diff options
| author | Markus Friedl <markus@cvs.openbsd.org> | 2005-08-11 11:39:37 +0000 |
|---|---|---|
| committer | Markus Friedl <markus@cvs.openbsd.org> | 2005-08-11 11:39:37 +0000 |
| commit | 2e4382bf57c8db77699440b5fbea9447891f2d34 (patch) | |
| tree | cb986dd7ba6227423b737a8114c447690c522b40 /sys/netinet | |
| parent | 0300260e07ec721ec54647e3542045abfeca08c8 (diff) | |
don't accept SYN-only TCP options for established connections;
cf FreeBSD-SA-05:15.tcp; ok claudio, mcbride
Diffstat (limited to 'sys/netinet')
| -rw-r--r-- | sys/netinet/tcp_input.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index 1e011cfd75a..71ff36cf3df 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tcp_input.c,v 1.189 2005/08/02 11:05:44 markus Exp $ */ +/* $OpenBSD: tcp_input.c,v 1.190 2005/08/11 11:39:36 markus Exp $ */ /* $NetBSD: tcp_input.c,v 1.23 1996/02/13 23:43:44 christos Exp $ */ /* @@ -2257,6 +2257,8 @@ tcp_dooptions(tp, cp, cnt, th, m, iphlen, oi) continue; if (!(th->th_flags & TH_SYN)) continue; + if (TCPS_HAVERCVDSYN(tp->t_state)) + continue; bcopy((char *) cp + 2, (char *) &mss, sizeof(mss)); NTOHS(mss); oi->maxseg = mss; @@ -2267,6 +2269,8 @@ tcp_dooptions(tp, cp, cnt, th, m, iphlen, oi) continue; if (!(th->th_flags & TH_SYN)) continue; + if (TCPS_HAVERCVDSYN(tp->t_state)) + continue; tp->t_flags |= TF_RCVD_SCALE; tp->requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT); break; @@ -2280,24 +2284,29 @@ tcp_dooptions(tp, cp, cnt, th, m, iphlen, oi) bcopy(cp + 6, &oi->ts_ecr, sizeof(oi->ts_ecr)); NTOHL(oi->ts_ecr); + if (!(th->th_flags & TH_SYN)) + continue; + if (TCPS_HAVERCVDSYN(tp->t_state)) + continue; /* * A timestamp received in a SYN makes * it ok to send timestamp requests and replies. */ - if (th->th_flags & TH_SYN) { - tp->t_flags |= TF_RCVD_TSTMP; - tp->ts_recent = oi->ts_val; - tp->ts_recent_age = tcp_now; - } + tp->t_flags |= TF_RCVD_TSTMP; + tp->ts_recent = oi->ts_val; + tp->ts_recent_age = tcp_now; break; #ifdef TCP_SACK case TCPOPT_SACK_PERMITTED: if (!tp->sack_enable || optlen!=TCPOLEN_SACK_PERMITTED) continue; - if (th->th_flags & TH_SYN) - /* MUST only be set on SYN */ - tp->t_flags |= TF_SACK_PERMIT; + if (!(th->th_flags & TH_SYN)) + continue; + if (TCPS_HAVERCVDSYN(tp->t_state)) + continue; + /* MUST only be set on SYN */ + tp->t_flags |= TF_SACK_PERMIT; break; case TCPOPT_SACK: tcp_sack_option(tp, th, cp, optlen); @@ -3965,10 +3974,10 @@ syn_cache_add(src, dst, th, iphlen, so, m, optp, optlen, oi) #endif tb.t_flags = tcp_do_rfc1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0; #ifdef TCP_SIGNATURE - tb.t_state = TCPS_LISTEN; if (tp->t_flags & TF_SIGNATURE) tb.t_flags |= TF_SIGNATURE; #endif + tb.t_state = TCPS_LISTEN; if (tcp_dooptions(&tb, optp, optlen, th, m, iphlen, oi)) return (0); } else |