diff options
| -rw-r--r-- | sys/netinet/tcp_subr.c | 19 | ||||
| -rw-r--r-- | sys/netinet/tcp_timewait.c | 19 | ||||
| -rw-r--r-- | sys/netinet/tcp_var.h | 5 |
3 files changed, 22 insertions, 21 deletions
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c index d166bba..0fe5d0f 100644 --- a/sys/netinet/tcp_subr.c +++ b/sys/netinet/tcp_subr.c @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 - * $Id: tcp_subr.c,v 1.16 1995/09/22 17:43:37 wollman Exp $ + * $Id: tcp_subr.c,v 1.17 1995/10/03 16:54:15 wollman Exp $ */ #include <sys/param.h> @@ -503,6 +503,8 @@ tcp_mtudisc(inp, errno) offered = taop->tao_mssopt; mss = rt->rt_rmx.rmx_mtu - sizeof(struct tcpiphdr); mss = min(mss, offered); + if (tp->t_maxopd <= mss) + return; tp->t_maxopd = mss; if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && @@ -523,15 +525,12 @@ tcp_mtudisc(inp, errno) tp->t_maxseg = mss; - /* - * Nudge TCP output. Unfortunately, we have no way to know - * which packet that we sent is the failing one, but in the - * vast majority of cases we expect that it will be at the - * beginning of the window, so this should do the right - * thing (I hope). - */ - tp->snd_nxt = tp->snd_una; - tcp_output(tp); + if (SEQ_GT(tp->snd_una, tp->t_lastmturesend)) { + tcpstat.tcps_mturesent++; + tp->t_rtt = 0; + tp->snd_nxt = tp->t_lastmturesend = tp->snd_una; + tcp_output(tp); + } } } #endif /* MTUDISC */ diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c index d166bba..0fe5d0f 100644 --- a/sys/netinet/tcp_timewait.c +++ b/sys/netinet/tcp_timewait.c @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 - * $Id: tcp_subr.c,v 1.16 1995/09/22 17:43:37 wollman Exp $ + * $Id: tcp_subr.c,v 1.17 1995/10/03 16:54:15 wollman Exp $ */ #include <sys/param.h> @@ -503,6 +503,8 @@ tcp_mtudisc(inp, errno) offered = taop->tao_mssopt; mss = rt->rt_rmx.rmx_mtu - sizeof(struct tcpiphdr); mss = min(mss, offered); + if (tp->t_maxopd <= mss) + return; tp->t_maxopd = mss; if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && @@ -523,15 +525,12 @@ tcp_mtudisc(inp, errno) tp->t_maxseg = mss; - /* - * Nudge TCP output. Unfortunately, we have no way to know - * which packet that we sent is the failing one, but in the - * vast majority of cases we expect that it will be at the - * beginning of the window, so this should do the right - * thing (I hope). - */ - tp->snd_nxt = tp->snd_una; - tcp_output(tp); + if (SEQ_GT(tp->snd_una, tp->t_lastmturesend)) { + tcpstat.tcps_mturesent++; + tp->t_rtt = 0; + tp->snd_nxt = tp->t_lastmturesend = tp->snd_una; + tcp_output(tp); + } } } #endif /* MTUDISC */ diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h index bfdb425..759b793 100644 --- a/sys/netinet/tcp_var.h +++ b/sys/netinet/tcp_var.h @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * @(#)tcp_var.h 8.4 (Berkeley) 5/24/95 - * $Id: tcp_var.h,v 1.17 1995/09/22 07:40:18 peter Exp $ + * $Id: tcp_var.h,v 1.18 1995/10/04 20:49:03 wollman Exp $ */ #ifndef _NETINET_TCP_VAR_H_ @@ -141,6 +141,8 @@ struct tcpcb { caddr_t t_tuba_pcb; /* next level down pcb for TCP over z */ /* More RTT stuff */ u_long t_rttupdated; /* number of times rtt sampled */ +/* For MTU discovery */ + tcp_seq t_lastmturesend; /* seq of resend for mtu discovery */ }; /* @@ -287,6 +289,7 @@ struct tcpstat { u_long tcps_usedssthresh; /* times ssthresh initialized from rt*/ u_long tcps_persistdrop; /* timeout in persist state */ u_long tcps_badsyn; /* bogus SYN, e.g. premature ACK */ + u_long tcps_mturesent; /* resends due to MTU discovery */ }; /* |
