xref: /freebsd/sys/net/if_ethersubr.c (revision 3ff369fed2a08f32dda232c10470b949bef9489f)
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_netgraph.h"
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/random.h>
50 #include <sys/socket.h>
51 #include <sys/sockio.h>
52 #include <sys/sysctl.h>
53 
54 #include <net/if.h>
55 #include <net/netisr.h>
56 #include <net/route.h>
57 #include <net/if_llc.h>
58 #include <net/if_dl.h>
59 #include <net/if_types.h>
60 #include <net/bpf.h>
61 #include <net/ethernet.h>
62 #include <net/bridge.h>
63 
64 #if defined(INET) || defined(INET6)
65 #include <netinet/in.h>
66 #include <netinet/in_var.h>
67 #include <netinet/if_ether.h>
68 #include <netinet/ip_fw.h>
69 #include <netinet/ip_dummynet.h>
70 #endif
71 #ifdef INET6
72 #include <netinet6/nd6.h>
73 #endif
74 
75 #ifdef IPX
76 #include <netipx/ipx.h>
77 #include <netipx/ipx_if.h>
78 int (*ef_inputp)(struct ifnet*, struct ether_header *eh, struct mbuf *m);
79 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp,
80 		struct sockaddr *dst, short *tp, int *hlen);
81 #endif
82 
83 #ifdef NS
84 #include <netns/ns.h>
85 #include <netns/ns_if.h>
86 ushort ns_nettype;
87 int ether_outputdebug = 0;
88 int ether_inputdebug = 0;
89 #endif
90 
91 #ifdef NETATALK
92 #include <netatalk/at.h>
93 #include <netatalk/at_var.h>
94 #include <netatalk/at_extern.h>
95 
96 #define llc_snap_org_code llc_un.type_snap.org_code
97 #define llc_snap_ether_type llc_un.type_snap.ether_type
98 
99 extern u_char	at_org_code[3];
100 extern u_char	aarp_org_code[3];
101 #endif /* NETATALK */
102 
103 /* netgraph node hooks for ng_ether(4) */
104 void	(*ng_ether_input_p)(struct ifnet *ifp,
105 		struct mbuf **mp, struct ether_header *eh);
106 void	(*ng_ether_input_orphan_p)(struct ifnet *ifp,
107 		struct mbuf *m, struct ether_header *eh);
108 int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
109 void	(*ng_ether_attach_p)(struct ifnet *ifp);
110 void	(*ng_ether_detach_p)(struct ifnet *ifp);
111 
112 int	(*vlan_input_p)(struct ether_header *eh, struct mbuf *m);
113 int	(*vlan_input_tag_p)(struct ether_header *eh, struct mbuf *m,
114 		u_int16_t t);
115 
116 /* bridge support */
117 int do_bridge;
118 bridge_in_t *bridge_in_ptr;
119 bdg_forward_t *bdg_forward_ptr;
120 bdgtakeifaces_t *bdgtakeifaces_ptr;
121 struct bdg_softc *ifp2sc;
122 
123 static	int ether_resolvemulti(struct ifnet *, struct sockaddr **,
124 			       struct sockaddr *);
125 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
126 #define senderr(e) do { error = (e); goto bad;} while (0)
127 #define IFP2AC(IFP) ((struct arpcom *)IFP)
128 
129 int
130 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
131 	struct ip_fw **rule, struct ether_header *eh, int shared);
132 static int ether_ipfw;
133 
134 /*
135  * Ethernet output routine.
136  * Encapsulate a packet of type family for the local net.
137  * Use trailer local net encapsulation if enough data in first
138  * packet leaves a multiple of 512 bytes of data in remainder.
139  * Assumes that ifp is actually pointer to arpcom structure.
140  */
141 int
142 ether_output(ifp, m, dst, rt0)
143 	register struct ifnet *ifp;
144 	struct mbuf *m;
145 	struct sockaddr *dst;
146 	struct rtentry *rt0;
147 {
148 	short type;
149 	int error = 0, hdrcmplt = 0;
150  	u_char esrc[6], edst[6];
151 	register struct rtentry *rt;
152 	register struct ether_header *eh;
153 	int off, loop_copy = 0;
154 	int hlen;	/* link layer header lenght */
155 	struct arpcom *ac = IFP2AC(ifp);
156 
157 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
158 		senderr(ENETDOWN);
159 	rt = rt0;
160 	if (rt) {
161 		if ((rt->rt_flags & RTF_UP) == 0) {
162 			rt0 = rt = rtalloc1(dst, 1, 0UL);
163 			if (rt0)
164 				rt->rt_refcnt--;
165 			else
166 				senderr(EHOSTUNREACH);
167 		}
168 		if (rt->rt_flags & RTF_GATEWAY) {
169 			if (rt->rt_gwroute == 0)
170 				goto lookup;
171 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
172 				rtfree(rt); rt = rt0;
173 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1,
174 							  0UL);
175 				if ((rt = rt->rt_gwroute) == 0)
176 					senderr(EHOSTUNREACH);
177 			}
178 		}
179 		if (rt->rt_flags & RTF_REJECT)
180 			if (rt->rt_rmx.rmx_expire == 0 ||
181 			    time_second < rt->rt_rmx.rmx_expire)
182 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
183 	}
184 	hlen = ETHER_HDR_LEN;
185 	switch (dst->sa_family) {
186 #ifdef INET
187 	case AF_INET:
188 		if (!arpresolve(ifp, rt, m, dst, edst, rt0))
189 			return (0);	/* if not yet resolved */
190 		off = m->m_pkthdr.len - m->m_len;
191 		type = htons(ETHERTYPE_IP);
192 		break;
193 #endif
194 #ifdef INET6
195 	case AF_INET6:
196 		if (!nd6_storelladdr(&ac->ac_if, rt, m, dst, (u_char *)edst)) {
197 			/* Something bad happened */
198 			return(0);
199 		}
200 		off = m->m_pkthdr.len - m->m_len;
201 		type = htons(ETHERTYPE_IPV6);
202 		break;
203 #endif
204 #ifdef IPX
205 	case AF_IPX:
206 		if (ef_outputp) {
207 		    error = ef_outputp(ifp, &m, dst, &type, &hlen);
208 		    if (error)
209 			goto bad;
210 		} else
211 		    type = htons(ETHERTYPE_IPX);
212  		bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
213 		    (caddr_t)edst, sizeof (edst));
214 		break;
215 #endif
216 #ifdef NETATALK
217 	case AF_APPLETALK:
218 	  {
219 	    struct at_ifaddr *aa;
220 
221 	    if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) {
222 		    goto bad;
223 	    }
224 	    if (!aarpresolve(ac, m, (struct sockaddr_at *)dst, edst))
225 		    return (0);
226 	    /*
227 	     * In the phase 2 case, need to prepend an mbuf for the llc header.
228 	     * Since we must preserve the value of m, which is passed to us by
229 	     * value, we m_copy() the first mbuf, and use it for our llc header.
230 	     */
231 	    if ( aa->aa_flags & AFA_PHASE2 ) {
232 		struct llc llc;
233 
234 		M_PREPEND(m, sizeof(struct llc), M_TRYWAIT);
235 		llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP;
236 		llc.llc_control = LLC_UI;
237 		bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code));
238 		llc.llc_snap_ether_type = htons( ETHERTYPE_AT );
239 		bcopy(&llc, mtod(m, caddr_t), sizeof(struct llc));
240 		type = htons(m->m_pkthdr.len);
241 		hlen = sizeof(struct llc) + ETHER_HDR_LEN;
242 	    } else {
243 		type = htons(ETHERTYPE_AT);
244 	    }
245 	    break;
246 	  }
247 #endif /* NETATALK */
248 #ifdef NS
249 	case AF_NS:
250 		switch(ns_nettype){
251 		default:
252 		case 0x8137: /* Novell Ethernet_II Ethernet TYPE II */
253 			type = 0x8137;
254 			break;
255 		case 0x0: /* Novell 802.3 */
256 			type = htons( m->m_pkthdr.len);
257 			break;
258 		case 0xe0e0: /* Novell 802.2 and Token-Ring */
259 			M_PREPEND(m, 3, M_TRYWAIT);
260 			type = htons( m->m_pkthdr.len);
261 			cp = mtod(m, u_char *);
262 			*cp++ = 0xE0;
263 			*cp++ = 0xE0;
264 			*cp++ = 0x03;
265 			break;
266 		}
267  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
268 		    (caddr_t)edst, sizeof (edst));
269 		/*
270 		 * XXX if ns_thishost is the same as the node's ethernet
271 		 * address then just the default code will catch this anyhow.
272 		 * So I'm not sure if this next clause should be here at all?
273 		 * [JRE]
274 		 */
275 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst))){
276 			m->m_pkthdr.rcvif = ifp;
277 			inq = &nsintrq;
278 			if (IF_HANDOFF(inq, m, NULL))
279 				schednetisr(NETISR_NS);
280 			return (error);
281 		}
282 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_broadhost, sizeof(edst))){
283 			m->m_flags |= M_BCAST;
284 		}
285 		break;
286 #endif /* NS */
287 
288 	case pseudo_AF_HDRCMPLT:
289 		hdrcmplt = 1;
290 		eh = (struct ether_header *)dst->sa_data;
291 		(void)memcpy(esrc, eh->ether_shost, sizeof (esrc));
292 		/* FALLTHROUGH */
293 
294 	case AF_UNSPEC:
295 		loop_copy = -1; /* if this is for us, don't do it */
296 		eh = (struct ether_header *)dst->sa_data;
297  		(void)memcpy(edst, eh->ether_dhost, sizeof (edst));
298 		type = eh->ether_type;
299 		break;
300 
301 	default:
302 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
303 			dst->sa_family);
304 		senderr(EAFNOSUPPORT);
305 	}
306 
307 	/*
308 	 * Add local net header.  If no space in first mbuf,
309 	 * allocate another.
310 	 */
311 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
312 	if (m == 0)
313 		senderr(ENOBUFS);
314 	eh = mtod(m, struct ether_header *);
315 	(void)memcpy(&eh->ether_type, &type,
316 		sizeof(eh->ether_type));
317  	(void)memcpy(eh->ether_dhost, edst, sizeof (edst));
318 	if (hdrcmplt)
319 		(void)memcpy(eh->ether_shost, esrc,
320 			sizeof(eh->ether_shost));
321 	else
322 		(void)memcpy(eh->ether_shost, ac->ac_enaddr,
323 			sizeof(eh->ether_shost));
324 
325 	/*
326 	 * If a simplex interface, and the packet is being sent to our
327 	 * Ethernet address or a broadcast address, loopback a copy.
328 	 * XXX To make a simplex device behave exactly like a duplex
329 	 * device, we should copy in the case of sending to our own
330 	 * ethernet address (thus letting the original actually appear
331 	 * on the wire). However, we don't do that here for security
332 	 * reasons and compatibility with the original behavior.
333 	 */
334 	if ((ifp->if_flags & IFF_SIMPLEX) && (loop_copy != -1)) {
335 		int csum_flags = 0;
336 
337 		if (m->m_pkthdr.csum_flags & CSUM_IP)
338 			csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
339 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
340 			csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
341 		if ((m->m_flags & M_BCAST) || (loop_copy > 0)) {
342 			struct mbuf *n = m_copy(m, 0, (int)M_COPYALL);
343 
344 			n->m_pkthdr.csum_flags |= csum_flags;
345 			if (csum_flags & CSUM_DATA_VALID)
346 				n->m_pkthdr.csum_data = 0xffff;
347 
348 			(void) if_simloop(ifp, n, dst->sa_family, hlen);
349 		} else if (bcmp(eh->ether_dhost,
350 		    eh->ether_shost, ETHER_ADDR_LEN) == 0) {
351 			m->m_pkthdr.csum_flags |= csum_flags;
352 			if (csum_flags & CSUM_DATA_VALID)
353 				m->m_pkthdr.csum_data = 0xffff;
354 			(void) if_simloop(ifp, m, dst->sa_family, hlen);
355 			return (0);	/* XXX */
356 		}
357 	}
358 
359 	/* Handle ng_ether(4) processing, if any */
360 	if (ng_ether_output_p != NULL) {
361 		if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
362 bad:			if (m != NULL)
363 				m_freem(m);
364 			return (error);
365 		}
366 		if (m == NULL)
367 			return (0);
368 	}
369 
370 	/* Continue with link-layer output */
371 	return ether_output_frame(ifp, m);
372 }
373 
374 /*
375  * Ethernet link layer output routine to send a raw frame to the device.
376  *
377  * This assumes that the 14 byte Ethernet header is present and contiguous
378  * in the first mbuf (if BRIDGE'ing).
379  */
380 int
381 ether_output_frame(ifp, m)
382 	struct ifnet *ifp;
383 	struct mbuf *m;
384 {
385 	int error = 0;
386 
387 #if 1	/* XXX ipfw */
388 	struct ip_fw *rule = NULL;
389 	if (m->m_type == MT_DUMMYNET) { /* extract info from dummynet header */
390 		rule = (struct ip_fw *)(m->m_data) ;
391 		m = m->m_next ;
392 		goto no_bridge;
393 	}
394 #endif
395 	if (BDG_ACTIVE(ifp) ) {
396 		struct ether_header *eh; /* a ptr suffices */
397 
398 		m->m_pkthdr.rcvif = NULL;
399 		eh = mtod(m, struct ether_header *);
400 		m_adj(m, ETHER_HDR_LEN);
401 		m = bdg_forward_ptr(m, eh, ifp);
402 		if (m != NULL)
403 			m_freem(m);
404 		return (0);
405 	}
406 
407 #if 1	/* XXX ipfw */
408 no_bridge:
409 	if (IPFW_LOADED && ether_ipfw != 0) {
410 		struct ether_header save_eh, *eh;
411 
412 		eh = mtod(m, struct ether_header *);
413 		save_eh = *eh;
414 		m_adj(m, ETHER_HDR_LEN);
415 		if (ether_ipfw_chk(&m, ifp, &rule, eh, 0) == 0) {
416 			if (m) {
417 				m_freem(m);
418 				return ENOBUFS;	/* pkt dropped */
419 			} else
420 				return 0;	/* consumed e.g. in a pipe */
421 		}
422 		/* packet was ok, restore the ethernet header */
423 		if ( (void *)(eh + 1) == (void *)m->m_data) {
424 			m->m_data -= ETHER_HDR_LEN ;
425 			m->m_len += ETHER_HDR_LEN ;
426 			m->m_pkthdr.len += ETHER_HDR_LEN ;
427 		} else {
428 			M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
429 			if (m == NULL) /* nope... */
430 			    return ENOBUFS;
431 			bcopy(&save_eh, mtod(m, struct ether_header *),
432 				ETHER_HDR_LEN);
433 		}
434 	}
435 #endif /* XXX ipfw */
436 	/*
437 	 * Queue message on interface, update output statistics if
438 	 * successful, and start output if interface not yet active.
439 	 */
440 	if (! IF_HANDOFF(&ifp->if_snd, m, ifp))
441 		return (ENOBUFS);
442 	return (error);
443 }
444 
445 /*
446  * ipfw processing for ethernet packets (in and out).
447  * The second parameter is NULL from ether_demux, and ifp from
448  * ether_output_frame. This section of code could be used from
449  * bridge.c as well as long as we put some extra field (e.g. shared)
450  * to distinguish that case from ether_output_frame();
451  */
452 int
453 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
454 	struct ip_fw **rule, struct ether_header *eh, int shared)
455 {
456 	struct ether_header save_eh = *eh;	/* could be a ptr in m */
457         int i;
458 
459         if (*rule != NULL) /* dummynet packet, already partially processed */
460             return 1; /* HACK! I should obey the fw_one_pass */
461         /*
462          * i need some amt of data to be contiguous, and in case others need
463          * the packet (shared==1) also better be in the first mbuf.
464          */
465         i = min( (*m0)->m_pkthdr.len, max_protohdr) ;
466         if ( shared || (*m0)->m_len < i) {
467 		*m0 = m_pullup(*m0, i);
468 		if (*m0 == NULL) {
469 			printf("-- bdg: pullup failed.\n") ;
470 			return 0;
471 		}
472         }
473 
474         i = ip_fw_chk_ptr(m0, dst, NULL /* cookie */, rule,
475 	    (struct sockaddr_in **)&save_eh);
476         if ( (i & IP_FW_PORT_DENY_FLAG) || *m0 == NULL) /* drop */
477 		return 0;
478 
479         if (i == 0) /* a PASS rule.  */
480 		return 1;
481 
482         if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG)) {
483 		/*
484 		 * Pass the pkt to dummynet, which consumes it.
485 		 * If shared, make a copy and keep the original.
486 		 * Need to prepend the ethernet header, optimize the common
487 		 * case of eh pointing already into the original mbuf.
488 		 */
489 		struct mbuf *m ;
490 
491 		if (shared) {
492 			m = m_copypacket(*m0, M_DONTWAIT);
493 			if (m == NULL) {
494 				printf("bdg_fwd: copy(1) failed\n");
495 				return 0;
496 			}
497 		} else {
498 			m = *m0 ; /* pass the original to dummynet */
499 			*m0 = NULL ; /* and nothing back to the caller */
500 		}
501 		if ( (void *)(eh + 1) == (void *)m->m_data) {
502 			m->m_data -= ETHER_HDR_LEN ;
503 			m->m_len += ETHER_HDR_LEN ;
504 			m->m_pkthdr.len += ETHER_HDR_LEN ;
505 		} else {
506 			M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
507 			if (m == NULL) /* nope... */
508 				return 0;
509 			bcopy(&save_eh, mtod(m, struct ether_header *),
510 			    ETHER_HDR_LEN);
511 		}
512 		ip_dn_io_ptr((i & 0xffff), dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX,
513 		    m, dst, NULL /*route*/, 0 /*dst*/, *rule, 0 /*flags*/);
514 		return 0;
515         }
516         /*
517          * XXX add divert/forward actions...
518          */
519         /* if none of the above matches, we have to drop the pkt */
520         printf("ether_ipfw: No rules match, so dropping packet!\n");
521         return 0;
522 }
523 
524 /*
525  * Process a received Ethernet packet;
526  * the packet is in the mbuf chain m without
527  * the ether header, which is provided separately.
528  *
529  * NOTA BENE: for many drivers "eh" is a pointer into the first mbuf or
530  * cluster, right before m_data. So be very careful when working on m,
531  * as you could destroy *eh !!
532  * A (probably) more convenient and efficient interface to ether_input
533  * is to have the whole packet (with the ethernet header) into the mbuf:
534  * modules which do not need the ethernet header can easily drop it, while
535  * others (most noticeably bridge and ng_ether) do not need to do additional
536  * work to put the ethernet header back into the mbuf.
537  *
538  * First we perform any link layer operations, then continue
539  * to the upper layers with ether_demux().
540  */
541 void
542 ether_input(ifp, eh, m)
543 	struct ifnet *ifp;
544 	struct ether_header *eh;
545 	struct mbuf *m;
546 {
547 	struct ether_header save_eh;
548 
549 	/* Check for a BPF tap */
550 	if (ifp->if_bpf != NULL) {
551 		struct m_hdr mh;
552 
553 		/* This kludge is OK; BPF treats the "mbuf" as read-only */
554 		mh.mh_next = m;
555 		mh.mh_data = (char *)eh;
556 		mh.mh_len = ETHER_HDR_LEN;
557 		bpf_mtap(ifp, (struct mbuf *)&mh);
558 	}
559 
560 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
561 
562 	/* Handle ng_ether(4) processing, if any */
563 	if (ng_ether_input_p != NULL) {
564 		(*ng_ether_input_p)(ifp, &m, eh);
565 		if (m == NULL)
566 			return;
567 	}
568 
569 	/* Check for bridging mode */
570 	if (BDG_ACTIVE(ifp) ) {
571 		struct ifnet *bif;
572 
573 		/* Check with bridging code */
574 		if ((bif = bridge_in_ptr(ifp, eh)) == BDG_DROP) {
575 			m_freem(m);
576 			return;
577 		}
578 		if (bif != BDG_LOCAL) {
579 			struct mbuf *oldm = m ;
580 
581 			save_eh = *eh ; /* because it might change */
582 			m = bdg_forward_ptr(m, eh, bif); /* needs forwarding */
583 			/*
584 			 * Do not continue if bdg_forward_ptr() processed our
585 			 * packet (and cleared the mbuf pointer m) or if
586 			 * it dropped (m_free'd) the packet itself.
587 			 */
588 			if (m == NULL) {
589 			    if (bif == BDG_BCAST || bif == BDG_MCAST)
590 				printf("bdg_forward drop MULTICAST PKT\n");
591 			    return;
592 			}
593 			if (m != oldm) /* m changed! */
594 			    eh = &save_eh ;
595 		}
596 		if (bif == BDG_LOCAL
597 		    || bif == BDG_BCAST
598 		    || bif == BDG_MCAST)
599 			goto recvLocal;			/* receive locally */
600 
601 		/* If not local and not multicast, just drop it */
602 		if (m != NULL)
603 			m_freem(m);
604 		return;
605        }
606 
607 recvLocal:
608 	/* Continue with upper layer processing */
609 	ether_demux(ifp, eh, m);
610 	/* First chunk of an mbuf contains good junk */
611 	if (harvest.ethernet)
612 		random_harvest(m, 16, 3, 0, RANDOM_NET);
613 }
614 
615 /*
616  * Upper layer processing for a received Ethernet packet.
617  */
618 void
619 ether_demux(ifp, eh, m)
620 	struct ifnet *ifp;
621 	struct ether_header *eh;
622 	struct mbuf *m;
623 {
624 	struct ifqueue *inq;
625 	u_short ether_type;
626 #if defined(NETATALK)
627 	register struct llc *l;
628 #endif
629 
630 #if 1	/* XXX ipfw */
631 	struct ip_fw *rule = NULL;
632 	if (m->m_type == MT_DUMMYNET) { /* extract info from dummynet header */
633 		rule = (struct ip_fw *)(m->m_data) ;
634 		m = m->m_next ;
635 		ifp = m->m_pkthdr.rcvif;
636 		goto post_stats;
637 	}
638 #endif
639 
640     if (! (BDG_ACTIVE(ifp) ) )
641 	/* Discard packet if upper layers shouldn't see it because it was
642 	   unicast to a different Ethernet address. If the driver is working
643 	   properly, then this situation can only happen when the interface
644 	   is in promiscuous mode. */
645 	if ((ifp->if_flags & IFF_PROMISC) != 0
646 	    && (eh->ether_dhost[0] & 1) == 0
647 	    && bcmp(eh->ether_dhost,
648 	      IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN) != 0) {
649 		m_freem(m);
650 		return;
651 	}
652 
653 	/* Discard packet if interface is not up */
654 	if ((ifp->if_flags & IFF_UP) == 0) {
655 		m_freem(m);
656 		return;
657 	}
658 	if (eh->ether_dhost[0] & 1) {
659 		if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
660 			 sizeof(etherbroadcastaddr)) == 0)
661 			m->m_flags |= M_BCAST;
662 		else
663 			m->m_flags |= M_MCAST;
664 	}
665 	if (m->m_flags & (M_BCAST|M_MCAST))
666 		ifp->if_imcasts++;
667 
668 #if 1	/* XXX ipfw */
669 post_stats:
670 	if ( IPFW_LOADED && ether_ipfw != 0) {
671 		if (ether_ipfw_chk(&m, NULL, &rule, eh, 0 ) == 0) {
672 			if (m)
673 				m_freem(m);
674 			return;
675 		}
676 	}
677 #endif /* XXX ipfw */
678 
679 	ether_type = ntohs(eh->ether_type);
680 
681 	switch (ether_type) {
682 #ifdef INET
683 	case ETHERTYPE_IP:
684 		if (ipflow_fastforward(m))
685 			return;
686 		schednetisr(NETISR_IP);
687 		inq = &ipintrq;
688 		break;
689 
690 	case ETHERTYPE_ARP:
691 		if (ifp->if_flags & IFF_NOARP) {
692 			/* Discard packet if ARP is disabled on interface */
693 			m_freem(m);
694 			return;
695 		}
696 		schednetisr(NETISR_ARP);
697 		inq = &arpintrq;
698 		break;
699 #endif
700 #ifdef IPX
701 	case ETHERTYPE_IPX:
702 		if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
703 			return;
704 		schednetisr(NETISR_IPX);
705 		inq = &ipxintrq;
706 		break;
707 #endif
708 #ifdef INET6
709 	case ETHERTYPE_IPV6:
710 		schednetisr(NETISR_IPV6);
711 		inq = &ip6intrq;
712 		break;
713 #endif
714 #ifdef NS
715 	case 0x8137: /* Novell Ethernet_II Ethernet TYPE II */
716 		schednetisr(NETISR_NS);
717 		inq = &nsintrq;
718 		break;
719 
720 #endif /* NS */
721 #ifdef NETATALK
722         case ETHERTYPE_AT:
723                 schednetisr(NETISR_ATALK);
724                 inq = &atintrq1;
725                 break;
726         case ETHERTYPE_AARP:
727 		/* probably this should be done with a NETISR as well */
728                 aarpinput(IFP2AC(ifp), m); /* XXX */
729                 return;
730 #endif /* NETATALK */
731 	case ETHERTYPE_VLAN:
732 		/* XXX lock ? */
733 		if (vlan_input_p != NULL)
734 			(*vlan_input_p)(eh, m);
735 		else {
736 			m->m_pkthdr.rcvif->if_noproto++;
737 			m_freem(m);
738 		}
739 		/* XXX unlock ? */
740 		return;
741 	default:
742 #ifdef IPX
743 		if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
744 			return;
745 #endif /* IPX */
746 #ifdef NS
747 		checksum = mtod(m, ushort *);
748 		/* Novell 802.3 */
749 		if ((ether_type <= ETHERMTU) &&
750 			((*checksum == 0xffff) || (*checksum == 0xE0E0))){
751 			if(*checksum == 0xE0E0) {
752 				m->m_pkthdr.len -= 3;
753 				m->m_len -= 3;
754 				m->m_data += 3;
755 			}
756 				schednetisr(NETISR_NS);
757 				inq = &nsintrq;
758 				break;
759 		}
760 #endif /* NS */
761 #if defined(NETATALK)
762 		if (ether_type > ETHERMTU)
763 			goto dropanyway;
764 		l = mtod(m, struct llc *);
765 		switch (l->llc_dsap) {
766 		case LLC_SNAP_LSAP:
767 		    switch (l->llc_control) {
768 		    case LLC_UI:
769 			if (l->llc_ssap != LLC_SNAP_LSAP)
770 			    goto dropanyway;
771 
772 			if (Bcmp(&(l->llc_snap_org_code)[0], at_org_code,
773 				   sizeof(at_org_code)) == 0 &&
774 			     ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
775 			    inq = &atintrq2;
776 			    m_adj( m, sizeof( struct llc ));
777 			    schednetisr(NETISR_ATALK);
778 			    break;
779 			}
780 
781 			if (Bcmp(&(l->llc_snap_org_code)[0], aarp_org_code,
782 				   sizeof(aarp_org_code)) == 0 &&
783 			     ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) {
784 			    m_adj( m, sizeof( struct llc ));
785 			    aarpinput(IFP2AC(ifp), m); /* XXX */
786 			    return;
787 			}
788 
789 		    default:
790 			goto dropanyway;
791 		    }
792 		    break;
793 		dropanyway:
794 		default:
795 			if (ng_ether_input_orphan_p != NULL)
796 				(*ng_ether_input_orphan_p)(ifp, m, eh);
797 			else
798 				m_freem(m);
799 			return;
800 		}
801 #else /* NETATALK */
802 		if (ng_ether_input_orphan_p != NULL)
803 			(*ng_ether_input_orphan_p)(ifp, m, eh);
804 		else
805 			m_freem(m);
806 		return;
807 #endif /* NETATALK */
808 	}
809 
810 	(void) IF_HANDOFF(inq, m, NULL);
811 }
812 
813 /*
814  * Perform common duties while attaching to interface list
815  */
816 void
817 ether_ifattach(ifp, bpf)
818 	register struct ifnet *ifp;
819 	int bpf;
820 {
821 	register struct ifaddr *ifa;
822 	register struct sockaddr_dl *sdl;
823 
824 	ifp->if_type = IFT_ETHER;
825 	ifp->if_addrlen = 6;
826 	ifp->if_hdrlen = 14;
827 	if_attach(ifp);
828 	ifp->if_mtu = ETHERMTU;
829 	ifp->if_resolvemulti = ether_resolvemulti;
830 	if (ifp->if_baudrate == 0)
831 	    ifp->if_baudrate = 10000000;
832 	ifp->if_broadcastaddr = etherbroadcastaddr;
833 	ifa = ifaddr_byindex(ifp->if_index);
834 	KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
835 	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
836 	sdl->sdl_type = IFT_ETHER;
837 	sdl->sdl_alen = ifp->if_addrlen;
838 	bcopy((IFP2AC(ifp))->ac_enaddr, LLADDR(sdl), ifp->if_addrlen);
839 	if (bpf)
840 		bpfattach(ifp, DLT_EN10MB, sizeof(struct ether_header));
841 	if (ng_ether_attach_p != NULL)
842 		(*ng_ether_attach_p)(ifp);
843 	if (BDG_LOADED)
844 		bdgtakeifaces_ptr();
845 }
846 
847 /*
848  * Perform common duties while detaching an Ethernet interface
849  */
850 void
851 ether_ifdetach(ifp, bpf)
852 	struct ifnet *ifp;
853 	int bpf;
854 {
855 	if (ng_ether_detach_p != NULL)
856 		(*ng_ether_detach_p)(ifp);
857 	if (bpf)
858 		bpfdetach(ifp);
859 	if_detach(ifp);
860 	if (BDG_LOADED)
861 		bdgtakeifaces_ptr();
862 }
863 
864 SYSCTL_DECL(_net_link);
865 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
866 SYSCTL_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW,
867             &ether_ipfw,0,"Pass ether pkts through firewall");
868 
869 int
870 ether_ioctl(ifp, command, data)
871 	struct ifnet *ifp;
872 	int command;
873 	caddr_t data;
874 {
875 	struct ifaddr *ifa = (struct ifaddr *) data;
876 	struct ifreq *ifr = (struct ifreq *) data;
877 	int error = 0;
878 
879 	switch (command) {
880 	case SIOCSIFADDR:
881 		ifp->if_flags |= IFF_UP;
882 
883 		switch (ifa->ifa_addr->sa_family) {
884 #ifdef INET
885 		case AF_INET:
886 			ifp->if_init(ifp->if_softc);	/* before arpwhohas */
887 			arp_ifinit(ifp, ifa);
888 			break;
889 #endif
890 #ifdef IPX
891 		/*
892 		 * XXX - This code is probably wrong
893 		 */
894 		case AF_IPX:
895 			{
896 			register struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr);
897 			struct arpcom *ac = IFP2AC(ifp);
898 
899 			if (ipx_nullhost(*ina))
900 				ina->x_host =
901 				    *(union ipx_host *)
902 			            ac->ac_enaddr;
903 			else {
904 				bcopy((caddr_t) ina->x_host.c_host,
905 				      (caddr_t) ac->ac_enaddr,
906 				      sizeof(ac->ac_enaddr));
907 			}
908 
909 			/*
910 			 * Set new address
911 			 */
912 			ifp->if_init(ifp->if_softc);
913 			break;
914 			}
915 #endif
916 #ifdef NS
917 		/*
918 		 * XXX - This code is probably wrong
919 		 */
920 		case AF_NS:
921 		{
922 			register struct ns_addr *ina = &(IA_SNS(ifa)->sns_addr);
923 			struct arpcom *ac = IFP2AC(ifp);
924 
925 			if (ns_nullhost(*ina))
926 				ina->x_host =
927 				    *(union ns_host *) (ac->ac_enaddr);
928 			else {
929 				bcopy((caddr_t) ina->x_host.c_host,
930 				      (caddr_t) ac->ac_enaddr,
931 				      sizeof(ac->ac_enaddr));
932 			}
933 
934 			/*
935 			 * Set new address
936 			 */
937 			ifp->if_init(ifp->if_softc);
938 			break;
939 		}
940 #endif
941 		default:
942 			ifp->if_init(ifp->if_softc);
943 			break;
944 		}
945 		break;
946 
947 	case SIOCGIFADDR:
948 		{
949 			struct sockaddr *sa;
950 
951 			sa = (struct sockaddr *) & ifr->ifr_data;
952 			bcopy(IFP2AC(ifp)->ac_enaddr,
953 			      (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
954 		}
955 		break;
956 
957 	case SIOCSIFMTU:
958 		/*
959 		 * Set the interface MTU.
960 		 */
961 		if (ifr->ifr_mtu > ETHERMTU) {
962 			error = EINVAL;
963 		} else {
964 			ifp->if_mtu = ifr->ifr_mtu;
965 		}
966 		break;
967 	}
968 	return (error);
969 }
970 
971 int
972 ether_resolvemulti(ifp, llsa, sa)
973 	struct ifnet *ifp;
974 	struct sockaddr **llsa;
975 	struct sockaddr *sa;
976 {
977 	struct sockaddr_dl *sdl;
978 	struct sockaddr_in *sin;
979 #ifdef INET6
980 	struct sockaddr_in6 *sin6;
981 #endif
982 	u_char *e_addr;
983 
984 	switch(sa->sa_family) {
985 	case AF_LINK:
986 		/*
987 		 * No mapping needed. Just check that it's a valid MC address.
988 		 */
989 		sdl = (struct sockaddr_dl *)sa;
990 		e_addr = LLADDR(sdl);
991 		if ((e_addr[0] & 1) != 1)
992 			return EADDRNOTAVAIL;
993 		*llsa = 0;
994 		return 0;
995 
996 #ifdef INET
997 	case AF_INET:
998 		sin = (struct sockaddr_in *)sa;
999 		if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
1000 			return EADDRNOTAVAIL;
1001 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1002 		       M_WAITOK|M_ZERO);
1003 		sdl->sdl_len = sizeof *sdl;
1004 		sdl->sdl_family = AF_LINK;
1005 		sdl->sdl_index = ifp->if_index;
1006 		sdl->sdl_type = IFT_ETHER;
1007 		sdl->sdl_alen = ETHER_ADDR_LEN;
1008 		e_addr = LLADDR(sdl);
1009 		ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
1010 		*llsa = (struct sockaddr *)sdl;
1011 		return 0;
1012 #endif
1013 #ifdef INET6
1014 	case AF_INET6:
1015 		sin6 = (struct sockaddr_in6 *)sa;
1016 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1017 			/*
1018 			 * An IP6 address of 0 means listen to all
1019 			 * of the Ethernet multicast address used for IP6.
1020 			 * (This is used for multicast routers.)
1021 			 */
1022 			ifp->if_flags |= IFF_ALLMULTI;
1023 			*llsa = 0;
1024 			return 0;
1025 		}
1026 		if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
1027 			return EADDRNOTAVAIL;
1028 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1029 		       M_WAITOK|M_ZERO);
1030 		sdl->sdl_len = sizeof *sdl;
1031 		sdl->sdl_family = AF_LINK;
1032 		sdl->sdl_index = ifp->if_index;
1033 		sdl->sdl_type = IFT_ETHER;
1034 		sdl->sdl_alen = ETHER_ADDR_LEN;
1035 		e_addr = LLADDR(sdl);
1036 		ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
1037 		*llsa = (struct sockaddr *)sdl;
1038 		return 0;
1039 #endif
1040 
1041 	default:
1042 		/*
1043 		 * Well, the text isn't quite right, but it's the name
1044 		 * that counts...
1045 		 */
1046 		return EAFNOSUPPORT;
1047 	}
1048 }
1049 
1050