2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
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.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
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)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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("$FreeBSD$");
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>
54 #include <sys/vimage.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 #include <net/netisr.h>
60 #include <net/if_llc.h>
61 #include <net/ethernet.h>
62 #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>
68 #include <netinet/vinet.h>
70 #include <net/if_arc.h>
71 #include <net/iso88025.h>
74 #include <netinet/ip_carp.h>
77 #include <security/mac/mac_framework.h>
79 #define SIN(s) ((struct sockaddr_in *)s)
80 #define SDL(s) ((struct sockaddr_dl *)s)
82 SYSCTL_DECL(_net_link_ether);
83 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
87 static int arpt_keep; /* once resolved, good for 20 more minutes */
88 static int arp_maxtries;
89 int useloopback; /* use loopback interface for local traffic */
90 static int arp_proxyall;
93 SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, max_age,
94 CTLFLAG_RW, arpt_keep, 0, "ARP entry lifetime in seconds");
96 SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, maxtries,
97 CTLFLAG_RW, arp_maxtries, 0,
98 "ARP resolution attempts before returning error");
99 SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, useloopback,
100 CTLFLAG_RW, useloopback, 0,
101 "Use the loopback interface for local traffic");
102 SYSCTL_V_INT(V_NET, vnet_inet, _net_link_ether_inet, OID_AUTO, proxyall,
103 CTLFLAG_RW, arp_proxyall, 0,
104 "Enable proxy ARP for all suitable requests");
106 static void arp_init(void);
107 static int arp_iattach(const void *);
108 void arprequest(struct ifnet *,
109 struct in_addr *, struct in_addr *, u_char *);
110 static void arpintr(struct mbuf *);
111 static void arptimer(void *);
113 static void in_arpinput(struct mbuf *);
116 static const struct netisr_handler arp_nh = {
118 .nh_handler = arpintr,
119 .nh_proto = NETISR_ARP,
120 .nh_policy = NETISR_POLICY_SOURCE,
123 #ifndef VIMAGE_GLOBALS
124 static const vnet_modinfo_t vnet_arp_modinfo = {
125 .vmi_id = VNET_MOD_ARP,
127 .vmi_dependson = VNET_MOD_INET,
128 .vmi_iattach = arp_iattach
130 #endif /* !VIMAGE_GLOBALS */
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;
148 CURVNET_SET(ifp->if_vnet);
150 lla_lookup(LLTABLE(ifp), (LLE_DELETE | LLE_IFADDR),
151 (struct sockaddr *)&addr4);
152 IF_AFDATA_UNLOCK(ifp);
158 * Timeout routine. Age arp_tab entries periodically.
164 struct llentry *lle = (struct llentry *)arg;
167 panic("%s: NULL entry!\n", __func__);
170 ifp = lle->lle_tbl->llt_ifp;
173 if (((lle->la_flags & LLE_DELETED)
174 || (time_second >= lle->la_expire))
175 && (!callout_pending(&lle->la_timer) &&
176 callout_active(&lle->la_timer)))
177 (void) llentry_free(lle);
180 * Still valid, just drop our reference
182 LLE_FREE_LOCKED(lle);
184 IF_AFDATA_UNLOCK(ifp);
188 * Broadcast an ARP request. Caller specifies:
189 * - arp header source ip address
190 * - arp header target ip address
191 * - arp header source ethernet address
194 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip,
202 /* XXX don't believe this can happen (or explain why) */
204 * The caller did not supply a source address, try to find
205 * a compatible one among those assigned to this interface.
209 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
210 if (!ifa->ifa_addr ||
211 ifa->ifa_addr->sa_family != AF_INET)
213 sip = &SIN(ifa->ifa_addr)->sin_addr;
214 if (0 == ((sip->s_addr ^ tip->s_addr) &
215 SIN(ifa->ifa_netmask)->sin_addr.s_addr) )
216 break; /* found it. */
219 printf("%s: cannot find matching address\n", __func__);
224 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
226 m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) +
227 2*ifp->if_data.ifi_addrlen;
228 m->m_pkthdr.len = m->m_len;
229 MH_ALIGN(m, m->m_len);
230 ah = mtod(m, struct arphdr *);
231 bzero((caddr_t)ah, m->m_len);
233 mac_netinet_arp_send(ifp, m);
235 ah->ar_pro = htons(ETHERTYPE_IP);
236 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
237 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
238 ah->ar_op = htons(ARPOP_REQUEST);
239 bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln);
240 bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln);
241 bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln);
242 sa.sa_family = AF_ARP;
244 m->m_flags |= M_BCAST;
245 (*ifp->if_output)(ifp, m, &sa, NULL);
249 * Resolve an IP address into an ethernet address.
251 * ifp is the interface we use
252 * rt0 is the route to the final destination (possibly useless)
253 * m is the mbuf. May be NULL if we don't have a packet.
254 * dst is the next hop,
255 * desten is where we want the address.
257 * On success, desten is filled in and the function returns 0;
258 * If the packet must be held pending resolution, we return EWOULDBLOCK
259 * On other errors, we return the corresponding error code.
260 * Note that m_freem() handles NULL.
263 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
264 struct sockaddr *dst, u_char *desten, struct llentry **lle)
266 INIT_VNET_INET(ifp->if_vnet);
267 struct llentry *la = 0;
273 if (m->m_flags & M_BCAST) {
276 ifp->if_broadcastaddr, ifp->if_addrlen);
279 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {
281 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
288 IF_AFDATA_RLOCK(ifp);
289 la = lla_lookup(LLTABLE(ifp), flags, dst);
290 IF_AFDATA_RUNLOCK(ifp);
291 if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0)
292 && ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) {
293 flags |= (LLE_CREATE | LLE_EXCLUSIVE);
294 IF_AFDATA_WLOCK(ifp);
295 la = lla_lookup(LLTABLE(ifp), flags, dst);
296 IF_AFDATA_WUNLOCK(ifp);
299 if (flags & LLE_CREATE)
301 "arpresolve: can't allocate llinfo for %s\n",
302 inet_ntoa(SIN(dst)->sin_addr));
307 if ((la->la_flags & LLE_VALID) &&
308 ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) {
309 bcopy(&la->ll_addr, desten, ifp->if_addrlen);
311 * If entry has an expiry time and it is approaching,
312 * see if we need to send an ARP request within this
313 * arpt_down interval.
315 if (!(la->la_flags & LLE_STATIC) &&
316 time_uptime + la->la_preempt > la->la_expire) {
317 arprequest(ifp, NULL,
318 &SIN(dst)->sin_addr, IF_LLADDR(ifp));
328 if (la->la_flags & LLE_STATIC) { /* should not happen! */
329 log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n",
330 inet_ntoa(SIN(dst)->sin_addr));
336 renew = (la->la_asked == 0 || la->la_expire != time_uptime);
337 if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) {
338 flags |= LLE_EXCLUSIVE;
343 * There is an arptab entry, but no ethernet address
344 * response yet. Replace the held mbuf with this
348 if (la->la_hold != NULL)
349 m_freem(la->la_hold);
351 if (renew == 0 && (flags & LLE_EXCLUSIVE)) {
352 flags &= ~LLE_EXCLUSIVE;
358 * Return EWOULDBLOCK if we have tried less than arp_maxtries. It
359 * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH
360 * if we have already sent arp_maxtries ARP requests. Retransmit the
361 * ARP request, but not faster than one request per second.
363 if (la->la_asked < V_arp_maxtries)
364 error = EWOULDBLOCK; /* First request. */
367 (rt0->rt_flags & RTF_GATEWAY) ? EHOSTDOWN : EHOSTUNREACH;
371 la->la_expire = time_uptime;
372 callout_reset(&la->la_timer, hz, arptimer, la);
375 arprequest(ifp, NULL, &SIN(dst)->sin_addr,
380 if (flags & LLE_EXCLUSIVE)
388 * Common length and type checks are done here,
389 * then the protocol-specific routine is called.
392 arpintr(struct mbuf *m)
396 if (m->m_len < sizeof(struct arphdr) &&
397 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
398 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
401 ar = mtod(m, struct arphdr *);
403 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER &&
404 ntohs(ar->ar_hrd) != ARPHRD_IEEE802 &&
405 ntohs(ar->ar_hrd) != ARPHRD_ARCNET &&
406 ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) {
407 log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
408 (unsigned char *)&ar->ar_hrd, "");
413 if (m->m_len < arphdr_len(ar)) {
414 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
415 log(LOG_ERR, "arp: runt packet\n");
419 ar = mtod(m, struct arphdr *);
422 switch (ntohs(ar->ar_pro)) {
434 * ARP for Internet protocols on 10 Mb/s Ethernet.
435 * Algorithm is that given in RFC 826.
436 * In addition, a sanity check is performed on the sender
437 * protocol address, to catch impersonators.
438 * We no longer handle negotiations for use of trailer protocol:
439 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
440 * along with IP replies if we wanted trailers sent to us,
441 * and also sent them in response to IP replies.
442 * This allowed either end to announce the desire to receive
444 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
445 * but formerly didn't normally send requests.
447 static int log_arp_wrong_iface = 1;
448 static int log_arp_movements = 1;
449 static int log_arp_permanent_modify = 1;
451 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
452 &log_arp_wrong_iface, 0,
453 "log arp packets arriving on the wrong interface");
454 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
455 &log_arp_movements, 0,
456 "log arp replies from MACs different than the one in the cache");
457 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
458 &log_arp_permanent_modify, 0,
459 "log arp replies from MACs different than the one in the permanent arp entry");
463 in_arpinput(struct mbuf *m)
466 struct ifnet *ifp = m->m_pkthdr.rcvif;
467 struct llentry *la = NULL;
470 struct in_ifaddr *ia;
472 struct in_addr isaddr, itaddr, myaddr;
473 u_int8_t *enaddr = NULL;
477 int bridged = 0, is_bridge = 0;
481 struct sockaddr_in sin;
482 sin.sin_len = sizeof(struct sockaddr_in);
483 sin.sin_family = AF_INET;
484 sin.sin_addr.s_addr = 0;
485 INIT_VNET_INET(ifp->if_vnet);
489 if (ifp->if_type == IFT_BRIDGE)
492 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
493 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
494 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
498 ah = mtod(m, struct arphdr *);
499 op = ntohs(ah->ar_op);
500 (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
501 (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
504 * For a bridge, we want to check the address irrespective
505 * of the receive interface. (This will change slightly
506 * when we have clusters of interfaces).
507 * If the interface does not match, but the recieving interface
508 * is part of carp, we call carp_iamatch to see if this is a
509 * request for the virtual host ip.
510 * XXX: This is really ugly!
512 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
513 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
514 ia->ia_ifp == ifp) &&
515 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
516 ifa_ref(&ia->ia_ifa);
520 if (ifp->if_carp != NULL &&
521 carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) &&
522 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
524 ifa_ref(&ia->ia_ifa);
529 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
530 if (((bridged && ia->ia_ifp->if_bridge != NULL) ||
531 ia->ia_ifp == ifp) &&
532 isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) {
533 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);
556 #undef BDG_MEMBER_MATCHES_ARP
559 * No match, use the first inet address on the receive interface
560 * as a dummy address for the rest of the function.
563 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
564 if (ifa->ifa_addr->sa_family == AF_INET) {
573 * If bridging, fall back to using any inet address.
575 if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL)
577 ifa_ref(&ia->ia_ifa);
580 enaddr = (u_int8_t *)IF_LLADDR(ifp);
581 myaddr = ia->ia_addr.sin_addr;
582 ifa_free(&ia->ia_ifa);
583 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen))
584 goto drop; /* it's from me, ignore it. */
585 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
587 "arp: link address is broadcast for IP address %s!\n",
592 * Warn if another host is using the same IP address, but only if the
593 * IP address isn't 0.0.0.0, which is used for DHCP only, in which
594 * case we suppress the warning to avoid false positive complaints of
595 * potential misconfiguration.
597 if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
599 "arp: %*D is using my IP address %s on %s!\n",
600 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
601 inet_ntoa(isaddr), ifp->if_xname);
605 if (ifp->if_flags & IFF_STATICARP)
608 bzero(&sin, sizeof(sin));
609 sin.sin_len = sizeof(struct sockaddr_in);
610 sin.sin_family = AF_INET;
611 sin.sin_addr = isaddr;
612 flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0;
613 flags |= LLE_EXCLUSIVE;
615 la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin);
616 IF_AFDATA_UNLOCK(ifp);
618 /* the following is not an error when doing bridging */
619 if (!bridged && la->lle_tbl->llt_ifp != ifp
621 && (ifp->if_type != IFT_CARP || !carp_match)
624 if (log_arp_wrong_iface)
625 log(LOG_ERR, "arp: %s is on %s "
626 "but got reply from %*D on %s\n",
628 la->lle_tbl->llt_ifp->if_xname,
629 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
633 if ((la->la_flags & LLE_VALID) &&
634 bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) {
635 if (la->la_flags & LLE_STATIC) {
637 "arp: %*D attempts to modify permanent "
638 "entry for %s on %s\n",
639 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
640 inet_ntoa(isaddr), ifp->if_xname);
643 if (log_arp_movements) {
644 log(LOG_INFO, "arp: %s moved from %*D "
648 (u_char *)&la->ll_addr, ":",
649 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
654 if (ifp->if_addrlen != ah->ar_hln) {
656 "arp from %*D: addr len: new %d, i/f %d (ignored)",
657 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
658 ah->ar_hln, ifp->if_addrlen);
661 (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen);
662 la->la_flags |= LLE_VALID;
664 if (!(la->la_flags & LLE_STATIC)) {
665 la->la_expire = time_uptime + V_arpt_keep;
666 callout_reset(&la->la_timer, hz * V_arpt_keep,
670 la->la_preempt = V_arp_maxtries;
671 if (la->la_hold != NULL) {
674 memcpy(&sa, L3_ADDR(la), sizeof(sa));
677 (*ifp->if_output)(ifp, m0, &sa, NULL);
682 if (op != ARPOP_REQUEST)
685 if (itaddr.s_addr == myaddr.s_addr) {
686 /* Shortcut.. the receiving interface is the target. */
687 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
688 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
690 struct llentry *lle = NULL;
695 sin.sin_addr = itaddr;
696 /* XXX MRT use table 0 for arp reply */
697 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
702 * Don't send proxies for nodes on the same interface
703 * as this one came out of, or we'll get into a fight
704 * over who claims what Ether address.
706 if (!rt->rt_ifp || rt->rt_ifp == ifp) {
710 IF_AFDATA_LOCK(rt->rt_ifp);
711 lle = lla_lookup(LLTABLE(rt->rt_ifp), 0, (struct sockaddr *)&sin);
712 IF_AFDATA_UNLOCK(rt->rt_ifp);
716 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
717 (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln);
723 * Also check that the node which sent the ARP packet
724 * is on the the interface we expect it to be on. This
725 * avoids ARP chaos if an interface is connected to the
728 sin.sin_addr = isaddr;
730 /* XXX MRT use table 0 for arp checks */
731 rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0);
734 if (rt->rt_ifp != ifp) {
735 log(LOG_INFO, "arp_proxy: ignoring request"
736 " from %s via %s, expecting %s\n",
737 inet_ntoa(isaddr), ifp->if_xname,
738 rt->rt_ifp->if_xname);
745 printf("arp: proxying for %s\n",
752 if (itaddr.s_addr == myaddr.s_addr &&
753 IN_LINKLOCAL(ntohl(itaddr.s_addr))) {
754 /* RFC 3927 link-local IPv4; always reply by broadcast. */
755 #ifdef DEBUG_LINKLOCAL
756 printf("arp: sending reply for link-local addr %s\n",
759 m->m_flags |= M_BCAST;
760 m->m_flags &= ~M_MCAST;
762 /* default behaviour; never reply by broadcast. */
763 m->m_flags &= ~(M_BCAST|M_MCAST);
765 (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
766 (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
767 ah->ar_op = htons(ARPOP_REPLY);
768 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
769 m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln);
770 m->m_pkthdr.len = m->m_len;
771 sa.sa_family = AF_ARP;
773 (*ifp->if_output)(ifp, m, &sa, NULL);
784 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
788 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) {
789 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
790 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
792 * interface address is considered static entry
793 * because the output of the arp utility shows
794 * that L2 entry as permanent
797 lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC),
798 (struct sockaddr *)IA_SIN(ifa));
799 IF_AFDATA_UNLOCK(ifp);
801 log(LOG_INFO, "arp_ifinit: cannot create arp "
802 "entry for interface address\n");
806 ifa->ifa_rtrequest = NULL;
810 arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr)
812 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
813 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
814 &IA_SIN(ifa)->sin_addr, enaddr);
815 ifa->ifa_rtrequest = NULL;
819 arp_iattach(const void *unused __unused)
821 INIT_VNET_INET(curvnet);
823 V_arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
825 V_useloopback = 1; /* use loopback interface for local traffic */
835 #ifndef VIMAGE_GLOBALS
836 vnet_mod_register(&vnet_arp_modinfo);
841 netisr_register(&arp_nh);
843 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);