2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
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13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93
33 * Ethernet address resolution protocol.
35 * add "inuse/lock" bit (or ref. count) along with valid bit
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
43 #include <sys/param.h>
44 #include <sys/kernel.h>
45 #include <sys/queue.h>
46 #include <sys/sysctl.h>
47 #include <sys/systm.h>
49 #include <sys/malloc.h>
51 #include <sys/socket.h>
52 #include <sys/syslog.h>
55 #include <net/if_dl.h>
56 #include <net/if_types.h>
57 #include <net/netisr.h>
58 #include <net/if_llc.h>
59 #include <net/ethernet.h>
60 #include <net/route.h>
63 #include <netinet/in.h>
64 #include <netinet/in_var.h>
65 #include <net/if_llatbl.h>
66 #include <netinet/if_ether.h>
67 #if defined(INET) || defined(INET6)
68 #include <netinet/ip_carp.h>
71 #include <net/if_arc.h>
72 #include <net/iso88025.h>
74 #include <security/mac/mac_framework.h>
76 #define SIN(s) ((struct sockaddr_in *)s)
77 #define SDL(s) ((struct sockaddr_dl *)s)
79 SYSCTL_DECL(_net_link_ether);
80 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
81 SYSCTL_NODE(_net_link_ether, PF_ARP, arp, CTLFLAG_RW, 0, "");
84 static VNET_DEFINE(int, arpt_keep) = (20*60); /* once resolved, good for 20
86 static VNET_DEFINE(int, arp_maxtries) = 5;
87 VNET_DEFINE(int, useloopback) = 1; /* use loopback interface for
89 static VNET_DEFINE(int, arp_proxyall) = 0;
90 static VNET_DEFINE(int, arpt_down) = 20; /* keep incomplete entries for
92 static VNET_DEFINE(struct arpstat, arpstat); /* ARP statistics, see if_arp.h */
94 #define V_arpt_keep VNET(arpt_keep)
95 #define V_arpt_down VNET(arpt_down)
96 #define V_arp_maxtries VNET(arp_maxtries)
97 #define V_arp_proxyall VNET(arp_proxyall)
98 #define V_arpstat VNET(arpstat)
100 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
101 &VNET_NAME(arpt_keep), 0,
102 "ARP entry lifetime in seconds");
103 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
104 &VNET_NAME(arp_maxtries), 0,
105 "ARP resolution attempts before returning error");
106 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
107 &VNET_NAME(useloopback), 0,
108 "Use the loopback interface for local traffic");
109 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
110 &VNET_NAME(arp_proxyall), 0,
111 "Enable proxy ARP for all suitable requests");
112 SYSCTL_VNET_STRUCT(_net_link_ether_arp, OID_AUTO, stats, CTLFLAG_RW,
113 &VNET_NAME(arpstat), arpstat,
114 "ARP statistics (struct arpstat, net/if_arp.h)");
116 static void arp_init(void);
117 void arprequest(struct ifnet *,
118 struct in_addr *, struct in_addr *, u_char *);
119 static void arpintr(struct mbuf *);
120 static void arptimer(void *);
122 static void in_arpinput(struct mbuf *);
125 static const struct netisr_handler arp_nh = {
127 .nh_handler = arpintr,
128 .nh_proto = NETISR_ARP,
129 .nh_policy = NETISR_POLICY_SOURCE,
133 void arp_ifscrub(struct ifnet *ifp, uint32_t addr);
136 * called by in_ifscrub to remove entry from the table when
137 * the interface goes away
140 arp_ifscrub(struct ifnet *ifp, uint32_t addr)
142 struct sockaddr_in addr4;
144 bzero((void *)&addr4, sizeof(addr4));
145 addr4.sin_len = sizeof(addr4);
146 addr4.sin_family = AF_INET;
147 addr4.sin_addr.s_addr = addr;
149 lla_lookup(LLTABLE(ifp), (LLE_DELETE | LLE_IFADDR),
150 (struct sockaddr *)&addr4);
151 IF_AFDATA_UNLOCK(ifp);
156 * Timeout routine. Age arp_tab entries periodically.
164 KASSERT(arg != NULL, ("%s: arg NULL", __func__));
165 lle = (struct llentry *)arg;
166 ifp = lle->lle_tbl->llt_ifp;
167 CURVNET_SET(ifp->if_vnet);
170 if (lle->la_flags & LLE_STATIC)
173 if (!callout_pending(&lle->la_timer) &&
174 callout_active(&lle->la_timer)) {
175 callout_stop(&lle->la_timer);
177 (void) llentry_free(lle);
178 ARPSTAT_INC(timeouts);
182 struct sockaddr *l3addr = L3_ADDR(lle);
184 "arptimer issue: %p, IPv4 address: \"%s\"\n", lle,
186 ((const struct sockaddr_in *)l3addr)->sin_addr));
190 IF_AFDATA_UNLOCK(ifp);
195 * Broadcast an ARP request. Caller specifies:
196 * - arp header source ip address
197 * - arp header target ip address
198 * - arp header source ethernet address
201 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip,
209 /* XXX don't believe this can happen (or explain why) */
211 * The caller did not supply a source address, try to find
212 * a compatible one among those assigned to this interface.
216 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
217 if (!ifa->ifa_addr ||
218 ifa->ifa_addr->sa_family != AF_INET)
220 sip = &SIN(ifa->ifa_addr)->sin_addr;
221 if (0 == ((sip->s_addr ^ tip->s_addr) &
222 SIN(ifa->ifa_netmask)->sin_addr.s_addr) )
223 break; /* found it. */
226 printf("%s: cannot find matching address\n", __func__);
231 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
233 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
234 2*ifp->if_data.ifi_addrlen;
235 m->m_pkthdr.len = m->m_len;
236 MH_ALIGN(m, m->m_len);
237 ah = mtod(m, struct arphdr *);
238 bzero((caddr_t)ah, m->m_len);
240 mac_netinet_arp_send(ifp, m);
242 ah->ar_pro = htons(ETHERTYPE_IP);
243 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
244 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
245 ah->ar_op = htons(ARPOP_REQUEST);
246 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
247 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
248 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
249 sa.sa_family = AF_ARP;
251 m->m_flags |= M_BCAST;
252 (*ifp->if_output)(ifp, m, &sa, NULL);
253 ARPSTAT_INC(txrequests);
257 * Resolve an IP address into an ethernet address.
259 * ifp is the interface we use
260 * rt0 is the route to the final destination (possibly useless)
261 * m is the mbuf. May be NULL if we don't have a packet.
262 * dst is the next hop,
263 * desten is where we want the address.
265 * On success, desten is filled in and the function returns 0;
266 * If the packet must be held pending resolution, we return EWOULDBLOCK
267 * On other errors, we return the corresponding error code.
268 * Note that m_freem() handles NULL.
271 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
272 struct sockaddr *dst, u_char *desten, struct llentry **lle)
274 struct llentry *la = 0;
280 if (m->m_flags & M_BCAST) {
283 ifp->if_broadcastaddr, ifp->if_addrlen);
286 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {
288 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
295 IF_AFDATA_RLOCK(ifp);
296 la = lla_lookup(LLTABLE(ifp), flags, dst);
297 IF_AFDATA_RUNLOCK(ifp);
298 if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0)
299 && ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) {
300 flags |= (LLE_CREATE | LLE_EXCLUSIVE);
301 IF_AFDATA_WLOCK(ifp);
302 la = lla_lookup(LLTABLE(ifp), flags, dst);
303 IF_AFDATA_WUNLOCK(ifp);
306 if (flags & LLE_CREATE)
308 "arpresolve: can't allocate llinfo for %s\n",
309 inet_ntoa(SIN(dst)->sin_addr));
314 if ((la->la_flags & LLE_VALID) &&
315 ((la->la_flags & LLE_STATIC) || la->la_expire > time_second)) {
316 bcopy(&la->ll_addr, desten, ifp->if_addrlen);
318 * If entry has an expiry time and it is approaching,
319 * see if we need to send an ARP request within this
320 * arpt_down interval.
322 if (!(la->la_flags & LLE_STATIC) &&
323 time_second + la->la_preempt > la->la_expire) {
324 arprequest(ifp, NULL,
325 &SIN(dst)->sin_addr, IF_LLADDR(ifp));
335 if (la->la_flags & LLE_STATIC) { /* should not happen! */
336 log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n",
337 inet_ntoa(SIN(dst)->sin_addr));
343 renew = (la->la_asked == 0 || la->la_expire != time_second);
344 if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) {
345 flags |= LLE_EXCLUSIVE;
350 * There is an arptab entry, but no ethernet address
351 * response yet. Replace the held mbuf with this
355 if (la->la_hold != NULL) {
356 m_freem(la->la_hold);
357 ARPSTAT_INC(dropped);
360 if (renew == 0 && (flags & LLE_EXCLUSIVE)) {
361 flags &= ~LLE_EXCLUSIVE;
367 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It
368 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
369 * if we have already sent arp_maxtries ARP requests. Retransmit the
370 * ARP request, but not faster than one request per second.
372 if (la->la_asked < V_arp_maxtries)
373 error = EWOULDBLOCK; /* First request. */
375 error = rt0 != NULL && (rt0->rt_flags & RTF_GATEWAY) ?
376 EHOSTUNREACH : EHOSTDOWN;
382 la->la_expire = time_second;
383 canceled = callout_reset(&la->la_timer, hz * V_arpt_down,
389 arprequest(ifp, NULL, &SIN(dst)->sin_addr,
394 if (flags & LLE_EXCLUSIVE)
402 * Common length and type checks are done here,
403 * then the protocol-specific routine is called.
406 arpintr(struct mbuf *m)
410 if (m->m_len < sizeof(struct arphdr) &&
411 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
412 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
415 ar = mtod(m, struct arphdr *);
417 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
418 ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
419 ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
420 ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
421 log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
422 (unsigned char *)&ar->ar_hrd, "");
427 if (m->m_len < arphdr_len(ar)) {
428 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
429 log(LOG_ERR, "arp: runt packet\n");
433 ar = mtod(m, struct arphdr *);
436 ARPSTAT_INC(received);
437 switch (ntohs(ar->ar_pro)) {
449 * ARP for Internet protocols on 10 Mb/s Ethernet.
450 * Algorithm is that given in RFC 826.
451 * In addition, a sanity check is performed on the sender
452 * protocol address, to catch impersonators.
453 * We no longer handle negotiations for use of trailer protocol:
454 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
455 * along with IP replies if we wanted trailers sent to us,
456 * and also sent them in response to IP replies.
457 * This allowed either end to announce the desire to receive
459 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
460 * but formerly didn't normally send requests.
462 static int log_arp_wrong_iface = 1;
463 static int log_arp_movements = 1;
464 static int log_arp_permanent_modify = 1;
466 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
467 &log_arp_wrong_iface, 0,
468 "log arp packets arriving on the wrong interface");
469 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
470 &log_arp_movements, 0,
471 "log arp replies from MACs different than the one in the cache");
472 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
473 &log_arp_permanent_modify, 0,
474 "log arp replies from MACs different than the one in the permanent arp entry");
478 in_arpinput(struct mbuf *m)
481 struct ifnet *ifp = m->m_pkthdr.rcvif;
482 struct llentry *la = NULL;
485 struct in_ifaddr *ia;
488 struct in_addr isaddr, itaddr, myaddr;
489 u_int8_t *enaddr = NULL;
492 int bridged = 0, is_bridge = 0;
494 struct sockaddr_in sin;
495 sin.sin_len = sizeof(struct sockaddr_in);
496 sin.sin_family = AF_INET;
497 sin.sin_addr.s_addr = 0;
501 if (ifp->if_type == IFT_BRIDGE)
504 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
505 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
506 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
510 ah = mtod(m, struct arphdr *);
511 op = ntohs(ah->ar_op);
512 (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
513 (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
515 if (op == ARPOP_REPLY)
516 ARPSTAT_INC(rxreplies);
519 * For a bridge, we want to check the address irrespective
520 * of the receive interface. (This will change slightly
521 * when we have clusters of interfaces).
522 * If the interface does not match, but the recieving interface
523 * is part of carp, we call carp_iamatch to see if this is a
524 * request for the virtual host ip.
525 * XXX: This is really ugly!
528 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
529 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
530 ia->ia_ifp == ifp) &&
531 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
532 ifa_ref(&ia->ia_ifa);
536 if (ifp->if_carp != NULL &&
537 (*carp_iamatch_p)(ifp, ia, &isaddr, &enaddr) &&
538 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
540 ifa_ref(&ia->ia_ifa);
545 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
546 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
547 ia->ia_ifp == ifp) &&
548 isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
549 ifa_ref(&ia->ia_ifa);
554 #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \
555 (ia->ia_ifp->if_bridge == ifp->if_softc && \
556 !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \
557 addr == ia->ia_addr.sin_addr.s_addr)
559 * Check the case when bridge shares its MAC address with
560 * some of its children, so packets are claimed by bridge
561 * itself (bridge_input() does it first), but they are really
562 * meant to be destined to the bridge member.
565 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
566 if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) {
567 ifa_ref(&ia->ia_ifa);
574 #undef BDG_MEMBER_MATCHES_ARP
578 * No match, use the first inet address on the receive interface
579 * as a dummy address for the rest of the function.
582 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
583 if (ifa->ifa_addr->sa_family == AF_INET) {
592 * If bridging, fall back to using any inet address.
595 if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL) {
599 ifa_ref(&ia->ia_ifa);
603 enaddr = (u_int8_t *)IF_LLADDR(ifp);
604 myaddr = ia->ia_addr.sin_addr;
605 ifa_free(&ia->ia_ifa);
606 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
607 goto drop; /* it's from me, ignore it. */
608 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
610 "arp: link address is broadcast for IP address %s!\n",
615 * Warn if another host is using the same IP address, but only if the
616 * IP address isn't 0.0.0.0, which is used for DHCP only, in which
617 * case we suppress the warning to avoid false positive complaints of
618 * potential misconfiguration.
620 if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
622 "arp: %*D is using my IP address %s on %s!\n",
623 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
624 inet_ntoa(isaddr), ifp->if_xname);
629 if (ifp->if_flags & IFF_STATICARP)
632 bzero(&sin, sizeof(sin));
633 sin.sin_len = sizeof(struct sockaddr_in);
634 sin.sin_family = AF_INET;
635 sin.sin_addr = isaddr;
636 flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0;
637 flags |= LLE_EXCLUSIVE;
639 la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
640 IF_AFDATA_UNLOCK(ifp);
642 /* the following is not an error when doing bridging */
643 if (!bridged && la->lle_tbl->llt_ifp != ifp && !carp_match) {
644 if (log_arp_wrong_iface)
645 log(LOG_ERR, "arp: %s is on %s "
646 "but got reply from %*D on %s\n",
648 la->lle_tbl->llt_ifp->if_xname,
649 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
654 if ((la->la_flags & LLE_VALID) &&
655 bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
656 if (la->la_flags & LLE_STATIC) {
659 "arp: %*D attempts to modify permanent "
660 "entry for %s on %s\n",
661 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
662 inet_ntoa(isaddr), ifp->if_xname);
665 if (log_arp_movements) {
666 log(LOG_INFO, "arp: %s moved from %*D "
670 (u_char *)&la->ll_addr, ":",
671 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
676 if (ifp->if_addrlen != ah->ar_hln) {
679 "arp from %*D: addr len: new %d, i/f %d (ignored)",
680 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
681 ah->ar_hln, ifp->if_addrlen);
684 (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
685 la->la_flags |= LLE_VALID;
687 if (!(la->la_flags & LLE_STATIC)) {
691 la->la_expire = time_second + V_arpt_keep;
692 canceled = callout_reset(&la->la_timer,
693 hz * V_arpt_keep, arptimer, la);
698 la->la_preempt = V_arp_maxtries;
702 memcpy(&sa, L3_ADDR(la), sizeof(sa));
706 (*ifp->if_output)(ifp, hold, &sa, NULL);
709 if (op != ARPOP_REQUEST)
711 ARPSTAT_INC(rxrequests);
713 if (itaddr.s_addr == myaddr.s_addr) {
714 /* Shortcut.. the receiving interface is the target. */
715 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
716 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
718 struct llentry *lle = NULL;
720 sin.sin_addr = itaddr;
722 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
723 IF_AFDATA_UNLOCK(ifp);
725 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
726 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
727 (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
737 sin.sin_addr = itaddr;
738 /* XXX MRT use table 0 for arp reply */
739 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
744 * Don't send proxies for nodes on the same interface
745 * as this one came out of, or we'll get into a fight
746 * over who claims what Ether address.
748 if (!rt->rt_ifp || rt->rt_ifp == ifp) {
754 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
755 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
758 * Also check that the node which sent the ARP packet
759 * is on the the interface we expect it to be on. This
760 * avoids ARP chaos if an interface is connected to the
763 sin.sin_addr = isaddr;
765 /* XXX MRT use table 0 for arp checks */
766 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
769 if (rt->rt_ifp != ifp) {
770 log(LOG_INFO, "arp_proxy: ignoring request"
771 " from %s via %s, expecting %s\n",
772 inet_ntoa(isaddr), ifp->if_xname,
773 rt->rt_ifp->if_xname);
780 printf("arp: proxying for %s\n",
786 if (itaddr.s_addr == myaddr.s_addr &&
787 IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
788 /* RFC 3927 link-local IPv4; always reply by broadcast. */
789 #ifdef DEBUG_LINKLOCAL
790 printf("arp: sending reply for link-local addr %s\n",
793 m->m_flags |= M_BCAST;
794 m->m_flags &= ~M_MCAST;
796 /* default behaviour; never reply by broadcast. */
797 m->m_flags &= ~(M_BCAST|M_MCAST);
799 (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
800 (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
801 ah->ar_op = htons(ARPOP_REPLY);
802 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
803 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
804 m->m_pkthdr.len = m->m_len;
805 sa.sa_family = AF_ARP;
807 (*ifp->if_output)(ifp, m, &sa, NULL);
808 ARPSTAT_INC(txreplies);
817 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
821 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) {
822 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
823 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
825 * interface address is considered static entry
826 * because the output of the arp utility shows
827 * that L2 entry as permanent
830 lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC),
831 (struct sockaddr *)IA_SIN(ifa));
832 IF_AFDATA_UNLOCK(ifp);
834 log(LOG_INFO, "arp_ifinit: cannot create arp "
835 "entry for interface address\n");
839 ifa->ifa_rtrequest = NULL;
843 arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
845 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
846 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
847 &IA_SIN(ifa)->sin_addr, enaddr);
848 ifa->ifa_rtrequest = NULL;
855 netisr_register(&arp_nh);
857 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);