xref: /dragonfly/sys/net/if_ethersubr.c (revision 8e9b4bd4)
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: src/sys/net/if_ethersubr.c,v 1.70.2.33 2003/04/28 15:45:53 archie Exp $
35  * $DragonFly: src/sys/net/if_ethersubr.c,v 1.50 2007/10/25 13:13:18 sephe Exp $
36  */
37 
38 #include "opt_atalk.h"
39 #include "opt_inet.h"
40 #include "opt_inet6.h"
41 #include "opt_ipx.h"
42 #include "opt_netgraph.h"
43 #include "opt_carp.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.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/ifq_var.h>
61 #include <net/bpf.h>
62 #include <net/ethernet.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 <net/ipfw/ip_fw.h>
69 #include <net/dummynet/ip_dummynet.h>
70 #endif
71 #ifdef INET6
72 #include <netinet6/nd6.h>
73 #endif
74 
75 #ifdef CARP
76 #include <netinet/ip_carp.h>
77 #endif
78 
79 #ifdef IPX
80 #include <netproto/ipx/ipx.h>
81 #include <netproto/ipx/ipx_if.h>
82 int (*ef_inputp)(struct ifnet*, const struct ether_header *eh, struct mbuf *m);
83 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp, struct sockaddr *dst,
84 		  short *tp, int *hlen);
85 #endif
86 
87 #ifdef NS
88 #include <netns/ns.h>
89 #include <netns/ns_if.h>
90 ushort ns_nettype;
91 int ether_outputdebug = 0;
92 int ether_inputdebug = 0;
93 #endif
94 
95 #ifdef NETATALK
96 #include <netproto/atalk/at.h>
97 #include <netproto/atalk/at_var.h>
98 #include <netproto/atalk/at_extern.h>
99 
100 #define	llc_snap_org_code	llc_un.type_snap.org_code
101 #define	llc_snap_ether_type	llc_un.type_snap.ether_type
102 
103 extern u_char	at_org_code[3];
104 extern u_char	aarp_org_code[3];
105 #endif /* NETATALK */
106 
107 /* netgraph node hooks for ng_ether(4) */
108 void	(*ng_ether_input_p)(struct ifnet *ifp,
109 		struct mbuf **mp, const struct ether_header *eh);
110 void	(*ng_ether_input_orphan_p)(struct ifnet *ifp,
111 		struct mbuf *m, const struct ether_header *eh);
112 int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
113 void	(*ng_ether_attach_p)(struct ifnet *ifp);
114 void	(*ng_ether_detach_p)(struct ifnet *ifp);
115 
116 int	(*vlan_input_p)(const struct ether_header *eh, struct mbuf *m);
117 int	(*vlan_input_tag_p)(struct mbuf *m, uint16_t t);
118 
119 static int ether_output(struct ifnet *, struct mbuf *, struct sockaddr *,
120 			struct rtentry *);
121 
122 /*
123  * if_bridge support
124  */
125 struct mbuf *(*bridge_input_p)(struct ifnet *, struct mbuf *);
126 int (*bridge_output_p)(struct ifnet *, struct mbuf *,
127 		       struct sockaddr *, struct rtentry *);
128 void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
129 
130 static int ether_resolvemulti(struct ifnet *, struct sockaddr **,
131 			      struct sockaddr *);
132 
133 const uint8_t etherbroadcastaddr[ETHER_ADDR_LEN] = {
134 	0xff, 0xff, 0xff, 0xff, 0xff, 0xff
135 };
136 
137 #define gotoerr(e) do { error = (e); goto bad; } while (0)
138 #define IFP2AC(ifp) ((struct arpcom *)(ifp))
139 
140 static boolean_t ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
141 				struct ip_fw **rule,
142 				const struct ether_header *eh,
143 				boolean_t shared);
144 
145 static int ether_ipfw;
146 SYSCTL_DECL(_net_link);
147 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
148 SYSCTL_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW,
149 	   &ether_ipfw, 0, "Pass ether pkts through firewall");
150 
151 /*
152  * Ethernet output routine.
153  * Encapsulate a packet of type family for the local net.
154  * Use trailer local net encapsulation if enough data in first
155  * packet leaves a multiple of 512 bytes of data in remainder.
156  * Assumes that ifp is actually pointer to arpcom structure.
157  */
158 static int
159 ether_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
160 	     struct rtentry *rt)
161 {
162 	struct ether_header *eh, *deh;
163 	u_char *edst;
164 	int loop_copy = 0;
165 	int hlen = ETHER_HDR_LEN;	/* link layer header length */
166 	struct arpcom *ac = IFP2AC(ifp);
167 	int error;
168 
169 	ASSERT_SERIALIZED(ifp->if_serializer);
170 
171 	if (ifp->if_flags & IFF_MONITOR)
172 		gotoerr(ENETDOWN);
173 	if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
174 		gotoerr(ENETDOWN);
175 
176 	M_PREPEND(m, sizeof(struct ether_header), MB_DONTWAIT);
177 	if (m == NULL)
178 		return (ENOBUFS);
179 	eh = mtod(m, struct ether_header *);
180 	edst = eh->ether_dhost;
181 
182 	/*
183 	 * Fill in the destination ethernet address and frame type.
184 	 */
185 	switch (dst->sa_family) {
186 #ifdef INET
187 	case AF_INET:
188 		if (!arpresolve(ifp, rt, m, dst, edst))
189 			return (0);	/* if not yet resolved */
190 		eh->ether_type = htons(ETHERTYPE_IP);
191 		break;
192 #endif
193 #ifdef INET6
194 	case AF_INET6:
195 		if (!nd6_storelladdr(&ac->ac_if, rt, m, dst, edst))
196 			return (0);		/* Something bad happenned. */
197 		eh->ether_type = htons(ETHERTYPE_IPV6);
198 		break;
199 #endif
200 #ifdef IPX
201 	case AF_IPX:
202 		if (ef_outputp != NULL) {
203 			error = ef_outputp(ifp, &m, dst, &eh->ether_type,
204 					   &hlen);
205 			if (error)
206 				goto bad;
207 		} else {
208 			eh->ether_type = htons(ETHERTYPE_IPX);
209 			bcopy(&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
210 			      edst, ETHER_ADDR_LEN);
211 		}
212 		break;
213 #endif
214 #ifdef NETATALK
215 	case AF_APPLETALK: {
216 		struct at_ifaddr *aa;
217 
218 		if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) {
219 			error = 0;	/* XXX */
220 			goto bad;
221 		}
222 		/*
223 		 * In the phase 2 case, need to prepend an mbuf for
224 		 * the llc header.  Since we must preserve the value
225 		 * of m, which is passed to us by value, we m_copy()
226 		 * the first mbuf, and use it for our llc header.
227 		 */
228 		if (aa->aa_flags & AFA_PHASE2) {
229 			struct llc llc;
230 
231 			M_PREPEND(m, sizeof(struct llc), MB_DONTWAIT);
232 			eh = mtod(m, struct ether_header *);
233 			edst = eh->ether_dhost;
234 			llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP;
235 			llc.llc_control = LLC_UI;
236 			bcopy(at_org_code, llc.llc_snap_org_code,
237 			      sizeof at_org_code);
238 			llc.llc_snap_ether_type = htons(ETHERTYPE_AT);
239 			bcopy(&llc,
240 			      mtod(m, caddr_t) + sizeof(struct ether_header),
241 			      sizeof(struct llc));
242 			eh->ether_type = htons(m->m_pkthdr.len);
243 			hlen = sizeof(struct llc) + ETHER_HDR_LEN;
244 		} else {
245 			eh->ether_type = htons(ETHERTYPE_AT);
246 		}
247 		if (!aarpresolve(ac, m, (struct sockaddr_at *)dst, edst))
248 			return (0);
249 		break;
250 	  }
251 #endif
252 #ifdef NS
253 	case AF_NS:
254 		switch(ns_nettype) {
255 		default:
256 		case 0x8137:	/* Novell Ethernet_II Ethernet TYPE II */
257 			eh->ether_type = 0x8137;
258 			break;
259 		case 0x0:	/* Novell 802.3 */
260 			eh->ether_type = htons(m->m_pkthdr.len);
261 			break;
262 		case 0xe0e0:	/* Novell 802.2 and Token-Ring */
263 			M_PREPEND(m, 3, MB_DONTWAIT);
264 			eh = mtod(m, struct ether_header *);
265 			edst = eh->ether_dhost;
266 			eh->ether_type = htons(m->m_pkthdr.len);
267 			cp = mtod(m, u_char *) + sizeof(struct ether_header);
268 			*cp++ = 0xE0;
269 			*cp++ = 0xE0;
270 			*cp++ = 0x03;
271 			break;
272 		}
273 		bcopy(&(((struct sockaddr_ns *)dst)->sns_addr.x_host), edst,
274 		      ETHER_ADDR_LEN);
275 		/*
276 		 * XXX if ns_thishost is the same as the node's ethernet
277 		 * address then just the default code will catch this anyhow.
278 		 * So I'm not sure if this next clause should be here at all?
279 		 * [JRE]
280 		 */
281 		if (bcmp(edst, &ns_thishost, ETHER_ADDR_LEN) == 0) {
282 			m->m_pkthdr.rcvif = ifp;
283 			netisr_dispatch(NETISR_NS, m);
284 			return (error);
285 		}
286 		if (bcmp(edst, &ns_broadhost, ETHER_ADDR_LEN) == 0)
287 			m->m_flags |= M_BCAST;
288 		break;
289 #endif
290 	case pseudo_AF_HDRCMPLT:
291 	case AF_UNSPEC:
292 		loop_copy = -1; /* if this is for us, don't do it */
293 		deh = (struct ether_header *)dst->sa_data;
294 		memcpy(edst, deh->ether_dhost, ETHER_ADDR_LEN);
295 		eh->ether_type = deh->ether_type;
296 		break;
297 
298 	default:
299 		if_printf(ifp, "can't handle af%d\n", dst->sa_family);
300 		gotoerr(EAFNOSUPPORT);
301 	}
302 
303 	if (dst->sa_family == pseudo_AF_HDRCMPLT)	/* unlikely */
304 		memcpy(eh->ether_shost,
305 		       ((struct ether_header *)dst->sa_data)->ether_shost,
306 		       ETHER_ADDR_LEN);
307 	else
308 		memcpy(eh->ether_shost, ac->ac_enaddr, ETHER_ADDR_LEN);
309 
310 	/*
311 	 * Bridges require special output handling.
312 	 */
313 	if (ifp->if_bridge) {
314 		KASSERT(bridge_output_p != NULL,
315 			("%s: if_bridge not loaded!", __func__));
316 		return ((*bridge_output_p)(ifp, m, NULL, NULL));
317 	}
318 
319 	/*
320 	 * If a simplex interface, and the packet is being sent to our
321 	 * Ethernet address or a broadcast address, loopback a copy.
322 	 * XXX To make a simplex device behave exactly like a duplex
323 	 * device, we should copy in the case of sending to our own
324 	 * ethernet address (thus letting the original actually appear
325 	 * on the wire). However, we don't do that here for security
326 	 * reasons and compatibility with the original behavior.
327 	 */
328 	if ((ifp->if_flags & IFF_SIMPLEX) && (loop_copy != -1)) {
329 		int csum_flags = 0;
330 
331 		if (m->m_pkthdr.csum_flags & CSUM_IP)
332 			csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID);
333 		if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
334 			csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
335 		if ((m->m_flags & M_BCAST) || (loop_copy > 0)) {
336 			struct mbuf *n;
337 
338 			if ((n = m_copypacket(m, MB_DONTWAIT)) != NULL) {
339 				n->m_pkthdr.csum_flags |= csum_flags;
340 				if (csum_flags & CSUM_DATA_VALID)
341 					n->m_pkthdr.csum_data = 0xffff;
342 				if_simloop(ifp, n, dst->sa_family, hlen);
343 			} else
344 				ifp->if_iqdrops++;
345 		} else if (bcmp(eh->ether_dhost, eh->ether_shost,
346 				ETHER_ADDR_LEN) == 0) {
347 			m->m_pkthdr.csum_flags |= csum_flags;
348 			if (csum_flags & CSUM_DATA_VALID)
349 				m->m_pkthdr.csum_data = 0xffff;
350 			if_simloop(ifp, m, dst->sa_family, hlen);
351 			return (0);	/* XXX */
352 		}
353 	}
354 
355 #ifdef CARP
356 	if (ifp->if_carp && (error = carp_output(ifp, m, dst, NULL)))
357 		goto bad;
358 #endif
359 
360 
361 	/* Handle ng_ether(4) processing, if any */
362 	if (ng_ether_output_p != NULL) {
363 		if ((error = (*ng_ether_output_p)(ifp, &m)) != 0)
364 			goto bad;
365 		if (m == NULL)
366 			return (0);
367 	}
368 
369 	/* Continue with link-layer output */
370 	return ether_output_frame(ifp, m);
371 
372 bad:
373 	m_freem(m);
374 	return (error);
375 }
376 
377 /*
378  * Ethernet link layer output routine to send a raw frame to the device.
379  *
380  * This assumes that the 14 byte Ethernet header is present and contiguous
381  * in the first mbuf.
382  */
383 int
384 ether_output_frame(struct ifnet *ifp, struct mbuf *m)
385 {
386 	struct ip_fw *rule = NULL;
387 	int error = 0;
388 	struct altq_pktattr pktattr;
389 	struct m_tag *mtag;
390 
391 	ASSERT_SERIALIZED(ifp->if_serializer);
392 
393 	/* Extract info from dummynet tag */
394 	mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
395 	if (mtag != NULL) {
396 		rule = ((struct dn_pkt *)m_tag_data(mtag))->rule;
397 
398 		m_tag_delete(m, mtag);
399 		mtag = NULL;
400 	}
401 
402 	if (ifq_is_enabled(&ifp->if_snd))
403 		altq_etherclassify(&ifp->if_snd, m, &pktattr);
404 	crit_enter();
405 	if (IPFW_LOADED && ether_ipfw != 0) {
406 		struct ether_header save_eh, *eh;
407 
408 		eh = mtod(m, struct ether_header *);
409 		save_eh = *eh;
410 		m_adj(m, ETHER_HDR_LEN);
411 		if (!ether_ipfw_chk(&m, ifp, &rule, eh, FALSE)) {
412 			crit_exit();
413 			if (m != NULL) {
414 				m_freem(m);
415 				return ENOBUFS; /* pkt dropped */
416 			} else
417 				return 0;	/* consumed e.g. in a pipe */
418 		}
419 		eh = mtod(m, struct ether_header *);
420 		/* packet was ok, restore the ethernet header */
421 		if ((void *)(eh + 1) == (void *)m->m_data) {
422 			m->m_data -= ETHER_HDR_LEN ;
423 			m->m_len += ETHER_HDR_LEN ;
424 			m->m_pkthdr.len += ETHER_HDR_LEN ;
425 		} else {
426 			M_PREPEND(m, ETHER_HDR_LEN, MB_DONTWAIT);
427 			if (m == NULL) /* nope... */ {
428 				crit_exit();
429 				return ENOBUFS;
430 			}
431 			bcopy(&save_eh, mtod(m, struct ether_header *),
432 			      ETHER_HDR_LEN);
433 		}
434 	}
435 	crit_exit();
436 
437 	/*
438 	 * Queue message on interface, update output statistics if
439 	 * successful, and start output if interface not yet active.
440 	 */
441 	error = ifq_handoff(ifp, m, &pktattr);
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().
449  */
450 static boolean_t
451 ether_ipfw_chk(
452 	struct mbuf **m0,
453 	struct ifnet *dst,
454 	struct ip_fw **rule,
455 	const struct ether_header *eh,
456 	boolean_t shared)
457 {
458 	struct ether_header save_eh = *eh;	/* might be a ptr in m */
459 	struct ip_fw_args args;
460 	struct m_tag *mtag;
461 	int i;
462 
463 	if (*rule != NULL && fw_one_pass)
464 		return TRUE; /* dummynet packet, already partially processed */
465 
466 	/*
467 	 * I need some amount of data to be contiguous, and in case others
468 	 * need the packet (shared==TRUE), it also better be in the first mbuf.
469 	 */
470 	i = min((*m0)->m_pkthdr.len, max_protohdr);
471 	if (shared || (*m0)->m_len < i) {
472 		*m0 = m_pullup(*m0, i);
473 		if (*m0 == NULL)
474 			return FALSE;
475 	}
476 
477 	args.m = *m0;		/* the packet we are looking at		*/
478 	args.oif = dst;		/* destination, if any			*/
479 	if ((mtag = m_tag_find(*m0, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL)
480 		m_tag_delete(*m0, mtag);
481 	args.rule = *rule;	/* matching rule to restart		*/
482 	args.next_hop = NULL;	/* we do not support forward yet	*/
483 	args.eh = &save_eh;	/* MAC header for bridged/MAC packets	*/
484 	i = ip_fw_chk_ptr(&args);
485 	*m0 = args.m;
486 	*rule = args.rule;
487 
488 	if ((i & IP_FW_PORT_DENY_FLAG) || *m0 == NULL)	/* drop */
489 		return FALSE;
490 
491 	if (i == 0)					/* a PASS rule.  */
492 		return TRUE;
493 
494 	if (DUMMYNET_LOADED && (i & IP_FW_PORT_DYNT_FLAG)) {
495 		/*
496 		 * Pass the pkt to dummynet, which consumes it.
497 		 * If shared, make a copy and keep the original.
498 		 */
499 		struct mbuf *m ;
500 
501 		if (shared) {
502 			m = m_copypacket(*m0, MB_DONTWAIT);
503 			if (m == NULL)
504 				return FALSE;
505 		} else {
506 			m = *m0 ;	/* pass the original to dummynet */
507 			*m0 = NULL ;	/* and nothing back to the caller */
508 		}
509 		/*
510 		 * Prepend the header, optimize for the common case of
511 		 * eh pointing into the mbuf.
512 		 */
513 		if ((const void *)(eh + 1) == (void *)m->m_data) {
514 			m->m_data -= ETHER_HDR_LEN ;
515 			m->m_len += ETHER_HDR_LEN ;
516 			m->m_pkthdr.len += ETHER_HDR_LEN ;
517 		} else {
518 			M_PREPEND(m, ETHER_HDR_LEN, MB_DONTWAIT);
519 			if (m == NULL)
520 				return FALSE;
521 			bcopy(&save_eh, mtod(m, struct ether_header *),
522 			      ETHER_HDR_LEN);
523 		}
524 		ip_dn_io_ptr(m, (i & 0xffff),
525 			     dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX, &args);
526 		return FALSE;
527 	}
528 	/*
529 	 * XXX at some point add support for divert/forward actions.
530 	 * If none of the above matches, we have to drop the pkt.
531 	 */
532 	return FALSE;
533 }
534 
535 /*
536  * Process a received Ethernet packet.
537  *
538  * The ethernet header is assumed to be in the mbuf so the caller
539  * MUST MAKE SURE that there are at least sizeof(struct ether_header)
540  * bytes in the first mbuf.
541  *
542  * This allows us to concentrate in one place a bunch of code which
543  * is replicated in all device drivers. Also, many functions called
544  * from ether_input() try to put the eh back into the mbuf, so we
545  * can later propagate the 'contiguous packet' interface to them.
546  *
547  * NOTA BENE: for all drivers "eh" is a pointer into the first mbuf or
548  * cluster, right before m_data. So be very careful when working on m,
549  * as you could destroy *eh !!
550  *
551  * First we perform any link layer operations, then continue to the
552  * upper layers with ether_demux().
553  */
554 void
555 ether_input(struct ifnet *ifp, struct mbuf *m)
556 {
557 	struct ether_header *eh;
558 
559 	ASSERT_SERIALIZED(ifp->if_serializer);
560 
561 	if (m->m_len < sizeof(struct ether_header)) {
562 		/* XXX error in the caller. */
563 		m_freem(m);
564 		return;
565 	}
566 	m->m_pkthdr.rcvif = ifp;
567 
568 	BPF_MTAP(ifp, m);
569 
570 	ifp->if_ibytes += m->m_pkthdr.len;
571 
572 	if (ifp->if_flags & IFF_MONITOR) {
573 		/*
574 		 * Interface marked for monitoring; discard packet.
575 		 */
576 		 m_freem(m);
577 		 return;
578 	}
579 
580 	/*
581 	 * Tap the packet off here for a bridge.  bridge_input()
582 	 * will return NULL if it has consumed the packet, otherwise
583 	 * it gets processed as normal.  Note that bridge_input()
584 	 * will always return the original packet if we need to
585 	 * process it locally.
586 	 */
587 	if (ifp->if_bridge) {
588 		KASSERT(bridge_input_p != NULL,
589 			("%s: if_bridge not loaded!", __func__));
590 
591 		if(m->m_flags & M_PROTO1) {
592 			m->m_flags &= ~M_PROTO1;
593 		} else {
594 			/* clear M_PROMISC, in case the packets comes from a vlan */
595 			/* m->m_flags &= ~M_PROMISC; */
596 			lwkt_serialize_exit(ifp->if_serializer);
597 			m = (*bridge_input_p)(ifp, m);
598 			lwkt_serialize_enter(ifp->if_serializer);
599 			if (m == NULL)
600 				return;
601 
602 			KASSERT(ifp == m->m_pkthdr.rcvif,
603 				("bridge_input_p changed rcvif\n"));
604 		}
605 	}
606 
607 	eh = mtod(m, struct ether_header *);
608 
609 	/* XXX old crufty stuff, needs to be removed */
610 	m_adj(m, sizeof(struct ether_header));
611 	/* XXX */
612 	/* m->m_pkthdr.len = m->m_len; */
613 
614 	/* Handle ng_ether(4) processing, if any */
615 	if (ng_ether_input_p != NULL) {
616 		lwkt_serialize_exit(ifp->if_serializer);
617 		(*ng_ether_input_p)(ifp, &m, eh);
618 		lwkt_serialize_enter(ifp->if_serializer);
619 		if (m == NULL)
620 			return;
621 	}
622 
623 	/* Continue with upper layer processing */
624 	ether_demux(ifp, eh, m);
625 }
626 
627 /*
628  * Upper layer processing for a received Ethernet packet.
629  */
630 void
631 ether_demux(struct ifnet *ifp, struct ether_header *eh0, struct mbuf *m)
632 {
633 	struct ether_header eh;
634 	int isr;
635 	u_short ether_type;
636 	struct ip_fw *rule = NULL;
637 	struct m_tag *mtag;
638 #ifdef NETATALK
639 	struct llc *l;
640 #endif
641 
642 	eh = *eh0;
643 
644 	/* Extract info from dummynet tag */
645 	mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
646 	if (mtag != NULL) {
647 		rule = ((struct dn_pkt *)m_tag_data(mtag))->rule;
648 		KKASSERT(ifp == NULL);
649 		ifp = m->m_pkthdr.rcvif;
650 
651 		m_tag_delete(m, mtag);
652 		mtag = NULL;
653 	}
654 	if (rule)	/* packet is passing the second time */
655 		goto post_stats;
656 
657 #ifdef CARP
658 	/*
659          * XXX: Okay, we need to call carp_forus() and - if it is for
660          * us jump over code that does the normal check
661          * "ac_enaddr == ether_dhost". The check sequence is a bit
662          * different from OpenBSD, so we jump over as few code as
663          * possible, to catch _all_ sanity checks. This needs
664          * evaluation, to see if the carp ether_dhost values break any
665          * of these checks!
666          */
667 	if (ifp->if_carp && carp_forus(ifp->if_carp, eh.ether_dhost))
668 		goto pre_stats;
669 #endif
670 
671 	/*
672 	 * Discard packet if upper layers shouldn't see it because
673 	 * it was unicast to a different Ethernet address.  If the
674 	 * driver is working properly, then this situation can only
675 	 * happen when the interface is in promiscuous mode.
676 	 */
677 	if (((ifp->if_flags & (IFF_PROMISC | IFF_PPROMISC)) == IFF_PROMISC) &&
678 	    (eh.ether_dhost[0] & 1) == 0 &&
679 	    bcmp(eh.ether_dhost, IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN)) {
680 		m_freem(m);
681 		return;
682 	}
683 
684 #ifdef CARP
685 pre_stats:
686 #endif
687 
688 	/* Discard packet if interface is not up */
689 	if (!(ifp->if_flags & IFF_UP)) {
690 		m_freem(m);
691 		return;
692 	}
693 	if (eh.ether_dhost[0] & 1) {
694 		if (bcmp(ifp->if_broadcastaddr, eh.ether_dhost,
695 			 ifp->if_addrlen) == 0)
696 			m->m_flags |= M_BCAST;
697 		else
698 			m->m_flags |= M_MCAST;
699 		ifp->if_imcasts++;
700 	}
701 
702 post_stats:
703 	if (IPFW_LOADED && ether_ipfw != 0) {
704 		if (!ether_ipfw_chk(&m, NULL, &rule, &eh, FALSE)) {
705 			m_freem(m);
706 			return;
707 		}
708 	}
709 
710 	ether_type = ntohs(eh.ether_type);
711 
712 	switch (ether_type) {
713 #ifdef INET
714 	case ETHERTYPE_IP:
715 		if (ipflow_fastforward(m, ifp->if_serializer))
716 			return;
717 		isr = NETISR_IP;
718 		break;
719 
720 	case ETHERTYPE_ARP:
721 		if (ifp->if_flags & IFF_NOARP) {
722 			/* Discard packet if ARP is disabled on interface */
723 			m_freem(m);
724 			return;
725 		}
726 		isr = NETISR_ARP;
727 		break;
728 #endif
729 
730 #ifdef INET6
731 	case ETHERTYPE_IPV6:
732 		isr = NETISR_IPV6;
733 		break;
734 #endif
735 
736 #ifdef IPX
737 	case ETHERTYPE_IPX:
738 		if (ef_inputp && ef_inputp(ifp, &eh, m) == 0)
739 			return;
740 		isr = NETISR_IPX;
741 		break;
742 #endif
743 
744 #ifdef NS
745 	case 0x8137: /* Novell Ethernet_II Ethernet TYPE II */
746 		isr = NETISR_NS;
747 		break;
748 
749 #endif
750 
751 #ifdef NETATALK
752 	case ETHERTYPE_AT:
753 		isr = NETISR_ATALK1;
754 		break;
755 	case ETHERTYPE_AARP:
756 		isr = NETISR_AARP;
757 		break;
758 #endif
759 
760 	case ETHERTYPE_VLAN:
761 		if (vlan_input_p != NULL)
762 			(*vlan_input_p)(&eh, m);
763 		else {
764 			m->m_pkthdr.rcvif->if_noproto++;
765 			m_freem(m);
766 		}
767 		return;
768 
769 	default:
770 #ifdef IPX
771 		if (ef_inputp && ef_inputp(ifp, &eh, m) == 0)
772 			return;
773 #endif
774 #ifdef NS
775 		checksum = mtod(m, ushort *);
776 		/* Novell 802.3 */
777 		if ((ether_type <= ETHERMTU) &&
778 		    ((*checksum == 0xffff) || (*checksum == 0xE0E0))) {
779 			if (*checksum == 0xE0E0) {
780 				m->m_pkthdr.len -= 3;
781 				m->m_len -= 3;
782 				m->m_data += 3;
783 			}
784 			isr = NETISR_NS;
785 			break;
786 		}
787 #endif
788 #ifdef NETATALK
789 		if (ether_type > ETHERMTU)
790 			goto dropanyway;
791 		l = mtod(m, struct llc *);
792 		if (l->llc_dsap == LLC_SNAP_LSAP &&
793 		    l->llc_ssap == LLC_SNAP_LSAP &&
794 		    l->llc_control == LLC_UI) {
795 			if (bcmp(&(l->llc_snap_org_code)[0], at_org_code,
796 				 sizeof at_org_code) == 0 &&
797 			    ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
798 				m_adj(m, sizeof(struct llc));
799 				isr = NETISR_ATALK2;
800 				break;
801 			}
802 			if (bcmp(&(l->llc_snap_org_code)[0], aarp_org_code,
803 				 sizeof aarp_org_code) == 0 &&
804 			    ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) {
805 				m_adj(m, sizeof(struct llc));
806 				isr = NETISR_AARP;
807 				break;
808 			}
809 		}
810 dropanyway:
811 #endif
812 		if (ng_ether_input_orphan_p != NULL)
813 			(*ng_ether_input_orphan_p)(ifp, m, &eh);
814 		else
815 			m_freem(m);
816 		return;
817 	}
818 	netisr_dispatch(isr, m);
819 }
820 
821 /*
822  * Perform common duties while attaching to interface list
823  */
824 
825 void
826 ether_ifattach(struct ifnet *ifp, uint8_t *lla, lwkt_serialize_t serializer)
827 {
828 	ether_ifattach_bpf(ifp, lla, DLT_EN10MB, sizeof(struct ether_header),
829 			   serializer);
830 }
831 
832 void
833 ether_ifattach_bpf(struct ifnet *ifp, uint8_t *lla, u_int dlt, u_int hdrlen,
834 		   lwkt_serialize_t serializer)
835 {
836 	struct sockaddr_dl *sdl;
837 
838 	ifp->if_type = IFT_ETHER;
839 	ifp->if_addrlen = ETHER_ADDR_LEN;
840 	ifp->if_hdrlen = ETHER_HDR_LEN;
841 	if_attach(ifp, serializer);
842 	ifp->if_mtu = ETHERMTU;
843 	if (ifp->if_baudrate == 0)
844 		ifp->if_baudrate = 10000000;
845 	ifp->if_output = ether_output;
846 	ifp->if_input = ether_input;
847 	ifp->if_resolvemulti = ether_resolvemulti;
848 	ifp->if_broadcastaddr = etherbroadcastaddr;
849 	sdl = IF_LLSOCKADDR(ifp);
850 	sdl->sdl_type = IFT_ETHER;
851 	sdl->sdl_alen = ifp->if_addrlen;
852 	bcopy(lla, LLADDR(sdl), ifp->if_addrlen);
853 	/*
854 	 * XXX Keep the current drivers happy.
855 	 * XXX Remove once all drivers have been cleaned up
856 	 */
857 	if (lla != IFP2AC(ifp)->ac_enaddr)
858 		bcopy(lla, IFP2AC(ifp)->ac_enaddr, ifp->if_addrlen);
859 	bpfattach(ifp, dlt, hdrlen);
860 	if (ng_ether_attach_p != NULL)
861 		(*ng_ether_attach_p)(ifp);
862 
863 	if_printf(ifp, "MAC address: %6D\n", lla, ":");
864 }
865 
866 /*
867  * Perform common duties while detaching an Ethernet interface
868  */
869 void
870 ether_ifdetach(struct ifnet *ifp)
871 {
872 	if_down(ifp);
873 
874 	if (ng_ether_detach_p != NULL)
875 		(*ng_ether_detach_p)(ifp);
876 	bpfdetach(ifp);
877 	if_detach(ifp);
878 }
879 
880 int
881 ether_ioctl(struct ifnet *ifp, int command, caddr_t data)
882 {
883 	struct ifaddr *ifa = (struct ifaddr *) data;
884 	struct ifreq *ifr = (struct ifreq *) data;
885 	int error = 0;
886 
887 #define IF_INIT(ifp) \
888 do { \
889 	if (((ifp)->if_flags & IFF_UP) == 0) { \
890 		(ifp)->if_flags |= IFF_UP; \
891 		(ifp)->if_init((ifp)->if_softc); \
892 	} \
893 } while (0)
894 
895 	ASSERT_SERIALIZED(ifp->if_serializer);
896 
897 	switch (command) {
898 	case SIOCSIFADDR:
899 		switch (ifa->ifa_addr->sa_family) {
900 #ifdef INET
901 		case AF_INET:
902 			IF_INIT(ifp);	/* before arpwhohas */
903 			arp_ifinit(ifp, ifa);
904 			break;
905 #endif
906 #ifdef IPX
907 		/*
908 		 * XXX - This code is probably wrong
909 		 */
910 		case AF_IPX:
911 			{
912 			struct ipx_addr *ina = &IA_SIPX(ifa)->sipx_addr;
913 			struct arpcom *ac = IFP2AC(ifp);
914 
915 			if (ipx_nullhost(*ina))
916 				ina->x_host = *(union ipx_host *) ac->ac_enaddr;
917 			else
918 				bcopy(ina->x_host.c_host, ac->ac_enaddr,
919 				      sizeof ac->ac_enaddr);
920 
921 			IF_INIT(ifp);	/* Set new address. */
922 			break;
923 			}
924 #endif
925 #ifdef NS
926 		/*
927 		 * XXX - This code is probably wrong
928 		 */
929 		case AF_NS:
930 		{
931 			struct ns_addr *ina = &(IA_SNS(ifa)->sns_addr);
932 			struct arpcom *ac = IFP2AC(ifp);
933 
934 			if (ns_nullhost(*ina))
935 				ina->x_host = *(union ns_host *)(ac->ac_enaddr);
936 			else
937 				bcopy(ina->x_host.c_host, ac->ac_enaddr,
938 				      sizeof ac->ac_enaddr);
939 
940 			/*
941 			 * Set new address
942 			 */
943 			IF_INIT(ifp);
944 			break;
945 		}
946 #endif
947 		default:
948 			IF_INIT(ifp);
949 			break;
950 		}
951 		break;
952 
953 	case SIOCGIFADDR:
954 		bcopy(IFP2AC(ifp)->ac_enaddr,
955 		      ((struct sockaddr *)ifr->ifr_data)->sa_data,
956 		      ETHER_ADDR_LEN);
957 		break;
958 
959 	case SIOCSIFMTU:
960 		/*
961 		 * Set the interface MTU.
962 		 */
963 		if (ifr->ifr_mtu > ETHERMTU) {
964 			error = EINVAL;
965 		} else {
966 			ifp->if_mtu = ifr->ifr_mtu;
967 		}
968 		break;
969 	default:
970 		error = EINVAL;
971 		break;
972 	}
973 	return (error);
974 
975 #undef IF_INIT
976 }
977 
978 int
979 ether_resolvemulti(
980 	struct ifnet *ifp,
981 	struct sockaddr **llsa,
982 	struct sockaddr *sa)
983 {
984 	struct sockaddr_dl *sdl;
985 	struct sockaddr_in *sin;
986 #ifdef INET6
987 	struct sockaddr_in6 *sin6;
988 #endif
989 	u_char *e_addr;
990 
991 	switch(sa->sa_family) {
992 	case AF_LINK:
993 		/*
994 		 * No mapping needed. Just check that it's a valid MC address.
995 		 */
996 		sdl = (struct sockaddr_dl *)sa;
997 		e_addr = LLADDR(sdl);
998 		if ((e_addr[0] & 1) != 1)
999 			return EADDRNOTAVAIL;
1000 		*llsa = 0;
1001 		return 0;
1002 
1003 #ifdef INET
1004 	case AF_INET:
1005 		sin = (struct sockaddr_in *)sa;
1006 		if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
1007 			return EADDRNOTAVAIL;
1008 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1009 		       M_WAITOK | M_ZERO);
1010 		sdl->sdl_len = sizeof *sdl;
1011 		sdl->sdl_family = AF_LINK;
1012 		sdl->sdl_index = ifp->if_index;
1013 		sdl->sdl_type = IFT_ETHER;
1014 		sdl->sdl_alen = ETHER_ADDR_LEN;
1015 		e_addr = LLADDR(sdl);
1016 		ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
1017 		*llsa = (struct sockaddr *)sdl;
1018 		return 0;
1019 #endif
1020 #ifdef INET6
1021 	case AF_INET6:
1022 		sin6 = (struct sockaddr_in6 *)sa;
1023 		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1024 			/*
1025 			 * An IP6 address of 0 means listen to all
1026 			 * of the Ethernet multicast address used for IP6.
1027 			 * (This is used for multicast routers.)
1028 			 */
1029 			ifp->if_flags |= IFF_ALLMULTI;
1030 			*llsa = 0;
1031 			return 0;
1032 		}
1033 		if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
1034 			return EADDRNOTAVAIL;
1035 		MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
1036 		       M_WAITOK | M_ZERO);
1037 		sdl->sdl_len = sizeof *sdl;
1038 		sdl->sdl_family = AF_LINK;
1039 		sdl->sdl_index = ifp->if_index;
1040 		sdl->sdl_type = IFT_ETHER;
1041 		sdl->sdl_alen = ETHER_ADDR_LEN;
1042 		e_addr = LLADDR(sdl);
1043 		ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
1044 		*llsa = (struct sockaddr *)sdl;
1045 		return 0;
1046 #endif
1047 
1048 	default:
1049 		/*
1050 		 * Well, the text isn't quite right, but it's the name
1051 		 * that counts...
1052 		 */
1053 		return EAFNOSUPPORT;
1054 	}
1055 }
1056 
1057 #if 0
1058 /*
1059  * This is for reference.  We have a table-driven version
1060  * of the little-endian crc32 generator, which is faster
1061  * than the double-loop.
1062  */
1063 uint32_t
1064 ether_crc32_le(const uint8_t *buf, size_t len)
1065 {
1066 	uint32_t c, crc, carry;
1067 	size_t i, j;
1068 
1069 	crc = 0xffffffffU;	/* initial value */
1070 
1071 	for (i = 0; i < len; i++) {
1072 		c = buf[i];
1073 		for (j = 0; j < 8; j++) {
1074 			carry = ((crc & 0x01) ? 1 : 0) ^ (c & 0x01);
1075 			crc >>= 1;
1076 			c >>= 1;
1077 			if (carry)
1078 				crc = (crc ^ ETHER_CRC_POLY_LE);
1079 		}
1080 	}
1081 
1082 	return (crc);
1083 }
1084 #else
1085 uint32_t
1086 ether_crc32_le(const uint8_t *buf, size_t len)
1087 {
1088 	static const uint32_t crctab[] = {
1089 		0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1090 		0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1091 		0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1092 		0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1093 	};
1094 	uint32_t crc;
1095 	size_t i;
1096 
1097 	crc = 0xffffffffU;	/* initial value */
1098 
1099 	for (i = 0; i < len; i++) {
1100 		crc ^= buf[i];
1101 		crc = (crc >> 4) ^ crctab[crc & 0xf];
1102 		crc = (crc >> 4) ^ crctab[crc & 0xf];
1103 	}
1104 
1105 	return (crc);
1106 }
1107 #endif
1108 
1109 uint32_t
1110 ether_crc32_be(const uint8_t *buf, size_t len)
1111 {
1112 	uint32_t c, crc, carry;
1113 	size_t i, j;
1114 
1115 	crc = 0xffffffffU;	/* initial value */
1116 
1117 	for (i = 0; i < len; i++) {
1118 		c = buf[i];
1119 		for (j = 0; j < 8; j++) {
1120 			carry = ((crc & 0x80000000U) ? 1 : 0) ^ (c & 0x01);
1121 			crc <<= 1;
1122 			c >>= 1;
1123 			if (carry)
1124 				crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
1125 		}
1126 	}
1127 
1128 	return (crc);
1129 }
1130 
1131 /*
1132  * find the size of ethernet header, and call classifier
1133  */
1134 void
1135 altq_etherclassify(struct ifaltq *ifq, struct mbuf *m,
1136 		   struct altq_pktattr *pktattr)
1137 {
1138 	struct ether_header *eh;
1139 	uint16_t ether_type;
1140 	int hlen, af, hdrsize;
1141 	caddr_t hdr;
1142 
1143 	hlen = sizeof(struct ether_header);
1144 	eh = mtod(m, struct ether_header *);
1145 
1146 	ether_type = ntohs(eh->ether_type);
1147 	if (ether_type < ETHERMTU) {
1148 		/* ick! LLC/SNAP */
1149 		struct llc *llc = (struct llc *)(eh + 1);
1150 		hlen += 8;
1151 
1152 		if (m->m_len < hlen ||
1153 		    llc->llc_dsap != LLC_SNAP_LSAP ||
1154 		    llc->llc_ssap != LLC_SNAP_LSAP ||
1155 		    llc->llc_control != LLC_UI)
1156 			goto bad;  /* not snap! */
1157 
1158 		ether_type = ntohs(llc->llc_un.type_snap.ether_type);
1159 	}
1160 
1161 	if (ether_type == ETHERTYPE_IP) {
1162 		af = AF_INET;
1163 		hdrsize = 20;  /* sizeof(struct ip) */
1164 #ifdef INET6
1165 	} else if (ether_type == ETHERTYPE_IPV6) {
1166 		af = AF_INET6;
1167 		hdrsize = 40;  /* sizeof(struct ip6_hdr) */
1168 #endif
1169 	} else
1170 		goto bad;
1171 
1172 	while (m->m_len <= hlen) {
1173 		hlen -= m->m_len;
1174 		m = m->m_next;
1175 	}
1176 	hdr = m->m_data + hlen;
1177 	if (m->m_len < hlen + hdrsize) {
1178 		/*
1179 		 * ip header is not in a single mbuf.  this should not
1180 		 * happen in the current code.
1181 		 * (todo: use m_pulldown in the future)
1182 		 */
1183 		goto bad;
1184 	}
1185 	m->m_data += hlen;
1186 	m->m_len -= hlen;
1187 	ifq_classify(ifq, m, af, pktattr);
1188 	m->m_data -= hlen;
1189 	m->m_len += hlen;
1190 
1191 	return;
1192 
1193 bad:
1194 	pktattr->pattr_class = NULL;
1195 	pktattr->pattr_hdr = NULL;
1196 	pktattr->pattr_af = AF_UNSPEC;
1197 }
1198