Home | History | Annotate | Line # | Download | only in net
if_arcsubr.c revision 1.39
      1 /*	$NetBSD: if_arcsubr.c,v 1.39 2002/03/05 04:12:59 itojun 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. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  * from: NetBSD: if_ethersubr.c,v 1.9 1994/06/29 06:36:11 cgd Exp
     37  *       @(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
     38  *
     39  */
     40 
     41 #include <sys/cdefs.h>
     42 __KERNEL_RCSID(0, "$NetBSD: if_arcsubr.c,v 1.39 2002/03/05 04:12:59 itojun Exp $");
     43 
     44 #include "opt_inet.h"
     45 
     46 #include "bpfilter.h"
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/kernel.h>
     51 #include <sys/malloc.h>
     52 #include <sys/mbuf.h>
     53 #include <sys/protosw.h>
     54 #include <sys/socket.h>
     55 #include <sys/ioctl.h>
     56 #include <sys/errno.h>
     57 #include <sys/syslog.h>
     58 
     59 #include <machine/cpu.h>
     60 
     61 #include <net/if.h>
     62 #include <net/netisr.h>
     63 #include <net/route.h>
     64 #include <net/if_dl.h>
     65 #include <net/if_types.h>
     66 #include <net/if_arc.h>
     67 #include <net/if_arp.h>
     68 #include <net/if_ether.h>
     69 
     70 #if NBPFILTER > 0
     71 #include <net/bpf.h>
     72 #endif
     73 
     74 #ifdef INET
     75 #include <netinet/in.h>
     76 #include <netinet/in_var.h>
     77 #include <netinet/if_inarp.h>
     78 #endif
     79 
     80 #ifdef INET6
     81 #ifndef INET
     82 #include <netinet/in.h>
     83 #endif
     84 #include <netinet6/in6_var.h>
     85 #include <netinet6/nd6.h>
     86 #endif
     87 
     88 #define ARCNET_ALLOW_BROKEN_ARP
     89 
     90 #ifndef ARC_IPMTU
     91 #define ARC_IPMTU	1500
     92 #endif
     93 
     94 static struct mbuf *arc_defrag __P((struct ifnet *, struct mbuf *));
     95 
     96 /*
     97  * RC1201 requires us to have this configurable. We have it only per
     98  * machine at the moment... there is no generic "set mtu" ioctl, AFAICS.
     99  * Anyway, it is possible to binpatch this or set it per kernel config
    100  * option.
    101  */
    102 #if ARC_IPMTU > 60480
    103 ERROR: The arc_ipmtu is ARC_IPMTU, but must not exceed 60480.
    104 #endif
    105 int arc_ipmtu = ARC_IPMTU;
    106 u_int8_t  arcbroadcastaddr = 0;
    107 
    108 #define senderr(e) { error = (e); goto bad;}
    109 #define SIN(s) ((struct sockaddr_in *)s)
    110 
    111 static	int arc_output __P((struct ifnet *, struct mbuf *,
    112 	    struct sockaddr *, struct rtentry *));
    113 static	void arc_input __P((struct ifnet *, struct mbuf *));
    114 
    115 /*
    116  * ARCnet output routine.
    117  * Encapsulate a packet of type family for the local net.
    118  * Assumes that ifp is actually pointer to arccom structure.
    119  */
    120 static int
    121 arc_output(ifp, m0, dst, rt0)
    122 	struct ifnet *ifp;
    123 	struct mbuf *m0;
    124 	struct sockaddr *dst;
    125 	struct rtentry *rt0;
    126 {
    127 	struct mbuf		*m, *m1, *mcopy;
    128 	struct rtentry		*rt;
    129 	struct arccom		*ac;
    130 	struct arc_header	*ah;
    131 	struct arphdr		*arph;
    132 	int			s, error, newencoding, len;
    133 	u_int8_t		atype, adst, myself;
    134 	int			tfrags, sflag, fsflag, rsflag;
    135 	ALTQ_DECL(struct altq_pktattr pktattr;)
    136 
    137 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
    138 		return(ENETDOWN); /* m, m1 aren't initialized yet */
    139 
    140 	error = newencoding = 0;
    141 	ac = (struct arccom *)ifp;
    142 	m = m0;
    143 	mcopy = m1 = NULL;
    144 
    145 	myself = *LLADDR(ifp->if_sadl);
    146 
    147 	if ((rt = rt0)) {
    148 		if ((rt->rt_flags & RTF_UP) == 0) {
    149 			if ((rt0 = rt = rtalloc1(dst, 1)))
    150 				rt->rt_refcnt--;
    151 			else
    152 				senderr(EHOSTUNREACH);
    153 		}
    154 		if (rt->rt_flags & RTF_GATEWAY) {
    155 			if (rt->rt_gwroute == 0)
    156 				goto lookup;
    157 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
    158 				rtfree(rt); rt = rt0;
    159 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
    160 				if ((rt = rt->rt_gwroute) == 0)
    161 					senderr(EHOSTUNREACH);
    162 			}
    163 		}
    164 		if (rt->rt_flags & RTF_REJECT)
    165 			if (rt->rt_rmx.rmx_expire == 0 ||
    166 			    time.tv_sec < rt->rt_rmx.rmx_expire)
    167 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
    168 	}
    169 
    170 	/*
    171 	 * if the queueing discipline needs packet classification,
    172 	 * do it before prepending link headers.
    173 	 */
    174 	IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
    175 
    176 	switch (dst->sa_family) {
    177 #ifdef INET
    178 	case AF_INET:
    179 
    180 		/*
    181 		 * For now, use the simple IP addr -> ARCnet addr mapping
    182 		 */
    183 		if (m->m_flags & (M_BCAST|M_MCAST))
    184 			adst = arcbroadcastaddr; /* ARCnet broadcast address */
    185 		else if (ifp->if_flags & IFF_NOARP)
    186 			adst = ntohl(SIN(dst)->sin_addr.s_addr) & 0xFF;
    187 		else if (!arpresolve(ifp, rt, m, dst, &adst))
    188 			return 0;	/* not resolved yet */
    189 
    190 		/* If broadcasting on a simplex interface, loopback a copy */
    191 		if ((m->m_flags & (M_BCAST|M_MCAST)) &&
    192 		    (ifp->if_flags & IFF_SIMPLEX))
    193 			mcopy = m_copy(m, 0, (int)M_COPYALL);
    194 		if (ifp->if_flags & IFF_LINK0) {
    195 			atype = ARCTYPE_IP;
    196 			newencoding = 1;
    197 		} else {
    198 			atype = ARCTYPE_IP_OLD;
    199 			newencoding = 0;
    200 		}
    201 		break;
    202 
    203 	case AF_ARP:
    204 		arph = mtod(m, struct arphdr *);
    205 		if (m->m_flags & M_BCAST)
    206 			adst = arcbroadcastaddr;
    207 		else
    208 			adst = *ar_tha(arph);
    209 
    210 		arph->ar_hrd = htons(ARPHRD_ARCNET);
    211 
    212 		switch(ntohs(arph->ar_op)) {
    213 
    214 		case ARPOP_REVREQUEST:
    215 		case ARPOP_REVREPLY:
    216 			if (!(ifp->if_flags & IFF_LINK0)) {
    217 				printf("%s: can't handle af%d\n",
    218 				    ifp->if_xname, dst->sa_family);
    219 				senderr(EAFNOSUPPORT);
    220 			}
    221 
    222 			atype = htons(ARCTYPE_REVARP);
    223 			newencoding = 1;
    224 			break;
    225 
    226 		case ARPOP_REQUEST:
    227 		case ARPOP_REPLY:
    228 		default:
    229 			if (ifp->if_flags & IFF_LINK0) {
    230 				atype = htons(ARCTYPE_ARP);
    231 				newencoding = 1;
    232 			} else {
    233 				atype = htons(ARCTYPE_ARP_OLD);
    234 				newencoding = 0;
    235 			}
    236 		}
    237 #ifdef ARCNET_ALLOW_BROKEN_ARP
    238 		/*
    239 		 * XXX It's not clear per RFC826 if this is needed, but
    240 		 * "assigned numbers" say this is wrong.
    241 		 * However, e.g., AmiTCP 3.0Beta used it... we make this
    242 		 * switchable for emergency cases. Not perfect, but...
    243 		 */
    244 		if (ifp->if_flags & IFF_LINK2)
    245 			arph->ar_pro = atype - 1;
    246 #endif
    247 		break;
    248 #endif
    249 #ifdef INET6
    250 	case AF_INET6:
    251 		if (!nd6_storelladdr(ifp, rt, m, dst, (u_char *)&adst))
    252 			return(0); /* it must be impossible, but... */
    253 		atype = htons(ARCTYPE_INET6);
    254 		newencoding = 1;
    255 		break;
    256 #endif
    257 
    258 	case AF_UNSPEC:
    259 		ah = (struct arc_header *)dst->sa_data;
    260  		adst = ah->arc_dhost;
    261 		atype = ah->arc_type;
    262 		break;
    263 
    264 	default:
    265 		printf("%s: can't handle af%d\n", ifp->if_xname,
    266 		    dst->sa_family);
    267 		senderr(EAFNOSUPPORT);
    268 	}
    269 
    270 	if (mcopy)
    271 		(void) looutput(ifp, mcopy, dst, rt);
    272 
    273 	/*
    274 	 * Add local net header.  If no space in first mbuf,
    275 	 * allocate another.
    276 	 *
    277 	 * For ARCnet, this is just symbolic. The header changes
    278 	 * form and position on its way into the hardware and out of
    279 	 * the wire.  At this point, it contains source, destination and
    280 	 * packet type.
    281 	 */
    282 	if (newencoding) {
    283 		++ac->ac_seqid; /* make the seqid unique */
    284 
    285 		tfrags = (m->m_pkthdr.len + 503) / 504;
    286 		fsflag = 2 * tfrags - 3;
    287 		sflag = 0;
    288 		rsflag = fsflag;
    289 
    290 		while (sflag < fsflag) {
    291 			/* we CAN'T have short packets here */
    292 			m1 = m_split(m, 504, M_DONTWAIT);
    293 			if (m1 == 0)
    294 				senderr(ENOBUFS);
    295 
    296 			M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT);
    297 			if (m == 0)
    298 				senderr(ENOBUFS);
    299 			ah = mtod(m, struct arc_header *);
    300 			ah->arc_type = atype;
    301 			ah->arc_dhost = adst;
    302 			ah->arc_shost = myself;
    303 			ah->arc_flag = rsflag;
    304 			ah->arc_seqid = ac->ac_seqid;
    305 
    306 			len = m->m_pkthdr.len;
    307 			s = splnet();
    308 			/*
    309 			 * Queue message on interface, and start output if
    310 			 * interface not yet active.
    311 			 */
    312 			IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
    313 			if (error) {
    314 				/* mbuf is already freed */
    315 				splx(s);
    316 				return (error);
    317 			}
    318 			ifp->if_obytes += len;
    319 			if ((ifp->if_flags & IFF_OACTIVE) == 0)
    320 				(*ifp->if_start)(ifp);
    321 			splx(s);
    322 
    323 			m = m1;
    324 			sflag += 2;
    325 			rsflag = sflag;
    326 		}
    327 		m1 = NULL;
    328 
    329 
    330 		/* here we can have small, especially forbidden packets */
    331 
    332 		if ((m->m_pkthdr.len >=
    333 		    ARC_MIN_FORBID_LEN - ARC_HDRNEWLEN + 2) &&
    334 		    (m->m_pkthdr.len <=
    335 		    ARC_MAX_FORBID_LEN - ARC_HDRNEWLEN + 2)) {
    336 
    337 			M_PREPEND(m, ARC_HDRNEWLEN_EXC, M_DONTWAIT);
    338 			if (m == 0)
    339 				senderr(ENOBUFS);
    340 			ah = mtod(m, struct arc_header *);
    341 			ah->arc_flag = 0xFF;
    342 			ah->arc_seqid = 0xFFFF;
    343 			ah->arc_type2 = atype;
    344 			ah->arc_flag2 = sflag;
    345 			ah->arc_seqid2 = ac->ac_seqid;
    346 		} else {
    347 			M_PREPEND(m, ARC_HDRNEWLEN, M_DONTWAIT);
    348 			if (m == 0)
    349 				senderr(ENOBUFS);
    350 			ah = mtod(m, struct arc_header *);
    351 			ah->arc_flag = sflag;
    352 			ah->arc_seqid = ac->ac_seqid;
    353 		}
    354 
    355 		ah->arc_dhost = adst;
    356 		ah->arc_shost = myself;
    357 		ah->arc_type = atype;
    358 	} else {
    359 		M_PREPEND(m, ARC_HDRLEN, M_DONTWAIT);
    360 		if (m == 0)
    361 			senderr(ENOBUFS);
    362 		ah = mtod(m, struct arc_header *);
    363 		ah->arc_type = atype;
    364 		ah->arc_dhost = adst;
    365 		ah->arc_shost = myself;
    366 	}
    367 
    368 	len = m->m_pkthdr.len;
    369 	s = splnet();
    370 	/*
    371 	 * Queue message on interface, and start output if interface
    372 	 * not yet active.
    373 	 */
    374 	IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
    375 	if (error) {
    376 		/* mbuf is already freed */
    377 		splx(s);
    378 		return (error);
    379 	}
    380 	ifp->if_obytes += len;
    381 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
    382 		(*ifp->if_start)(ifp);
    383 	splx(s);
    384 
    385 	return (error);
    386 
    387 bad:
    388 	if (m1)
    389 		m_freem(m1);
    390 	if (m)
    391 		m_freem(m);
    392 	return (error);
    393 }
    394 
    395 /*
    396  * Defragmenter. Returns mbuf if last packet found, else
    397  * NULL. frees imcoming mbuf as necessary.
    398  */
    399 
    400 __inline struct mbuf *
    401 arc_defrag(ifp, m)
    402 	struct ifnet *ifp;
    403 	struct mbuf *m;
    404 {
    405 	struct arc_header *ah, *ah1;
    406 	struct arccom *ac;
    407 	struct ac_frag *af;
    408 	struct mbuf *m1;
    409 	char *s;
    410 	int newflen;
    411 	u_char src,dst,typ;
    412 
    413 	ac = (struct arccom *)ifp;
    414 
    415 	if (m->m_len < ARC_HDRNEWLEN) {
    416 		m = m_pullup(m, ARC_HDRNEWLEN);
    417 		if (m == NULL) {
    418 			++ifp->if_ierrors;
    419 			return NULL;
    420 		}
    421 	}
    422 
    423 	ah = mtod(m, struct arc_header *);
    424 	typ = ah->arc_type;
    425 
    426 	if (!arc_isphds(typ))
    427 		return m;
    428 
    429 	src = ah->arc_shost;
    430 	dst = ah->arc_dhost;
    431 
    432 	if (ah->arc_flag == 0xff) {
    433 		m_adj(m, 4);
    434 
    435 		if (m->m_len < ARC_HDRNEWLEN) {
    436 			m = m_pullup(m, ARC_HDRNEWLEN);
    437 			if (m == NULL) {
    438 				++ifp->if_ierrors;
    439 				return NULL;
    440 			}
    441 		}
    442 
    443 		ah = mtod(m, struct arc_header *);
    444 	}
    445 
    446 	af = &ac->ac_fragtab[src];
    447 	m1 = af->af_packet;
    448 	s = "debug code error";
    449 
    450 	if (ah->arc_flag & 1) {
    451 		/*
    452 		 * first fragment. We always initialize, which is
    453 		 * about the right thing to do, as we only want to
    454 		 * accept one fragmented packet per src at a time.
    455 		 */
    456 		if (m1 != NULL)
    457 			m_freem(m1);
    458 
    459 		af->af_packet = m;
    460 		m1 = m;
    461 		af->af_maxflag = ah->arc_flag;
    462 		af->af_lastseen = 0;
    463 		af->af_seqid = ah->arc_seqid;
    464 
    465 		return NULL;
    466 		/* notreached */
    467 	} else {
    468 		/* check for unfragmented packet */
    469 		if (ah->arc_flag == 0)
    470 			return m;
    471 
    472 		/* do we have a first packet from that src? */
    473 		if (m1 == NULL) {
    474 			s = "no first frag";
    475 			goto outofseq;
    476 		}
    477 
    478 		ah1 = mtod(m1, struct arc_header *);
    479 
    480 		if (ah->arc_seqid != ah1->arc_seqid) {
    481 			s = "seqid differs";
    482 			goto outofseq;
    483 		}
    484 
    485 		if (typ != ah1->arc_type) {
    486 			s = "type differs";
    487 			goto outofseq;
    488 		}
    489 
    490 		if (dst != ah1->arc_dhost) {
    491 			s = "dest host differs";
    492 			goto outofseq;
    493 		}
    494 
    495 		/* typ, seqid and dst are ok here. */
    496 
    497 		if (ah->arc_flag == af->af_lastseen) {
    498 			m_freem(m);
    499 			return NULL;
    500 		}
    501 
    502 		if (ah->arc_flag == af->af_lastseen + 2) {
    503 			/* ok, this is next fragment */
    504 			af->af_lastseen = ah->arc_flag;
    505 			m_adj(m,ARC_HDRNEWLEN);
    506 
    507 			/*
    508 			 * m_cat might free the first mbuf (with pkthdr)
    509 			 * in 2nd chain; therefore:
    510 			 */
    511 
    512 			newflen = m->m_pkthdr.len;
    513 
    514 			m_cat(m1,m);
    515 
    516 			m1->m_pkthdr.len += newflen;
    517 
    518 			/* is it the last one? */
    519 			if (af->af_lastseen > af->af_maxflag) {
    520 				af->af_packet = NULL;
    521 				return(m1);
    522 			} else
    523 				return NULL;
    524 		}
    525 		s = "other reason";
    526 		/* if all else fails, it is out of sequence, too */
    527 	}
    528 outofseq:
    529 	if (m1) {
    530 		m_freem(m1);
    531 		af->af_packet = NULL;
    532 	}
    533 
    534 	if (m)
    535 		m_freem(m);
    536 
    537 	log(LOG_INFO,"%s: got out of seq. packet: %s\n",
    538 	    ifp->if_xname, s);
    539 
    540 	return NULL;
    541 }
    542 
    543 /*
    544  * return 1 if Packet Header Definition Standard, else 0.
    545  * For now: old IP, old ARP aren't obviously. Lacking correct information,
    546  * we guess that besides new IP and new ARP also IPX and APPLETALK are PHDS.
    547  * (Apple and Novell corporations were involved, among others, in PHDS work).
    548  * Easiest is to assume that everybody else uses that, too.
    549  */
    550 int
    551 arc_isphds(type)
    552 	u_int8_t type;
    553 {
    554 	return (type != ARCTYPE_IP_OLD &&
    555 		type != ARCTYPE_ARP_OLD &&
    556 		type != ARCTYPE_DIAGNOSE);
    557 }
    558 
    559 /*
    560  * Process a received Arcnet packet;
    561  * the packet is in the mbuf chain m with
    562  * the ARCnet header.
    563  */
    564 static void
    565 arc_input(ifp, m)
    566 	struct ifnet *ifp;
    567 	struct mbuf *m;
    568 {
    569 	struct arc_header *ah;
    570 	struct ifqueue *inq;
    571 	u_int8_t atype;
    572 	int s;
    573 	struct arphdr *arph;
    574 
    575 	if ((ifp->if_flags & IFF_UP) == 0) {
    576 		m_freem(m);
    577 		return;
    578 	}
    579 
    580 	/* possibly defragment: */
    581 	m = arc_defrag(ifp, m);
    582 	if (m == NULL)
    583 		return;
    584 
    585 	ah = mtod(m, struct arc_header *);
    586 
    587 	ifp->if_ibytes += m->m_pkthdr.len;
    588 
    589 	if (arcbroadcastaddr == ah->arc_dhost) {
    590 		m->m_flags |= M_BCAST|M_MCAST;
    591 		ifp->if_imcasts++;
    592 	}
    593 
    594 	atype = ah->arc_type;
    595 	switch (atype) {
    596 #ifdef INET
    597 	case ARCTYPE_IP:
    598 		m_adj(m, ARC_HDRNEWLEN);
    599 		schednetisr(NETISR_IP);
    600 		inq = &ipintrq;
    601 		break;
    602 
    603 	case ARCTYPE_IP_OLD:
    604 		m_adj(m, ARC_HDRLEN);
    605 		schednetisr(NETISR_IP);
    606 		inq = &ipintrq;
    607 		break;
    608 
    609 	case ARCTYPE_ARP:
    610 		m_adj(m, ARC_HDRNEWLEN);
    611 		schednetisr(NETISR_ARP);
    612 		inq = &arpintrq;
    613 #ifdef ARCNET_ALLOW_BROKEN_ARP
    614 		mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP);
    615 #endif
    616 		break;
    617 
    618 	case ARCTYPE_ARP_OLD:
    619 		m_adj(m, ARC_HDRLEN);
    620 		schednetisr(NETISR_ARP);
    621 		inq = &arpintrq;
    622 		arph = mtod(m, struct arphdr *);
    623 #ifdef ARCNET_ALLOW_BROKEN_ARP
    624 		mtod(m, struct arphdr *)->ar_pro = htons(ETHERTYPE_IP);
    625 #endif
    626 		break;
    627 #endif
    628 #ifdef INET6
    629 	case ARCTYPE_INET6:
    630 		m_adj(m, ARC_HDRNEWLEN);
    631 		schednetisr(NETISR_IPV6);
    632 		inq = &ip6intrq;
    633 		break;
    634 #endif
    635 	default:
    636 		m_freem(m);
    637 		return;
    638 	}
    639 
    640 	s = splnet();
    641 	if (IF_QFULL(inq)) {
    642 		IF_DROP(inq);
    643 		m_freem(m);
    644 	} else
    645 		IF_ENQUEUE(inq, m);
    646 	splx(s);
    647 }
    648 
    649 /*
    650  * Convert Arcnet address to printable (loggable) representation.
    651  */
    652 static char digits[] = "0123456789abcdef";
    653 char *
    654 arc_sprintf(ap)
    655 	u_int8_t *ap;
    656 {
    657 	static char arcbuf[3];
    658 	char *cp = arcbuf;
    659 
    660 	*cp++ = digits[*ap >> 4];
    661 	*cp++ = digits[*ap++ & 0xf];
    662 	*cp   = 0;
    663 	return (arcbuf);
    664 }
    665 
    666 /*
    667  * Register (new) link level address.
    668  */
    669 void
    670 arc_storelladdr(ifp, lla)
    671 	struct ifnet *ifp;
    672 	u_int8_t lla;
    673 {
    674 
    675 	*(LLADDR(ifp->if_sadl)) = lla;
    676 	ifp->if_mtu = ARC_PHDS_MAXMTU;
    677 }
    678 
    679 /*
    680  * Perform common duties while attaching to interface list
    681  */
    682 void
    683 arc_ifattach(ifp, lla)
    684 	struct ifnet *ifp;
    685 	u_int8_t lla;
    686 {
    687 	struct arccom *ac;
    688 
    689 	ifp->if_type = IFT_ARCNET;
    690 	ifp->if_addrlen = 1;
    691 	ifp->if_hdrlen = ARC_HDRLEN;
    692 	ifp->if_dlt = DLT_ARCNET;
    693 	if (ifp->if_flags & IFF_BROADCAST)
    694 		ifp->if_flags |= IFF_MULTICAST|IFF_ALLMULTI;
    695 	if (ifp->if_flags & IFF_LINK0 && arc_ipmtu > ARC_PHDS_MAXMTU)
    696 		log(LOG_ERR,
    697 		    "%s: arc_ipmtu is %d, but must not exceed %d",
    698 		    ifp->if_xname, arc_ipmtu, ARC_PHDS_MAXMTU);
    699 
    700 	ifp->if_output = arc_output;
    701 	ifp->if_input = arc_input;
    702 	ac = (struct arccom *)ifp;
    703 	ac->ac_seqid = (time.tv_sec) & 0xFFFF; /* try to make seqid unique */
    704 	if (lla == 0) {
    705 		/* XXX this message isn't entirely clear, to me -- cgd */
    706 		log(LOG_ERR,"%s: link address 0 reserved for broadcasts.  Please change it and ifconfig %s down up\n",
    707 		   ifp->if_xname, ifp->if_xname);
    708 	}
    709 	if_attach(ifp);
    710 	if_alloc_sadl(ifp);
    711 	arc_storelladdr(ifp, lla);
    712 
    713 	ifp->if_broadcastaddr = &arcbroadcastaddr;
    714 
    715 #if NBPFILTER > 0
    716 	bpfattach(ifp, DLT_ARCNET, ARC_HDRLEN);
    717 #endif
    718 }
    719