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
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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("$FreeBSD$");
44 #include <sys/param.h>
45 #include <sys/kernel.h>
46 #include <sys/queue.h>
47 #include <sys/sysctl.h>
48 #include <sys/systm.h>
50 #include <sys/malloc.h>
52 #include <sys/socket.h>
53 #include <sys/syslog.h>
56 #include <net/if_dl.h>
57 #include <net/if_types.h>
58 #include <net/netisr.h>
59 #include <net/if_llc.h>
60 #include <net/ethernet.h>
61 #include <net/route.h>
64 #include <netinet/in.h>
65 #include <netinet/in_var.h>
66 #include <net/if_llatbl.h>
67 #include <netinet/if_ether.h>
69 #include <net/if_arc.h>
70 #include <net/iso88025.h>
73 #include <netinet/ip_carp.h>
76 #include <security/mac/mac_framework.h>
78 #define SIN(s) ((struct sockaddr_in *)s)
79 #define SDL(s) ((struct sockaddr_dl *)s)
81 SYSCTL_DECL(_net_link_ether);
82 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
84 VNET_DEFINE(int, useloopback) = 1; /* use loopback interface for
88 static VNET_DEFINE(int, arpt_keep) = (20*60); /* once resolved, good for 20
90 static VNET_DEFINE(int, arpt_down) = 20; /* keep incomplete entries for
92 static VNET_DEFINE(int, arp_maxtries) = 5;
93 static VNET_DEFINE(int, arp_proxyall);
95 #define V_arpt_keep VNET(arpt_keep)
96 #define V_arpt_down VNET(arpt_down)
97 #define V_arp_maxtries VNET(arp_maxtries)
98 #define V_arp_proxyall VNET(arp_proxyall)
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");
104 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
105 &VNET_NAME(arp_maxtries), 0,
106 "ARP resolution attempts before returning error");
107 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
108 &VNET_NAME(useloopback), 0,
109 "Use the loopback interface for local traffic");
110 SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
111 &VNET_NAME(arp_proxyall), 0,
112 "Enable proxy ARP for all suitable requests");
114 static void arp_init(void);
115 void arprequest(struct ifnet *,
116 struct in_addr *, struct in_addr *, u_char *);
117 static void arpintr(struct mbuf *);
118 static void arptimer(void *);
120 static void in_arpinput(struct mbuf *);
123 static const struct netisr_handler arp_nh = {
125 .nh_handler = arpintr,
126 .nh_proto = NETISR_ARP,
127 .nh_policy = NETISR_POLICY_SOURCE,
131 void arp_ifscrub(struct ifnet *ifp, uint32_t addr);
134 * called by in_ifscrub to remove entry from the table when
135 * the interface goes away
138 arp_ifscrub(struct ifnet *ifp, uint32_t addr)
140 struct sockaddr_in addr4;
142 bzero((void *)&addr4, sizeof(addr4));
143 addr4.sin_len = sizeof(addr4);
144 addr4.sin_family = AF_INET;
145 addr4.sin_addr.s_addr = addr;
146 CURVNET_SET(ifp->if_vnet);
148 lla_lookup(LLTABLE(ifp), (LLE_DELETE | LLE_IFADDR),
149 (struct sockaddr *)&addr4);
150 IF_AFDATA_UNLOCK(ifp);
156 * Timeout routine. Age arp_tab entries periodically.
162 struct llentry *lle = (struct llentry *)arg;
165 panic("%s: NULL entry!\n", __func__);
168 ifp = lle->lle_tbl->llt_ifp;
171 if ((!callout_pending(&lle->la_timer) &&
172 callout_active(&lle->la_timer))) {
173 (void) llentry_free(lle);
177 struct sockaddr *l3addr = L3_ADDR(lle);
178 log(LOG_INFO, "arptimer issue: %p, IPv4 address: \"%s\"\n", lle,
179 inet_ntoa(((const struct sockaddr_in *)l3addr)->sin_addr));
182 IF_AFDATA_UNLOCK(ifp);
186 * Broadcast an ARP request. Caller specifies:
187 * - arp header source ip address
188 * - arp header target ip address
189 * - arp header source ethernet address
192 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip,
200 /* XXX don't believe this can happen (or explain why) */
202 * The caller did not supply a source address, try to find
203 * a compatible one among those assigned to this interface.
207 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
208 if (!ifa->ifa_addr ||
209 ifa->ifa_addr->sa_family != AF_INET)
211 sip = &SIN(ifa->ifa_addr)->sin_addr;
212 if (0 == ((sip->s_addr ^ tip->s_addr) &
213 SIN(ifa->ifa_netmask)->sin_addr.s_addr) )
214 break; /* found it. */
217 printf("%s: cannot find matching address\n", __func__);
222 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
224 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
225 2*ifp->if_data.ifi_addrlen;
226 m->m_pkthdr.len = m->m_len;
227 MH_ALIGN(m, m->m_len);
228 ah = mtod(m, struct arphdr *);
229 bzero((caddr_t)ah, m->m_len);
231 mac_netinet_arp_send(ifp, m);
233 ah->ar_pro = htons(ETHERTYPE_IP);
234 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
235 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
236 ah->ar_op = htons(ARPOP_REQUEST);
237 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
238 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
239 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
240 sa.sa_family = AF_ARP;
242 m->m_flags |= M_BCAST;
243 (*ifp->if_output)(ifp, m, &sa, NULL);
247 * Resolve an IP address into an ethernet address.
249 * ifp is the interface we use
250 * rt0 is the route to the final destination (possibly useless)
251 * m is the mbuf. May be NULL if we don't have a packet.
252 * dst is the next hop,
253 * desten is where we want the address.
255 * On success, desten is filled in and the function returns 0;
256 * If the packet must be held pending resolution, we return EWOULDBLOCK
257 * On other errors, we return the corresponding error code.
258 * Note that m_freem() handles NULL.
261 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
262 struct sockaddr *dst, u_char *desten, struct llentry **lle)
264 struct llentry *la = 0;
270 if (m->m_flags & M_BCAST) {
273 ifp->if_broadcastaddr, ifp->if_addrlen);
276 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {
278 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
285 IF_AFDATA_RLOCK(ifp);
286 la = lla_lookup(LLTABLE(ifp), flags, dst);
287 IF_AFDATA_RUNLOCK(ifp);
288 if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0)
289 && ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) {
290 flags |= (LLE_CREATE | LLE_EXCLUSIVE);
291 IF_AFDATA_WLOCK(ifp);
292 la = lla_lookup(LLTABLE(ifp), flags, dst);
293 IF_AFDATA_WUNLOCK(ifp);
296 if (flags & LLE_CREATE)
298 "arpresolve: can't allocate llinfo for %s\n",
299 inet_ntoa(SIN(dst)->sin_addr));
304 if ((la->la_flags & LLE_VALID) &&
305 ((la->la_flags & LLE_STATIC) || la->la_expire > time_second)) {
306 bcopy(&la->ll_addr, desten, ifp->if_addrlen);
308 * If entry has an expiry time and it is approaching,
309 * see if we need to send an ARP request within this
310 * arpt_down interval.
312 if (!(la->la_flags & LLE_STATIC) &&
313 time_second + la->la_preempt > la->la_expire) {
314 arprequest(ifp, NULL,
315 &SIN(dst)->sin_addr, IF_LLADDR(ifp));
325 if (la->la_flags & LLE_STATIC) { /* should not happen! */
326 log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n",
327 inet_ntoa(SIN(dst)->sin_addr));
333 renew = (la->la_asked == 0 || la->la_expire != time_second);
334 if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) {
335 flags |= LLE_EXCLUSIVE;
340 * There is an arptab entry, but no ethernet address
341 * response yet. Replace the held mbuf with this
345 if (la->la_hold != NULL)
346 m_freem(la->la_hold);
348 if (renew == 0 && (flags & LLE_EXCLUSIVE)) {
349 flags &= ~LLE_EXCLUSIVE;
355 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It
356 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
357 * if we have already sent arp_maxtries ARP requests. Retransmit the
358 * ARP request, but not faster than one request per second.
360 if (la->la_asked < V_arp_maxtries)
361 error = EWOULDBLOCK; /* First request. */
364 (rt0->rt_flags & RTF_GATEWAY) ? EHOSTUNREACH : EHOSTDOWN;
368 la->la_expire = time_second + V_arpt_down;
369 callout_reset(&la->la_timer, hz * V_arpt_down, arptimer, la);
372 arprequest(ifp, NULL, &SIN(dst)->sin_addr,
377 if (flags & LLE_EXCLUSIVE)
385 * Common length and type checks are done here,
386 * then the protocol-specific routine is called.
389 arpintr(struct mbuf *m)
393 if (m->m_len < sizeof(struct arphdr) &&
394 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
395 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
398 ar = mtod(m, struct arphdr *);
400 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
401 ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
402 ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
403 ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
404 log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
405 (unsigned char *)&ar->ar_hrd, "");
410 if (m->m_len < arphdr_len(ar)) {
411 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
412 log(LOG_ERR, "arp: runt packet\n");
416 ar = mtod(m, struct arphdr *);
419 switch (ntohs(ar->ar_pro)) {
431 * ARP for Internet protocols on 10 Mb/s Ethernet.
432 * Algorithm is that given in RFC 826.
433 * In addition, a sanity check is performed on the sender
434 * protocol address, to catch impersonators.
435 * We no longer handle negotiations for use of trailer protocol:
436 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
437 * along with IP replies if we wanted trailers sent to us,
438 * and also sent them in response to IP replies.
439 * This allowed either end to announce the desire to receive
441 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
442 * but formerly didn't normally send requests.
444 static int log_arp_wrong_iface = 1;
445 static int log_arp_movements = 1;
446 static int log_arp_permanent_modify = 1;
448 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
449 &log_arp_wrong_iface, 0,
450 "log arp packets arriving on the wrong interface");
451 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
452 &log_arp_movements, 0,
453 "log arp replies from MACs different than the one in the cache");
454 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
455 &log_arp_permanent_modify, 0,
456 "log arp replies from MACs different than the one in the permanent arp entry");
460 in_arpinput(struct mbuf *m)
463 struct ifnet *ifp = m->m_pkthdr.rcvif;
464 struct llentry *la = NULL;
467 struct in_ifaddr *ia;
470 struct in_addr isaddr, itaddr, myaddr;
471 u_int8_t *enaddr = NULL;
474 int bridged = 0, is_bridge = 0;
478 struct sockaddr_in sin;
479 sin.sin_len = sizeof(struct sockaddr_in);
480 sin.sin_family = AF_INET;
481 sin.sin_addr.s_addr = 0;
485 if (ifp->if_type == IFT_BRIDGE)
488 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
489 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
490 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
494 ah = mtod(m, struct arphdr *);
495 op = ntohs(ah->ar_op);
496 (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
497 (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
500 * For a bridge, we want to check the address irrespective
501 * of the receive interface. (This will change slightly
502 * when we have clusters of interfaces).
503 * If the interface does not match, but the recieving interface
504 * is part of carp, we call carp_iamatch to see if this is a
505 * request for the virtual host ip.
506 * XXX: This is really ugly!
509 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
510 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
511 ia->ia_ifp == ifp) &&
512 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
513 ifa_ref(&ia->ia_ifa);
518 if (ifp->if_carp != NULL &&
519 carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) &&
520 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
522 ifa_ref(&ia->ia_ifa);
528 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
529 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
530 ia->ia_ifp == ifp) &&
531 isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
532 ifa_ref(&ia->ia_ifa);
537 #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \
538 (ia->ia_ifp->if_bridge == ifp->if_softc && \
539 !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \
540 addr == ia->ia_addr.sin_addr.s_addr)
542 * Check the case when bridge shares its MAC address with
543 * some of its children, so packets are claimed by bridge
544 * itself (bridge_input() does it first), but they are really
545 * meant to be destined to the bridge member.
548 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
549 if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) {
550 ifa_ref(&ia->ia_ifa);
557 #undef BDG_MEMBER_MATCHES_ARP
561 * No match, use the first inet address on the receive interface
562 * as a dummy address for the rest of the function.
565 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
566 if (ifa->ifa_addr->sa_family == AF_INET) {
575 * If bridging, fall back to using any inet address.
578 if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL) {
582 ifa_ref(&ia->ia_ifa);
586 enaddr = (u_int8_t *)IF_LLADDR(ifp);
587 myaddr = ia->ia_addr.sin_addr;
588 ifa_free(&ia->ia_ifa);
589 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
590 goto drop; /* it's from me, ignore it. */
591 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
593 "arp: link address is broadcast for IP address %s!\n",
598 * Warn if another host is using the same IP address, but only if the
599 * IP address isn't 0.0.0.0, which is used for DHCP only, in which
600 * case we suppress the warning to avoid false positive complaints of
601 * potential misconfiguration.
603 if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
605 "arp: %*D is using my IP address %s on %s!\n",
606 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
607 inet_ntoa(isaddr), ifp->if_xname);
611 if (ifp->if_flags & IFF_STATICARP)
614 bzero(&sin, sizeof(sin));
615 sin.sin_len = sizeof(struct sockaddr_in);
616 sin.sin_family = AF_INET;
617 sin.sin_addr = isaddr;
618 flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0;
619 flags |= LLE_EXCLUSIVE;
621 la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
622 IF_AFDATA_UNLOCK(ifp);
624 /* the following is not an error when doing bridging */
625 if (!bridged && la->lle_tbl->llt_ifp != ifp
627 && (ifp->if_type != IFT_CARP || !carp_match)
630 if (log_arp_wrong_iface)
631 log(LOG_ERR, "arp: %s is on %s "
632 "but got reply from %*D on %s\n",
634 la->lle_tbl->llt_ifp->if_xname,
635 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
640 if ((la->la_flags & LLE_VALID) &&
641 bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
642 if (la->la_flags & LLE_STATIC) {
645 "arp: %*D attempts to modify permanent "
646 "entry for %s on %s\n",
647 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
648 inet_ntoa(isaddr), ifp->if_xname);
651 if (log_arp_movements) {
652 log(LOG_INFO, "arp: %s moved from %*D "
656 (u_char *)&la->ll_addr, ":",
657 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
662 if (ifp->if_addrlen != ah->ar_hln) {
665 "arp from %*D: addr len: new %d, i/f %d (ignored)",
666 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
667 ah->ar_hln, ifp->if_addrlen);
670 (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
671 la->la_flags |= LLE_VALID;
673 if (!(la->la_flags & LLE_STATIC)) {
674 la->la_expire = time_second + V_arpt_keep;
675 callout_reset(&la->la_timer, hz * V_arpt_keep,
679 la->la_preempt = V_arp_maxtries;
683 memcpy(&sa, L3_ADDR(la), sizeof(sa));
687 (*ifp->if_output)(ifp, hold, &sa, NULL);
690 if (op != ARPOP_REQUEST)
693 if (itaddr.s_addr == myaddr.s_addr) {
694 /* Shortcut.. the receiving interface is the target. */
695 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
696 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
698 struct llentry *lle = NULL;
700 sin.sin_addr = itaddr;
702 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
703 IF_AFDATA_UNLOCK(ifp);
705 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
706 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
707 (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
717 sin.sin_addr = itaddr;
718 /* XXX MRT use table 0 for arp reply */
719 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
724 * Don't send proxies for nodes on the same interface
725 * as this one came out of, or we'll get into a fight
726 * over who claims what Ether address.
728 if (!rt->rt_ifp || rt->rt_ifp == ifp) {
734 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
735 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
738 * Also check that the node which sent the ARP packet
739 * is on the the interface we expect it to be on. This
740 * avoids ARP chaos if an interface is connected to the
743 sin.sin_addr = isaddr;
745 /* XXX MRT use table 0 for arp checks */
746 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
749 if (rt->rt_ifp != ifp) {
750 log(LOG_INFO, "arp_proxy: ignoring request"
751 " from %s via %s, expecting %s\n",
752 inet_ntoa(isaddr), ifp->if_xname,
753 rt->rt_ifp->if_xname);
760 printf("arp: proxying for %s\n",
766 if (itaddr.s_addr == myaddr.s_addr &&
767 IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
768 /* RFC 3927 link-local IPv4; always reply by broadcast. */
769 #ifdef DEBUG_LINKLOCAL
770 printf("arp: sending reply for link-local addr %s\n",
773 m->m_flags |= M_BCAST;
774 m->m_flags &= ~M_MCAST;
776 /* default behaviour; never reply by broadcast. */
777 m->m_flags &= ~(M_BCAST|M_MCAST);
779 (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
780 (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
781 ah->ar_op = htons(ARPOP_REPLY);
782 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
783 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
784 m->m_pkthdr.len = m->m_len;
785 sa.sa_family = AF_ARP;
787 (*ifp->if_output)(ifp, m, &sa, NULL);
796 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
800 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) {
801 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
802 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
804 * interface address is considered static entry
805 * because the output of the arp utility shows
806 * that L2 entry as permanent
809 lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC),
810 (struct sockaddr *)IA_SIN(ifa));
811 IF_AFDATA_UNLOCK(ifp);
813 log(LOG_INFO, "arp_ifinit: cannot create arp "
814 "entry for interface address\n");
818 ifa->ifa_rtrequest = NULL;
822 arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
824 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
825 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
826 &IA_SIN(ifa)->sin_addr, enaddr);
827 ifa->ifa_rtrequest = NULL;
834 netisr_register(&arp_nh);
836 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);