xref: /csrg-svn/sys/netns/spp_usrreq.c (revision 24225)
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	6.7 (Berkeley) 08/09/85
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 	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, (u_char)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 	(void) 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, (u_char)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, (u_char)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 	extern struct nspcb *idp_drop();
362 	struct ns_errp *errp;
363 	struct nspcb *nsp;
364 	int type;
365 
366 	if (cmd < 0 || cmd > PRC_NCMDS)
367 		return;
368 	type = NS_ERR_UNREACH_HOST;
369 
370 	switch (cmd) {
371 
372 	case PRC_ROUTEDEAD:
373 	case PRC_QUENCH:
374 		break;
375 
376 	case PRC_IFDOWN:
377 		na = &((struct sockaddr_ns *)arg)->sns_addr;
378 		break;
379 
380 	case PRC_HOSTDEAD:
381 	case PRC_HOSTUNREACH:
382 		na = (struct ns_addr *)arg;
383 		break;
384 
385 	default:
386 		errp = (struct ns_errp *)arg;
387 		na = &errp->ns_err_idp.idp_dna;
388 		type = errp->ns_err_num;
389 		type = ntohs((u_short)type);
390 	}
391 	switch (type) {
392 
393 	case NS_ERR_UNREACH_HOST:
394 		ns_pcbnotify(na, (int)nsctlerrmap[cmd], spp_abort, (long) 0);
395 		break;
396 
397 	case NS_ERR_TOO_BIG:
398 	case NS_ERR_NOSOCK:
399 		nsp = ns_pcblookup(na, errp->ns_err_idp.idp_sna.x_port,
400 			NS_WILDCARD);
401 		if (nsp) {
402 			if(nsp->nsp_pcb)
403 				(void) spp_drop((struct sppcb *)nsp->nsp_pcb,
404 						(int)nsctlerrmap[cmd]);
405 			else
406 				(void) idp_drop(nsp, (int)nsctlerrmap[cmd]);
407 		}
408 	}
409 }
410 
411 #ifdef notdef
412 int
413 spp_fixmtu(nsp)
414 register struct nspcb *nsp;
415 {
416 	register struct sppcb *cb = (struct sppcb *)(nsp->nsp_pcb);
417 	register struct mbuf *m;
418 	register struct spidp *si;
419 	struct ns_errp *ep;
420 	struct sockbuf *sb;
421 	int badseq, len;
422 	struct mbuf *firstbad, *m0;
423 
424 	if (cb) {
425 		/*
426 		 * The notification that we have sent
427 		 * too much is bad news -- we will
428 		 * have to go through queued up so far
429 		 * splitting ones which are too big and
430 		 * reassigning sequence numbers and checksums.
431 		 * we should then retransmit all packets from
432 		 * one above the offending packet to the last one
433 		 * we had sent (or our allocation)
434 		 * then the offending one so that the any queued
435 		 * data at our destination will be discarded.
436 		 */
437 		 ep = (struct ns_errp *)nsp->nsp_notify_param;
438 		 sb = &nsp->nsp_socket->so_snd;
439 		 cb->s_mtu = ep->ns_err_param;
440 		 badseq = SI(&ep->ns_err_idp)->si_seq;
441 		 for (m = sb->sb_mb; m; m = m->m_act) {
442 			si = mtod(m, struct spidp *);
443 			if (si->si_seq == badseq)
444 				break;
445 		 }
446 		 if (m==0) return;
447 		 firstbad = m;
448 		 /*for (;;) {*/
449 			/* calculate length */
450 			for (m0 = m, len = 0; m ; m = m->m_next)
451 				len += m->m_len;
452 			if (len > cb->s_mtu) {
453 			}
454 		/* FINISH THIS
455 		} */
456 	}
457 }
458 #endif
459 
460 int spp_output_cnt = 0;
461 
462 spp_output(cb, m0)
463 	register struct sppcb *cb;
464 	struct mbuf *m0;
465 {
466 	struct socket *so = cb->s_nspcb->nsp_socket;
467 	register struct mbuf *m;
468 	register struct spidp *si = (struct spidp *) 0;
469 	register struct sockbuf *sb = &(so->so_snd);
470 	register int len = 0;
471 	int mtu = cb->s_mtu;
472 	int error = 0; u_short lookfor = 0;
473 	struct mbuf *mprev;
474 	extern int idpcksum;
475 
476 	if (m0)
477 	{
478 		for (m = m0; m ; m = m->m_next) {
479 			mprev = m;
480 			len += m->m_len;
481 		}
482 		if (len > mtu) {
483 			if (cb->s_flags & SF_PI) {
484 				m_freem(m0);
485 				return (EMSGSIZE);
486 			} else {
487 				int off = 0;
488 				while (len > mtu) {
489 					m = m_copy(m0, off, mtu);
490 					if (m==NULL) {
491 						m_freem(m0);
492 						return (ENOBUFS);
493 					}
494 					error = spp_output(cb, m);
495 					if (error) {
496 						m_freem(m0);
497 						return (error);
498 					}
499 					m_adj(m0, mtu);
500 					len -= mtu;
501 				}
502 			}
503 		}
504 		if (len & 1) {
505 			m = mprev;
506 			if (m->m_len + m->m_off < MMAXOFF) {
507 				m->m_len++;
508 			} else {
509 				struct mbuf *m1 = m_get(M_DONTWAIT, MT_DATA);
510 
511 				if (m1 == 0) {
512 					m_freem(m0);
513 					return (ENOBUFS);
514 				}
515 				m1->m_len = 1;
516 				m1->m_off = MMAXOFF - 1;
517 				mprev->m_next = m1;
518 			}
519 		}
520 		m = m_get(M_DONTWAIT, MT_HEADER);
521 		if (m == 0) {
522 			m_freem(m0);
523 			return (ENOBUFS);
524 		}
525 
526 		/*
527 		 * Fill in mbuf with extended SP header
528 		 * and addresses and length put into network format.
529 		 */
530 		m->m_off = MMAXOFF - sizeof (struct spidp);
531 		m->m_len = sizeof (struct spidp);
532 		m->m_next = m0;
533 		si = mtod(m, struct spidp *);
534 		*si = cb->s_shdr;
535 		if ((cb->s_flags & SF_PI) && (cb->s_flags & SF_HO)) {
536 			register struct sphdr *sh = mtod(m0, struct sphdr *);
537 			si->si_dt = sh->sp_dt;
538 			si->si_cc |= sh->sp_cc & SP_EM;
539 			m0->m_len -= sizeof (*sh);
540 			m0->m_off += sizeof (*sh);
541 			len -= sizeof (*sh);
542 		}
543 		len += sizeof(*si);
544 		if (cb->s_oobflags & SF_SOOB) {
545 			/*
546 			 * Per jqj@cornell:
547 			 * make sure OB packets convey exactly 1 byte.
548 			 * If the packet is 1 byte or larger, we
549 			 * have already guaranted there to be at least
550 			 * one garbage byte for the checksum, and
551 			 * extra bytes shouldn't hurt!
552 			 *
553 			 */
554 			if (len > sizeof(*si)) {
555 				si->si_cc |= SP_OB;
556 				len = (1 + sizeof(*si));
557 			}
558 		}
559 		si->si_len = htons((u_short)len);
560 		/*
561 		 * queue stuff up for output
562 		 */
563 		sbappendrecord(sb,m);
564 		cb->s_seq++;
565 	}
566 	/*
567 	 * update window
568 	 */
569 	{
570 		register struct sockbuf *sb2 = &so->so_rcv;
571 		int credit = ((sb2->sb_mbmax - sb2->sb_mbcnt) / cb->s_mtu);
572 		int alo = cb->s_ack + credit;
573 
574 		if (cb->s_alo < alo) cb->s_alo = alo;
575 	}
576 
577 	if (cb->s_oobflags & SF_SOOB) {
578 		/*
579 		 * must transmit this out of band packet
580 		 */
581 		cb->s_oobflags &= ~ SF_SOOB;
582 	} else {
583 		/*
584 		 * Decide what to transmit:
585 		 * If we have a new packet, send that
586 		 * (So long as it is in our allocation)
587 		 * If it is time to retransmit a packet,
588 		 * send that.
589 		 * Otherwise, see if it time to bang on them
590 		 * to ask for our current allocation.
591 		 */
592 		if (SSEQ_LT(cb->s_snt, cb->s_ralo))
593 			lookfor = cb->s_snt + 1;
594 		else if (cb->s_force==(1+TCPT_REXMT)) {
595 			lookfor = cb->s_rack;
596 		} else if (SSEQ_LT(cb->s_ralo, cb->s_seq)) {
597 			lookfor = 0;
598 			if (cb->s_timer[TCPT_PERSIST]==0) {
599 				spp_setpersist(cb);
600 			}
601 		}
602 		m = sb->sb_mb;
603 		while( m ) {
604 			si = mtod(m, struct spidp *);
605 			m = m->m_act;
606 			if (SSEQ_LT(si->si_seq, cb->s_rack)) {
607 				if ((sb->sb_flags & SB_WAIT)
608 				     || so->so_snd.sb_sel)
609 					 sowwakeup(so);
610 				sbdroprecord(sb);
611 				si = 0;
612 				continue;
613 			}
614 			if (SSEQ_LT(si->si_seq, lookfor))
615 				continue;
616 			break;
617 		}
618 		if (si && (si->si_seq != lookfor)) si = 0;
619 	}
620 	cb->s_want = lookfor;
621 
622 	if (si) {
623 		/*
624 		 * must make a copy of this packet for
625 		 * idp_output to monkey with
626 		 */
627 		 m = dtom(si);
628 		 m = m_copy(m, 0, (int)M_COPYALL);
629 		 if (m==NULL)
630 			return (ENOBUFS);
631 		 m0 = m;
632 		 si = mtod(m, struct spidp *);
633 	} else if (cb->s_force || cb->s_flags & SF_AK) {
634 		/*
635 		 * Must send an acknowledgement or a probe
636 		 */
637 		m = m_get(M_DONTWAIT, MT_HEADER);
638 		if (m == 0)
639 			return (ENOBUFS);
640 		/*
641 		 * Fill in mbuf with extended SP header
642 		 * and addresses and length put into network format.
643 		 */
644 		m->m_off = MMAXOFF - sizeof (struct spidp);
645 		m->m_len = sizeof (*si);
646 		m->m_next = 0;
647 		si = mtod(m, struct spidp *);
648 		*si = cb->s_shdr;
649 		si->si_seq = cb->s_snt + 1;
650 		si->si_len = htons(sizeof (*si));
651 		si->si_cc |= SP_SP;
652 		cb->s_flags &= ~SF_AK;
653 	}
654 	/*
655 	 * Stuff checksum and output datagram.
656 	 */
657 	if (si) {
658 		/*
659 		 * If we are almost out of allocation
660 		 * or one of the timers has gone off
661 		 * request an ack.
662 		 */
663 		if (SSEQ_GEQ(cb->s_seq,cb->s_ralo))
664 			si->si_cc |= SP_SA;
665 		if (cb->s_force) {
666 			si->si_cc |= SP_SA;
667 			cb->s_force = 0;
668 		}
669 		/* If this is a new packet (and not a system packet),
670 		 * and we are not currently timing anything,
671 		 * time this one and ask for an ack.
672 		 */
673 		if (SSEQ_LT(cb->s_snt,si->si_seq) &&
674 		   (!(si->si_cc & SP_SP))) {
675 			cb->s_snt = si->si_seq;
676 			if (cb->s_rtt==0) {
677 				cb->s_rtseq = si->si_seq;
678 				cb->s_rtt = 1;
679 				si->si_cc |= SP_SA;
680 			}
681 			/*
682 			 * If the retransmit timer has not been set
683 			 * and this is a real packet
684 			 * then start the retransmit timer
685 			 */
686 			if (cb->s_timer[TCPT_REXMT]==0) {
687 				TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
688 					tcp_beta * cb->s_srtt, TCPTV_MIN,
689 					TCPTV_MAX);
690 				cb->s_rxtshift = 0;
691 			}
692 		}
693 		si->si_seq = htons(si->si_seq);
694 		si->si_alo = htons(cb->s_alo);
695 		si->si_ack = htons(cb->s_ack);
696 
697 		if (idpcksum) {
698 			si->si_sum = 0;
699 			len = ntohs(si->si_len);
700 			len = ((len - 1) | 1) + 1;
701 			si->si_sum = ns_cksum(dtom(si), len);
702 		} else
703 			si->si_sum = 0xffff;
704 
705 		if (so->so_options & SO_DEBUG || traceallspps)
706 			spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
707 		spp_output_cnt++;
708 		if (so->so_options & SO_DONTROUTE)
709 			error = ns_output(m, (struct route *)0, NS_ROUTETOIF);
710 		else
711 			error = ns_output(m, &cb->s_nspcb->nsp_route, 0);
712 		if (traceallspps && sppconsdebug) {
713 			printf("spp_out: %x\n", error);
714 		}
715 		return (error);
716 	}
717 	if (so->so_options & SO_DEBUG || traceallspps)
718 		spp_trace(SA_OUTPUT, cb->s_state, cb, si, 0);
719 	return (error);
720 }
721 
722 /*ARGSUSED*/
723 spp_ctloutput(req, so, level, name, value)
724 	int req;
725 	struct socket *so;
726 	int name;
727 	struct mbuf **value;
728 {
729 	register struct mbuf *m;
730 	struct nspcb *nsp = sotonspcb(so);
731 	register struct sppcb *cb;
732 	int mask, error = 0;
733 
734 	if (level != NSPROTO_SPP) {
735 		/* This will have to be changed when we do more general
736 		   stacking of protocols */
737 		return (idp_ctloutput(req, so, level, name, value));
738 	}
739 	if (nsp == NULL) {
740 		error = EINVAL;
741 		goto release;
742 	} else
743 		cb = nstosppcb(nsp);
744 
745 	switch (req) {
746 
747 	case PRCO_GETOPT:
748 		if (value==NULL)
749 			return (EINVAL);
750 		m = m_get(M_DONTWAIT, MT_DATA);
751 		if (m==NULL)
752 			return (ENOBUFS);
753 		switch (name) {
754 
755 		case SO_HEADERS_ON_INPUT:
756 			mask = SF_HI;
757 			goto get_flags;
758 
759 		case SO_HEADERS_ON_OUTPUT:
760 			mask = SF_HO;
761 		get_flags:
762 			m->m_len = sizeof(short);
763 			m->m_off = MMAXOFF - sizeof(short);
764 			*mtod(m, short *) = cb->s_flags & mask;
765 			break;
766 
767 		case SO_LAST_HEADER:
768 			m->m_len = sizeof(struct sphdr);
769 			m->m_off = MMAXOFF - sizeof(struct sphdr);
770 			*mtod(m, struct sphdr *) = cb->s_rhdr;
771 			break;
772 
773 		case SO_DEFAULT_HEADERS:
774 			m->m_len = sizeof(struct spidp);
775 			m->m_off = MMAXOFF - sizeof(struct sphdr);
776 			*mtod(m, struct sphdr *) = cb->s_shdr.si_s;
777 		}
778 		*value = m;
779 		break;
780 
781 	case PRCO_SETOPT:
782 		switch (name) {
783 			int *ok;
784 
785 		case SO_HEADERS_ON_INPUT:
786 			mask = SF_HI;
787 			goto set_head;
788 
789 		case SO_HEADERS_ON_OUTPUT:
790 			mask = SF_HO;
791 		set_head:
792 			if (value && *value) {
793 				ok = mtod(*value, int *);
794 				if (*ok)
795 					cb->s_flags |= mask;
796 				else
797 					cb->s_flags &= ~mask;
798 			} else error = EINVAL;
799 			break;
800 
801 		case SO_DEFAULT_HEADERS:
802 			{
803 				register struct sphdr *sp
804 						= mtod(*value, struct sphdr *);
805 				cb->s_dt = sp->sp_dt;
806 				cb->s_cc = sp->sp_cc & SP_EM;
807 			}
808 		}
809 		if (value && *value)
810 			m_freem(*value);
811 		break;
812 	}
813 	release:
814 		return (error);
815 }
816 
817 /*ARGSUSED*/
818 spp_usrreq(so, req, m, nam, rights)
819 	struct socket *so;
820 	int req;
821 	struct mbuf *m, *nam, *rights;
822 {
823 	struct nspcb *nsp = sotonspcb(so);
824 	register struct sppcb *cb;
825 	int s = splnet();
826 	int error = 0, ostate;
827 
828 	if (req == PRU_CONTROL)
829                 return (ns_control(so, (int)m, (caddr_t)nam,
830 			(struct ifnet *)rights));
831 	if (rights && rights->m_len) {
832 		error = EINVAL;
833 		goto release;
834 	}
835 	if (nsp == NULL) {
836 		if (req != PRU_ATTACH) {
837 			error = EINVAL;
838 			goto release;
839 		}
840 	} else
841 		cb = nstosppcb(nsp);
842 
843 	ostate = cb ? cb->s_state : 0;
844 
845 	switch (req) {
846 
847 	case PRU_ATTACH:
848 		if (nsp != NULL) {
849 			error = EISCONN;
850 			break;
851 		}
852 		error = ns_pcballoc(so, &nspcb);
853 		if (error)
854 			break;
855 		error = soreserve(so, 2048, 2048);
856 		if (error)
857 			break;
858 		nsp = sotonspcb(so);
859 		{
860 			struct mbuf *mm = m_getclr(M_DONTWAIT,MT_PCB);
861 
862 			if (mm==NULL) {
863 				error = ENOBUFS;
864 				break;
865 			}
866 			cb = mtod(mm, struct sppcb *);
867 			cb->s_state = TCPS_LISTEN;
868 			cb->s_snt = -1;
869 			cb->s_q.si_next = cb->s_q.si_prev = &cb->s_q;
870 			cb->s_nspcb = nsp;
871 			nsp->nsp_pcb = (caddr_t) cb;
872 		}
873 		break;
874 
875 	case PRU_DETACH:
876 		if (nsp == NULL) {
877 			error = ENOTCONN;
878 			break;
879 		}
880 		if (cb->s_state > TCPS_LISTEN)
881 			cb = spp_disconnect(cb);
882 		else
883 			cb = spp_close(cb);
884 		break;
885 
886 	case PRU_BIND:
887 		error = ns_pcbbind(nsp, nam);
888 		break;
889 
890 	case PRU_LISTEN:
891 		if (nsp->nsp_lport == 0)
892 			error = ns_pcbbind(nsp, (struct mbuf *)0);
893 		if (error == 0)
894 			cb->s_state = TCPS_LISTEN;
895 		break;
896 
897 	/*
898 	 * Initiate connection to peer.
899 	 * Enter SYN_SENT state, and mark socket as connecting.
900 	 * Start keep-alive timer, setup prototype header,
901 	 * Send initial system packet requesting connection.
902 	 */
903 	case PRU_CONNECT:
904 		if (nsp->nsp_lport == 0) {
905 			error = ns_pcbbind(nsp, (struct mbuf *)0);
906 			if (error)
907 				break;
908 		}
909 		error = ns_pcbconnect(nsp, nam);
910 		if (error)
911 			break;
912 		soisconnecting(so);
913 		cb->s_state = TCPS_SYN_SENT;
914 		cb->s_did = 0;
915 		spp_template(cb);
916 		cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
917 		cb->s_force = 1 + TCPTV_KEEP;
918 		/*
919 		 * Other party is required to respond to
920 		 * the port I send from, but he is not
921 		 * required to answer from where I am sending to,
922 		 * so allow wildcarding.
923 		 * original port I am sending to is still saved in
924 		 * cb->s_dport.
925 		 */
926 		nsp->nsp_fport = 0;
927 		error = spp_output(cb, (struct mbuf *) 0);
928 		break;
929 
930 	case PRU_CONNECT2:
931 		error = EOPNOTSUPP;
932 		break;
933 
934 	/*
935 	 * We may decide later to implement connection closing
936 	 * handshaking at the spp level optionally.
937 	 * here is the hook to do it:
938 	 */
939 	case PRU_DISCONNECT:
940 		cb = spp_disconnect(cb);
941 		break;
942 
943 	/*
944 	 * Accept a connection.  Essentially all the work is
945 	 * done at higher levels; just return the address
946 	 * of the peer, storing through addr.
947 	 */
948 	case PRU_ACCEPT: {
949 		struct sockaddr_ns *sns = mtod(nam, struct sockaddr_ns *);
950 
951 		nam->m_len = sizeof (struct sockaddr_ns);
952 		sns->sns_family = AF_NS;
953 		sns->sns_addr = nsp->nsp_faddr;
954 		break;
955 		}
956 
957 	case PRU_SHUTDOWN:
958 		socantsendmore(so);
959 		cb = spp_usrclosed(cb);
960 		if (cb)
961 			error = spp_output(cb, (struct mbuf *) 0);
962 		break;
963 
964 	/*
965 	 * After a receive, possibly send acknowledgment
966 	 * updating allocation.
967 	 */
968 	case PRU_RCVD:
969 		(void) spp_output(cb, (struct mbuf *) 0);
970 		break;
971 
972 	case PRU_SEND:
973 		error = spp_output(cb, m);
974 		m = NULL;
975 		break;
976 
977 	case PRU_ABORT:
978 		(void) spp_drop(cb, ECONNABORTED);
979 		break;
980 
981 	case PRU_SENSE:
982 	case PRU_CONTROL:
983 		m = NULL;
984 		error = EOPNOTSUPP;
985 		break;
986 
987 	case PRU_RCVOOB:
988 		if ( ! (cb->s_oobflags & SF_IOOB) ) {
989 			error = EWOULDBLOCK;
990 			break;
991 		}
992 		m->m_len = 1;
993 		*mtod(m, caddr_t) = cb->s_iobc;
994 		cb->s_oobflags &= ~ SF_IOOB;
995 		break;
996 
997 	case PRU_SENDOOB:
998 		if (sbspace(&so->so_snd) < -512) {
999 			m_freem(m);
1000 			error = ENOBUFS;
1001 			break;
1002 		}
1003 		cb->s_oobflags |= SF_SOOB;
1004 		error = spp_output(cb, m);
1005 		m = NULL;
1006 		cb->s_oobflags &= ~SF_SOOB;
1007 		break;
1008 
1009 	case PRU_SOCKADDR:
1010 		ns_setsockaddr(nsp, nam);
1011 		break;
1012 
1013 	case PRU_PEERADDR:
1014 		ns_setpeeraddr(nsp, nam);
1015 		break;
1016 
1017 	case PRU_SLOWTIMO:
1018 		cb = spp_timers(cb, (int)nam);
1019 		break;
1020 
1021 	case PRU_FASTTIMO:
1022 	case PRU_PROTORCV:
1023 	case PRU_PROTOSEND:
1024 		error =  EOPNOTSUPP;
1025 		break;
1026 
1027 	default:
1028 		panic("sp_usrreq");
1029 	}
1030 	if (cb && (so->so_options & SO_DEBUG || traceallspps))
1031 		spp_trace(SA_USER, (u_char)ostate, cb, (struct spidp *)0, req);
1032 release:
1033 	if (m != NULL)
1034 		m_freem(m);
1035 	splx(s);
1036 	return (error);
1037 }
1038 
1039 spp_usrreq_sp(so, req, m, nam, rights)
1040 	struct socket *so;
1041 	int req;
1042 	struct mbuf *m, *nam, *rights;
1043 {
1044 	int error = spp_usrreq(so, req, m, nam, rights);
1045 
1046 	if (req==PRU_ATTACH && error==0) {
1047 		struct nspcb *nsp = sotonspcb(so);
1048 		((struct sppcb *)nsp->nsp_pcb)->s_flags |=
1049 					(SF_HI | SF_HO | SF_PI);
1050 	}
1051 	return (error);
1052 }
1053 
1054 /*
1055  * Create template to be used to send spp packets on a connection.
1056  * Called after host entry created, fills
1057  * in a skeletal spp header (choosing connection id),
1058  * minimizing the amount of work necessary when the connection is used.
1059  */
1060 spp_template(cb)
1061 	struct sppcb *cb;
1062 {
1063 	register struct nspcb *nsp = cb->s_nspcb;
1064 	register struct spidp *n = &(cb->s_shdr);
1065 
1066 	cb->s_mtu = 1024;
1067 	n->si_pt = NSPROTO_SPP;
1068 	n->si_sna = nsp->nsp_laddr;
1069 	n->si_dna = nsp->nsp_faddr;
1070 	n->si_sid = htons(spp_iss);
1071 	spp_iss += SPP_ISSINCR/2;
1072 	n->si_alo = 1;
1073 }
1074 
1075 /*
1076  * Close a SPIP control block:
1077  *	discard spp control block itself
1078  *	discard ns protocol control block
1079  *	wake up any sleepers
1080  */
1081 struct sppcb *
1082 spp_close(cb)
1083 	register struct sppcb *cb;
1084 {
1085 	register struct spidp_q *s;
1086 	struct nspcb *nsp = cb->s_nspcb;
1087 	struct socket *so = nsp->nsp_socket;
1088 	register struct mbuf *m;
1089 
1090 	s = cb->s_q.si_next;
1091 	while (s != &(cb->s_q)) {
1092 		s = s->si_next;
1093 		m = dtom(s->si_prev);
1094 		remque(s->si_prev);
1095 		m_freem(m);
1096 	}
1097 	(void) m_free(dtom(cb));
1098 	nsp->nsp_pcb = 0;
1099 	soisdisconnected(so);
1100 	ns_pcbdetach(nsp);
1101 	return ((struct sppcb *)0);
1102 }
1103 /*
1104  *	Someday we may do level 3 handshaking
1105  *	to close a connection or send a xerox style error.
1106  *	For now, just close.
1107  */
1108 struct sppcb *
1109 spp_usrclosed(cb)
1110 	register struct sppcb *cb;
1111 {
1112 	return (spp_close(cb));
1113 }
1114 struct sppcb *
1115 spp_disconnect(cb)
1116 	register struct sppcb *cb;
1117 {
1118 	return (spp_close(cb));
1119 }
1120 /*
1121  * Drop connection, reporting
1122  * the specified error.
1123  */
1124 struct sppcb *
1125 spp_drop(cb, errno)
1126 	register struct sppcb *cb;
1127 	int errno;
1128 {
1129 	struct socket *so = cb->s_nspcb->nsp_socket;
1130 
1131 	/*
1132 	 * someday, in the xerox world
1133 	 * we will generate error protocol packets
1134 	 * announcing that the socket has gone away.
1135 	 */
1136 	/*if (TCPS_HAVERCVDSYN(tp->t_state)) {
1137 		tp->t_state = TCPS_CLOSED;
1138 		(void) tcp_output(tp);
1139 	}*/
1140 	so->so_error = errno;
1141 	return (spp_close(cb));
1142 }
1143 
1144 spp_abort(nsp)
1145 	struct nspcb *nsp;
1146 {
1147 
1148 	(void) spp_close((struct sppcb *)nsp->nsp_pcb);
1149 }
1150 
1151 spp_setpersist(cb)
1152 	register struct sppcb *cb;
1153 {
1154 
1155 	/*if (cb->s_timer[TCPT_REXMT])
1156 		panic("spp_output REXMT");*/
1157 	/*
1158 	 * Start/restart persistance timer.
1159 	 */
1160 	TCPT_RANGESET(cb->s_timer[TCPT_PERSIST],
1161 	    ((int)(tcp_beta * cb->s_srtt)) << cb->s_rxtshift,
1162 	    TCPTV_PERSMIN, TCPTV_MAX);
1163 	cb->s_rxtshift++;
1164 	if (cb->s_rxtshift >= TCP_MAXRXTSHIFT)
1165 		cb->s_rxtshift = 0;
1166 }
1167 /*
1168  * Fast timeout routine for processing delayed acks
1169  */
1170 int spp_ftcnt;
1171 spp_fasttimo()
1172 {
1173 	register struct nspcb *nsp;
1174 	register struct sppcb *cb;
1175 	int s = splnet();
1176 
1177 	nsp = nspcb.nsp_next;
1178 	spp_ftcnt++;
1179 	if (nsp)
1180 	for (; nsp != &nspcb; nsp = nsp->nsp_next)
1181 		if ((cb = (struct sppcb *)nsp->nsp_pcb) &&
1182 		    (cb->s_flags & SF_DELACK)) {
1183 			cb->s_flags &= ~SF_DELACK;
1184 			cb->s_flags |= SF_AK;
1185 			(void) spp_output(cb, (struct mbuf *) 0);
1186 		}
1187 	splx(s);
1188 }
1189 
1190 /*
1191  * spp protocol timeout routine called every 500 ms.
1192  * Updates the timers in all active pcb's and
1193  * causes finite state machine actions if timers expire.
1194  */
1195 spp_slowtimo()
1196 {
1197 	register struct nspcb *ip, *ipnxt;
1198 	register struct sppcb *cb;
1199 	int s = splnet();
1200 	register int i;
1201 
1202 	/*
1203 	 * Search through tcb's and update active timers.
1204 	 */
1205 	ip = nspcb.nsp_next;
1206 	if (ip == 0) {
1207 		splx(s);
1208 		return;
1209 	}
1210 	while (ip != &nspcb) {
1211 		cb = nstosppcb(ip);
1212 		ipnxt = ip->nsp_next;
1213 		if (cb == 0)
1214 			goto tpgone;
1215 		for (i = 0; i < TCPT_NTIMERS; i++) {
1216 			if (cb->s_timer[i] && --cb->s_timer[i] == 0) {
1217 				(void) spp_usrreq(cb->s_nspcb->nsp_socket,
1218 				    PRU_SLOWTIMO, (struct mbuf *)0,
1219 				    (struct mbuf *)i, (struct mbuf *)0);
1220 				if (ipnxt->nsp_prev != ip)
1221 					goto tpgone;
1222 			}
1223 		}
1224 		cb->s_idle++;
1225 		if (cb->s_rtt)
1226 			cb->s_rtt++;
1227 tpgone:
1228 		ip = ipnxt;
1229 	}
1230 	spp_iss += SPP_ISSINCR/PR_SLOWHZ;		/* increment iss */
1231 	splx(s);
1232 }
1233 
1234 float	spp_backoff[TCP_MAXRXTSHIFT] =
1235     { 1.0, 1.2, 1.4, 1.7, 2.0, 3.0, 5.0, 8.0, 16.0, 32.0 };
1236 extern int tcpexprexmtbackoff;
1237 /*
1238  * TCP timer processing.
1239  */
1240 struct sppcb *
1241 spp_timers(cb, timer)
1242 	register struct sppcb *cb;
1243 	int timer;
1244 {
1245 
1246 	cb->s_force = 1 + timer;
1247 	switch (timer) {
1248 
1249 	/*
1250 	 * 2 MSL timeout in shutdown went off.  Delete connection
1251 	 * control block.
1252 	 */
1253 	case TCPT_2MSL:
1254 		cb = spp_close(cb);
1255 		break;
1256 
1257 	/*
1258 	 * Retransmission timer went off.  Message has not
1259 	 * been acked within retransmit interval.  Back off
1260 	 * to a longer retransmit interval and retransmit all
1261 	 * unacknowledged messages in the window.
1262 	 */
1263 	case TCPT_REXMT:
1264 		cb->s_rxtshift++;
1265 		if (cb->s_rxtshift > TCP_MAXRXTSHIFT) {
1266 			cb = spp_drop(cb, ETIMEDOUT);
1267 			break;
1268 		}
1269 		(void) spp_output(cb, (struct mbuf *) 0);
1270 		TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
1271 		    (int)cb->s_srtt, TCPTV_MIN, TCPTV_MAX);
1272 		if (tcpexprexmtbackoff) {
1273 			TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
1274 			    cb->s_timer[TCPT_REXMT] << cb->s_rxtshift,
1275 			    TCPTV_MIN, TCPTV_MAX);
1276 		} else {
1277 			TCPT_RANGESET(cb->s_timer[TCPT_REXMT],
1278 			    cb->s_timer[TCPT_REXMT] *
1279 			        spp_backoff[cb->s_rxtshift - 1],
1280 			    TCPTV_MIN, TCPTV_MAX);
1281 		}
1282 		break;
1283 
1284 	/*
1285 	 * Persistance timer into zero window.
1286 	 * Force a probe to be sent.
1287 	 */
1288 	case TCPT_PERSIST:
1289 		(void) spp_output(cb, (struct mbuf *) 0);
1290 		spp_setpersist(cb);
1291 		break;
1292 
1293 	/*
1294 	 * Keep-alive timer went off; send something
1295 	 * or drop connection if idle for too long.
1296 	 */
1297 	case TCPT_KEEP:
1298 		if (cb->s_state < TCPS_ESTABLISHED)
1299 			goto dropit;
1300 		if (cb->s_nspcb->nsp_socket->so_options & SO_KEEPALIVE) {
1301 		    	if (cb->s_idle >= TCPTV_MAXIDLE)
1302 				goto dropit;
1303 			(void) spp_output(cb, (struct mbuf *) 0);
1304 		} else
1305 			cb->s_idle = 0;
1306 		cb->s_timer[TCPT_KEEP] = TCPTV_KEEP;
1307 		break;
1308 	dropit:
1309 		cb = spp_drop(cb, ETIMEDOUT);
1310 		break;
1311 	}
1312 	return (cb);
1313 }
1314