diff options
Diffstat (limited to 'sys/netinet/tcp_subr.c')
| -rw-r--r-- | sys/netinet/tcp_subr.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c index 312740ccf599..306053ae8289 100644 --- a/sys/netinet/tcp_subr.c +++ b/sys/netinet/tcp_subr.c @@ -1793,6 +1793,7 @@ tcpip_maketemplate(struct inpcb *inp) * * NOTE: If m != NULL, then th must point to *inside* the mbuf. */ + void tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, tcp_seq ack, tcp_seq seq, uint16_t flags) @@ -3320,8 +3321,19 @@ tcp_mtudisc(struct inpcb *inp, int mtuoffer) so = inp->inp_socket; SOCKBUF_LOCK(&so->so_snd); /* If the mss is larger than the socket buffer, decrease the mss. */ - if (so->so_snd.sb_hiwat < tp->t_maxseg) + if (so->so_snd.sb_hiwat < tp->t_maxseg) { tp->t_maxseg = so->so_snd.sb_hiwat; + 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; + } + } SOCKBUF_UNLOCK(&so->so_snd); TCPSTAT_INC(tcps_mturesent); @@ -3454,8 +3466,19 @@ tcp6_use_min_mtu(struct tcpcb *tp) opt = inp->in6p_outputopts; if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL && - tp->t_maxseg > TCP6_MSS) + tp->t_maxseg > TCP6_MSS) { tp->t_maxseg = TCP6_MSS; + 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; + } + } } } #endif /* INET6 */ |