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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 1.59 2008/11/22 11:03:35 sephe Exp $
71 * Ethernet address resolution protocol.
73 * add "inuse/lock" bit (or ref. count) along with valid bit
79 #include <sys/param.h>
80 #include <sys/kernel.h>
81 #include <sys/queue.h>
82 #include <sys/sysctl.h>
83 #include <sys/systm.h>
85 #include <sys/malloc.h>
86 #include <sys/socket.h>
87 #include <sys/syslog.h>
91 #include <net/if_dl.h>
92 #include <net/if_types.h>
93 #include <net/route.h>
94 #include <net/netisr.h>
95 #include <net/if_llc.h>
97 #include <netinet/in.h>
98 #include <netinet/in_var.h>
99 #include <netinet/if_ether.h>
101 #include <sys/thread2.h>
102 #include <sys/msgport2.h>
103 #include <net/netmsg2.h>
104 #include <sys/mplock2.h>
107 #include <netinet/ip_carp.h>
110 #define SIN(s) ((struct sockaddr_in *)s)
111 #define SDL(s) ((struct sockaddr_dl *)s)
113 SYSCTL_DECL(_net_link_ether);
114 SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, "");
117 static int arpt_prune = (5*60*1); /* walk list every 5 minutes */
118 static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
119 static int arpt_down = 20; /* once declared down, don't send for 20 sec */
121 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW,
123 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW,
125 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW,
128 #define rt_expire rt_rmx.rmx_expire
131 LIST_ENTRY(llinfo_arp) la_le;
132 struct rtentry *la_rt;
133 struct mbuf *la_hold; /* last packet until resolved/timeout */
134 struct lwkt_port *la_msgport; /* last packet's msgport */
135 u_short la_preempt; /* countdown for pre-expiry arps */
136 u_short la_asked; /* #times we QUERIED following expiration */
139 static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU];
141 static int arp_maxtries = 5;
142 static int useloopback = 1; /* use loopback interface for local traffic */
143 static int arp_proxyall = 0;
145 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW,
146 &arp_maxtries, 0, "ARP resolution attempts before returning error");
147 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW,
148 &useloopback, 0, "Use the loopback interface for local traffic");
149 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW,
150 &arp_proxyall, 0, "Enable proxy ARP for all suitable requests");
152 static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
153 static void arprequest(struct ifnet *, const struct in_addr *,
154 const struct in_addr *, const u_char *);
155 static void arprequest_async(struct ifnet *, const struct in_addr *,
156 const struct in_addr *, const u_char *);
157 static void arpintr(netmsg_t msg);
158 static void arptfree(struct llinfo_arp *);
159 static void arptimer(void *);
160 static struct llinfo_arp *
161 arplookup(in_addr_t, boolean_t, boolean_t, boolean_t);
163 static void in_arpinput(struct mbuf *);
166 static struct callout arptimer_ch[MAXCPU];
169 * Timeout routine. Age arp_tab entries periodically.
173 arptimer(void *ignored_arg)
175 struct llinfo_arp *la, *nla;
178 LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) {
179 if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second)
182 callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL);
187 * Parallel to llc_rtrequest.
190 arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
192 struct sockaddr *gate = rt->rt_gateway;
193 struct llinfo_arp *la = rt->rt_llinfo;
195 struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK };
196 static boolean_t arpinit_done[MAXCPU];
198 if (!arpinit_done[mycpuid]) {
199 arpinit_done[mycpuid] = TRUE;
200 callout_init(&arptimer_ch[mycpuid]);
201 callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL);
203 if (rt->rt_flags & RTF_GATEWAY)
209 * XXX: If this is a manually added route to interface
210 * such as older version of routed or gated might provide,
211 * restore cloning bit.
213 if (!(rt->rt_flags & RTF_HOST) &&
214 SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
215 rt->rt_flags |= RTF_CLONING;
216 if (rt->rt_flags & RTF_CLONING) {
218 * Case 1: This route should come from a route to iface.
220 rt_setgate(rt, rt_key(rt),
221 (struct sockaddr *)&null_sdl,
223 gate = rt->rt_gateway;
224 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
225 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
226 rt->rt_expire = time_second;
229 /* Announce a new entry if requested. */
230 if (rt->rt_flags & RTF_ANNOUNCE) {
231 arprequest_async(rt->rt_ifp,
232 &SIN(rt_key(rt))->sin_addr,
233 &SIN(rt_key(rt))->sin_addr,
238 if (gate->sa_family != AF_LINK ||
239 gate->sa_len < sizeof(struct sockaddr_dl)) {
240 log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n");
243 SDL(gate)->sdl_type = rt->rt_ifp->if_type;
244 SDL(gate)->sdl_index = rt->rt_ifp->if_index;
246 break; /* This happens on a route change */
248 * Case 2: This route may come from cloning, or a manual route
249 * add with a LL address.
251 R_Malloc(la, struct llinfo_arp *, sizeof *la);
254 log(LOG_DEBUG, "arp_rtrequest: malloc failed\n");
257 bzero(la, sizeof *la);
259 rt->rt_flags |= RTF_LLINFO;
260 LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le);
264 * This keeps the multicast addresses from showing up
265 * in `arp -a' listings as unresolved. It's not actually
266 * functional. Then the same for broadcast.
268 if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) {
269 ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr,
271 SDL(gate)->sdl_alen = 6;
274 if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) {
275 memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr,
276 rt->rt_ifp->if_addrlen);
277 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen;
282 if (SIN(rt_key(rt))->sin_addr.s_addr ==
283 (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) {
285 * This test used to be
286 * if (loif.if_flags & IFF_UP)
287 * It allowed local traffic to be forced
288 * through the hardware by configuring the
289 * loopback down. However, it causes problems
290 * during network configuration for boards
291 * that can't receive packets they send. It
292 * is now necessary to clear "useloopback" and
293 * remove the route to force traffic out to
297 bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)),
298 SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen);
307 LIST_REMOVE(la, la_le);
308 rt->rt_llinfo = NULL;
309 rt->rt_flags &= ~RTF_LLINFO;
310 if (la->la_hold != NULL)
311 m_freem(la->la_hold);
318 arpreq_alloc(struct ifnet *ifp, const struct in_addr *sip,
319 const struct in_addr *tip, const u_char *enaddr)
325 if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL)
327 m->m_pkthdr.rcvif = NULL;
329 switch (ifp->if_type) {
332 * This may not be correct for types not explicitly
333 * listed, but this is our best guess
336 ar_hrd = htons(ARPHRD_ETHER);
338 m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
339 m->m_pkthdr.len = m->m_len;
340 MH_ALIGN(m, m->m_len);
342 ah = mtod(m, struct arphdr *);
347 ah->ar_pro = htons(ETHERTYPE_IP);
348 ah->ar_hln = ifp->if_addrlen; /* hardware address length */
349 ah->ar_pln = sizeof(struct in_addr); /* protocol address length */
350 ah->ar_op = htons(ARPOP_REQUEST);
351 memcpy(ar_sha(ah), enaddr, ah->ar_hln);
352 memset(ar_tha(ah), 0, ah->ar_hln);
353 memcpy(ar_spa(ah), sip, ah->ar_pln);
354 memcpy(ar_tpa(ah), tip, ah->ar_pln);
360 arpreq_send(struct ifnet *ifp, struct mbuf *m)
363 struct ether_header *eh;
365 switch (ifp->if_type) {
368 * This may not be correct for types not explicitly
369 * listed, but this is our best guess
372 eh = (struct ether_header *)sa.sa_data;
373 /* if_output() will not swap */
374 eh->ether_type = htons(ETHERTYPE_ARP);
375 memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen);
379 sa.sa_family = AF_UNSPEC;
380 sa.sa_len = sizeof(sa);
381 ifp->if_output(ifp, m, &sa, NULL);
385 arpreq_send_handler(netmsg_t msg)
387 struct mbuf *m = msg->packet.nm_packet;
388 struct ifnet *ifp = msg->lmsg.u.ms_resultp;
391 /* nmsg was embedded in the mbuf, do not reply! */
395 * Broadcast an ARP request. Caller specifies:
396 * - arp header source ip address
397 * - arp header target ip address
398 * - arp header source ethernet address
400 * NOTE: Caller MUST NOT hold ifp's serializer
403 arprequest(struct ifnet *ifp, const struct in_addr *sip,
404 const struct in_addr *tip, const u_char *enaddr)
408 m = arpreq_alloc(ifp, sip, tip, enaddr);
415 * Same as arprequest(), except:
416 * - Caller is allowed to hold ifp's serializer
417 * - Network output is done in protocol thead
420 arprequest_async(struct ifnet *ifp, const struct in_addr *sip,
421 const struct in_addr *tip, const u_char *enaddr)
424 struct netmsg_packet *pmsg;
426 m = arpreq_alloc(ifp, sip, tip, enaddr);
430 pmsg = &m->m_hdr.mh_netmsg;
431 netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
432 0, arpreq_send_handler);
434 pmsg->base.lmsg.u.ms_resultp = ifp;
436 lwkt_sendmsg(cpu_portfn(mycpuid), &pmsg->base.lmsg);
440 * Resolve an IP address into an ethernet address. If success,
441 * desten is filled in. If there is no entry in arptab,
442 * set one up and broadcast a request for the IP address.
443 * Hold onto this mbuf and resend it once the address
444 * is finally resolved. A return value of 1 indicates
445 * that desten has been filled in and the packet should be sent
446 * normally; a 0 return indicates that the packet has been
447 * taken over here, either now or for later transmission.
450 arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m,
451 struct sockaddr *dst, u_char *desten)
454 struct llinfo_arp *la = NULL;
455 struct sockaddr_dl *sdl;
457 if (m->m_flags & M_BCAST) { /* broadcast */
458 memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen);
461 if (m->m_flags & M_MCAST) {/* multicast */
462 ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten);
466 if (rt_llroute(dst, rt0, &rt) != 0) {
473 la = arplookup(SIN(dst)->sin_addr.s_addr,
474 TRUE, RTL_REPORTMSG, FALSE);
478 if (la == NULL || rt == NULL) {
479 log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n",
480 inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ",
485 sdl = SDL(rt->rt_gateway);
487 * Check the address family and length is valid, the address
488 * is resolved; otherwise, try to resolve.
490 if ((rt->rt_expire == 0 || rt->rt_expire > time_second) &&
491 sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
493 * If entry has an expiry time and it is approaching,
494 * see if we need to send an ARP request within this
495 * arpt_down interval.
497 if ((rt->rt_expire != 0) &&
498 (time_second + la->la_preempt > rt->rt_expire)) {
500 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
506 bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
510 * If ARP is disabled or static on this interface, stop.
512 * Probably should not allocate empty llinfo struct if we are
513 * not going to be sending out an arp request.
515 if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) {
520 * There is an arptab entry, but no ethernet address
521 * response yet. Replace the held mbuf with this
524 if (la->la_hold != NULL)
525 m_freem(la->la_hold);
527 la->la_msgport = cur_netport();
528 if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) {
529 rt->rt_flags &= ~RTF_REJECT;
530 if (la->la_asked == 0 || rt->rt_expire != time_second) {
531 rt->rt_expire = time_second;
532 if (la->la_asked++ < arp_maxtries) {
534 &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
538 rt->rt_flags |= RTF_REJECT;
539 rt->rt_expire += arpt_down;
541 la->la_preempt = arp_maxtries;
549 * Common length and type checks are done here,
550 * then the protocol-specific routine is called.
553 arpintr(netmsg_t msg)
555 struct mbuf *m = msg->packet.nm_packet;
559 if (m->m_len < sizeof(struct arphdr) &&
560 (m = m_pullup(m, sizeof(struct arphdr))) == NULL) {
561 log(LOG_ERR, "arp: runt packet -- m_pullup failed\n");
564 ar = mtod(m, struct arphdr *);
566 ar_hrd = ntohs(ar->ar_hrd);
567 if (ar_hrd != ARPHRD_ETHER && ar_hrd != ARPHRD_IEEE802) {
568 log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n",
569 (unsigned char *)&ar->ar_hrd, "");
574 if (m->m_pkthdr.len < arphdr_len(ar)) {
575 if ((m = m_pullup(m, arphdr_len(ar))) == NULL) {
576 log(LOG_ERR, "arp: runt packet\n");
579 ar = mtod(m, struct arphdr *);
582 switch (ntohs(ar->ar_pro)) {
590 /* msg was embedded in the mbuf, do not reply! */
595 * ARP for Internet protocols on 10 Mb/s Ethernet.
596 * Algorithm is that given in RFC 826.
597 * In addition, a sanity check is performed on the sender
598 * protocol address, to catch impersonators.
599 * We no longer handle negotiations for use of trailer protocol:
600 * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent
601 * along with IP replies if we wanted trailers sent to us,
602 * and also sent them in response to IP replies.
603 * This allowed either end to announce the desire to receive
605 * We no longer reply to requests for ETHERTYPE_TRAIL protocol either,
606 * but formerly didn't normally send requests.
609 static int log_arp_wrong_iface = 1;
610 static int log_arp_movements = 1;
611 static int log_arp_permanent_modify = 1;
613 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW,
614 &log_arp_wrong_iface, 0,
615 "Log arp packets arriving on the wrong interface");
616 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW,
617 &log_arp_movements, 0,
618 "Log arp replies from MACs different than the one in the cache");
619 SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW,
620 &log_arp_permanent_modify, 0,
621 "Log arp replies from MACs different than the one "
622 "in the permanent arp entry");
626 arp_hold_output(netmsg_t msg)
628 struct mbuf *m = msg->packet.nm_packet;
632 rt = msg->lmsg.u.ms_resultp;
633 ifp = m->m_pkthdr.rcvif;
634 m->m_pkthdr.rcvif = NULL;
636 ifp->if_output(ifp, m, rt_key(rt), rt);
638 /* Drop the reference count bumped by the sender */
641 /* nmsg was embedded in the mbuf, do not reply! */
645 arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create,
646 boolean_t generate_report, boolean_t dologging)
648 struct arphdr *ah = mtod(m, struct arphdr *);
649 struct ifnet *ifp = m->m_pkthdr.rcvif;
650 struct llinfo_arp *la;
651 struct sockaddr_dl *sdl;
654 la = arplookup(saddr, create, generate_report, FALSE);
655 if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) {
656 struct in_addr isaddr = { saddr };
658 /* the following is not an error when doing bridging */
659 if (rt->rt_ifp != ifp) {
660 if (dologging && log_arp_wrong_iface) {
663 "but got reply from %*D on %s\n",
665 rt->rt_ifp->if_xname,
666 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
672 bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) {
673 if (rt->rt_expire != 0) {
674 if (dologging && log_arp_movements) {
676 "arp: %s moved from %*D to %*D on %s\n",
678 ifp->if_addrlen, (u_char *)LLADDR(sdl),
679 ":", ifp->if_addrlen,
680 (u_char *)ar_sha(ah), ":",
684 if (dologging && log_arp_permanent_modify) {
686 "arp: %*D attempts to modify "
687 "permanent entry for %s on %s\n",
688 ifp->if_addrlen, (u_char *)ar_sha(ah),
689 ":", inet_ntoa(isaddr), ifp->if_xname);
695 * sanity check for the address length.
696 * XXX this does not work for protocols with variable address
699 if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln) {
701 "arp from %*D: new addr len %d, was %d",
702 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
703 ah->ar_hln, sdl->sdl_alen);
705 if (ifp->if_addrlen != ah->ar_hln) {
708 "arp from %*D: addr len: new %d, i/f %d "
710 ifp->if_addrlen, (u_char *) ar_sha(ah), ":",
711 ah->ar_hln, ifp->if_addrlen);
715 memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln);
716 if (rt->rt_expire != 0)
717 rt->rt_expire = time_second + arpt_keep;
718 rt->rt_flags &= ~RTF_REJECT;
720 la->la_preempt = arp_maxtries;
723 * This particular cpu might have been holding an mbuf
724 * pending ARP resolution. If so, transmit the mbuf now.
726 if (la->la_hold != NULL) {
727 struct mbuf *m = la->la_hold;
728 struct lwkt_port *port = la->la_msgport;
729 struct netmsg_packet *pmsg;
732 la->la_msgport = NULL;
734 m_adj(m, sizeof(struct ether_header));
737 * Make sure that this rtentry will not be freed
738 * before the packet is processed on the target
739 * msgport. The reference count will be dropped
740 * in the handler associated with this packet.
744 pmsg = &m->m_hdr.mh_netmsg;
745 netmsg_init(&pmsg->base, NULL,
746 &netisr_apanic_rport,
747 MSGF_PRIORITY, arp_hold_output);
750 /* Record necessary information */
751 m->m_pkthdr.rcvif = ifp;
752 pmsg->base.lmsg.u.ms_resultp = rt;
754 lwkt_sendmsg(port, &pmsg->base.lmsg);
761 struct netmsg_arp_update {
762 struct netmsg_base base;
768 static void arp_update_msghandler(netmsg_t msg);
773 * Called from arpintr() - this routine is run from a single cpu.
776 in_arpinput(struct mbuf *m)
779 struct ifnet *ifp = m->m_pkthdr.rcvif;
780 struct ether_header *eh;
782 struct ifaddr_container *ifac;
783 struct in_ifaddr_container *iac;
784 struct in_ifaddr *ia = NULL;
786 struct in_addr isaddr, itaddr, myaddr;
788 struct netmsg_arp_update msg;
790 uint8_t *enaddr = NULL;
794 req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr));
795 if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) {
796 log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n");
800 ah = mtod(m, struct arphdr *);
801 op = ntohs(ah->ar_op);
802 memcpy(&isaddr, ar_spa(ah), sizeof isaddr);
803 memcpy(&itaddr, ar_tpa(ah), sizeof itaddr);
805 myaddr.s_addr = INADDR_ANY;
807 if (ifp->if_carp != NULL) {
809 if (ifp->if_carp != NULL &&
810 carp_iamatch(ifp->if_carp, &itaddr, &isaddr, &enaddr)) {
820 * Check both target and sender IP addresses:
822 * If we receive the packet on the interface owning the address,
823 * then accept the address.
825 * For a bridge, we accept the address if the receive interface and
826 * the interface owning the address are on the same bridge.
827 * (This will change slightly when we have clusters of interfaces).
829 LIST_FOREACH(iac, INADDR_HASH(itaddr.s_addr), ia_hash) {
832 /* Skip all ia's which don't match */
833 if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
836 if (ia->ia_ifp->if_type == IFT_CARP)
839 if (ia->ia_ifp == ifp)
842 if (ifp->if_bridge && ia->ia_ifp &&
843 ifp->if_bridge == ia->ia_ifp->if_bridge)
846 LIST_FOREACH(iac, INADDR_HASH(isaddr.s_addr), ia_hash) {
849 /* Skip all ia's which don't match */
850 if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr)
853 if (ia->ia_ifp->if_type == IFT_CARP)
856 if (ia->ia_ifp == ifp)
859 if (ifp->if_bridge && ia->ia_ifp &&
860 ifp->if_bridge == ia->ia_ifp->if_bridge)
864 * No match, use the first inet address on the receive interface
865 * as a dummy address for the rest of the function.
867 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
868 struct ifaddr *ifa = ifac->ifa;
870 if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) {
876 * If we got here, we didn't find any suitable interface,
877 * so drop the packet.
884 enaddr = (uint8_t *)IF_LLADDR(ifp);
885 if (myaddr.s_addr == INADDR_ANY)
886 myaddr = ia->ia_addr.sin_addr;
887 if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) {
888 m_freem(m); /* it's from me, ignore it. */
891 if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) {
893 "arp: link address is broadcast for IP address %s!\n",
898 if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) {
900 "arp: %*D is using my IP address %s!\n",
901 ifp->if_addrlen, (u_char *)ar_sha(ah), ":",
906 if (ifp->if_flags & IFF_STATICARP)
909 netmsg_init(&msg.base, NULL, &curthread->td_msgport,
910 0, arp_update_msghandler);
912 msg.saddr = isaddr.s_addr;
913 msg.create = (itaddr.s_addr == myaddr.s_addr);
914 lwkt_domsg(rtable_portfn(0), &msg.base.lmsg, 0);
916 arp_update_oncpu(m, isaddr.s_addr, (itaddr.s_addr == myaddr.s_addr),
917 RTL_REPORTMSG, TRUE);
920 if (op != ARPOP_REQUEST) {
924 if (itaddr.s_addr == myaddr.s_addr) {
925 /* I am the target */
926 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
927 memcpy(ar_sha(ah), enaddr, ah->ar_hln);
929 struct llinfo_arp *la;
931 la = arplookup(itaddr.s_addr, FALSE, RTL_DONTREPORT, SIN_PROXY);
933 struct sockaddr_in sin;
940 bzero(&sin, sizeof sin);
941 sin.sin_family = AF_INET;
942 sin.sin_len = sizeof sin;
943 sin.sin_addr = itaddr;
945 rt = rtpurelookup((struct sockaddr *)&sin);
952 * Don't send proxies for nodes on the same interface
953 * as this one came out of, or we'll get into a fight
954 * over who claims what Ether address.
956 if (rt->rt_ifp == ifp) {
960 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
961 memcpy(ar_sha(ah), enaddr, ah->ar_hln);
963 kprintf("arp: proxying for %s\n", inet_ntoa(itaddr));
966 struct sockaddr_dl *sdl;
969 memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln);
970 sdl = SDL(rt->rt_gateway);
971 memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln);
975 memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln);
976 memcpy(ar_spa(ah), &itaddr, ah->ar_pln);
977 ah->ar_op = htons(ARPOP_REPLY);
978 ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */
979 switch (ifp->if_type) {
982 * May not be correct for types not explictly
983 * listed, but it is our best guess.
986 eh = (struct ether_header *)sa.sa_data;
987 memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost);
988 eh->ether_type = htons(ETHERTYPE_ARP);
991 sa.sa_family = AF_UNSPEC;
992 sa.sa_len = sizeof sa;
993 ifp->if_output(ifp, m, &sa, NULL);
999 arp_update_msghandler(netmsg_t msg)
1001 struct netmsg_arp_update *rmsg = (struct netmsg_arp_update *)msg;
1005 * This message handler will be called on all of the CPUs,
1006 * however, we only need to generate rtmsg on CPU0.
1008 arp_update_oncpu(rmsg->m, rmsg->saddr, rmsg->create,
1009 mycpuid == 0 ? RTL_REPORTMSG : RTL_DONTREPORT,
1012 nextcpu = mycpuid + 1;
1013 if (nextcpu < ncpus)
1014 lwkt_forwardmsg(rtable_portfn(nextcpu), &rmsg->base.lmsg);
1016 lwkt_replymsg(&rmsg->base.lmsg, 0);
1024 * Free an arp entry. If the arp entry is actively referenced or represents
1025 * a static entry we only clear it back to an unresolved state, otherwise
1026 * we destroy the entry entirely.
1028 * Note that static entries are created when route add ... -interface is used
1029 * to create an interface route to a (direct) destination.
1032 arptfree(struct llinfo_arp *la)
1034 struct rtentry *rt = la->la_rt;
1035 struct sockaddr_dl *sdl;
1039 sdl = SDL(rt->rt_gateway);
1041 ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) ||
1042 (rt->rt_flags & RTF_STATIC))) {
1044 la->la_preempt = la->la_asked = 0;
1045 rt->rt_flags &= ~RTF_REJECT;
1048 rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL);
1052 * Lookup or enter a new address in arptab.
1054 static struct llinfo_arp *
1055 arplookup(in_addr_t addr, boolean_t create, boolean_t generate_report,
1059 struct sockaddr_inarp sin = { sizeof sin, AF_INET };
1060 const char *why = NULL;
1062 sin.sin_addr.s_addr = addr;
1063 sin.sin_other = proxy ? SIN_PROXY : 0;
1065 rt = _rtlookup((struct sockaddr *)&sin,
1066 generate_report, RTL_DOCLONE);
1068 rt = rtpurelookup((struct sockaddr *)&sin);
1074 if (rt->rt_flags & RTF_GATEWAY)
1075 why = "host is not on local network";
1076 else if (!(rt->rt_flags & RTF_LLINFO))
1077 why = "could not allocate llinfo";
1078 else if (rt->rt_gateway->sa_family != AF_LINK)
1079 why = "gateway route is not ours";
1083 log(LOG_DEBUG, "arplookup %s failed: %s\n",
1084 inet_ntoa(sin.sin_addr), why);
1086 if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) {
1087 /* No references to this route. Purge it. */
1088 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
1089 rt_mask(rt), rt->rt_flags, NULL);
1093 return (rt->rt_llinfo);
1097 arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa)
1099 if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) {
1100 arprequest_async(ifp, &IA_SIN(ifa)->sin_addr,
1101 &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp));
1103 ifa->ifa_rtrequest = arp_rtrequest;
1104 ifa->ifa_flags |= RTF_CLONING;
1108 arp_iainit(struct ifnet *ifp, const struct in_addr *addr, const u_char *enaddr)
1110 if (addr->s_addr != INADDR_ANY)
1111 arprequest_async(ifp, addr, addr, enaddr);
1119 for (cpu = 0; cpu < ncpus2; cpu++)
1120 LIST_INIT(&llinfo_arp_list[cpu]);
1122 netisr_register(NETISR_ARP, arpintr, NULL);
1125 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);