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4 * This code is derived from software contributed to The DragonFly Project
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65 * @(#)if_ether.c 8.1 (Berkeley) 6/10/93
66 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $
67 * $DragonFly: src/sys/netinet/if_ether.c,v 1.36 2007/03/04 18:51:59 swildner Exp $
71 * Ethernet address resolution protocol.
73 * add "inuse/lock" bit (or ref. count) along with valid bit
78 #include <sys/param.h>
79 #include <sys/kernel.h>
80 #include <sys/queue.h>
81 #include <sys/sysctl.h>
82 #include <sys/systm.h>
84 #include <sys/malloc.h>
85 #include <sys/socket.h>
86 #include <sys/syslog.h>
88 #include <sys/thread2.h>
89 #include <sys/msgport2.h>
92 #include <net/if_dl.h>
93 #include <net/if_types.h>
94 #include <net/route.h>
95 #include <net/netisr.h>
96 #include <net/if_llc.h>
98 #include <netinet/in.h>
99 #include <netinet/in_var.h>
100 #include <netinet/if_ether.h>
102 #include <net/if_arc.h>
103 #include <net/iso88025.h>
105 #define SIN(s) ((struct sockaddr_in *)s)
106 #define SDL(s) ((struct sockaddr_dl *)s)
108 SYSCTL_DECL(_net_link_ether);
109 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
112 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
113 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
114 static int arpt_down = 20; /* once declared down, don't send for 20 sec */
116 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
118 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
120 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW,
123 #define rt_expire rt_rmx.rmx_expire
126 LIST_ENTRY(llinfo_arp) la_le;
127 struct rtentry *la_rt;
128 struct mbuf *la_hold; /* last packet until resolved/timeout */
129 u_short la_preempt; /* countdown for pre-expiry arps */
130 u_short la_asked; /* #times we QUERIED following expiration */
133 static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU];
135 static int arp_maxtries = 5;
136 static int useloopback = 1; /* use loopback interface for local traffic */
137 static int arp_proxyall = 0;
139 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
140 &arp_maxtries, 0, "");
141 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
142 &useloopback, 0, "");
143 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
144 &arp_proxyall, 0, "");
146 static void arp_rtrequest (int, struct rtentry *, struct rt_addrinfo *);
147 static void arprequest (struct ifnet *,
148 struct in_addr *, struct in_addr *, u_char *);
149 static int arpintr(struct netmsg *);
150 static void arptfree (struct llinfo_arp *);
151 static void arptimer (void *);
152 static struct llinfo_arp
153 *arplookup (in_addr_t addr, boolean_t create, boolean_t proxy);
155 static void in_arpinput (struct mbuf *);
158 static struct callout arptimer_ch[MAXCPU];
161 * Timeout routine. Age arp_tab entries periodically.
165 arptimer(void *ignored_arg)
167 struct llinfo_arp *la, *nla;
170 LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) {
171 if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second)
174 callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL);
179 * Parallel to llc_rtrequest.
182 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
184 struct sockaddr *gate = rt->rt_gateway;
185 struct llinfo_arp *la = rt->rt_llinfo;
187 struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK };
188 static boolean_t arpinit_done[MAXCPU];
190 if (!arpinit_done[mycpuid]) {
191 arpinit_done[mycpuid] = TRUE;
192 callout_init(&arptimer_ch[mycpuid]);
193 callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL);
195 if (rt->rt_flags & RTF_GATEWAY)
201 * XXX: If this is a manually added route to interface
202 * such as older version of routed or gated might provide,
203 * restore cloning bit.
205 if (!(rt->rt_flags & RTF_HOST) &&
206 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
207 rt->rt_flags |= RTF_CLONING;
208 if (rt->rt_flags & RTF_CLONING) {
210 * Case 1: This route should come from a route to iface.
212 rt_setgate(rt, rt_key(rt),
213 (struct sockaddr *)&null_sdl);
214 gate = rt->rt_gateway;
215 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
216 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
217 rt->rt_expire = time_second;
220 /* Announce a new entry if requested. */
221 if (rt->rt_flags & RTF_ANNOUNCE)
222 arprequest(rt->rt_ifp,
223 &SIN(rt_key(rt))->sin_addr,
224 &SIN(rt_key(rt))->sin_addr,
228 if (gate->sa_family != AF_LINK ||
229 gate->sa_len < sizeof(struct sockaddr_dl)) {
230 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
233 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
234 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
236 break; /* This happens on a route change */
238 * Case 2: This route may come from cloning, or a manual route
239 * add with a LL address.
241 R_Malloc(la, struct llinfo_arp *, sizeof *la);
244 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
247 bzero(la, sizeof *la);
249 rt->rt_flags |= RTF_LLINFO;
250 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le);
254 * This keeps the multicast addresses from showing up
255 * in `arp -a' listings as unresolved. It's not actually
256 * functional. Then the same for broadcast.
258 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) &&
259 rt->rt_ifp->if_type != IFT_ARCNET) {
260 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
262 SDL(gate)->sdl_alen = 6;
265 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
266 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr,
267 rt->rt_ifp->if_addrlen);
268 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen;
273 if (SIN(rt_key(rt))->sin_addr.s_addr ==
274 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
276 * This test used to be
277 * if (loif.if_flags & IFF_UP)
278 * It allowed local traffic to be forced
279 * through the hardware by configuring the
280 * loopback down. However, it causes problems
281 * during network configuration for boards
282 * that can't receive packets they send. It
283 * is now necessary to clear "useloopback" and
284 * remove the route to force traffic out to
288 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)),
289 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen);
298 LIST_REMOVE(la, la_le);
299 rt->rt_llinfo = NULL;
300 rt->rt_flags &= ~RTF_LLINFO;
301 if (la->la_hold != NULL)
302 m_freem(la->la_hold);
308 * Broadcast an ARP request. Caller specifies:
309 * - arp header source ip address
310 * - arp header target ip address
311 * - arp header source ethernet address
314 arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip,
318 struct ether_header *eh;
319 struct arc_header *arh;
322 static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP,
323 LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 };
326 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL)
328 m->m_pkthdr.rcvif = (struct ifnet *)NULL;
330 switch (ifp->if_type) {
332 ar_hrd = htons(ARPHRD_ARCNET);
334 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
335 m->m_pkthdr.len = m->m_len;
336 MH_ALIGN(m, m->m_len);
338 arh = (struct arc_header *)sa.sa_data;
339 arh->arc_dhost = ifp->if_broadcastaddr[0];
340 arh->arc_type = ARCTYPE_ARP;
342 ah = mtod(m, struct arphdr *);
346 ar_hrd = htons(ARPHRD_IEEE802);
348 m->m_len = (sizeof llcx) +
349 arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
350 m->m_pkthdr.len = m->m_len;
351 MH_ALIGN(m, m->m_len);
353 memcpy(mtod(m, caddr_t), llcx, sizeof llcx);
354 memcpy(sa.sa_data, ifp->if_broadcastaddr, ifp->if_addrlen);
355 memcpy(sa.sa_data + 6, enaddr, 6);
356 sa.sa_data[6] |= TR_RII;
357 sa.sa_data[12] = TR_AC;
358 sa.sa_data[13] = TR_LLC_FRAME;
360 ah = (struct arphdr *)(mtod(m, char *) + sizeof llcx);
365 * This may not be correct for types not explicitly
366 * listed, but this is our best guess
369 ar_hrd = htons(ARPHRD_ETHER);
371 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
372 m->m_pkthdr.len = m->m_len;
373 MH_ALIGN(m, m->m_len);
375 eh = (struct ether_header *)sa.sa_data;
376 /* if_output() will not swap */
377 eh->ether_type = htons(ETHERTYPE_ARP);
378 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen);
380 ah = mtod(m, struct arphdr *);
385 ah->ar_pro = htons(ETHERTYPE_IP);
386 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
387 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
388 ah->ar_op = htons(ARPOP_REQUEST);
389 memcpy(ar_sha(ah), enaddr, ah->ar_hln);
390 memset(ar_tha(ah), 0, ah->ar_hln);
391 memcpy(ar_spa(ah), sip, ah->ar_pln);
392 memcpy(ar_tpa(ah), tip, ah->ar_pln);
394 sa.sa_family = AF_UNSPEC;
395 sa.sa_len = sizeof sa;
396 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)NULL);
400 * Resolve an IP address into an ethernet address. If success,
401 * desten is filled in. If there is no entry in arptab,
402 * set one up and broadcast a request for the IP address.
403 * Hold onto this mbuf and resend it once the address
404 * is finally resolved. A return value of 1 indicates
405 * that desten has been filled in and the packet should be sent
406 * normally; a 0 return indicates that the packet has been
407 * taken over here, either now or for later transmission.
414 struct sockaddr *dst,
418 struct llinfo_arp *la = NULL;
419 struct sockaddr_dl *sdl;
421 if (m->m_flags & M_BCAST) { /* broadcast */
422 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
425 if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */
426 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
430 if (rt_llroute(dst, rt0, &rt) != 0) {
437 la = arplookup(SIN(dst)->sin_addr.s_addr, TRUE, FALSE);
441 if (la == NULL || rt == NULL) {
442 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n",
443 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ",
448 sdl = SDL(rt->rt_gateway);
450 * Check the address family and length is valid, the address
451 * is resolved; otherwise, try to resolve.
453 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) &&
454 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
456 * If entry has an expiry time and it is approaching,
457 * see if we need to send an ARP request within this
458 * arpt_down interval.
460 if ((rt->rt_expire != 0) &&
461 (time_second + la->la_preempt > rt->rt_expire)) {
463 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
469 bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
473 * If ARP is disabled on this interface, stop.
475 * Probably should not allocate empty llinfo struct if we are
476 * not going to be sending out an arp request.
478 if (ifp->if_flags & IFF_NOARP) {
483 * There is an arptab entry, but no ethernet address
484 * response yet. Replace the held mbuf with this
487 if (la->la_hold != NULL)
488 m_freem(la->la_hold);
490 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) {
491 rt->rt_flags &= ~RTF_REJECT;
492 if (la->la_asked == 0 || rt->rt_expire != time_second) {
493 rt->rt_expire = time_second;
494 if (la->la_asked++ < arp_maxtries) {
496 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
500 rt->rt_flags |= RTF_REJECT;
501 rt->rt_expire += arpt_down;
503 la->la_preempt = arp_maxtries;
512 * Common length and type checks are done here,
513 * then the protocol-specific routine is called.
516 arpintr(struct netmsg *msg)
518 struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
522 if (m->m_len < sizeof(struct arphdr) &&
523 ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) {
524 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
527 ar = mtod(m, struct arphdr *);
529 ar_hrd = ntohs(ar->ar_hrd);
530 if (ar_hrd != ARPHRD_ETHER &&
531 ar_hrd != ARPHRD_IEEE802 &&
532 ar_hrd != ARPHRD_ARCNET) {
534 "arp: unknown hardware address format (0x%2D)\n",
535 (unsigned char *)&ar->ar_hrd, "");
539 if (m->m_pkthdr.len < arphdr_len(ar) &&
540 (m = m_pullup(m, arphdr_len(ar))) == NULL) {
541 log(LOG_ERR, "arp: runt packet\n");
545 switch (ntohs(ar->ar_pro)) {
555 /* msg was embedded in the mbuf, do not reply! */
561 * ARP for Internet protocols on 10 Mb/s Ethernet.
562 * Algorithm is that given in RFC 826.
563 * In addition, a sanity check is performed on the sender
564 * protocol address, to catch impersonators.
565 * We no longer handle negotiations for use of trailer protocol:
566 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
567 * along with IP replies if we wanted trailers sent to us,
568 * and also sent them in response to IP replies.
569 * This allowed either end to announce the desire to receive
571 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
572 * but formerly didn't normally send requests.
574 static int log_arp_wrong_iface = 1;
575 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
576 &log_arp_wrong_iface, 0,
577 "log arp packets arriving on the wrong interface");
580 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create,
583 struct arphdr *ah = mtod(m, struct arphdr *);
584 struct ifnet *ifp = m->m_pkthdr.rcvif;
585 struct llinfo_arp *la;
586 struct sockaddr_dl *sdl;
590 la = arplookup(saddr, create, FALSE);
591 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
592 struct in_addr isaddr = { saddr };
594 /* the following is not an error when doing bridging */
595 if (rt->rt_ifp != ifp) {
596 if (dologging && log_arp_wrong_iface && cpu == 0) {
599 "but got reply from %*D on %s\n",
601 rt->rt_ifp->if_xname,
602 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
608 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
609 if (rt->rt_expire != 0) {
610 if (dologging && cpu == 0) {
612 "arp: %s moved from %*D to %*D on %s\n",
614 ifp->if_addrlen, (u_char *)LLADDR(sdl),
615 ":", ifp->if_addrlen,
616 (u_char *)ar_sha(ah), ":",
620 if (dologging && cpu == 0) {
622 "arp: %*D attempts to modify permanent entry for %s on %s\n",
623 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
624 inet_ntoa(isaddr), ifp->if_xname);
630 * sanity check for the address length.
631 * XXX this does not work for protocols with variable address
634 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln &&
638 "arp from %*D: new addr len %d, was %d",
639 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
640 ah->ar_hln, sdl->sdl_alen);
642 if (ifp->if_addrlen != ah->ar_hln) {
643 if (dologging && cpu == 0) {
645 "arp from %*D: addr len: new %d, i/f %d (ignored)",
646 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
647 ah->ar_hln, ifp->if_addrlen);
651 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln);
653 * If we receive an arp from a token-ring station over
654 * a token-ring nic then try to save the source
657 if (ifp->if_type == IFT_ISO88025) {
658 struct iso88025_header *th =
659 (struct iso88025_header *)m->m_pkthdr.header;
660 struct iso88025_sockaddr_dl_data *trld =
664 rif_len = TR_RCF_RIFLEN(th->rcf);
665 if ((th->iso88025_shost[0] & TR_RII) &&
667 trld->trld_rcf = th->rcf;
668 trld->trld_rcf ^= htons(TR_RCF_DIR);
669 memcpy(trld->trld_route, th->rd, rif_len - 2);
670 trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK);
672 * Set up source routing information for
675 m->m_data -= rif_len;
677 m->m_pkthdr.len += rif_len;
679 th->iso88025_shost[0] &= ~TR_RII;
684 m->m_pkthdr.len += 8;
685 th->rcf = trld->trld_rcf;
687 if (rt->rt_expire != 0)
688 rt->rt_expire = time_second + arpt_keep;
689 rt->rt_flags &= ~RTF_REJECT;
691 la->la_preempt = arp_maxtries;
694 * This particular cpu might have been holding an mbuf
695 * pending ARP resolution. If so, transmit the mbuf now.
697 if (la->la_hold != NULL) {
698 m_adj(la->la_hold, sizeof(struct ether_header));
699 lwkt_serialize_enter(ifp->if_serializer);
700 (*ifp->if_output)(ifp, la->la_hold, rt_key(rt), rt);
701 lwkt_serialize_exit(ifp->if_serializer);
709 struct netmsg_arp_update {
710 struct lwkt_msg lmsg;
716 static int arp_update_msghandler(struct lwkt_msg *lmsg);
721 * Called from arpintr() - this routine is run from a single cpu.
724 in_arpinput(struct mbuf *m)
727 struct ifnet *ifp = m->m_pkthdr.rcvif;
728 struct ether_header *eh;
729 struct arc_header *arh;
730 struct iso88025_header *th = (struct iso88025_header *)NULL;
733 struct in_ifaddr *ia;
735 struct in_addr isaddr, itaddr, myaddr;
737 struct netmsg_arp_update msg;
742 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
743 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
744 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
748 ah = mtod(m, struct arphdr *);
749 op = ntohs(ah->ar_op);
750 memcpy(&isaddr, ar_spa(ah), sizeof isaddr);
751 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr);
753 * Check both target and sender IP addresses:
755 * If we receive the packet on the interface owning the address,
756 * then accept the address.
758 * For a bridge, we accept the address if the receive interface and
759 * the interface owning the address are on the same bridge.
760 * (This will change slightly when we have clusters of interfaces).
762 LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) {
763 /* Skip all ia's which don't match */
764 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
767 if (ia->ia_ifp == ifp)
770 if (ifp->if_bridge && ia->ia_ifp &&
771 ifp->if_bridge == ia->ia_ifp->if_bridge)
774 LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) {
775 /* Skip all ia's which don't match */
776 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
779 if (ia->ia_ifp == ifp)
782 if (ifp->if_bridge && ia->ia_ifp &&
783 ifp->if_bridge == ia->ia_ifp->if_bridge)
787 * No match, use the first inet address on the receive interface
788 * as a dummy address for the rest of the function.
790 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
791 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
797 * If we got here, we didn't find any suitable interface,
798 * so drop the packet.
804 myaddr = ia->ia_addr.sin_addr;
805 if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) {
806 m_freem(m); /* it's from me, ignore it. */
809 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
811 "arp: link address is broadcast for IP address %s!\n",
816 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
818 "arp: %*D is using my IP address %s!\n",
819 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
825 lwkt_initmsg(&msg.lmsg, &curthread->td_msgport, 0,
826 lwkt_cmd_func(arp_update_msghandler), lwkt_cmd_op_none);
828 msg.saddr = isaddr.s_addr;
829 msg.create = (itaddr.s_addr == myaddr.s_addr);
830 lwkt_domsg(rtable_portfn(0), &msg.lmsg);
832 arp_update_oncpu(m, isaddr.s_addr, (itaddr.s_addr == myaddr.s_addr),
835 if (op != ARPOP_REQUEST) {
839 if (itaddr.s_addr == myaddr.s_addr) {
840 /* I am the target */
841 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
842 memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
844 struct llinfo_arp *la;
846 la = arplookup(itaddr.s_addr, FALSE, SIN_PROXY);
848 struct sockaddr_in sin;
855 bzero(&sin, sizeof sin);
856 sin.sin_family = AF_INET;
857 sin.sin_len = sizeof sin;
858 sin.sin_addr = itaddr;
860 rt = rtpurelookup((struct sockaddr *)&sin);
867 * Don't send proxies for nodes on the same interface
868 * as this one came out of, or we'll get into a fight
869 * over who claims what Ether address.
871 if (rt->rt_ifp == ifp) {
875 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
876 memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln);
878 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr));
881 struct sockaddr_dl *sdl;
884 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
885 sdl = SDL(rt->rt_gateway);
886 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
890 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
891 memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
892 ah->ar_op = htons(ARPOP_REPLY);
893 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
894 switch (ifp->if_type) {
896 arh = (struct arc_header *)sa.sa_data;
897 arh->arc_dhost = *ar_tha(ah);
898 arh->arc_type = ARCTYPE_ARP;
901 /* Re-arrange the source/dest address */
902 memcpy(th->iso88025_dhost, th->iso88025_shost,
903 sizeof th->iso88025_dhost);
904 memcpy(th->iso88025_shost, IF_LLADDR(ifp),
905 sizeof th->iso88025_shost);
906 /* Set the source routing bit if neccesary */
907 if (th->iso88025_dhost[0] & TR_RII) {
908 th->iso88025_dhost[0] &= ~TR_RII;
909 if (TR_RCF_RIFLEN(th->rcf) > 2)
910 th->iso88025_shost[0] |= TR_RII;
912 /* Copy the addresses, ac and fc into sa_data */
913 memcpy(sa.sa_data, th->iso88025_dhost,
914 (sizeof th->iso88025_dhost) * 2);
915 sa.sa_data[(sizeof th->iso88025_dhost) * 2] = TR_AC;
916 sa.sa_data[(sizeof th->iso88025_dhost) * 2 + 1] = TR_LLC_FRAME;
921 * May not be correct for types not explictly
922 * listed, but it is our best guess.
925 eh = (struct ether_header *)sa.sa_data;
926 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost);
927 eh->ether_type = htons(ETHERTYPE_ARP);
930 sa.sa_family = AF_UNSPEC;
931 sa.sa_len = sizeof sa;
932 lwkt_serialize_enter(ifp->if_serializer);
933 (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0);
934 lwkt_serialize_exit(ifp->if_serializer);
942 arp_update_msghandler(struct lwkt_msg *lmsg)
944 struct netmsg_arp_update *msg = (struct netmsg_arp_update *)lmsg;
947 arp_update_oncpu(msg->m, msg->saddr, msg->create, FALSE);
949 nextcpu = mycpuid + 1;
950 if (nextcpu < ncpus) {
951 lwkt_forwardmsg(rtable_portfn(nextcpu), &msg->lmsg);
953 lwkt_replymsg(&msg->lmsg, 0);
963 * Free an arp entry. If the arp entry is actively referenced or represents
964 * a static entry we only clear it back to an unresolved state, otherwise
965 * we destroy the entry entirely.
967 * Note that static entries are created when route add ... -interface is used
968 * to create an interface route to a (direct) destination.
971 arptfree(struct llinfo_arp *la)
973 struct rtentry *rt = la->la_rt;
974 struct sockaddr_dl *sdl;
978 sdl = SDL(rt->rt_gateway);
980 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) ||
981 (rt->rt_flags & RTF_STATIC))) {
983 la->la_preempt = la->la_asked = 0;
984 rt->rt_flags &= ~RTF_REJECT;
987 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL);
991 * Lookup or enter a new address in arptab.
993 static struct llinfo_arp *
994 arplookup(in_addr_t addr, boolean_t create, boolean_t proxy)
997 struct sockaddr_inarp sin = { sizeof sin, AF_INET };
998 const char *why = NULL;
1000 sin.sin_addr.s_addr = addr;
1001 sin.sin_other = proxy ? SIN_PROXY : 0;
1003 rt = rtlookup((struct sockaddr *)&sin);
1005 rt = rtpurelookup((struct sockaddr *)&sin);
1010 if (rt->rt_flags & RTF_GATEWAY)
1011 why = "host is not on local network";
1012 else if (!(rt->rt_flags & RTF_LLINFO))
1013 why = "could not allocate llinfo";
1014 else if (rt->rt_gateway->sa_family != AF_LINK)
1015 why = "gateway route is not ours";
1019 log(LOG_DEBUG, "arplookup %s failed: %s\n",
1020 inet_ntoa(sin.sin_addr), why);
1022 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) {
1023 /* No references to this route. Purge it. */
1024 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
1025 rt_mask(rt), rt->rt_flags, NULL);
1029 return (rt->rt_llinfo);
1033 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
1035 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY)
1036 arprequest(ifp, &IA_SIN(ifa)->sin_addr, &IA_SIN(ifa)->sin_addr,
1038 ifa->ifa_rtrequest = arp_rtrequest;
1039 ifa->ifa_flags |= RTF_CLONING;
1047 for (cpu = 0; cpu < ncpus2; cpu++)
1048 LIST_INIT(&llinfo_arp_list[cpu]);
1049 netisr_register(NETISR_ARP, cpu0_portfn, arpintr);
1052 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);