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
32 #include "opt_inet.h"
33 #include "opt_inet6.h"
34 #include "opt_netgraph.h"
35 #include "opt_mbuf_profiling.h"
36 #include "opt_rss.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/devctl.h>
41 #include <sys/eventhandler.h>
42 #include <sys/jail.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/module.h>
48 #include <sys/msan.h>
49 #include <sys/proc.h>
50 #include <sys/priv.h>
51 #include <sys/random.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/sysctl.h>
55 #include <sys/uuid.h>
56 #ifdef KDB
57 #include <sys/kdb.h>
58 #endif
59
60 #include <net/ieee_oui.h>
61 #include <net/if.h>
62 #include <net/if_var.h>
63 #include <net/if_private.h>
64 #include <net/if_arp.h>
65 #include <net/netisr.h>
66 #include <net/route.h>
67 #include <net/if_llc.h>
68 #include <net/if_dl.h>
69 #include <net/if_types.h>
70 #include <net/bpf.h>
71 #include <net/ethernet.h>
72 #include <net/if_bridgevar.h>
73 #include <net/if_vlan_var.h>
74 #include <net/if_llatbl.h>
75 #include <net/pfil.h>
76 #include <net/rss_config.h>
77 #include <net/vnet.h>
78
79 #include <netpfil/pf/pf_mtag.h>
80
81 #if defined(INET) || defined(INET6)
82 #include <netinet/in.h>
83 #include <netinet/in_var.h>
84 #include <netinet/if_ether.h>
85 #include <netinet/ip_carp.h>
86 #include <netinet/ip_var.h>
87 #endif
88 #ifdef INET6
89 #include <netinet6/nd6.h>
90 #endif
91 #include <security/mac/mac_framework.h>
92
93 #include <crypto/sha1.h>
94
95 VNET_DEFINE(pfil_head_t, link_pfil_head); /* Packet filter hooks */
96
97 /* netgraph node hooks for ng_ether(4) */
98 void (*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
99 void (*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
100 int (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
101
102 /* if_bridge(4) support */
103 void (*bridge_dn_p)(struct mbuf *, struct ifnet *);
104 bool (*bridge_same_p)(const void *, const void *);
105 void *(*bridge_get_softc_p)(struct ifnet *);
106 bool (*bridge_member_ifaddrs_p)(void);
107
108 /* if_lagg(4) support */
109 struct mbuf *(*lagg_input_ethernet_p)(struct ifnet *, struct mbuf *);
110
111 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
112 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
113
114 static int ether_resolvemulti(struct ifnet *, struct sockaddr **,
115 struct sockaddr *);
116 static int ether_requestencap(struct ifnet *, struct if_encap_req *);
117
118 static inline bool ether_do_pcp(struct ifnet *, struct mbuf *);
119
120 #define senderr(e) do { error = (e); goto bad;} while (0)
121
122 static void
update_mbuf_csumflags(struct mbuf * src,struct mbuf * dst)123 update_mbuf_csumflags(struct mbuf *src, struct mbuf *dst)
124 {
125 int csum_flags = 0;
126
127 if (src->m_pkthdr.csum_flags & CSUM_IP)
128 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
129 if (src->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
130 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
131 if (src->m_pkthdr.csum_flags & CSUM_SCTP)
132 csum_flags |= CSUM_SCTP_VALID;
133 dst->m_pkthdr.csum_flags |= csum_flags;
134 if (csum_flags & CSUM_DATA_VALID)
135 dst->m_pkthdr.csum_data = 0xffff;
136 }
137
138 /*
139 * Handle link-layer encapsulation requests.
140 */
141 static int
ether_requestencap(struct ifnet * ifp,struct if_encap_req * req)142 ether_requestencap(struct ifnet *ifp, struct if_encap_req *req)
143 {
144 struct ether_header *eh;
145 struct arphdr *ah;
146 uint16_t etype;
147 const u_char *lladdr;
148
149 if (req->rtype != IFENCAP_LL)
150 return (EOPNOTSUPP);
151
152 if (req->bufsize < ETHER_HDR_LEN)
153 return (ENOMEM);
154
155 eh = (struct ether_header *)req->buf;
156 lladdr = req->lladdr;
157 req->lladdr_off = 0;
158
159 switch (req->family) {
160 case AF_INET:
161 etype = htons(ETHERTYPE_IP);
162 break;
163 case AF_INET6:
164 etype = htons(ETHERTYPE_IPV6);
165 break;
166 case AF_ARP:
167 ah = (struct arphdr *)req->hdata;
168 ah->ar_hrd = htons(ARPHRD_ETHER);
169
170 switch(ntohs(ah->ar_op)) {
171 case ARPOP_REVREQUEST:
172 case ARPOP_REVREPLY:
173 etype = htons(ETHERTYPE_REVARP);
174 break;
175 case ARPOP_REQUEST:
176 case ARPOP_REPLY:
177 default:
178 etype = htons(ETHERTYPE_ARP);
179 break;
180 }
181
182 if (req->flags & IFENCAP_FLAG_BROADCAST)
183 lladdr = ifp->if_broadcastaddr;
184 break;
185 default:
186 return (EAFNOSUPPORT);
187 }
188
189 memcpy(&eh->ether_type, &etype, sizeof(eh->ether_type));
190 memcpy(eh->ether_dhost, lladdr, ETHER_ADDR_LEN);
191 memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
192 req->bufsize = sizeof(struct ether_header);
193
194 return (0);
195 }
196
197 static int
ether_resolve_addr(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro,u_char * phdr,uint32_t * pflags,struct llentry ** plle)198 ether_resolve_addr(struct ifnet *ifp, struct mbuf *m,
199 const struct sockaddr *dst, struct route *ro, u_char *phdr,
200 uint32_t *pflags, struct llentry **plle)
201 {
202 uint32_t lleflags = 0;
203 int error = 0;
204 #if defined(INET) || defined(INET6)
205 struct ether_header *eh = (struct ether_header *)phdr;
206 uint16_t etype;
207 #endif
208
209 if (plle)
210 *plle = NULL;
211
212 switch (dst->sa_family) {
213 #ifdef INET
214 case AF_INET:
215 if ((m->m_flags & (M_BCAST | M_MCAST)) == 0)
216 error = arpresolve(ifp, 0, m, dst, phdr, &lleflags,
217 plle);
218 else {
219 if (m->m_flags & M_BCAST)
220 memcpy(eh->ether_dhost, ifp->if_broadcastaddr,
221 ETHER_ADDR_LEN);
222 else {
223 const struct in_addr *a;
224 a = &(((const struct sockaddr_in *)dst)->sin_addr);
225 ETHER_MAP_IP_MULTICAST(a, eh->ether_dhost);
226 }
227 etype = htons(ETHERTYPE_IP);
228 memcpy(&eh->ether_type, &etype, sizeof(etype));
229 memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
230 }
231 break;
232 #endif
233 #ifdef INET6
234 case AF_INET6:
235 if ((m->m_flags & M_MCAST) == 0) {
236 int af = RO_GET_FAMILY(ro, dst);
237 error = nd6_resolve(ifp, LLE_SF(af, 0), m, dst, phdr,
238 &lleflags, plle);
239 } else {
240 const struct in6_addr *a6;
241 a6 = &(((const struct sockaddr_in6 *)dst)->sin6_addr);
242 ETHER_MAP_IPV6_MULTICAST(a6, eh->ether_dhost);
243 etype = htons(ETHERTYPE_IPV6);
244 memcpy(&eh->ether_type, &etype, sizeof(etype));
245 memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
246 }
247 break;
248 #endif
249 default:
250 if_printf(ifp, "can't handle af%d\n", dst->sa_family);
251 if (m != NULL)
252 m_freem(m);
253 return (EAFNOSUPPORT);
254 }
255
256 if (error == EHOSTDOWN) {
257 if (ro != NULL && (ro->ro_flags & RT_HAS_GW) != 0)
258 error = EHOSTUNREACH;
259 }
260
261 if (error != 0)
262 return (error);
263
264 *pflags = RT_MAY_LOOP;
265 if (lleflags & LLE_IFADDR)
266 *pflags |= RT_L2_ME;
267
268 return (0);
269 }
270
271 /*
272 * Ethernet output routine.
273 * Encapsulate a packet of type family for the local net.
274 * Use trailer local net encapsulation if enough data in first
275 * packet leaves a multiple of 512 bytes of data in remainder.
276 */
277 int
ether_output(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)278 ether_output(struct ifnet *ifp, struct mbuf *m,
279 const struct sockaddr *dst, struct route *ro)
280 {
281 int error = 0;
282 char linkhdr[ETHER_HDR_LEN], *phdr;
283 struct ether_header *eh;
284 struct pf_mtag *t;
285 bool loop_copy;
286 int hlen; /* link layer header length */
287 uint32_t pflags;
288 struct llentry *lle = NULL;
289 int addref = 0;
290
291 phdr = NULL;
292 pflags = 0;
293 if (ro != NULL) {
294 /* XXX BPF uses ro_prepend */
295 if (ro->ro_prepend != NULL) {
296 phdr = ro->ro_prepend;
297 hlen = ro->ro_plen;
298 } else if (!(m->m_flags & (M_BCAST | M_MCAST))) {
299 if ((ro->ro_flags & RT_LLE_CACHE) != 0) {
300 lle = ro->ro_lle;
301 if (lle != NULL &&
302 (lle->la_flags & LLE_VALID) == 0) {
303 LLE_FREE(lle);
304 lle = NULL; /* redundant */
305 ro->ro_lle = NULL;
306 }
307 if (lle == NULL) {
308 /* if we lookup, keep cache */
309 addref = 1;
310 } else
311 /*
312 * Notify LLE code that
313 * the entry was used
314 * by datapath.
315 */
316 llentry_provide_feedback(lle);
317 }
318 if (lle != NULL) {
319 phdr = lle->r_linkdata;
320 hlen = lle->r_hdrlen;
321 pflags = lle->r_flags;
322 }
323 }
324 }
325
326 #ifdef MAC
327 error = mac_ifnet_check_transmit(ifp, m);
328 if (error)
329 senderr(error);
330 #endif
331
332 M_PROFILE(m);
333 if (ifp->if_flags & IFF_MONITOR)
334 senderr(ENETDOWN);
335 if (!((ifp->if_flags & IFF_UP) &&
336 (ifp->if_drv_flags & IFF_DRV_RUNNING)))
337 senderr(ENETDOWN);
338
339 if (phdr == NULL) {
340 /* No prepend data supplied. Try to calculate ourselves. */
341 phdr = linkhdr;
342 hlen = ETHER_HDR_LEN;
343 error = ether_resolve_addr(ifp, m, dst, ro, phdr, &pflags,
344 addref ? &lle : NULL);
345 if (addref && lle != NULL)
346 ro->ro_lle = lle;
347 if (error != 0)
348 return (error == EWOULDBLOCK ? 0 : error);
349 }
350
351 if ((pflags & RT_L2_ME) != 0) {
352 update_mbuf_csumflags(m, m);
353 return (if_simloop(ifp, m, RO_GET_FAMILY(ro, dst), 0));
354 }
355 loop_copy = (pflags & RT_MAY_LOOP) != 0;
356
357 /*
358 * Add local net header. If no space in first mbuf,
359 * allocate another.
360 *
361 * Note that we do prepend regardless of RT_HAS_HEADER flag.
362 * This is done because BPF code shifts m_data pointer
363 * to the end of ethernet header prior to calling if_output().
364 */
365 M_PREPEND(m, hlen, M_NOWAIT);
366 if (m == NULL)
367 senderr(ENOBUFS);
368 if ((pflags & RT_HAS_HEADER) == 0) {
369 eh = mtod(m, struct ether_header *);
370 memcpy(eh, phdr, hlen);
371 }
372
373 /*
374 * If a simplex interface, and the packet is being sent to our
375 * Ethernet address or a broadcast address, loopback a copy.
376 * XXX To make a simplex device behave exactly like a duplex
377 * device, we should copy in the case of sending to our own
378 * ethernet address (thus letting the original actually appear
379 * on the wire). However, we don't do that here for security
380 * reasons and compatibility with the original behavior.
381 */
382 if ((m->m_flags & M_BCAST) && loop_copy && (ifp->if_flags & IFF_SIMPLEX) &&
383 ((t = pf_find_mtag(m)) == NULL || !t->routed)) {
384 struct mbuf *n;
385
386 /*
387 * Because if_simloop() modifies the packet, we need a
388 * writable copy through m_dup() instead of a readonly
389 * one as m_copy[m] would give us. The alternative would
390 * be to modify if_simloop() to handle the readonly mbuf,
391 * but performancewise it is mostly equivalent (trading
392 * extra data copying vs. extra locking).
393 *
394 * XXX This is a local workaround. A number of less
395 * often used kernel parts suffer from the same bug.
396 * See PR kern/105943 for a proposed general solution.
397 */
398 if ((n = m_dup(m, M_NOWAIT)) != NULL) {
399 update_mbuf_csumflags(m, n);
400 (void)if_simloop(ifp, n, RO_GET_FAMILY(ro, dst), hlen);
401 } else
402 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
403 }
404
405 /*
406 * Bridges require special output handling.
407 */
408 if (ifp->if_bridge) {
409 BRIDGE_OUTPUT(ifp, m, error);
410 return (error);
411 }
412
413 #if defined(INET) || defined(INET6)
414 if (ifp->if_carp &&
415 (error = (*carp_output_p)(ifp, m, dst)))
416 goto bad;
417 #endif
418
419 /* Handle ng_ether(4) processing, if any */
420 if (ifp->if_l2com != NULL) {
421 KASSERT(ng_ether_output_p != NULL,
422 ("ng_ether_output_p is NULL"));
423 if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
424 bad: if (m != NULL)
425 m_freem(m);
426 return (error);
427 }
428 if (m == NULL)
429 return (0);
430 }
431
432 /* Continue with link-layer output */
433 return ether_output_frame(ifp, m);
434 }
435
436 static bool
ether_set_pcp(struct mbuf ** mp,struct ifnet * ifp,uint8_t pcp)437 ether_set_pcp(struct mbuf **mp, struct ifnet *ifp, uint8_t pcp)
438 {
439 struct ether_8021q_tag qtag;
440 struct ether_header *eh;
441
442 eh = mtod(*mp, struct ether_header *);
443 if (eh->ether_type == htons(ETHERTYPE_VLAN) ||
444 eh->ether_type == htons(ETHERTYPE_QINQ)) {
445 (*mp)->m_flags &= ~M_VLANTAG;
446 return (true);
447 }
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 */
464 int
ether_output_frame(struct ifnet * ifp,struct mbuf * m)465 ether_output_frame(struct ifnet *ifp, struct mbuf *m)
466 {
467 if (ether_do_pcp(ifp, m) && !ether_set_pcp(&m, ifp, ifp->if_pcp))
468 return (0);
469
470 if (PFIL_HOOKED_OUT(V_link_pfil_head))
471 switch (pfil_mbuf_out(V_link_pfil_head, &m, ifp, NULL)) {
472 case PFIL_DROPPED:
473 return (EACCES);
474 case PFIL_CONSUMED:
475 return (0);
476 }
477
478 /*
479 * Queue message on interface, update output statistics if successful,
480 * and start output if interface not yet active.
481 *
482 * If KMSAN is enabled, use it to verify that the data does not contain
483 * any uninitialized bytes.
484 */
485 kmsan_check_mbuf(m, "ether_output");
486 return ((ifp->if_transmit)(ifp, m));
487 }
488
489 /*
490 * Process a received Ethernet packet; the packet is in the
491 * mbuf chain m with the ethernet header at the front.
492 */
493 static void
ether_input_internal(struct ifnet * ifp,struct mbuf * m)494 ether_input_internal(struct ifnet *ifp, struct mbuf *m)
495 {
496 struct ether_header *eh;
497 u_short etype;
498
499 if ((ifp->if_flags & IFF_UP) == 0) {
500 m_freem(m);
501 return;
502 }
503 #ifdef DIAGNOSTIC
504 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
505 if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n");
506 m_freem(m);
507 return;
508 }
509 #endif
510 if (__predict_false(m->m_len < ETHER_HDR_LEN)) {
511 /* Drivers should pullup and ensure the mbuf is valid */
512 if_printf(ifp, "discard frame w/o leading ethernet "
513 "header (len %d pkt len %d)\n",
514 m->m_len, m->m_pkthdr.len);
515 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
516 m_freem(m);
517 return;
518 }
519 eh = mtod(m, struct ether_header *);
520 etype = ntohs(eh->ether_type);
521 random_harvest_queue_ether(m, sizeof(*m));
522
523 CURVNET_SET_QUIET(ifp->if_vnet);
524
525 if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
526 if (ETHER_IS_BROADCAST(eh->ether_dhost))
527 m->m_flags |= M_BCAST;
528 else
529 m->m_flags |= M_MCAST;
530 if_inc_counter(ifp, IFCOUNTER_IMCASTS, 1);
531 }
532
533 #ifdef MAC
534 /*
535 * Tag the mbuf with an appropriate MAC label before any other
536 * consumers can get to it.
537 */
538 mac_ifnet_create_mbuf(ifp, m);
539 #endif
540
541 /*
542 * Give bpf a chance at the packet.
543 */
544 ETHER_BPF_MTAP(ifp, m);
545
546 if (!(ifp->if_capenable & IFCAP_HWSTATS))
547 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
548
549 /* Allow monitor mode to claim this frame, after stats are updated. */
550 if (ifp->if_flags & IFF_MONITOR) {
551 m_freem(m);
552 CURVNET_RESTORE();
553 return;
554 }
555
556 /* Handle input from a lagg(4) port */
557 if (ifp->if_type == IFT_IEEE8023ADLAG) {
558 KASSERT(lagg_input_ethernet_p != NULL,
559 ("%s: if_lagg not loaded!", __func__));
560 m = (*lagg_input_ethernet_p)(ifp, m);
561 if (m != NULL)
562 ifp = m->m_pkthdr.rcvif;
563 else {
564 CURVNET_RESTORE();
565 return;
566 }
567 }
568
569 /*
570 * If the hardware did not process an 802.1Q tag, do this now,
571 * to allow 802.1P priority frames to be passed to the main input
572 * path correctly.
573 */
574 if ((m->m_flags & M_VLANTAG) == 0 &&
575 ((etype == ETHERTYPE_VLAN) || (etype == ETHERTYPE_QINQ))) {
576 struct ether_vlan_header *evl;
577
578 if (m->m_len < sizeof(*evl) &&
579 (m = m_pullup(m, sizeof(*evl))) == NULL) {
580 #ifdef DIAGNOSTIC
581 if_printf(ifp, "cannot pullup VLAN header\n");
582 #endif
583 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
584 CURVNET_RESTORE();
585 return;
586 }
587
588 evl = mtod(m, struct ether_vlan_header *);
589 m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag);
590 m->m_flags |= M_VLANTAG;
591
592 bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN,
593 ETHER_HDR_LEN - ETHER_TYPE_LEN);
594 m_adj(m, ETHER_VLAN_ENCAP_LEN);
595 eh = mtod(m, struct ether_header *);
596 }
597
598 M_SETFIB(m, ifp->if_fib);
599
600 /* Allow ng_ether(4) to claim this frame. */
601 if (ifp->if_l2com != NULL) {
602 KASSERT(ng_ether_input_p != NULL,
603 ("%s: ng_ether_input_p is NULL", __func__));
604 m->m_flags &= ~M_PROMISC;
605 (*ng_ether_input_p)(ifp, &m);
606 if (m == NULL) {
607 CURVNET_RESTORE();
608 return;
609 }
610 eh = mtod(m, struct ether_header *);
611 }
612
613 /*
614 * Allow if_bridge(4) to claim this frame.
615 *
616 * The BRIDGE_INPUT() macro will update ifp if the bridge changed it
617 * and the frame should be delivered locally.
618 *
619 * If M_BRIDGE_INJECT is set, the packet was received directly by the
620 * bridge via netmap, so "ifp" is the bridge itself and the packet
621 * should be re-examined.
622 */
623 if (ifp->if_bridge != NULL || (m->m_flags & M_BRIDGE_INJECT) != 0) {
624 m->m_flags &= ~M_PROMISC;
625 BRIDGE_INPUT(ifp, m);
626 if (m == NULL) {
627 CURVNET_RESTORE();
628 return;
629 }
630 eh = mtod(m, struct ether_header *);
631 }
632
633 #if defined(INET) || defined(INET6)
634 /*
635 * Clear M_PROMISC on frame so that carp(4) will see it when the
636 * mbuf flows up to Layer 3.
637 * FreeBSD's implementation of carp(4) uses the inprotosw
638 * to dispatch IPPROTO_CARP. carp(4) also allocates its own
639 * Ethernet addresses of the form 00:00:5e:00:01:xx, which
640 * is outside the scope of the M_PROMISC test below.
641 * TODO: Maintain a hash table of ethernet addresses other than
642 * ether_dhost which may be active on this ifp.
643 */
644 if (ifp->if_carp && (*carp_forus_p)(ifp, eh->ether_dhost)) {
645 m->m_flags &= ~M_PROMISC;
646 } else
647 #endif
648 {
649 /*
650 * If the frame received was not for our MAC address, set the
651 * M_PROMISC flag on the mbuf chain. The frame may need to
652 * be seen by the rest of the Ethernet input path in case of
653 * re-entry (e.g. bridge, vlan, netgraph) but should not be
654 * seen by upper protocol layers.
655 */
656 if (!ETHER_IS_MULTICAST(eh->ether_dhost) &&
657 memcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0)
658 m->m_flags |= M_PROMISC;
659 }
660
661 ether_demux(ifp, m);
662 CURVNET_RESTORE();
663 }
664
665 /*
666 * Ethernet input dispatch; by default, direct dispatch here regardless of
667 * global configuration. However, if RSS is enabled, hook up RSS affinity
668 * so that when deferred or hybrid dispatch is enabled, we can redistribute
669 * load based on RSS.
670 *
671 * XXXRW: Would be nice if the ifnet passed up a flag indicating whether or
672 * not it had already done work distribution via multi-queue. Then we could
673 * direct dispatch in the event load balancing was already complete and
674 * handle the case of interfaces with different capabilities better.
675 *
676 * XXXRW: Sort of want an M_DISTRIBUTED flag to avoid multiple distributions
677 * at multiple layers?
678 *
679 * XXXRW: For now, enable all this only if RSS is compiled in, although it
680 * works fine without RSS. Need to characterise the performance overhead
681 * of the detour through the netisr code in the event the result is always
682 * direct dispatch.
683 */
684 static void
ether_nh_input(struct mbuf * m)685 ether_nh_input(struct mbuf *m)
686 {
687
688 M_ASSERTPKTHDR(m);
689 KASSERT(m->m_pkthdr.rcvif != NULL,
690 ("%s: NULL interface pointer", __func__));
691 ether_input_internal(m->m_pkthdr.rcvif, m);
692 }
693
694 static struct netisr_handler ether_nh = {
695 .nh_name = "ether",
696 .nh_handler = ether_nh_input,
697 .nh_proto = NETISR_ETHER,
698 #ifdef RSS
699 .nh_policy = NETISR_POLICY_CPU,
700 .nh_dispatch = NETISR_DISPATCH_DIRECT,
701 .nh_m2cpuid = rss_m2cpuid,
702 #else
703 .nh_policy = NETISR_POLICY_SOURCE,
704 .nh_dispatch = NETISR_DISPATCH_DIRECT,
705 #endif
706 };
707
708 static void
ether_init(__unused void * arg)709 ether_init(__unused void *arg)
710 {
711
712 netisr_register(ðer_nh);
713 }
714 SYSINIT(ether, SI_SUB_INIT_IF, SI_ORDER_ANY, ether_init, NULL);
715
716 static void
vnet_ether_init(const __unused void * arg)717 vnet_ether_init(const __unused void *arg)
718 {
719 struct pfil_head_args args;
720
721 args.pa_version = PFIL_VERSION;
722 args.pa_flags = PFIL_IN | PFIL_OUT;
723 args.pa_type = PFIL_TYPE_ETHERNET;
724 args.pa_headname = PFIL_ETHER_NAME;
725 V_link_pfil_head = pfil_head_register(&args);
726
727 #ifdef VIMAGE
728 netisr_register_vnet(ðer_nh);
729 #endif
730 }
731 VNET_SYSINIT(vnet_ether_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
732 vnet_ether_init, NULL);
733
734 #ifdef VIMAGE
735 static void
vnet_ether_pfil_destroy(const __unused void * arg)736 vnet_ether_pfil_destroy(const __unused void *arg)
737 {
738
739 pfil_head_unregister(V_link_pfil_head);
740 }
741 VNET_SYSUNINIT(vnet_ether_pfil_uninit, SI_SUB_PROTO_PFIL, SI_ORDER_ANY,
742 vnet_ether_pfil_destroy, NULL);
743
744 static void
vnet_ether_destroy(__unused void * arg)745 vnet_ether_destroy(__unused void *arg)
746 {
747
748 netisr_unregister_vnet(ðer_nh);
749 }
750 VNET_SYSUNINIT(vnet_ether_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
751 vnet_ether_destroy, NULL);
752 #endif
753
754 static void
ether_input(struct ifnet * ifp,struct mbuf * m)755 ether_input(struct ifnet *ifp, struct mbuf *m)
756 {
757 struct epoch_tracker et;
758 struct mbuf *mn;
759 bool needs_epoch;
760
761 needs_epoch = (ifp->if_flags & IFF_NEEDSEPOCH);
762 #ifdef INVARIANTS
763 /*
764 * This temporary code is here to prevent epoch unaware and unmarked
765 * drivers to panic the system. Once all drivers are taken care of,
766 * the whole INVARIANTS block should go away.
767 */
768 if (!needs_epoch && !in_epoch(net_epoch_preempt)) {
769 static bool printedonce;
770
771 needs_epoch = true;
772 if (!printedonce) {
773 printedonce = true;
774 if_printf(ifp, "called %s w/o net epoch! "
775 "PLEASE file a bug report.", __func__);
776 #ifdef KDB
777 kdb_backtrace();
778 #endif
779 }
780 }
781 #endif
782
783 /*
784 * The drivers are allowed to pass in a chain of packets linked with
785 * m_nextpkt. We split them up into separate packets here and pass
786 * them up. This allows the drivers to amortize the receive lock.
787 */
788 CURVNET_SET_QUIET(ifp->if_vnet);
789 if (__predict_false(needs_epoch))
790 NET_EPOCH_ENTER(et);
791 while (m) {
792 mn = m->m_nextpkt;
793 m->m_nextpkt = NULL;
794
795 /*
796 * We will rely on rcvif being set properly in the deferred
797 * context, so assert it is correct here.
798 */
799 MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
800 KASSERT(m->m_pkthdr.rcvif == ifp, ("%s: ifnet mismatch m %p "
801 "rcvif %p ifp %p", __func__, m, m->m_pkthdr.rcvif, ifp));
802 netisr_dispatch(NETISR_ETHER, m);
803 m = mn;
804 }
805 if (__predict_false(needs_epoch))
806 NET_EPOCH_EXIT(et);
807 CURVNET_RESTORE();
808 }
809
810 /*
811 * Upper layer processing for a received Ethernet packet.
812 */
813 void
ether_demux(struct ifnet * ifp,struct mbuf * m)814 ether_demux(struct ifnet *ifp, struct mbuf *m)
815 {
816 struct ether_header *eh;
817 int i, isr;
818 u_short ether_type;
819
820 NET_EPOCH_ASSERT();
821 KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__));
822
823 /* Do not grab PROMISC frames in case we are re-entered. */
824 if (PFIL_HOOKED_IN(V_link_pfil_head) && !(m->m_flags & M_PROMISC)) {
825 i = pfil_mbuf_in(V_link_pfil_head, &m, ifp, NULL);
826 if (i != PFIL_PASS)
827 return;
828 }
829
830 eh = mtod(m, struct ether_header *);
831 ether_type = ntohs(eh->ether_type);
832
833 /*
834 * If this frame has a VLAN tag other than 0, call vlan_input()
835 * if its module is loaded. Otherwise, drop.
836 */
837 if ((m->m_flags & M_VLANTAG) &&
838 EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) {
839 if (ifp->if_vlantrunk == NULL) {
840 if_inc_counter(ifp, IFCOUNTER_NOPROTO, 1);
841 m_freem(m);
842 return;
843 }
844 KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!",
845 __func__));
846 /* Clear before possibly re-entering ether_input(). */
847 m->m_flags &= ~M_PROMISC;
848 (*vlan_input_p)(ifp, m);
849 return;
850 }
851
852 /*
853 * Pass promiscuously received frames to the upper layer if the user
854 * requested this by setting IFF_PPROMISC. Otherwise, drop them.
855 */
856 if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) {
857 m_freem(m);
858 return;
859 }
860
861 /*
862 * Reset layer specific mbuf flags to avoid confusing upper layers.
863 */
864 m->m_flags &= ~M_VLANTAG;
865 m_clrprotoflags(m);
866
867 /*
868 * Dispatch frame to upper layer.
869 */
870 switch (ether_type) {
871 #ifdef INET
872 case ETHERTYPE_IP:
873 isr = NETISR_IP;
874 break;
875
876 case ETHERTYPE_ARP:
877 if (ifp->if_flags & IFF_NOARP) {
878 /* Discard packet if ARP is disabled on interface */
879 m_freem(m);
880 return;
881 }
882 isr = NETISR_ARP;
883 break;
884 #endif
885 #ifdef INET6
886 case ETHERTYPE_IPV6:
887 isr = NETISR_IPV6;
888 break;
889 #endif
890 default:
891 goto discard;
892 }
893
894 /* Strip off Ethernet header. */
895 m_adj(m, ETHER_HDR_LEN);
896
897 netisr_dispatch(isr, m);
898 return;
899
900 discard:
901 /*
902 * Packet is to be discarded. If netgraph is present,
903 * hand the packet to it for last chance processing;
904 * otherwise dispose of it.
905 */
906 if (ifp->if_l2com != NULL) {
907 KASSERT(ng_ether_input_orphan_p != NULL,
908 ("ng_ether_input_orphan_p is NULL"));
909 (*ng_ether_input_orphan_p)(ifp, m);
910 return;
911 }
912 m_freem(m);
913 }
914
915 /*
916 * Convert Ethernet address to printable (loggable) representation.
917 * This routine is for compatibility; it's better to just use
918 *
919 * printf("%6D", <pointer to address>, ":");
920 *
921 * since there's no static buffer involved.
922 */
923 char *
ether_sprintf(const u_char * ap)924 ether_sprintf(const u_char *ap)
925 {
926 static char etherbuf[18];
927 snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":");
928 return (etherbuf);
929 }
930
931 /*
932 * Perform common duties while attaching to interface list
933 */
934 void
ether_ifattach(struct ifnet * ifp,const u_int8_t * lla)935 ether_ifattach(struct ifnet *ifp, const u_int8_t *lla)
936 {
937 int i;
938 struct ifaddr *ifa;
939 struct sockaddr_dl *sdl;
940
941 ifp->if_addrlen = ETHER_ADDR_LEN;
942 ifp->if_hdrlen = (ifp->if_capabilities & IFCAP_VLAN_MTU) != 0 ?
943 ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN : ETHER_HDR_LEN;
944 ifp->if_mtu = ETHERMTU;
945 if_attach(ifp);
946 ifp->if_output = ether_output;
947 ifp->if_input = ether_input;
948 ifp->if_resolvemulti = ether_resolvemulti;
949 ifp->if_requestencap = ether_requestencap;
950 if (ifp->if_baudrate == 0)
951 ifp->if_baudrate = IF_Mbps(10); /* just a default */
952 ifp->if_broadcastaddr = etherbroadcastaddr;
953
954 ifa = ifp->if_addr;
955 KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
956 sdl = (struct sockaddr_dl *)ifa->ifa_addr;
957 sdl->sdl_type = IFT_ETHER;
958 sdl->sdl_alen = ifp->if_addrlen;
959 bcopy(lla, LLADDR(sdl), ifp->if_addrlen);
960
961 if (ifp->if_hw_addr != NULL)
962 bcopy(lla, ifp->if_hw_addr, ifp->if_addrlen);
963
964 bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
965
966 /* Announce Ethernet MAC address if non-zero. */
967 for (i = 0; i < ifp->if_addrlen; i++)
968 if (lla[i] != 0)
969 break;
970 if (i != ifp->if_addrlen)
971 if_printf(ifp, "Ethernet address: %6D\n", lla, ":");
972
973 uuid_ether_add(LLADDR(sdl));
974
975 /* Add necessary bits are setup; announce it now. */
976 EVENTHANDLER_INVOKE(ether_ifattach_event, ifp);
977 if (IS_DEFAULT_VNET(curvnet))
978 devctl_notify("ETHERNET", ifp->if_xname, "IFATTACH", NULL);
979 }
980
981 /*
982 * Perform common duties while detaching an Ethernet interface
983 */
984 void
ether_ifdetach(struct ifnet * ifp)985 ether_ifdetach(struct ifnet *ifp)
986 {
987 struct sockaddr_dl *sdl;
988
989 sdl = (struct sockaddr_dl *)(ifp->if_addr->ifa_addr);
990 uuid_ether_del(LLADDR(sdl));
991
992 bpfdetach(ifp);
993 if_detach(ifp);
994 }
995
996 SYSCTL_DECL(_net_link);
997 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
998 "Ethernet");
999
1000 #if 0
1001 /*
1002 * This is for reference. We have a table-driven version
1003 * of the little-endian crc32 generator, which is faster
1004 * than the double-loop.
1005 */
1006 uint32_t
1007 ether_crc32_le(const uint8_t *buf, size_t len)
1008 {
1009 size_t i;
1010 uint32_t crc;
1011 int bit;
1012 uint8_t data;
1013
1014 crc = 0xffffffff; /* initial value */
1015
1016 for (i = 0; i < len; i++) {
1017 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
1018 carry = (crc ^ data) & 1;
1019 crc >>= 1;
1020 if (carry)
1021 crc = (crc ^ ETHER_CRC_POLY_LE);
1022 }
1023 }
1024
1025 return (crc);
1026 }
1027 #else
1028 uint32_t
ether_crc32_le(const uint8_t * buf,size_t len)1029 ether_crc32_le(const uint8_t *buf, size_t len)
1030 {
1031 static const uint32_t crctab[] = {
1032 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
1033 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
1034 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
1035 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
1036 };
1037 size_t i;
1038 uint32_t crc;
1039
1040 crc = 0xffffffff; /* initial value */
1041
1042 for (i = 0; i < len; i++) {
1043 crc ^= buf[i];
1044 crc = (crc >> 4) ^ crctab[crc & 0xf];
1045 crc = (crc >> 4) ^ crctab[crc & 0xf];
1046 }
1047
1048 return (crc);
1049 }
1050 #endif
1051
1052 uint32_t
ether_crc32_be(const uint8_t * buf,size_t len)1053 ether_crc32_be(const uint8_t *buf, size_t len)
1054 {
1055 size_t i;
1056 uint32_t crc, carry;
1057 int bit;
1058 uint8_t data;
1059
1060 crc = 0xffffffff; /* initial value */
1061
1062 for (i = 0; i < len; i++) {
1063 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
1064 carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01);
1065 crc <<= 1;
1066 if (carry)
1067 crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
1068 }
1069 }
1070
1071 return (crc);
1072 }
1073
1074 int
ether_ioctl(struct ifnet * ifp,u_long command,caddr_t data)1075 ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
1076 {
1077 struct ifaddr *ifa = (struct ifaddr *) data;
1078 struct ifreq *ifr = (struct ifreq *) data;
1079 int error = 0;
1080
1081 switch (command) {
1082 case SIOCSIFADDR:
1083 ifp->if_flags |= IFF_UP;
1084
1085 switch (ifa->ifa_addr->sa_family) {
1086 #ifdef INET
1087 case AF_INET:
1088 ifp->if_init(ifp->if_softc); /* before arpwhohas */
1089 arp_ifinit(ifp, ifa);
1090 break;
1091 #endif
1092 default:
1093 ifp->if_init(ifp->if_softc);
1094 break;
1095 }
1096 break;
1097
1098 case SIOCGIFADDR:
1099 bcopy(IF_LLADDR(ifp), &ifr->ifr_addr.sa_data[0],
1100 ETHER_ADDR_LEN);
1101 break;
1102
1103 case SIOCSIFMTU:
1104 /*
1105 * Set the interface MTU.
1106 */
1107 if (ifr->ifr_mtu > ETHERMTU) {
1108 error = EINVAL;
1109 } else {
1110 ifp->if_mtu = ifr->ifr_mtu;
1111 }
1112 break;
1113
1114 case SIOCSLANPCP:
1115 error = priv_check(curthread, PRIV_NET_SETLANPCP);
1116 if (error != 0)
1117 break;
1118 if (ifr->ifr_lan_pcp > 7 &&
1119 ifr->ifr_lan_pcp != IFNET_PCP_NONE) {
1120 error = EINVAL;
1121 } else {
1122 ifp->if_pcp = ifr->ifr_lan_pcp;
1123 /* broadcast event about PCP change */
1124 EVENTHANDLER_INVOKE(ifnet_event, ifp, IFNET_EVENT_PCP);
1125 }
1126 break;
1127
1128 case SIOCGLANPCP:
1129 ifr->ifr_lan_pcp = ifp->if_pcp;
1130 break;
1131
1132 default:
1133 error = EINVAL; /* XXX netbsd has ENOTTY??? */
1134 break;
1135 }
1136 return (error);
1137 }
1138
1139 static int
ether_resolvemulti(struct ifnet * ifp,struct sockaddr ** llsa,struct sockaddr * sa)1140 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
1141 struct sockaddr *sa)
1142 {
1143 struct sockaddr_dl *sdl;
1144 #ifdef INET
1145 struct sockaddr_in *sin;
1146 #endif
1147 #ifdef INET6
1148 struct sockaddr_in6 *sin6;
1149 #endif
1150 u_char *e_addr;
1151
1152 switch(sa->sa_family) {
1153 case AF_LINK:
1154 /*
1155 * No mapping needed. Just check that it's a valid MC address.
1156 */
1157 sdl = (struct sockaddr_dl *)sa;
1158 e_addr = LLADDR(sdl);
1159 if (!ETHER_IS_MULTICAST(e_addr))
1160 return EADDRNOTAVAIL;
1161 *llsa = NULL;
1162 return 0;
1163
1164 #ifdef INET
1165 case AF_INET:
1166 sin = (struct sockaddr_in *)sa;
1167 if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
1168 return EADDRNOTAVAIL;
1169 sdl = link_init_sdl(ifp, *llsa, IFT_ETHER);
1170 sdl->sdl_alen = ETHER_ADDR_LEN;
1171 e_addr = LLADDR(sdl);
1172 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
1173 *llsa = (struct sockaddr *)sdl;
1174 return 0;
1175 #endif
1176 #ifdef INET6
1177 case AF_INET6:
1178 sin6 = (struct sockaddr_in6 *)sa;
1179 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
1180 /*
1181 * An IP6 address of 0 means listen to all
1182 * of the Ethernet multicast address used for IP6.
1183 * (This is used for multicast routers.)
1184 */
1185 ifp->if_flags |= IFF_ALLMULTI;
1186 *llsa = NULL;
1187 return 0;
1188 }
1189 if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
1190 return EADDRNOTAVAIL;
1191 sdl = link_init_sdl(ifp, *llsa, IFT_ETHER);
1192 sdl->sdl_alen = ETHER_ADDR_LEN;
1193 e_addr = LLADDR(sdl);
1194 ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
1195 *llsa = (struct sockaddr *)sdl;
1196 return 0;
1197 #endif
1198
1199 default:
1200 /*
1201 * Well, the text isn't quite right, but it's the name
1202 * that counts...
1203 */
1204 return EAFNOSUPPORT;
1205 }
1206 }
1207
1208 static moduledata_t ether_mod = {
1209 .name = "ether",
1210 };
1211
1212 void
ether_vlan_mtap(struct bpf_if * bp,struct mbuf * m,void * data,u_int dlen)1213 ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen)
1214 {
1215 struct ether_vlan_header vlan;
1216 struct mbuf mv, mb;
1217
1218 KASSERT((m->m_flags & M_VLANTAG) != 0,
1219 ("%s: vlan information not present", __func__));
1220 KASSERT(m->m_len >= sizeof(struct ether_header),
1221 ("%s: mbuf not large enough for header", __func__));
1222 bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header));
1223 vlan.evl_proto = vlan.evl_encap_proto;
1224 vlan.evl_encap_proto = htons(ETHERTYPE_VLAN);
1225 vlan.evl_tag = htons(m->m_pkthdr.ether_vtag);
1226 m->m_len -= sizeof(struct ether_header);
1227 m->m_data += sizeof(struct ether_header);
1228 /*
1229 * If a data link has been supplied by the caller, then we will need to
1230 * re-create a stack allocated mbuf chain with the following structure:
1231 *
1232 * (1) mbuf #1 will contain the supplied data link
1233 * (2) mbuf #2 will contain the vlan header
1234 * (3) mbuf #3 will contain the original mbuf's packet data
1235 *
1236 * Otherwise, submit the packet and vlan header via bpf_mtap2().
1237 */
1238 if (data != NULL) {
1239 mv.m_next = m;
1240 mv.m_data = (caddr_t)&vlan;
1241 mv.m_len = sizeof(vlan);
1242 mb.m_next = &mv;
1243 mb.m_data = data;
1244 mb.m_len = dlen;
1245 bpf_mtap(bp, &mb);
1246 } else
1247 bpf_mtap2(bp, &vlan, sizeof(vlan), m);
1248 m->m_len += sizeof(struct ether_header);
1249 m->m_data -= sizeof(struct ether_header);
1250 }
1251
1252 struct mbuf *
ether_vlanencap_proto(struct mbuf * m,uint16_t tag,uint16_t proto)1253 ether_vlanencap_proto(struct mbuf *m, uint16_t tag, uint16_t proto)
1254 {
1255 struct ether_vlan_header *evl;
1256
1257 M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
1258 if (m == NULL)
1259 return (NULL);
1260 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */
1261
1262 if (m->m_len < sizeof(*evl)) {
1263 m = m_pullup(m, sizeof(*evl));
1264 if (m == NULL)
1265 return (NULL);
1266 }
1267
1268 /*
1269 * Transform the Ethernet header into an Ethernet header
1270 * with 802.1Q encapsulation.
1271 */
1272 evl = mtod(m, struct ether_vlan_header *);
1273 bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN,
1274 (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
1275 evl->evl_encap_proto = htons(proto);
1276 evl->evl_tag = htons(tag);
1277 return (m);
1278 }
1279
1280 void
ether_bpf_mtap_if(struct ifnet * ifp,struct mbuf * m)1281 ether_bpf_mtap_if(struct ifnet *ifp, struct mbuf *m)
1282 {
1283 if (bpf_peers_present(ifp->if_bpf)) {
1284 M_ASSERTVALID(m);
1285 if ((m->m_flags & M_VLANTAG) != 0)
1286 ether_vlan_mtap(ifp->if_bpf, m, NULL, 0);
1287 else
1288 bpf_mtap(ifp->if_bpf, m);
1289 }
1290 }
1291
1292 static SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1293 "IEEE 802.1Q VLAN");
1294 static SYSCTL_NODE(_net_link_vlan, PF_LINK, link,
1295 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1296 "for consistency");
1297
1298 VNET_DEFINE_STATIC(int, soft_pad);
1299 #define V_soft_pad VNET(soft_pad)
1300 SYSCTL_INT(_net_link_vlan, OID_AUTO, soft_pad, CTLFLAG_RW | CTLFLAG_VNET,
1301 &VNET_NAME(soft_pad), 0,
1302 "pad short frames before tagging");
1303
1304 /*
1305 * For now, make preserving PCP via an mbuf tag optional, as it increases
1306 * per-packet memory allocations and frees. In the future, it would be
1307 * preferable to reuse ether_vtag for this, or similar.
1308 */
1309 VNET_DEFINE(int, vlan_mtag_pcp) = 0;
1310 #define V_vlan_mtag_pcp VNET(vlan_mtag_pcp)
1311 SYSCTL_INT(_net_link_vlan, OID_AUTO, mtag_pcp, CTLFLAG_RW | CTLFLAG_VNET,
1312 &VNET_NAME(vlan_mtag_pcp), 0,
1313 "Retain VLAN PCP information as packets are passed up the stack");
1314
1315 static inline bool
ether_do_pcp(struct ifnet * ifp,struct mbuf * m)1316 ether_do_pcp(struct ifnet *ifp, struct mbuf *m)
1317 {
1318 if (ifp->if_type == IFT_L2VLAN)
1319 return (false);
1320 if (ifp->if_pcp != IFNET_PCP_NONE || (m->m_flags & M_VLANTAG) != 0)
1321 return (true);
1322 if (V_vlan_mtag_pcp &&
1323 m_tag_locate(m, MTAG_8021Q, MTAG_8021Q_PCP_OUT, NULL) != NULL)
1324 return (true);
1325 return (false);
1326 }
1327
1328 bool
ether_8021q_frame(struct mbuf ** mp,struct ifnet * ife,struct ifnet * p,const struct ether_8021q_tag * qtag)1329 ether_8021q_frame(struct mbuf **mp, struct ifnet *ife, struct ifnet *p,
1330 const struct ether_8021q_tag *qtag)
1331 {
1332 struct m_tag *mtag;
1333 int n;
1334 uint16_t tag;
1335 uint8_t pcp = qtag->pcp;
1336 static const char pad[8]; /* just zeros */
1337
1338 /*
1339 * Pad the frame to the minimum size allowed if told to.
1340 * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
1341 * paragraph C.4.4.3.b. It can help to work around buggy
1342 * bridges that violate paragraph C.4.4.3.a from the same
1343 * document, i.e., fail to pad short frames after untagging.
1344 * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
1345 * untagging it will produce a 62-byte frame, which is a runt
1346 * and requires padding. There are VLAN-enabled network
1347 * devices that just discard such runts instead or mishandle
1348 * them somehow.
1349 */
1350 if (V_soft_pad && p->if_type == IFT_ETHER) {
1351 for (n = ETHERMIN + ETHER_HDR_LEN - (*mp)->m_pkthdr.len;
1352 n > 0; n -= sizeof(pad)) {
1353 if (!m_append(*mp, min(n, sizeof(pad)), pad))
1354 break;
1355 }
1356 if (n > 0) {
1357 m_freem(*mp);
1358 *mp = NULL;
1359 if_printf(ife, "cannot pad short frame");
1360 return (false);
1361 }
1362 }
1363
1364 /*
1365 * If PCP is set in mbuf, use it
1366 */
1367 if ((*mp)->m_flags & M_VLANTAG) {
1368 pcp = EVL_PRIOFTAG((*mp)->m_pkthdr.ether_vtag);
1369 }
1370
1371 /*
1372 * If underlying interface can do VLAN tag insertion itself,
1373 * just pass the packet along. However, we need some way to
1374 * tell the interface where the packet came from so that it
1375 * knows how to find the VLAN tag to use, so we attach a
1376 * packet tag that holds it.
1377 */
1378 if (V_vlan_mtag_pcp && (mtag = m_tag_locate(*mp, MTAG_8021Q,
1379 MTAG_8021Q_PCP_OUT, NULL)) != NULL)
1380 tag = EVL_MAKETAG(qtag->vid, *(uint8_t *)(mtag + 1), 0);
1381 else
1382 tag = EVL_MAKETAG(qtag->vid, pcp, 0);
1383 if ((p->if_capenable & IFCAP_VLAN_HWTAGGING) &&
1384 (qtag->proto == ETHERTYPE_VLAN)) {
1385 (*mp)->m_pkthdr.ether_vtag = tag;
1386 (*mp)->m_flags |= M_VLANTAG;
1387 } else {
1388 *mp = ether_vlanencap_proto(*mp, tag, qtag->proto);
1389 if (*mp == NULL) {
1390 if_printf(ife, "unable to prepend 802.1Q header");
1391 return (false);
1392 }
1393 (*mp)->m_flags &= ~M_VLANTAG;
1394 }
1395 return (true);
1396 }
1397
1398 /*
1399 * Allocate an address from the FreeBSD Foundation OUI. This uses a
1400 * cryptographic hash function on the containing jail's name, UUID and the
1401 * interface name to attempt to provide a unique but stable address.
1402 * Pseudo-interfaces which require a MAC address should use this function to
1403 * allocate non-locally-administered addresses.
1404 */
1405 void
ether_gen_addr_byname(const char * nameunit,struct ether_addr * hwaddr)1406 ether_gen_addr_byname(const char *nameunit, struct ether_addr *hwaddr)
1407 {
1408 SHA1_CTX ctx;
1409 char *buf;
1410 char uuid[HOSTUUIDLEN + 1];
1411 uint64_t addr;
1412 int i, sz;
1413 unsigned char digest[SHA1_RESULTLEN];
1414 char jailname[MAXHOSTNAMELEN];
1415
1416 getcredhostuuid(curthread->td_ucred, uuid, sizeof(uuid));
1417 if (strncmp(uuid, DEFAULT_HOSTUUID, sizeof(uuid)) == 0) {
1418 /* Fall back to a random mac address. */
1419 goto rando;
1420 }
1421
1422 /* If each (vnet) jail would also have a unique hostuuid this would not
1423 * be necessary. */
1424 getjailname(curthread->td_ucred, jailname, sizeof(jailname));
1425 sz = asprintf(&buf, M_TEMP, "%s-%s-%s", uuid, nameunit,
1426 jailname);
1427 if (sz < 0) {
1428 /* Fall back to a random mac address. */
1429 goto rando;
1430 }
1431
1432 SHA1Init(&ctx);
1433 SHA1Update(&ctx, buf, sz);
1434 SHA1Final(digest, &ctx);
1435 free(buf, M_TEMP);
1436
1437 addr = (digest[0] << 8) | digest[1] | OUI_FREEBSD_GENERATED_LOW;
1438 for (i = 0; i < ETHER_ADDR_LEN; ++i) {
1439 hwaddr->octet[i] = addr >> ((ETHER_ADDR_LEN - i - 1) * 8) &
1440 0xFF;
1441 }
1442
1443 return;
1444 rando:
1445 arc4rand(hwaddr, sizeof(*hwaddr), 0);
1446 /* Unicast */
1447 hwaddr->octet[0] &= 0xFE;
1448 /* Locally administered. */
1449 hwaddr->octet[0] |= 0x02;
1450 }
1451
1452 void
ether_gen_addr(struct ifnet * ifp,struct ether_addr * hwaddr)1453 ether_gen_addr(struct ifnet *ifp, struct ether_addr *hwaddr)
1454 {
1455 ether_gen_addr_byname(if_name(ifp), hwaddr);
1456 }
1457
1458 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
1459 MODULE_VERSION(ether, 1);
1460