xref: /original-bsd/sys/deprecated/netimp/if_imp.c (revision 460057e1)
1 /*	if_imp.c	4.13	82/03/12	*/
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 *impmessage[] = {
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 	/* the host and imp fields will be filled in by the imp */
90 	ifp->if_addr = if_makeaddr(ifp->if_net, 0);
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 	register struct imp_leader *ip;
134 	register struct imp_softc *sc = &imp_softc[unit];
135 	register struct host *hp;
136 	register struct ifqueue *inq;
137 	struct control_leader *cp;
138 	struct in_addr addr;
139 	struct mbuf *next;
140 
141 COUNT(IMPINPUT);
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 			impmsg(sc, "leader error");
214 			hostreset(sc->imp_if.if_net);	/* XXX */
215 			impnoops(sc);
216 		}
217 		goto rawlinkin;
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 		impmsg(sc, "going down %s", impmessage[ip->il_link&IMP_DMASK]);
230 		goto rawlinkin;
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 || --sc->imp_dropcnt > 0)
245 			goto rawlinkin;
246 		sc->imp_state = IMPS_UP;
247 		sin = &sc->imp_if.if_addr;
248 		sc->imp_if.if_host[0] = sin->s_host = ip->il_host;
249 		sin->s_imp = ip->il_imp;
250 		impmsg(sc, "reset (host %d/imp %d)", ip->il_host,
251 			ntohs(ip->il_imp));
252 		/* restart output in case something was q'd */
253 		(*sc->imp_cb.ic_start)(sc->imp_if.if_unit);
254 		goto rawlinkin;
255 	}
256 
257 	/*
258 	 * RFNM or INCOMPLETE message, record in
259 	 * host table and prime output routine.
260 	 *
261 	 * SHOULD NOTIFY PROTOCOL ABOUT INCOMPLETES.
262 	 */
263 	case IMPTYPE_RFNM:
264 	case IMPTYPE_INCOMPLETE:
265 		if (hp && hp->h_rfnm)
266 			if (next = hostdeque(hp))
267 				(void) impsnd(sc, next);
268 		goto rawlinkin;
269 
270 	/*
271 	 * Host or IMP can't be reached.  Flush any packets
272 	 * awaiting transmission and release the host structure.
273 	 *
274 	 * TODO: NOTIFY THE PROTOCOL
275 	 */
276 	case IMPTYPE_HOSTDEAD:
277 		impmsg(sc, "host dead");	/* XXX */
278 		goto common;			/* XXX */
279 
280 	/* SHOULD SIGNAL ROUTING DAEMON */
281 	case IMPTYPE_HOSTUNREACH:
282 		impmsg(sc, "host unreachable");	/* XXX */
283 	common:
284 		if (hp)
285 			hostfree(hp);		/* won't work right */
286 		goto rawlinkin;
287 
288 	/*
289 	 * Error in data.  Clear RFNM status for this host and send
290 	 * noops to the IMP to clear the interface.
291 	 */
292 	case IMPTYPE_BADDATA:
293 		impmsg(sc, "data error");
294 		if (hp)
295 			hp->h_rfnm = 0;
296 		impnoops(sc);
297 		goto rawlinkin;
298 
299 	/*
300 	 * Interface reset.
301 	 */
302 	case IMPTYPE_RESET:
303 		impmsg(sc, "interface reset");
304 		impnoops(sc);
305 		goto rawlinkin;
306 
307 	default:
308 		sc->imp_if.if_collisions++;		/* XXX */
309 		goto rawlinkin;
310 	}
311 
312 	/*
313 	 * Queue on protocol's input queue.
314 	 */
315 	switch (ip->il_link) {
316 
317 #ifdef INET
318 	case IMPLINK_IP:
319 		m->m_len -= sizeof(struct imp_leader);
320 		m->m_off += sizeof(struct imp_leader);
321 		setipintr();
322 		inq = &ipintrq;
323 		break;
324 #endif
325 
326 	default:
327 	rawlinkin:
328 		impproto.sp_protocol = ip->il_link;
329 		impdst.sin_addr = sc->imp_if.if_addr;
330 		impsrc.sin_addr.s_net = ip->il_network;
331 		impsrc.sin_addr.s_host = ip->il_host;
332 		impsrc.sin_addr.s_imp = ip->il_imp;
333 		raw_input(m, &impproto, &impdst, &impsrc);
334 		return;
335 	}
336 	IF_ENQUEUE(inq, m);
337 	return;
338 
339 drop:
340 	m_freem(m);
341 }
342 
343 /*
344  * Bring the IMP down after notification.
345  */
346 impdown(sc)
347 	struct imp_softc *sc;
348 {
349 	sc->imp_state = IMPS_DOWN;
350 	impmsg(sc, "marked down");
351 	/* notify protocols with messages waiting? */
352 }
353 
354 /*VARARGS*/
355 impmsg(sc, fmt, a1, a2)
356 	struct imp_softc *sc;
357 	char *fmt;
358 {
359 	printf("imp%d: ", sc->imp_if.if_unit);
360 	printf(fmt, a1, a2);
361 	printf("\n");
362 }
363 
364 /*
365  * ARPAnet 1822 output routine.
366  * Called from higher level protocol routines to set up messages for
367  * transmission to the imp.  Sets up the header and calls impsnd to
368  * enqueue the message for this IMP's hardware driver.
369  */
370 impoutput(ifp, m0, pf)
371 	register struct ifnet *ifp;
372 	struct mbuf *m0;
373 {
374 	register struct imp_leader *imp;
375 	register struct mbuf *m = m0;
376 	int x, dhost, dimp, dlink, len;
377 
378 COUNT(IMPOUTPUT);
379 	/*
380 	 * Don't even try if the IMP is unavailable.
381 	 */
382 	x = imp_softc[ifp->if_unit].imp_state;
383 	if (x == IMPS_DOWN || x == IMPS_GOINGDOWN)
384 		goto drop;
385 
386 	switch (pf) {
387 
388 #ifdef INET
389 	case PF_INET: {
390 		register struct ip *ip = mtod(m0, struct ip *);
391 
392 		dhost = ip->ip_dst.s_host;
393 		dimp = ip->ip_dst.s_imp;
394 		dlink = IMPLINK_IP;
395 		len = ntohs(ip->ip_len);
396 		break;
397 	}
398 #endif
399 	case PF_IMPLINK:
400 		goto leaderexists;
401 
402 	default:
403 		printf("imp%d: can't encapsulate pf%d\n", ifp->if_unit, pf);
404 		goto drop;
405 	}
406 
407 	/*
408 	 * Add IMP leader.  If there's not enough space in the
409 	 * first mbuf, allocate another.  If that should fail, we
410 	 * drop this sucker.
411 	 */
412 	if (m->m_off > MMAXOFF ||
413 	    MMINOFF + sizeof(struct imp_leader) > m->m_off) {
414 		m = m_get(M_DONTWAIT);
415 		if (m == 0)
416 			goto drop;
417 		m->m_next = m0;
418 		m->m_off = MMINOFF;
419 		m->m_len = sizeof(struct imp_leader);
420 	} else {
421 		m->m_off -= sizeof(struct imp_leader);
422 		m->m_len += sizeof(struct imp_leader);
423 	}
424 	imp = mtod(m, struct imp_leader *);
425 	imp->il_format = IMP_NFF;
426 	imp->il_mtype = IMPTYPE_DATA;
427 	imp->il_network = 0;
428 	imp->il_host = dhost;
429 	imp->il_imp = dimp;
430 	imp->il_length = htons((len + sizeof(struct imp_leader)) << 3);
431 	imp->il_link = dlink;
432 	imp->il_flags = imp->il_htype = imp->il_subtype = 0;
433 
434 leaderexists:
435 	/*
436 	 * Hand message to impsnd to perform RFNM counting
437 	 * and eventual transmission.
438 	 */
439 	return (impsnd(ifp, m));
440 drop:
441 	m_freem(m0);
442 	return (0);
443 }
444 
445 /*
446  * Put a message on an interface's output queue.
447  * Perform RFNM counting: no more than 8 message may be
448  * in flight to any one host.
449  */
450 impsnd(ifp, m)
451 	struct ifnet *ifp;
452 	struct mbuf *m;
453 {
454 	register struct imp_leader *ip;
455 	register struct host *hp;
456 	struct impcb *icp;
457 	int x;
458 
459 COUNT(IMPSND);
460 	ip = mtod(m, struct imp_leader *);
461 
462 	/*
463 	 * Do RFNM counting for data messages
464 	 * (no more than 8 outstanding to any host)
465 	 */
466 	x = splimp();
467 	if (ip->il_mtype == IMPTYPE_DATA) {
468 		struct in_addr addr;
469 
470 #ifdef notdef
471                 addr.s_net = ip->il_network;
472 #else
473 		addr.s_net = 0;
474 #endif
475                 addr.s_host = ip->il_host;
476                 addr.s_imp = ip->il_imp;
477 		if ((hp = hostlookup(addr)) == 0)
478 			hp = hostenter(addr);
479 
480 		/*
481 		 * If IMP would block, queue until RFNM
482 		 */
483 		if (hp) {
484 			if (hp->h_rfnm < 8) {
485 				hp->h_rfnm++;
486 				goto enque;
487 			}
488 			if (hp->h_qcnt < 8) {	/* high water mark */
489 				HOST_ENQUE(hp, m);
490 				goto start;
491 			}
492 		}
493 		m_freem(m);
494 		splx(x);
495 		return (0);
496 	}
497 enque:
498 	IF_ENQUEUE(&ifp->if_snd, m);
499 start:
500 	splx(x);
501 	icp = &imp_softc[ifp->if_unit].imp_cb;
502 	if (icp->ic_oactive == 0)
503 		(*icp->ic_start)(ifp->if_unit);
504 	return (1);
505 }
506 
507 /*
508  * Put three 1822 NOOPs at the head of the output queue.
509  * Part of host-IMP initialization procedure.
510  * (Should return success/failure, but noone knows
511  * what to do with this, so why bother?)
512  */
513 impnoops(sc)
514 	register struct imp_softc *sc;
515 {
516 	register i;
517 	register struct mbuf *m;
518 	register struct control_leader *cp;
519 	int x;
520 
521 COUNT(IMPNOOPS);
522 	sc->imp_state = IMPS_INIT;
523 	sc->imp_dropcnt = IMP_DROPCNT;
524 	for (i = 0; i < IMP_DROPCNT + 1; i++ ) {
525 		if ((m = m_getclr(M_DONTWAIT)) == 0)
526 			return;
527 		m->m_off = MMINOFF;
528 		m->m_len = sizeof(struct control_leader);
529 		cp = mtod(m, struct control_leader *);
530 		cp->dl_format = IMP_NFF;
531                 cp->dl_link = i;
532                 cp->dl_mtype = IMPTYPE_NOOP;
533 		x = splimp();
534 		IF_PREPEND(&sc->imp_if.if_snd, m);
535 		splx(x);
536 	}
537 	if (sc->imp_cb.ic_oactive == 0)
538 		(*sc->imp_cb.ic_start)(sc->imp_if.if_unit);
539 }
540 
541 #ifdef IMPLEADERS
542 printleader(routine, ip)
543 	char *routine;
544 	register struct imp_leader *ip;
545 {
546 	printf("%s: ", routine);
547 	printbyte((char *)ip, 12);
548 	printf("<fmt=%x,net=%x,flags=%x,mtype=", ip->il_format, ip->il_network,
549 		ip->il_flags);
550 	if (ip->il_mtype <= IMPTYPE_READY)
551 		printf("%s,", impleaders[ip->il_mtype]);
552 	else
553 		printf("%x,", ip->il_mtype);
554 	printf("htype=%x,host=%x,imp=%x,link=", ip->il_htype, ip->il_host,
555 		ip->il_impno);
556 	if (ip->il_link == IMPLINK_IP)
557 		printf("ip,");
558 	else
559 		printf("%x,", ip->il_link);
560 	printf("subtype=%x,len=%x>\n",ip->il_subtype,ntohs(ip->il_length)>>3);
561 }
562 
563 printbyte(cp, n)
564 	register char *cp;
565 	int n;
566 {
567 	register i, j, c;
568 
569 	for (i=0; i<n; i++) {
570 		c = *cp++;
571 		for (j=0; j<2; j++)
572 			putchar("0123456789abcdef"[(c>>((1-j)*4))&0xf]);
573 		putchar(' ');
574 	}
575 	putchar('\n');
576 }
577 #endif
578 #endif
579