xref: /freebsd/sys/net/if_ethersubr.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
34  * $FreeBSD$
35  */
36 
37 #include "opt_atalk.h"
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40 #include "opt_ipx.h"
41 #include "opt_bdg.h"
42 #include "opt_mac.h"
43 #include "opt_netgraph.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/mac.h>
49 #include <sys/malloc.h>
50 #include <sys/mbuf.h>
51 #include <sys/random.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/sysctl.h>
55 
56 #include <net/if.h>
57 #include <net/netisr.h>
58 #include <net/route.h>
59 #include <net/if_llc.h>
60 #include <net/if_dl.h>
61 #include <net/if_types.h>
62 #include <net/bpf.h>
63 #include <net/ethernet.h>
64 #include <net/bridge.h>
65 #include <net/if_vlan_var.h>
66 
67 #if defined(INET) || defined(INET6)
68 #include <netinet/in.h>
69 #include <netinet/in_var.h>
70 #include <netinet/if_ether.h>
71 #include <netinet/ip_fw.h>
72 #include <netinet/ip_dummynet.h>
73 #endif
74 #ifdef INET6
75 #include <netinet6/nd6.h>
76 #endif
77 
78 #ifdef IPX
79 #include <netipx/ipx.h>
80 #include <netipx/ipx_if.h>
81 int (*ef_inputp)(struct ifnet*, struct ether_header *eh, struct mbuf *m);
82 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp,
83 		struct sockaddr *dst, short *tp, int *hlen);
84 #endif
85 
86 #ifdef NS
87 #include <netns/ns.h>
88 #include <netns/ns_if.h>
89 ushort ns_nettype;
90 int ether_outputdebug = 0;
91 int ether_inputdebug = 0;
92 #endif
93 
94 #ifdef NETATALK
95 #include <netatalk/at.h>
96 #include <netatalk/at_var.h>
97 #include <netatalk/at_extern.h>
98 
99 #define llc_snap_org_code llc_un.type_snap.org_code
100 #define llc_snap_ether_type llc_un.type_snap.ether_type
101 
102 extern u_char	at_org_code[3];
103 extern u_char	aarp_org_code[3];
104 #endif /* NETATALK */
105 
106 /* netgraph node hooks for ng_ether(4) */
107 void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
108 void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
109 int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
110 void	(*ng_ether_attach_p)(struct ifnet *ifp);
111 void	(*ng_ether_detach_p)(struct ifnet *ifp);
112 
113 void	(*vlan_input_p)(struct ifnet *, struct mbuf *);
114 
115 /* bridge support */
116 int do_bridge;
117 bridge_in_t *bridge_in_ptr;
118 bdg_forward_t *bdg_forward_ptr;
119 bdgtakeifaces_t *bdgtakeifaces_ptr;
120 struct bdg_softc *ifp2sc;
121 
122 static	int ether_resolvemulti(struct ifnet *, struct sockaddr **,
123 		struct sockaddr *);
124 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
125 #define senderr(e) do { error = (e); goto bad;} while (0)
126 #define IFP2AC(IFP) ((struct arpcom *)IFP)
127 
128 int
129 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
130 	struct ip_fw **rule, int shared);
131 static int ether_ipfw;
132 
133 /*
134  * Ethernet output routine.
135  * Encapsulate a packet of type family for the local net.
136  * Use trailer local net encapsulation if enough data in first
137  * packet leaves a multiple of 512 bytes of data in remainder.
138  * Assumes that ifp is actually pointer to arpcom structure.
139  */
140 int
141 ether_output(ifp, m, dst, rt0)
142 	struct ifnet *ifp;
143 	struct mbuf *m;
144 	struct sockaddr *dst;
145 	struct rtentry *rt0;
146 {
147 	short type;
148 	int error = 0, hdrcmplt = 0;
149  	u_char esrc[6], edst[6];
150 	struct rtentry *rt;
151 	struct ether_header *eh;
152 	int loop_copy = 0;
153 	int hlen;	/* link layer header lenght */
154 	struct arpcom *ac = IFP2AC(ifp);
155 
156 #ifdef MAC
157 	error = mac_check_ifnet_transmit(ifp, m);
158 	if (error)
159 		senderr(error);
160 #endif
161 
162 	if (ifp->if_flags & IFF_MONITOR)
163 		senderr(ENETDOWN);
164 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
165 		senderr(ENETDOWN);
166 
167 	error = rt_check(&rt, &rt0, dst);
168 	if (error)
169 		goto bad;
170 
171 	hlen = ETHER_HDR_LEN;
172 	switch (dst->sa_family) {
173 #ifdef INET
174 	case AF_INET:
175 		if (!arpresolve(ifp, rt, m, dst, edst, rt0))
176 			return (0);	/* if not yet resolved */
177 		type = htons(ETHERTYPE_IP);
178 		break;
179 #endif
180 #ifdef INET6
181 	case AF_INET6:
182 		if (!nd6_storelladdr(&ac->ac_if, rt, m, dst, (u_char *)edst)) {
183 			/* Something bad happened */
184 			return(0);
185 		}
186 		type = htons(ETHERTYPE_IPV6);
187 		break;
188 #endif
189 #ifdef IPX
190 	case AF_IPX:
191 		if (ef_outputp) {
192 		    error = ef_outputp(ifp, &m, dst, &type, &hlen);
193 		    if (error)
194 			goto bad;
195 		} else
196 		    type = htons(ETHERTYPE_IPX);
197  		bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
198 		    (caddr_t)edst, sizeof (edst));
199 		break;
200 #endif
201 #ifdef NETATALK
202 	case AF_APPLETALK:
203 	  {
204 	    struct at_ifaddr *aa;
205 
206 	    if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) {
207 		    goto bad;
208 	    }
209 	    if (!aarpresolve(ac, m, (struct sockaddr_at *)dst, edst))
210 		    return (0);
211 	    /*
212 	     * In the phase 2 case, need to prepend an mbuf for the llc header.
213 	     * Since we must preserve the value of m, which is passed to us by
214 	     * value, we m_copy() the first mbuf, and use it for our llc header.
215 	     */
216 	    if ( aa->aa_flags & AFA_PHASE2 ) {
217 		struct llc llc;
218 
219 		M_PREPEND(m, LLC_SNAPFRAMELEN, M_TRYWAIT);
220 		llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP;
221 		llc.llc_control = LLC_UI;
222 		bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code));
223 		llc.llc_snap_ether_type = htons( ETHERTYPE_AT );
224 		bcopy(&llc, mtod(m, caddr_t), LLC_SNAPFRAMELEN);
225 		type = htons(m->m_pkthdr.len);
226 		hlen = LLC_SNAPFRAMELEN + ETHER_HDR_LEN;
227 	    } else {
228 		type = htons(ETHERTYPE_AT);
229 	    }
230 	    break;
231 	  }
232 #endif /* NETATALK */
233 #ifdef NS
234 	case AF_NS:
235 		switch(ns_nettype){
236 		default:
237 		case 0x8137: /* Novell Ethernet_II Ethernet TYPE II */
238 			type = 0x8137;
239 			break;
240 		case 0x0: /* Novell 802.3 */
241 			type = htons( m->m_pkthdr.len);
242 			break;
243 		case 0xe0e0: /* Novell 802.2 and Token-Ring */
244 			M_PREPEND(m, 3, M_TRYWAIT);
245 			type = htons( m->m_pkthdr.len);
246 			cp = mtod(m, u_char *);
247 			*cp++ = 0xE0;
248 			*cp++ = 0xE0;
249 			*cp++ = 0x03;
250 			break;
251 		}
252  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
253 		    (caddr_t)edst, sizeof (edst));
254 		/*
255 		 * XXX if ns_thishost is the same as the node's ethernet
256 		 * address then just the default code will catch this anyhow.
257 		 * So I'm not sure if this next clause should be here at all?
258 		 * [JRE]
259 		 */
260 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst))){
261 			m->m_pkthdr.rcvif = ifp;
262 			inq = &nsintrq;
263 			if (IF_HANDOFF(inq, m, NULL))
264 				schednetisr(NETISR_NS);
265 			return (error);
266 		}
267 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_broadhost, sizeof(edst))){
268 			m->m_flags |= M_BCAST;
269 		}
270 		break;
271 #endif /* NS */
272 
273 	case pseudo_AF_HDRCMPLT:
274 		hdrcmplt = 1;
275 		eh = (struct ether_header *)dst->sa_data;
276 		(void)memcpy(esrc, eh->ether_shost, sizeof (esrc));
277 		/* FALLTHROUGH */
278 
279 	case AF_UNSPEC:
280 		loop_copy = -1; /* if this is for us, don't do it */
281 		eh = (struct ether_header *)dst->sa_data;
282  		(void)memcpy(edst, eh->ether_dhost, sizeof (edst));
283 		type = eh->ether_type;
284 		break;
285 
286 	default:
287 		if_printf(ifp, "can't handle af%d\n", dst->sa_family);
288 		senderr(EAFNOSUPPORT);
289 	}
290 
291 	/*
292 	 * Add local net header.  If no space in first mbuf,
293 	 * allocate another.
294 	 */
295 	M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
296 	if (m == 0)
297 		senderr(ENOBUFS);
298 	eh = mtod(m, struct ether_header *);
299 	(void)memcpy(&eh->ether_type, &type,
300 		sizeof(eh->ether_type));
301  	(void)memcpy(eh->ether_dhost, edst, sizeof (edst));
302 	if (hdrcmplt)
303 		(void)memcpy(eh->ether_shost, esrc,
304 			sizeof(eh->ether_shost));
305 	else
306 		(void)memcpy(eh->ether_shost, ac->ac_enaddr,
307 			sizeof(eh->ether_shost));
308 
309 	/*
310 	 * If a simplex interface, and the packet is being sent to our
311 	 * Ethernet address or a broadcast address, loopback a copy.
312 	 * XXX To make a simplex device behave exactly like a duplex
313 	 * device, we should copy in the case of sending to our own
314 	 * ethernet address (thus letting the original actually appear
315 	 * on the wire). However, we don't do that here for security
316 	 * reasons and compatibility with the original behavior.
317 	 */
318 	if ((ifp->if_flags & IFF_SIMPLEX) && (loop_copy != -1)) {
319 		int csum_flags = 0;
320 
321 		if (m->m_pkthdr.csum_flags & CSUM_IP)
322 			csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
323 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
324 			csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
325 		if ((m->m_flags & M_BCAST) || (loop_copy > 0)) {
326 			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
327 
328 			n->m_pkthdr.csum_flags |= csum_flags;
329 			if (csum_flags & CSUM_DATA_VALID)
330 				n->m_pkthdr.csum_data = 0xffff;
331 
332 			(void) if_simloop(ifp, n, dst->sa_family, hlen);
333 		} else if (bcmp(eh->ether_dhost,
334 		    eh->ether_shost, ETHER_ADDR_LEN) == 0) {
335 			m->m_pkthdr.csum_flags |= csum_flags;
336 			if (csum_flags & CSUM_DATA_VALID)
337 				m->m_pkthdr.csum_data = 0xffff;
338 			(void) if_simloop(ifp, m, dst->sa_family, hlen);
339 			return (0);	/* XXX */
340 		}
341 	}
342 
343 	/* Handle ng_ether(4) processing, if any */
344 	if (ng_ether_output_p != NULL) {
345 		if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
346 bad:			if (m != NULL)
347 				m_freem(m);
348 			return (error);
349 		}
350 		if (m == NULL)
351 			return (0);
352 	}
353 
354 	/* Continue with link-layer output */
355 	return ether_output_frame(ifp, m);
356 }
357 
358 /*
359  * Ethernet link layer output routine to send a raw frame to the device.
360  *
361  * This assumes that the 14 byte Ethernet header is present and contiguous
362  * in the first mbuf (if BRIDGE'ing).
363  */
364 int
365 ether_output_frame(struct ifnet *ifp, struct mbuf *m)
366 {
367 	struct ip_fw *rule = NULL;
368 
369 	/* Extract info from dummynet tag, ignore others */
370 	for (; m->m_type == MT_TAG; m = m->m_next)
371 		if (m->m_flags == PACKET_TAG_DUMMYNET)
372 			rule = ((struct dn_pkt *)m)->rule;
373 
374 	if (rule == NULL && BDG_ACTIVE(ifp)) {
375 		/*
376 		 * Beware, the bridge code notices the null rcvif and
377 		 * uses that identify that it's being called from
378 		 * ether_output as opposd to ether_input.  Yech.
379 		 */
380 		m->m_pkthdr.rcvif = NULL;
381 		m = bdg_forward_ptr(m, ifp);
382 		if (m != NULL)
383 			m_freem(m);
384 		return (0);
385 	}
386 	if (IPFW_LOADED && ether_ipfw != 0) {
387 		if (ether_ipfw_chk(&m, ifp, &rule, 0) == 0) {
388 			if (m) {
389 				m_freem(m);
390 				return ENOBUFS;	/* pkt dropped */
391 			} else
392 				return 0;	/* consumed e.g. in a pipe */
393 		}
394 	}
395 
396 	/*
397 	 * Queue message on interface, update output statistics if
398 	 * successful, and start output if interface not yet active.
399 	 */
400 	return (IF_HANDOFF(&ifp->if_snd, m, ifp) ? 0 : ENOBUFS);
401 }
402 
403 /*
404  * ipfw processing for ethernet packets (in and out).
405  * The second parameter is NULL from ether_demux, and ifp from
406  * ether_output_frame. This section of code could be used from
407  * bridge.c as well as long as we use some extra info
408  * to distinguish that case from ether_output_frame();
409  */
410 int
411 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
412 	struct ip_fw **rule, int shared)
413 {
414 	struct ether_header *eh;
415 	struct ether_header save_eh;
416 	struct mbuf *m;
417 	int i;
418 	struct ip_fw_args args;
419 
420 	if (*rule != NULL && fw_one_pass)
421 		return 1; /* dummynet packet, already partially processed */
422 
423 	/*
424 	 * I need some amt of data to be contiguous, and in case others need
425 	 * the packet (shared==1) also better be in the first mbuf.
426 	 */
427 	m = *m0;
428 	i = min( m->m_pkthdr.len, max_protohdr);
429 	if ( shared || m->m_len < i) {
430 		m = m_pullup(m, i);
431 		if (m == NULL) {
432 			*m0 = m;
433 			return 0;
434 		}
435 	}
436 	eh = mtod(m, struct ether_header *);
437 	save_eh = *eh;			/* save copy for restore below */
438 	m_adj(m, ETHER_HDR_LEN);	/* strip ethernet header */
439 
440 	args.m = m;		/* the packet we are looking at		*/
441 	args.oif = dst;		/* destination, if any			*/
442 	args.divert_rule = 0;	/* we do not support divert yet		*/
443 	args.rule = *rule;	/* matching rule to restart		*/
444 	args.next_hop = NULL;	/* we do not support forward yet	*/
445 	args.eh = &save_eh;	/* MAC header for bridged/MAC packets	*/
446 	i = ip_fw_chk_ptr(&args);
447 	m = args.m;
448 	if (m != NULL) {
449 		/*
450 		 * Restore Ethernet header, as needed, in case the
451 		 * mbuf chain was replaced by ipfw.
452 		 */
453 		M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
454 		if (m == NULL) {
455 			*m0 = m;
456 			return 0;
457 		}
458 		if (eh != mtod(m, struct ether_header *))
459 			bcopy(&save_eh, mtod(m, struct ether_header *),
460 				ETHER_HDR_LEN);
461 	}
462 	*m0 = m;
463 	*rule = args.rule;
464 
465 	if ( (i & IP_FW_PORT_DENY_FLAG) || m == NULL) /* drop */
466 		return 0;
467 
468 	if (i == 0) /* a PASS rule.  */
469 		return 1;
470 
471 	if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG)) {
472 		/*
473 		 * Pass the pkt to dummynet, which consumes it.
474 		 * If shared, make a copy and keep the original.
475 		 */
476 		if (shared) {
477 			m = m_copypacket(m, M_DONTWAIT);
478 			if (m == NULL)
479 				return 0;
480 		} else {
481 			/*
482 			 * Pass the original to dummynet and
483 			 * nothing back to the caller
484 			 */
485 			*m0 = NULL ;
486 		}
487 		ip_dn_io_ptr(m, (i & 0xffff),
488 			dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX, &args);
489 		return 0;
490 	}
491 	/*
492 	 * XXX at some point add support for divert/forward actions.
493 	 * If none of the above matches, we have to drop the pkt.
494 	 */
495 	return 0;
496 }
497 
498 /*
499  * Process a received Ethernet packet; the packet is in the
500  * mbuf chain m with the ethernet header at the front.
501  */
502 static void
503 ether_input(struct ifnet *ifp, struct mbuf *m)
504 {
505 	struct ether_header *eh;
506 	u_short etype;
507 
508 	/*
509 	 * Do consistency checks to verify assumptions
510 	 * made by code past this point.
511 	 */
512 	if ((m->m_flags & M_PKTHDR) == 0) {
513 		if_printf(ifp, "discard frame w/o packet header\n");
514 		ifp->if_ierrors++;
515 		m_freem(m);
516 		return;
517 	}
518 	if (m->m_len < ETHER_HDR_LEN) {
519 		/* XXX maybe should pullup? */
520 		if_printf(ifp, "discard frame w/o leading ethernet "
521 				"header (len %u pkt len %u)\n",
522 				m->m_len, m->m_pkthdr.len);
523 		ifp->if_ierrors++;
524 		m_freem(m);
525 		return;
526 	}
527 	eh = mtod(m, struct ether_header *);
528 	etype = ntohs(eh->ether_type);
529 	if (m->m_pkthdr.len >
530 	    ETHER_MAX_FRAME(ifp, etype, m->m_flags & M_HASFCS)) {
531 		if_printf(ifp, "discard oversize frame "
532 				"(ether type %x flags %x len %u > max %lu)\n",
533 				etype, m->m_flags, m->m_pkthdr.len,
534 				ETHER_MAX_FRAME(ifp, etype,
535 						m->m_flags & M_HASFCS));
536 		ifp->if_ierrors++;
537 		m_freem(m);
538 		return;
539 	}
540 	if (m->m_pkthdr.rcvif == NULL) {
541 		if_printf(ifp, "discard frame w/o interface pointer\n");
542 		ifp->if_ierrors++;
543 		m_freem(m);
544 		return;
545 	}
546 #ifdef DIAGNOSTIC
547 	if (m->m_pkthdr.rcvif != ifp) {
548 		if_printf(ifp, "Warning, frame marked as received on %s%u\n",
549 			m->m_pkthdr.rcvif->if_name,
550 			m->m_pkthdr.rcvif->if_unit);
551 	}
552 #endif
553 
554 	/*
555 	 * Give bpf a chance at the packet.
556 	 */
557 	BPF_MTAP(ifp, m);
558 
559 	if (ifp->if_flags & IFF_MONITOR) {
560 		/*
561 		 * Interface marked for monitoring; discard packet.
562 		 */
563 		m_freem(m);
564 		return;
565 	}
566 
567 	/* If the CRC is still on the packet, trim it off. */
568 	if (m->m_flags & M_HASFCS) {
569 		m_adj(m, -ETHER_CRC_LEN);
570 		m->m_flags &= ~M_HASFCS;
571 	}
572 
573 #ifdef MAC
574 	mac_create_mbuf_from_ifnet(ifp, m);
575 #endif
576 
577 	ifp->if_ibytes += m->m_pkthdr.len;
578 
579 	/* Handle ng_ether(4) processing, if any */
580 	if (ng_ether_input_p != NULL) {
581 		(*ng_ether_input_p)(ifp, &m);
582 		if (m == NULL)
583 			return;
584 	}
585 
586 	/* Check for bridging mode */
587 	if (BDG_ACTIVE(ifp) ) {
588 		struct ifnet *bif;
589 
590 		/*
591 		 * Check with bridging code to see how the packet
592 		 * should be handled.  Possibilities are:
593 		 *
594 		 *    BDG_BCAST		broadcast
595 		 *    BDG_MCAST		multicast
596 		 *    BDG_LOCAL		for local address, don't forward
597 		 *    BDG_DROP		discard
598 		 *    ifp		forward only to specified interface(s)
599 		 *
600 		 * Non-local destinations are handled by passing the
601 		 * packet back to the bridge code.
602 		 */
603 		bif = bridge_in_ptr(ifp, eh);
604 		if (bif == BDG_DROP) {		/* discard packet */
605 			m_freem(m);
606 			return;
607 		}
608 		if (bif != BDG_LOCAL) {		/* non-local, forward */
609 			m = bdg_forward_ptr(m, bif);
610 			/*
611 			 * The bridge may consume the packet if it's not
612 			 * supposed to be passed up or if a problem occurred
613 			 * while doing its job.  This is reflected by it
614 			 * returning a NULL mbuf pointer.
615 			 */
616 			if (m == NULL) {
617 				if (bif == BDG_BCAST || bif == BDG_MCAST)
618 					if_printf(ifp,
619 						"bridge dropped %s packet\n",
620 						bif == BDG_BCAST ? "broadcast" :
621 								   "multicast");
622 				return;
623 			}
624 			/*
625 			 * But in some cases the bridge may return the
626 			 * packet for us to free; sigh.
627 			 */
628 			if (bif != BDG_BCAST && bif != BDG_MCAST) {
629 				m_freem(m);
630 				return;
631 			}
632 		}
633 	}
634 
635 	ether_demux(ifp, m);
636 	/* First chunk of an mbuf contains good entropy */
637 	if (harvest.ethernet)
638 		random_harvest(m, 16, 3, 0, RANDOM_NET);
639 }
640 
641 /*
642  * Upper layer processing for a received Ethernet packet.
643  */
644 void
645 ether_demux(struct ifnet *ifp, struct mbuf *m)
646 {
647 	struct ether_header *eh;
648 	struct ifqueue *inq;
649 	u_short ether_type;
650 #if defined(NETATALK)
651 	struct llc *l;
652 #endif
653 	struct ip_fw *rule = NULL;
654 
655 	/* Extract info from dummynet tag, ignore others */
656 	for (;m->m_type == MT_TAG; m = m->m_next)
657 		if (m->m_flags == PACKET_TAG_DUMMYNET) {
658 			rule = ((struct dn_pkt *)m)->rule;
659 			ifp = m->m_next->m_pkthdr.rcvif;
660 		}
661 
662 	KASSERT(ifp != NULL, ("ether_demux: NULL interface pointer"));
663 
664 	eh = mtod(m, struct ether_header *);
665 
666 	if (rule)	/* packet was already bridged */
667 		goto post_stats;
668 
669 	if (!(BDG_ACTIVE(ifp))) {
670 		/*
671 		 * Discard packet if upper layers shouldn't see it because it
672 		 * was unicast to a different Ethernet address. If the driver
673 		 * is working properly, then this situation can only happen
674 		 * when the interface is in promiscuous mode.
675 		 */
676 		if ((ifp->if_flags & IFF_PROMISC) != 0
677 		    && (eh->ether_dhost[0] & 1) == 0
678 		    && bcmp(eh->ether_dhost,
679 		      IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN) != 0
680 		    && (ifp->if_flags & IFF_PPROMISC) == 0) {
681 			    m_freem(m);
682 			    return;
683 		}
684 	}
685 
686 	/* Discard packet if interface is not up */
687 	if ((ifp->if_flags & IFF_UP) == 0) {
688 		m_freem(m);
689 		return;
690 	}
691 	if (eh->ether_dhost[0] & 1) {
692 		if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
693 			 sizeof(etherbroadcastaddr)) == 0)
694 			m->m_flags |= M_BCAST;
695 		else
696 			m->m_flags |= M_MCAST;
697 	}
698 	if (m->m_flags & (M_BCAST|M_MCAST))
699 		ifp->if_imcasts++;
700 
701 post_stats:
702 	if (IPFW_LOADED && ether_ipfw != 0) {
703 		if (ether_ipfw_chk(&m, NULL, &rule, 0) == 0) {
704 			if (m)
705 				m_freem(m);
706 			return;
707 		}
708 	}
709 
710 	/*
711 	 * If VLANs are configured on the interface, check to
712 	 * see if the device performed the decapsulation and
713 	 * provided us with the tag.
714 	 */
715 	if (ifp->if_nvlans &&
716 	    m_tag_locate(m, MTAG_VLAN, MTAG_VLAN_TAG, NULL) != NULL) {
717 		/*
718 		 * vlan_input() will either recursively call ether_input()
719 		 * or drop the packet.
720 		 */
721 		KASSERT(vlan_input_p != NULL,("ether_input: VLAN not loaded!"));
722 		(*vlan_input_p)(ifp, m);
723 		return;
724 	}
725 
726 	ether_type = ntohs(eh->ether_type);
727 
728 	/*
729 	 * Handle protocols that expect to have the Ethernet header
730 	 * (and possibly FCS) intact.
731 	 */
732 	switch (ether_type) {
733 	case ETHERTYPE_VLAN:
734 		if (ifp->if_nvlans != 0) {
735 			KASSERT(vlan_input_p,("ether_input: VLAN not loaded!"));
736 			(*vlan_input_p)(ifp, m);
737 		} else {
738 			ifp->if_noproto++;
739 			m_freem(m);
740 		}
741 		return;
742 	}
743 
744 	/* Strip off Ethernet header. */
745 	m_adj(m, ETHER_HDR_LEN);
746 
747 	/* If the CRC is still on the packet, trim it off. */
748 	if (m->m_flags & M_HASFCS) {
749 		m_adj(m, -ETHER_CRC_LEN);
750 		m->m_flags &= ~M_HASFCS;
751 	}
752 
753 	switch (ether_type) {
754 #ifdef INET
755 	case ETHERTYPE_IP:
756 		if (ipflow_fastforward(m))
757 			return;
758 		schednetisr(NETISR_IP);
759 		inq = &ipintrq;
760 		break;
761 
762 	case ETHERTYPE_ARP:
763 		if (ifp->if_flags & IFF_NOARP) {
764 			/* Discard packet if ARP is disabled on interface */
765 			m_freem(m);
766 			return;
767 		}
768 		schednetisr(NETISR_ARP);
769 		inq = &arpintrq;
770 		break;
771 #endif
772 #ifdef IPX
773 	case ETHERTYPE_IPX:
774 		if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
775 			return;
776 		schednetisr(NETISR_IPX);
777 		inq = &ipxintrq;
778 		break;
779 #endif
780 #ifdef INET6
781 	case ETHERTYPE_IPV6:
782 		schednetisr(NETISR_IPV6);
783 		inq = &ip6intrq;
784 		break;
785 #endif
786 #ifdef NS
787 	case 0x8137: /* Novell Ethernet_II Ethernet TYPE II */
788 		schednetisr(NETISR_NS);
789 		inq = &nsintrq;
790 		break;
791 
792 #endif /* NS */
793 #ifdef NETATALK
794         case ETHERTYPE_AT:
795                 schednetisr(NETISR_ATALK);
796                 inq = &atintrq1;
797                 break;
798         case ETHERTYPE_AARP:
799 		/* probably this should be done with a NETISR as well */
800                 aarpinput(IFP2AC(ifp), m); /* XXX */
801                 return;
802 #endif /* NETATALK */
803 	default:
804 #ifdef IPX
805 		if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
806 			return;
807 #endif /* IPX */
808 #ifdef NS
809 		checksum = mtod(m, ushort *);
810 		/* Novell 802.3 */
811 		if ((ether_type <= ETHERMTU) &&
812 			((*checksum == 0xffff) || (*checksum == 0xE0E0))){
813 			if(*checksum == 0xE0E0) {
814 				m->m_pkthdr.len -= 3;
815 				m->m_len -= 3;
816 				m->m_data += 3;
817 			}
818 				schednetisr(NETISR_NS);
819 				inq = &nsintrq;
820 				break;
821 		}
822 #endif /* NS */
823 #if defined(NETATALK)
824 		if (ether_type > ETHERMTU)
825 			goto discard;
826 		l = mtod(m, struct llc *);
827 		switch (l->llc_dsap) {
828 		case LLC_SNAP_LSAP:
829 		    switch (l->llc_control) {
830 		    case LLC_UI:
831 			if (l->llc_ssap != LLC_SNAP_LSAP)
832 			    goto discard;
833 
834 			if (Bcmp(&(l->llc_snap_org_code)[0], at_org_code,
835 				   sizeof(at_org_code)) == 0 &&
836 			     ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
837 			    inq = &atintrq2;
838 			    m_adj( m, LLC_SNAPFRAMELEN);
839 			    schednetisr(NETISR_ATALK);
840 			    break;
841 			}
842 
843 			if (Bcmp(&(l->llc_snap_org_code)[0], aarp_org_code,
844 				   sizeof(aarp_org_code)) == 0 &&
845 			     ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) {
846 			    m_adj( m, LLC_SNAPFRAMELEN);
847 			    aarpinput(IFP2AC(ifp), m); /* XXX */
848 			    return;
849 			}
850 
851 		    default:
852 			goto discard;
853 		    }
854 		    break;
855 		default:
856 			goto discard;
857 		}
858 #else /* NETATALK */
859 		goto discard;
860 #endif /* NETATALK */
861 	}
862 
863 	(void) IF_HANDOFF(inq, m, NULL);
864 	return;
865 discard:
866 	/*
867 	 * Packet is to be discarded.  If netgraph is present,
868 	 * hand the packet to it for last chance processing;
869 	 * otherwise dispose of it.
870 	 */
871 	if (ng_ether_input_orphan_p != NULL) {
872 		/*
873 		 * Put back the ethernet header so netgraph has a
874 		 * consistent view of inbound packets.
875 		 */
876 		M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
877 		(*ng_ether_input_orphan_p)(ifp, m);
878 		return;
879 	}
880 	m_freem(m);
881 }
882 
883 /*
884  * Convert Ethernet address to printable (loggable) representation.
885  * This routine is for compatibility; it's better to just use
886  *
887  *	printf("%6D", <pointer to address>, ":");
888  *
889  * since there's no static buffer involved.
890  */
891 char *
892 ether_sprintf(const u_char *ap)
893 {
894 	static char etherbuf[18];
895 	snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":");
896 	return (etherbuf);
897 }
898 
899 /*
900  * Perform common duties while attaching to interface list
901  */
902 void
903 ether_ifattach(struct ifnet *ifp, const u_int8_t *llc)
904 {
905 	struct ifaddr *ifa;
906 	struct sockaddr_dl *sdl;
907 
908 	ifp->if_type = IFT_ETHER;
909 	ifp->if_addrlen = ETHER_ADDR_LEN;
910 	ifp->if_hdrlen = ETHER_HDR_LEN;
911 	if_attach(ifp);
912 	ifp->if_mtu = ETHERMTU;
913 	ifp->if_output = ether_output;
914 	ifp->if_input = ether_input;
915 	ifp->if_resolvemulti = ether_resolvemulti;
916 	if (ifp->if_baudrate == 0)
917 		ifp->if_baudrate = IF_Mbps(10);		/* just a default */
918 	ifp->if_broadcastaddr = etherbroadcastaddr;
919 
920 	ifa = ifaddr_byindex(ifp->if_index);
921 	KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
922 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
923 	sdl->sdl_type = IFT_ETHER;
924 	sdl->sdl_alen = ifp->if_addrlen;
925 	bcopy(llc, LLADDR(sdl), ifp->if_addrlen);
926 	/*
927 	 * XXX: This doesn't belong here; we do it until
928 	 * XXX:  all drivers are cleaned up
929 	 */
930 	if (llc != IFP2AC(ifp)->ac_enaddr)
931 		bcopy(llc, IFP2AC(ifp)->ac_enaddr, ifp->if_addrlen);
932 
933 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
934 	if (ng_ether_attach_p != NULL)
935 		(*ng_ether_attach_p)(ifp);
936 	if (BDG_LOADED)
937 		bdgtakeifaces_ptr();
938 }
939 
940 /*
941  * Perform common duties while detaching an Ethernet interface
942  */
943 void
944 ether_ifdetach(struct ifnet *ifp)
945 {
946 	if (ng_ether_detach_p != NULL)
947 		(*ng_ether_detach_p)(ifp);
948 	bpfdetach(ifp);
949 	if_detach(ifp);
950 	if (BDG_LOADED)
951 		bdgtakeifaces_ptr();
952 }
953 
954 SYSCTL_DECL(_net_link);
955 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
956 SYSCTL_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW,
957 	    &ether_ipfw,0,"Pass ether pkts through firewall");
958 
959 int
960 ether_ioctl(ifp, command, data)
961 	struct ifnet *ifp;
962 	int command;
963 	caddr_t data;
964 {
965 	struct ifaddr *ifa = (struct ifaddr *) data;
966 	struct ifreq *ifr = (struct ifreq *) data;
967 	int error = 0;
968 
969 	switch (command) {
970 	case SIOCSIFADDR:
971 		ifp->if_flags |= IFF_UP;
972 
973 		switch (ifa->ifa_addr->sa_family) {
974 #ifdef INET
975 		case AF_INET:
976 			ifp->if_init(ifp->if_softc);	/* before arpwhohas */
977 			arp_ifinit(ifp, ifa);
978 			break;
979 #endif
980 #ifdef IPX
981 		/*
982 		 * XXX - This code is probably wrong
983 		 */
984 		case AF_IPX:
985 			{
986 			struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr);
987 			struct arpcom *ac = IFP2AC(ifp);
988 
989 			if (ipx_nullhost(*ina))
990 				ina->x_host =
991 				    *(union ipx_host *)
992 			            ac->ac_enaddr;
993 			else {
994 				bcopy((caddr_t) ina->x_host.c_host,
995 				      (caddr_t) ac->ac_enaddr,
996 				      sizeof(ac->ac_enaddr));
997 			}
998 
999 			/*
1000 			 * Set new address
1001 			 */
1002 			ifp->if_init(ifp->if_softc);
1003 			break;
1004 			}
1005 #endif
1006 #ifdef NS
1007 		/*
1008 		 * XXX - This code is probably wrong
1009 		 */
1010 		case AF_NS:
1011 		{
1012 			struct ns_addr *ina = &(IA_SNS(ifa)->sns_addr);
1013 			struct arpcom *ac = IFP2AC(ifp);
1014 
1015 			if (ns_nullhost(*ina))
1016 				ina->x_host =
1017 				    *(union ns_host *) (ac->ac_enaddr);
1018 			else {
1019 				bcopy((caddr_t) ina->x_host.c_host,
1020 				      (caddr_t) ac->ac_enaddr,
1021 				      sizeof(ac->ac_enaddr));
1022 			}
1023 
1024 			/*
1025 			 * Set new address
1026 			 */
1027 			ifp->if_init(ifp->if_softc);
1028 			break;
1029 		}
1030 #endif
1031 		default:
1032 			ifp->if_init(ifp->if_softc);
1033 			break;
1034 		}
1035 		break;
1036 
1037 	case SIOCGIFADDR:
1038 		{
1039 			struct sockaddr *sa;
1040 
1041 			sa = (struct sockaddr *) & ifr->ifr_data;
1042 			bcopy(IFP2AC(ifp)->ac_enaddr,
1043 			      (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
1044 		}
1045 		break;
1046 
1047 	case SIOCSIFMTU:
1048 		/*
1049 		 * Set the interface MTU.
1050 		 */
1051 		if (ifr->ifr_mtu > ETHERMTU) {
1052 			error = EINVAL;
1053 		} else {
1054 			ifp->if_mtu = ifr->ifr_mtu;
1055 		}
1056 		break;
1057 	default:
1058 		error = EINVAL;			/* XXX netbsd has ENOTTY??? */
1059 		break;
1060 	}
1061 	return (error);
1062 }
1063 
1064 static int
1065 ether_resolvemulti(ifp, llsa, sa)
1066 	struct ifnet *ifp;
1067 	struct sockaddr **llsa;
1068 	struct sockaddr *sa;
1069 {
1070 	struct sockaddr_dl *sdl;
1071 	struct sockaddr_in *sin;
1072 #ifdef INET6
1073 	struct sockaddr_in6 *sin6;
1074 #endif
1075 	u_char *e_addr;
1076 
1077 	switch(sa->sa_family) {
1078 	case AF_LINK:
1079 		/*
1080 		 * No mapping needed. Just check that it's a valid MC address.
1081 		 */
1082 		sdl = (struct sockaddr_dl *)sa;
1083 		e_addr = LLADDR(sdl);
1084 		if ((e_addr[0] & 1) != 1)
1085 			return EADDRNOTAVAIL;
1086 		*llsa = 0;
1087 		return 0;
1088 
1089 #ifdef INET
1090 	case AF_INET:
1091 		sin = (struct sockaddr_in *)sa;
1092 		if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
1093 			return EADDRNOTAVAIL;
1094 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1095 		       M_WAITOK|M_ZERO);
1096 		sdl->sdl_len = sizeof *sdl;
1097 		sdl->sdl_family = AF_LINK;
1098 		sdl->sdl_index = ifp->if_index;
1099 		sdl->sdl_type = IFT_ETHER;
1100 		sdl->sdl_alen = ETHER_ADDR_LEN;
1101 		e_addr = LLADDR(sdl);
1102 		ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
1103 		*llsa = (struct sockaddr *)sdl;
1104 		return 0;
1105 #endif
1106 #ifdef INET6
1107 	case AF_INET6:
1108 		sin6 = (struct sockaddr_in6 *)sa;
1109 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1110 			/*
1111 			 * An IP6 address of 0 means listen to all
1112 			 * of the Ethernet multicast address used for IP6.
1113 			 * (This is used for multicast routers.)
1114 			 */
1115 			ifp->if_flags |= IFF_ALLMULTI;
1116 			*llsa = 0;
1117 			return 0;
1118 		}
1119 		if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
1120 			return EADDRNOTAVAIL;
1121 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1122 		       M_WAITOK|M_ZERO);
1123 		sdl->sdl_len = sizeof *sdl;
1124 		sdl->sdl_family = AF_LINK;
1125 		sdl->sdl_index = ifp->if_index;
1126 		sdl->sdl_type = IFT_ETHER;
1127 		sdl->sdl_alen = ETHER_ADDR_LEN;
1128 		e_addr = LLADDR(sdl);
1129 		ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
1130 		*llsa = (struct sockaddr *)sdl;
1131 		return 0;
1132 #endif
1133 
1134 	default:
1135 		/*
1136 		 * Well, the text isn't quite right, but it's the name
1137 		 * that counts...
1138 		 */
1139 		return EAFNOSUPPORT;
1140 	}
1141 }
1142