1 /*	if_imp.c	4.6	82/02/16	*/
2 
3 #include "imp.h"
4 #if NIMP > 0
5 /*
6  * ARPAnet IMP interface driver.
7  *
8  * The IMP-host protocol is handled here, leaving
9  * hardware specifics to the lower level interface driver.
10  *
11  * TODO:
12  *	rethink coupling between this module and device driver
13  *	pass more error indications up to protocol modules
14  */
15 #include "../h/param.h"
16 #include "../h/systm.h"
17 #include "../h/mbuf.h"
18 #include "../h/pte.h"
19 #include "../h/buf.h"
20 #include "../h/protosw.h"
21 #include "../h/socket.h"
22 #include "../h/ubareg.h"
23 #include "../h/ubavar.h"
24 #include "../h/cpu.h"
25 #include "../h/mtpr.h"
26 #include "../h/vmmac.h"
27 #include "../net/in.h"
28 #include "../net/in_systm.h"
29 #include "../net/if.h"
30 #include "../net/if_imp.h"
31 #include "../net/if_imphost.h"
32 #include "../net/ip.h"
33 #include "../net/ip_var.h"
34 
35 /*
36  * IMP software status per interface.
37  * (partially shared with the hardware specific module)
38  *
39  * Each interface is referenced by a network interface structure,
40  * imp_if, which the routing code uses to locate the interface.
41  * This structure contains the output queue for the interface, its
42  * address, ...  IMP specific structures used in connecting the
43  * IMP software modules to the hardware specific interface routines
44  * are stored here.  The common structures are made visible to the
45  * interface driver by passing a pointer to the hardware routine
46  * at "attach" time.
47  *
48  * NOTE: imp_if and imp_cb are assumed adjacent in hardware code.
49  */
50 struct imp_softc {
51 	struct	ifnet imp_if;		/* network visible interface */
52 	struct	impcb imp_cb;		/* hooks to hardware module */
53 	u_char	imp_state;		/* current state of IMP */
54 	char	imp_dropcnt;		/* used during initialization */
55 } imp_softc[NIMP];
56 
57 /*
58  * Messages from IMP regarding why
59  * it's going down.
60  */
61 static char *impmsg[] = {
62 	"in 30 seconds",
63 	"for hardware PM",
64 	"to reload software",
65 	"for emergency reset"
66 };
67 
68 int	impdown(), impinit(), impoutput();
69 
70 /*
71  * IMP attach routine.  Called from hardware device attach routine
72  * at configuration time with a pointer to the UNIBUS device structure.
73  * Sets up local state and returns pointer to base of ifnet+impcb
74  * structures.  This is then used by the device's attach routine
75  * set up its back pointers.
76  */
77 impattach(ui)
78 	struct uba_device *ui;
79 {
80 	struct imp_softc *sc = &imp_softc[ui->ui_unit];
81 	register struct ifnet *ifp = &sc->imp_if;
82 
83 COUNT(IMPATTACH);
84 	/* UNIT COULD BE AMBIGUOUS */
85 	ifp->if_unit = ui->ui_unit;
86 	ifp->if_name = "imp";
87 	ifp->if_mtu = IMP_MTU;
88 	ifp->if_net = ui->ui_flags;
89 	/* this should be found by talking to the imp */
90 	ifp->if_addr = 0x4e00000a;;
91 	ifp->if_init = impinit;
92 	ifp->if_output = impoutput;
93 	/* reset is handled at the hardware level */
94 	if_attach(ifp);
95 	/* kludge to hand pointers back to hardware attach routine */
96 	return ((int)&sc->imp_if);
97 }
98 
99 /*
100  * IMP initialization routine: call hardware module to
101  * setup UNIBUS resources, init state and get ready for
102  * NOOPs the IMP should send us, and that we want to drop.
103  */
104 impinit(unit)
105 	int unit;
106 {
107 	register struct imp_softc *sc = &imp_softc[unit];
108 
109 	if ((*sc->imp_cb.ic_init)(unit) == 0) {
110 		sc->imp_state = IMPS_DOWN;
111 		return;
112 	}
113 	sc->imp_state = IMPS_INIT;
114 	sc->imp_dropcnt = IMP_DROPCNT;
115 	impnoops(sc);
116 }
117 
118 struct sockproto impproto = { PF_IMPLINK };
119 struct sockaddr_in impdst = { AF_IMPLINK };
120 struct sockaddr_in impsrc = { AF_IMPLINK };
121 
122 /*
123  * ARPAnet 1822 input routine.
124  * Called from hardware input interrupt routine to handle 1822
125  * IMP-host messages.  Type 0 messages (non-control) are
126  * passed to higher level protocol processors on the basis
127  * of link number.  Other type messages (control) are handled here.
128  */
129 impinput(unit, m)
130 	int unit;
131 	register struct mbuf *m;
132 {
133 	int s;
134 	register struct imp_leader *ip;
135 	register struct imp_softc *sc = &imp_softc[unit];
136 	register struct host *hp;
137 	register struct ifqueue *inq;
138 	struct control_leader *cp;
139 	struct in_addr addr;
140 
141 COUNT(IMP_INPUT);
142 	/*
143 	 * Verify leader length.  Be careful with control
144 	 * message which don't get a length included.
145 	 * We should generate a "bad leader" message
146 	 * to the IMP about messages too short.
147 	 */
148 	if (m->m_len < sizeof(struct control_leader) &&
149 	    (m = m_pullup(m, sizeof(struct control_leader))) == 0)
150 		return;
151 	cp = mtod(m, struct control_leader *);
152 	if (cp->dl_mtype == IMPTYPE_DATA)
153 		if (m->m_len < sizeof(struct imp_leader) &&
154 		    (m = m_pullup(m, sizeof(struct imp_leader))) == 0)
155 			return;
156 	ip = mtod(m, struct imp_leader *);
157 
158 	/*
159 	 * Check leader type -- should notify IMP
160 	 * in case of failure...
161 	 */
162 	if (ip->il_format != IMP_NFF) {
163 		sc->imp_if.if_collisions++;	/* XXX */
164 		goto drop;
165 	}
166 
167 	/*
168 	 * Certain messages require a host structure.
169 	 * Do this in one shot here.
170 	 */
171 	switch (ip->il_mtype) {
172 
173 	case IMPTYPE_RFNM:
174 	case IMPTYPE_INCOMPLETE:
175 	case IMPTYPE_HOSTDEAD:
176 	case IMPTYPE_HOSTUNREACH:
177 	case IMPTYPE_BADDATA:
178 #ifdef notdef
179 		addr.s_net = ip->il_network;
180 #else
181 		addr.s_net = 0;
182 #endif
183 		addr.s_imp = ip->il_imp;
184 		addr.s_host = ip->il_host;
185 		hp = hostlookup(addr);
186 		break;
187 	}
188 
189 	switch (ip->il_mtype) {
190 
191 	/*
192 	 * Data for a protocol.  Dispatch to the appropriate
193 	 * protocol routine (running at software interrupt).
194 	 * If this isn't a raw interface, advance pointer
195 	 * into mbuf past leader (done below).
196 	 */
197 	case IMPTYPE_DATA:
198 		ip->il_length =
199 			(ntohs(ip->il_length) >> 3) - sizeof(struct imp_leader);
200 		break;
201 
202 	/*
203 	 * IMP leader error.  Reset the IMP and discard the packet.
204 	 */
205 	case IMPTYPE_BADLEADER:
206 		/*
207 		 * According to 1822 document, this message
208 		 * will be generated in response to the
209 		 * first noop sent to the IMP after
210 		 * the host resets the IMP interface.
211 		 */
212 		if (sc->imp_state != IMPS_INIT) {
213 			imperr(sc, "leader error");
214 			hostreset(sc->imp_if.if_net);	/* XXX */
215 			impnoops(sc);
216 		}
217 		goto drop;
218 
219 	/*
220 	 * IMP going down.  Print message, and if not immediate,
221 	 * set off a timer to insure things will be reset at the
222 	 * appropriate time.
223 	 */
224 	case IMPTYPE_DOWN:
225 		if ((ip->il_link & IMP_DMASK) == 0) {
226 			sc->imp_state = IMPS_GOINGDOWN;
227 			timeout(impdown, sc, 30 * hz);
228 		}
229 		imperr(sc, "going down %s", impmsg[ip->il_link & IMP_DMASK]);
230 		goto drop;
231 
232 	/*
233 	 * A NOP usually seen during the initialization sequence.
234 	 * Compare the local address with that in the message.
235 	 * Reset the local address notion if it doesn't match.
236 	 */
237 	case IMPTYPE_NOOP: {
238 		register struct in_addr *sin;
239 
240 		if (sc->imp_state == IMPS_DOWN) {
241 			sc->imp_state = IMPS_INIT;
242 			sc->imp_dropcnt = IMP_DROPCNT;
243 		}
244 		if (sc->imp_state != IMPS_INIT)
245 			goto drop;
246 		if (--sc->imp_dropcnt > 0)
247 			goto drop;
248 		sc->imp_state = IMPS_UP;
249 		sin = &sc->imp_if.if_addr;
250 		sc->imp_if.if_host[0] = sin->s_host = ip->il_host;
251 		sin->s_imp = ip->il_imp;
252 		imperr(sc, "reset (host %d/imp %d)", ip->il_host,
253 			ntohs(ip->il_imp));
254 		/* restart output in case something was q'd */
255 		(*sc->imp_cb.ic_start)(sc->imp_if.if_unit);
256 		goto drop;
257 		}
258 
259 	/*
260 	 * RFNM or INCOMPLETE message, record in
261 	 * host table and prime output routine.
262 	 *
263 	 * SHOULD NOTIFY PROTOCOL ABOUT INCOMPLETES.
264 	 */
265 	case IMPTYPE_RFNM:
266 	case IMPTYPE_INCOMPLETE:
267 		if (hp && hp->h_rfnm) {
268 			register struct mbuf *n;
269 
270 			hp->h_rfnm--;
271 			/* poke holding queue */
272 			if (n = hp->h_q) {
273 				if (n->m_next == n)
274 					hp->h_q = 0;
275 				else {
276 					n = n->m_next;
277 					hp->h_q->m_next = n->m_next;
278 				}
279 				(void) impsnd(sc, n);
280 				break;
281 			}
282 			if (hp->h_rfnm == 0)
283 				hostfree(hp);
284 		}
285 		goto rawlinkin;
286 
287 	/*
288 	 * Host or IMP can't be reached.  Flush any packets
289 	 * awaiting transmission and release the host structure.
290 	 *
291 	 * TODO: NOTIFY THE PROTOCOL
292 	 */
293 	case IMPTYPE_HOSTDEAD:
294 		imperr(sc, "host dead");	/* XXX */
295 		goto common;			/* XXX */
296 
297 	/* SHOULD SIGNAL ROUTING DAEMON */
298 	case IMPTYPE_HOSTUNREACH:
299 		imperr(sc, "host unreachable");	/* XXX */
300 	common:
301 		if (hp)
302 			hostfree(hp);		/* won't work right */
303 		goto rawlinkin;
304 
305 	/*
306 	 * Error in data.  Clear RFNM status for this host and send
307 	 * noops to the IMP to clear the interface.
308 	 */
309 	case IMPTYPE_BADDATA:
310 		imperr(sc, "data error");
311 		if (hp)
312 			hp->h_rfnm = 0;
313 		impnoops(sc);
314 		goto rawlinkin;
315 
316 	/*
317 	 * Interface reset.
318 	 */
319 	case IMPTYPE_RESET:
320 		imperr(sc, "interface reset");
321 		impnoops(sc);
322 		goto drop;
323 
324 	default:
325 		sc->imp_if.if_collisions++;		/* XXX */
326 		goto drop;
327 	}
328 
329 	/*
330 	 * Queue on protocol's input queue.
331 	 */
332 	switch (ip->il_link) {
333 
334 #ifdef INET
335 	case IMPLINK_IP:
336 		m->m_len -= sizeof(struct imp_leader);
337 		m->m_off += sizeof(struct imp_leader);
338 		setipintr();
339 		inq = &ipintrq;
340 		break;
341 #endif
342 
343 	default:
344 rawlinkin:
345 		impproto.sp_protocol = ip->il_link;
346 		impdst.sin_addr = sc->imp_if.if_addr;
347 		impsrc.sin_addr.s_net = ip->il_network;
348 		impsrc.sin_addr.s_host = ip->il_host;
349 		impsrc.sin_addr.s_imp = ip->il_imp;
350 		raw_input(m, &impproto, &impdst, &impsrc);
351 		return;
352 	}
353 	IF_ENQUEUE(inq, m);
354 	return;
355 
356 drop:
357 	m_freem(m);
358 }
359 
360 /*
361  * Bring the IMP down after notification.
362  */
363 impdown(sc)
364 	struct imp_softc *sc;
365 {
366 	sc->imp_state = IMPS_DOWN;
367 	imperr(sc, "marked down");
368 	/* notify protocols with messages waiting? */
369 }
370 
371 /*VARARGS*/
372 imperr(sc, fmt, a1, a2)
373 	struct imp_softc *sc;
374 	char *fmt;
375 {
376 	printf("imp%d: ", sc->imp_if.if_unit);
377 	printf(fmt, a1, a2);
378 	printf("\n");
379 }
380 
381 /*
382  * ARPAnet 1822 output routine.
383  * Called from higher level protocol routines to set up messages for
384  * transmission to the imp.  Sets up the header and calls impsnd to
385  * enqueue the message for this IMP's hardware driver.
386  */
387 impoutput(ifp, m0, pf)
388 	register struct ifnet *ifp;
389 	struct mbuf *m0;
390 {
391 	register struct imp_leader *imp;
392 	register struct mbuf *m = m0;
393 	int x, dhost, dimp, dlink, len, dnet;
394 
395 COUNT(IMPOUTPUT);
396 #ifdef notdef
397 	/*
398 	 * Don't even try if the IMP is unavailable.
399 	 */
400 	x = imp_softc[ifp->if_unit].imp_state;
401 	if (x == IMPS_DOWN || x == IMPS_GOINGDOWN)
402 		goto drop;
403 #endif
404 
405 	switch (pf) {
406 
407 #ifdef INET
408 	case PF_INET: {
409 		register struct ip *ip = mtod(m0, struct ip *);
410 
411 		dnet = ip->ip_dst.s_net;
412 		dhost = ip->ip_dst.s_host;
413 		dimp = ip->ip_dst.s_imp;
414 		dlink = IMPLINK_IP;
415 		len = ntohs(ip->ip_len);
416 		break;
417 	}
418 #endif
419 	case PF_IMPLINK:
420 		goto leaderexists;
421 
422 	default:
423 		printf("imp%d: can't encapsulate pf%d\n", ifp->if_unit, pf);
424 		goto drop;
425 	}
426 
427 	/*
428 	 * Add IMP leader.  If there's not enough space in the
429 	 * first mbuf, allocate another.  If that should fail, we
430 	 * drop this sucker.
431 	 */
432 	if (m->m_off > MMAXOFF ||
433 	    MMINOFF + sizeof(struct imp_leader) > m->m_off) {
434 		m = m_get(M_DONTWAIT);
435 		if (m == 0)
436 			goto drop;
437 		m->m_next = m0;
438 		m->m_off = MMINOFF;
439 		m->m_len = sizeof(struct imp_leader);
440 	} else {
441 		m->m_off -= sizeof(struct imp_leader);
442 		m->m_len += sizeof(struct imp_leader);
443 	}
444 	imp = mtod(m, struct imp_leader *);
445 	imp->il_format = IMP_NFF;
446 	imp->il_mtype = IMPTYPE_DATA;
447 	imp->il_network = dnet;
448 	imp->il_host = dhost;
449 	imp->il_imp = dimp;
450 	imp->il_length = htons((len + sizeof(struct imp_leader)) << 3);
451 	imp->il_link = dlink;
452 	imp->il_flags = imp->il_htype = imp->il_subtype = 0;
453 
454 leaderexists:
455 	/*
456 	 * Hand message to impsnd to perform RFNM counting
457 	 * and eventual transmission.
458 	 */
459 	return (impsnd(ifp, m));
460 drop:
461 	m_freem(m0);
462 	return (0);
463 }
464 
465 /*
466  * Put a message on an interface's output queue.
467  * Perform RFNM counting: no more than 8 message may be
468  * in flight to any one host.
469  */
470 impsnd(ifp, m)
471 	struct ifnet *ifp;
472 	struct mbuf *m;
473 {
474 	register struct imp_leader *ip;
475 	register struct host *hp;
476 	struct impcb *icp;
477 	int x;
478 
479 COUNT(IMPSND);
480 	ip = mtod(m, struct imp_leader *);
481 
482 	/*
483 	 * Do RFNM counting for data messages
484 	 * (no more than 8 outstanding to any host)
485 	 */
486 	if (ip->il_mtype == IMPTYPE_DATA) {
487 		struct in_addr addr;
488 
489 #ifdef notdef
490                 addr.s_net = ip->il_network;
491 #else
492 		addr.s_net = 0;
493 #endif
494                 addr.s_host = ip->il_host;
495                 addr.s_imp = ip->il_imp;
496 		x = splimp();
497 		if ((hp = hostlookup(addr)) == 0)
498 			hp = hostenter(addr);
499 
500 		/*
501 		 * If IMP would block, queue until RFNM
502 		 */
503 		if (hp) {
504 			register struct mbuf *n;
505 			int cnt;
506 
507 			if (hp->h_rfnm < 8) {
508 				hp->h_rfnm++;
509 				splx(x);
510 				goto enque;
511 			}
512 			/*
513 			 * Keeping the count in the host structure
514 			 * causes the packing scheme to lose too much.
515 			 */
516 			cnt = 0;
517 			if (n = hp->h_q)
518 				for (; n != hp->h_q; n = n->m_next)
519 					cnt++;
520 			if (cnt >= 8)
521 				goto drop;
522 
523 			/*
524 			 * Q is kept as circular list with h_q
525 			 * (head) pointing to the last entry.
526 			 */
527 			if ((n = hp->h_q) == 0)
528 				hp->h_q = m->m_next = m;
529 			else {
530 				m->m_next = n->m_next;
531 				hp->h_q = n->m_next = m;
532 			}
533 			splx(x);
534 			goto start;
535 		}
536 drop:
537 		m_freem(m);
538 		splx(x);
539 		return (0);
540 	}
541 enque:
542         x = splimp();
543 	IF_ENQUEUE(&ifp->if_snd, m);
544 	splx(x);
545 
546 start:
547 	icp = &imp_softc[ifp->if_unit].imp_cb;
548 	if (icp->ic_oactive == 0)
549 		(*icp->ic_start)(ifp->if_unit);
550 	return (1);
551 }
552 
553 /*
554  * Put three 1822 NOOPs at the head of the output queue.
555  * Part of host-IMP initialization procedure.
556  * (Should return success/failure, but noone knows
557  * what to do with this, so why bother?)
558  */
559 impnoops(sc)
560 	register struct imp_softc *sc;
561 {
562 	register i;
563 	register struct mbuf *m;
564 	register struct control_leader *cp;
565 	int x;
566 
567 COUNT(IMPNOOPS);
568 	sc->imp_state = IMPS_INIT;
569 	sc->imp_dropcnt = IMP_DROPCNT;
570 	for (i = 0; i < IMP_DROPCNT + 1; i++ ) {
571 		if ((m = m_getclr(M_DONTWAIT)) == 0)
572 			return;
573 		m->m_off = MMINOFF;
574 		m->m_len = sizeof(struct control_leader);
575 		cp = mtod(m, struct control_leader *);
576 		cp->dl_format = IMP_NFF;
577                 cp->dl_link = i;
578                 cp->dl_mtype = IMPTYPE_NOOP;
579 		x = splimp();
580 		IF_PREPEND(&sc->imp_if.if_snd, m);
581 		splx(x);
582 	}
583 	if (sc->imp_cb.ic_oactive == 0)
584 		(*sc->imp_cb.ic_start)(sc->imp_if.if_unit);
585 }
586 
587 #ifdef IMPLEADERS
588 printleader(routine, ip)
589 	char *routine;
590 	register struct imp_leader *ip;
591 {
592 	printf("%s: ", routine);
593 	printbyte((char *)ip, 12);
594 	printf("<fmt=%x,net=%x,flags=%x,mtype=", ip->il_format, ip->il_network,
595 		ip->il_flags);
596 	if (ip->il_mtype <= IMPTYPE_READY)
597 		printf("%s,", impleaders[ip->il_mtype]);
598 	else
599 		printf("%x,", ip->il_mtype);
600 	printf("htype=%x,host=%x,imp=%x,link=", ip->il_htype, ip->il_host,
601 		ip->il_impno);
602 	if (ip->il_link == IMPLINK_IP)
603 		printf("ip,");
604 	else
605 		printf("%x,", ip->il_link);
606 	printf("subtype=%x,len=%x>\n",ip->il_subtype,ntohs(ip->il_length)>>3);
607 }
608 
609 printbyte(cp, n)
610 	register char *cp;
611 	int n;
612 {
613 	register i, j, c;
614 
615 	for (i=0; i<n; i++) {
616 		c = *cp++;
617 		for (j=0; j<2; j++)
618 			putchar("0123456789abcdef"[(c>>((1-j)*4))&0xf]);
619 		putchar(' ');
620 	}
621 	putchar('\n');
622 }
623 #endif
624 #endif
625