diff options
Diffstat (limited to 'sys/netinet/tcp_timer.c')
| -rw-r--r-- | sys/netinet/tcp_timer.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/sys/netinet/tcp_timer.c b/sys/netinet/tcp_timer.c index 785f68be5621..ae6b97c09cdf 100644 --- a/sys/netinet/tcp_timer.c +++ b/sys/netinet/tcp_timer.c @@ -756,6 +756,16 @@ tcp_timer_rexmt(struct tcpcb *tp) tp->t_flags2 |= TF2_PLPMTU_PMTUD; tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE; tp->t_maxseg = tp->t_pmtud_saved_maxseg; + if (tp->t_maxseg < V_tcp_mssdflt) { + /* + * The MSS is so small we should not + * process incoming SACK's since we are + * subject to attack in such a case. + */ + tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT; + } else { + tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT; + } TCPSTAT_INC(tcps_pmtud_blackhole_failed); /* * Reset the slow-start flight size as it |