1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
32 * $FreeBSD$
33 */
34
35#include "opt_inet.h"
36#include "opt_inet6.h"
37#include "opt_netgraph.h"
38#include "opt_mbuf_profiling.h"
39#include "opt_rss.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/devctl.h>
44#include <sys/eventhandler.h>
45#include <sys/jail.h>
46#include <sys/kernel.h>
47#include <sys/lock.h>
48#include <sys/malloc.h>
49#include <sys/module.h>
50#include <sys/mbuf.h>
51#include <sys/proc.h>
52#include <sys/priv.h>
53#include <sys/random.h>
54#include <sys/socket.h>
55#include <sys/sockio.h>
56#include <sys/sysctl.h>
57#include <sys/uuid.h>
58
59#include <net/ieee_oui.h>
60#include <net/if.h>
61#include <net/if_var.h>
62#include <net/if_arp.h>
63#include <net/netisr.h>
64#include <net/route.h>
65#include <net/if_llc.h>
66#include <net/if_dl.h>
67#include <net/if_types.h>
68#include <net/bpf.h>
69#include <net/ethernet.h>
70#include <net/if_bridgevar.h>
71#include <net/if_vlan_var.h>
72#include <net/if_llatbl.h>
73#include <net/pfil.h>
74#include <net/rss_config.h>
75#include <net/vnet.h>
76
77#include <netpfil/pf/pf_mtag.h>
78
79#if defined(INET) || defined(INET6)
80#include <netinet/in.h>
81#include <netinet/in_var.h>
82#include <netinet/if_ether.h>
83#include <netinet/ip_carp.h>
84#include <netinet/ip_var.h>
85#endif
86#ifdef INET6
87#include <netinet6/nd6.h>
88#endif
89#include <security/mac/mac_framework.h>
90
91#include <crypto/sha1.h>
92
93#ifdef CTASSERT
94CTASSERT(sizeof (struct ether_header) == ETHER_ADDR_LEN * 2 + 2);
95CTASSERT(sizeof (struct ether_addr) == ETHER_ADDR_LEN);
96#endif
97
98VNET_DEFINE(pfil_head_t, link_pfil_head);	/* Packet filter hooks */
99
100/* netgraph node hooks for ng_ether(4) */
101void	(*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
102void	(*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
103int	(*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
104void	(*ng_ether_attach_p)(struct ifnet *ifp);
105void	(*ng_ether_detach_p)(struct ifnet *ifp);
106
107void	(*vlan_input_p)(struct ifnet *, struct mbuf *);
108
109/* if_bridge(4) support */
110void	(*bridge_dn_p)(struct mbuf *, struct ifnet *);
111
112/* if_lagg(4) support */
113struct mbuf *(*lagg_input_ethernet_p)(struct ifnet *, struct mbuf *);
114
115static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
116			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
117
118static	int ether_resolvemulti(struct ifnet *, struct sockaddr **,
119		struct sockaddr *);
120static	int ether_requestencap(struct ifnet *, struct if_encap_req *);
121
122#define senderr(e) do { error = (e); goto bad;} while (0)
123
124static void
125update_mbuf_csumflags(struct mbuf *src, struct mbuf *dst)
126{
127	int csum_flags = 0;
128
129	if (src->m_pkthdr.csum_flags & CSUM_IP)
130		csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
131	if (src->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
132		csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
133	if (src->m_pkthdr.csum_flags & CSUM_SCTP)
134		csum_flags |= CSUM_SCTP_VALID;
135	dst->m_pkthdr.csum_flags |= csum_flags;
136	if (csum_flags & CSUM_DATA_VALID)
137		dst->m_pkthdr.csum_data = 0xffff;
138}
139
140/*
141 * Handle link-layer encapsulation requests.
142 */
143static int
144ether_requestencap(struct ifnet *ifp, struct if_encap_req *req)
145{
146	struct ether_header *eh;
147	struct arphdr *ah;
148	uint16_t etype;
149	const u_char *lladdr;
150
151	if (req->rtype != IFENCAP_LL)
152		return (EOPNOTSUPP);
153
154	if (req->bufsize < ETHER_HDR_LEN)
155		return (ENOMEM);
156
157	eh = (struct ether_header *)req->buf;
158	lladdr = req->lladdr;
159	req->lladdr_off = 0;
160
161	switch (req->family) {
162	case AF_INET:
163		etype = htons(ETHERTYPE_IP);
164		break;
165	case AF_INET6:
166		etype = htons(ETHERTYPE_IPV6);
167		break;
168	case AF_ARP:
169		ah = (struct arphdr *)req->hdata;
170		ah->ar_hrd = htons(ARPHRD_ETHER);
171
172		switch(ntohs(ah->ar_op)) {
173		case ARPOP_REVREQUEST:
174		case ARPOP_REVREPLY:
175			etype = htons(ETHERTYPE_REVARP);
176			break;
177		case ARPOP_REQUEST:
178		case ARPOP_REPLY:
179		default:
180			etype = htons(ETHERTYPE_ARP);
181			break;
182		}
183
184		if (req->flags & IFENCAP_FLAG_BROADCAST)
185			lladdr = ifp->if_broadcastaddr;
186		break;
187	default:
188		return (EAFNOSUPPORT);
189	}
190
191	memcpy(&eh->ether_type, &etype, sizeof(eh->ether_type));
192	memcpy(eh->ether_dhost, lladdr, ETHER_ADDR_LEN);
193	memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
194	req->bufsize = sizeof(struct ether_header);
195
196	return (0);
197}
198
199static int
200ether_resolve_addr(struct ifnet *ifp, struct mbuf *m,
201	const struct sockaddr *dst, struct route *ro, u_char *phdr,
202	uint32_t *pflags, struct llentry **plle)
203{
204	struct ether_header *eh;
205	uint32_t lleflags = 0;
206	int error = 0;
207#if defined(INET) || defined(INET6)
208	uint16_t etype;
209#endif
210
211	if (plle)
212		*plle = NULL;
213	eh = (struct ether_header *)phdr;
214
215	switch (dst->sa_family) {
216#ifdef INET
217	case AF_INET:
218		if ((m->m_flags & (M_BCAST | M_MCAST)) == 0)
219			error = arpresolve(ifp, 0, m, dst, phdr, &lleflags,
220			    plle);
221		else {
222			if (m->m_flags & M_BCAST)
223				memcpy(eh->ether_dhost, ifp->if_broadcastaddr,
224				    ETHER_ADDR_LEN);
225			else {
226				const struct in_addr *a;
227				a = &(((const struct sockaddr_in *)dst)->sin_addr);
228				ETHER_MAP_IP_MULTICAST(a, eh->ether_dhost);
229			}
230			etype = htons(ETHERTYPE_IP);
231			memcpy(&eh->ether_type, &etype, sizeof(etype));
232			memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
233		}
234		break;
235#endif
236#ifdef INET6
237	case AF_INET6:
238		if ((m->m_flags & M_MCAST) == 0)
239			error = nd6_resolve(ifp, 0, m, dst, phdr, &lleflags,
240			    plle);
241		else {
242			const struct in6_addr *a6;
243			a6 = &(((const struct sockaddr_in6 *)dst)->sin6_addr);
244			ETHER_MAP_IPV6_MULTICAST(a6, eh->ether_dhost);
245			etype = htons(ETHERTYPE_IPV6);
246			memcpy(&eh->ether_type, &etype, sizeof(etype));
247			memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
248		}
249		break;
250#endif
251	default:
252		if_printf(ifp, "can't handle af%d\n", dst->sa_family);
253		if (m != NULL)
254			m_freem(m);
255		return (EAFNOSUPPORT);
256	}
257
258	if (error == EHOSTDOWN) {
259		if (ro != NULL && (ro->ro_flags & RT_HAS_GW) != 0)
260			error = EHOSTUNREACH;
261	}
262
263	if (error != 0)
264		return (error);
265
266	*pflags = RT_MAY_LOOP;
267	if (lleflags & LLE_IFADDR)
268		*pflags |= RT_L2_ME;
269
270	return (0);
271}
272
273/*
274 * Ethernet output routine.
275 * Encapsulate a packet of type family for the local net.
276 * Use trailer local net encapsulation if enough data in first
277 * packet leaves a multiple of 512 bytes of data in remainder.
278 */
279int
280ether_output(struct ifnet *ifp, struct mbuf *m,
281	const struct sockaddr *dst, struct route *ro)
282{
283	int error = 0;
284	char linkhdr[ETHER_HDR_LEN], *phdr;
285	struct ether_header *eh;
286	struct pf_mtag *t;
287	bool loop_copy;
288	int hlen;	/* link layer header length */
289	uint32_t pflags;
290	struct llentry *lle = NULL;
291	int addref = 0;
292
293	phdr = NULL;
294	pflags = 0;
295	if (ro != NULL) {
296		/* XXX BPF uses ro_prepend */
297		if (ro->ro_prepend != NULL) {
298			phdr = ro->ro_prepend;
299			hlen = ro->ro_plen;
300		} else if (!(m->m_flags & (M_BCAST | M_MCAST))) {
301			if ((ro->ro_flags & RT_LLE_CACHE) != 0) {
302				lle = ro->ro_lle;
303				if (lle != NULL &&
304				    (lle->la_flags & LLE_VALID) == 0) {
305					LLE_FREE(lle);
306					lle = NULL;	/* redundant */
307					ro->ro_lle = NULL;
308				}
309				if (lle == NULL) {
310					/* if we lookup, keep cache */
311					addref = 1;
312				} else
313					/*
314					 * Notify LLE code that
315					 * the entry was used
316					 * by datapath.
317					 */
318					llentry_mark_used(lle);
319			}
320			if (lle != NULL) {
321				phdr = lle->r_linkdata;
322				hlen = lle->r_hdrlen;
323				pflags = lle->r_flags;
324			}
325		}
326	}
327
328#ifdef MAC
329	error = mac_ifnet_check_transmit(ifp, m);
330	if (error)
331		senderr(error);
332#endif
333
334	M_PROFILE(m);
335	if (ifp->if_flags & IFF_MONITOR)
336		senderr(ENETDOWN);
337	if (!((ifp->if_flags & IFF_UP) &&
338	    (ifp->if_drv_flags & IFF_DRV_RUNNING)))
339		senderr(ENETDOWN);
340
341	if (phdr == NULL) {
342		/* No prepend data supplied. Try to calculate ourselves. */
343		phdr = linkhdr;
344		hlen = ETHER_HDR_LEN;
345		error = ether_resolve_addr(ifp, m, dst, ro, phdr, &pflags,
346		    addref ? &lle : NULL);
347		if (addref && lle != NULL)
348			ro->ro_lle = lle;
349		if (error != 0)
350			return (error == EWOULDBLOCK ? 0 : error);
351	}
352
353	if ((pflags & RT_L2_ME) != 0) {
354		update_mbuf_csumflags(m, m);
355		return (if_simloop(ifp, m, dst->sa_family, 0));
356	}
357	loop_copy = (pflags & RT_MAY_LOOP) != 0;
358
359	/*
360	 * Add local net header.  If no space in first mbuf,
361	 * allocate another.
362	 *
363	 * Note that we do prepend regardless of RT_HAS_HEADER flag.
364	 * This is done because BPF code shifts m_data pointer
365	 * to the end of ethernet header prior to calling if_output().
366	 */
367	M_PREPEND(m, hlen, M_NOWAIT);
368	if (m == NULL)
369		senderr(ENOBUFS);
370	if ((pflags & RT_HAS_HEADER) == 0) {
371		eh = mtod(m, struct ether_header *);
372		memcpy(eh, phdr, hlen);
373	}
374
375	/*
376	 * If a simplex interface, and the packet is being sent to our
377	 * Ethernet address or a broadcast address, loopback a copy.
378	 * XXX To make a simplex device behave exactly like a duplex
379	 * device, we should copy in the case of sending to our own
380	 * ethernet address (thus letting the original actually appear
381	 * on the wire). However, we don't do that here for security
382	 * reasons and compatibility with the original behavior.
383	 */
384	if ((m->m_flags & M_BCAST) && loop_copy && (ifp->if_flags & IFF_SIMPLEX) &&
385	    ((t = pf_find_mtag(m)) == NULL || !t->routed)) {
386		struct mbuf *n;
387
388		/*
389		 * Because if_simloop() modifies the packet, we need a
390		 * writable copy through m_dup() instead of a readonly
391		 * one as m_copy[m] would give us. The alternative would
392		 * be to modify if_simloop() to handle the readonly mbuf,
393		 * but performancewise it is mostly equivalent (trading
394		 * extra data copying vs. extra locking).
395		 *
396		 * XXX This is a local workaround.  A number of less
397		 * often used kernel parts suffer from the same bug.
398		 * See PR kern/105943 for a proposed general solution.
399		 */
400		if ((n = m_dup(m, M_NOWAIT)) != NULL) {
401			update_mbuf_csumflags(m, n);
402			(void)if_simloop(ifp, n, dst->sa_family, hlen);
403		} else
404			if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
405	}
406
407       /*
408	* Bridges require special output handling.
409	*/
410	if (ifp->if_bridge) {
411		BRIDGE_OUTPUT(ifp, m, error);
412		return (error);
413	}
414
415#if defined(INET) || defined(INET6)
416	if (ifp->if_carp &&
417	    (error = (*carp_output_p)(ifp, m, dst)))
418		goto bad;
419#endif
420
421	/* Handle ng_ether(4) processing, if any */
422	if (ifp->if_l2com != NULL) {
423		KASSERT(ng_ether_output_p != NULL,
424		    ("ng_ether_output_p is NULL"));
425		if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
426bad:			if (m != NULL)
427				m_freem(m);
428			return (error);
429		}
430		if (m == NULL)
431			return (0);
432	}
433
434	/* Continue with link-layer output */
435	return ether_output_frame(ifp, m);
436}
437
438static bool
439ether_set_pcp(struct mbuf **mp, struct ifnet *ifp, uint8_t pcp)
440{
441	struct ether_8021q_tag qtag;
442	struct ether_header *eh;
443
444	eh = mtod(*mp, struct ether_header *);
445	if (ntohs(eh->ether_type) == ETHERTYPE_VLAN ||
446	    ntohs(eh->ether_type) == ETHERTYPE_QINQ)
447		return (true);
448
449	qtag.vid = 0;
450	qtag.pcp = pcp;
451	qtag.proto = ETHERTYPE_VLAN;
452	if (ether_8021q_frame(mp, ifp, ifp, &qtag))
453		return (true);
454	if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
455	return (false);
456}
457
458/*
459 * Ethernet link layer output routine to send a raw frame to the device.
460 *
461 * This assumes that the 14 byte Ethernet header is present and contiguous
462 * in the first mbuf (if BRIDGE'ing).
463 */
464int
465ether_output_frame(struct ifnet *ifp, struct mbuf *m)
466{
467	uint8_t pcp;
468
469	pcp = ifp->if_pcp;
470	if (pcp != IFNET_PCP_NONE && ifp->if_type != IFT_L2VLAN &&
471	    !ether_set_pcp(&m, ifp, pcp))
472		return (0);
473
474	if (PFIL_HOOKED_OUT(V_link_pfil_head))
475		switch (pfil_run_hooks(V_link_pfil_head, &m, ifp, PFIL_OUT,
476		    NULL)) {
477		case PFIL_DROPPED:
478			return (EACCES);
479		case PFIL_CONSUMED:
480			return (0);
481		}
482
483#ifdef EXPERIMENTAL
484#if defined(INET6) && defined(INET)
485	/* draft-ietf-6man-ipv6only-flag */
486	/* Catch ETHERTYPE_IP, and ETHERTYPE_[REV]ARP if we are v6-only. */
487	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IPV6_ONLY_MASK) != 0) {
488		struct ether_header *eh;
489
490		eh = mtod(m, struct ether_header *);
491		switch (ntohs(eh->ether_type)) {
492		case ETHERTYPE_IP:
493		case ETHERTYPE_ARP:
494		case ETHERTYPE_REVARP:
495			m_freem(m);
496			return (EAFNOSUPPORT);
497			/* NOTREACHED */
498			break;
499		};
500	}
501#endif
502#endif
503
504	/*
505	 * Queue message on interface, update output statistics if
506	 * successful, and start output if interface not yet active.
507	 */
508	return ((ifp->if_transmit)(ifp, m));
509}
510
511/*
512 * Process a received Ethernet packet; the packet is in the
513 * mbuf chain m with the ethernet header at the front.
514 */
515static void
516ether_input_internal(struct ifnet *ifp, struct mbuf *m)
517{
518	struct ether_header *eh;
519	u_short etype;
520
521	if ((ifp->if_flags & IFF_UP) == 0) {
522		m_freem(m);
523		return;
524	}
525#ifdef DIAGNOSTIC
526	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
527		if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n");
528		m_freem(m);
529		return;
530	}
531#endif
532	if (m->m_len < ETHER_HDR_LEN) {
533		/* XXX maybe should pullup? */
534		if_printf(ifp, "discard frame w/o leading ethernet "
535				"header (len %u pkt len %u)\n",
536				m->m_len, m->m_pkthdr.len);
537		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
538		m_freem(m);
539		return;
540	}
541	eh = mtod(m, struct ether_header *);
542	etype = ntohs(eh->ether_type);
543	random_harvest_queue_ether(m, sizeof(*m));
544
545#ifdef EXPERIMENTAL
546#if defined(INET6) && defined(INET)
547	/* draft-ietf-6man-ipv6only-flag */
548	/* Catch ETHERTYPE_IP, and ETHERTYPE_[REV]ARP if we are v6-only. */
549	if ((ND_IFINFO(ifp)->flags & ND6_IFF_IPV6_ONLY_MASK) != 0) {
550		switch (etype) {
551		case ETHERTYPE_IP:
552		case ETHERTYPE_ARP:
553		case ETHERTYPE_REVARP:
554			m_freem(m);
555			return;
556			/* NOTREACHED */
557			break;
558		};
559	}
560#endif
561#endif
562
563	CURVNET_SET_QUIET(ifp->if_vnet);
564
565	if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
566		if (ETHER_IS_BROADCAST(eh->ether_dhost))
567			m->m_flags |= M_BCAST;
568		else
569			m->m_flags |= M_MCAST;
570		if_inc_counter(ifp, IFCOUNTER_IMCASTS, 1);
571	}
572
573#ifdef MAC
574	/*
575	 * Tag the mbuf with an appropriate MAC label before any other
576	 * consumers can get to it.
577	 */
578	mac_ifnet_create_mbuf(ifp, m);
579#endif
580
581	/*
582	 * Give bpf a chance at the packet.
583	 */
584	ETHER_BPF_MTAP(ifp, m);
585
586	/*
587	 * If the CRC is still on the packet, trim it off. We do this once
588	 * and once only in case we are re-entered. Nothing else on the
589	 * Ethernet receive path expects to see the FCS.
590	 */
591	if (m->m_flags & M_HASFCS) {
592		m_adj(m, -ETHER_CRC_LEN);
593		m->m_flags &= ~M_HASFCS;
594	}
595
596	if (!(ifp->if_capenable & IFCAP_HWSTATS))
597		if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
598
599	/* Allow monitor mode to claim this frame, after stats are updated. */
600	if (ifp->if_flags & IFF_MONITOR) {
601		m_freem(m);
602		CURVNET_RESTORE();
603		return;
604	}
605
606	/* Handle input from a lagg(4) port */
607	if (ifp->if_type == IFT_IEEE8023ADLAG) {
608		KASSERT(lagg_input_ethernet_p != NULL,
609		    ("%s: if_lagg not loaded!", __func__));
610		m = (*lagg_input_ethernet_p)(ifp, m);
611		if (m != NULL)
612			ifp = m->m_pkthdr.rcvif;
613		else {
614			CURVNET_RESTORE();
615			return;
616		}
617	}
618
619	/*
620	 * If the hardware did not process an 802.1Q tag, do this now,
621	 * to allow 802.1P priority frames to be passed to the main input
622	 * path correctly.
623	 */
624	if ((m->m_flags & M_VLANTAG) == 0 &&
625	    ((etype == ETHERTYPE_VLAN) || (etype == ETHERTYPE_QINQ))) {
626		struct ether_vlan_header *evl;
627
628		if (m->m_len < sizeof(*evl) &&
629		    (m = m_pullup(m, sizeof(*evl))) == NULL) {
630#ifdef DIAGNOSTIC
631			if_printf(ifp, "cannot pullup VLAN header\n");
632#endif
633			if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
634			CURVNET_RESTORE();
635			return;
636		}
637
638		evl = mtod(m, struct ether_vlan_header *);
639		m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag);
640		m->m_flags |= M_VLANTAG;
641
642		bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN,
643		    ETHER_HDR_LEN - ETHER_TYPE_LEN);
644		m_adj(m, ETHER_VLAN_ENCAP_LEN);
645		eh = mtod(m, struct ether_header *);
646	}
647
648	M_SETFIB(m, ifp->if_fib);
649
650	/* Allow ng_ether(4) to claim this frame. */
651	if (ifp->if_l2com != NULL) {
652		KASSERT(ng_ether_input_p != NULL,
653		    ("%s: ng_ether_input_p is NULL", __func__));
654		m->m_flags &= ~M_PROMISC;
655		(*ng_ether_input_p)(ifp, &m);
656		if (m == NULL) {
657			CURVNET_RESTORE();
658			return;
659		}
660		eh = mtod(m, struct ether_header *);
661	}
662
663	/*
664	 * Allow if_bridge(4) to claim this frame.
665	 * The BRIDGE_INPUT() macro will update ifp if the bridge changed it
666	 * and the frame should be delivered locally.
667	 */
668	if (ifp->if_bridge != NULL) {
669		m->m_flags &= ~M_PROMISC;
670		BRIDGE_INPUT(ifp, m);
671		if (m == NULL) {
672			CURVNET_RESTORE();
673			return;
674		}
675		eh = mtod(m, struct ether_header *);
676	}
677
678#if defined(INET) || defined(INET6)
679	/*
680	 * Clear M_PROMISC on frame so that carp(4) will see it when the
681	 * mbuf flows up to Layer 3.
682	 * FreeBSD's implementation of carp(4) uses the inprotosw
683	 * to dispatch IPPROTO_CARP. carp(4) also allocates its own
684	 * Ethernet addresses of the form 00:00:5e:00:01:xx, which
685	 * is outside the scope of the M_PROMISC test below.
686	 * TODO: Maintain a hash table of ethernet addresses other than
687	 * ether_dhost which may be active on this ifp.
688	 */
689	if (ifp->if_carp && (*carp_forus_p)(ifp, eh->ether_dhost)) {
690		m->m_flags &= ~M_PROMISC;
691	} else
692#endif
693	{
694		/*
695		 * If the frame received was not for our MAC address, set the
696		 * M_PROMISC flag on the mbuf chain. The frame may need to
697		 * be seen by the rest of the Ethernet input path in case of
698		 * re-entry (e.g. bridge, vlan, netgraph) but should not be
699		 * seen by upper protocol layers.
700		 */
701		if (!ETHER_IS_MULTICAST(eh->ether_dhost) &&
702		    bcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0)
703			m->m_flags |= M_PROMISC;
704	}
705
706	ether_demux(ifp, m);
707	CURVNET_RESTORE();
708}
709
710/*
711 * Ethernet input dispatch; by default, direct dispatch here regardless of
712 * global configuration.  However, if RSS is enabled, hook up RSS affinity
713 * so that when deferred or hybrid dispatch is enabled, we can redistribute
714 * load based on RSS.
715 *
716 * XXXRW: Would be nice if the ifnet passed up a flag indicating whether or
717 * not it had already done work distribution via multi-queue.  Then we could
718 * direct dispatch in the event load balancing was already complete and
719 * handle the case of interfaces with different capabilities better.
720 *
721 * XXXRW: Sort of want an M_DISTRIBUTED flag to avoid multiple distributions
722 * at multiple layers?
723 *
724 * XXXRW: For now, enable all this only if RSS is compiled in, although it
725 * works fine without RSS.  Need to characterise the performance overhead
726 * of the detour through the netisr code in the event the result is always
727 * direct dispatch.
728 */
729static void
730ether_nh_input(struct mbuf *m)
731{
732
733	M_ASSERTPKTHDR(m);
734	KASSERT(m->m_pkthdr.rcvif != NULL,
735	    ("%s: NULL interface pointer", __func__));
736	ether_input_internal(m->m_pkthdr.rcvif, m);
737}
738
739static struct netisr_handler	ether_nh = {
740	.nh_name = "ether",
741	.nh_handler = ether_nh_input,
742	.nh_proto = NETISR_ETHER,
743#ifdef RSS
744	.nh_policy = NETISR_POLICY_CPU,
745	.nh_dispatch = NETISR_DISPATCH_DIRECT,
746	.nh_m2cpuid = rss_m2cpuid,
747#else
748	.nh_policy = NETISR_POLICY_SOURCE,
749	.nh_dispatch = NETISR_DISPATCH_DIRECT,
750#endif
751};
752
753static void
754ether_init(__unused void *arg)
755{
756
757	netisr_register(&ether_nh);
758}
759SYSINIT(ether, SI_SUB_INIT_IF, SI_ORDER_ANY, ether_init, NULL);
760
761static void
762vnet_ether_init(__unused void *arg)
763{
764	struct pfil_head_args args;
765
766	args.pa_version = PFIL_VERSION;
767	args.pa_flags = PFIL_IN | PFIL_OUT;
768	args.pa_type = PFIL_TYPE_ETHERNET;
769	args.pa_headname = PFIL_ETHER_NAME;
770	V_link_pfil_head = pfil_head_register(&args);
771
772#ifdef VIMAGE
773	netisr_register_vnet(&ether_nh);
774#endif
775}
776VNET_SYSINIT(vnet_ether_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
777    vnet_ether_init, NULL);
778
779#ifdef VIMAGE
780static void
781vnet_ether_pfil_destroy(__unused void *arg)
782{
783
784	pfil_head_unregister(V_link_pfil_head);
785}
786VNET_SYSUNINIT(vnet_ether_pfil_uninit, SI_SUB_PROTO_PFIL, SI_ORDER_ANY,
787    vnet_ether_pfil_destroy, NULL);
788
789static void
790vnet_ether_destroy(__unused void *arg)
791{
792
793	netisr_unregister_vnet(&ether_nh);
794}
795VNET_SYSUNINIT(vnet_ether_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
796    vnet_ether_destroy, NULL);
797#endif
798
799static void
800ether_input(struct ifnet *ifp, struct mbuf *m)
801{
802	struct epoch_tracker et;
803	struct mbuf *mn;
804	bool needs_epoch;
805
806	needs_epoch = !(ifp->if_flags & IFF_KNOWSEPOCH);
807
808	/*
809	 * The drivers are allowed to pass in a chain of packets linked with
810	 * m_nextpkt. We split them up into separate packets here and pass
811	 * them up. This allows the drivers to amortize the receive lock.
812	 */
813	CURVNET_SET_QUIET(ifp->if_vnet);
814	if (__predict_false(needs_epoch))
815		NET_EPOCH_ENTER(et);
816	while (m) {
817		mn = m->m_nextpkt;
818		m->m_nextpkt = NULL;
819
820		/*
821		 * We will rely on rcvif being set properly in the deferred
822		 * context, so assert it is correct here.
823		 */
824		MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
825		KASSERT(m->m_pkthdr.rcvif == ifp, ("%s: ifnet mismatch m %p "
826		    "rcvif %p ifp %p", __func__, m, m->m_pkthdr.rcvif, ifp));
827		netisr_dispatch(NETISR_ETHER, m);
828		m = mn;
829	}
830	if (__predict_false(needs_epoch))
831		NET_EPOCH_EXIT(et);
832	CURVNET_RESTORE();
833}
834
835/*
836 * Upper layer processing for a received Ethernet packet.
837 */
838void
839ether_demux(struct ifnet *ifp, struct mbuf *m)
840{
841	struct ether_header *eh;
842	int i, isr;
843	u_short ether_type;
844
845	NET_EPOCH_ASSERT();
846	KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__));
847
848	/* Do not grab PROMISC frames in case we are re-entered. */
849	if (PFIL_HOOKED_IN(V_link_pfil_head) && !(m->m_flags & M_PROMISC)) {
850		i = pfil_run_hooks(V_link_pfil_head, &m, ifp, PFIL_IN, NULL);
851		if (i != 0 || m == NULL)
852			return;
853	}
854
855	eh = mtod(m, struct ether_header *);
856	ether_type = ntohs(eh->ether_type);
857
858	/*
859	 * If this frame has a VLAN tag other than 0, call vlan_input()
860	 * if its module is loaded. Otherwise, drop.
861	 */
862	if ((m->m_flags & M_VLANTAG) &&
863	    EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) {
864		if (ifp->if_vlantrunk == NULL) {
865			if_inc_counter(ifp, IFCOUNTER_NOPROTO, 1);
866			m_freem(m);
867			return;
868		}
869		KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!",
870		    __func__));
871		/* Clear before possibly re-entering ether_input(). */
872		m->m_flags &= ~M_PROMISC;
873		(*vlan_input_p)(ifp, m);
874		return;
875	}
876
877	/*
878	 * Pass promiscuously received frames to the upper layer if the user
879	 * requested this by setting IFF_PPROMISC. Otherwise, drop them.
880	 */
881	if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) {
882		m_freem(m);
883		return;
884	}
885
886	/*
887	 * Reset layer specific mbuf flags to avoid confusing upper layers.
888	 * Strip off Ethernet header.
889	 */
890	m->m_flags &= ~M_VLANTAG;
891	m_clrprotoflags(m);
892	m_adj(m, ETHER_HDR_LEN);
893
894	/*
895	 * Dispatch frame to upper layer.
896	 */
897	switch (ether_type) {
898#ifdef INET
899	case ETHERTYPE_IP:
900		isr = NETISR_IP;
901		break;
902
903	case ETHERTYPE_ARP:
904		if (ifp->if_flags & IFF_NOARP) {
905			/* Discard packet if ARP is disabled on interface */
906			m_freem(m);
907			return;
908		}
909		isr = NETISR_ARP;
910		break;
911#endif
912#ifdef INET6
913	case ETHERTYPE_IPV6:
914		isr = NETISR_IPV6;
915		break;
916#endif
917	default:
918		goto discard;
919	}
920	netisr_dispatch(isr, m);
921	return;
922
923discard:
924	/*
925	 * Packet is to be discarded.  If netgraph is present,
926	 * hand the packet to it for last chance processing;
927	 * otherwise dispose of it.
928	 */
929	if (ifp->if_l2com != NULL) {
930		KASSERT(ng_ether_input_orphan_p != NULL,
931		    ("ng_ether_input_orphan_p is NULL"));
932		/*
933		 * Put back the ethernet header so netgraph has a
934		 * consistent view of inbound packets.
935		 */
936		M_PREPEND(m, ETHER_HDR_LEN, M_NOWAIT);
937		(*ng_ether_input_orphan_p)(ifp, m);
938		return;
939	}
940	m_freem(m);
941}
942
943/*
944 * Convert Ethernet address to printable (loggable) representation.
945 * This routine is for compatibility; it's better to just use
946 *
947 *	printf("%6D", <pointer to address>, ":");
948 *
949 * since there's no static buffer involved.
950 */
951char *
952ether_sprintf(const u_char *ap)
953{
954	static char etherbuf[18];
955	snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":");
956	return (etherbuf);
957}
958
959/*
960 * Perform common duties while attaching to interface list
961 */
962void
963ether_ifattach(struct ifnet *ifp, const u_int8_t *lla)
964{
965	int i;
966	struct ifaddr *ifa;
967	struct sockaddr_dl *sdl;
968
969	ifp->if_addrlen = ETHER_ADDR_LEN;
970	ifp->if_hdrlen = ETHER_HDR_LEN;
971	ifp->if_mtu = ETHERMTU;
972	if_attach(ifp);
973	ifp->if_output = ether_output;
974	ifp->if_input = ether_input;
975	ifp->if_resolvemulti = ether_resolvemulti;
976	ifp->if_requestencap = ether_requestencap;
977#ifdef VIMAGE
978	ifp->if_reassign = ether_reassign;
979#endif
980	if (ifp->if_baudrate == 0)
981		ifp->if_baudrate = IF_Mbps(10);		/* just a default */
982	ifp->if_broadcastaddr = etherbroadcastaddr;
983
984	ifa = ifp->if_addr;
985	KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
986	sdl = (struct sockaddr_dl *)ifa->ifa_addr;
987	sdl->sdl_type = IFT_ETHER;
988	sdl->sdl_alen = ifp->if_addrlen;
989	bcopy(lla, LLADDR(sdl), ifp->if_addrlen);
990
991	if (ifp->if_hw_addr != NULL)
992		bcopy(lla, ifp->if_hw_addr, ifp->if_addrlen);
993
994	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
995	if (ng_ether_attach_p != NULL)
996		(*ng_ether_attach_p)(ifp);
997
998	/* Announce Ethernet MAC address if non-zero. */
999	for (i = 0; i < ifp->if_addrlen; i++)
1000		if (lla[i] != 0)
1001			break;
1002	if (i != ifp->if_addrlen)
1003		if_printf(ifp, "Ethernet address: %6D\n", lla, ":");
1004
1005	uuid_ether_add(LLADDR(sdl));
1006
1007	/* Add necessary bits are setup; announce it now. */
1008	EVENTHANDLER_INVOKE(ether_ifattach_event, ifp);
1009	if (IS_DEFAULT_VNET(curvnet))
1010		devctl_notify("ETHERNET", ifp->if_xname, "IFATTACH", NULL);
1011}
1012
1013/*
1014 * Perform common duties while detaching an Ethernet interface
1015 */
1016void
1017ether_ifdetach(struct ifnet *ifp)
1018{
1019	struct sockaddr_dl *sdl;
1020
1021	sdl = (struct sockaddr_dl *)(ifp->if_addr->ifa_addr);
1022	uuid_ether_del(LLADDR(sdl));
1023
1024	if (ifp->if_l2com != NULL) {
1025		KASSERT(ng_ether_detach_p != NULL,
1026		    ("ng_ether_detach_p is NULL"));
1027		(*ng_ether_detach_p)(ifp);
1028	}
1029
1030	bpfdetach(ifp);
1031	if_detach(ifp);
1032}
1033
1034#ifdef VIMAGE
1035void
1036ether_reassign(struct ifnet *ifp, struct vnet *new_vnet, char *unused __unused)
1037{
1038
1039	if (ifp->if_l2com != NULL) {
1040		KASSERT(ng_ether_detach_p != NULL,
1041		    ("ng_ether_detach_p is NULL"));
1042		(*ng_ether_detach_p)(ifp);
1043	}
1044
1045	if (ng_ether_attach_p != NULL) {
1046		CURVNET_SET_QUIET(new_vnet);
1047		(*ng_ether_attach_p)(ifp);
1048		CURVNET_RESTORE();
1049	}
1050}
1051#endif
1052
1053SYSCTL_DECL(_net_link);
1054SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1055    "Ethernet");
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 */
1063uint32_t
1064ether_crc32_le(const uint8_t *buf, size_t len)
1065{
1066	size_t i;
1067	uint32_t crc;
1068	int bit;
1069	uint8_t data;
1070
1071	crc = 0xffffffff;	/* initial value */
1072
1073	for (i = 0; i < len; i++) {
1074		for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
1075			carry = (crc ^ data) & 1;
1076			crc >>= 1;
1077			if (carry)
1078				crc = (crc ^ ETHER_CRC_POLY_LE);
1079		}
1080	}
1081
1082	return (crc);
1083}
1084#else
1085uint32_t
1086ether_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	size_t i;
1095	uint32_t crc;
1096
1097	crc = 0xffffffff;	/* 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
1109uint32_t
1110ether_crc32_be(const uint8_t *buf, size_t len)
1111{
1112	size_t i;
1113	uint32_t crc, carry;
1114	int bit;
1115	uint8_t data;
1116
1117	crc = 0xffffffff;	/* initial value */
1118
1119	for (i = 0; i < len; i++) {
1120		for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
1121			carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01);
1122			crc <<= 1;
1123			if (carry)
1124				crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
1125		}
1126	}
1127
1128	return (crc);
1129}
1130
1131int
1132ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
1133{
1134	struct ifaddr *ifa = (struct ifaddr *) data;
1135	struct ifreq *ifr = (struct ifreq *) data;
1136	int error = 0;
1137
1138	switch (command) {
1139	case SIOCSIFADDR:
1140		ifp->if_flags |= IFF_UP;
1141
1142		switch (ifa->ifa_addr->sa_family) {
1143#ifdef INET
1144		case AF_INET:
1145			ifp->if_init(ifp->if_softc);	/* before arpwhohas */
1146			arp_ifinit(ifp, ifa);
1147			break;
1148#endif
1149		default:
1150			ifp->if_init(ifp->if_softc);
1151			break;
1152		}
1153		break;
1154
1155	case SIOCGIFADDR:
1156		bcopy(IF_LLADDR(ifp), &ifr->ifr_addr.sa_data[0],
1157		    ETHER_ADDR_LEN);
1158		break;
1159
1160	case SIOCSIFMTU:
1161		/*
1162		 * Set the interface MTU.
1163		 */
1164		if (ifr->ifr_mtu > ETHERMTU) {
1165			error = EINVAL;
1166		} else {
1167			ifp->if_mtu = ifr->ifr_mtu;
1168		}
1169		break;
1170
1171	case SIOCSLANPCP:
1172		error = priv_check(curthread, PRIV_NET_SETLANPCP);
1173		if (error != 0)
1174			break;
1175		if (ifr->ifr_lan_pcp > 7 &&
1176		    ifr->ifr_lan_pcp != IFNET_PCP_NONE) {
1177			error = EINVAL;
1178		} else {
1179			ifp->if_pcp = ifr->ifr_lan_pcp;
1180			/* broadcast event about PCP change */
1181			EVENTHANDLER_INVOKE(ifnet_event, ifp, IFNET_EVENT_PCP);
1182		}
1183		break;
1184
1185	case SIOCGLANPCP:
1186		ifr->ifr_lan_pcp = ifp->if_pcp;
1187		break;
1188
1189	default:
1190		error = EINVAL;			/* XXX netbsd has ENOTTY??? */
1191		break;
1192	}
1193	return (error);
1194}
1195
1196static int
1197ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
1198	struct sockaddr *sa)
1199{
1200	struct sockaddr_dl *sdl;
1201#ifdef INET
1202	struct sockaddr_in *sin;
1203#endif
1204#ifdef INET6
1205	struct sockaddr_in6 *sin6;
1206#endif
1207	u_char *e_addr;
1208
1209	switch(sa->sa_family) {
1210	case AF_LINK:
1211		/*
1212		 * No mapping needed. Just check that it's a valid MC address.
1213		 */
1214		sdl = (struct sockaddr_dl *)sa;
1215		e_addr = LLADDR(sdl);
1216		if (!ETHER_IS_MULTICAST(e_addr))
1217			return EADDRNOTAVAIL;
1218		*llsa = NULL;
1219		return 0;
1220
1221#ifdef INET
1222	case AF_INET:
1223		sin = (struct sockaddr_in *)sa;
1224		if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
1225			return EADDRNOTAVAIL;
1226		sdl = link_init_sdl(ifp, *llsa, IFT_ETHER);
1227		sdl->sdl_alen = ETHER_ADDR_LEN;
1228		e_addr = LLADDR(sdl);
1229		ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
1230		*llsa = (struct sockaddr *)sdl;
1231		return 0;
1232#endif
1233#ifdef INET6
1234	case AF_INET6:
1235		sin6 = (struct sockaddr_in6 *)sa;
1236		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1237			/*
1238			 * An IP6 address of 0 means listen to all
1239			 * of the Ethernet multicast address used for IP6.
1240			 * (This is used for multicast routers.)
1241			 */
1242			ifp->if_flags |= IFF_ALLMULTI;
1243			*llsa = NULL;
1244			return 0;
1245		}
1246		if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
1247			return EADDRNOTAVAIL;
1248		sdl = link_init_sdl(ifp, *llsa, IFT_ETHER);
1249		sdl->sdl_alen = ETHER_ADDR_LEN;
1250		e_addr = LLADDR(sdl);
1251		ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
1252		*llsa = (struct sockaddr *)sdl;
1253		return 0;
1254#endif
1255
1256	default:
1257		/*
1258		 * Well, the text isn't quite right, but it's the name
1259		 * that counts...
1260		 */
1261		return EAFNOSUPPORT;
1262	}
1263}
1264
1265static moduledata_t ether_mod = {
1266	.name = "ether",
1267};
1268
1269void
1270ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen)
1271{
1272	struct ether_vlan_header vlan;
1273	struct mbuf mv, mb;
1274
1275	KASSERT((m->m_flags & M_VLANTAG) != 0,
1276	    ("%s: vlan information not present", __func__));
1277	KASSERT(m->m_len >= sizeof(struct ether_header),
1278	    ("%s: mbuf not large enough for header", __func__));
1279	bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header));
1280	vlan.evl_proto = vlan.evl_encap_proto;
1281	vlan.evl_encap_proto = htons(ETHERTYPE_VLAN);
1282	vlan.evl_tag = htons(m->m_pkthdr.ether_vtag);
1283	m->m_len -= sizeof(struct ether_header);
1284	m->m_data += sizeof(struct ether_header);
1285	/*
1286	 * If a data link has been supplied by the caller, then we will need to
1287	 * re-create a stack allocated mbuf chain with the following structure:
1288	 *
1289	 * (1) mbuf #1 will contain the supplied data link
1290	 * (2) mbuf #2 will contain the vlan header
1291	 * (3) mbuf #3 will contain the original mbuf's packet data
1292	 *
1293	 * Otherwise, submit the packet and vlan header via bpf_mtap2().
1294	 */
1295	if (data != NULL) {
1296		mv.m_next = m;
1297		mv.m_data = (caddr_t)&vlan;
1298		mv.m_len = sizeof(vlan);
1299		mb.m_next = &mv;
1300		mb.m_data = data;
1301		mb.m_len = dlen;
1302		bpf_mtap(bp, &mb);
1303	} else
1304		bpf_mtap2(bp, &vlan, sizeof(vlan), m);
1305	m->m_len += sizeof(struct ether_header);
1306	m->m_data -= sizeof(struct ether_header);
1307}
1308
1309struct mbuf *
1310ether_vlanencap_proto(struct mbuf *m, uint16_t tag, uint16_t proto)
1311{
1312	struct ether_vlan_header *evl;
1313
1314	M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
1315	if (m == NULL)
1316		return (NULL);
1317	/* M_PREPEND takes care of m_len, m_pkthdr.len for us */
1318
1319	if (m->m_len < sizeof(*evl)) {
1320		m = m_pullup(m, sizeof(*evl));
1321		if (m == NULL)
1322			return (NULL);
1323	}
1324
1325	/*
1326	 * Transform the Ethernet header into an Ethernet header
1327	 * with 802.1Q encapsulation.
1328	 */
1329	evl = mtod(m, struct ether_vlan_header *);
1330	bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN,
1331	    (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
1332	evl->evl_encap_proto = htons(proto);
1333	evl->evl_tag = htons(tag);
1334	return (m);
1335}
1336
1337static SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1338    "IEEE 802.1Q VLAN");
1339static SYSCTL_NODE(_net_link_vlan, PF_LINK, link,
1340    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1341    "for consistency");
1342
1343VNET_DEFINE_STATIC(int, soft_pad);
1344#define	V_soft_pad	VNET(soft_pad)
1345SYSCTL_INT(_net_link_vlan, OID_AUTO, soft_pad, CTLFLAG_RW | CTLFLAG_VNET,
1346    &VNET_NAME(soft_pad), 0,
1347    "pad short frames before tagging");
1348
1349/*
1350 * For now, make preserving PCP via an mbuf tag optional, as it increases
1351 * per-packet memory allocations and frees.  In the future, it would be
1352 * preferable to reuse ether_vtag for this, or similar.
1353 */
1354int vlan_mtag_pcp = 0;
1355SYSCTL_INT(_net_link_vlan, OID_AUTO, mtag_pcp, CTLFLAG_RW,
1356    &vlan_mtag_pcp, 0,
1357    "Retain VLAN PCP information as packets are passed up the stack");
1358
1359bool
1360ether_8021q_frame(struct mbuf **mp, struct ifnet *ife, struct ifnet *p,
1361    struct ether_8021q_tag *qtag)
1362{
1363	struct m_tag *mtag;
1364	int n;
1365	uint16_t tag;
1366	static const char pad[8];	/* just zeros */
1367
1368	/*
1369	 * Pad the frame to the minimum size allowed if told to.
1370	 * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
1371	 * paragraph C.4.4.3.b.  It can help to work around buggy
1372	 * bridges that violate paragraph C.4.4.3.a from the same
1373	 * document, i.e., fail to pad short frames after untagging.
1374	 * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
1375	 * untagging it will produce a 62-byte frame, which is a runt
1376	 * and requires padding.  There are VLAN-enabled network
1377	 * devices that just discard such runts instead or mishandle
1378	 * them somehow.
1379	 */
1380	if (V_soft_pad && p->if_type == IFT_ETHER) {
1381		for (n = ETHERMIN + ETHER_HDR_LEN - (*mp)->m_pkthdr.len;
1382		     n > 0; n -= sizeof(pad)) {
1383			if (!m_append(*mp, min(n, sizeof(pad)), pad))
1384				break;
1385		}
1386		if (n > 0) {
1387			m_freem(*mp);
1388			*mp = NULL;
1389			if_printf(ife, "cannot pad short frame");
1390			return (false);
1391		}
1392	}
1393
1394	/*
1395	 * If PCP is set in mbuf, use it
1396	 */
1397	if ((*mp)->m_flags & M_VLANTAG) {
1398		qtag->pcp = EVL_PRIOFTAG((*mp)->m_pkthdr.ether_vtag);
1399	}
1400
1401	/*
1402	 * If underlying interface can do VLAN tag insertion itself,
1403	 * just pass the packet along. However, we need some way to
1404	 * tell the interface where the packet came from so that it
1405	 * knows how to find the VLAN tag to use, so we attach a
1406	 * packet tag that holds it.
1407	 */
1408	if (vlan_mtag_pcp && (mtag = m_tag_locate(*mp, MTAG_8021Q,
1409	    MTAG_8021Q_PCP_OUT, NULL)) != NULL)
1410		tag = EVL_MAKETAG(qtag->vid, *(uint8_t *)(mtag + 1), 0);
1411	else
1412		tag = EVL_MAKETAG(qtag->vid, qtag->pcp, 0);
1413	if ((p->if_capenable & IFCAP_VLAN_HWTAGGING) &&
1414	    (qtag->proto == ETHERTYPE_VLAN)) {
1415		(*mp)->m_pkthdr.ether_vtag = tag;
1416		(*mp)->m_flags |= M_VLANTAG;
1417	} else {
1418		*mp = ether_vlanencap_proto(*mp, tag, qtag->proto);
1419		if (*mp == NULL) {
1420			if_printf(ife, "unable to prepend 802.1Q header");
1421			return (false);
1422		}
1423	}
1424	return (true);
1425}
1426
1427/*
1428 * Allocate an address from the FreeBSD Foundation OUI.  This uses a
1429 * cryptographic hash function on the containing jail's name, UUID and the
1430 * interface name to attempt to provide a unique but stable address.
1431 * Pseudo-interfaces which require a MAC address should use this function to
1432 * allocate non-locally-administered addresses.
1433 */
1434void
1435ether_gen_addr(struct ifnet *ifp, struct ether_addr *hwaddr)
1436{
1437	SHA1_CTX ctx;
1438	char *buf;
1439	char uuid[HOSTUUIDLEN + 1];
1440	uint64_t addr;
1441	int i, sz;
1442	char digest[SHA1_RESULTLEN];
1443	char jailname[MAXHOSTNAMELEN];
1444
1445	getcredhostuuid(curthread->td_ucred, uuid, sizeof(uuid));
1446	/* If each (vnet) jail would also have a unique hostuuid this would not
1447	 * be necessary. */
1448	getjailname(curthread->td_ucred, jailname, sizeof(jailname));
1449	sz = asprintf(&buf, M_TEMP, "%s-%s-%s", uuid, if_name(ifp),
1450	    jailname);
1451	if (sz < 0) {
1452		/* Fall back to a random mac address. */
1453		arc4rand(hwaddr, sizeof(*hwaddr), 0);
1454		hwaddr->octet[0] = 0x02;
1455		return;
1456	}
1457
1458	SHA1Init(&ctx);
1459	SHA1Update(&ctx, buf, sz);
1460	SHA1Final(digest, &ctx);
1461	free(buf, M_TEMP);
1462
1463	addr = ((digest[0] << 16) | (digest[1] << 8) | digest[2]) &
1464	    OUI_FREEBSD_GENERATED_MASK;
1465	addr = OUI_FREEBSD(addr);
1466	for (i = 0; i < ETHER_ADDR_LEN; ++i) {
1467		hwaddr->octet[i] = addr >> ((ETHER_ADDR_LEN - i - 1) * 8) &
1468		    0xFF;
1469	}
1470}
1471
1472DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
1473MODULE_VERSION(ether, 1);
1474