xref: /freebsd/sys/net/if_ethersubr.c (revision 2357939bc239bd5334a169b62313806178dd8f30)
1 /*
2  * Copyright (c) 1982, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
30  * $FreeBSD$
31  */
32 
33 #include "opt_atalk.h"
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 #include "opt_ipx.h"
37 #include "opt_bdg.h"
38 #include "opt_mac.h"
39 #include "opt_netgraph.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/mac.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/random.h>
48 #include <sys/socket.h>
49 #include <sys/sockio.h>
50 #include <sys/sysctl.h>
51 
52 #include <net/if.h>
53 #include <net/netisr.h>
54 #include <net/route.h>
55 #include <net/if_llc.h>
56 #include <net/if_dl.h>
57 #include <net/if_types.h>
58 #include <net/bpf.h>
59 #include <net/ethernet.h>
60 #include <net/bridge.h>
61 #include <net/if_vlan_var.h>
62 
63 #if defined(INET) || defined(INET6)
64 #include <netinet/in.h>
65 #include <netinet/in_var.h>
66 #include <netinet/if_ether.h>
67 #include <netinet/ip_fw.h>
68 #include <netinet/ip_dummynet.h>
69 #endif
70 #ifdef INET6
71 #include <netinet6/nd6.h>
72 #endif
73 
74 #ifdef IPX
75 #include <netipx/ipx.h>
76 #include <netipx/ipx_if.h>
77 int (*ef_inputp)(struct ifnet*, struct ether_header *eh, struct mbuf *m);
78 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp,
79 		struct sockaddr *dst, short *tp, int *hlen);
80 #endif
81 
82 #ifdef NETATALK
83 #include <netatalk/at.h>
84 #include <netatalk/at_var.h>
85 #include <netatalk/at_extern.h>
86 
87 #define llc_snap_org_code llc_un.type_snap.org_code
88 #define llc_snap_ether_type llc_un.type_snap.ether_type
89 
90 extern u_char	at_org_code[3];
91 extern u_char	aarp_org_code[3];
92 #endif /* NETATALK */
93 
94 /* netgraph node hooks for ng_ether(4) */
95 void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
96 void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
97 int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
98 void	(*ng_ether_attach_p)(struct ifnet *ifp);
99 void	(*ng_ether_detach_p)(struct ifnet *ifp);
100 
101 void	(*vlan_input_p)(struct ifnet *, struct mbuf *);
102 
103 /* bridge support */
104 int do_bridge;
105 bridge_in_t *bridge_in_ptr;
106 bdg_forward_t *bdg_forward_ptr;
107 bdgtakeifaces_t *bdgtakeifaces_ptr;
108 struct bdg_softc *ifp2sc;
109 
110 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
111 			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
112 
113 static	int ether_resolvemulti(struct ifnet *, struct sockaddr **,
114 		struct sockaddr *);
115 
116 #define senderr(e) do { error = (e); goto bad;} while (0)
117 
118 int
119 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
120 	struct ip_fw **rule, int shared);
121 static int ether_ipfw;
122 
123 /*
124  * Ethernet output routine.
125  * Encapsulate a packet of type family for the local net.
126  * Use trailer local net encapsulation if enough data in first
127  * packet leaves a multiple of 512 bytes of data in remainder.
128  * Assumes that ifp is actually pointer to arpcom structure.
129  */
130 int
131 ether_output(struct ifnet *ifp, struct mbuf *m,
132 	struct sockaddr *dst, struct rtentry *rt0)
133 {
134 	short type;
135 	int error, hdrcmplt = 0;
136 	u_char esrc[ETHER_ADDR_LEN], edst[ETHER_ADDR_LEN];
137 	struct ether_header *eh;
138 	int loop_copy = 0;
139 	int hlen;	/* link layer header length */
140 
141 #ifdef MAC
142 	error = mac_check_ifnet_transmit(ifp, m);
143 	if (error)
144 		senderr(error);
145 #endif
146 
147 	if (ifp->if_flags & IFF_MONITOR)
148 		senderr(ENETDOWN);
149 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
150 		senderr(ENETDOWN);
151 
152 	hlen = ETHER_HDR_LEN;
153 	switch (dst->sa_family) {
154 #ifdef INET
155 	case AF_INET:
156 		error = arpresolve(ifp, rt0, m, dst, edst);
157 		if (error)
158 			return (error == EWOULDBLOCK ? 0 : error);
159 		type = htons(ETHERTYPE_IP);
160 		break;
161 	case AF_ARP:
162 	{
163 		struct arphdr *ah;
164 		ah = mtod(m, struct arphdr *);
165 		ah->ar_hrd = htons(ARPHRD_ETHER);
166 
167 		loop_copy = -1; /* if this is for us, don't do it */
168 
169 		switch(ntohs(ah->ar_op)) {
170 		case ARPOP_REVREQUEST:
171 		case ARPOP_REVREPLY:
172 			type = htons(ETHERTYPE_REVARP);
173 			break;
174 		case ARPOP_REQUEST:
175 		case ARPOP_REPLY:
176 		default:
177 			type = htons(ETHERTYPE_ARP);
178 			break;
179 		}
180 
181 		if (m->m_flags & M_BCAST)
182 			bcopy(ifp->if_broadcastaddr, edst, ETHER_ADDR_LEN);
183 		else
184 			bcopy(ar_tha(ah), edst, ETHER_ADDR_LEN);
185 
186 	}
187 	break;
188 #endif
189 #ifdef INET6
190 	case AF_INET6:
191 		error = nd6_storelladdr(ifp, rt0, m, dst, (u_char *)edst);
192 		if (error)
193 			return error;
194 		type = htons(ETHERTYPE_IPV6);
195 		break;
196 #endif
197 #ifdef IPX
198 	case AF_IPX:
199 		if (ef_outputp) {
200 		    error = ef_outputp(ifp, &m, dst, &type, &hlen);
201 		    if (error)
202 			goto bad;
203 		} else
204 		    type = htons(ETHERTYPE_IPX);
205 		bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
206 		    (caddr_t)edst, sizeof (edst));
207 		break;
208 #endif
209 #ifdef NETATALK
210 	case AF_APPLETALK:
211 	  {
212 	    struct at_ifaddr *aa;
213 
214 	    if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL)
215 		    senderr(EHOSTUNREACH); /* XXX */
216 	    if (!aarpresolve(ifp, m, (struct sockaddr_at *)dst, edst))
217 		    return (0);
218 	    /*
219 	     * In the phase 2 case, need to prepend an mbuf for the llc header.
220 	     */
221 	    if ( aa->aa_flags & AFA_PHASE2 ) {
222 		struct llc llc;
223 
224 		M_PREPEND(m, LLC_SNAPFRAMELEN, M_TRYWAIT);
225 		if (m == NULL)
226 			senderr(ENOBUFS);
227 		llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP;
228 		llc.llc_control = LLC_UI;
229 		bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code));
230 		llc.llc_snap_ether_type = htons( ETHERTYPE_AT );
231 		bcopy(&llc, mtod(m, caddr_t), LLC_SNAPFRAMELEN);
232 		type = htons(m->m_pkthdr.len);
233 		hlen = LLC_SNAPFRAMELEN + ETHER_HDR_LEN;
234 	    } else {
235 		type = htons(ETHERTYPE_AT);
236 	    }
237 	    break;
238 	  }
239 #endif /* NETATALK */
240 
241 	case pseudo_AF_HDRCMPLT:
242 		hdrcmplt = 1;
243 		eh = (struct ether_header *)dst->sa_data;
244 		(void)memcpy(esrc, eh->ether_shost, sizeof (esrc));
245 		/* FALLTHROUGH */
246 
247 	case AF_UNSPEC:
248 		loop_copy = -1; /* if this is for us, don't do it */
249 		eh = (struct ether_header *)dst->sa_data;
250 		(void)memcpy(edst, eh->ether_dhost, sizeof (edst));
251 		type = eh->ether_type;
252 		break;
253 
254 	default:
255 		if_printf(ifp, "can't handle af%d\n", dst->sa_family);
256 		senderr(EAFNOSUPPORT);
257 	}
258 
259 	/*
260 	 * Add local net header.  If no space in first mbuf,
261 	 * allocate another.
262 	 */
263 	M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
264 	if (m == NULL)
265 		senderr(ENOBUFS);
266 	eh = mtod(m, struct ether_header *);
267 	(void)memcpy(&eh->ether_type, &type,
268 		sizeof(eh->ether_type));
269 	(void)memcpy(eh->ether_dhost, edst, sizeof (edst));
270 	if (hdrcmplt)
271 		(void)memcpy(eh->ether_shost, esrc,
272 			sizeof(eh->ether_shost));
273 	else
274 		(void)memcpy(eh->ether_shost, IFP2AC(ifp)->ac_enaddr,
275 			sizeof(eh->ether_shost));
276 
277 	/*
278 	 * If a simplex interface, and the packet is being sent to our
279 	 * Ethernet address or a broadcast address, loopback a copy.
280 	 * XXX To make a simplex device behave exactly like a duplex
281 	 * device, we should copy in the case of sending to our own
282 	 * ethernet address (thus letting the original actually appear
283 	 * on the wire). However, we don't do that here for security
284 	 * reasons and compatibility with the original behavior.
285 	 */
286 	if ((ifp->if_flags & IFF_SIMPLEX) && (loop_copy != -1)) {
287 		int csum_flags = 0;
288 
289 		if (m->m_pkthdr.csum_flags & CSUM_IP)
290 			csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
291 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
292 			csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
293 
294 		if ((m->m_flags & M_BCAST) || (loop_copy > 0)) {
295 			struct mbuf *n;
296 
297 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
298 				n->m_pkthdr.csum_flags |= csum_flags;
299 				if (csum_flags & CSUM_DATA_VALID)
300 					n->m_pkthdr.csum_data = 0xffff;
301 				(void)if_simloop(ifp, n, dst->sa_family, hlen);
302 			} else
303 				ifp->if_iqdrops++;
304 		} else if (bcmp(eh->ether_dhost, eh->ether_shost,
305 				ETHER_ADDR_LEN) == 0) {
306 			m->m_pkthdr.csum_flags |= csum_flags;
307 			if (csum_flags & CSUM_DATA_VALID)
308 				m->m_pkthdr.csum_data = 0xffff;
309 			(void) if_simloop(ifp, m, dst->sa_family, hlen);
310 			return (0);	/* XXX */
311 		}
312 	}
313 
314 	/* Handle ng_ether(4) processing, if any */
315 	if (ng_ether_output_p != NULL) {
316 		if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
317 bad:			if (m != NULL)
318 				m_freem(m);
319 			return (error);
320 		}
321 		if (m == NULL)
322 			return (0);
323 	}
324 
325 	/* Continue with link-layer output */
326 	return ether_output_frame(ifp, m);
327 }
328 
329 /*
330  * Ethernet link layer output routine to send a raw frame to the device.
331  *
332  * This assumes that the 14 byte Ethernet header is present and contiguous
333  * in the first mbuf (if BRIDGE'ing).
334  */
335 int
336 ether_output_frame(struct ifnet *ifp, struct mbuf *m)
337 {
338 	struct ip_fw *rule = ip_dn_claim_rule(m);
339 
340 	if (rule == NULL && BDG_ACTIVE(ifp)) {
341 		/*
342 		 * Beware, the bridge code notices the null rcvif and
343 		 * uses that identify that it's being called from
344 		 * ether_output as opposd to ether_input.  Yech.
345 		 */
346 		m->m_pkthdr.rcvif = NULL;
347 		m = bdg_forward_ptr(m, ifp);
348 		if (m != NULL)
349 			m_freem(m);
350 		return (0);
351 	}
352 	if (IPFW_LOADED && ether_ipfw != 0) {
353 		if (ether_ipfw_chk(&m, ifp, &rule, 0) == 0) {
354 			if (m) {
355 				m_freem(m);
356 				return EACCES;	/* pkt dropped */
357 			} else
358 				return 0;	/* consumed e.g. in a pipe */
359 		}
360 	}
361 
362 	/*
363 	 * Queue message on interface, update output statistics if
364 	 * successful, and start output if interface not yet active.
365 	 */
366 	return (IF_HANDOFF(&ifp->if_snd, m, ifp) ? 0 : ENOBUFS);
367 }
368 
369 /*
370  * ipfw processing for ethernet packets (in and out).
371  * The second parameter is NULL from ether_demux, and ifp from
372  * ether_output_frame. This section of code could be used from
373  * bridge.c as well as long as we use some extra info
374  * to distinguish that case from ether_output_frame();
375  */
376 int
377 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
378 	struct ip_fw **rule, int shared)
379 {
380 	struct ether_header *eh;
381 	struct ether_header save_eh;
382 	struct mbuf *m;
383 	int i;
384 	struct ip_fw_args args;
385 
386 	if (*rule != NULL && fw_one_pass)
387 		return 1; /* dummynet packet, already partially processed */
388 
389 	/*
390 	 * I need some amt of data to be contiguous, and in case others need
391 	 * the packet (shared==1) also better be in the first mbuf.
392 	 */
393 	m = *m0;
394 	i = min( m->m_pkthdr.len, max_protohdr);
395 	if ( shared || m->m_len < i) {
396 		m = m_pullup(m, i);
397 		if (m == NULL) {
398 			*m0 = m;
399 			return 0;
400 		}
401 	}
402 	eh = mtod(m, struct ether_header *);
403 	save_eh = *eh;			/* save copy for restore below */
404 	m_adj(m, ETHER_HDR_LEN);	/* strip ethernet header */
405 
406 	args.m = m;		/* the packet we are looking at		*/
407 	args.oif = dst;		/* destination, if any			*/
408 	args.rule = *rule;	/* matching rule to restart		*/
409 	args.next_hop = NULL;	/* we do not support forward yet	*/
410 	args.eh = &save_eh;	/* MAC header for bridged/MAC packets	*/
411 	i = ip_fw_chk_ptr(&args);
412 	m = args.m;
413 	if (m != NULL) {
414 		/*
415 		 * Restore Ethernet header, as needed, in case the
416 		 * mbuf chain was replaced by ipfw.
417 		 */
418 		M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
419 		if (m == NULL) {
420 			*m0 = m;
421 			return 0;
422 		}
423 		if (eh != mtod(m, struct ether_header *))
424 			bcopy(&save_eh, mtod(m, struct ether_header *),
425 				ETHER_HDR_LEN);
426 	}
427 	*m0 = m;
428 	*rule = args.rule;
429 
430 	if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) /* drop */
431 		return 0;
432 
433 	if (i == 0) /* a PASS rule.  */
434 		return 1;
435 
436 	if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG)) {
437 		/*
438 		 * Pass the pkt to dummynet, which consumes it.
439 		 * If shared, make a copy and keep the original.
440 		 */
441 		if (shared) {
442 			m = m_copypacket(m, M_DONTWAIT);
443 			if (m == NULL)
444 				return 0;
445 		} else {
446 			/*
447 			 * Pass the original to dummynet and
448 			 * nothing back to the caller
449 			 */
450 			*m0 = NULL ;
451 		}
452 		ip_dn_io_ptr(m, (i & 0xffff),
453 			dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX, &args);
454 		return 0;
455 	}
456 	/*
457 	 * XXX at some point add support for divert/forward actions.
458 	 * If none of the above matches, we have to drop the pkt.
459 	 */
460 	return 0;
461 }
462 
463 /*
464  * Process a received Ethernet packet; the packet is in the
465  * mbuf chain m with the ethernet header at the front.
466  */
467 static void
468 ether_input(struct ifnet *ifp, struct mbuf *m)
469 {
470 	struct ether_header *eh;
471 	u_short etype;
472 
473 	/*
474 	 * Do consistency checks to verify assumptions
475 	 * made by code past this point.
476 	 */
477 	if ((m->m_flags & M_PKTHDR) == 0) {
478 		if_printf(ifp, "discard frame w/o packet header\n");
479 		ifp->if_ierrors++;
480 		m_freem(m);
481 		return;
482 	}
483 	if (m->m_len < ETHER_HDR_LEN) {
484 		/* XXX maybe should pullup? */
485 		if_printf(ifp, "discard frame w/o leading ethernet "
486 				"header (len %u pkt len %u)\n",
487 				m->m_len, m->m_pkthdr.len);
488 		ifp->if_ierrors++;
489 		m_freem(m);
490 		return;
491 	}
492 	eh = mtod(m, struct ether_header *);
493 	etype = ntohs(eh->ether_type);
494 	if (m->m_pkthdr.len >
495 	    ETHER_MAX_FRAME(ifp, etype, m->m_flags & M_HASFCS)) {
496 		if_printf(ifp, "discard oversize frame "
497 				"(ether type %x flags %x len %u > max %lu)\n",
498 				etype, m->m_flags, m->m_pkthdr.len,
499 				ETHER_MAX_FRAME(ifp, etype,
500 						m->m_flags & M_HASFCS));
501 		ifp->if_ierrors++;
502 		m_freem(m);
503 		return;
504 	}
505 	if (m->m_pkthdr.rcvif == NULL) {
506 		if_printf(ifp, "discard frame w/o interface pointer\n");
507 		ifp->if_ierrors++;
508 		m_freem(m);
509 		return;
510 	}
511 #ifdef DIAGNOSTIC
512 	if (m->m_pkthdr.rcvif != ifp) {
513 		if_printf(ifp, "Warning, frame marked as received on %s\n",
514 			m->m_pkthdr.rcvif->if_xname);
515 	}
516 #endif
517 
518 #ifdef MAC
519 	/*
520 	 * Tag the mbuf with an appropriate MAC label before any other
521 	 * consumers can get to it.
522 	 */
523 	mac_create_mbuf_from_ifnet(ifp, m);
524 #endif
525 
526 	/*
527 	 * Give bpf a chance at the packet.
528 	 */
529 	BPF_MTAP(ifp, m);
530 
531 	if (ifp->if_flags & IFF_MONITOR) {
532 		/*
533 		 * Interface marked for monitoring; discard packet.
534 		 */
535 		m_freem(m);
536 		return;
537 	}
538 
539 	/* If the CRC is still on the packet, trim it off. */
540 	if (m->m_flags & M_HASFCS) {
541 		m_adj(m, -ETHER_CRC_LEN);
542 		m->m_flags &= ~M_HASFCS;
543 	}
544 
545 	ifp->if_ibytes += m->m_pkthdr.len;
546 
547 	/* Handle ng_ether(4) processing, if any */
548 	if (ng_ether_input_p != NULL) {
549 		(*ng_ether_input_p)(ifp, &m);
550 		if (m == NULL)
551 			return;
552 	}
553 
554 	/* Check for bridging mode */
555 	if (BDG_ACTIVE(ifp) ) {
556 		struct ifnet *bif;
557 
558 		/*
559 		 * Check with bridging code to see how the packet
560 		 * should be handled.  Possibilities are:
561 		 *
562 		 *    BDG_BCAST		broadcast
563 		 *    BDG_MCAST		multicast
564 		 *    BDG_LOCAL		for local address, don't forward
565 		 *    BDG_DROP		discard
566 		 *    ifp		forward only to specified interface(s)
567 		 *
568 		 * Non-local destinations are handled by passing the
569 		 * packet back to the bridge code.
570 		 */
571 		bif = bridge_in_ptr(ifp, eh);
572 		if (bif == BDG_DROP) {		/* discard packet */
573 			m_freem(m);
574 			return;
575 		}
576 		if (bif != BDG_LOCAL) {		/* non-local, forward */
577 			m = bdg_forward_ptr(m, bif);
578 			/*
579 			 * The bridge may consume the packet if it's not
580 			 * supposed to be passed up or if a problem occurred
581 			 * while doing its job.  This is reflected by it
582 			 * returning a NULL mbuf pointer.
583 			 */
584 			if (m == NULL) {
585 				if (bif == BDG_BCAST || bif == BDG_MCAST)
586 					if_printf(ifp,
587 						"bridge dropped %s packet\n",
588 						bif == BDG_BCAST ? "broadcast" :
589 								   "multicast");
590 				return;
591 			}
592 			/*
593 			 * But in some cases the bridge may return the
594 			 * packet for us to free; sigh.
595 			 */
596 			if (bif != BDG_BCAST && bif != BDG_MCAST) {
597 				m_freem(m);
598 				return;
599 			}
600 		}
601 	}
602 
603 	ether_demux(ifp, m);
604 	/* First chunk of an mbuf contains good entropy */
605 	if (harvest.ethernet)
606 		random_harvest(m, 16, 3, 0, RANDOM_NET);
607 }
608 
609 /*
610  * Upper layer processing for a received Ethernet packet.
611  */
612 void
613 ether_demux(struct ifnet *ifp, struct mbuf *m)
614 {
615 	struct ether_header *eh;
616 	int isr;
617 	u_short ether_type;
618 #if defined(NETATALK)
619 	struct llc *l;
620 #endif
621 	struct ip_fw *rule = ip_dn_claim_rule(m);
622 
623 	KASSERT(ifp != NULL, ("ether_demux: NULL interface pointer"));
624 
625 	eh = mtod(m, struct ether_header *);
626 
627 	if (rule)	/* packet was already bridged */
628 		goto post_stats;
629 
630 	if (!(BDG_ACTIVE(ifp))) {
631 		/*
632 		 * Discard packet if upper layers shouldn't see it because it
633 		 * was unicast to a different Ethernet address. If the driver
634 		 * is working properly, then this situation can only happen
635 		 * when the interface is in promiscuous mode.
636 		 */
637 		if ((ifp->if_flags & IFF_PROMISC) != 0
638 		    && (eh->ether_dhost[0] & 1) == 0
639 		    && bcmp(eh->ether_dhost,
640 		      IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN) != 0
641 		    && (ifp->if_flags & IFF_PPROMISC) == 0) {
642 			    m_freem(m);
643 			    return;
644 		}
645 	}
646 
647 	/* Discard packet if interface is not up */
648 	if ((ifp->if_flags & IFF_UP) == 0) {
649 		m_freem(m);
650 		return;
651 	}
652 	if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
653 		if (bcmp(etherbroadcastaddr, eh->ether_dhost,
654 		    sizeof(etherbroadcastaddr)) == 0)
655 			m->m_flags |= M_BCAST;
656 		else
657 			m->m_flags |= M_MCAST;
658 	}
659 	if (m->m_flags & (M_BCAST|M_MCAST))
660 		ifp->if_imcasts++;
661 
662 post_stats:
663 	if (IPFW_LOADED && ether_ipfw != 0) {
664 		if (ether_ipfw_chk(&m, NULL, &rule, 0) == 0) {
665 			if (m)
666 				m_freem(m);
667 			return;
668 		}
669 	}
670 
671 	/*
672 	 * If VLANs are configured on the interface, check to
673 	 * see if the device performed the decapsulation and
674 	 * provided us with the tag.
675 	 */
676 	if (ifp->if_nvlans &&
677 	    m_tag_locate(m, MTAG_VLAN, MTAG_VLAN_TAG, NULL) != NULL) {
678 		/*
679 		 * vlan_input() will either recursively call ether_input()
680 		 * or drop the packet.
681 		 */
682 		KASSERT(vlan_input_p != NULL,("ether_input: VLAN not loaded!"));
683 		(*vlan_input_p)(ifp, m);
684 		return;
685 	}
686 
687 	ether_type = ntohs(eh->ether_type);
688 
689 	/*
690 	 * Handle protocols that expect to have the Ethernet header
691 	 * (and possibly FCS) intact.
692 	 */
693 	switch (ether_type) {
694 	case ETHERTYPE_VLAN:
695 		if (ifp->if_nvlans != 0) {
696 			KASSERT(vlan_input_p,("ether_input: VLAN not loaded!"));
697 			(*vlan_input_p)(ifp, m);
698 		} else {
699 			ifp->if_noproto++;
700 			m_freem(m);
701 		}
702 		return;
703 	}
704 
705 	/* Strip off Ethernet header. */
706 	m_adj(m, ETHER_HDR_LEN);
707 
708 	/* If the CRC is still on the packet, trim it off. */
709 	if (m->m_flags & M_HASFCS) {
710 		m_adj(m, -ETHER_CRC_LEN);
711 		m->m_flags &= ~M_HASFCS;
712 	}
713 
714 	switch (ether_type) {
715 #ifdef INET
716 	case ETHERTYPE_IP:
717 		if (ip_fastforward(m))
718 			return;
719 		isr = NETISR_IP;
720 		break;
721 
722 	case ETHERTYPE_ARP:
723 		if (ifp->if_flags & IFF_NOARP) {
724 			/* Discard packet if ARP is disabled on interface */
725 			m_freem(m);
726 			return;
727 		}
728 		isr = NETISR_ARP;
729 		break;
730 #endif
731 #ifdef IPX
732 	case ETHERTYPE_IPX:
733 		if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
734 			return;
735 		isr = NETISR_IPX;
736 		break;
737 #endif
738 #ifdef INET6
739 	case ETHERTYPE_IPV6:
740 		isr = NETISR_IPV6;
741 		break;
742 #endif
743 #ifdef NETATALK
744 	case ETHERTYPE_AT:
745 		isr = NETISR_ATALK1;
746 		break;
747 	case ETHERTYPE_AARP:
748 		isr = NETISR_AARP;
749 		break;
750 #endif /* NETATALK */
751 	default:
752 #ifdef IPX
753 		if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
754 			return;
755 #endif /* IPX */
756 #if defined(NETATALK)
757 		if (ether_type > ETHERMTU)
758 			goto discard;
759 		l = mtod(m, struct llc *);
760 		if (l->llc_dsap == LLC_SNAP_LSAP &&
761 		    l->llc_ssap == LLC_SNAP_LSAP &&
762 		    l->llc_control == LLC_UI) {
763 			if (bcmp(&(l->llc_snap_org_code)[0], at_org_code,
764 			    sizeof(at_org_code)) == 0 &&
765 			    ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
766 				m_adj(m, LLC_SNAPFRAMELEN);
767 				isr = NETISR_ATALK2;
768 				break;
769 			}
770 			if (bcmp(&(l->llc_snap_org_code)[0], aarp_org_code,
771 			    sizeof(aarp_org_code)) == 0 &&
772 			    ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) {
773 				m_adj(m, LLC_SNAPFRAMELEN);
774 				isr = NETISR_AARP;
775 				break;
776 			}
777 		}
778 #endif /* NETATALK */
779 		goto discard;
780 	}
781 	netisr_dispatch(isr, m);
782 	return;
783 
784 discard:
785 	/*
786 	 * Packet is to be discarded.  If netgraph is present,
787 	 * hand the packet to it for last chance processing;
788 	 * otherwise dispose of it.
789 	 */
790 	if (ng_ether_input_orphan_p != NULL) {
791 		/*
792 		 * Put back the ethernet header so netgraph has a
793 		 * consistent view of inbound packets.
794 		 */
795 		M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
796 		(*ng_ether_input_orphan_p)(ifp, m);
797 		return;
798 	}
799 	m_freem(m);
800 }
801 
802 /*
803  * Convert Ethernet address to printable (loggable) representation.
804  * This routine is for compatibility; it's better to just use
805  *
806  *	printf("%6D", <pointer to address>, ":");
807  *
808  * since there's no static buffer involved.
809  */
810 char *
811 ether_sprintf(const u_char *ap)
812 {
813 	static char etherbuf[18];
814 	snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":");
815 	return (etherbuf);
816 }
817 
818 /*
819  * Perform common duties while attaching to interface list
820  */
821 void
822 ether_ifattach(struct ifnet *ifp, const u_int8_t *llc)
823 {
824 	struct ifaddr *ifa;
825 	struct sockaddr_dl *sdl;
826 
827 	ifp->if_type = IFT_ETHER;
828 	ifp->if_addrlen = ETHER_ADDR_LEN;
829 	ifp->if_hdrlen = ETHER_HDR_LEN;
830 	if_attach(ifp);
831 	ifp->if_mtu = ETHERMTU;
832 	ifp->if_output = ether_output;
833 	ifp->if_input = ether_input;
834 	ifp->if_resolvemulti = ether_resolvemulti;
835 	if (ifp->if_baudrate == 0)
836 		ifp->if_baudrate = IF_Mbps(10);		/* just a default */
837 	ifp->if_broadcastaddr = etherbroadcastaddr;
838 
839 	ifa = ifaddr_byindex(ifp->if_index);
840 	KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
841 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
842 	sdl->sdl_type = IFT_ETHER;
843 	sdl->sdl_alen = ifp->if_addrlen;
844 	bcopy(llc, LLADDR(sdl), ifp->if_addrlen);
845 	/*
846 	 * XXX: This doesn't belong here; we do it until
847 	 * XXX:  all drivers are cleaned up
848 	 */
849 	if (llc != IFP2AC(ifp)->ac_enaddr)
850 		bcopy(llc, IFP2AC(ifp)->ac_enaddr, ifp->if_addrlen);
851 
852 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
853 	if (ng_ether_attach_p != NULL)
854 		(*ng_ether_attach_p)(ifp);
855 	if (BDG_LOADED)
856 		bdgtakeifaces_ptr();
857 
858 	/* Announce Ethernet MAC address. */
859 	if_printf(ifp, "Ethernet address: %6D\n", llc, ":");
860 }
861 
862 /*
863  * Perform common duties while detaching an Ethernet interface
864  */
865 void
866 ether_ifdetach(struct ifnet *ifp)
867 {
868 	if (ng_ether_detach_p != NULL)
869 		(*ng_ether_detach_p)(ifp);
870 	bpfdetach(ifp);
871 	if_detach(ifp);
872 	if (BDG_LOADED)
873 		bdgtakeifaces_ptr();
874 }
875 
876 SYSCTL_DECL(_net_link);
877 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
878 SYSCTL_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW,
879 	    &ether_ipfw,0,"Pass ether pkts through firewall");
880 
881 int
882 ether_ioctl(struct ifnet *ifp, int command, caddr_t data)
883 {
884 	struct ifaddr *ifa = (struct ifaddr *) data;
885 	struct ifreq *ifr = (struct ifreq *) data;
886 	int error = 0;
887 
888 	switch (command) {
889 	case SIOCSIFADDR:
890 		ifp->if_flags |= IFF_UP;
891 
892 		switch (ifa->ifa_addr->sa_family) {
893 #ifdef INET
894 		case AF_INET:
895 			ifp->if_init(ifp->if_softc);	/* before arpwhohas */
896 			arp_ifinit(ifp, ifa);
897 			break;
898 #endif
899 #ifdef IPX
900 		/*
901 		 * XXX - This code is probably wrong
902 		 */
903 		case AF_IPX:
904 			{
905 			struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr);
906 			struct arpcom *ac = IFP2AC(ifp);
907 
908 			if (ipx_nullhost(*ina))
909 				ina->x_host =
910 				    *(union ipx_host *)
911 				    ac->ac_enaddr;
912 			else {
913 				bcopy((caddr_t) ina->x_host.c_host,
914 				      (caddr_t) ac->ac_enaddr,
915 				      sizeof(ac->ac_enaddr));
916 			}
917 
918 			/*
919 			 * Set new address
920 			 */
921 			ifp->if_init(ifp->if_softc);
922 			break;
923 			}
924 #endif
925 		default:
926 			ifp->if_init(ifp->if_softc);
927 			break;
928 		}
929 		break;
930 
931 	case SIOCGIFADDR:
932 		{
933 			struct sockaddr *sa;
934 
935 			sa = (struct sockaddr *) & ifr->ifr_data;
936 			bcopy(IFP2AC(ifp)->ac_enaddr,
937 			      (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
938 		}
939 		break;
940 
941 	case SIOCSIFMTU:
942 		/*
943 		 * Set the interface MTU.
944 		 */
945 		if (ifr->ifr_mtu > ETHERMTU) {
946 			error = EINVAL;
947 		} else {
948 			ifp->if_mtu = ifr->ifr_mtu;
949 		}
950 		break;
951 	default:
952 		error = EINVAL;			/* XXX netbsd has ENOTTY??? */
953 		break;
954 	}
955 	return (error);
956 }
957 
958 static int
959 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
960 	struct sockaddr *sa)
961 {
962 	struct sockaddr_dl *sdl;
963 	struct sockaddr_in *sin;
964 #ifdef INET6
965 	struct sockaddr_in6 *sin6;
966 #endif
967 	u_char *e_addr;
968 
969 	switch(sa->sa_family) {
970 	case AF_LINK:
971 		/*
972 		 * No mapping needed. Just check that it's a valid MC address.
973 		 */
974 		sdl = (struct sockaddr_dl *)sa;
975 		e_addr = LLADDR(sdl);
976 		if ((e_addr[0] & 1) != 1)
977 			return EADDRNOTAVAIL;
978 		*llsa = 0;
979 		return 0;
980 
981 #ifdef INET
982 	case AF_INET:
983 		sin = (struct sockaddr_in *)sa;
984 		if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
985 			return EADDRNOTAVAIL;
986 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
987 		       M_WAITOK|M_ZERO);
988 		sdl->sdl_len = sizeof *sdl;
989 		sdl->sdl_family = AF_LINK;
990 		sdl->sdl_index = ifp->if_index;
991 		sdl->sdl_type = IFT_ETHER;
992 		sdl->sdl_alen = ETHER_ADDR_LEN;
993 		e_addr = LLADDR(sdl);
994 		ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
995 		*llsa = (struct sockaddr *)sdl;
996 		return 0;
997 #endif
998 #ifdef INET6
999 	case AF_INET6:
1000 		sin6 = (struct sockaddr_in6 *)sa;
1001 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1002 			/*
1003 			 * An IP6 address of 0 means listen to all
1004 			 * of the Ethernet multicast address used for IP6.
1005 			 * (This is used for multicast routers.)
1006 			 */
1007 			ifp->if_flags |= IFF_ALLMULTI;
1008 			*llsa = 0;
1009 			return 0;
1010 		}
1011 		if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
1012 			return EADDRNOTAVAIL;
1013 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1014 		       M_WAITOK|M_ZERO);
1015 		sdl->sdl_len = sizeof *sdl;
1016 		sdl->sdl_family = AF_LINK;
1017 		sdl->sdl_index = ifp->if_index;
1018 		sdl->sdl_type = IFT_ETHER;
1019 		sdl->sdl_alen = ETHER_ADDR_LEN;
1020 		e_addr = LLADDR(sdl);
1021 		ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
1022 		*llsa = (struct sockaddr *)sdl;
1023 		return 0;
1024 #endif
1025 
1026 	default:
1027 		/*
1028 		 * Well, the text isn't quite right, but it's the name
1029 		 * that counts...
1030 		 */
1031 		return EAFNOSUPPORT;
1032 	}
1033 }
1034 
1035 static moduledata_t ether_mod = {
1036 	"ether",
1037 	NULL,
1038 	0
1039 };
1040 
1041 DECLARE_MODULE(ether, ether_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
1042 MODULE_VERSION(ether, 1);
1043