2 * Copyright (c) 1995, Mike Mitchell
3 * Copyright (c) 1984, 1985, 1986, 1987, 1993
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * $FreeBSD: src/sys/netipx/spx_usrreq.c,v 1.27.2.1 2001/02/22 09:44:18 bp Exp $
37 * $DragonFly: src/sys/netproto/ipx/spx_usrreq.c,v 1.20 2007/04/22 01:13:15 dillon Exp $
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/malloc.h>
46 #include <sys/protosw.h>
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/socketvar2.h>
51 #include <sys/thread2.h>
52 #include <sys/msgport2.h>
54 #include <net/route.h>
55 #include <netinet/tcp_fsm.h>
61 #include "spx_timer.h"
63 #include "spx_debug.h"
66 * SPX protocol implementation.
68 static u_short spx_iss;
69 static u_short spx_newchecks[50];
70 static int spx_hardnosed;
71 static int spx_use_delack = 0;
72 static int traceallspxs = 0;
73 static struct spx spx_savesi;
74 static struct spx_istat spx_istat;
76 /* Following was struct spxstat spxstat; */
78 #define spxstat spx_istat.newstats
81 static int spx_backoff[SPX_MAXRXTSHIFT+1] =
82 { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 };
84 static struct spxpcb *spx_close(struct spxpcb *cb);
85 static struct spxpcb *spx_disconnect(struct spxpcb *cb);
86 static struct spxpcb *spx_drop(struct spxpcb *cb, int errno);
87 static int spx_output(struct spxpcb *cb, struct mbuf *m0);
88 static int spx_reass(struct spxpcb *cb, struct spx *si, struct mbuf *si_m);
89 static void spx_setpersist(struct spxpcb *cb);
90 static void spx_template(struct spxpcb *cb);
91 static struct spxpcb *spx_timers(struct spxpcb *cb, int timer);
92 static struct spxpcb *spx_usrclosed(struct spxpcb *cb);
94 static void spx_usr_abort(netmsg_t);
95 static void spx_accept(netmsg_t);
96 static void spx_attach(netmsg_t);
97 static void spx_bind(netmsg_t);
98 static void spx_connect(netmsg_t);
99 static void spx_detach(netmsg_t);
100 static void spx_usr_disconnect(netmsg_t);
101 static void spx_listen(netmsg_t);
102 static void spx_rcvd(netmsg_t);
103 static void spx_rcvoob(netmsg_t);
104 static void spx_send(netmsg_t);
105 static void spx_shutdown(netmsg_t);
106 static void spx_sp_attach(netmsg_t);
108 struct pr_usrreqs spx_usrreqs = {
109 .pru_abort = spx_usr_abort,
110 .pru_accept = spx_accept,
111 .pru_attach = spx_attach,
112 .pru_bind = spx_bind,
113 .pru_connect = spx_connect,
114 .pru_connect2 = pr_generic_notsupp,
115 .pru_control = ipx_control,
116 .pru_detach = spx_detach,
117 .pru_disconnect = spx_usr_disconnect,
118 .pru_listen = spx_listen,
119 .pru_peeraddr = ipx_peeraddr,
120 .pru_rcvd = spx_rcvd,
121 .pru_rcvoob = spx_rcvoob,
122 .pru_send = spx_send,
123 .pru_sense = pru_sense_null,
124 .pru_shutdown = spx_shutdown,
125 .pru_sockaddr = ipx_sockaddr,
126 .pru_sosend = sosend,
127 .pru_soreceive = soreceive
130 struct pr_usrreqs spx_usrreq_sps = {
131 .pru_abort = spx_usr_abort,
132 .pru_accept = spx_accept,
133 .pru_attach = spx_sp_attach,
134 .pru_bind = spx_bind,
135 .pru_connect = spx_connect,
136 .pru_connect2 = pr_generic_notsupp,
137 .pru_control = ipx_control,
138 .pru_detach = spx_detach,
139 .pru_disconnect = spx_usr_disconnect,
140 .pru_listen = spx_listen,
141 .pru_peeraddr = ipx_peeraddr,
142 .pru_rcvd = spx_rcvd,
143 .pru_rcvoob = spx_rcvoob,
144 .pru_send = spx_send,
145 .pru_sense = pru_sense_null,
146 .pru_shutdown = spx_shutdown,
147 .pru_sockaddr = ipx_sockaddr,
148 .pru_sosend = sosend,
149 .pru_soreceive = soreceive
152 static MALLOC_DEFINE(M_SPX_Q, "ipx_spx_q", "IPX Packet Management");
158 spx_iss = 1; /* WRONG !! should fish it out of TODR */
162 spx_input(struct mbuf *m, struct ipxpcb *ipxp)
170 spxstat.spxs_rcvtotal++;
172 panic("No ipxpcb in spx_input\n");
176 cb = ipxtospxpcb(ipxp);
180 if (m->m_len < sizeof(struct spx)) {
181 if ((m = m_pullup(m, sizeof(*si))) == NULL) {
182 spxstat.spxs_rcvshort++;
186 si = mtod(m, struct spx *);
187 si->si_seq = ntohs(si->si_seq);
188 si->si_ack = ntohs(si->si_ack);
189 si->si_alo = ntohs(si->si_alo);
191 so = ipxp->ipxp_socket;
193 if (so->so_options & SO_DEBUG || traceallspxs) {
194 ostate = cb->s_state;
197 if (so->so_options & SO_ACCEPTCONN) {
198 struct spxpcb *ocb = cb;
200 so = sonewconn(so, 0);
205 * This is ugly, but ....
207 * Mark socket as temporary until we're
208 * committed to keeping it. The code at
209 * ``drop'' and ``dropwithreset'' check the
210 * flag dropsocket to see if the temporary
211 * socket created here should be discarded.
212 * We mark the socket as discardable until
213 * we're committed to it below in TCPS_LISTEN.
216 ipxp = (struct ipxpcb *)so->so_pcb;
217 ipxp->ipxp_laddr = si->si_dna;
218 cb = ipxtospxpcb(ipxp);
219 cb->s_mtu = ocb->s_mtu; /* preserve sockopts */
220 cb->s_flags = ocb->s_flags; /* preserve sockopts */
221 cb->s_flags2 = ocb->s_flags2; /* preserve sockopts */
222 cb->s_state = TCPS_LISTEN;
226 * Packet received on connection.
227 * reset idle time and keep-alive timer;
230 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
232 switch (cb->s_state) {
235 struct sockaddr_ipx *sipx, ssipx;
236 struct ipx_addr laddr;
239 * If somebody here was carying on a conversation
240 * and went away, and his pen pal thinks he can
241 * still talk, we get the misdirected packet.
243 if (spx_hardnosed && (si->si_did != 0 || si->si_seq != 0)) {
248 bzero(sipx, sizeof *sipx);
249 sipx->sipx_len = sizeof(*sipx);
250 sipx->sipx_family = AF_IPX;
251 sipx->sipx_addr = si->si_sna;
252 laddr = ipxp->ipxp_laddr;
253 if (ipx_nullhost(laddr))
254 ipxp->ipxp_laddr = si->si_dna;
255 if (ipx_pcbconnect(ipxp, (struct sockaddr *)sipx, &thread0)) {
256 ipxp->ipxp_laddr = laddr;
261 dropsocket = 0; /* committed to socket */
262 cb->s_did = si->si_sid;
263 cb->s_rack = si->si_ack;
264 cb->s_ralo = si->si_alo;
265 #define THREEWAYSHAKE
267 cb->s_state = TCPS_SYN_RECEIVED;
268 cb->s_force = 1 + SPXT_KEEP;
269 spxstat.spxs_accepts++;
270 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
274 * This state means that we have heard a response
275 * to our acceptance of their connection
276 * It is probably logically unnecessary in this
279 case TCPS_SYN_RECEIVED: {
280 if (si->si_did != cb->s_sid) {
285 ipxp->ipxp_fport = si->si_sport;
286 cb->s_timer[SPXT_REXMT] = 0;
287 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
289 cb->s_state = TCPS_ESTABLISHED;
290 spxstat.spxs_accepts++;
295 * This state means that we have gotten a response
296 * to our attempt to establish a connection.
297 * We fill in the data from the other side,
298 * telling us which port to respond to, instead of the well-
299 * known one we might have sent to in the first place.
300 * We also require that this is a response to our
304 if (si->si_did != cb->s_sid) {
308 spxstat.spxs_connects++;
309 cb->s_did = si->si_sid;
310 cb->s_rack = si->si_ack;
311 cb->s_ralo = si->si_alo;
312 cb->s_dport = ipxp->ipxp_fport = si->si_sport;
313 cb->s_timer[SPXT_REXMT] = 0;
314 cb->s_flags |= SF_ACKNOW;
316 cb->s_state = TCPS_ESTABLISHED;
317 /* Use roundtrip time of connection request for initial rtt */
319 cb->s_srtt = cb->s_rtt << 3;
320 cb->s_rttvar = cb->s_rtt << 1;
321 SPXT_RANGESET(cb->s_rxtcur,
322 ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
323 SPXTV_MIN, SPXTV_REXMTMAX);
327 if (so->so_options & SO_DEBUG || traceallspxs)
328 spx_trace(SA_INPUT, (u_char)ostate, cb, &spx_savesi, 0);
330 m->m_len -= sizeof(struct ipx);
331 m->m_pkthdr.len -= sizeof(struct ipx);
332 m->m_data += sizeof(struct ipx);
334 if (spx_reass(cb, si, m)) {
337 if (cb->s_force || (cb->s_flags & (SF_ACKNOW|SF_WIN|SF_RXT)))
338 spx_output(cb, NULL);
339 cb->s_flags &= ~(SF_WIN|SF_RXT);
345 si->si_seq = ntohs(si->si_seq);
346 si->si_ack = ntohs(si->si_ack);
347 si->si_alo = ntohs(si->si_alo);
349 if (cb->s_ipxpcb->ipxp_socket->so_options & SO_DEBUG || traceallspxs)
350 spx_trace(SA_DROP, (u_char)ostate, cb, &spx_savesi, 0);
355 if (cb == 0 || cb->s_ipxpcb->ipxp_socket->so_options & SO_DEBUG ||
357 spx_trace(SA_DROP, (u_char)ostate, cb, &spx_savesi, 0);
361 static int spxrexmtthresh = 3;
364 * This is structurally similar to the tcp reassembly routine
365 * but its function is somewhat different: It merely queues
366 * packets up, and suppresses duplicates.
369 spx_reass(struct spxpcb *cb, struct spx *si, struct mbuf *si_m)
371 struct spx_q *q, *nq, *q_temp;
373 struct socket *so = cb->s_ipxpcb->ipxp_socket;
374 char packetp = cb->s_flags & SF_HI;
381 * Update our news from them.
383 if (si->si_cc & SPX_SA)
384 cb->s_flags |= (spx_use_delack ? SF_DELACK : SF_ACKNOW);
385 if (SSEQ_GT(si->si_alo, cb->s_ralo))
386 cb->s_flags |= SF_WIN;
387 if (SSEQ_LEQ(si->si_ack, cb->s_rack)) {
388 if ((si->si_cc & SPX_SP) && cb->s_rack != (cb->s_smax + 1)) {
389 spxstat.spxs_rcvdupack++;
391 * If this is a completely duplicate ack
392 * and other conditions hold, we assume
393 * a packet has been dropped and retransmit
394 * it exactly as in tcp_input().
396 if (si->si_ack != cb->s_rack ||
397 si->si_alo != cb->s_ralo)
399 else if (++cb->s_dupacks == spxrexmtthresh) {
400 u_short onxt = cb->s_snxt;
401 int cwnd = cb->s_cwnd;
403 cb->s_snxt = si->si_ack;
405 cb->s_force = 1 + SPXT_REXMT;
406 spx_output(cb, NULL);
407 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
409 if (cwnd >= 4 * CUNIT)
410 cb->s_cwnd = cwnd / 2;
411 if (SSEQ_GT(onxt, cb->s_snxt))
421 * If our correspondent acknowledges data we haven't sent
422 * TCP would drop the packet after acking. We'll be a little
425 if (SSEQ_GT(si->si_ack, (cb->s_smax + 1))) {
426 spxstat.spxs_rcvacktoomuch++;
427 si->si_ack = cb->s_smax + 1;
429 spxstat.spxs_rcvackpack++;
431 * If transmit timer is running and timed sequence
432 * number was acked, update smoothed round trip time.
433 * See discussion of algorithm in tcp_input.c
435 if (cb->s_rtt && SSEQ_GT(si->si_ack, cb->s_rtseq)) {
436 spxstat.spxs_rttupdated++;
437 if (cb->s_srtt != 0) {
439 delta = cb->s_rtt - (cb->s_srtt >> 3);
440 if ((cb->s_srtt += delta) <= 0)
444 delta -= (cb->s_rttvar >> 2);
445 if ((cb->s_rttvar += delta) <= 0)
449 * No rtt measurement yet
451 cb->s_srtt = cb->s_rtt << 3;
452 cb->s_rttvar = cb->s_rtt << 1;
456 SPXT_RANGESET(cb->s_rxtcur,
457 ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
458 SPXTV_MIN, SPXTV_REXMTMAX);
461 * If all outstanding data is acked, stop retransmit
462 * timer and remember to restart (more output or persist).
463 * If there is more data to be acked, restart retransmit
464 * timer, using current (possibly backed-off) value;
466 if (si->si_ack == cb->s_smax + 1) {
467 cb->s_timer[SPXT_REXMT] = 0;
468 cb->s_flags |= SF_RXT;
469 } else if (cb->s_timer[SPXT_PERSIST] == 0)
470 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
472 * When new data is acked, open the congestion window.
473 * If the window gives us less than ssthresh packets
474 * in flight, open exponentially (maxseg at a time).
475 * Otherwise open linearly (maxseg^2 / cwnd at a time).
478 if (cb->s_cwnd > cb->s_ssthresh)
479 incr = max(incr * incr / cb->s_cwnd, 1);
480 cb->s_cwnd = min(cb->s_cwnd + incr, cb->s_cwmx);
482 * Trim Acked data from output queue.
484 while ((m = so->so_snd.ssb_mb) != NULL) {
485 if (SSEQ_LT((mtod(m, struct spx *))->si_seq, si->si_ack))
486 sbdroprecord(&so->so_snd.sb);
491 cb->s_rack = si->si_ack;
493 if (SSEQ_LT(cb->s_snxt, cb->s_rack))
494 cb->s_snxt = cb->s_rack;
495 if (SSEQ_LT(cb->s_swl1, si->si_seq) || ((cb->s_swl1 == si->si_seq &&
496 (SSEQ_LT(cb->s_swl2, si->si_ack))) ||
497 (cb->s_swl2 == si->si_ack && SSEQ_LT(cb->s_ralo, si->si_alo)))) {
498 /* keep track of pure window updates */
499 if ((si->si_cc & SPX_SP) && cb->s_swl2 == si->si_ack
500 && SSEQ_LT(cb->s_ralo, si->si_alo)) {
501 spxstat.spxs_rcvwinupd++;
502 spxstat.spxs_rcvdupack--;
504 cb->s_ralo = si->si_alo;
505 cb->s_swl1 = si->si_seq;
506 cb->s_swl2 = si->si_ack;
507 cb->s_swnd = (1 + si->si_alo - si->si_ack);
508 if (cb->s_swnd > cb->s_smxw)
509 cb->s_smxw = cb->s_swnd;
510 cb->s_flags |= SF_WIN;
513 * If this packet number is higher than that which
514 * we have allocated refuse it, unless urgent
516 if (SSEQ_GT(si->si_seq, cb->s_alo)) {
517 if (si->si_cc & SPX_SP) {
518 spxstat.spxs_rcvwinprobe++;
521 spxstat.spxs_rcvpackafterwin++;
522 if (si->si_cc & SPX_OB) {
523 if (SSEQ_GT(si->si_seq, cb->s_alo + 60)) {
526 } /* else queue this packet; */
528 /*register struct socket *so = cb->s_ipxpcb->ipxp_socket;
529 if (so->so_state && SS_NOFDREF) {
539 * If this is a system packet, we don't need to
540 * queue it up, and won't update acknowledge #
542 if (si->si_cc & SPX_SP) {
546 * We have already seen this packet, so drop.
548 if (SSEQ_LT(si->si_seq, cb->s_ack)) {
550 spxstat.spxs_rcvduppack++;
551 if (si->si_seq == cb->s_ack - 1)
556 * Loop through all packets queued up to insert in
557 * appropriate sequence.
559 LIST_FOREACH(q, &cb->s_q, sq_entry) {
560 if (si->si_seq == SI(q)->si_seq) {
561 spxstat.spxs_rcvduppack++;
564 if (SSEQ_LT(si->si_seq, SI(q)->si_seq)) {
565 spxstat.spxs_rcvoopack++;
569 nq = kmalloc(sizeof(struct spx_q), M_SPX_Q, M_INTNOWAIT);
575 LIST_INSERT_HEAD(&cb->s_q, nq, sq_entry);
577 LIST_INSERT_BEFORE(q, nq, sq_entry);
580 * If this packet is urgent, inform process
582 if (si->si_cc & SPX_OB) {
583 cb->s_iobc = ((char *)si)[1 + sizeof(*si)];
585 cb->s_oobflags |= SF_IOOB;
588 #define SPINC sizeof(struct spxhdr)
590 * Loop through all packets queued up to update acknowledge
591 * number, and present all acknowledged data to user;
592 * If in packet interface mode, show packet headers.
594 LIST_FOREACH_MUTABLE(q, &cb->s_q, sq_entry, q_temp) {
595 if (SI(q)->si_seq == cb->s_ack) {
598 if (SI(q)->si_cc & SPX_OB) {
599 cb->s_oobflags &= ~SF_IOOB;
600 if (so->so_rcv.ssb_cc)
601 so->so_oobmark = so->so_rcv.ssb_cc;
603 sosetstate(so, SS_RCVATMARK);
605 LIST_REMOVE(q, sq_entry);
608 spxstat.spxs_rcvpack++;
610 if (cb->s_flags2 & SF_NEWCALL) {
611 struct spxhdr *sp = mtod(m, struct spxhdr *);
612 u_char dt = sp->spx_dt;
614 if (dt != cb->s_rhdr.spx_dt) {
616 m_getclr(MB_DONTWAIT, MT_CONTROL);
621 cb->s_rhdr.spx_dt = dt;
622 mm->m_len = 5; /*XXX*/
625 *(u_char *)(&s[2]) = dt;
626 sbappend(&so->so_rcv.sb, mm);
629 if (sp->spx_cc & SPX_OB) {
630 m_chtype(m, MT_OOBDATA);
633 soclrstate(so, SS_RCVATMARK);
638 m->m_pkthdr.len -= SPINC;
640 if ((sp->spx_cc & SPX_EM) || packetp) {
641 sbappendrecord(&so->so_rcv.sb, m);
644 sbappend(&so->so_rcv.sb, m);
648 sbappendrecord(&so->so_rcv.sb, m);
650 cb->s_rhdr = *mtod(m, struct spxhdr *);
653 m->m_pkthdr.len -= SPINC;
654 sbappend(&so->so_rcv.sb, m);
665 spx_ctlinput(netmsg_t msg)
667 /*struct socket *so = msg->base.nm_so;*/
668 int cmd = msg->ctlinput.nm_cmd;
669 struct sockaddr *arg_as_sa = msg->ctlinput.nm_arg;
670 caddr_t arg = (/* XXX */ caddr_t)arg_as_sa;
672 struct sockaddr_ipx *sipx;
674 if (cmd < 0 || cmd > PRC_NCMDS)
682 case PRC_HOSTUNREACH:
683 sipx = (struct sockaddr_ipx *)arg;
684 if (sipx->sipx_family != AF_IPX)
686 na = &sipx->sipx_addr;
692 lwkt_replymsg(&msg->lmsg, 0);
696 spx_output(struct spxpcb *cb, struct mbuf *m0)
698 struct socket *so = cb->s_ipxpcb->ipxp_socket;
699 struct mbuf *m = NULL;
700 struct spx *si = NULL;
701 struct signalsockbuf *ssb = &so->so_snd;
702 int len = 0, win, rcv_win;
703 short span, off, recordp = 0;
705 int error = 0, sendalot;
715 * Make sure that packet isn't too big.
717 for (m = m0; m != NULL; m = m->m_next) {
720 if (m->m_flags & M_EOR)
723 datalen = (cb->s_flags & SF_HO) ?
724 len - sizeof(struct spxhdr) : len;
726 if (cb->s_flags & SF_PI) {
730 int oldEM = cb->s_cc & SPX_EM;
735 * Here we are only being called
736 * from usrreq(), so it is OK to
739 m = m_copym(m0, 0, mtu, MB_WAIT);
740 if (cb->s_flags & SF_NEWCALL) {
744 mm->m_flags &= ~M_EOR;
748 error = spx_output(cb, m);
761 * Force length even, by adding a "garbage byte" if
766 if (M_TRAILINGSPACE(m) >= 1)
769 struct mbuf *m1 = m_get(MB_DONTWAIT, MT_DATA);
776 *(mtod(m1, u_char *)) = 0;
780 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
786 * Fill in mbuf with extended SP header
787 * and addresses and length put into network format.
789 MH_ALIGN(m, sizeof(struct spx));
790 m->m_len = sizeof(struct spx);
792 si = mtod(m, struct spx *);
793 si->si_i = *cb->s_ipx;
794 si->si_s = cb->s_shdr;
795 if ((cb->s_flags & SF_PI) && (cb->s_flags & SF_HO)) {
797 if (m0->m_len < sizeof(*sh)) {
798 if((m0 = m_pullup(m0, sizeof(*sh))) == NULL) {
805 sh = mtod(m0, struct spxhdr *);
806 si->si_dt = sh->spx_dt;
807 si->si_cc |= sh->spx_cc & SPX_EM;
808 m0->m_len -= sizeof(*sh);
809 m0->m_data += sizeof(*sh);
813 if ((cb->s_flags2 & SF_NEWCALL) && recordp) {
817 if (cb->s_oobflags & SF_SOOB) {
820 * make sure OB packets convey exactly 1 byte.
821 * If the packet is 1 byte or larger, we
822 * have already guaranted there to be at least
823 * one garbage byte for the checksum, and
824 * extra bytes shouldn't hurt!
826 if (len > sizeof(*si)) {
828 len = (1 + sizeof(*si));
831 si->si_len = htons((u_short)len);
832 m->m_pkthdr.len = ((len - 1) | 1) + 1;
834 * queue stuff up for output
836 sbappendrecord(&ssb->sb, m);
840 idle = (cb->s_smax == (cb->s_rack - 1));
844 off = cb->s_snxt - cb->s_rack;
845 win = min(cb->s_swnd, (cb->s_cwnd / CUNIT));
848 * If in persist timeout with window of 0, send a probe.
849 * Otherwise, if window is small but nonzero
850 * and timer expired, send what we can and go into
853 if (cb->s_force == 1 + SPXT_PERSIST) {
855 cb->s_timer[SPXT_PERSIST] = 0;
859 span = cb->s_seq - cb->s_rack;
860 len = min(span, win) - off;
864 * Window shrank after we went into it.
865 * If window shrank to 0, cancel pending
866 * restransmission and pull s_snxt back
867 * to (closed) window. We will enter persist
868 * state below. If the widndow didn't close completely,
869 * just wait for an ACK.
873 cb->s_timer[SPXT_REXMT] = 0;
874 cb->s_snxt = cb->s_rack;
879 rcv_win = ssb_space(&so->so_rcv);
882 * Send if we owe peer an ACK.
884 if (cb->s_oobflags & SF_SOOB) {
886 * must transmit this out of band packet
888 cb->s_oobflags &= ~ SF_SOOB;
890 spxstat.spxs_sndurg++;
893 if (cb->s_flags & SF_ACKNOW)
895 if (cb->s_state < TCPS_ESTABLISHED)
898 * Silly window can't happen in spx.
899 * Code from tcp deleted.
904 * Compare available window to amount of window
905 * known to peer (as advertised window less
906 * next expected input.) If the difference is at least two
907 * packets or at least 35% of the mximum possible window,
908 * then want to send a window update to peer.
911 u_short delta = 1 + cb->s_alo - cb->s_ack;
912 int adv = rcv_win - (delta * cb->s_mtu);
914 if ((so->so_rcv.ssb_cc == 0 && adv >= (2 * cb->s_mtu)) ||
915 (100 * adv / so->so_rcv.ssb_hiwat >= 35)) {
916 spxstat.spxs_sndwinup++;
917 cb->s_flags |= SF_ACKNOW;
923 * Many comments from tcp_output.c are appropriate here
925 * If send window is too small, there is data to transmit, and no
926 * retransmit or persist is pending, then go to persist state.
927 * If nothing happens soon, send when timer expires:
928 * if window is nonzero, transmit what we can,
929 * otherwise send a probe.
931 if (so->so_snd.ssb_cc && cb->s_timer[SPXT_REXMT] == 0 &&
932 cb->s_timer[SPXT_PERSIST] == 0) {
937 * No reason to send a packet, just return.
944 * Find requested packet.
948 cb->s_want = cb->s_snxt;
949 for (m = ssb->ssb_mb; m != NULL; m = m->m_nextpkt) {
950 si = mtod(m, struct spx *);
951 if (SSEQ_LEQ(cb->s_snxt, si->si_seq))
956 if (si->si_seq == cb->s_snxt)
959 spxstat.spxs_sndvoid++, si = 0;
967 alo = cb->s_ack - 1 + (rcv_win / ((short)cb->s_mtu));
968 if (SSEQ_LT(alo, cb->s_alo))
973 * must make a copy of this packet for
974 * ipx_output to monkey with
976 m = m_copy(m, 0, (int)M_COPYALL);
980 si = mtod(m, struct spx *);
981 if (SSEQ_LT(si->si_seq, cb->s_smax))
982 spxstat.spxs_sndrexmitpack++;
984 spxstat.spxs_sndpack++;
985 } else if (cb->s_force || cb->s_flags & SF_ACKNOW) {
987 * Must send an acknowledgement or a probe
990 spxstat.spxs_sndprobe++;
991 if (cb->s_flags & SF_ACKNOW)
992 spxstat.spxs_sndacks++;
993 m = m_gethdr(MB_DONTWAIT, MT_HEADER);
997 * Fill in mbuf with extended SP header
998 * and addresses and length put into network format.
1000 MH_ALIGN(m, sizeof(struct spx));
1001 m->m_len = sizeof(*si);
1002 m->m_pkthdr.len = sizeof(*si);
1003 si = mtod(m, struct spx *);
1004 si->si_i = *cb->s_ipx;
1005 si->si_s = cb->s_shdr;
1006 si->si_seq = cb->s_smax + 1;
1007 si->si_len = htons(sizeof(*si));
1008 si->si_cc |= SPX_SP;
1011 if (so->so_options & SO_DEBUG || traceallspxs)
1012 spx_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
1016 * Stuff checksum and output datagram.
1018 if ((si->si_cc & SPX_SP) == 0) {
1019 if (cb->s_force != (1 + SPXT_PERSIST) ||
1020 cb->s_timer[SPXT_PERSIST] == 0) {
1022 * If this is a new packet and we are not currently
1023 * timing anything, time this one.
1025 if (SSEQ_LT(cb->s_smax, si->si_seq)) {
1026 cb->s_smax = si->si_seq;
1027 if (cb->s_rtt == 0) {
1028 spxstat.spxs_segstimed++;
1029 cb->s_rtseq = si->si_seq;
1034 * Set rexmt timer if not currently set,
1035 * Initial value for retransmit timer is smoothed
1036 * round-trip time + 2 * round-trip time variance.
1037 * Initialize shift counter which is used for backoff
1038 * of retransmit time.
1040 if (cb->s_timer[SPXT_REXMT] == 0 &&
1041 cb->s_snxt != cb->s_rack) {
1042 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
1043 if (cb->s_timer[SPXT_PERSIST]) {
1044 cb->s_timer[SPXT_PERSIST] = 0;
1048 } else if (SSEQ_LT(cb->s_smax, si->si_seq)) {
1049 cb->s_smax = si->si_seq;
1051 } else if (cb->s_state < TCPS_ESTABLISHED) {
1053 cb->s_rtt = 1; /* Time initial handshake */
1054 if (cb->s_timer[SPXT_REXMT] == 0)
1055 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
1059 * Do not request acks when we ack their data packets or
1060 * when we do a gratuitous window update.
1062 if (((si->si_cc & SPX_SP) == 0) || cb->s_force)
1063 si->si_cc |= SPX_SA;
1064 si->si_seq = htons(si->si_seq);
1065 si->si_alo = htons(alo);
1066 si->si_ack = htons(cb->s_ack);
1069 si->si_sum = ipx_cksum(m, ntohs(si->si_len));
1071 si->si_sum = 0xffff;
1074 if (so->so_options & SO_DEBUG || traceallspxs)
1075 spx_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
1077 if (so->so_options & SO_DONTROUTE)
1078 error = ipx_outputfl(m, NULL, IPX_ROUTETOIF);
1080 error = ipx_outputfl(m, &cb->s_ipxpcb->ipxp_route, 0);
1085 spxstat.spxs_sndtotal++;
1087 * Data sent (as far as we can tell).
1088 * If this advertises a larger window than any other segment,
1089 * then remember the size of the advertized window.
1090 * Any pending ACK has now been sent.
1093 cb->s_flags &= ~(SF_ACKNOW|SF_DELACK);
1094 if (SSEQ_GT(alo, cb->s_alo))
1102 static int spx_do_persist_panics = 0;
1105 spx_setpersist(struct spxpcb *cb)
1107 int t = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1;
1109 if (cb->s_timer[SPXT_REXMT] && spx_do_persist_panics)
1110 panic("spx_output REXMT");
1112 * Start/restart persistance timer.
1114 SPXT_RANGESET(cb->s_timer[SPXT_PERSIST],
1115 t*spx_backoff[cb->s_rxtshift],
1116 SPXTV_PERSMIN, SPXTV_PERSMAX);
1117 if (cb->s_rxtshift < SPX_MAXRXTSHIFT)
1122 spx_ctloutput(netmsg_t msg)
1124 struct socket *so = msg->base.nm_so;
1125 struct ipxpcb *ipxp = sotoipxpcb(so);
1126 struct sockopt *sopt = msg->ctloutput.nm_sopt;
1135 if (sopt->sopt_level != IPXPROTO_SPX) {
1136 /* This will have to be changed when we do more general
1137 stacking of protocols */
1139 /* msg now invalid */
1146 cb = ipxtospxpcb(ipxp);
1148 switch (sopt->sopt_dir) {
1150 switch (sopt->sopt_name) {
1151 case SO_HEADERS_ON_INPUT:
1155 case SO_HEADERS_ON_OUTPUT:
1158 soptval = cb->s_flags & mask;
1159 error = sooptcopyout(sopt, &soptval, sizeof soptval);
1163 usoptval = cb->s_mtu;
1164 error = sooptcopyout(sopt, &usoptval, sizeof usoptval);
1167 case SO_LAST_HEADER:
1168 error = sooptcopyout(sopt, &cb->s_rhdr,
1172 case SO_DEFAULT_HEADERS:
1173 error = sooptcopyout(sopt, &cb->s_shdr,
1178 error = ENOPROTOOPT;
1183 switch (sopt->sopt_name) {
1184 /* XXX why are these shorts on get and ints on set?
1185 that doesn't make any sense... */
1186 case SO_HEADERS_ON_INPUT:
1190 case SO_HEADERS_ON_OUTPUT:
1193 error = sooptcopyin(sopt, &optval, sizeof optval,
1198 if (cb->s_flags & SF_PI) {
1200 cb->s_flags |= mask;
1202 cb->s_flags &= ~mask;
1203 } else error = EINVAL;
1207 error = sooptcopyin(sopt, &usoptval, sizeof usoptval,
1211 cb->s_mtu = usoptval;
1216 error = sooptcopyin(sopt, &optval, sizeof optval,
1221 cb->s_flags2 |= SF_NEWCALL;
1224 cb->s_flags2 &= ~SF_NEWCALL;
1230 case SO_DEFAULT_HEADERS:
1234 error = sooptcopyin(sopt, &sp, sizeof sp,
1238 cb->s_dt = sp.spx_dt;
1239 cb->s_cc = sp.spx_cc & SPX_EM;
1244 error = ENOPROTOOPT;
1249 lwkt_replymsg(&msg->lmsg, error);
1253 * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort()
1254 * will sofree() it when we return.
1257 spx_usr_abort(netmsg_t msg)
1259 struct socket *so = msg->base.nm_so;
1260 struct ipxpcb *ipxp;
1263 ipxp = sotoipxpcb(so);
1264 cb = ipxtospxpcb(ipxp);
1266 spx_drop(cb, ECONNABORTED);
1268 lwkt_replymsg(&msg->lmsg, 0);
1272 * Accept a connection. Essentially all the work is
1273 * done at higher levels; just return the address
1274 * of the peer, storing through addr.
1277 spx_accept(netmsg_t msg)
1279 struct socket *so = msg->base.nm_so;
1280 struct sockaddr **nam = msg->accept.nm_nam;
1281 struct ipxpcb *ipxp;
1282 struct sockaddr_ipx *sipx, ssipx;
1284 ipxp = sotoipxpcb(so);
1286 bzero(sipx, sizeof *sipx);
1287 sipx->sipx_len = sizeof *sipx;
1288 sipx->sipx_family = AF_IPX;
1289 sipx->sipx_addr = ipxp->ipxp_faddr;
1290 *nam = dup_sockaddr((struct sockaddr *)sipx);
1292 lwkt_replymsg(&msg->lmsg, 0);
1296 spx_attach_oncpu(struct socket *so, int proto, struct pru_attach_info *ai)
1298 struct ipxpcb *ipxp;
1301 struct signalsockbuf *ssb;
1304 ipxp = sotoipxpcb(so);
1305 cb = ipxtospxpcb(ipxp);
1310 goto spx_attach_end;
1312 error = ipx_pcballoc(so, &ipxpcb_list);
1314 goto spx_attach_end;
1315 if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) {
1316 error = soreserve(so, (u_long) 3072, (u_long) 3072,
1319 goto spx_attach_end;
1321 ipxp = sotoipxpcb(so);
1323 MALLOC(cb, struct spxpcb *, sizeof *cb, M_PCB, M_INTWAIT | M_ZERO);
1326 mm = m_getclr(MB_DONTWAIT, MT_HEADER);
1330 goto spx_attach_end;
1333 cb->s_ipx = mtod(mm, struct ipx *);
1334 cb->s_state = TCPS_LISTEN;
1337 LIST_INIT(&cb->s_q);
1338 cb->s_ipxpcb = ipxp;
1339 cb->s_mtu = 576 - sizeof(struct spx);
1340 cb->s_cwnd = ssb_space(ssb) * CUNIT / cb->s_mtu;
1341 cb->s_ssthresh = cb->s_cwnd;
1342 cb->s_cwmx = ssb_space(ssb) * CUNIT / (2 * sizeof(struct spx));
1343 /* Above is recomputed when connecting to account
1344 for changed buffering or mtu's */
1345 cb->s_rtt = SPXTV_SRTTBASE;
1346 cb->s_rttvar = SPXTV_SRTTDFLT << 2;
1347 SPXT_RANGESET(cb->s_rxtcur,
1348 ((SPXTV_SRTTBASE >> 2) + (SPXTV_SRTTDFLT << 2)) >> 1,
1349 SPXTV_MIN, SPXTV_REXMTMAX);
1350 ipxp->ipxp_pcb = (caddr_t)cb;
1357 spx_attach(netmsg_t msg)
1361 error = spx_attach_oncpu(msg->base.nm_so,
1362 msg->attach.nm_proto,
1364 lwkt_replymsg(&msg->lmsg, error);
1369 spx_bind(netmsg_t msg)
1371 struct socket *so = msg->base.nm_so;
1372 struct ipxpcb *ipxp;
1375 ipxp = sotoipxpcb(so);
1377 error = ipx_pcbbind(ipxp, msg->bind.nm_nam, msg->bind.nm_td);
1378 lwkt_replymsg(&msg->lmsg, error);
1382 * Initiate connection to peer.
1383 * Enter SYN_SENT state, and mark socket as connecting.
1384 * Start keep-alive timer, setup prototype header,
1385 * Send initial system packet requesting connection.
1388 spx_connect(netmsg_t msg)
1390 struct socket *so = msg->base.nm_so;
1391 struct sockaddr *nam = msg->connect.nm_nam;
1392 struct thread *td = msg->connect.nm_td;
1393 struct ipxpcb *ipxp;
1397 ipxp = sotoipxpcb(so);
1398 cb = ipxtospxpcb(ipxp);
1401 if (ipxp->ipxp_lport == 0) {
1402 error = ipx_pcbbind(ipxp, NULL, td);
1404 goto spx_connect_end;
1406 error = ipx_pcbconnect(ipxp, nam, td);
1408 goto spx_connect_end;
1410 spxstat.spxs_connattempt++;
1411 cb->s_state = TCPS_SYN_SENT;
1414 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
1415 cb->s_force = 1 + SPXTV_KEEP;
1417 * Other party is required to respond to
1418 * the port I send from, but he is not
1419 * required to answer from where I am sending to,
1420 * so allow wildcarding.
1421 * original port I am sending to is still saved in
1424 ipxp->ipxp_fport = 0;
1425 error = spx_output(cb, NULL);
1428 lwkt_replymsg(&msg->lmsg, error);
1432 spx_detach(netmsg_t msg)
1434 struct socket *so = msg->base.nm_so;
1435 struct ipxpcb *ipxp;
1439 ipxp = sotoipxpcb(so);
1440 cb = ipxtospxpcb(ipxp);
1444 if (cb->s_state > TCPS_LISTEN)
1453 lwkt_replymsg(&msg->lmsg, error);
1457 * We may decide later to implement connection closing
1458 * handshaking at the spx level optionally.
1459 * here is the hook to do it:
1462 spx_usr_disconnect(netmsg_t msg)
1464 struct socket *so = msg->base.nm_so;
1465 struct ipxpcb *ipxp;
1468 ipxp = sotoipxpcb(so);
1469 cb = ipxtospxpcb(ipxp);
1475 lwkt_replymsg(&msg->lmsg, 0);
1479 spx_listen(netmsg_t msg)
1481 struct socket *so = msg->base.nm_so;
1482 struct ipxpcb *ipxp;
1487 ipxp = sotoipxpcb(so);
1488 cb = ipxtospxpcb(ipxp);
1490 if (ipxp->ipxp_lport == 0)
1491 error = ipx_pcbbind(ipxp, NULL, msg->listen.nm_td);
1493 cb->s_state = TCPS_LISTEN;
1494 lwkt_replymsg(&msg->lmsg, error);
1498 * After a receive, possibly send acknowledgment
1499 * updating allocation.
1502 spx_rcvd(netmsg_t msg)
1504 struct socket *so = msg->base.nm_so;
1505 struct ipxpcb *ipxp;
1508 ipxp = sotoipxpcb(so);
1509 cb = ipxtospxpcb(ipxp);
1512 cb->s_flags |= SF_RVD;
1513 spx_output(cb, NULL);
1514 cb->s_flags &= ~SF_RVD;
1517 lwkt_replymsg(&msg->lmsg, 0);
1521 spx_rcvoob(netmsg_t msg)
1523 struct mbuf *m = msg->rcvoob.nm_m;
1524 struct socket *so = msg->base.nm_so;
1525 struct ipxpcb *ipxp;
1529 ipxp = sotoipxpcb(so);
1530 cb = ipxtospxpcb(ipxp);
1532 if ((cb->s_oobflags & SF_IOOB) || so->so_oobmark ||
1533 (so->so_state & SS_RCVATMARK)) {
1535 *mtod(m, caddr_t) = cb->s_iobc;
1540 lwkt_replymsg(&msg->lmsg, error);
1544 spx_send(netmsg_t msg)
1546 struct socket *so = msg->base.nm_so;
1547 struct mbuf *m = msg->send.nm_m;
1548 struct mbuf *controlp = msg->send.nm_control;
1549 int flags = msg->send.nm_flags;
1550 struct ipxpcb *ipxp;
1555 ipxp = sotoipxpcb(so);
1556 cb = ipxtospxpcb(ipxp);
1559 if (flags & PRUS_OOB) {
1560 if (ssb_space(&so->so_snd) < -512) {
1564 cb->s_oobflags |= SF_SOOB;
1566 if (controlp != NULL) {
1567 u_short *p = mtod(controlp, u_short *);
1569 if ((p[0] == 5) && (p[1] == 1)) { /* XXXX, for testing */
1570 cb->s_shdr.spx_dt = *(u_char *)(&p[2]);
1576 error = spx_output(cb, m);
1579 if (controlp != NULL)
1584 lwkt_replymsg(&msg->lmsg, error);
1588 spx_shutdown(netmsg_t msg)
1590 struct socket *so = msg->base.nm_so;
1591 struct ipxpcb *ipxp;
1596 ipxp = sotoipxpcb(so);
1597 cb = ipxtospxpcb(ipxp);
1601 cb = spx_usrclosed(cb);
1603 error = spx_output(cb, NULL);
1605 lwkt_replymsg(&msg->lmsg, error);
1609 spx_sp_attach(netmsg_t msg)
1611 struct socket *so = msg->base.nm_so;
1612 struct ipxpcb *ipxp;
1615 error = spx_attach_oncpu(so, msg->attach.nm_proto, msg->attach.nm_ai);
1617 ipxp = sotoipxpcb(so);
1618 ((struct spxpcb *)ipxp->ipxp_pcb)->s_flags |=
1619 (SF_HI | SF_HO | SF_PI);
1621 lwkt_replymsg(&msg->lmsg, error);
1625 * Create template to be used to send spx packets on a connection.
1626 * Called after host entry created, fills
1627 * in a skeletal spx header (choosing connection id),
1628 * minimizing the amount of work necessary when the connection is used.
1631 spx_template(struct spxpcb *cb)
1633 struct ipxpcb *ipxp = cb->s_ipxpcb;
1634 struct ipx *ipx = cb->s_ipx;
1635 struct signalsockbuf *ssb = &(ipxp->ipxp_socket->so_snd);
1637 ipx->ipx_pt = IPXPROTO_SPX;
1638 ipx->ipx_sna = ipxp->ipxp_laddr;
1639 ipx->ipx_dna = ipxp->ipxp_faddr;
1640 cb->s_sid = htons(spx_iss);
1641 spx_iss += SPX_ISSINCR/2;
1643 cb->s_cwnd = (ssb_space(ssb) * CUNIT) / cb->s_mtu;
1644 cb->s_ssthresh = cb->s_cwnd; /* Try to expand fast to full complement
1646 cb->s_cwmx = (ssb_space(ssb) * CUNIT) / (2 * sizeof(struct spx));
1647 cb->s_cwmx = max(cb->s_cwmx, cb->s_cwnd);
1648 /* But allow for lots of little packets as well */
1652 * Close a SPIP control block:
1653 * discard spx control block itself
1654 * discard ipx protocol control block
1655 * wake up any sleepers
1657 static struct spxpcb *
1658 spx_close(struct spxpcb *cb)
1661 struct ipxpcb *ipxp = cb->s_ipxpcb;
1662 struct socket *so = ipxp->ipxp_socket;
1664 while (!LIST_EMPTY(&cb->s_q)) {
1665 q = LIST_FIRST(&cb->s_q);
1666 LIST_REMOVE(q, sq_entry);
1667 m_freem(q->si_mbuf);
1670 m_free(cb->s_ipx_m);
1673 soisdisconnected(so);
1674 ipx_pcbdetach(ipxp);
1675 spxstat.spxs_closed++;
1680 * Someday we may do level 3 handshaking
1681 * to close a connection or send a xerox style error.
1682 * For now, just close.
1684 static struct spxpcb *
1685 spx_usrclosed(struct spxpcb *cb)
1687 return (spx_close(cb));
1690 static struct spxpcb *
1691 spx_disconnect(struct spxpcb *cb)
1693 return (spx_close(cb));
1697 * Drop connection, reporting
1698 * the specified error.
1700 static struct spxpcb *
1701 spx_drop(struct spxpcb *cb, int errno)
1703 struct socket *so = cb->s_ipxpcb->ipxp_socket;
1706 * someday, in the xerox world
1707 * we will generate error protocol packets
1708 * announcing that the socket has gone away.
1710 if (TCPS_HAVERCVDSYN(cb->s_state)) {
1711 spxstat.spxs_drops++;
1712 cb->s_state = TCPS_CLOSED;
1715 spxstat.spxs_conndrops++;
1716 so->so_error = errno;
1717 return (spx_close(cb));
1721 * Fast timeout routine for processing delayed acks
1726 struct ipxpcb *ipxp;
1730 LIST_FOREACH(ipxp, &ipxpcb_list, ipxp_list) {
1731 if ((cb = (struct spxpcb *)ipxp->ipxp_pcb) != NULL &&
1732 (cb->s_flags & SF_DELACK)) {
1733 cb->s_flags &= ~SF_DELACK;
1734 cb->s_flags |= SF_ACKNOW;
1735 spxstat.spxs_delack++;
1736 spx_output(cb, NULL);
1743 * spx protocol timeout routine called every 500 ms.
1744 * Updates the timers in all active pcb's and
1745 * causes finite state machine actions if timers expire.
1750 struct ipxpcb *ip, *ip_temp;
1755 * Search through tcb's and update active timers.
1758 LIST_FOREACH_MUTABLE(ip, &ipxpcb_list, ipxp_list, ip_temp) {
1759 cb = ipxtospxpcb(ip);
1762 for (i = 0; i < SPXT_NTIMERS; i++) {
1763 if (cb->s_timer[i] && --cb->s_timer[i] == 0) {
1764 if (spx_timers(cb, i) == NULL)
1772 spx_iss += SPX_ISSINCR/PR_SLOWHZ; /* increment iss */
1777 * SPX timer processing.
1779 static struct spxpcb *
1780 spx_timers(struct spxpcb *cb, int timer)
1785 cb->s_force = 1 + timer;
1789 * 2 MSL timeout in shutdown went off. TCP deletes connection
1793 kprintf("spx: SPXT_2MSL went off for no reason\n");
1794 cb->s_timer[timer] = 0;
1798 * Retransmission timer went off. Message has not
1799 * been acked within retransmit interval. Back off
1800 * to a longer retransmit interval and retransmit one packet.
1803 if (++cb->s_rxtshift > SPX_MAXRXTSHIFT) {
1804 cb->s_rxtshift = SPX_MAXRXTSHIFT;
1805 spxstat.spxs_timeoutdrop++;
1806 cb = spx_drop(cb, ETIMEDOUT);
1809 spxstat.spxs_rexmttimeo++;
1810 rexmt = ((cb->s_srtt >> 2) + cb->s_rttvar) >> 1;
1811 rexmt *= spx_backoff[cb->s_rxtshift];
1812 SPXT_RANGESET(cb->s_rxtcur, rexmt, SPXTV_MIN, SPXTV_REXMTMAX);
1813 cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
1815 * If we have backed off fairly far, our srtt
1816 * estimate is probably bogus. Clobber it
1817 * so we'll take the next rtt measurement as our srtt;
1818 * move the current srtt into rttvar to keep the current
1819 * retransmit times until then.
1821 if (cb->s_rxtshift > SPX_MAXRXTSHIFT / 4 ) {
1822 cb->s_rttvar += (cb->s_srtt >> 2);
1825 cb->s_snxt = cb->s_rack;
1827 * If timing a packet, stop the timer.
1831 * See very long discussion in tcp_timer.c about congestion
1832 * window and sstrhesh
1834 win = min(cb->s_swnd, (cb->s_cwnd/CUNIT)) / 2;
1838 cb->s_ssthresh = win * CUNIT;
1839 spx_output(cb, NULL);
1843 * Persistance timer into zero window.
1844 * Force a probe to be sent.
1847 spxstat.spxs_persisttimeo++;
1849 spx_output(cb, NULL);
1853 * Keep-alive timer went off; send something
1854 * or drop connection if idle for too long.
1857 spxstat.spxs_keeptimeo++;
1858 if (cb->s_state < TCPS_ESTABLISHED)
1860 if (cb->s_ipxpcb->ipxp_socket->so_options & SO_KEEPALIVE) {
1861 if (cb->s_idle >= SPXTV_MAXIDLE)
1863 spxstat.spxs_keepprobe++;
1864 spx_output(cb, NULL);
1867 cb->s_timer[SPXT_KEEP] = SPXTV_KEEP;
1870 spxstat.spxs_keepdrops++;
1871 cb = spx_drop(cb, ETIMEDOUT);