xref: /csrg-svn/sys/netns/spp_usrreq.c (revision 24047)
1 /*
2  * Copyright (c) 1982 Regents of the University of California.
3  * All rights reserved.  The Berkeley software License Agreement
4  * specifies the terms and conditions for redistribution.
5  *
6  *	@(#)spp_usrreq.c	6.6 (Berkeley) 07/26/85
7  */
8 
9 #include "param.h"
10 #include "dir.h"
11 #include "user.h"
12 #include "mbuf.h"
13 #include "protosw.h"
14 #include "socket.h"
15 #include "socketvar.h"
16 #include "errno.h"
17 
18 #include "../net/if.h"
19 #include "../net/route.h"
20 #include "../netinet/tcp_fsm.h"
21 #include "../netinet/tcp_timer.h"
22 
23 #include "ns.h"
24 #include "ns_pcb.h"
25 #include "idp.h"
26 #include "idp_var.h"
27 #include "ns_error.h"
28 #include "sp.h"
29 #include "spidp.h"
30 #include "spp_var.h"
31 #include "spp_debug.h"
32 
33 /*
34  * SP protocol implementation.
35  */
36 spp_init()
37 {
38 
39 	spp_iss = 1; /* WRONG !! should fish it out of TODR */
40 }
41 struct spidp spp_savesi;
42 int traceallspps = 0;
43 extern int sppconsdebug;
44 
45 int spp_hardnosed;
46 spp_input(m, nsp)
47 	register struct mbuf *m;
48 	register struct nspcb *nsp;
49 {
50 	register struct sppcb *cb;
51 	register struct spidp *si = mtod(m, struct spidp *);
52 	register struct socket *so;
53 	int len; short ostate;
54 	int dropsocket = 0;
55 
56 
57 	if (nsp==0) {
58 		panic("No nspcb in spp_input\n");
59 		return;
60 	}
61 
62 	cb = nstosppcb(nsp);
63 	if (cb == 0) goto bad;
64 
65 	if (m->m_len < sizeof(*si)) {
66 		if ((m = m_pullup(m, sizeof(*si)))==0) {
67 			spp_istat.hdrops++;
68 			return;
69 		}
70 		si = mtod(m, struct spidp *);
71 	}
72 	si->si_seq = ntohs(si->si_seq);
73 	si->si_ack = ntohs(si->si_ack);
74 	si->si_alo = ntohs(si->si_alo);
75 
76 	so = nsp->nsp_socket;
77 	if (so->so_options & SO_DEBUG || traceallspps) {
78 		ostate = cb->s_state;
79 		spp_savesi = *si;
80 	}
81 	if (so->so_options & SO_ACCEPTCONN) {
82 		so = sonewconn(so);
83 		if (so == 0) {
84 			spp_istat.nonucn++;
85 			goto drop;
86 		}
87 		/*
88 		 * This is ugly, but ....
89 		 *
90 		 * Mark socket as temporary until we're
91 		 * committed to keeping it.  The code at
92 		 * ``drop'' and ``dropwithreset'' check the
93 		 * flag dropsocket to see if the temporary
94 		 * socket created here should be discarded.
95 		 * We mark the socket as discardable until
96 		 * we're committed to it below in TCPS_LISTEN.
97 		 */
98 		dropsocket++;
99 		nsp = (struct nspcb *)so->so_pcb;
100 		nsp->nsp_laddr = si->si_dna;
101 		cb = nstosppcb(nsp);
102 		cb->s_state = TCPS_LISTEN;
103 	}
104 
105 	/*
106 	 * Packet received on connection.
107 	 * reset idle time and keep-alive timer;
108 	 */
109 	cb->s_idle = 0;
110 	cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
111 
112 	switch (cb->s_state) {
113 
114 	case TCPS_LISTEN:{
115 		struct mbuf *am;
116 		register struct sockaddr_ns *sns;
117 		struct ns_addr laddr;
118 
119 		/*
120 		 * If somebody here was carying on a conversation
121 		 * and went away, and his pen pal thinks he can
122 		 * still talk, we get the misdirected packet.
123 		 */
124 		if (spp_hardnosed && (si->si_did != 0 || si->si_seq != 0)) {
125 			spp_istat.gonawy++;
126 			goto dropwithreset;
127 		}
128 		am = m_get(M_DONTWAIT, MT_SONAME);
129 		if (am == NULL)
130 			goto drop;
131 		am->m_len = sizeof (struct sockaddr_ns);
132 		sns = mtod(am, struct sockaddr_ns *);
133 		sns->sns_family = AF_NS;
134 		sns->sns_addr = si->si_sna;
135 		laddr = nsp->nsp_laddr;
136 		if (ns_nullhost(laddr))
137 			nsp->nsp_laddr = si->si_dna;
138 		if (ns_pcbconnect(nsp, am)) {
139 			nsp->nsp_laddr = laddr;
140 			(void) m_free(am);
141 			spp_istat.noconn++;
142 			goto drop;
143 		}
144 		(void) m_free(am);
145 		cb->s_state = TCPS_SYN_RECEIVED;
146 		spp_template(cb);
147 		cb->s_did = si->si_sid;
148 		cb->s_rack = si->si_ack;
149 		cb->s_ralo = si->si_alo;
150 		cb->s_flags |= SF_AK;
151 		cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
152 		dropsocket = 0;		/* committed to socket */
153 		}
154 		break;
155 
156 	/*
157 	 * This state means that we have gotten a response
158 	 * to our attempt to establish a connection.
159 	 * We fill in the data from the other side,
160 	 * telling us which port to respond to, instead of the well-
161 	 * known one we might have sent to in the first place.
162 	 * We also require that this is a response to our
163 	 * connection id.
164 	 */
165 	case TCPS_SYN_SENT:
166 		if (si->si_did!=cb->s_sid) {
167 			spp_istat.notme++;
168 			goto drop;
169 		}
170 		cb->s_did = si->si_sid;
171 		cb->s_rack = si->si_ack;
172 		cb->s_ralo = si->si_alo;
173 		cb->s_dport = nsp->nsp_fport =  si->si_sport;
174 		cb->s_timer[TCPT_REXMT] = 0;
175 		cb->s_flags |= SF_AK;
176 		soisconnected(so);
177 		cb->s_state = TCPS_ESTABLISHED;
178 		break;
179 	/*
180 	 * This state means that we have heard a response
181 	 * to our acceptance of their connection
182 	 * It is probably logically unnecessary in this
183 	 * implementation.
184 	 */
185 	 case TCPS_SYN_RECEIVED:
186 		if (si->si_did!=cb->s_sid) {
187 			spp_istat.wrncon++;
188 			goto drop;
189 		}
190 		nsp->nsp_fport =  si->si_sport;
191 		cb->s_timer[TCPT_REXMT] = 0;
192 		cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
193 		soisconnected(so);
194 		cb->s_state = TCPS_ESTABLISHED;
195 	}
196 	if (so->so_options & SO_DEBUG || traceallspps)
197 		spp_trace(SA_INPUT, ostate, cb, &spp_savesi, 0);
198 
199 	m->m_len -= sizeof (struct idp);
200 	m->m_off += sizeof (struct idp);
201 
202 	if (spp_reass(cb,si)) {
203 		goto drop;
204 	}
205 	spp_output(cb,(struct mbuf *)0);
206 	return;
207 
208 dropwithreset:
209 	if (dropsocket)
210 		(void) soabort(so);
211 	si->si_seq = ntohs(si->si_seq);
212 	si->si_ack = ntohs(si->si_ack);
213 	si->si_alo = ntohs(si->si_alo);
214 	ns_error(dtom(si), NS_ERR_NOSOCK, 0);
215 	if (cb->s_nspcb->nsp_socket->so_options & SO_DEBUG || traceallspps)
216 		spp_trace(SA_DROP, ostate, cb, &spp_savesi, 0);
217 	return;
218 
219 drop:
220 bad:
221 	if (cb==0 || cb->s_nspcb->nsp_socket->so_options & SO_DEBUG || traceallspps)
222 		spp_trace(SA_DROP, ostate, cb, &spp_savesi, 0);
223 	m_freem(m);
224 }
225 
226 /*
227  * This is structurally similar to the tcp reassembly routine
228  * but its function is somewhat different:  It merely queues
229  * packets up, and suppresses duplicates.
230  */
231 spp_reass(cb,si)
232 register struct sppcb *cb;
233 register struct spidp *si;
234 {
235 	register struct spidp_q *q;
236 	register struct mbuf *m;
237 	struct socket *so = cb->s_nspcb->nsp_socket;
238 	struct sockbuf *sb = & (so->so_rcv);
239 	char packetp = cb->s_flags & SF_HI;
240 	char wakeup = 0;
241 
242 
243 	if (si==SI(0))
244 		goto present;
245 	/*
246 	 * Update our news from them.
247 	 */
248 	if (si->si_cc & SP_SA)
249 		cb->s_flags |= SF_DELACK;
250 	if (SSEQ_GT(si->si_ack,cb->s_rack)) {
251 		cb->s_rack = si->si_ack;
252 		cb->s_timer[TCPT_REXMT] = 0;
253 
254 		/*
255 		 * If transmit timer is running and timed sequence
256 		 * number was acked, update smoothed round trip time.
257 		 */
258 		if (cb->s_rtt && SSEQ_GT(si->si_ack, cb->s_rtseq)) {
259 			if (cb->s_srtt == 0)
260 				cb->s_srtt = cb->s_rtt;
261 			else
262 				cb->s_srtt =
263 				    tcp_alpha * cb->s_srtt +
264 				    (1 - tcp_alpha) * cb->s_rtt;
265 			cb->s_rtt = 0;
266 		}
267 	}
268 	if (SSEQ_GT(si->si_alo,cb->s_ralo)) {
269 		cb->s_ralo = si->si_alo;
270 		cb->s_timer[TCPT_PERSIST] = 0;
271 	}
272 	/*
273 	 * If this is a system packet, we don't need to
274 	 * queue it up, and won't update acknowledge #
275 	 */
276 	if (si->si_cc & SP_SP) {
277 		m_freem(dtom(si));
278 		return (0);
279 	}
280 
281 	/*
282 	 * If this packet number has a sequence number less
283 	 * than that of the first packet not yet seen coming
284 	 * from them, this must be a duplicate, so drop.
285 	 */
286 	if (SSEQ_LT(si->si_seq,cb->s_ack)) {
287 		spp_istat.bdreas++;
288 		if (si->si_seq==cb->s_ack-1)
289 			spp_istat.lstdup++;
290 		return (1);
291 	}
292 	/*
293 	 * If this packet number is higher than that which
294 	 * we have allocated refuse it, unless urgent
295 	 */
296 	if (SSEQ_GT(si->si_seq,cb->s_alo) && (!(si->si_cc & SP_OB))) {
297 		spp_istat.notyet++;
298 		return (1);
299 	}
300 	/*
301 	 * If this packet is urgent, inform process
302 	 */
303 	if (si->si_cc & SP_OB) {
304 		cb->s_iobc = ((char *)si)[1 + sizeof(*si)];
305 		sohasoutofband(so);
306 	}
307 
308 	/*
309 	 * Loop through all packets queued up to insert in
310 	 * appropriate sequence.
311 	 */
312 
313 	for (q = cb->s_q.si_next; q!=&cb->s_q; q = q->si_next) {
314 	    if (si->si_seq==SI(q)->si_seq) return (1); /*duplicate */
315 	    if (SSEQ_LT(si->si_seq,SI(q)->si_seq)) break;
316 	}
317 	insque(si,q->si_prev);
318 
319 present:
320 #define SPINC sizeof(struct sphdr)
321 	/*
322 	 * Loop through all packets queued up to update acknowledge
323 	 * number, and present all acknowledged data to user;
324 	 * If in packet interface mode, show packet headers.
325 	 */
326 	for (q = cb->s_q.si_next; q!=&cb->s_q; q = q->si_next) {
327 		  if (SI(q)->si_seq==cb->s_ack) {
328 			cb->s_ack++;
329 			m = dtom(q);
330 			if (SI(q)->si_cc & SP_OB) {
331 				if (sb->sb_cc)
332 					so->so_oobmark = sb->sb_cc;
333 				else
334 					so->so_state |= SS_RCVATMARK;
335 			}
336 			q = q->si_prev;
337 			remque(q->si_next);
338 			wakeup = 1;
339 			if (packetp) {
340 				sbappendrecord(sb,m);
341 			} else {
342 				cb->s_rhdr = *mtod(m, struct sphdr *);
343 				m->m_off += SPINC;
344 				m->m_len -= SPINC;
345 				sbappend(sb,m);
346 			}
347 		  } else
348 			break;
349 	}
350 	if (wakeup) sorwakeup(so);
351 	return (0);
352 }
353 
354 spp_ctlinput(cmd, arg)
355 	int cmd;
356 	caddr_t arg;
357 {
358 	struct ns_addr *na;
359 	extern u_char nsctlerrmap[];
360 	extern spp_abort();
361 	struct ns_errp *errp;
362 	struct nspcb *nsp;
363 	int type;
364 
365 	if (cmd < 0 || cmd > PRC_NCMDS)
366 		return;
367 	type = NS_ERR_UNREACH_HOST;
368 
369 	switch (cmd) {
370 
371 	case PRC_ROUTEDEAD:
372 	case PRC_QUENCH:
373 		break;
374 
375 	case PRC_IFDOWN:
376 		na = &((struct sockaddr_ns *)arg)->sns_addr;
377 		break;
378 
379 	case PRC_HOSTDEAD:
380 	case PRC_HOSTUNREACH:
381 		na = (struct ns_addr *)arg;
382 		break;
383 
384 	default:
385 		errp = (struct ns_errp *)arg;
386 		na = &errp->ns_err_idp.idp_dna;
387 		type = errp->ns_err_num;
388 		type = ntohs(type);
389 	}
390 	switch (type) {
391 
392 	case NS_ERR_UNREACH_HOST:
393 		ns_pcbnotify(na, (int)nsctlerrmap[cmd], spp_abort, (long) 0);
394 		break;
395 
396 	case NS_ERR_TOO_BIG:
397 	case NS_ERR_NOSOCK:
398 		nsp = ns_pcblookup(na, errp->ns_err_idp.idp_sna.x_port,
399 			NS_WILDCARD);
400 		if (nsp) {
401 			if(nsp->nsp_pcb)
402 				spp_drop(nsp->nsp_pcb, (int)nsctlerrmap[cmd]);
403 			else
404 				idp_drop(nsp, (int)nsctlerrmap[cmd]);
405 		}
406 	}
407 }
408 
409 int
410 spp_fixmtu(nsp)
411 register struct nspcb *nsp;
412 {
413 	register struct sppcb *cb = (struct sppcb *)(nsp->nsp_pcb);
414 	register struct mbuf *m;
415 	register struct spidp *si;
416 	struct ns_errp *ep;
417 	struct sockbuf *sb;
418 	int badseq, len;
419 	struct mbuf *firstbad, *m0;
420 
421 	if (cb) {
422 		/*
423 		 * The notification that we have sent
424 		 * too much is bad news -- we will
425 		 * have to go through queued up so far
426 		 * splitting ones which are too big and
427 		 * reassigning sequence numbers and checksums.
428 		 * we should then retransmit all packets from
429 		 * one above the offending packet to the last one
430 		 * we had sent (or our allocation)
431 		 * then the offending one so that the any queued
432 		 * data at our destination will be discarded.
433 		 */
434 		 ep = (struct ns_errp *)nsp->nsp_notify_param;
435 		 sb = &nsp->nsp_socket->so_snd;
436 		 cb->s_mtu = ep->ns_err_param;
437 		 badseq = SI(&ep->ns_err_idp)->si_seq;
438 		 for (m = sb->sb_mb; m; m = m->m_act) {
439 			si = mtod(m, struct spidp *);
440 			if (si->si_seq == badseq)
441 				break;
442 		 }
443 		 if (m==0) return;
444 		 firstbad = m;
445 		 /*for (;;) {*/
446 			/* calculate length */
447 			for (m0 = m, len = 0; m ; m = m->m_next)
448 				len += m->m_len;
449 			if (len > cb->s_mtu) {
450 			}
451 		/* FINISH THIS
452 		} */
453 	}
454 }
455 
456 int spp_output_cnt = 0;
457 
458 spp_output(cb, m0)
459 	register struct sppcb *cb;
460 	struct mbuf *m0;
461 {
462 	struct socket *so = cb->s_nspcb->nsp_socket;
463 	register struct mbuf *m;
464 	register struct spidp *si = (struct spidp *) 0;
465 	register struct sockbuf *sb = &(so->so_snd);
466 	register int len = 0;
467 	int flags, debit, mtu = cb->s_mtu;
468 	int error = 0; u_short lookfor = 0;
469 	struct mbuf *mprev;
470 	extern int idpcksum;
471 
472 	if (m0)
473 	{
474 		for (m = m0; m ; m = m->m_next) {
475 			mprev = m;
476 			len += m->m_len;
477 		}
478 		if (len > mtu) {
479 			if (cb->s_flags & SF_PI) {
480 				m_freem(m0);
481 				return (EMSGSIZE);
482 			} else {
483 				int off = 0;
484 				while (len > mtu) {
485 					m = m_copy(m0, off, mtu);
486 					if (m==NULL) {
487 						m_freem(m0);
488 						return (ENOBUFS);
489 					}
490 					error = spp_output(cb, m);
491 					if (error) {
492 						m_freem(m0);
493 						return (error);
494 					}
495 					m_adj(m0, mtu);
496 					len -= mtu;
497 				}
498 			}
499 		}
500 		if (len & 1) {
501 			m = mprev;
502 			if (m->m_len + m->m_off < MMAXOFF) {
503 				m->m_len++;
504 			} else {
505 				struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA);
506 
507 				if (m1 == 0) {
508 					m_freem(m0);
509 					return (ENOBUFS);
510 				}
511 				m1->m_len = 1;
512 				m1->m_off = MMAXOFF - 1;
513 				mprev->m_next = m1;
514 			}
515 		}
516 		m = m_get(M_DONTWAIT, MT_HEADER);
517 		if (m == 0) {
518 			m_freem(m0);
519 			return (ENOBUFS);
520 		}
521 
522 		/*
523 		 * Fill in mbuf with extended SP header
524 		 * and addresses and length put into network format.
525 		 */
526 		m->m_off = MMAXOFF - sizeof (struct spidp);
527 		m->m_len = sizeof (struct spidp);
528 		m->m_next = m0;
529 		si = mtod(m, struct spidp *);
530 		*si = cb->s_shdr;
531 		if ((cb->s_flags & SF_PI) && (cb->s_flags & SF_HO)) {
532 			register struct sphdr *sh = mtod(m0, struct sphdr *);
533 			si->si_dt = sh->sp_dt;
534 			si->si_cc |= sh->sp_cc & SP_EM;
535 			m0->m_len -= sizeof (*sh);
536 			m0->m_off += sizeof (*sh);
537 			len -= sizeof (*sh);
538 		}
539 		len += sizeof(*si);
540 		if (cb->s_oobflags & SF_SOOB) {
541 			/*
542 			 * Per jqj@cornell:
543 			 * make sure OB packets convey exactly 1 byte.
544 			 * If the packet is 1 byte or larger, we
545 			 * have already guaranted there to be at least
546 			 * one garbage byte for the checksum, and
547 			 * extra bytes shouldn't hurt!
548 			 *
549 			 */
550 			if (len > sizeof(*si)) {
551 				si->si_cc |= SP_OB;
552 				len = (1 + sizeof(*si));
553 			}
554 		}
555 		si->si_len = htons(len);
556 		/*
557 		 * queue stuff up for output
558 		 */
559 		sbappendrecord(sb,m);
560 		cb->s_seq++;
561 	}
562 output:
563 	/*
564 	 * update window
565 	 */
566 	{
567 		register struct sockbuf *sb = &so->so_rcv;
568 		int credit = ((sb->sb_mbmax - sb->sb_mbcnt) / cb->s_mtu);
569 		int alo = cb->s_ack + credit;
570 
571 		if (cb->s_alo < alo) cb->s_alo = alo;
572 	}
573 
574 	if (cb->s_oobflags & SF_SOOB) {
575 		/*
576 		 * must transmit this out of band packet
577 		 */
578 		cb->s_oobflags &= ~ SF_SOOB;
579 	} else {
580 		/*
581 		 * Decide what to transmit:
582 		 * If we have a new packet, send that
583 		 * (So long as it is in our allocation)
584 		 * If it is time to retransmit a packet,
585 		 * send that.
586 		 * Otherwise, see if it time to bang on them
587 		 * to ask for our current allocation.
588 		 */
589 		if (SSEQ_LT(cb->s_snt, cb->s_ralo))
590 			lookfor = cb->s_snt + 1;
591 		else if (cb->s_force==(1+TCPT_REXMT)) {
592 			lookfor = cb->s_rack;
593 		} else if (SSEQ_LT(cb->s_ralo, cb->s_seq)) {
594 			lookfor = 0;
595 			if (cb->s_timer[TCPT_PERSIST]==0) {
596 				spp_setpersist(cb);
597 			}
598 		}
599 		m = sb->sb_mb;
600 		while( m ) {
601 			si = mtod(m, struct spidp *);
602 			m = m->m_act;
603 			if (SSEQ_LT(si->si_seq, cb->s_rack)) {
604 				if ((sb->sb_flags & SB_WAIT)
605 				     || so->so_snd.sb_sel)
606 					 sowwakeup(so);
607 				sbdroprecord(sb);
608 				si = 0;
609 				continue;
610 			}
611 			if (SSEQ_LT(si->si_seq, lookfor))
612 				continue;
613 			break;
614 		}
615 		if (si && (si->si_seq != lookfor)) si = 0;
616 	}
617 	cb->s_want = lookfor;
618 
619 	if (si) {
620 		/*
621 		 * must make a copy of this packet for
622 		 * idp_output to monkey with
623 		 */
624 		 m = dtom(si);
625 		 m = m_copy(m, 0, M_COPYALL);
626 		 if (m==NULL)
627 			return (ENOBUFS);
628 		 m0 = m;
629 		 si = mtod(m, struct spidp *);
630 	} else if (cb->s_force || cb->s_flags & SF_AK) {
631 		/*
632 		 * Must send an acknowledgement or a probe
633 		 */
634 		m = m_get(M_DONTWAIT, MT_HEADER);
635 		if (m == 0)
636 			return (ENOBUFS);
637 		/*
638 		 * Fill in mbuf with extended SP header
639 		 * and addresses and length put into network format.
640 		 */
641 		m->m_off = MMAXOFF - sizeof (struct spidp);
642 		m->m_len = sizeof (*si);
643 		m->m_next = 0;
644 		si = mtod(m, struct spidp *);
645 		*si = cb->s_shdr;
646 		si->si_seq = cb->s_snt + 1;
647 		si->si_len = htons(sizeof (*si));
648 		si->si_cc |= SP_SP;
649 		cb->s_flags &= ~SF_AK;
650 	}
651 	/*
652 	 * Stuff checksum and output datagram.
653 	 */
654 	if (si) {
655 		/*
656 		 * If we are almost out of allocation
657 		 * or one of the timers has gone off
658 		 * request an ack.
659 		 */
660 		if (SSEQ_GEQ(cb->s_seq,cb->s_ralo))
661 			si->si_cc |= SP_SA;
662 		if (cb->s_force) {
663 			si->si_cc |= SP_SA;
664 			cb->s_force = 0;
665 		}
666 		/* If this is a new packet (and not a system packet),
667 		 * and we are not currently timing anything,
668 		 * time this one and ask for an ack.
669 		 */
670 		if (SSEQ_LT(cb->s_snt,si->si_seq) &&
671 		   (!(si->si_cc & SP_SP))) {
672 			cb->s_snt = si->si_seq;
673 			if (cb->s_rtt==0) {
674 				cb->s_rtseq = si->si_seq;
675 				cb->s_rtt = 1;
676 				si->si_cc |= SP_SA;
677 			}
678 			/*
679 			 * If the retransmit timer has not been set
680 			 * and this is a real packet
681 			 * then start the retransmit timer
682 			 */
683 			if (cb->s_timer[TCPT_REXMT]==0) {
684 				TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
685 					tcp_beta * cb->s_srtt, TCPTV_MIN,
686 					TCPTV_MAX);
687 				cb->s_rxtshift = 0;
688 			}
689 		}
690 		si->si_seq = htons(si->si_seq);
691 		si->si_alo = htons(cb->s_alo);
692 		si->si_ack = htons(cb->s_ack);
693 
694 		if (idpcksum) {
695 			si->si_sum = 0;
696 			len = ntohs(si->si_len);
697 			len = ((len - 1) | 1) + 1;
698 			si->si_sum = ns_cksum(dtom(si), len);
699 		} else
700 			si->si_sum = 0xffff;
701 
702 		if (so->so_options & SO_DEBUG || traceallspps)
703 			spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
704 		spp_output_cnt++;
705 		if (so->so_options & SO_DONTROUTE)
706 			error = ns_output(m, (struct route *)0, NS_ROUTETOIF);
707 		else
708 			error = ns_output(m, &cb->s_nspcb->nsp_route, 0);
709 		if (traceallspps && sppconsdebug) {
710 			printf("spp_out: %x\n", error);
711 		}
712 		return (error);
713 	}
714 	if (so->so_options & SO_DEBUG || traceallspps)
715 		spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
716 	return (error);
717 }
718 
719 /*ARGSUSED*/
720 spp_ctloutput(req, so, level, name, value)
721 	int req;
722 	struct socket *so;
723 	int name;
724 	struct mbuf **value;
725 {
726 	register struct mbuf *m;
727 	struct nspcb *nsp = sotonspcb(so);
728 	register struct sppcb *cb;
729 	int mask, error = 0;
730 
731 	if (level != NSPROTO_SPP) {
732 		/* This will have to be changed when we do more general
733 		   stacking of protocols */
734 		return (idp_ctloutput(req, so, level, name, value));
735 	}
736 	if (nsp == NULL) {
737 		error = EINVAL;
738 		goto release;
739 	} else
740 		cb = nstosppcb(nsp);
741 
742 	switch (req) {
743 
744 	case PRCO_GETOPT:
745 		if (value==NULL)
746 			return (EINVAL);
747 		m = m_get(M_DONTWAIT, MT_DATA);
748 		if (m==NULL)
749 			return (ENOBUFS);
750 		switch (name) {
751 
752 		case SO_HEADERS_ON_INPUT:
753 			mask = SF_HI;
754 			goto get_flags;
755 
756 		case SO_HEADERS_ON_OUTPUT:
757 			mask = SF_HO;
758 		get_flags:
759 			m->m_len = sizeof(short);
760 			m->m_off = MMAXOFF - sizeof(short);
761 			*mtod(m, short *) = cb->s_flags & mask;
762 			break;
763 
764 		case SO_LAST_HEADER:
765 			m->m_len = sizeof(struct sphdr);
766 			m->m_off = MMAXOFF - sizeof(struct sphdr);
767 			*mtod(m, struct sphdr *) = cb->s_rhdr;
768 			break;
769 
770 		case SO_DEFAULT_HEADERS:
771 			m->m_len = sizeof(struct spidp);
772 			m->m_off = MMAXOFF - sizeof(struct sphdr);
773 			*mtod(m, struct sphdr *) = cb->s_shdr.si_s;
774 		}
775 		*value = m;
776 		break;
777 
778 	case PRCO_SETOPT:
779 		switch (name) {
780 			int mask, *ok;
781 
782 		case SO_HEADERS_ON_INPUT:
783 			mask = SF_HI;
784 			goto set_head;
785 
786 		case SO_HEADERS_ON_OUTPUT:
787 			mask = SF_HO;
788 		set_head:
789 			if (value && *value) {
790 				ok = mtod(*value, int *);
791 				if (*ok)
792 					cb->s_flags |= mask;
793 				else
794 					cb->s_flags &= ~mask;
795 			} else error = EINVAL;
796 			break;
797 
798 		case SO_DEFAULT_HEADERS:
799 			{
800 				register struct sphdr *sp
801 						= mtod(*value, struct sphdr *);
802 				cb->s_dt = sp->sp_dt;
803 				cb->s_cc = sp->sp_cc & SP_EM;
804 			}
805 		}
806 		if (value && *value)
807 			m_freem(*value);
808 		break;
809 	}
810 	release:
811 		return (error);
812 }
813 
814 /*ARGSUSED*/
815 spp_usrreq(so, req, m, nam, rights)
816 	struct socket *so;
817 	int req;
818 	struct mbuf *m, *nam, *rights;
819 {
820 	struct nspcb *nsp = sotonspcb(so);
821 	register struct sppcb *cb;
822 	int s = splnet();
823 	int error = 0, ostate;
824 
825 	if (req == PRU_CONTROL)
826                 return (ns_control(so, (int)m, (caddr_t)nam,
827 			(struct ifnet *)rights));
828 	if (rights && rights->m_len) {
829 		error = EINVAL;
830 		goto release;
831 	}
832 	if (nsp == NULL) {
833 		if (req != PRU_ATTACH) {
834 			error = EINVAL;
835 			goto release;
836 		}
837 	} else
838 		cb = nstosppcb(nsp);
839 
840 	ostate = cb ? cb->s_state : 0;
841 
842 	switch (req) {
843 
844 	case PRU_ATTACH:
845 		if (nsp != NULL) {
846 			error = EISCONN;
847 			break;
848 		}
849 		error = ns_pcballoc(so, &nspcb);
850 		if (error)
851 			break;
852 		error = soreserve(so, 2048, 2048);
853 		if (error)
854 			break;
855 		nsp = sotonspcb(so);
856 		{
857 			struct mbuf *mm = m_getclr(M_DONTWAIT,MT_PCB);
858 
859 			if (mm==NULL) {
860 				error = ENOBUFS;
861 				break;
862 			}
863 			cb = mtod(mm, struct sppcb *);
864 			cb->s_state = TCPS_LISTEN;
865 			cb->s_snt = -1;
866 			cb->s_q.si_next = cb->s_q.si_prev = &cb->s_q;
867 			cb->s_nspcb = nsp;
868 			nsp->nsp_pcb = (caddr_t) cb;
869 		}
870 		break;
871 
872 	case PRU_DETACH:
873 		if (nsp == NULL) {
874 			error = ENOTCONN;
875 			break;
876 		}
877 		if (cb->s_state > TCPS_LISTEN)
878 			cb = spp_disconnect(cb);
879 		else
880 			cb = spp_close(cb);
881 		break;
882 
883 	case PRU_BIND:
884 		error = ns_pcbbind(nsp, nam);
885 		break;
886 
887 	case PRU_LISTEN:
888 		if (nsp->nsp_lport == 0)
889 			error = ns_pcbbind(nsp, (struct mbuf *)0);
890 		if (error == 0)
891 			cb->s_state = TCPS_LISTEN;
892 		break;
893 
894 	/*
895 	 * Initiate connection to peer.
896 	 * Enter SYN_SENT state, and mark socket as connecting.
897 	 * Start keep-alive timer, setup prototype header,
898 	 * Send initial system packet requesting connection.
899 	 */
900 	case PRU_CONNECT:
901 		if (nsp->nsp_lport == 0) {
902 			error = ns_pcbbind(nsp, (struct mbuf *)0);
903 			if (error)
904 				break;
905 		}
906 		error = ns_pcbconnect(nsp, nam);
907 		if (error)
908 			break;
909 		soisconnecting(so);
910 		cb->s_state = TCPS_SYN_SENT;
911 		cb->s_did = 0;
912 		spp_template(cb);
913 		cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
914 		cb->s_force = 1 + TCPTV_KEEP;
915 		/*
916 		 * Other party is required to respond to
917 		 * the port I send from, but he is not
918 		 * required to answer from where I am sending to,
919 		 * so allow wildcarding.
920 		 * original port I am sending to is still saved in
921 		 * cb->s_dport.
922 		 */
923 		nsp->nsp_fport = 0;
924 		error = spp_output(cb, (struct mbuf *) 0);
925 		break;
926 
927 	case PRU_CONNECT2:
928 		error = EOPNOTSUPP;
929 		break;
930 
931 	/*
932 	 * We may decide later to implement connection closing
933 	 * handshaking at the spp level optionally.
934 	 * here is the hook to do it:
935 	 */
936 	case PRU_DISCONNECT:
937 		cb = spp_disconnect(cb);
938 		break;
939 
940 	/*
941 	 * Accept a connection.  Essentially all the work is
942 	 * done at higher levels; just return the address
943 	 * of the peer, storing through addr.
944 	 */
945 	case PRU_ACCEPT: {
946 		struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *);
947 
948 		nam->m_len = sizeof (struct sockaddr_ns);
949 		sns->sns_family = AF_NS;
950 		sns->sns_addr = nsp->nsp_faddr;
951 		break;
952 		}
953 
954 	case PRU_SHUTDOWN:
955 		socantsendmore(so);
956 		cb = spp_usrclosed(cb);
957 		if (cb)
958 			error = spp_output(cb, (struct mbuf *) 0);
959 		break;
960 
961 	/*
962 	 * After a receive, possibly send acknowledgment
963 	 * updating allocation.
964 	 */
965 	case PRU_RCVD:
966 		(void) spp_output(cb, (struct mbuf *) 0);
967 		break;
968 
969 	case PRU_SEND:
970 		error = spp_output(cb, m);
971 		m = NULL;
972 		break;
973 
974 	case PRU_ABORT:
975 		spp_drop(cb, ECONNABORTED);
976 		break;
977 
978 	case PRU_SENSE:
979 	case PRU_CONTROL:
980 		m = NULL;
981 		error = EOPNOTSUPP;
982 		break;
983 
984 	case PRU_RCVOOB:
985 		if ( ! (cb->s_oobflags & SF_IOOB) ) {
986 			error = EWOULDBLOCK;
987 			break;
988 		}
989 		m->m_len = 1;
990 		*mtod(m, caddr_t) = cb->s_iobc;
991 		cb->s_oobflags &= ~ SF_IOOB;
992 		break;
993 
994 	case PRU_SENDOOB:
995 		if (sbspace(&so->so_snd) < -512) {
996 			m_freem(m);
997 			error = ENOBUFS;
998 			break;
999 		}
1000 		cb->s_oobflags |= SF_SOOB;
1001 		error = spp_output(cb, m);
1002 		m = NULL;
1003 		cb->s_oobflags &= ~SF_SOOB;
1004 		break;
1005 
1006 	case PRU_SOCKADDR:
1007 		ns_setsockaddr(nsp, nam);
1008 		break;
1009 
1010 	case PRU_PEERADDR:
1011 		ns_setpeeraddr(nsp, nam);
1012 		break;
1013 
1014 	case PRU_SLOWTIMO:
1015 		cb = spp_timers(cb, (int)nam);
1016 		break;
1017 
1018 	case PRU_FASTTIMO:
1019 	case PRU_PROTORCV:
1020 	case PRU_PROTOSEND:
1021 		error =  EOPNOTSUPP;
1022 		break;
1023 
1024 	default:
1025 		panic("sp_usrreq");
1026 	}
1027 	if (cb && (so->so_options & SO_DEBUG || traceallspps))
1028 		spp_trace(SA_USER, ostate, cb, (struct sphdr *)0, req);
1029 release:
1030 	if (m != NULL)
1031 		m_freem(m);
1032 	splx(s);
1033 	return (error);
1034 }
1035 
1036 spp_usrreq_sp(so, req, m, nam, rights)
1037 	struct socket *so;
1038 	int req;
1039 	struct mbuf *m, *nam, *rights;
1040 {
1041 	int error = spp_usrreq(so, req, m, nam, rights);
1042 
1043 	if (req==PRU_ATTACH && error==0) {
1044 		struct nspcb *nsp = sotonspcb(so);
1045 		((struct sppcb *)nsp->nsp_pcb)->s_flags |=
1046 					(SF_HI | SF_HO | SF_PI);
1047 	}
1048 	return (error);
1049 }
1050 
1051 /*
1052  * Create template to be used to send spp packets on a connection.
1053  * Called after host entry created, fills
1054  * in a skeletal spp header (choosing connection id),
1055  * minimizing the amount of work necessary when the connection is used.
1056  */
1057 spp_template(cb)
1058 	struct sppcb *cb;
1059 {
1060 	register struct nspcb *nsp = cb->s_nspcb;
1061 	register struct spidp *n = &(cb->s_shdr);
1062 
1063 	cb->s_mtu = 1024;
1064 	n->si_pt = NSPROTO_SPP;
1065 	n->si_sna = nsp->nsp_laddr;
1066 	n->si_dna = nsp->nsp_faddr;
1067 	n->si_sid = htons(spp_iss);
1068 	spp_iss += SPP_ISSINCR/2;
1069 	n->si_alo = 1;
1070 }
1071 
1072 /*
1073  * Close a SPIP control block:
1074  *	discard spp control block itself
1075  *	discard ns protocol control block
1076  *	wake up any sleepers
1077  */
1078 struct sppcb *
1079 spp_close(cb)
1080 	register struct sppcb *cb;
1081 {
1082 	register struct spidp_q *s;
1083 	struct nspcb *nsp = cb->s_nspcb;
1084 	struct socket *so = nsp->nsp_socket;
1085 	register struct mbuf *m;
1086 
1087 	s = cb->s_q.si_next;
1088 	while (s != &(cb->s_q)) {
1089 		s = s->si_next;
1090 		m = dtom(s->si_prev);
1091 		remque(s->si_prev);
1092 		m_freem(m);
1093 	}
1094 	(void) m_free(dtom(cb));
1095 	nsp->nsp_pcb = 0;
1096 	soisdisconnected(so);
1097 	ns_pcbdetach(nsp);
1098 	return ((struct sppcb *)0);
1099 }
1100 /*
1101  *	Someday we may do level 3 handshaking
1102  *	to close a connection or send a xerox style error.
1103  *	For now, just close.
1104  */
1105 struct sppcb *
1106 spp_usrclosed(cb)
1107 	register struct sppcb *cb;
1108 {
1109 	return (spp_close(cb));
1110 }
1111 struct sppcb *
1112 spp_disconnect(cb)
1113 	register struct sppcb *cb;
1114 {
1115 	return (spp_close(cb));
1116 }
1117 /*
1118  * Drop connection, reporting
1119  * the specified error.
1120  */
1121 struct sppcb *
1122 spp_drop(cb, errno)
1123 	register struct sppcb *cb;
1124 	int errno;
1125 {
1126 	struct socket *so = cb->s_nspcb->nsp_socket;
1127 
1128 	/*
1129 	 * someday, in the xerox world
1130 	 * we will generate error protocol packets
1131 	 * announcing that the socket has gone away.
1132 	 */
1133 	/*if (TCPS_HAVERCVDSYN(tp->t_state)) {
1134 		tp->t_state = TCPS_CLOSED;
1135 		(void) tcp_output(tp);
1136 	}*/
1137 	so->so_error = errno;
1138 	return (spp_close(cb));
1139 }
1140 
1141 spp_abort(nsp)
1142 	struct nspcb *nsp;
1143 {
1144 
1145 	spp_close((struct sppcb *)nsp->nsp_pcb);
1146 }
1147 
1148 spp_setpersist(cb)
1149 	register struct sppcb *cb;
1150 {
1151 
1152 	/*if (cb->s_timer[TCPT_REXMT])
1153 		panic("spp_output REXMT");*/
1154 	/*
1155 	 * Start/restart persistance timer.
1156 	 */
1157 	TCPT_RANGESET(cb->s_timer[TCPT_PERSIST],
1158 	    ((int)(tcp_beta * cb->s_srtt)) << cb->s_rxtshift,
1159 	    TCPTV_PERSMIN, TCPTV_MAX);
1160 	cb->s_rxtshift++;
1161 	if (cb->s_rxtshift >= TCP_MAXRXTSHIFT)
1162 		cb->s_rxtshift = 0;
1163 }
1164 /*
1165  * Fast timeout routine for processing delayed acks
1166  */
1167 int spp_ftcnt;
1168 spp_fasttimo()
1169 {
1170 	register struct nspcb *nsp;
1171 	register struct sppcb *cb;
1172 	int s = splnet();
1173 
1174 	nsp = nspcb.nsp_next;
1175 	spp_ftcnt++;
1176 	if (nsp)
1177 	for (; nsp != &nspcb; nsp = nsp->nsp_next)
1178 		if ((cb = (struct sppcb *)nsp->nsp_pcb) &&
1179 		    (cb->s_flags & SF_DELACK)) {
1180 			cb->s_flags &= ~SF_DELACK;
1181 			cb->s_flags |= SF_AK;
1182 			(void) spp_output(cb, (struct mbuf *) 0);
1183 		}
1184 	splx(s);
1185 }
1186 
1187 /*
1188  * spp protocol timeout routine called every 500 ms.
1189  * Updates the timers in all active pcb's and
1190  * causes finite state machine actions if timers expire.
1191  */
1192 spp_slowtimo()
1193 {
1194 	register struct nspcb *ip, *ipnxt;
1195 	register struct sppcb *cb;
1196 	int s = splnet();
1197 	register int i;
1198 
1199 	/*
1200 	 * Search through tcb's and update active timers.
1201 	 */
1202 	ip = nspcb.nsp_next;
1203 	if (ip == 0) {
1204 		splx(s);
1205 		return;
1206 	}
1207 	while (ip != &nspcb) {
1208 		cb = nstosppcb(ip);
1209 		ipnxt = ip->nsp_next;
1210 		if (cb == 0)
1211 			goto tpgone;
1212 		for (i = 0; i < TCPT_NTIMERS; i++) {
1213 			if (cb->s_timer[i] && --cb->s_timer[i] == 0) {
1214 				(void) spp_usrreq(cb->s_nspcb->nsp_socket,
1215 				    PRU_SLOWTIMO, (struct mbuf *)0,
1216 				    (struct mbuf *)i, (struct mbuf *)0);
1217 				if (ipnxt->nsp_prev != ip)
1218 					goto tpgone;
1219 			}
1220 		}
1221 		cb->s_idle++;
1222 		if (cb->s_rtt)
1223 			cb->s_rtt++;
1224 tpgone:
1225 		ip = ipnxt;
1226 	}
1227 	spp_iss += SPP_ISSINCR/PR_SLOWHZ;		/* increment iss */
1228 	splx(s);
1229 }
1230 
1231 float	spp_backoff[TCP_MAXRXTSHIFT] =
1232     { 1.0, 1.2, 1.4, 1.7, 2.0, 3.0, 5.0, 8.0, 16.0, 32.0 };
1233 extern int tcpexprexmtbackoff;
1234 /*
1235  * TCP timer processing.
1236  */
1237 struct sppcb *
1238 spp_timers(cb, timer)
1239 	register struct sppcb *cb;
1240 	int timer;
1241 {
1242 
1243 	cb->s_force = 1 + timer;
1244 	switch (timer) {
1245 
1246 	/*
1247 	 * 2 MSL timeout in shutdown went off.  Delete connection
1248 	 * control block.
1249 	 */
1250 	case TCPT_2MSL:
1251 		cb = spp_close(cb);
1252 		break;
1253 
1254 	/*
1255 	 * Retransmission timer went off.  Message has not
1256 	 * been acked within retransmit interval.  Back off
1257 	 * to a longer retransmit interval and retransmit all
1258 	 * unacknowledged messages in the window.
1259 	 */
1260 	case TCPT_REXMT:
1261 		cb->s_rxtshift++;
1262 		if (cb->s_rxtshift > TCP_MAXRXTSHIFT) {
1263 			cb = spp_drop(cb, ETIMEDOUT);
1264 			break;
1265 		}
1266 		(void) spp_output(cb, (struct mbuf *) 0);
1267 		TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
1268 		    (int)cb->s_srtt, TCPTV_MIN, TCPTV_MAX);
1269 		if (tcpexprexmtbackoff) {
1270 			TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
1271 			    cb->s_timer[TCPT_REXMT] << cb->s_rxtshift,
1272 			    TCPTV_MIN, TCPTV_MAX);
1273 		} else {
1274 			TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
1275 			    cb->s_timer[TCPT_REXMT] *
1276 			        spp_backoff[cb->s_rxtshift - 1],
1277 			    TCPTV_MIN, TCPTV_MAX);
1278 		}
1279 		break;
1280 
1281 	/*
1282 	 * Persistance timer into zero window.
1283 	 * Force a probe to be sent.
1284 	 */
1285 	case TCPT_PERSIST:
1286 		(void) spp_output(cb, (struct mbuf *) 0);
1287 		spp_setpersist(cb);
1288 		break;
1289 
1290 	/*
1291 	 * Keep-alive timer went off; send something
1292 	 * or drop connection if idle for too long.
1293 	 */
1294 	case TCPT_KEEP:
1295 		if (cb->s_state < TCPS_ESTABLISHED)
1296 			goto dropit;
1297 		if (cb->s_nspcb->nsp_socket->so_options & SO_KEEPALIVE) {
1298 		    	if (cb->s_idle >= TCPTV_MAXIDLE)
1299 				goto dropit;
1300 			(void) spp_output(cb, (struct mbuf *) 0);
1301 		} else
1302 			cb->s_idle = 0;
1303 		cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
1304 		break;
1305 	dropit:
1306 		cb = spp_drop(cb, ETIMEDOUT);
1307 		break;
1308 	}
1309 	return (cb);
1310 }
1311