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
38 * Ethernet address resolution protocol.
40 * 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>
54 #include <sys/malloc.h>
55 #include <sys/socket.h>
56 #include <sys/syslog.h>
59 #include <net/if_dl.h>
60 #include <net/if_types.h>
61 #include <net/route.h>
62 #include <net/netisr.h>
63 #include <net/if_llc.h>
65 #include <net/ethernet.h>
66 #include <net/bridge.h>
69 #include <netinet/in.h>
70 #include <netinet/in_var.h>
71 #include <netinet/if_ether.h>
73 #include <net/if_arc.h>
74 #include <net/iso88025.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, "");
83 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
84 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
85 static int arpt_down = 20; /* once declared down, don't send for 20 sec */
87 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
89 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
91 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW,
94 #define rt_expire rt_rmx.rmx_expire
97 LIST_ENTRY(llinfo_arp) la_le;
98 struct rtentry *la_rt;
99 struct mbuf *la_hold; /* last packet until resolved/timeout */
100 long la_asked; /* last time we QUERIED for this addr */
101 #define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */
104 static LIST_HEAD(, llinfo_arp) llinfo_arp;
106 struct ifqueue arpintrq;
107 static int arp_inuse, arp_allocated, arpinit_done;
109 static int arp_maxtries = 5;
110 static int useloopback = 1; /* use loopback interface for local traffic */
111 static int arp_proxyall = 0;
113 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
114 &arp_maxtries, 0, "");
115 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
116 &useloopback, 0, "");
117 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
118 &arp_proxyall, 0, "");
120 static void arp_init(void);
121 static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
122 static void arprequest(struct ifnet *,
123 struct in_addr *, struct in_addr *, u_char *);
124 static void arpintr(void);
125 static void arptfree(struct llinfo_arp *);
126 static void arptimer(void *);
127 static struct llinfo_arp
128 *arplookup(u_long, int, int);
130 static void in_arpinput(struct mbuf *);
134 * Timeout routine. Age arp_tab entries periodically.
138 arptimer(ignored_arg)
142 register struct llinfo_arp *la = LIST_FIRST(&llinfo_arp);
143 struct llinfo_arp *ola;
145 timeout(arptimer, (caddr_t)0, arpt_prune * hz);
146 while ((ola = la) != 0) {
147 register struct rtentry *rt = la->la_rt;
148 la = LIST_NEXT(la, la_le);
149 if (rt->rt_expire && rt->rt_expire <= time_second)
150 arptfree(ola); /* timer has expired, clear */
156 * Parallel to llc_rtrequest.
159 arp_rtrequest(req, rt, info)
161 register struct rtentry *rt;
162 struct rt_addrinfo *info;
164 register struct sockaddr *gate = rt->rt_gateway;
165 register struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo;
166 static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
170 timeout(arptimer, (caddr_t)0, hz);
172 if (rt->rt_flags & RTF_GATEWAY)
178 * XXX: If this is a manually added route to interface
179 * such as older version of routed or gated might provide,
180 * restore cloning bit.
182 if ((rt->rt_flags & RTF_HOST) == 0 &&
183 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
184 rt->rt_flags |= RTF_CLONING;
185 if (rt->rt_flags & RTF_CLONING) {
187 * Case 1: This route should come from a route to iface.
189 rt_setgate(rt, rt_key(rt),
190 (struct sockaddr *)&null_sdl);
191 gate = rt->rt_gateway;
192 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
193 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
194 rt->rt_expire = time_second;
197 /* Announce a new entry if requested. */
198 if (rt->rt_flags & RTF_ANNOUNCE)
199 arprequest(rt->rt_ifp,
200 &SIN(rt_key(rt))->sin_addr,
201 &SIN(rt_key(rt))->sin_addr,
202 (u_char *)LLADDR(SDL(gate)));
205 if (gate->sa_family != AF_LINK ||
206 gate->sa_len < sizeof(null_sdl)) {
207 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
210 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
211 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
213 break; /* This happens on a route change */
215 * Case 2: This route may come from cloning, or a manual route
216 * add with a LL address.
218 R_Malloc(la, struct llinfo_arp *, sizeof(*la));
219 rt->rt_llinfo = (caddr_t)la;
221 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
224 arp_inuse++, arp_allocated++;
225 Bzero(la, sizeof(*la));
227 rt->rt_flags |= RTF_LLINFO;
228 LIST_INSERT_HEAD(&llinfo_arp, la, la_le);
232 * This keeps the multicast addresses from showing up
233 * in `arp -a' listings as unresolved. It's not actually
234 * functional. Then the same for broadcast.
236 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) &&
237 rt->rt_ifp->if_type != IFT_ARCNET) {
238 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
240 SDL(gate)->sdl_alen = 6;
243 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
244 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr,
245 rt->rt_ifp->if_addrlen);
246 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen;
251 if (SIN(rt_key(rt))->sin_addr.s_addr ==
252 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
254 * This test used to be
255 * if (loif.if_flags & IFF_UP)
256 * It allowed local traffic to be forced
257 * through the hardware by configuring the loopback down.
258 * However, it causes problems during network configuration
259 * for boards that can't receive packets they send.
260 * It is now necessary to clear "useloopback" and remove
261 * the route to force traffic out to the hardware.
264 Bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)),
265 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen);
276 LIST_REMOVE(la, la_le);
278 rt->rt_flags &= ~RTF_LLINFO;
280 m_freem(la->la_hold);
286 * Broadcast an ARP request. Caller specifies:
287 * - arp header source ip address
288 * - arp header target ip address
289 * - arp header source ethernet address
292 arprequest(ifp, sip, tip, enaddr)
293 register struct ifnet *ifp;
294 register struct in_addr *sip, *tip;
295 register u_char *enaddr;
297 register struct mbuf *m;
298 register struct ether_header *eh;
299 register struct arc_header *arh;
300 register struct arphdr *ah;
302 static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP,
303 LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 };
306 if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
308 m->m_pkthdr.rcvif = (struct ifnet *)0;
310 mac_create_mbuf_linklayer(ifp, m);
312 switch (ifp->if_type) {
314 ar_hrd = htons(ARPHRD_ARCNET);
316 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
317 m->m_pkthdr.len = m->m_len;
318 MH_ALIGN(m, m->m_len);
320 arh = (struct arc_header *)sa.sa_data;
321 arh->arc_dhost = *ifp->if_broadcastaddr;
322 arh->arc_type = ARCTYPE_ARP;
324 ah = mtod(m, struct arphdr *);
328 ar_hrd = htons(ARPHRD_IEEE802);
330 m->m_len = sizeof(llcx) +
331 arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
332 m->m_pkthdr.len = m->m_len;
333 MH_ALIGN(m, m->m_len);
335 (void)memcpy(mtod(m, caddr_t), llcx, sizeof(llcx));
336 (void)memcpy(sa.sa_data, ifp->if_broadcastaddr, 6);
337 (void)memcpy(sa.sa_data + 6, enaddr, 6);
338 sa.sa_data[6] |= TR_RII;
339 sa.sa_data[12] = TR_AC;
340 sa.sa_data[13] = TR_LLC_FRAME;
342 ah = (struct arphdr *)(mtod(m, char *) + sizeof(llcx));
347 * This may not be correct for types not explicitly
348 * listed, but this is our best guess
351 ar_hrd = htons(ARPHRD_ETHER);
353 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
354 m->m_pkthdr.len = m->m_len;
355 MH_ALIGN(m, m->m_len);
357 eh = (struct ether_header *)sa.sa_data;
358 /* if_output will not swap */
359 eh->ether_type = htons(ETHERTYPE_ARP);
360 (void)memcpy(eh->ether_dhost, ifp->if_broadcastaddr,
361 sizeof(eh->ether_dhost));
363 ah = mtod(m, struct arphdr *);
368 ah->ar_pro = htons(ETHERTYPE_IP);
369 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
370 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
371 ah->ar_op = htons(ARPOP_REQUEST);
372 (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln);
373 (void)memcpy(ar_spa(ah), sip, ah->ar_pln);
374 (void)memcpy(ar_tpa(ah), tip, ah->ar_pln);
376 sa.sa_family = AF_UNSPEC;
377 sa.sa_len = sizeof(sa);
378 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
382 * Resolve an IP address into an ethernet address. If success,
383 * desten is filled in. If there is no entry in arptab,
384 * set one up and broadcast a request for the IP address.
385 * Hold onto this mbuf and resend it once the address
386 * is finally resolved. A return value of 1 indicates
387 * that desten has been filled in and the packet should be sent
388 * normally; a 0 return indicates that the packet has been
389 * taken over here, either now or for later transmission.
392 arpresolve(ifp, rt, m, dst, desten, rt0)
393 register struct ifnet *ifp;
394 register struct rtentry *rt;
396 register struct sockaddr *dst;
397 register u_char *desten;
400 struct llinfo_arp *la = 0;
401 struct sockaddr_dl *sdl;
403 if (m->m_flags & M_BCAST) { /* broadcast */
404 (void)memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
407 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */
408 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
412 la = (struct llinfo_arp *)rt->rt_llinfo;
414 la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0);
418 if (la == 0 || rt == 0) {
419 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n",
420 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "",
425 sdl = SDL(rt->rt_gateway);
427 * Check the address family and length is valid, the address
428 * is resolved; otherwise, try to resolve.
430 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) &&
431 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
433 * If entry has an expiry time and it is approaching,
434 * see if we need to send an ARP request within this
435 * arpt_down interval.
437 if ((rt->rt_expire != 0) &&
438 (time_second + (arp_maxtries - la->la_asked) * arpt_down >
441 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
447 bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
451 * If ARP is disabled on this interface, stop.
453 * Probably should not allocate empty llinfo struct if we are
454 * not going to be sending out an arp request.
456 if (ifp->if_flags & IFF_NOARP) {
461 * There is an arptab entry, but no ethernet address
462 * response yet. Replace the held mbuf with this
466 m_freem(la->la_hold);
469 rt->rt_flags &= ~RTF_REJECT;
470 if (la->la_asked == 0 || rt->rt_expire != time_second) {
471 rt->rt_expire = time_second;
472 if (la->la_asked++ < arp_maxtries)
474 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
478 rt->rt_flags |= RTF_REJECT;
479 rt->rt_expire += arpt_down;
489 * Common length and type checks are done here,
490 * then the protocol-specific routine is called.
495 register struct mbuf *m;
496 register struct arphdr *ar;
501 timeout(arptimer, (caddr_t)0, hz);
503 while (arpintrq.ifq_head) {
505 IF_DEQUEUE(&arpintrq, m);
507 if (m == 0 || (m->m_flags & M_PKTHDR) == 0)
510 if (m->m_len < sizeof(struct arphdr) &&
511 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
512 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
515 ar = mtod(m, struct arphdr *);
517 if (ntohs(ar->ar_hrd) != ARPHRD_ETHER
518 && ntohs(ar->ar_hrd) != ARPHRD_IEEE802
519 && ntohs(ar->ar_hrd) != ARPHRD_ARCNET) {
521 "arp: unknown hardware address format (0x%2D)\n",
522 (unsigned char *)&ar->ar_hrd, "");
527 if (m->m_pkthdr.len < arphdr_len(ar) &&
528 (m = m_pullup(m, arphdr_len(ar))) == NULL) {
529 log(LOG_ERR, "arp: runt packet\n");
534 switch (ntohs(ar->ar_pro)) {
547 * ARP for Internet protocols on 10 Mb/s Ethernet.
548 * Algorithm is that given in RFC 826.
549 * In addition, a sanity check is performed on the sender
550 * protocol address, to catch impersonators.
551 * We no longer handle negotiations for use of trailer protocol:
552 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
553 * along with IP replies if we wanted trailers sent to us,
554 * and also sent them in response to IP replies.
555 * This allowed either end to announce the desire to receive
557 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
558 * but formerly didn't normally send requests.
560 static int log_arp_wrong_iface = 1;
561 static int log_arp_movements = 1;
563 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
564 &log_arp_wrong_iface, 0,
565 "log arp packets arriving on the wrong interface");
566 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
567 &log_arp_movements, 0,
568 "log arp replies from MACs different than the one in the cache");
575 register struct arphdr *ah;
576 register struct ifnet *ifp = m->m_pkthdr.rcvif;
577 struct ether_header *eh;
578 struct arc_header *arh;
579 struct iso88025_header *th = (struct iso88025_header *)0;
580 struct iso88025_sockaddr_dl_data *trld;
581 register struct llinfo_arp *la = 0;
582 register struct rtentry *rt;
584 struct in_ifaddr *ia;
585 struct sockaddr_dl *sdl;
587 struct in_addr isaddr, itaddr, myaddr;
591 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
592 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
593 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
597 ah = mtod(m, struct arphdr *);
598 op = ntohs(ah->ar_op);
599 (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr));
600 (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr));
602 #define BRIDGE_TEST (do_bridge)
604 #define BRIDGE_TEST (0) /* cc will optimise the test away */
607 * For a bridge, we want to check the address irrespective
608 * of the receive interface. (This will change slightly
609 * when we have clusters of interfaces).
611 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash)
612 if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
613 itaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
615 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash)
616 if ((BRIDGE_TEST || (ia->ia_ifp == ifp)) &&
617 isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)
620 * No match, use the first inet address on the receive interface
621 * as a dummy address for the rest of the function.
623 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
624 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
629 * If bridging, fall back to using any inet address.
632 (ia = TAILQ_FIRST(&in_ifaddrhead)) == NULL) {
637 myaddr = ia->ia_addr.sin_addr;
638 if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) {
639 m_freem(m); /* it's from me, ignore it. */
642 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
644 "arp: link address is broadcast for IP address %s!\n",
649 if (isaddr.s_addr == myaddr.s_addr) {
651 "arp: %*D is using my IP address %s!\n",
652 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
657 la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0);
658 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
659 /* the following is not an error when doing bridging */
660 if (!BRIDGE_TEST && rt->rt_ifp != ifp) {
661 if (log_arp_wrong_iface)
662 log(LOG_ERR, "arp: %s is on %s%d but got reply from %*D on %s%d\n",
664 rt->rt_ifp->if_name, rt->rt_ifp->if_unit,
665 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
666 ifp->if_name, ifp->if_unit);
670 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
672 if (log_arp_movements)
673 log(LOG_INFO, "arp: %s moved from %*D to %*D on %s%d\n",
675 ifp->if_addrlen, (u_char *)LLADDR(sdl), ":",
676 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
677 ifp->if_name, ifp->if_unit);
680 "arp: %*D attempts to modify permanent entry for %s on %s%d\n",
681 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
682 inet_ntoa(isaddr), ifp->if_name, ifp->if_unit);
687 * sanity check for the address length.
688 * XXX this does not work for protocols with variable address
692 sdl->sdl_alen != ah->ar_hln) {
694 "arp from %*D: new addr len %d, was %d",
695 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
696 ah->ar_hln, sdl->sdl_alen);
698 if (ifp->if_addrlen != ah->ar_hln) {
700 "arp from %*D: addr len: new %d, i/f %d (ignored)",
701 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
702 ah->ar_hln, ifp->if_addrlen);
705 (void)memcpy(LLADDR(sdl), ar_sha(ah),
706 sdl->sdl_alen = ah->ar_hln);
708 * If we receive an arp from a token-ring station over
709 * a token-ring nic then try to save the source
712 if (ifp->if_type == IFT_ISO88025) {
713 th = (struct iso88025_header *)m->m_pkthdr.header;
714 trld = SDL_ISO88025(sdl);
715 rif_len = TR_RCF_RIFLEN(th->rcf);
716 if ((th->iso88025_shost[0] & TR_RII) &&
718 trld->trld_rcf = th->rcf;
719 trld->trld_rcf ^= htons(TR_RCF_DIR);
720 memcpy(trld->trld_route, th->rd, rif_len - 2);
721 trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK);
723 * Set up source routing information for
726 m->m_data -= rif_len;
728 m->m_pkthdr.len += rif_len;
730 th->iso88025_shost[0] &= ~TR_RII;
735 m->m_pkthdr.len += 8;
736 th->rcf = trld->trld_rcf;
739 rt->rt_expire = time_second + arpt_keep;
740 rt->rt_flags &= ~RTF_REJECT;
743 (*ifp->if_output)(ifp, la->la_hold,
749 if (op != ARPOP_REQUEST) {
753 if (itaddr.s_addr == myaddr.s_addr) {
754 /* I am the target */
755 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
756 (void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
758 la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
760 struct sockaddr_in sin;
767 bzero(&sin, sizeof sin);
768 sin.sin_family = AF_INET;
769 sin.sin_len = sizeof sin;
770 sin.sin_addr = itaddr;
772 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
778 * Don't send proxies for nodes on the same interface
779 * as this one came out of, or we'll get into a fight
780 * over who claims what Ether address.
782 if (rt->rt_ifp == ifp) {
787 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
788 (void)memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
792 * Also check that the node which sent the ARP packet
793 * is on the the interface we expect it to be on. This
794 * avoids ARP chaos if an interface is connected to the
797 sin.sin_addr = isaddr;
799 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
804 if (rt->rt_ifp != ifp) {
805 log(LOG_INFO, "arp_proxy: ignoring request"
806 " from %s via %s%d, expecting %s%d\n",
807 inet_ntoa(isaddr), ifp->if_name,
808 ifp->if_unit, rt->rt_ifp->if_name,
809 rt->rt_ifp->if_unit);
817 printf("arp: proxying for %s\n",
822 (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
823 sdl = SDL(rt->rt_gateway);
824 (void)memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
828 (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
829 (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
830 ah->ar_op = htons(ARPOP_REPLY);
831 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
832 switch (ifp->if_type) {
834 arh = (struct arc_header *)sa.sa_data;
835 arh->arc_dhost = *ar_tha(ah);
836 arh->arc_type = ARCTYPE_ARP;
840 /* Re-arrange the source/dest address */
841 memcpy(th->iso88025_dhost, th->iso88025_shost,
842 sizeof(th->iso88025_dhost));
843 memcpy(th->iso88025_shost, IF_LLADDR(ifp),
844 sizeof(th->iso88025_shost));
845 /* Set the source routing bit if neccesary */
846 if (th->iso88025_dhost[0] & TR_RII) {
847 th->iso88025_dhost[0] &= ~TR_RII;
848 if (TR_RCF_RIFLEN(th->rcf) > 2)
849 th->iso88025_shost[0] |= TR_RII;
851 /* Copy the addresses, ac and fc into sa_data */
852 memcpy(sa.sa_data, th->iso88025_dhost,
853 sizeof(th->iso88025_dhost) * 2);
854 sa.sa_data[(sizeof(th->iso88025_dhost) * 2)] = TR_AC;
855 sa.sa_data[(sizeof(th->iso88025_dhost) * 2) + 1] = TR_LLC_FRAME;
860 * May not be correct for types not explictly
861 * listed, but it is our best guess.
864 eh = (struct ether_header *)sa.sa_data;
865 (void)memcpy(eh->ether_dhost, ar_tha(ah),
866 sizeof(eh->ether_dhost));
867 eh->ether_type = htons(ETHERTYPE_ARP);
870 sa.sa_family = AF_UNSPEC;
871 sa.sa_len = sizeof(sa);
872 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
882 register struct llinfo_arp *la;
884 register struct rtentry *rt = la->la_rt;
885 register struct sockaddr_dl *sdl;
888 if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
889 sdl->sdl_family == AF_LINK) {
892 rt->rt_flags &= ~RTF_REJECT;
895 rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
896 0, (struct rtentry **)0);
899 * Lookup or enter a new address in arptab.
901 static struct llinfo_arp *
902 arplookup(addr, create, proxy)
906 register struct rtentry *rt;
907 static struct sockaddr_inarp sin = {sizeof(sin), AF_INET };
910 sin.sin_addr.s_addr = addr;
911 sin.sin_other = proxy ? SIN_PROXY : 0;
912 rt = rtalloc1((struct sockaddr *)&sin, create, 0UL);
917 if (rt->rt_flags & RTF_GATEWAY)
918 why = "host is not on local network";
919 else if ((rt->rt_flags & RTF_LLINFO) == 0)
920 why = "could not allocate llinfo";
921 else if (rt->rt_gateway->sa_family != AF_LINK)
922 why = "gateway route is not ours";
925 log(LOG_DEBUG, "arplookup %s failed: %s\n",
926 inet_ntoa(sin.sin_addr), why);
931 return ((struct llinfo_arp *)rt->rt_llinfo);
939 if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY)
940 arprequest(ifp, &IA_SIN(ifa)->sin_addr,
941 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
942 ifa->ifa_rtrequest = arp_rtrequest;
943 ifa->ifa_flags |= RTF_CLONING;
950 arpintrq.ifq_maxlen = 50;
951 mtx_init(&arpintrq.ifq_mtx, "arp_inq", NULL, MTX_DEF);
952 LIST_INIT(&llinfo_arp);
953 register_netisr(NETISR_ARP, arpintr);
956 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);