diff options
Diffstat (limited to 'sys/netinet/tcp_subr.c')
| -rw-r--r-- | sys/netinet/tcp_subr.c | 76 |
1 files changed, 64 insertions, 12 deletions
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c index 8558464fb70a..eea64bb08ab1 100644 --- a/sys/netinet/tcp_subr.c +++ b/sys/netinet/tcp_subr.c @@ -31,7 +31,7 @@ * SUCH DAMAGE. * * from: @(#)tcp_subr.c 7.20 (Berkeley) 12/1/90 - * $Id: tcp_subr.c,v 1.2 1993/10/16 18:26:31 rgrimes Exp $ + * $Id: tcp_subr.c,v 1.6 1993/12/19 00:52:50 wollman Exp $ */ #include "param.h" @@ -50,6 +50,7 @@ #include "in_systm.h" #include "ip.h" #include "in_pcb.h" +#include "in_var.h" #include "ip_var.h" #include "ip_icmp.h" #include "tcp.h" @@ -59,16 +60,18 @@ #include "tcp_var.h" #include "tcpip.h" -/* patchable/settable parameters for tcp */ -int tcp_ttl = TCP_TTL; -int tcp_mssdflt = TCP_MSS; -int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; +tcp_seq tcp_iss; +struct inpcb tcb; +struct tcpstat tcpstat; -extern struct inpcb *tcp_last_inpcb; +#ifdef MTUDISC +int tcp_mtuchanged(struct inpcb *, int); +#endif /* * Tcp initialization */ +void tcp_init() { @@ -133,6 +136,7 @@ tcp_template(tp) * In any case the ack and sequence number of the transmitted * segment are as specified by the parameters. */ +void tcp_respond(tp, ti, m, ack, seq, flags) struct tcpcb *tp; register struct tcpiphdr *ti; @@ -227,6 +231,13 @@ tcp_newtcpcb(inp) tp->snd_ssthresh = TCP_MAXWIN; inp->inp_ip.ip_ttl = tcp_ttl; inp->inp_ppcb = (caddr_t)tp; +#ifdef MTUDISC + /* + * Enable Path MTU Discovery on this PCB. + */ + inp->inp_mtunotify = tcp_mtuchanged; + inp->inp_flags |= INP_DISCOVERMTU; +#endif /* MTUDISC */ return (tp); } @@ -286,7 +297,7 @@ tcp_close(tp) if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && (rt = inp->inp_route.ro_rt) && ((struct sockaddr_in *)rt_key(rt))->sin_addr.s_addr != INADDR_ANY) { - register u_long i; + register u_long i = 0; if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { i = tp->t_srtt * @@ -337,7 +348,7 @@ tcp_close(tp) rt->rt_rmx.rmx_ssthresh = i; } } -#endif RTV_RTT +#endif /* RTV_RTT */ /* free the reassembly queue, if any */ t = tp->seg_next; while (t != (struct tcpiphdr *)tp) { @@ -359,6 +370,7 @@ tcp_close(tp) return ((struct tcpcb *)0); } +void tcp_drain() { @@ -369,6 +381,7 @@ tcp_drain() * store error as soft error, but wake up user * (for now, won't do anything until can select for soft error). */ +void tcp_notify(inp, error) register struct inpcb *inp; int error; @@ -380,18 +393,55 @@ tcp_notify(inp, error) sowwakeup(inp->inp_socket); } +/* + * When we get a PRC_MSGSIZE error (generated by the ICMP layer upon + * receipt of an ICMP_UNREACH_NEEDFRAG message), we need to get the + * IP layer to check the cached MTU data that it has in its PCBs. + * If things have changed, this will cause us to receive a + * PRC_MTUCHANGED message for /every/ connection to the same + * destination; that is handled by he tcp_mtuchanged() function, + * below. + * + * In the immortal words of Ken and Dennis, ``You are not expected to + * understand this.'' + */ +void +tcp_checkmtu(struct inpcb *inp, int error) { +#ifdef MTUDISC + /* + * XXX - this should also cause an immediate retransmission and + * slow start, since we know for a fact that the message we just sent + * got dropped on the floor. For now, just do what tcp_quench does. + */ + tcp_quench(inp); + in_pcbmtu(inp); +#endif /* MTUDISC */ +} + +#ifdef MTUDISC +int /* grrr... should be void... */ +tcp_mtuchanged(struct inpcb *inp, int error) { + /* don't do anything just yet... */; +} +#endif /* MTUDISC */ + +void tcp_ctlinput(cmd, sa, ip) int cmd; struct sockaddr *sa; register struct ip *ip; { register struct tcphdr *th; - extern struct in_addr zeroin_addr; - extern u_char inetctlerrmap[]; - int (*notify)() = tcp_notify, tcp_quench(); + void (*notify)(struct inpcb *, int) = tcp_notify; if (cmd == PRC_QUENCH) notify = tcp_quench; +#ifdef MTUDISC + else if (cmd == PRC_MSGSIZE) + notify = tcp_checkmtu; + else if (cmd == PRC_MTUCHANGED) /* just in case */ + notify = tcp_mtuchanged; +#endif /* MTUDISC */ else if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0) return; if (ip) { @@ -406,8 +456,10 @@ tcp_ctlinput(cmd, sa, ip) * When a source quench is received, close congestion window * to one segment. We will gradually open it again as we proceed. */ -tcp_quench(inp) +void +tcp_quench(inp, errno) struct inpcb *inp; + int errno; { struct tcpcb *tp = intotcpcb(inp); |