tcp_timewait.c revision 6475
1139804Simp/* 21541Srgrimes * Copyright (c) 1982, 1986, 1988, 1990, 1993 31541Srgrimes * The Regents of the University of California. All rights reserved. 41541Srgrimes * 51541Srgrimes * Redistribution and use in source and binary forms, with or without 61541Srgrimes * modification, are permitted provided that the following conditions 71541Srgrimes * are met: 81541Srgrimes * 1. Redistributions of source code must retain the above copyright 987218Srwatson * notice, this list of conditions and the following disclaimer. 101541Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111541Srgrimes * notice, this list of conditions and the following disclaimer in the 121541Srgrimes * documentation and/or other materials provided with the distribution. 131541Srgrimes * 3. All advertising materials mentioning features or use of this software 141541Srgrimes * must display the following acknowledgement: 151541Srgrimes * This product includes software developed by the University of 161541Srgrimes * California, Berkeley and its contributors. 171541Srgrimes * 4. Neither the name of the University nor the names of its contributors 181541Srgrimes * may be used to endorse or promote products derived from this software 191541Srgrimes * without specific prior written permission. 201541Srgrimes * 211541Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221541Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231541Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241541Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251541Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261541Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271541Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281541Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291541Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301541Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311541Srgrimes * SUCH DAMAGE. 321541Srgrimes * 331541Srgrimes * @(#)tcp_subr.c 8.1 (Berkeley) 6/10/93 341541Srgrimes * $Id: tcp_subr.c,v 1.6 1995/02/09 23:13:25 wollman Exp $ 351541Srgrimes */ 361541Srgrimes 371541Srgrimes#include <sys/param.h> 381541Srgrimes#include <sys/proc.h> 391541Srgrimes#include <sys/systm.h> 401541Srgrimes#include <sys/malloc.h> 411541Srgrimes#include <sys/mbuf.h> 42116182Sobrien#include <sys/socket.h> 43116182Sobrien#include <sys/socketvar.h> 44116182Sobrien#include <sys/protosw.h> 4531778Seivind#include <sys/errno.h> 46101001Srwatson 4731778Seivind#include <net/route.h> 481541Srgrimes#include <net/if.h> 4976166Smarkm 501541Srgrimes#include <netinet/in.h> 51132548Srwatson#include <netinet/in_systm.h> 5241059Speter#include <netinet/ip.h> 5370317Sjake#include <netinet/in_pcb.h> 54101173Srwatson#include <netinet/ip_var.h> 5591140Stanimura#include <netinet/ip_icmp.h> 5676166Smarkm#include <netinet/tcp.h> 5791140Stanimura#define TCPOUTFLAGS 581541Srgrimes#include <netinet/tcp_fsm.h> 5976166Smarkm#include <netinet/tcp_seq.h> 6087218Srwatson#include <netinet/tcp_timer.h> 6131891Ssef#include <netinet/tcp_var.h> 6265495Struckman#include <netinet/tcpip.h> 6392976Srwatson#ifdef TCPDEBUG 6492976Srwatson#include <netinet/tcp_debug.h> 6561287Srwatson#endif 661541Srgrimes 6730354Sphk/* patchable/settable parameters for tcp */ 6830354Sphkint tcp_mssdflt = TCP_MSS; 6989414Sarrint tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; 7089414Sarrint tcp_do_rfc1323 = 1; 7187138Srwatsonint tcp_do_rfc1644 = 1; 7287138Srwatsonstatic void tcp_cleartaocache(void); 7312221Sbde 7411332Sswallaceextern struct inpcb *tcp_last_inpcb; 751541Srgrimes 761541Srgrimes/* 7712221Sbde * Tcp initialization 7858717Sdillon */ 7982749Sdillonvoid 8082749Sdillontcp_init() 811541Srgrimes{ 821549Srgrimes 8393580Sjhb tcp_iss = 1; /* wrong */ 841541Srgrimes tcp_ccgen = 1; 8583366Sjulian tcp_cleartaocache(); 861541Srgrimes tcb.inp_next = tcb.inp_prev = &tcb; 8783366Sjulian if (max_protohdr < sizeof(struct tcpiphdr)) 88130344Sphk max_protohdr = sizeof(struct tcpiphdr); 8974728Sjhb if (max_linkhdr + sizeof(struct tcpiphdr) > MHLEN) 9083366Sjulian panic("tcp_init"); 9174728Sjhb} 921541Srgrimes 931541Srgrimes/* 941541Srgrimes * Create template to be used to send tcp packets on a connection. 951541Srgrimes * Call after host entry created, allocates an mbuf and fills 9612221Sbde * in a skeletal tcp/ip header, minimizing the amount of work 9711332Sswallace * necessary when the connection is used. 9811332Sswallace */ 9911332Sswallacestruct tcpiphdr * 10012221Sbdetcp_template(tp) 10182749Sdillon struct tcpcb *tp; 10282749Sdillon{ 10382749Sdillon register struct inpcb *inp = tp->t_inpcb; 1041541Srgrimes register struct mbuf *m; 1051549Srgrimes register struct tcpiphdr *n; 10693580Sjhb 1071541Srgrimes if ((n = tp->t_template) == 0) { 10883366Sjulian m = m_get(M_DONTWAIT, MT_HEADER); 1091541Srgrimes if (m == NULL) 11074728Sjhb return (0); 11183366Sjulian m->m_len = sizeof (struct tcpiphdr); 11274728Sjhb n = mtod(m, struct tcpiphdr *); 1131541Srgrimes } 1141541Srgrimes n->ti_next = n->ti_prev = 0; 1151541Srgrimes n->ti_x1 = 0; 11687466Srwatson n->ti_pr = IPPROTO_TCP; 11787218Srwatson n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip)); 11858717Sdillon n->ti_src = inp->inp_laddr; 11912221Sbde n->ti_dst = inp->inp_faddr; 12011332Sswallace n->ti_sport = inp->inp_lport; 12111332Sswallace n->ti_dport = inp->inp_fport; 12211332Sswallace n->ti_seq = 0; 12312221Sbde n->ti_ack = 0; 12482749Sdillon n->ti_x2 = 0; 12582749Sdillon n->ti_off = 5; 12682749Sdillon n->ti_flags = 0; 1271549Srgrimes n->ti_win = 0; 12893580Sjhb n->ti_sum = 0; 1291541Srgrimes n->ti_urp = 0; 13083366Sjulian return (n); 1311541Srgrimes} 13291140Stanimura 13383366Sjulian/* 13491140Stanimura * Send a single message to the TCP at address specified by 1351541Srgrimes * the given TCP/IP header. If m == 0, then we make a copy 1361541Srgrimes * of the tcpiphdr at ti and send directly to the addressed host. 1371541Srgrimes * This is used to force keep alive messages out using the TCP 13828401Speter * template for a connection tp->t_template. If flags are given 13912221Sbde * then we send a message back to the TCP which originated the 14028401Speter * segment ti, and discard the mbuf containing it and any other 14128401Speter * attached mbufs. 14228401Speter * 14328401Speter * In any case the ack and sequence number of the transmitted 14482749Sdillon * segment are as specified by the parameters. 14582749Sdillon */ 14682749Sdillonvoid 14728401Spetertcp_respond(tp, ti, m, ack, seq, flags) 14893580Sjhb struct tcpcb *tp; 14928401Speter register struct tcpiphdr *ti; 150114031Sjhb register struct mbuf *m; 15192985Sjhb tcp_seq ack, seq; 15241726Struckman int flags; 15391140Stanimura{ 154114031Sjhb register int tlen; 15591140Stanimura int win = 0; 156114031Sjhb struct route *ro = 0; 157114031Sjhb 158114031Sjhb if (tp) { 159114031Sjhb win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); 160114031Sjhb ro = &tp->t_inpcb->inp_route; 161114031Sjhb } 162114031Sjhb if (m == 0) { 163114031Sjhb m = m_gethdr(M_DONTWAIT, MT_HEADER); 164114031Sjhb if (m == NULL) 16575893Sjhb return; 166114031Sjhb#ifdef TCP_COMPAT_42 167114031Sjhb tlen = 1; 168114031Sjhb#else 16928401Speter tlen = 0; 17028401Speter#endif 17128401Speter m->m_data += max_linkhdr; 17228401Speter *mtod(m, struct tcpiphdr *) = *ti; 17328401Speter ti = mtod(m, struct tcpiphdr *); 17428401Speter flags = TH_ACK; 17528401Speter } else { 17628401Speter m_freem(m->m_next); 17728401Speter m->m_next = 0; 17828401Speter m->m_data = (caddr_t)ti; 17982749Sdillon m->m_len = sizeof (struct tcpiphdr); 18082749Sdillon tlen = 0; 18182749Sdillon#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 18228401Speter xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_long); 18393580Sjhb xchg(ti->ti_dport, ti->ti_sport, u_short); 18428401Speter#undef xchg 185114031Sjhb } 18687218Srwatson ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen)); 18741726Struckman tlen += sizeof (struct tcpiphdr); 18891140Stanimura m->m_len = tlen; 189114031Sjhb m->m_pkthdr.len = tlen; 19091140Stanimura m->m_pkthdr.rcvif = (struct ifnet *) 0; 191114031Sjhb ti->ti_next = ti->ti_prev = 0; 192114031Sjhb ti->ti_x1 = 0; 193114031Sjhb ti->ti_seq = htonl(seq); 194114031Sjhb ti->ti_ack = htonl(ack); 195114031Sjhb ti->ti_x2 = 0; 196114031Sjhb ti->ti_off = sizeof (struct tcphdr) >> 2; 197114031Sjhb ti->ti_flags = flags; 198114031Sjhb if (tp) 199114031Sjhb ti->ti_win = htons((u_short) (win >> tp->rcv_scale)); 20075893Sjhb else 201114031Sjhb ti->ti_win = htons((u_short)win); 202114031Sjhb ti->ti_urp = 0; 203114031Sjhb ti->ti_sum = 0; 20428401Speter ti->ti_sum = in_cksum(m, tlen); 20528401Speter ((struct ip *)ti)->ip_len = tlen; 20628401Speter ((struct ip *)ti)->ip_ttl = ip_defttl; 20711332Sswallace#ifdef TCPDEBUG 20811332Sswallace if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) 20911332Sswallace tcp_trace(TA_OUTPUT, 0, tp, ti, 0); 21012221Sbde#endif 21182749Sdillon (void) ip_output(m, NULL, ro, 0, NULL); 21282749Sdillon} 21382749Sdillon 2141541Srgrimes/* 2151549Srgrimes * Create a new TCP control block, making an 21693580Sjhb * empty reassembly queue and hooking it to the argument 2171541Srgrimes * protocol control block. 2181541Srgrimes */ 21992987Sjhbstruct tcpcb * 220130344Sphktcp_newtcpcb(inp) 22192987Sjhb struct inpcb *inp; 2221541Srgrimes{ 2231541Srgrimes register struct tcpcb *tp; 2241541Srgrimes 2251541Srgrimes tp = malloc(sizeof(*tp), M_PCB, M_NOWAIT); 22612221Sbde if (tp == NULL) 22711332Sswallace return ((struct tcpcb *)0); 22811332Sswallace bzero((char *) tp, sizeof(struct tcpcb)); 22911332Sswallace tp->seg_next = tp->seg_prev = (struct tcpiphdr *)tp; 23012221Sbde tp->t_maxseg = tp->t_maxopd = tcp_mssdflt; 23187218Srwatson 23287218Srwatson if (tcp_do_rfc1323) 23387218Srwatson tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 2341541Srgrimes if (tcp_do_rfc1644) 2351549Srgrimes tp->t_flags |= TF_REQ_CC; 23693580Sjhb tp->t_inpcb = inp; 2371541Srgrimes /* 23892987Sjhb * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 23992987Sjhb * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives 2401541Srgrimes * reasonable initial retransmit time. 2411541Srgrimes */ 2421541Srgrimes tp->t_srtt = TCPTV_SRTTBASE; 24312221Sbde tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << 2; 24411332Sswallace tp->t_rttmin = TCPTV_MIN; 24511332Sswallace TCPT_RANGESET(tp->t_rxtcur, 24611332Sswallace ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1, 24712221Sbde TCPTV_MIN, TCPTV_REXMTMAX); 24882749Sdillon tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 24982749Sdillon tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 25082749Sdillon inp->inp_ip.ip_ttl = ip_defttl; 2511541Srgrimes inp->inp_ppcb = (caddr_t)tp; 2521549Srgrimes return (tp); 25393580Sjhb} 2541541Srgrimes 2551541Srgrimes/* 25692987Sjhb * Drop a TCP connection, reporting 257130344Sphk * the specified error. If connection is synchronized, 25892987Sjhb * then send a RST to peer. 2591541Srgrimes */ 2601541Srgrimesstruct tcpcb * 2611541Srgrimestcp_drop(tp, errno) 2621541Srgrimes register struct tcpcb *tp; 2631541Srgrimes int errno; 2641541Srgrimes{ 2651541Srgrimes struct socket *so = tp->t_inpcb->inp_socket; 2661541Srgrimes 2671541Srgrimes if (TCPS_HAVERCVDSYN(tp->t_state)) { 26812221Sbde tp->t_state = TCPS_CLOSED; 26911332Sswallace (void) tcp_output(tp); 27011332Sswallace tcpstat.tcps_drops++; 27111332Sswallace } else 27212221Sbde tcpstat.tcps_conndrops++; 27382749Sdillon if (errno == ETIMEDOUT && tp->t_softerror) 27482749Sdillon errno = tp->t_softerror; 27582749Sdillon so->so_error = errno; 2761541Srgrimes return (tcp_close(tp)); 2771549Srgrimes} 27893580Sjhb 2791541Srgrimes/* 2801541Srgrimes * Close a TCP control block: 28192987Sjhb * discard all space held by the tcp 2821541Srgrimes * discard internet protocol block 2831541Srgrimes * wake up any sleepers 2841541Srgrimes */ 28512221Sbdestruct tcpcb * 2861541Srgrimestcp_close(tp) 2871541Srgrimes register struct tcpcb *tp; 2881541Srgrimes{ 2891541Srgrimes register struct tcpiphdr *t; 29012221Sbde struct inpcb *inp = tp->t_inpcb; 29182749Sdillon struct socket *so = inp->inp_socket; 29282749Sdillon register struct mbuf *m; 29382749Sdillon#ifdef RTV_RTT 2941549Srgrimes register struct rtentry *rt; 29593580Sjhb 2961541Srgrimes /* 29782749Sdillon * If we sent enough data to get some meaningful characteristics, 29877183Srwatson * save them in the routing entry. 'Enough' is arbitrarily 29987218Srwatson * defined as the sendpipesize (default 4K) * 16. This would 3001541Srgrimes * give us 16 rtt samples assuming we only get one sample per 30192987Sjhb * window (the usual case on a long haul net). 16 samples is 3021541Srgrimes * enough for the srtt filter to converge to within 5% of the correct 30383366Sjulian * value; fewer samples and we could save a very bogus rtt. 30492987Sjhb * 3051541Srgrimes * Don't update the default route's characteristics and don't 30692987Sjhb * update anything that the user "locked". 30792987Sjhb */ 30877183Srwatson if (SEQ_LT(tp->iss + so->so_snd.sb_hiwat * 16, tp->snd_max) && 30999009Salfred (rt = inp->inp_route.ro_rt) && 31093264Sdillon ((struct sockaddr_in *)rt_key(rt))->sin_addr.s_addr != INADDR_ANY) { 31193557Sjhb register u_long i = 0; 31293264Sdillon 3131541Srgrimes if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { 3141541Srgrimes i = tp->t_srtt * 31512221Sbde (RTM_RTTUNIT / (PR_SLOWHZ * TCP_RTT_SCALE)); 31612207Sbde if (rt->rt_rmx.rmx_rtt && i) 31711332Sswallace /* 31811332Sswallace * filter this update to half the old & half 31912221Sbde * the new values, converting scale. 32082749Sdillon * See route.h and tcp_var.h for a 32182749Sdillon * description of the scaling constants. 32282749Sdillon */ 3231541Srgrimes rt->rt_rmx.rmx_rtt = 3241549Srgrimes (rt->rt_rmx.rmx_rtt + i) / 2; 32593580Sjhb else 3261541Srgrimes rt->rt_rmx.rmx_rtt = i; 32791140Stanimura } 32882749Sdillon if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) { 32983366Sjulian i = tp->t_rttvar * 33091140Stanimura (RTM_RTTUNIT / (PR_SLOWHZ * TCP_RTTVAR_SCALE)); 33191140Stanimura if (rt->rt_rmx.rmx_rttvar && i) 3321541Srgrimes rt->rt_rmx.rmx_rttvar = 33391140Stanimura (rt->rt_rmx.rmx_rttvar + i) / 2; 33491140Stanimura else 33591140Stanimura rt->rt_rmx.rmx_rttvar = i; 336111119Simp } 337111119Simp /* 33891140Stanimura * update the pipelimit (ssthresh) if it has been updated 33994859Sjhb * already or if a pipesize was specified & the threshhold 34091140Stanimura * got below half the pipesize. I.e., wait for bad news 34191140Stanimura * before we start updating, then update on both good 34291140Stanimura * and bad news. 34391140Stanimura */ 34482749Sdillon if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && 34591140Stanimura ((i = tp->snd_ssthresh) != 0) && rt->rt_rmx.rmx_ssthresh) || 34691140Stanimura i < (rt->rt_rmx.rmx_sendpipe / 2)) { 34783366Sjulian /* 34894859Sjhb * convert the limit from user data bytes to 34994859Sjhb * packets then to packet data bytes. 3501541Srgrimes */ 35191140Stanimura i = (i + tp->t_maxseg / 2) / tp->t_maxseg; 35294859Sjhb if (i < 2) 35391140Stanimura i = 2; 35495973Stanimura i *= (u_long)(tp->t_maxseg + sizeof (struct tcpiphdr)); 35595973Stanimura if (rt->rt_rmx.rmx_ssthresh) 35695973Stanimura rt->rt_rmx.rmx_ssthresh = 35795973Stanimura (rt->rt_rmx.rmx_ssthresh + i) / 2; 35891140Stanimura else 35994859Sjhb rt->rt_rmx.rmx_ssthresh = i; 3601541Srgrimes } 3611541Srgrimes } 3621541Srgrimes#endif /* RTV_RTT */ 3631541Srgrimes /* free the reassembly queue, if any */ 3641541Srgrimes t = tp->seg_next; 3651541Srgrimes while (t != (struct tcpiphdr *)tp) { 3661541Srgrimes t = (struct tcpiphdr *)t->ti_next; 3671541Srgrimes m = REASS_MBUF((struct tcpiphdr *)t->ti_prev); 3681541Srgrimes remque(t->ti_prev); 3691541Srgrimes m_freem(m); 3701541Srgrimes } 3711541Srgrimes if (tp->t_template) 3721541Srgrimes (void) m_free(dtom(tp->t_template)); 3731541Srgrimes free(tp, M_PCB); 3741541Srgrimes inp->inp_ppcb = 0; 37512221Sbde soisdisconnected(so); 3761541Srgrimes /* clobber input pcb cache if we're closing the cached connection */ 37787218Srwatson if (inp == tcp_last_inpcb) 37887218Srwatson tcp_last_inpcb = &tcb; 3791541Srgrimes in_pcbdetach(inp); 38012221Sbde tcpstat.tcps_closed++; 38182749Sdillon return ((struct tcpcb *)0); 38282749Sdillon} 38382749Sdillon 3841541Srgrimesvoid 3851549Srgrimestcp_drain() 38693580Sjhb{ 3871541Srgrimes 38883366Sjulian} 38987218Srwatson 39087218Srwatson/* 39175448Srwatson * Notify a tcp user of an asynchronous error; 39291140Stanimura * store error as soft error, but wake up user 3931541Srgrimes * (for now, won't do anything until can select for soft error). 39420677Sbde */ 39520677Sbdevoid 39691140Stanimuratcp_notify(inp, error) 39791140Stanimura struct inpcb *inp; 39891140Stanimura int error; 399111119Simp{ 40091140Stanimura register struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; 40194859Sjhb register struct socket *so = inp->inp_socket; 4021541Srgrimes 40391140Stanimura /* 40482749Sdillon * Ignore some errors if we are hooked up. 40594859Sjhb * If connection hasn't completed, has retransmitted several times, 40675893Sjhb * and receives a second error, give up now. This is better 40791140Stanimura * than waiting a long time to establish a connection that 40891140Stanimura * can never complete. 40991371Stanimura */ 41094859Sjhb if (tp->t_state == TCPS_ESTABLISHED && 41191140Stanimura (error == EHOSTUNREACH || error == ENETUNREACH || 412132568Srwatson error == EHOSTDOWN)) { 41375893Sjhb return; 41494859Sjhb } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 41575893Sjhb tp->t_softerror) 41675893Sjhb so->so_error = error; 41775893Sjhb else 41875893Sjhb tp->t_softerror = error; 41982749Sdillon wakeup((caddr_t) &so->so_timeo); 42094859Sjhb sorwakeup(so); 42175893Sjhb sowwakeup(so); 42275893Sjhb} 42375893Sjhb 42482749Sdillonvoid 42594859Sjhbtcp_ctlinput(cmd, sa, ip) 42675893Sjhb int cmd; 42791140Stanimura struct sockaddr *sa; 42891140Stanimura register struct ip *ip; 4291541Srgrimes{ 43075893Sjhb register struct tcphdr *th; 43182749Sdillon extern struct in_addr zeroin_addr; 43294859Sjhb extern u_char inetctlerrmap[]; 43375893Sjhb void (*notify) __P((struct inpcb *, int)) = tcp_notify; 43487218Srwatson 4351541Srgrimes if (cmd == PRC_QUENCH) 436117214Scognet notify = tcp_quench; 437117214Scognet else if (!PRC_IS_REDIRECT(cmd) && 438117214Scognet ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0)) 439117214Scognet return; 440117214Scognet if (ip) { 441117214Scognet th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2)); 442117214Scognet in_pcbnotify(&tcb, sa, th->th_dport, ip->ip_src, th->th_sport, 443117214Scognet cmd, notify); 44491140Stanimura } else 445117214Scognet in_pcbnotify(&tcb, sa, 0, zeroin_addr, 0, cmd, notify); 446117214Scognet} 44794859Sjhb 44875893Sjhb/* 449117214Scognet * When a source quench is received, close congestion window 450117214Scognet * to one segment. We will gradually open it again as we proceed. 45191140Stanimura */ 452117214Scognetvoid 45391140Stanimuratcp_quench(inp, errno) 45491140Stanimura struct inpcb *inp; 45591140Stanimura int errno; 45691140Stanimura{ 45782749Sdillon struct tcpcb *tp = intotcpcb(inp); 45891140Stanimura 45994859Sjhb if (tp) 46094859Sjhb tp->snd_cwnd = tp->t_maxseg; 46194859Sjhb} 46295973Stanimura 46391140Stanimura/* 46482749Sdillon * Look-up the routing entry to the peer of this inpcb. If no route 4651541Srgrimes * is found and it cannot be allocated the return NULL. This routine 4661541Srgrimes * is called by TCP routines that access the rmx structure and by tcp_mss 46724448Speter * to get the interface MTU. 46824448Speter */ 46972093Sasmodaistruct rtentry * 47024448Spetertcp_rtlookup(inp) 47124448Speter struct inpcb *inp; 47224448Speter{ 47324448Speter struct route *ro; 47424448Speter struct rtentry *rt; 47524448Speter 47624448Speter ro = &inp->inp_route; 47724448Speter rt = ro->ro_rt; 47824448Speter if (rt == NULL || !(rt->rt_flags & RTF_UP)) { 47912221Sbde /* No route yet, so try to acquire one */ 4801541Srgrimes if (inp->inp_faddr.s_addr != INADDR_ANY) { 4811541Srgrimes ro->ro_dst.sa_family = AF_INET; 4821541Srgrimes ro->ro_dst.sa_len = sizeof(ro->ro_dst); 48312221Sbde ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = 48482749Sdillon inp->inp_faddr; 48582749Sdillon rtalloc(ro); 48682749Sdillon rt = ro->ro_rt; 4871541Srgrimes } 4881549Srgrimes } 48993580Sjhb return rt; 4901541Srgrimes} 49183366Sjulian 49277183Srwatson/* 49377183Srwatson * Return a pointer to the cached information about the remote host. 49498417Salfred * The cached information is stored in the protocol specific part of 49587218Srwatson * the route metrics. 4961541Srgrimes */ 49777183Srwatsonstruct rmxp_tao * 49894619Sjhbtcp_gettaocache(inp) 49998417Salfred struct inpcb *inp; 50094619Sjhb{ 50187219Srwatson struct rtentry *rt = tcp_rtlookup(inp); 50287466Srwatson 50324448Speter /* Make sure this is a host route and is up. */ 50424448Speter if (rt == NULL || 50524448Speter (rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST)) 50687218Srwatson return NULL; 50724448Speter 50872093Sasmodai return rmx_taop(rt->rt_rmx); 50924448Speter} 51024448Speter 51124448Speter/* 51224448Speter * Clear all the TAO cache entries, called from tcp_init. 51324448Speter * 51424448Speter * XXX 51524448Speter * This routine is just an empty one, because we assume that the routing 51687218Srwatson * routing tables are initialized at the same time when TCP, so there is 51724448Speter * nothing in the cache left over. 51824448Speter */ 51924448Speterstatic void 52077183Srwatsontcp_cleartaocache(void) 52117994Sache{ } 52277183Srwatson