xref: /netbsd-src/sys/net/if_arcsubr.c (revision d909946ca08dceb44d7d0f22ec9488679695d976)
1 /*	$NetBSD: if_arcsubr.c,v 1.73 2016/04/28 14:40:09 ozaki-r Exp $	*/
2 
3 /*
4  * Copyright (c) 1994, 1995 Ignatios Souvatzis
5  * Copyright (c) 1982, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * from: NetBSD: if_ethersubr.c,v 1.9 1994/06/29 06:36:11 cgd Exp
33  *       @(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
34  *
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: if_arcsubr.c,v 1.73 2016/04/28 14:40:09 ozaki-r Exp $");
39 
40 #ifdef _KERNEL_OPT
41 #include "opt_inet.h"
42 #endif
43 
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/protosw.h>
50 #include <sys/socket.h>
51 #include <sys/ioctl.h>
52 #include <sys/errno.h>
53 #include <sys/syslog.h>
54 
55 #include <sys/cpu.h>
56 
57 #include <net/if.h>
58 #include <net/netisr.h>
59 #include <net/route.h>
60 #include <net/if_dl.h>
61 #include <net/if_types.h>
62 #include <net/if_arc.h>
63 #include <net/if_arp.h>
64 #include <net/if_ether.h>
65 
66 #include <net/bpf.h>
67 
68 #ifdef INET
69 #include <netinet/in.h>
70 #include <netinet/in_var.h>
71 #include <netinet/if_inarp.h>
72 #endif
73 
74 #ifdef INET6
75 #ifndef INET
76 #include <netinet/in.h>
77 #endif
78 #include <netinet6/in6_var.h>
79 #include <netinet6/nd6.h>
80 #endif
81 
82 #define ARCNET_ALLOW_BROKEN_ARP
83 
84 #ifndef ARC_IPMTU
85 #define ARC_IPMTU	1500
86 #endif
87 
88 static struct mbuf *arc_defrag(struct ifnet *, struct mbuf *);
89 
90 /*
91  * RC1201 requires us to have this configurable. We have it only per
92  * machine at the moment... there is no generic "set mtu" ioctl, AFAICS.
93  * Anyway, it is possible to binpatch this or set it per kernel config
94  * option.
95  */
96 #if ARC_IPMTU > 60480
97 ERROR: The arc_ipmtu is ARC_IPMTU, but must not exceed 60480.
98 #endif
99 int arc_ipmtu = ARC_IPMTU;
100 uint8_t  arcbroadcastaddr = 0;
101 
102 #define senderr(e) { error = (e); goto bad;}
103 
104 static	int arc_output(struct ifnet *, struct mbuf *,
105 	    const struct sockaddr *, const struct rtentry *);
106 static	void arc_input(struct ifnet *, struct mbuf *);
107 
108 /*
109  * ARCnet output routine.
110  * Encapsulate a packet of type family for the local net.
111  * Assumes that ifp is actually pointer to arccom structure.
112  */
113 static int
114 arc_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
115     const struct rtentry *rt)
116 {
117 	struct mbuf		*m, *m1, *mcopy;
118 	struct arccom		*ac;
119 	const struct arc_header	*cah;
120 	struct arc_header	*ah;
121 	struct arphdr		*arph;
122 	int			error, newencoding;
123 	uint8_t			atype, adst, myself;
124 	int			tfrags, sflag, fsflag, rsflag;
125 
126 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
127 		return (ENETDOWN); /* m, m1 aren't initialized yet */
128 
129 	error = newencoding = 0;
130 	ac = (struct arccom *)ifp;
131 	m = m0;
132 	mcopy = m1 = NULL;
133 
134 	myself = *CLLADDR(ifp->if_sadl);
135 
136 	/*
137 	 * if the queueing discipline needs packet classification,
138 	 * do it before prepending link headers.
139 	 */
140 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
141 
142 	switch (dst->sa_family) {
143 #ifdef INET
144 	case AF_INET:
145 
146 		/*
147 		 * For now, use the simple IP addr -> ARCnet addr mapping
148 		 */
149 		if (m->m_flags & (M_BCAST|M_MCAST))
150 			adst = arcbroadcastaddr; /* ARCnet broadcast address */
151 		else if (ifp->if_flags & IFF_NOARP)
152 			adst = ntohl(satocsin(dst)->sin_addr.s_addr) & 0xFF;
153 		else if ((error = arpresolve(ifp, rt, m, dst, &adst,
154 		    sizeof(adst))) != 0)
155 			return error == EWOULDBLOCK ? 0 : error;
156 
157 		/* If broadcasting on a simplex interface, loopback a copy */
158 		if ((m->m_flags & (M_BCAST|M_MCAST)) &&
159 		    (ifp->if_flags & IFF_SIMPLEX))
160 			mcopy = m_copy(m, 0, (int)M_COPYALL);
161 		if (ifp->if_flags & IFF_LINK0) {
162 			atype = ARCTYPE_IP;
163 			newencoding = 1;
164 		} else {
165 			atype = ARCTYPE_IP_OLD;
166 			newencoding = 0;
167 		}
168 		break;
169 
170 	case AF_ARP:
171 		arph = mtod(m, struct arphdr *);
172 		if (m->m_flags & M_BCAST)
173 			adst = arcbroadcastaddr;
174 		else {
175 			uint8_t *tha = ar_tha(arph);
176 			if (tha == NULL)
177 				return 0;
178 			adst = *tha;
179 		}
180 
181 		arph->ar_hrd = htons(ARPHRD_ARCNET);
182 
183 		switch (ntohs(arph->ar_op)) {
184 		case ARPOP_REVREQUEST:
185 		case ARPOP_REVREPLY:
186 			if (!(ifp->if_flags & IFF_LINK0)) {
187 				printf("%s: can't handle af%d\n",
188 				    ifp->if_xname, dst->sa_family);
189 				senderr(EAFNOSUPPORT);
190 			}
191 
192 			atype = htons(ARCTYPE_REVARP);
193 			newencoding = 1;
194 			break;
195 
196 		case ARPOP_REQUEST:
197 		case ARPOP_REPLY:
198 		default:
199 			if (ifp->if_flags & IFF_LINK0) {
200 				atype = htons(ARCTYPE_ARP);
201 				newencoding = 1;
202 			} else {
203 				atype = htons(ARCTYPE_ARP_OLD);
204 				newencoding = 0;
205 			}
206 		}
207 #ifdef ARCNET_ALLOW_BROKEN_ARP
208 		/*
209 		 * XXX It's not clear per RFC826 if this is needed, but
210 		 * "assigned numbers" say this is wrong.
211 		 * However, e.g., AmiTCP 3.0Beta used it... we make this
212 		 * switchable for emergency cases. Not perfect, but...
213 		 */
214 		if (ifp->if_flags & IFF_LINK2)
215 			arph->ar_pro = atype - 1;
216 #endif
217 		break;
218 #endif
219 #ifdef INET6
220 	case AF_INET6:
221 		if (!nd6_storelladdr(ifp, rt, m, dst, &adst, sizeof(adst)))
222 			return (0); /* it must be impossible, but... */
223 		atype = htons(ARCTYPE_INET6);
224 		newencoding = 1;
225 		break;
226 #endif
227 
228 	case AF_UNSPEC:
229 		cah = (const struct arc_header *)dst->sa_data;
230  		adst = cah->arc_dhost;
231 		atype = cah->arc_type;
232 		break;
233 
234 	default:
235 		printf("%s: can't handle af%d\n", ifp->if_xname,
236 		    dst->sa_family);
237 		senderr(EAFNOSUPPORT);
238 	}
239 
240 	if (mcopy)
241 		(void) looutput(ifp, mcopy, dst, rt);
242 
243 	/*
244 	 * Add local net header.  If no space in first mbuf,
245 	 * allocate another.
246 	 *
247 	 * For ARCnet, this is just symbolic. The header changes
248 	 * form and position on its way into the hardware and out of
249 	 * the wire.  At this point, it contains source, destination and
250 	 * packet type.
251 	 */
252 	if (newencoding) {
253 		++ac->ac_seqid; /* make the seqid unique */
254 
255 		tfrags = (m->m_pkthdr.len + 503) / 504;
256 		fsflag = 2 * tfrags - 3;
257 		sflag = 0;
258 		rsflag = fsflag;
259 
260 		while (sflag < fsflag) {
261 			/* we CAN'T have short packets here */
262 			m1 = m_split(m, 504, M_DONTWAIT);
263 			if (m1 == 0)
264 				senderr(ENOBUFS);
265 
266 			M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT);
267 			if (m == 0)
268 				senderr(ENOBUFS);
269 			ah = mtod(m, struct arc_header *);
270 			ah->arc_type = atype;
271 			ah->arc_dhost = adst;
272 			ah->arc_shost = myself;
273 			ah->arc_flag = rsflag;
274 			ah->arc_seqid = ac->ac_seqid;
275 
276 			if ((error = ifq_enqueue(ifp, m)) != 0)
277 				return (error);
278 
279 			m = m1;
280 			sflag += 2;
281 			rsflag = sflag;
282 		}
283 		m1 = NULL;
284 
285 
286 		/* here we can have small, especially forbidden packets */
287 
288 		if ((m->m_pkthdr.len >=
289 		    ARC_MIN_FORBID_LEN - ARC_HDRNEWLEN + 2) &&
290 		    (m->m_pkthdr.len <=
291 		    ARC_MAX_FORBID_LEN - ARC_HDRNEWLEN + 2)) {
292 
293 			M_PREPEND(m, ARC_HDRNEWLEN_EXC, M_DONTWAIT);
294 			if (m == 0)
295 				senderr(ENOBUFS);
296 			ah = mtod(m, struct arc_header *);
297 			ah->arc_flag = 0xFF;
298 			ah->arc_seqid = 0xFFFF;
299 			ah->arc_type2 = atype;
300 			ah->arc_flag2 = sflag;
301 			ah->arc_seqid2 = ac->ac_seqid;
302 		} else {
303 			M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT);
304 			if (m == 0)
305 				senderr(ENOBUFS);
306 			ah = mtod(m, struct arc_header *);
307 			ah->arc_flag = sflag;
308 			ah->arc_seqid = ac->ac_seqid;
309 		}
310 
311 		ah->arc_dhost = adst;
312 		ah->arc_shost = myself;
313 		ah->arc_type = atype;
314 	} else {
315 		M_PREPEND(m, ARC_HDRLEN, M_DONTWAIT);
316 		if (m == 0)
317 			senderr(ENOBUFS);
318 		ah = mtod(m, struct arc_header *);
319 		ah->arc_type = atype;
320 		ah->arc_dhost = adst;
321 		ah->arc_shost = myself;
322 	}
323 
324 	return ifq_enqueue(ifp, m);
325 
326 bad:
327 	if (m1)
328 		m_freem(m1);
329 	if (m)
330 		m_freem(m);
331 	return (error);
332 }
333 
334 /*
335  * Defragmenter. Returns mbuf if last packet found, else
336  * NULL. frees imcoming mbuf as necessary.
337  */
338 
339 static struct mbuf *
340 arc_defrag(struct ifnet *ifp, struct mbuf *m)
341 {
342 	struct arc_header *ah, *ah1;
343 	struct arccom *ac;
344 	struct ac_frag *af;
345 	struct mbuf *m1;
346 	const char *s;
347 	int newflen;
348 	u_char src, dst, typ;
349 
350 	ac = (struct arccom *)ifp;
351 
352 	if (m->m_len < ARC_HDRNEWLEN) {
353 		m = m_pullup(m, ARC_HDRNEWLEN);
354 		if (m == NULL) {
355 			++ifp->if_ierrors;
356 			return NULL;
357 		}
358 	}
359 
360 	ah = mtod(m, struct arc_header *);
361 	typ = ah->arc_type;
362 
363 	if (!arc_isphds(typ))
364 		return m;
365 
366 	src = ah->arc_shost;
367 	dst = ah->arc_dhost;
368 
369 	if (ah->arc_flag == 0xff) {
370 		m_adj(m, 4);
371 
372 		if (m->m_len < ARC_HDRNEWLEN) {
373 			m = m_pullup(m, ARC_HDRNEWLEN);
374 			if (m == NULL) {
375 				++ifp->if_ierrors;
376 				return NULL;
377 			}
378 		}
379 
380 		ah = mtod(m, struct arc_header *);
381 	}
382 
383 	af = &ac->ac_fragtab[src];
384 	m1 = af->af_packet;
385 	s = "debug code error";
386 
387 	if (ah->arc_flag & 1) {
388 		/*
389 		 * first fragment. We always initialize, which is
390 		 * about the right thing to do, as we only want to
391 		 * accept one fragmented packet per src at a time.
392 		 */
393 		if (m1 != NULL)
394 			m_freem(m1);
395 
396 		af->af_packet = m;
397 		m1 = m;
398 		af->af_maxflag = ah->arc_flag;
399 		af->af_lastseen = 0;
400 		af->af_seqid = ah->arc_seqid;
401 
402 		return NULL;
403 		/* notreached */
404 	} else {
405 		/* check for unfragmented packet */
406 		if (ah->arc_flag == 0)
407 			return m;
408 
409 		/* do we have a first packet from that src? */
410 		if (m1 == NULL) {
411 			s = "no first frag";
412 			goto outofseq;
413 		}
414 
415 		ah1 = mtod(m1, struct arc_header *);
416 
417 		if (ah->arc_seqid != ah1->arc_seqid) {
418 			s = "seqid differs";
419 			goto outofseq;
420 		}
421 
422 		if (typ != ah1->arc_type) {
423 			s = "type differs";
424 			goto outofseq;
425 		}
426 
427 		if (dst != ah1->arc_dhost) {
428 			s = "dest host differs";
429 			goto outofseq;
430 		}
431 
432 		/* typ, seqid and dst are ok here. */
433 
434 		if (ah->arc_flag == af->af_lastseen) {
435 			m_freem(m);
436 			return NULL;
437 		}
438 
439 		if (ah->arc_flag == af->af_lastseen + 2) {
440 			/* ok, this is next fragment */
441 			af->af_lastseen = ah->arc_flag;
442 			m_adj(m, ARC_HDRNEWLEN);
443 
444 			/*
445 			 * m_cat might free the first mbuf (with pkthdr)
446 			 * in 2nd chain; therefore:
447 			 */
448 
449 			newflen = m->m_pkthdr.len;
450 
451 			m_cat(m1, m);
452 
453 			m1->m_pkthdr.len += newflen;
454 
455 			/* is it the last one? */
456 			if (af->af_lastseen > af->af_maxflag) {
457 				af->af_packet = NULL;
458 				return (m1);
459 			} else
460 				return NULL;
461 		}
462 		s = "other reason";
463 		/* if all else fails, it is out of sequence, too */
464 	}
465 outofseq:
466 	if (m1) {
467 		m_freem(m1);
468 		af->af_packet = NULL;
469 	}
470 
471 	if (m)
472 		m_freem(m);
473 
474 	log(LOG_INFO,"%s: got out of seq. packet: %s\n",
475 	    ifp->if_xname, s);
476 
477 	return NULL;
478 }
479 
480 /*
481  * return 1 if Packet Header Definition Standard, else 0.
482  * For now: old IP, old ARP aren't obviously. Lacking correct information,
483  * we guess that besides new IP and new ARP also IPX and APPLETALK are PHDS.
484  * (Apple and Novell corporations were involved, among others, in PHDS work).
485  * Easiest is to assume that everybody else uses that, too.
486  */
487 int
488 arc_isphds(uint8_t type)
489 {
490 	return (type != ARCTYPE_IP_OLD &&
491 		type != ARCTYPE_ARP_OLD &&
492 		type != ARCTYPE_DIAGNOSE);
493 }
494 
495 /*
496  * Process a received Arcnet packet;
497  * the packet is in the mbuf chain m with
498  * the ARCnet header.
499  */
500 static void
501 arc_input(struct ifnet *ifp, struct mbuf *m)
502 {
503 	pktqueue_t *pktq = NULL;
504 	struct arc_header *ah;
505 	struct ifqueue *inq;
506 	uint8_t atype;
507 	int isr = 0;
508 	int s;
509 
510 	if ((ifp->if_flags & IFF_UP) == 0) {
511 		m_freem(m);
512 		return;
513 	}
514 
515 	/* possibly defragment: */
516 	m = arc_defrag(ifp, m);
517 	if (m == NULL)
518 		return;
519 
520 	ah = mtod(m, struct arc_header *);
521 
522 	ifp->if_ibytes += m->m_pkthdr.len;
523 
524 	if (arcbroadcastaddr == ah->arc_dhost) {
525 		m->m_flags |= M_BCAST|M_MCAST;
526 		ifp->if_imcasts++;
527 	}
528 
529 	atype = ah->arc_type;
530 	switch (atype) {
531 #ifdef INET
532 	case ARCTYPE_IP:
533 		m_adj(m, ARC_HDRNEWLEN);
534 		pktq = ip_pktq;
535 		break;
536 
537 	case ARCTYPE_IP_OLD:
538 		m_adj(m, ARC_HDRLEN);
539 		pktq = ip_pktq;
540 		break;
541 
542 	case ARCTYPE_ARP:
543 		m_adj(m, ARC_HDRNEWLEN);
544 		isr = NETISR_ARP;
545 		inq = &arpintrq;
546 #ifdef ARCNET_ALLOW_BROKEN_ARP
547 		mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP);
548 #endif
549 		break;
550 
551 	case ARCTYPE_ARP_OLD:
552 		m_adj(m, ARC_HDRLEN);
553 		isr = NETISR_ARP;
554 		inq = &arpintrq;
555 #ifdef ARCNET_ALLOW_BROKEN_ARP
556 		mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP);
557 #endif
558 		break;
559 #endif
560 #ifdef INET6
561 	case ARCTYPE_INET6:
562 		m_adj(m, ARC_HDRNEWLEN);
563 		pktq = ip6_pktq;
564 		break;
565 #endif
566 	default:
567 		m_freem(m);
568 		return;
569 	}
570 
571 	s = splnet();
572 	if (__predict_true(pktq)) {
573 		if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
574 			m_freem(m);
575 		}
576 		splx(s);
577 		return;
578 	}
579 	if (IF_QFULL(inq)) {
580 		IF_DROP(inq);
581 		m_freem(m);
582 	} else {
583 		IF_ENQUEUE(inq, m);
584 		schednetisr(isr);
585 	}
586 	splx(s);
587 }
588 
589 /*
590  * Convert Arcnet address to printable (loggable) representation.
591  */
592 char *
593 arc_sprintf(uint8_t *ap)
594 {
595 	static char arcbuf[3];
596 	char *cp = arcbuf;
597 
598 	*cp++ = hexdigits[*ap >> 4];
599 	*cp++ = hexdigits[*ap++ & 0xf];
600 	*cp   = 0;
601 	return (arcbuf);
602 }
603 
604 /*
605  * Perform common duties while attaching to interface list
606  */
607 void
608 arc_ifattach(struct ifnet *ifp, uint8_t lla)
609 {
610 	struct arccom *ac;
611 
612 	ifp->if_type = IFT_ARCNET;
613 	ifp->if_addrlen = 1;
614 	ifp->if_hdrlen = ARC_HDRLEN;
615 	ifp->if_dlt = DLT_ARCNET;
616 	if (ifp->if_flags & IFF_BROADCAST)
617 		ifp->if_flags |= IFF_MULTICAST|IFF_ALLMULTI;
618 	if (ifp->if_flags & IFF_LINK0 && arc_ipmtu > ARC_PHDS_MAXMTU)
619 		log(LOG_ERR,
620 		    "%s: arc_ipmtu is %d, but must not exceed %d\n",
621 		    ifp->if_xname, arc_ipmtu, ARC_PHDS_MAXMTU);
622 
623 	ifp->if_output = arc_output;
624 	ifp->_if_input = arc_input;
625 	ac = (struct arccom *)ifp;
626 	ac->ac_seqid = (time_second) & 0xFFFF; /* try to make seqid unique */
627 	if (lla == 0) {
628 		/* XXX this message isn't entirely clear, to me -- cgd */
629 		log(LOG_ERR,"%s: link address 0 reserved for broadcasts.  Please change it and ifconfig %s down up\n",
630 		   ifp->if_xname, ifp->if_xname);
631 	}
632 	if_attach(ifp);
633 	if_set_sadl(ifp, &lla, sizeof(lla), true);
634 
635 	ifp->if_broadcastaddr = &arcbroadcastaddr;
636 
637 	bpf_attach(ifp, DLT_ARCNET, ARC_HDRLEN);
638 }
639