1 /* $NetBSD: if_arcsubr.c,v 1.87 2025/09/21 15:11:52 christos 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 1.87 2025/09/21 15:11:52 christos 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 rt_unhandled(__func__, ifp, dst); 187 senderr(EAFNOSUPPORT); 188 } 189 190 atype = htons(ARCTYPE_REVARP); 191 newencoding = 1; 192 break; 193 194 case ARPOP_REQUEST: 195 case ARPOP_REPLY: 196 default: 197 if (ifp->if_flags & IFF_LINK0) { 198 atype = htons(ARCTYPE_ARP); 199 newencoding = 1; 200 } else { 201 atype = htons(ARCTYPE_ARP_OLD); 202 newencoding = 0; 203 } 204 } 205 #ifdef ARCNET_ALLOW_BROKEN_ARP 206 /* 207 * XXX It's not clear per RFC826 if this is needed, but 208 * "assigned numbers" say this is wrong. 209 * However, e.g., AmiTCP 3.0Beta used it... we make this 210 * switchable for emergency cases. Not perfect, but... 211 */ 212 if (ifp->if_flags & IFF_LINK2) 213 arph->ar_pro = atype - 1; 214 #endif 215 break; 216 #endif 217 #ifdef INET6 218 case AF_INET6: 219 if (m->m_flags & M_MCAST) { 220 adst = 0; 221 } else { 222 error = nd6_resolve(ifp, rt, m, dst, &adst, 223 sizeof(adst)); 224 if (error != 0) 225 return error == EWOULDBLOCK ? 0 : error; 226 } 227 atype = htons(ARCTYPE_INET6); 228 newencoding = 1; 229 break; 230 #endif 231 232 case AF_UNSPEC: 233 cah = (const struct arc_header *)dst->sa_data; 234 adst = cah->arc_dhost; 235 atype = cah->arc_type; 236 break; 237 238 default: 239 rt_unhandled(__func__, ifp, dst); 240 senderr(EAFNOSUPPORT); 241 } 242 243 if (mcopy) 244 (void) looutput(ifp, mcopy, dst, rt); 245 246 /* 247 * Add local net header. If no space in first mbuf, 248 * allocate another. 249 * 250 * For ARCnet, this is just symbolic. The header changes 251 * form and position on its way into the hardware and out of 252 * the wire. At this point, it contains source, destination and 253 * packet type. 254 */ 255 if (newencoding) { 256 ++ac->ac_seqid; /* make the seqid unique */ 257 258 tfrags = (m->m_pkthdr.len + 503) / 504; 259 fsflag = 2 * tfrags - 3; 260 sflag = 0; 261 rsflag = fsflag; 262 263 while (sflag < fsflag) { 264 /* we CAN'T have short packets here */ 265 m1 = m_split(m, 504, M_DONTWAIT); 266 if (m1 == 0) 267 senderr(ENOBUFS); 268 269 M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT); 270 if (m == 0) 271 senderr(ENOBUFS); 272 ah = mtod(m, struct arc_header *); 273 ah->arc_type = atype; 274 ah->arc_dhost = adst; 275 ah->arc_shost = myself; 276 ah->arc_flag = rsflag; 277 ah->arc_seqid = ac->ac_seqid; 278 279 if ((error = ifq_enqueue(ifp, m)) != 0) 280 return (error); 281 282 m = m1; 283 sflag += 2; 284 rsflag = sflag; 285 } 286 m1 = NULL; 287 288 289 /* here we can have small, especially forbidden packets */ 290 291 if ((m->m_pkthdr.len >= 292 ARC_MIN_FORBID_LEN - ARC_HDRNEWLEN + 2) && 293 (m->m_pkthdr.len <= 294 ARC_MAX_FORBID_LEN - ARC_HDRNEWLEN + 2)) { 295 296 M_PREPEND(m, ARC_HDRNEWLEN_EXC, M_DONTWAIT); 297 if (m == 0) 298 senderr(ENOBUFS); 299 ah = mtod(m, struct arc_header *); 300 ah->arc_flag = 0xFF; 301 ah->arc_seqid = 0xFFFF; 302 ah->arc_type2 = atype; 303 ah->arc_flag2 = sflag; 304 ah->arc_seqid2 = ac->ac_seqid; 305 } else { 306 M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT); 307 if (m == 0) 308 senderr(ENOBUFS); 309 ah = mtod(m, struct arc_header *); 310 ah->arc_flag = sflag; 311 ah->arc_seqid = ac->ac_seqid; 312 } 313 314 ah->arc_dhost = adst; 315 ah->arc_shost = myself; 316 ah->arc_type = atype; 317 } else { 318 M_PREPEND(m, ARC_HDRLEN, M_DONTWAIT); 319 if (m == 0) 320 senderr(ENOBUFS); 321 ah = mtod(m, struct arc_header *); 322 ah->arc_type = atype; 323 ah->arc_dhost = adst; 324 ah->arc_shost = myself; 325 } 326 327 return ifq_enqueue(ifp, m); 328 329 bad: 330 m_freem(m1); 331 m_freem(m); 332 return (error); 333 } 334 335 /* 336 * Defragmenter. Returns mbuf if last packet found, else 337 * NULL. frees imcoming mbuf as necessary. 338 */ 339 340 static struct mbuf * 341 arc_defrag(struct ifnet *ifp, struct mbuf *m) 342 { 343 struct arc_header *ah, *ah1; 344 struct arccom *ac; 345 struct ac_frag *af; 346 struct mbuf *m1; 347 const char *s; 348 int newflen; 349 u_char src, dst, typ; 350 351 ac = (struct arccom *)ifp; 352 353 if (m->m_len < ARC_HDRNEWLEN) { 354 m = m_pullup(m, ARC_HDRNEWLEN); 355 if (m == NULL) { 356 if_statinc(ifp, if_ierrors); 357 return NULL; 358 } 359 } 360 361 ah = mtod(m, struct arc_header *); 362 typ = ah->arc_type; 363 364 if (!arc_isphds(typ)) 365 return m; 366 367 src = ah->arc_shost; 368 dst = ah->arc_dhost; 369 370 if (ah->arc_flag == 0xff) { 371 m_adj(m, 4); 372 373 if (m->m_len < ARC_HDRNEWLEN) { 374 m = m_pullup(m, ARC_HDRNEWLEN); 375 if (m == NULL) { 376 if_statinc(ifp, if_ierrors); 377 return NULL; 378 } 379 } 380 381 ah = mtod(m, struct arc_header *); 382 } 383 384 af = &ac->ac_fragtab[src]; 385 m1 = af->af_packet; 386 s = "debug code error"; 387 388 if (ah->arc_flag & 1) { 389 /* 390 * first fragment. We always initialize, which is 391 * about the right thing to do, as we only want to 392 * accept one fragmented packet per src at a time. 393 */ 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 m_freem(m); 472 473 log(LOG_INFO,"%s: got out of seq. packet: %s\n", 474 ifp->if_xname, s); 475 476 return NULL; 477 } 478 479 /* 480 * return 1 if Packet Header Definition Standard, else 0. 481 * For now: old IP, old ARP aren't obviously. Lacking correct information, 482 * we guess that besides new IP and new ARP also IPX and APPLETALK are PHDS. 483 * (Apple and Novell corporations were involved, among others, in PHDS work). 484 * Easiest is to assume that everybody else uses that, too. 485 */ 486 int 487 arc_isphds(uint8_t type) 488 { 489 return (type != ARCTYPE_IP_OLD && 490 type != ARCTYPE_ARP_OLD && 491 type != ARCTYPE_DIAGNOSE); 492 } 493 494 /* 495 * Process a received Arcnet packet; 496 * the packet is in the mbuf chain m with 497 * the ARCnet header. 498 */ 499 static void 500 arc_input(struct ifnet *ifp, struct mbuf *m) 501 { 502 pktqueue_t *pktq = NULL; 503 struct arc_header *ah; 504 uint8_t atype; 505 506 if ((ifp->if_flags & IFF_UP) == 0) { 507 m_freem(m); 508 return; 509 } 510 511 /* possibly defragment: */ 512 m = arc_defrag(ifp, m); 513 if (m == NULL) 514 return; 515 516 ah = mtod(m, struct arc_header *); 517 518 if_statadd(ifp, if_ibytes, m->m_pkthdr.len); 519 520 if (arcbroadcastaddr == ah->arc_dhost) { 521 m->m_flags |= M_BCAST|M_MCAST; 522 if_statinc(ifp, if_imcasts); 523 } 524 525 atype = ah->arc_type; 526 switch (atype) { 527 #ifdef INET 528 case ARCTYPE_IP: 529 m_adj(m, ARC_HDRNEWLEN); 530 pktq = ip_pktq; 531 break; 532 533 case ARCTYPE_IP_OLD: 534 m_adj(m, ARC_HDRLEN); 535 pktq = ip_pktq; 536 break; 537 538 case ARCTYPE_ARP: 539 m_adj(m, ARC_HDRNEWLEN); 540 pktq = arp_pktq; 541 #ifdef ARCNET_ALLOW_BROKEN_ARP 542 mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP); 543 #endif 544 break; 545 546 case ARCTYPE_ARP_OLD: 547 m_adj(m, ARC_HDRLEN); 548 pktq = arp_pktq; 549 #ifdef ARCNET_ALLOW_BROKEN_ARP 550 mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP); 551 #endif 552 break; 553 #endif 554 #ifdef INET6 555 case ARCTYPE_INET6: 556 m_adj(m, ARC_HDRNEWLEN); 557 pktq = ip6_pktq; 558 break; 559 #endif 560 default: 561 m_freem(m); 562 return; 563 } 564 565 KASSERT(pktq != NULL); 566 if (__predict_false(!pktq_enqueue(pktq, m, 0))) { 567 m_freem(m); 568 } 569 } 570 571 /* 572 * Convert Arcnet address to printable (loggable) representation. 573 */ 574 char * 575 arc_sprintf(uint8_t *ap) 576 { 577 static char arcbuf[3]; 578 char *cp = arcbuf; 579 580 *cp++ = hexdigits[*ap >> 4]; 581 *cp++ = hexdigits[*ap++ & 0xf]; 582 *cp = 0; 583 return (arcbuf); 584 } 585 586 /* 587 * Perform common duties while attaching to interface list 588 */ 589 int 590 arc_ifattach(struct ifnet *ifp, uint8_t lla) 591 { 592 struct arccom *ac; 593 594 ifp->if_type = IFT_ARCNET; 595 ifp->if_addrlen = 1; 596 ifp->if_hdrlen = ARC_HDRLEN; 597 ifp->if_dlt = DLT_ARCNET; 598 if (ifp->if_flags & IFF_BROADCAST) 599 ifp->if_flags |= IFF_MULTICAST|IFF_ALLMULTI; 600 if (ifp->if_flags & IFF_LINK0 && arc_ipmtu > ARC_PHDS_MAXMTU) 601 log(LOG_ERR, 602 "%s: arc_ipmtu is %d, but must not exceed %d\n", 603 ifp->if_xname, arc_ipmtu, ARC_PHDS_MAXMTU); 604 605 ifp->if_output = arc_output; 606 ifp->_if_input = arc_input; 607 ac = (struct arccom *)ifp; 608 ac->ac_seqid = (time_second) & 0xFFFF; /* try to make seqid unique */ 609 if (lla == 0) { 610 /* XXX this message isn't entirely clear, to me -- cgd */ 611 log(LOG_ERR,"%s: link address 0 reserved for broadcasts. Please change it and ifconfig %s down up\n", 612 ifp->if_xname, ifp->if_xname); 613 } 614 if_attach(ifp); 615 616 if_set_sadl(ifp, &lla, sizeof(lla), true); 617 618 ifp->if_broadcastaddr = &arcbroadcastaddr; 619 620 bpf_attach(ifp, DLT_ARCNET, ARC_HDRLEN); 621 622 return 0; 623 } 624
Indexes created Sun Sep 21 16:09:51 GMT 2025