diff options
Diffstat (limited to 'sys/netinet/tcp_subr.c')
| -rw-r--r-- | sys/netinet/tcp_subr.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c index 02e753a..474aa52 100644 --- a/sys/netinet/tcp_subr.c +++ b/sys/netinet/tcp_subr.c @@ -76,6 +76,7 @@ #include <netinet6/ip6_var.h> #include <netinet6/nd6.h> #endif +#include <netinet/ip_icmp.h> #include <netinet/tcp.h> #include <netinet/tcp_fsm.h> #include <netinet/tcp_seq.h> @@ -1110,8 +1111,10 @@ tcp_ctlinput(cmd, sa, vip) struct inpcb *inp; struct tcpcb *tp; struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; - tcp_seq icmp_seq; - int s; + struct icmp *icp; + struct in_conninfo inc; + tcp_seq icmp_tcp_seq; + int mtu, s; faddr = ((struct sockaddr_in *)sa)->sin_addr; if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) @@ -1143,6 +1146,8 @@ tcp_ctlinput(cmd, sa, vip) return; if (ip != NULL) { s = splnet(); + icp = (struct icmp *)((caddr_t)ip + - offsetof(struct icmp, icmp_ip)); th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); INP_INFO_WLOCK(&tcbinfo); @@ -1151,17 +1156,41 @@ tcp_ctlinput(cmd, sa, vip) if (inp != NULL) { INP_LOCK(inp); if (inp->inp_socket != NULL) { - icmp_seq = htonl(th->th_seq); + icmp_tcp_seq = htonl(th->th_seq); tp = intotcpcb(inp); - if (SEQ_GEQ(icmp_seq, tp->snd_una) && - SEQ_LT(icmp_seq, tp->snd_max)) + if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && + SEQ_LT(icmp_tcp_seq, tp->snd_max)) { + if (cmd == PRC_MSGSIZE) { + /* + * MTU discovery: + * If we got a needfrag set the MTU + * in the route to the suggested new + * value (if given) and then notify. + * If no new MTU was suggested, then + * we guess a new one less than the + * current value. + * If the new MTU is unreasonably + * small (defined by sysctl tcp_minmss), + * then we up the MTU value to minimum. + */ + bzero(&inc, sizeof(inc)); + inc.inc_flags = 0; /* IPv4 */ + inc.inc_faddr = faddr; + + mtu = ntohs(icp->icmp_nextmtu); + if (!mtu) + mtu = ip_next_mtu(mtu, 1); + if (mtu >= max(296, (tcp_minmss + + sizeof(struct tcpiphdr)))) + tcp_hc_updatemtu(&inc, mtu); + } + inp = (*notify)(inp, inetctlerrmap[cmd]); + } } if (inp != NULL) INP_UNLOCK(inp); } else { - struct in_conninfo inc; - inc.inc_fport = th->th_dport; inc.inc_lport = th->th_sport; inc.inc_faddr = faddr; |
