svn commit: r201655 - stable/7/sys/netinet
Bjoern A. Zeeb
bz at FreeBSD.org
Wed Jan 6 16:51:58 UTC 2010
Author: bz
Date: Wed Jan 6 16:51:57 2010
New Revision: 201655
URL: http://svn.freebsd.org/changeset/base/201655
Log:
MFC r184722:
Fix a bug introduced with r182851 (r201653 in stable/7) splitting
tcp_mss() into tcp_mss() and tcp_mss_update() so that tcp_mtudisc()
could re-use the same code.
Move the TSO logic back to tcp_mss() and out of tcp_mss_update().
We tried to avoid that initially but if were are called from
tcp_output() with EMSGSIZE, we cleared the TSO flag on the tcpcb
there, called into tcp_mtudisc() and tcp_mss_update() which
then would reenable TSO on the tcpcb based on TSO capabilities
of the interface as learnt in tcp_maxmtu/6().
So if TSO was enabled on the (possibly new) outgoing interface
it was turned back on, which lead to an endless loop between
tcp_output() and tcp_mtudisc() until we overflew the stack.
Reported by: kmacy
Modified:
stable/7/sys/netinet/tcp_input.c
stable/7/sys/netinet/tcp_subr.c
stable/7/sys/netinet/tcp_var.h
Directory Properties:
stable/7/sys/ (props changed)
stable/7/sys/cddl/contrib/opensolaris/ (props changed)
stable/7/sys/contrib/dev/acpica/ (props changed)
stable/7/sys/contrib/pf/ (props changed)
Modified: stable/7/sys/netinet/tcp_input.c
==============================================================================
--- stable/7/sys/netinet/tcp_input.c Wed Jan 6 16:48:59 2010 (r201654)
+++ stable/7/sys/netinet/tcp_input.c Wed Jan 6 16:51:57 2010 (r201655)
@@ -2727,14 +2727,14 @@ tcp_xmit_timer(struct tcpcb *tp, int rtt
* segment. Outgoing SYN/ACK MSS settings are handled in tcp_mssopt().
*/
void
-tcp_mss_update(struct tcpcb *tp, int offer, struct hc_metrics_lite *metricptr)
+tcp_mss_update(struct tcpcb *tp, int offer,
+ struct hc_metrics_lite *metricptr, int *mtuflags)
{
int mss;
u_long maxmtu;
struct inpcb *inp = tp->t_inpcb;
struct hc_metrics_lite metrics;
int origoffer = offer;
- int mtuflags = 0;
#ifdef INET6
int isipv6 = ((inp->inp_vflag & INP_IPV6) != 0) ? 1 : 0;
size_t min_protoh = isipv6 ?
@@ -2749,12 +2749,12 @@ tcp_mss_update(struct tcpcb *tp, int off
/* Initialize. */
#ifdef INET6
if (isipv6) {
- maxmtu = tcp_maxmtu6(&inp->inp_inc, &mtuflags);
+ maxmtu = tcp_maxmtu6(&inp->inp_inc, mtuflags);
tp->t_maxopd = tp->t_maxseg = tcp_v6mssdflt;
} else
#endif
{
- maxmtu = tcp_maxmtu(&inp->inp_inc, &mtuflags);
+ maxmtu = tcp_maxmtu(&inp->inp_inc, mtuflags);
tp->t_maxopd = tp->t_maxseg = tcp_mssdflt;
}
@@ -2772,10 +2772,6 @@ tcp_mss_update(struct tcpcb *tp, int off
return;
}
- /* Check the interface for TSO capabilities. */
- if (mtuflags & CSUM_TSO)
- tp->t_flags |= TF_TSO;
-
/* What have we got? */
switch (offer) {
case 0:
@@ -2894,12 +2890,13 @@ tcp_mss(struct tcpcb *tp, int offer)
struct inpcb *inp;
struct socket *so;
struct hc_metrics_lite metrics;
+ int mtuflags = 0;
#ifdef INET6
int isipv6;
#endif
KASSERT(tp != NULL, ("%s: tp == NULL", __func__));
- tcp_mss_update(tp, offer, &metrics);
+ tcp_mss_update(tp, offer, &metrics, &mtuflags);
mss = tp->t_maxseg;
inp = tp->t_inpcb;
@@ -3012,6 +3009,10 @@ tcp_mss(struct tcpcb *tp, int offer)
tp->snd_cwnd = mss * ss_fltsz_local;
else
tp->snd_cwnd = mss * ss_fltsz;
+
+ /* Check the interface for TSO capabilities. */
+ if (mtuflags & CSUM_TSO)
+ tp->t_flags |= TF_TSO;
}
/*
Modified: stable/7/sys/netinet/tcp_subr.c
==============================================================================
--- stable/7/sys/netinet/tcp_subr.c Wed Jan 6 16:48:59 2010 (r201654)
+++ stable/7/sys/netinet/tcp_subr.c Wed Jan 6 16:51:57 2010 (r201655)
@@ -1519,7 +1519,7 @@ tcp_mtudisc(struct inpcb *inp, int errno
tp = intotcpcb(inp);
KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
- tcp_mss_update(tp, -1, NULL);
+ tcp_mss_update(tp, -1, NULL, NULL);
so = inp->inp_socket;
SOCKBUF_LOCK(&so->so_snd);
Modified: stable/7/sys/netinet/tcp_var.h
==============================================================================
--- stable/7/sys/netinet/tcp_var.h Wed Jan 6 16:48:59 2010 (r201654)
+++ stable/7/sys/netinet/tcp_var.h Wed Jan 6 16:51:57 2010 (r201655)
@@ -544,7 +544,7 @@ void tcp_reass_init(void);
void tcp_input(struct mbuf *, int);
u_long tcp_maxmtu(struct in_conninfo *, int *);
u_long tcp_maxmtu6(struct in_conninfo *, int *);
-void tcp_mss_update(struct tcpcb *, int, struct hc_metrics_lite *);
+void tcp_mss_update(struct tcpcb *, int, struct hc_metrics_lite *, int *);
void tcp_mss(struct tcpcb *, int);
int tcp_mssopt(struct in_conninfo *);
struct inpcb *
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