2 * Copyright (c) 1982, 1986, 1988, 1993
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6 * modification, are permitted provided that the following conditions
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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 (lle->la_flags & LLE_STATIC)
174 if (!callout_pending(&lle->la_timer) &&
175 callout_active(&lle->la_timer)) {
176 (void) llentry_free(lle);
180 struct sockaddr *l3addr = L3_ADDR(lle);
182 "arptimer issue: %p, IPv4 address: \"%s\"\n", lle,
184 ((const struct sockaddr_in *)l3addr)->sin_addr));
188 IF_AFDATA_UNLOCK(ifp);
192 * Broadcast an ARP request. Caller specifies:
193 * - arp header source ip address
194 * - arp header target ip address
195 * - arp header source ethernet address
198 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip,
206 /* XXX don't believe this can happen (or explain why) */
208 * The caller did not supply a source address, try to find
209 * a compatible one among those assigned to this interface.
213 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
214 if (!ifa->ifa_addr ||
215 ifa->ifa_addr->sa_family != AF_INET)
217 sip = &SIN(ifa->ifa_addr)->sin_addr;
218 if (0 == ((sip->s_addr ^ tip->s_addr) &
219 SIN(ifa->ifa_netmask)->sin_addr.s_addr) )
220 break; /* found it. */
223 printf("%s: cannot find matching address\n", __func__);
228 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
230 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
231 2*ifp->if_data.ifi_addrlen;
232 m->m_pkthdr.len = m->m_len;
233 MH_ALIGN(m, m->m_len);
234 ah = mtod(m, struct arphdr *);
235 bzero((caddr_t)ah, m->m_len);
237 mac_netinet_arp_send(ifp, m);
239 ah->ar_pro = htons(ETHERTYPE_IP);
240 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
241 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
242 ah->ar_op = htons(ARPOP_REQUEST);
243 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
244 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
245 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
246 sa.sa_family = AF_ARP;
248 m->m_flags |= M_BCAST;
249 (*ifp->if_output)(ifp, m, &sa, NULL);
253 * Resolve an IP address into an ethernet address.
255 * ifp is the interface we use
256 * rt0 is the route to the final destination (possibly useless)
257 * m is the mbuf. May be NULL if we don't have a packet.
258 * dst is the next hop,
259 * desten is where we want the address.
261 * On success, desten is filled in and the function returns 0;
262 * If the packet must be held pending resolution, we return EWOULDBLOCK
263 * On other errors, we return the corresponding error code.
264 * Note that m_freem() handles NULL.
267 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
268 struct sockaddr *dst, u_char *desten, struct llentry **lle)
270 struct llentry *la = 0;
276 if (m->m_flags & M_BCAST) {
279 ifp->if_broadcastaddr, ifp->if_addrlen);
282 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {
284 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
291 IF_AFDATA_RLOCK(ifp);
292 la = lla_lookup(LLTABLE(ifp), flags, dst);
293 IF_AFDATA_RUNLOCK(ifp);
294 if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0)
295 && ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) {
296 flags |= (LLE_CREATE | LLE_EXCLUSIVE);
297 IF_AFDATA_WLOCK(ifp);
298 la = lla_lookup(LLTABLE(ifp), flags, dst);
299 IF_AFDATA_WUNLOCK(ifp);
302 if (flags & LLE_CREATE)
304 "arpresolve: can't allocate llinfo for %s\n",
305 inet_ntoa(SIN(dst)->sin_addr));
310 if ((la->la_flags & LLE_VALID) &&
311 ((la->la_flags & LLE_STATIC) || la->la_expire > time_second)) {
312 bcopy(&la->ll_addr, desten, ifp->if_addrlen);
314 * If entry has an expiry time and it is approaching,
315 * see if we need to send an ARP request within this
316 * arpt_down interval.
318 if (!(la->la_flags & LLE_STATIC) &&
319 time_second + la->la_preempt > la->la_expire) {
320 arprequest(ifp, NULL,
321 &SIN(dst)->sin_addr, IF_LLADDR(ifp));
331 if (la->la_flags & LLE_STATIC) { /* should not happen! */
332 log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n",
333 inet_ntoa(SIN(dst)->sin_addr));
339 renew = (la->la_asked == 0 || la->la_expire != time_second);
340 if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) {
341 flags |= LLE_EXCLUSIVE;
346 * There is an arptab entry, but no ethernet address
347 * response yet. Replace the held mbuf with this
351 if (la->la_hold != NULL)
352 m_freem(la->la_hold);
354 if (renew == 0 && (flags & LLE_EXCLUSIVE)) {
355 flags &= ~LLE_EXCLUSIVE;
361 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It
362 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
363 * if we have already sent arp_maxtries ARP requests. Retransmit the
364 * ARP request, but not faster than one request per second.
366 if (la->la_asked < V_arp_maxtries)
367 error = EWOULDBLOCK; /* First request. */
369 error = rt0 != NULL && (rt0->rt_flags & RTF_GATEWAY) ?
370 EHOSTUNREACH : EHOSTDOWN;
374 la->la_expire = time_second + V_arpt_down;
375 callout_reset(&la->la_timer, hz * V_arpt_down, arptimer, la);
378 arprequest(ifp, NULL, &SIN(dst)->sin_addr,
383 if (flags & LLE_EXCLUSIVE)
391 * Common length and type checks are done here,
392 * then the protocol-specific routine is called.
395 arpintr(struct mbuf *m)
399 if (m->m_len < sizeof(struct arphdr) &&
400 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
401 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
404 ar = mtod(m, struct arphdr *);
406 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
407 ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
408 ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
409 ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
410 log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
411 (unsigned char *)&ar->ar_hrd, "");
416 if (m->m_len < arphdr_len(ar)) {
417 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
418 log(LOG_ERR, "arp: runt packet\n");
422 ar = mtod(m, struct arphdr *);
425 switch (ntohs(ar->ar_pro)) {
437 * ARP for Internet protocols on 10 Mb/s Ethernet.
438 * Algorithm is that given in RFC 826.
439 * In addition, a sanity check is performed on the sender
440 * protocol address, to catch impersonators.
441 * We no longer handle negotiations for use of trailer protocol:
442 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
443 * along with IP replies if we wanted trailers sent to us,
444 * and also sent them in response to IP replies.
445 * This allowed either end to announce the desire to receive
447 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
448 * but formerly didn't normally send requests.
450 static int log_arp_wrong_iface = 1;
451 static int log_arp_movements = 1;
452 static int log_arp_permanent_modify = 1;
454 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
455 &log_arp_wrong_iface, 0,
456 "log arp packets arriving on the wrong interface");
457 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
458 &log_arp_movements, 0,
459 "log arp replies from MACs different than the one in the cache");
460 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
461 &log_arp_permanent_modify, 0,
462 "log arp replies from MACs different than the one in the permanent arp entry");
466 in_arpinput(struct mbuf *m)
469 struct ifnet *ifp = m->m_pkthdr.rcvif;
470 struct llentry *la = NULL;
473 struct in_ifaddr *ia;
476 struct in_addr isaddr, itaddr, myaddr;
477 u_int8_t *enaddr = NULL;
480 int bridged = 0, is_bridge = 0;
484 struct sockaddr_in sin;
485 sin.sin_len = sizeof(struct sockaddr_in);
486 sin.sin_family = AF_INET;
487 sin.sin_addr.s_addr = 0;
491 if (ifp->if_type == IFT_BRIDGE)
494 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
495 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
496 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
500 ah = mtod(m, struct arphdr *);
501 op = ntohs(ah->ar_op);
502 (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
503 (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
506 * For a bridge, we want to check the address irrespective
507 * of the receive interface. (This will change slightly
508 * when we have clusters of interfaces).
509 * If the interface does not match, but the recieving interface
510 * is part of carp, we call carp_iamatch to see if this is a
511 * request for the virtual host ip.
512 * XXX: This is really ugly!
515 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
516 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
517 ia->ia_ifp == ifp) &&
518 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
519 ifa_ref(&ia->ia_ifa);
524 if (ifp->if_carp != NULL &&
525 carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) &&
526 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
528 ifa_ref(&ia->ia_ifa);
534 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
535 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
536 ia->ia_ifp == ifp) &&
537 isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
538 ifa_ref(&ia->ia_ifa);
543 #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \
544 (ia->ia_ifp->if_bridge == ifp->if_softc && \
545 !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \
546 addr == ia->ia_addr.sin_addr.s_addr)
548 * Check the case when bridge shares its MAC address with
549 * some of its children, so packets are claimed by bridge
550 * itself (bridge_input() does it first), but they are really
551 * meant to be destined to the bridge member.
554 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
555 if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) {
556 ifa_ref(&ia->ia_ifa);
563 #undef BDG_MEMBER_MATCHES_ARP
567 * No match, use the first inet address on the receive interface
568 * as a dummy address for the rest of the function.
571 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
572 if (ifa->ifa_addr->sa_family == AF_INET) {
581 * If bridging, fall back to using any inet address.
584 if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL) {
588 ifa_ref(&ia->ia_ifa);
592 enaddr = (u_int8_t *)IF_LLADDR(ifp);
593 myaddr = ia->ia_addr.sin_addr;
594 ifa_free(&ia->ia_ifa);
595 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
596 goto drop; /* it's from me, ignore it. */
597 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
599 "arp: link address is broadcast for IP address %s!\n",
604 * Warn if another host is using the same IP address, but only if the
605 * IP address isn't 0.0.0.0, which is used for DHCP only, in which
606 * case we suppress the warning to avoid false positive complaints of
607 * potential misconfiguration.
609 if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
611 "arp: %*D is using my IP address %s on %s!\n",
612 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
613 inet_ntoa(isaddr), ifp->if_xname);
617 if (ifp->if_flags & IFF_STATICARP)
620 bzero(&sin, sizeof(sin));
621 sin.sin_len = sizeof(struct sockaddr_in);
622 sin.sin_family = AF_INET;
623 sin.sin_addr = isaddr;
624 flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0;
625 flags |= LLE_EXCLUSIVE;
627 la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
628 IF_AFDATA_UNLOCK(ifp);
630 /* the following is not an error when doing bridging */
631 if (!bridged && la->lle_tbl->llt_ifp != ifp
633 && (ifp->if_type != IFT_CARP || !carp_match)
636 if (log_arp_wrong_iface)
637 log(LOG_ERR, "arp: %s is on %s "
638 "but got reply from %*D on %s\n",
640 la->lle_tbl->llt_ifp->if_xname,
641 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
646 if ((la->la_flags & LLE_VALID) &&
647 bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
648 if (la->la_flags & LLE_STATIC) {
651 "arp: %*D attempts to modify permanent "
652 "entry for %s on %s\n",
653 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
654 inet_ntoa(isaddr), ifp->if_xname);
657 if (log_arp_movements) {
658 log(LOG_INFO, "arp: %s moved from %*D "
662 (u_char *)&la->ll_addr, ":",
663 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
668 if (ifp->if_addrlen != ah->ar_hln) {
671 "arp from %*D: addr len: new %d, i/f %d (ignored)",
672 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
673 ah->ar_hln, ifp->if_addrlen);
676 (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
677 la->la_flags |= LLE_VALID;
679 if (!(la->la_flags & LLE_STATIC)) {
680 la->la_expire = time_second + V_arpt_keep;
681 callout_reset(&la->la_timer, hz * V_arpt_keep,
685 la->la_preempt = V_arp_maxtries;
689 memcpy(&sa, L3_ADDR(la), sizeof(sa));
693 (*ifp->if_output)(ifp, hold, &sa, NULL);
696 if (op != ARPOP_REQUEST)
699 if (itaddr.s_addr == myaddr.s_addr) {
700 /* Shortcut.. the receiving interface is the target. */
701 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
702 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
704 struct llentry *lle = NULL;
706 sin.sin_addr = itaddr;
708 lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin);
709 IF_AFDATA_UNLOCK(ifp);
711 if ((lle != NULL) && (lle->la_flags & LLE_PUB)) {
712 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
713 (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
723 sin.sin_addr = itaddr;
724 /* XXX MRT use table 0 for arp reply */
725 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
730 * Don't send proxies for nodes on the same interface
731 * as this one came out of, or we'll get into a fight
732 * over who claims what Ether address.
734 if (!rt->rt_ifp || rt->rt_ifp == ifp) {
740 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
741 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
744 * Also check that the node which sent the ARP packet
745 * is on the the interface we expect it to be on. This
746 * avoids ARP chaos if an interface is connected to the
749 sin.sin_addr = isaddr;
751 /* XXX MRT use table 0 for arp checks */
752 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
755 if (rt->rt_ifp != ifp) {
756 log(LOG_INFO, "arp_proxy: ignoring request"
757 " from %s via %s, expecting %s\n",
758 inet_ntoa(isaddr), ifp->if_xname,
759 rt->rt_ifp->if_xname);
766 printf("arp: proxying for %s\n",
772 if (itaddr.s_addr == myaddr.s_addr &&
773 IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
774 /* RFC 3927 link-local IPv4; always reply by broadcast. */
775 #ifdef DEBUG_LINKLOCAL
776 printf("arp: sending reply for link-local addr %s\n",
779 m->m_flags |= M_BCAST;
780 m->m_flags &= ~M_MCAST;
782 /* default behaviour; never reply by broadcast. */
783 m->m_flags &= ~(M_BCAST|M_MCAST);
785 (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
786 (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
787 ah->ar_op = htons(ARPOP_REPLY);
788 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
789 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
790 m->m_pkthdr.len = m->m_len;
791 sa.sa_family = AF_ARP;
793 (*ifp->if_output)(ifp, m, &sa, NULL);
802 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
806 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) {
807 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
808 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
810 * interface address is considered static entry
811 * because the output of the arp utility shows
812 * that L2 entry as permanent
815 lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC),
816 (struct sockaddr *)IA_SIN(ifa));
817 IF_AFDATA_UNLOCK(ifp);
819 log(LOG_INFO, "arp_ifinit: cannot create arp "
820 "entry for interface address\n");
824 ifa->ifa_rtrequest = NULL;
828 arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
830 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
831 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
832 &IA_SIN(ifa)->sin_addr, enaddr);
833 ifa->ifa_rtrequest = NULL;
840 netisr_register(&arp_nh);
842 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);