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if_arcsubr.c revision 1.85.8.1
      1 /*	$NetBSD: if_arcsubr.c,v 1.85.8.1 2023/11/15 02:08:34 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 1.85.8.1 2023/11/15 02:08:34 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 = if_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 if_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 }
    630