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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93
34 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $
35 * $DragonFly: src/sys/netinet/if_ether.c,v 1.13 2004/06/02 14:43:01 eirikn Exp $
39 * Ethernet address resolution protocol.
41 * add "inuse/lock" bit (or ref. count) along with valid bit
47 #include <sys/param.h>
48 #include <sys/kernel.h>
49 #include <sys/queue.h>
50 #include <sys/sysctl.h>
51 #include <sys/systm.h>
53 #include <sys/malloc.h>
54 #include <sys/socket.h>
55 #include <sys/syslog.h>
57 #include <sys/thread2.h>
58 #include <sys/msgport2.h>
61 #include <net/if_dl.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 #include <net/netisr.h>
65 #include <net/if_llc.h>
67 #include <net/ethernet.h>
68 #include <net/bridge/bridge.h>
71 #include <netinet/in.h>
72 #include <netinet/in_var.h>
73 #include <netinet/if_ether.h>
75 #include <net/if_arc.h>
76 #include <net/iso88025.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, "");
85 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
86 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
87 static int arpt_down = 20; /* once declared down, don't send for 20 sec */
89 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
91 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
93 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW,
96 #define rt_expire rt_rmx.rmx_expire
99 LIST_ENTRY(llinfo_arp) la_le;
100 struct rtentry *la_rt;
101 struct mbuf *la_hold; /* last packet until resolved/timeout */
102 u_short la_preempt; /* #times we QUERIED before entry expiration */
103 u_short la_asked; /* #times we QUERIED following expiration */
104 #define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */
107 static LIST_HEAD(, llinfo_arp) llinfo_arp;
109 static int arp_inuse, arp_allocated, arpinit_done;
111 static int arp_maxtries = 5;
112 static int useloopback = 1; /* use loopback interface for local traffic */
113 static int arp_proxyall = 0;
115 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
116 &arp_maxtries, 0, "");
117 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
118 &useloopback, 0, "");
119 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
120 &arp_proxyall, 0, "");
122 static void arp_rtrequest (int, struct rtentry *, struct rt_addrinfo *);
123 static void arprequest (struct ifnet *,
124 struct in_addr *, struct in_addr *, u_char *);
125 static int arpintr(struct netmsg *);
126 static void arptfree (struct llinfo_arp *);
127 static void arptimer (void *);
128 static struct llinfo_arp
129 *arplookup (u_long, int, int);
131 static void in_arpinput (struct mbuf *);
134 u_char arcbroadcastaddr = 0;
136 #define IF_BCASTADDR(ifp) \
137 ((ifp)->if_type == IFT_ARCNET ? \
138 &arcbroadcastaddr : etherbroadcastaddr)
141 * Timeout routine. Age arp_tab entries periodically.
145 arptimer(ignored_arg)
149 struct llinfo_arp *la = LIST_FIRST(&llinfo_arp);
150 struct llinfo_arp *ola;
152 timeout(arptimer, (caddr_t)0, arpt_prune * hz);
153 while ((ola = la) != 0) {
154 struct rtentry *rt = la->la_rt;
155 la = LIST_NEXT(la, la_le);
156 if (rt->rt_expire && rt->rt_expire <= time_second)
157 arptfree(ola); /* timer has expired, clear */
163 * Parallel to llc_rtrequest.
166 arp_rtrequest(req, rt, info)
169 struct rt_addrinfo *info;
171 struct sockaddr *gate = rt->rt_gateway;
172 struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
173 static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
177 timeout(arptimer, (caddr_t)0, hz);
179 if (rt->rt_flags & RTF_GATEWAY)
185 * XXX: If this is a manually added route to interface
186 * such as older version of routed or gated might provide,
187 * restore cloning bit.
189 if ((rt->rt_flags & RTF_HOST) == 0 &&
190 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
191 rt->rt_flags |= RTF_CLONING;
192 if (rt->rt_flags & RTF_CLONING) {
194 * Case 1: This route should come from a route to iface.
196 rt_setgate(rt, rt_key(rt),
197 (struct sockaddr *)&null_sdl);
198 gate = rt->rt_gateway;
199 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
200 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
201 rt->rt_expire = time_second;
204 /* Announce a new entry if requested. */
205 if (rt->rt_flags & RTF_ANNOUNCE)
206 arprequest(rt->rt_ifp,
207 &SIN(rt_key(rt))->sin_addr,
208 &SIN(rt_key(rt))->sin_addr,
209 (u_char *)LLADDR(SDL(gate)));
212 if (gate->sa_family != AF_LINK ||
213 gate->sa_len < sizeof(null_sdl)) {
214 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
217 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
218 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
220 break; /* This happens on a route change */
222 * Case 2: This route may come from cloning, or a manual route
223 * add with a LL address.
225 R_Malloc(la, struct llinfo_arp *, sizeof(*la));
226 rt->rt_llinfo = (caddr_t)la;
228 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
231 arp_inuse++, arp_allocated++;
232 Bzero(la, sizeof(*la));
234 rt->rt_flags |= RTF_LLINFO;
235 LIST_INSERT_HEAD(&llinfo_arp, la, la_le);
239 * This keeps the multicast addresses from showing up
240 * in `arp -a' listings as unresolved. It's not actually
241 * functional. Then the same for broadcast.
243 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))
244 && rt->rt_ifp->if_type != IFT_ARCNET) {
245 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
247 SDL(gate)->sdl_alen = 6;
250 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
251 memcpy(LLADDR(SDL(gate)), IF_BCASTADDR(rt->rt_ifp),
252 rt->rt_ifp->if_addrlen);
253 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen;
258 if (SIN(rt_key(rt))->sin_addr.s_addr ==
259 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
261 * This test used to be
262 * if (loif.if_flags & IFF_UP)
263 * It allowed local traffic to be forced
264 * through the hardware by configuring the loopback down.
265 * However, it causes problems during network configuration
266 * for boards that can't receive packets they send.
267 * It is now necessary to clear "useloopback" and remove
268 * the route to force traffic out to the hardware.
271 Bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)),
272 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen);
283 LIST_REMOVE(la, la_le);
285 rt->rt_flags &= ~RTF_LLINFO;
287 m_freem(la->la_hold);
293 * Broadcast an ARP request. Caller specifies:
294 * - arp header source ip address
295 * - arp header target ip address
296 * - arp header source ethernet address
299 arprequest(ifp, sip, tip, enaddr)
301 struct in_addr *sip, *tip;
305 struct ether_header *eh;
306 struct arc_header *arh;
309 static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP,
310 LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 };
313 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL)
315 m->m_pkthdr.rcvif = (struct ifnet *)0;
316 switch (ifp->if_type) {
318 ar_hrd = htons(ARPHRD_ARCNET);
320 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
321 m->m_pkthdr.len = m->m_len;
322 MH_ALIGN(m, m->m_len);
324 arh = (struct arc_header *)sa.sa_data;
325 arh->arc_dhost = arcbroadcastaddr;
326 arh->arc_type = ARCTYPE_ARP;
328 ah = mtod(m, struct arphdr *);
332 ar_hrd = htons(ARPHRD_IEEE802);
334 m->m_len = sizeof(llcx) +
335 arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
336 m->m_pkthdr.len = m->m_len;
337 MH_ALIGN(m, m->m_len);
339 (void)memcpy(mtod(m, caddr_t), llcx, sizeof(llcx));
340 (void)memcpy(sa.sa_data, etherbroadcastaddr, 6);
341 (void)memcpy(sa.sa_data + 6, enaddr, 6);
342 sa.sa_data[6] |= TR_RII;
343 sa.sa_data[12] = TR_AC;
344 sa.sa_data[13] = TR_LLC_FRAME;
346 ah = (struct arphdr *)(mtod(m, char *) + sizeof(llcx));
351 * This may not be correct for types not explicitly
352 * listed, but this is our best guess
355 ar_hrd = htons(ARPHRD_ETHER);
357 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
358 m->m_pkthdr.len = m->m_len;
359 MH_ALIGN(m, m->m_len);
361 eh = (struct ether_header *)sa.sa_data;
362 /* if_output will not swap */
363 eh->ether_type = htons(ETHERTYPE_ARP);
364 (void)memcpy(eh->ether_dhost, etherbroadcastaddr,
365 sizeof(eh->ether_dhost));
367 ah = mtod(m, struct arphdr *);
372 ah->ar_pro = htons(ETHERTYPE_IP);
373 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
374 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
375 ah->ar_op = htons(ARPOP_REQUEST);
376 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
377 memset(ar_tha(ah), 0, ah->ar_hln);
378 (void)memcpy(ar_spa(ah), sip, ah->ar_pln);
379 (void)memcpy(ar_tpa(ah), tip, ah->ar_pln);
381 sa.sa_family = AF_UNSPEC;
382 sa.sa_len = sizeof(sa);
383 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
387 * Resolve an IP address into an ethernet address. If success,
388 * desten is filled in. If there is no entry in arptab,
389 * set one up and broadcast a request for the IP address.
390 * Hold onto this mbuf and resend it once the address
391 * is finally resolved. A return value of 1 indicates
392 * that desten has been filled in and the packet should be sent
393 * normally; a 0 return indicates that the packet has been
394 * taken over here, either now or for later transmission.
397 arpresolve(ifp, rt, m, dst, desten, rt0)
401 struct sockaddr *dst;
405 struct llinfo_arp *la = 0;
406 struct sockaddr_dl *sdl;
408 if (m->m_flags & M_BCAST) { /* broadcast */
409 (void)memcpy(desten, IF_BCASTADDR(ifp), ifp->if_addrlen);
412 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */
413 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
417 la = (struct llinfo_arp *)rt->rt_llinfo;
419 la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
423 if (la == 0 || rt == 0) {
424 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n",
425 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "",
430 sdl = SDL(rt->rt_gateway);
432 * Check the address family and length is valid, the address
433 * is resolved; otherwise, try to resolve.
435 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) &&
436 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
438 * If entry has an expiry time and it is approaching,
439 * see if we need to send an ARP request within this
440 * arpt_down interval.
442 if ((rt->rt_expire != 0) &&
443 (time_second + (arp_maxtries - la->la_preempt) * arpt_down
446 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
452 bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
456 * If ARP is disabled on this interface, stop.
458 * Probably should not allocate empty llinfo struct if we are
459 * not going to be sending out an arp request.
461 if (ifp->if_flags & IFF_NOARP) {
466 * There is an arptab entry, but no ethernet address
467 * response yet. Replace the held mbuf with this
471 m_freem(la->la_hold);
474 rt->rt_flags &= ~RTF_REJECT;
475 if (la->la_asked == 0 || rt->rt_expire != time_second) {
476 rt->rt_expire = time_second;
477 if (la->la_asked++ < arp_maxtries) {
479 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
483 rt->rt_flags |= RTF_REJECT;
484 rt->rt_expire += arpt_down;
485 la->la_preempt = la->la_asked = 0;
494 * Common length and type checks are done here,
495 * then the protocol-specific routine is called.
498 arpintr(struct netmsg *msg)
500 struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
504 if (m->m_len < sizeof(struct arphdr) &&
505 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
506 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
509 ar = mtod(m, struct arphdr *);
511 ar_hrd = ntohs(ar->ar_hrd);
512 if (ar_hrd != ARPHRD_ETHER &&
513 ar_hrd != ARPHRD_IEEE802 &&
514 ar_hrd != ARPHRD_ARCNET) {
516 "arp: unknown hardware address format (0x%2D)\n",
517 (unsigned char *)&ar->ar_hrd, "");
521 if (m->m_pkthdr.len < arphdr_len(ar) &&
522 (m = m_pullup(m, arphdr_len(ar))) == NULL) {
523 log(LOG_ERR, "arp: runt packet\n");
527 switch (ntohs(ar->ar_pro)) {
537 lwkt_replymsg(&msg->nm_lmsg, 0);
543 * ARP for Internet protocols on 10 Mb/s Ethernet.
544 * Algorithm is that given in RFC 826.
545 * In addition, a sanity check is performed on the sender
546 * protocol address, to catch impersonators.
547 * We no longer handle negotiations for use of trailer protocol:
548 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
549 * along with IP replies if we wanted trailers sent to us,
550 * and also sent them in response to IP replies.
551 * This allowed either end to announce the desire to receive
553 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
554 * but formerly didn't normally send requests.
556 static int log_arp_wrong_iface = 1;
558 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
559 &log_arp_wrong_iface, 0,
560 "log arp packets arriving on the wrong interface");
567 struct ifnet *ifp = m->m_pkthdr.rcvif;
568 struct ether_header *eh;
569 struct arc_header *arh;
570 struct iso88025_header *th = (struct iso88025_header *)0;
571 struct iso88025_sockaddr_dl_data *trld;
572 struct llinfo_arp *la = 0;
575 struct in_ifaddr *ia;
576 struct sockaddr_dl *sdl;
578 struct in_addr isaddr, itaddr, myaddr;
582 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
583 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
584 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
588 ah = mtod(m, struct arphdr *);
589 op = ntohs(ah->ar_op);
590 (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
591 (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
593 #define BRIDGE_TEST (do_bridge)
595 #define BRIDGE_TEST (0) /* cc will optimise the test away */
598 * For a bridge, we want to check the address irrespective
599 * of the receive interface. (This will change slightly
600 * when we have clusters of interfaces).
602 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash)
603 if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
604 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
606 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
607 if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
608 isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
611 * No match, use the first inet address on the receive interface
612 * as a dummy address for the rest of the function.
614 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
615 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
620 * If bridging, fall back to using any inet address.
621 * This is probably incorrect, the right way being try to match
622 * addresses for interfaces in the same cluster, so if we
623 * get here we should always drop the packet.
626 (ia = TAILQ_FIRST(&in_ifaddrhead)) == NULL) {
631 myaddr = ia->ia_addr.sin_addr;
632 if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) {
633 m_freem(m); /* it's from me, ignore it. */
636 if (!bcmp(ar_sha(ah), IF_BCASTADDR(ifp), ifp->if_addrlen)) {
638 "arp: link address is broadcast for IP address %s!\n",
643 if (isaddr.s_addr == myaddr.s_addr) {
645 "arp: %*D is using my IP address %s!\n",
646 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
651 la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
652 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
653 /* the following is not an error when doing bridging */
654 if (!BRIDGE_TEST && rt->rt_ifp != ifp) {
655 if (log_arp_wrong_iface)
656 log(LOG_ERR, "arp: %s is on %s but got reply from %*D on %s\n",
658 rt->rt_ifp->if_xname,
659 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
664 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
666 log(LOG_INFO, "arp: %s moved from %*D to %*D on %s\n",
668 ifp->if_addrlen, (u_char *)LLADDR(sdl), ":",
669 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
673 "arp: %*D attempts to modify permanent entry for %s on %s\n",
674 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
675 inet_ntoa(isaddr), ifp->if_xname);
680 * sanity check for the address length.
681 * XXX this does not work for protocols with variable address
685 sdl->sdl_alen != ah->ar_hln) {
687 "arp from %*D: new addr len %d, was %d",
688 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
689 ah->ar_hln, sdl->sdl_alen);
691 if (ifp->if_addrlen != ah->ar_hln) {
693 "arp from %*D: addr len: new %d, i/f %d (ignored)",
694 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
695 ah->ar_hln, ifp->if_addrlen);
698 (void)memcpy(LLADDR(sdl), ar_sha(ah),
699 sdl->sdl_alen = ah->ar_hln);
701 * If we receive an arp from a token-ring station over
702 * a token-ring nic then try to save the source
705 if (ifp->if_type == IFT_ISO88025) {
706 th = (struct iso88025_header *)m->m_pkthdr.header;
707 trld = SDL_ISO88025(sdl);
708 rif_len = TR_RCF_RIFLEN(th->rcf);
709 if ((th->iso88025_shost[0] & TR_RII) &&
711 trld->trld_rcf = th->rcf;
712 trld->trld_rcf ^= htons(TR_RCF_DIR);
713 memcpy(trld->trld_route, th->rd, rif_len - 2);
714 trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK);
716 * Set up source routing information for
719 m->m_data -= rif_len;
721 m->m_pkthdr.len += rif_len;
723 th->iso88025_shost[0] &= ~TR_RII;
728 m->m_pkthdr.len += 8;
729 th->rcf = trld->trld_rcf;
732 rt->rt_expire = time_second + arpt_keep;
733 rt->rt_flags &= ~RTF_REJECT;
734 la->la_preempt = la->la_asked = 0;
736 (*ifp->if_output)(ifp, la->la_hold,
742 if (op != ARPOP_REQUEST) {
746 if (itaddr.s_addr == myaddr.s_addr) {
747 /* I am the target */
748 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
749 (void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
751 la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
753 struct sockaddr_in sin;
760 bzero(&sin, sizeof sin);
761 sin.sin_family = AF_INET;
762 sin.sin_len = sizeof sin;
763 sin.sin_addr = itaddr;
765 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
771 * Don't send proxies for nodes on the same interface
772 * as this one came out of, or we'll get into a fight
773 * over who claims what Ether address.
775 if (rt->rt_ifp == ifp) {
780 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
781 (void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
784 printf("arp: proxying for %s\n",
789 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
790 sdl = SDL(rt->rt_gateway);
791 (void)memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
795 (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
796 (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
797 ah->ar_op = htons(ARPOP_REPLY);
798 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
799 switch (ifp->if_type) {
801 arh = (struct arc_header *)sa.sa_data;
802 arh->arc_dhost = *ar_tha(ah);
803 arh->arc_type = ARCTYPE_ARP;
807 /* Re-arrange the source/dest address */
808 memcpy(th->iso88025_dhost, th->iso88025_shost,
809 sizeof(th->iso88025_dhost));
810 memcpy(th->iso88025_shost, IF_LLADDR(ifp),
811 sizeof(th->iso88025_shost));
812 /* Set the source routing bit if neccesary */
813 if (th->iso88025_dhost[0] & TR_RII) {
814 th->iso88025_dhost[0] &= ~TR_RII;
815 if (TR_RCF_RIFLEN(th->rcf) > 2)
816 th->iso88025_shost[0] |= TR_RII;
818 /* Copy the addresses, ac and fc into sa_data */
819 memcpy(sa.sa_data, th->iso88025_dhost,
820 sizeof(th->iso88025_dhost) * 2);
821 sa.sa_data[(sizeof(th->iso88025_dhost) * 2)] = TR_AC;
822 sa.sa_data[(sizeof(th->iso88025_dhost) * 2) + 1] = TR_LLC_FRAME;
827 * May not be correct for types not explictly
828 * listed, but it is our best guess.
831 eh = (struct ether_header *)sa.sa_data;
832 (void)memcpy(eh->ether_dhost, ar_tha(ah),
833 sizeof(eh->ether_dhost));
834 eh->ether_type = htons(ETHERTYPE_ARP);
837 sa.sa_family = AF_UNSPEC;
838 sa.sa_len = sizeof(sa);
839 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
849 struct llinfo_arp *la;
851 struct rtentry *rt = la->la_rt;
852 struct sockaddr_dl *sdl;
855 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
856 sdl->sdl_family == AF_LINK) {
858 la->la_preempt = la->la_asked = 0;
859 rt->rt_flags &= ~RTF_REJECT;
862 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
863 0, (struct rtentry **)0);
866 * Lookup or enter a new address in arptab.
868 static struct llinfo_arp *
869 arplookup(addr, create, proxy)
874 static struct sockaddr_inarp sin = {sizeof(sin), AF_INET };
877 sin.sin_addr.s_addr = addr;
878 sin.sin_other = proxy ? SIN_PROXY : 0;
879 rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
884 if (rt->rt_flags & RTF_GATEWAY)
885 why = "host is not on local network";
886 else if ((rt->rt_flags & RTF_LLINFO) == 0)
887 why = "could not allocate llinfo";
888 else if (rt->rt_gateway->sa_family != AF_LINK)
889 why = "gateway route is not ours";
893 log(LOG_DEBUG, "arplookup %s failed: %s\n",
894 inet_ntoa(sin.sin_addr), why);
897 /* if there are no references to this route, purge it */
898 if (rt->rt_refcnt <= 0 &&
899 (rt->rt_flags & RTF_WASCLONED) == RTF_WASCLONED) {
900 rtrequest(RTM_DELETE,
901 (struct sockaddr *)rt_key(rt), rt->rt_gateway,
902 rt_mask(rt), rt->rt_flags, 0);
906 return ((struct llinfo_arp *)rt->rt_llinfo);
914 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
915 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
916 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
917 ifa->ifa_rtrequest = arp_rtrequest;
918 ifa->ifa_flags |= RTF_CLONING;
924 LIST_INIT(&llinfo_arp);
925 netisr_register(NETISR_ARP, cpu0_portfn, arpintr);
928 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);