL_LOCK(1, NULL);
(void) tcp_output(tp);
+ KERNEL_UNLOCK_ONE(NULL);
}
if (tcp_saveti)
m_freem(tcp_saveti);
@@ -2767,7 +2775,9 @@
dropafterack2:
m_freem(m);
tp->t_flags |= TF_ACKNOW;
+ KERNEL_LOCK(1, NULL);
(void) tcp_output(tp);
+ KERNEL_UNLOCK_ONE(NULL);
if (tcp_saveti)
m_freem(tcp_saveti);
return;
