FreeBSD/Linux Kernel Cross Reference
sys/net/if_arcsubr.c
1 /* $NetBSD: if_arcsubr.c,v 1.85 2022/09/03 02:47:59 thorpej 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 1.85 2022/09/03 02:47:59 thorpej 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/ioctl.h>
50 #include <sys/errno.h>
51 #include <sys/syslog.h>
52
53 #include <sys/cpu.h>
54
55 #include <net/if.h>
56 #include <net/route.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 #include <net/if_arc.h>
60 #include <net/if_arp.h>
61 #include <net/if_ether.h>
62
63 #include <net/bpf.h>
64
65 #ifdef INET
66 #include <netinet/in.h>
67 #include <netinet/in_var.h>
68 #include <netinet/if_inarp.h>
69 #endif
70
71 #ifdef INET6
72 #ifndef INET
73 #include <netinet/in.h>
74 #endif
75 #include <netinet6/in6_var.h>
76 #include <netinet6/nd6.h>
77 #endif
78
79 #define ARCNET_ALLOW_BROKEN_ARP
80
81 #ifndef ARC_IPMTU
82 #define ARC_IPMTU 1500
83 #endif
84
85 static struct mbuf *arc_defrag(struct ifnet *, struct mbuf *);
86
87 /*
88 * RC1201 requires us to have this configurable. We have it only per
89 * machine at the moment... there is no generic "set mtu" ioctl, AFAICS.
90 * Anyway, it is possible to binpatch this or set it per kernel config
91 * option.
92 */
93 #if ARC_IPMTU > 60480
94 ERROR: The arc_ipmtu is ARC_IPMTU, but must not exceed 60480.
95 #endif
96 int arc_ipmtu = ARC_IPMTU;
97 uint8_t arcbroadcastaddr = 0;
98
99 #define senderr(e) { error = (e); goto bad;}
100
101 static int arc_output(struct ifnet *, struct mbuf *,
102 const struct sockaddr *, const struct rtentry *);
103 static void arc_input(struct ifnet *, struct mbuf *);
104
105 /*
106 * ARCnet output routine.
107 * Encapsulate a packet of type family for the local net.
108 * Assumes that ifp is actually pointer to arccom structure.
109 */
110 static int
111 arc_output(struct ifnet *ifp, struct mbuf *m0, const struct sockaddr *dst,
112 const struct rtentry *rt)
113 {
114 struct mbuf *m, *m1, *mcopy;
115 struct arccom *ac;
116 const struct arc_header *cah;
117 struct arc_header *ah;
118 struct arphdr *arph;
119 int error, newencoding;
120 uint8_t atype, adst, myself;
121 int tfrags, sflag, fsflag, rsflag;
122
123 if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
124 return (ENETDOWN); /* m, m1 aren't initialized yet */
125
126 error = newencoding = 0;
127 ac = (struct arccom *)ifp;
128 m = m0;
129 mcopy = m1 = NULL;
130
131 myself = *CLLADDR(ifp->if_sadl);
132
133 /*
134 * if the queueing discipline needs packet classification,
135 * do it before prepending link headers.
136 */
137 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
138
139 switch (dst->sa_family) {
140 #ifdef INET
141 case AF_INET:
142
143 /*
144 * For now, use the simple IP addr -> ARCnet addr mapping
145 */
146 if (m->m_flags & (M_BCAST|M_MCAST))
147 adst = arcbroadcastaddr; /* ARCnet broadcast address */
148 else if (ifp->if_flags & IFF_NOARP)
149 adst = ntohl(satocsin(dst)->sin_addr.s_addr) & 0xFF;
150 else if ((error = arpresolve(ifp, rt, m, dst, &adst,
151 sizeof(adst))) != 0)
152 return error == EWOULDBLOCK ? 0 : error;
153
154 /* If broadcasting on a simplex interface, loopback a copy */
155 if ((m->m_flags & (M_BCAST|M_MCAST)) &&
156 (ifp->if_flags & IFF_SIMPLEX))
157 mcopy = m_copypacket(m, M_DONTWAIT);
158 if (ifp->if_flags & IFF_LINK0) {
159 atype = ARCTYPE_IP;
160 newencoding = 1;
161 } else {
162 atype = ARCTYPE_IP_OLD;
163 newencoding = 0;
164 }
165 break;
166
167 case AF_ARP:
168 arph = mtod(m, struct arphdr *);
169 if (m->m_flags & M_BCAST)
170 adst = arcbroadcastaddr;
171 else {
172 uint8_t *tha = ar_tha(arph);
173 if (tha == NULL) {
174 m_freem(m);
175 return 0;
176 }
177 adst = *tha;
178 }
179
180 arph->ar_hrd = htons(ARPHRD_ARCNET);
181
182 switch (ntohs(arph->ar_op)) {
183 case ARPOP_REVREQUEST:
184 case ARPOP_REVREPLY:
185 if (!(ifp->if_flags & IFF_LINK0)) {
186 printf("%s: can't handle af%d\n",
187 ifp->if_xname, dst->sa_family);
188 senderr(EAFNOSUPPORT);
189 }
190
191 atype = htons(ARCTYPE_REVARP);
192 newencoding = 1;
193 break;
194
195 case ARPOP_REQUEST:
196 case ARPOP_REPLY:
197 default:
198 if (ifp->if_flags & IFF_LINK0) {
199 atype = htons(ARCTYPE_ARP);
200 newencoding = 1;
201 } else {
202 atype = htons(ARCTYPE_ARP_OLD);
203 newencoding = 0;
204 }
205 }
206 #ifdef ARCNET_ALLOW_BROKEN_ARP
207 /*
208 * XXX It's not clear per RFC826 if this is needed, but
209 * "assigned numbers" say this is wrong.
210 * However, e.g., AmiTCP 3.0Beta used it... we make this
211 * switchable for emergency cases. Not perfect, but...
212 */
213 if (ifp->if_flags & IFF_LINK2)
214 arph->ar_pro = atype - 1;
215 #endif
216 break;
217 #endif
218 #ifdef INET6
219 case AF_INET6:
220 if (m->m_flags & M_MCAST) {
221 adst = 0;
222 } else {
223 error = nd6_resolve(ifp, rt, m, dst, &adst,
224 sizeof(adst));
225 if (error != 0)
226 return error == EWOULDBLOCK ? 0 : error;
227 }
228 atype = htons(ARCTYPE_INET6);
229 newencoding = 1;
230 break;
231 #endif
232
233 case AF_UNSPEC:
234 cah = (const struct arc_header *)dst->sa_data;
235 adst = cah->arc_dhost;
236 atype = cah->arc_type;
237 break;
238
239 default:
240 printf("%s: can't handle af%d\n", ifp->if_xname,
241 dst->sa_family);
242 senderr(EAFNOSUPPORT);
243 }
244
245 if (mcopy)
246 (void) looutput(ifp, mcopy, dst, rt);
247
248 /*
249 * Add local net header. If no space in first mbuf,
250 * allocate another.
251 *
252 * For ARCnet, this is just symbolic. The header changes
253 * form and position on its way into the hardware and out of
254 * the wire. At this point, it contains source, destination and
255 * packet type.
256 */
257 if (newencoding) {
258 ++ac->ac_seqid; /* make the seqid unique */
259
260 tfrags = (m->m_pkthdr.len + 503) / 504;
261 fsflag = 2 * tfrags - 3;
262 sflag = 0;
263 rsflag = fsflag;
264
265 while (sflag < fsflag) {
266 /* we CAN'T have short packets here */
267 m1 = m_split(m, 504, M_DONTWAIT);
268 if (m1 == 0)
269 senderr(ENOBUFS);
270
271 M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT);
272 if (m == 0)
273 senderr(ENOBUFS);
274 ah = mtod(m, struct arc_header *);
275 ah->arc_type = atype;
276 ah->arc_dhost = adst;
277 ah->arc_shost = myself;
278 ah->arc_flag = rsflag;
279 ah->arc_seqid = ac->ac_seqid;
280
281 if ((error = ifq_enqueue(ifp, m)) != 0)
282 return (error);
283
284 m = m1;
285 sflag += 2;
286 rsflag = sflag;
287 }
288 m1 = NULL;
289
290
291 /* here we can have small, especially forbidden packets */
292
293 if ((m->m_pkthdr.len >=
294 ARC_MIN_FORBID_LEN - ARC_HDRNEWLEN + 2) &&
295 (m->m_pkthdr.len <=
296 ARC_MAX_FORBID_LEN - ARC_HDRNEWLEN + 2)) {
297
298 M_PREPEND(m, ARC_HDRNEWLEN_EXC, M_DONTWAIT);
299 if (m == 0)
300 senderr(ENOBUFS);
301 ah = mtod(m, struct arc_header *);
302 ah->arc_flag = 0xFF;
303 ah->arc_seqid = 0xFFFF;
304 ah->arc_type2 = atype;
305 ah->arc_flag2 = sflag;
306 ah->arc_seqid2 = ac->ac_seqid;
307 } else {
308 M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT);
309 if (m == 0)
310 senderr(ENOBUFS);
311 ah = mtod(m, struct arc_header *);
312 ah->arc_flag = sflag;
313 ah->arc_seqid = ac->ac_seqid;
314 }
315
316 ah->arc_dhost = adst;
317 ah->arc_shost = myself;
318 ah->arc_type = atype;
319 } else {
320 M_PREPEND(m, ARC_HDRLEN, M_DONTWAIT);
321 if (m == 0)
322 senderr(ENOBUFS);
323 ah = mtod(m, struct arc_header *);
324 ah->arc_type = atype;
325 ah->arc_dhost = adst;
326 ah->arc_shost = myself;
327 }
328
329 return ifq_enqueue(ifp, m);
330
331 bad:
332 if (m1)
333 m_freem(m1);
334 if (m)
335 m_freem(m);
336 return (error);
337 }
338
339 /*
340 * Defragmenter. Returns mbuf if last packet found, else
341 * NULL. frees imcoming mbuf as necessary.
342 */
343
344 static struct mbuf *
345 arc_defrag(struct ifnet *ifp, struct mbuf *m)
346 {
347 struct arc_header *ah, *ah1;
348 struct arccom *ac;
349 struct ac_frag *af;
350 struct mbuf *m1;
351 const char *s;
352 int newflen;
353 u_char src, dst, typ;
354
355 ac = (struct arccom *)ifp;
356
357 if (m->m_len < ARC_HDRNEWLEN) {
358 m = m_pullup(m, ARC_HDRNEWLEN);
359 if (m == NULL) {
360 if_statinc(ifp, if_ierrors);
361 return NULL;
362 }
363 }
364
365 ah = mtod(m, struct arc_header *);
366 typ = ah->arc_type;
367
368 if (!arc_isphds(typ))
369 return m;
370
371 src = ah->arc_shost;
372 dst = ah->arc_dhost;
373
374 if (ah->arc_flag == 0xff) {
375 m_adj(m, 4);
376
377 if (m->m_len < ARC_HDRNEWLEN) {
378 m = m_pullup(m, ARC_HDRNEWLEN);
379 if (m == NULL) {
380 if_statinc(ifp, if_ierrors);
381 return NULL;
382 }
383 }
384
385 ah = mtod(m, struct arc_header *);
386 }
387
388 af = &ac->ac_fragtab[src];
389 m1 = af->af_packet;
390 s = "debug code error";
391
392 if (ah->arc_flag & 1) {
393 /*
394 * first fragment. We always initialize, which is
395 * about the right thing to do, as we only want to
396 * accept one fragmented packet per src at a time.
397 */
398 if (m1 != NULL)
399 m_freem(m1);
400
401 af->af_packet = m;
402 m1 = m;
403 af->af_maxflag = ah->arc_flag;
404 af->af_lastseen = 0;
405 af->af_seqid = ah->arc_seqid;
406
407 return NULL;
408 /* notreached */
409 } else {
410 /* check for unfragmented packet */
411 if (ah->arc_flag == 0)
412 return m;
413
414 /* do we have a first packet from that src? */
415 if (m1 == NULL) {
416 s = "no first frag";
417 goto outofseq;
418 }
419
420 ah1 = mtod(m1, struct arc_header *);
421
422 if (ah->arc_seqid != ah1->arc_seqid) {
423 s = "seqid differs";
424 goto outofseq;
425 }
426
427 if (typ != ah1->arc_type) {
428 s = "type differs";
429 goto outofseq;
430 }
431
432 if (dst != ah1->arc_dhost) {
433 s = "dest host differs";
434 goto outofseq;
435 }
436
437 /* typ, seqid and dst are ok here. */
438
439 if (ah->arc_flag == af->af_lastseen) {
440 m_freem(m);
441 return NULL;
442 }
443
444 if (ah->arc_flag == af->af_lastseen + 2) {
445 /* ok, this is next fragment */
446 af->af_lastseen = ah->arc_flag;
447 m_adj(m, ARC_HDRNEWLEN);
448
449 /*
450 * m_cat might free the first mbuf (with pkthdr)
451 * in 2nd chain; therefore:
452 */
453
454 newflen = m->m_pkthdr.len;
455
456 m_cat(m1, m);
457
458 m1->m_pkthdr.len += newflen;
459
460 /* is it the last one? */
461 if (af->af_lastseen > af->af_maxflag) {
462 af->af_packet = NULL;
463 return (m1);
464 } else
465 return NULL;
466 }
467 s = "other reason";
468 /* if all else fails, it is out of sequence, too */
469 }
470 outofseq:
471 if (m1) {
472 m_freem(m1);
473 af->af_packet = NULL;
474 }
475
476 if (m)
477 m_freem(m);
478
479 log(LOG_INFO,"%s: got out of seq. packet: %s\n",
480 ifp->if_xname, s);
481
482 return NULL;
483 }
484
485 /*
486 * return 1 if Packet Header Definition Standard, else 0.
487 * For now: old IP, old ARP aren't obviously. Lacking correct information,
488 * we guess that besides new IP and new ARP also IPX and APPLETALK are PHDS.
489 * (Apple and Novell corporations were involved, among others, in PHDS work).
490 * Easiest is to assume that everybody else uses that, too.
491 */
492 int
493 arc_isphds(uint8_t type)
494 {
495 return (type != ARCTYPE_IP_OLD &&
496 type != ARCTYPE_ARP_OLD &&
497 type != ARCTYPE_DIAGNOSE);
498 }
499
500 /*
501 * Process a received Arcnet packet;
502 * the packet is in the mbuf chain m with
503 * the ARCnet header.
504 */
505 static void
506 arc_input(struct ifnet *ifp, struct mbuf *m)
507 {
508 pktqueue_t *pktq = NULL;
509 struct arc_header *ah;
510 uint8_t atype;
511
512 if ((ifp->if_flags & IFF_UP) == 0) {
513 m_freem(m);
514 return;
515 }
516
517 /* possibly defragment: */
518 m = arc_defrag(ifp, m);
519 if (m == NULL)
520 return;
521
522 ah = mtod(m, struct arc_header *);
523
524 if_statadd(ifp, if_ibytes, m->m_pkthdr.len);
525
526 if (arcbroadcastaddr == ah->arc_dhost) {
527 m->m_flags |= M_BCAST|M_MCAST;
528 if_statinc(ifp, if_imcasts);
529 }
530
531 atype = ah->arc_type;
532 switch (atype) {
533 #ifdef INET
534 case ARCTYPE_IP:
535 m_adj(m, ARC_HDRNEWLEN);
536 pktq = ip_pktq;
537 break;
538
539 case ARCTYPE_IP_OLD:
540 m_adj(m, ARC_HDRLEN);
541 pktq = ip_pktq;
542 break;
543
544 case ARCTYPE_ARP:
545 m_adj(m, ARC_HDRNEWLEN);
546 pktq = arp_pktq;
547 #ifdef ARCNET_ALLOW_BROKEN_ARP
548 mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP);
549 #endif
550 break;
551
552 case ARCTYPE_ARP_OLD:
553 m_adj(m, ARC_HDRLEN);
554 pktq = arp_pktq;
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 KASSERT(pktq != NULL);
572 if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
573 m_freem(m);
574 }
575 }
576
577 /*
578 * Convert Arcnet address to printable (loggable) representation.
579 */
580 char *
581 arc_sprintf(uint8_t *ap)
582 {
583 static char arcbuf[3];
584 char *cp = arcbuf;
585
586 *cp++ = hexdigits[*ap >> 4];
587 *cp++ = hexdigits[*ap++ & 0xf];
588 *cp = 0;
589 return (arcbuf);
590 }
591
592 /*
593 * Perform common duties while attaching to interface list
594 */
595 int
596 arc_ifattach(struct ifnet *ifp, uint8_t lla)
597 {
598 struct arccom *ac;
599
600 ifp->if_type = IFT_ARCNET;
601 ifp->if_addrlen = 1;
602 ifp->if_hdrlen = ARC_HDRLEN;
603 ifp->if_dlt = DLT_ARCNET;
604 if (ifp->if_flags & IFF_BROADCAST)
605 ifp->if_flags |= IFF_MULTICAST|IFF_ALLMULTI;
606 if (ifp->if_flags & IFF_LINK0 && arc_ipmtu > ARC_PHDS_MAXMTU)
607 log(LOG_ERR,
608 "%s: arc_ipmtu is %d, but must not exceed %d\n",
609 ifp->if_xname, arc_ipmtu, ARC_PHDS_MAXMTU);
610
611 ifp->if_output = arc_output;
612 ifp->_if_input = arc_input;
613 ac = (struct arccom *)ifp;
614 ac->ac_seqid = (time_second) & 0xFFFF; /* try to make seqid unique */
615 if (lla == 0) {
616 /* XXX this message isn't entirely clear, to me -- cgd */
617 log(LOG_ERR,"%s: link address 0 reserved for broadcasts. Please change it and ifconfig %s down up\n",
618 ifp->if_xname, ifp->if_xname);
619 }
620 if_attach(ifp);
621
622 if_set_sadl(ifp, &lla, sizeof(lla), true);
623
624 ifp->if_broadcastaddr = &arcbroadcastaddr;
625
626 bpf_attach(ifp, DLT_ARCNET, ARC_HDRLEN);
627
628 return 0;
629 }
Cache object: 82076bd108f04bddcc8552a38eba43b0
|