Fix a bug introduced with r182851 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
MFC after:	2 months (along with r182851)

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index 51848ee..02d654b 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1562,7 +1562,7 @@ 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);