diff options
Diffstat (limited to 'sys/netinet/tcp_output.c')
| -rw-r--r-- | sys/netinet/tcp_output.c | 63 |
1 files changed, 62 insertions, 1 deletions
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c index 625bca510c8..2453d4c132c 100644 --- a/sys/netinet/tcp_output.c +++ b/sys/netinet/tcp_output.c @@ -1,4 +1,4 @@ -/* $OpenBSD: tcp_output.c,v 1.49 2002/03/08 03:49:58 provos Exp $ */ +/* $OpenBSD: tcp_output.c,v 1.50 2002/05/16 14:10:51 kjc Exp $ */ /* $NetBSD: tcp_output.c,v 1.16 1997/06/03 16:17:09 kml Exp $ */ /* @@ -237,6 +237,9 @@ tcp_output(tp) #ifdef TCP_SIGNATURE unsigned int sigoff; #endif /* TCP_SIGNATURE */ +#ifdef TCP_ECN + int needect; +#endif #if defined(TCP_SACK) && defined(TCP_SIGNATURE) && defined(DIAGNOSTIC) if (!tp->sack_disable && (tp->t_flags & TF_SIGNATURE)) @@ -815,6 +818,39 @@ send: bcopy((caddr_t)opt, (caddr_t)(th + 1), optlen); th->th_off = (sizeof (struct tcphdr) + optlen) >> 2; } +#ifdef TCP_ECN + if (tcp_do_ecn) { + /* + * if we have received congestion experienced segs, + * set ECE bit. + */ + if (tp->t_flags & TF_RCVD_CE) { + flags |= TH_ECE; + tcpstat.tcps_ecn_sndece++; + } + if (!(tp->t_flags & TF_DISABLE_ECN)) { + /* + * if this is a SYN seg, set ECE and CWR. + * set only ECE for SYN-ACK if peer supports ECN. + */ + if ((flags & (TH_SYN|TH_ACK)) == TH_SYN) + flags |= (TH_ECE|TH_CWR); + else if ((tp->t_flags & TF_ECN_PERMIT) && + (flags & (TH_SYN|TH_ACK)) == (TH_SYN|TH_ACK)) + flags |= TH_ECE; + } + /* + * if we have reduced the congestion window, notify + * the peer by setting CWR bit. + */ + if ((tp->t_flags & TF_ECN_PERMIT) && + (tp->t_flags & TF_SEND_CWR)) { + flags |= TH_CWR; + tp->t_flags &= ~TF_SEND_CWR; + tcpstat.tcps_ecn_sndcwr++; + } + } +#endif th->th_flags = flags; /* @@ -1038,6 +1074,23 @@ send: */ m->m_pkthdr.len = hdrlen + len; +#ifdef TCP_ECN + /* + * if peer is ECN capable, set the ECT bit in the IP header. + * but don't set ECT for a pure ack, a retransmit or a window probe. + */ + needect = 0; + if (tcp_do_ecn && (tp->t_flags & TF_ECN_PERMIT)) { + if (len == 0 || SEQ_LT(tp->snd_nxt, tp->snd_max) || + (tp->t_force && len == 1)) { + /* don't set ECT */ + } else { + needect = 1; + tcpstat.tcps_ecn_sndect++; + } + } +#endif + switch (tp->pf) { case 0: /*default to PF_INET*/ #ifdef INET @@ -1049,6 +1102,10 @@ send: ip->ip_len = m->m_pkthdr.len; ip->ip_ttl = tp->t_inpcb->inp_ip.ip_ttl; ip->ip_tos = tp->t_inpcb->inp_ip.ip_tos; +#ifdef TCP_ECN + if (needect) + ip->ip_tos |= IPTOS_ECN_ECT0; +#endif } error = ip_output(m, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route, @@ -1067,6 +1124,10 @@ send: sizeof(struct ip6_hdr); ipv6->ip6_nxt = IPPROTO_TCP; ipv6->ip6_hlim = in6_selecthlim(tp->t_inpcb, NULL); +#ifdef TCP_ECN + if (needect) + ipv6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20); +#endif } error = ip6_output(m, tp->t_inpcb->inp_outputopts6, &tp->t_inpcb->inp_route6, |