/* * Copyright (c) 2004, 2005 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to The DragonFly Project * by Jeffrey M. Hsu. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of The DragonFly Project nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific, prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 2004, 2005 Jeffrey M. Hsu. All rights reserved. * * License terms: all terms for the DragonFly license above plus the following: * * 4. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * * This product includes software developed by Jeffrey M. Hsu * for the DragonFly Project. * * This requirement may be waived with permission from Jeffrey Hsu. * Permission will be granted to any DragonFly user for free. * This requirement will sunset and may be removed on Jan 31, 2006, * after which the standard DragonFly license (as shown above) will * apply. */ /* * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 * $FreeBSD: src/sys/netinet/if_ether.c,v 1.64.2.23 2003/04/11 07:23:15 fjoe Exp $ * $DragonFly: src/sys/netinet/if_ether.c,v 1.34 2006/07/20 16:22:48 corecode Exp $ */ /* * Ethernet address resolution protocol. * TODO: * add "inuse/lock" bit (or ref. count) along with valid bit */ #include "opt_inet.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SIN(s) ((struct sockaddr_in *)s) #define SDL(s) ((struct sockaddr_dl *)s) SYSCTL_DECL(_net_link_ether); SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); /* timer values */ static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ static int arpt_down = 20; /* once declared down, don't send for 20 sec */ SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, &arpt_prune, 0, ""); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, &arpt_keep, 0, ""); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, &arpt_down, 0, ""); #define rt_expire rt_rmx.rmx_expire struct llinfo_arp { LIST_ENTRY(llinfo_arp) la_le; struct rtentry *la_rt; struct mbuf *la_hold; /* last packet until resolved/timeout */ u_short la_preempt; /* countdown for pre-expiry arps */ u_short la_asked; /* #times we QUERIED following expiration */ }; static LIST_HEAD(, llinfo_arp) llinfo_arp_list[MAXCPU]; static int arp_maxtries = 5; static int useloopback = 1; /* use loopback interface for local traffic */ static int arp_proxyall = 0; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, &arp_maxtries, 0, ""); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, &useloopback, 0, ""); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, &arp_proxyall, 0, ""); static void arp_rtrequest (int, struct rtentry *, struct rt_addrinfo *); static void arprequest (struct ifnet *, struct in_addr *, struct in_addr *, u_char *); static int arpintr(struct netmsg *); static void arptfree (struct llinfo_arp *); static void arptimer (void *); static struct llinfo_arp *arplookup (in_addr_t addr, boolean_t create, boolean_t proxy); #ifdef INET static void in_arpinput (struct mbuf *); #endif static struct callout arptimer_ch[MAXCPU]; /* * Timeout routine. Age arp_tab entries periodically. */ /* ARGSUSED */ static void arptimer(void *ignored_arg) { struct llinfo_arp *la, *nla; crit_enter(); LIST_FOREACH_MUTABLE(la, &llinfo_arp_list[mycpuid], la_le, nla) { if (la->la_rt->rt_expire && la->la_rt->rt_expire <= time_second) arptfree(la); } callout_reset(&arptimer_ch[mycpuid], arpt_prune * hz, arptimer, NULL); crit_exit(); } /* * Parallel to llc_rtrequest. */ static void arp_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info) { struct sockaddr *gate = rt->rt_gateway; struct llinfo_arp *la = rt->rt_llinfo; struct sockaddr_dl null_sdl = { sizeof null_sdl, AF_LINK }; static boolean_t arpinit_done[MAXCPU]; if (!arpinit_done[mycpuid]) { arpinit_done[mycpuid] = TRUE; callout_init(&arptimer_ch[mycpuid]); callout_reset(&arptimer_ch[mycpuid], hz, arptimer, NULL); } if (rt->rt_flags & RTF_GATEWAY) return; switch (req) { case RTM_ADD: /* * XXX: If this is a manually added route to interface * such as older version of routed or gated might provide, * restore cloning bit. */ if (!(rt->rt_flags & RTF_HOST) && SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) rt->rt_flags |= RTF_CLONING; if (rt->rt_flags & RTF_CLONING) { /* * Case 1: This route should come from a route to iface. */ rt_setgate(rt, rt_key(rt), (struct sockaddr *)&null_sdl); gate = rt->rt_gateway; SDL(gate)->sdl_type = rt->rt_ifp->if_type; SDL(gate)->sdl_index = rt->rt_ifp->if_index; rt->rt_expire = time_second; break; } /* Announce a new entry if requested. */ if (rt->rt_flags & RTF_ANNOUNCE) arprequest(rt->rt_ifp, &SIN(rt_key(rt))->sin_addr, &SIN(rt_key(rt))->sin_addr, LLADDR(SDL(gate))); /*FALLTHROUGH*/ case RTM_RESOLVE: if (gate->sa_family != AF_LINK || gate->sa_len < sizeof(struct sockaddr_dl)) { log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); break; } SDL(gate)->sdl_type = rt->rt_ifp->if_type; SDL(gate)->sdl_index = rt->rt_ifp->if_index; if (la != NULL) break; /* This happens on a route change */ /* * Case 2: This route may come from cloning, or a manual route * add with a LL address. */ R_Malloc(la, struct llinfo_arp *, sizeof *la); rt->rt_llinfo = la; if (la == NULL) { log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); break; } bzero(la, sizeof *la); la->la_rt = rt; rt->rt_flags |= RTF_LLINFO; LIST_INSERT_HEAD(&llinfo_arp_list[mycpuid], la, la_le); #ifdef INET /* * This keeps the multicast addresses from showing up * in `arp -a' listings as unresolved. It's not actually * functional. Then the same for broadcast. */ if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) && rt->rt_ifp->if_type != IFT_ARCNET) { ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, LLADDR(SDL(gate))); SDL(gate)->sdl_alen = 6; rt->rt_expire = 0; } if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, rt->rt_ifp->if_addrlen); SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; rt->rt_expire = 0; } #endif if (SIN(rt_key(rt))->sin_addr.s_addr == (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { /* * This test used to be * if (loif.if_flags & IFF_UP) * It allowed local traffic to be forced * through the hardware by configuring the * loopback down. However, it causes problems * during network configuration for boards * that can't receive packets they send. It * is now necessary to clear "useloopback" and * remove the route to force traffic out to * the hardware. */ rt->rt_expire = 0; bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); if (useloopback) rt->rt_ifp = loif; } break; case RTM_DELETE: if (la == NULL) break; LIST_REMOVE(la, la_le); rt->rt_llinfo = NULL; rt->rt_flags &= ~RTF_LLINFO; if (la->la_hold != NULL) m_freem(la->la_hold); Free(la); } } /* * Broadcast an ARP request. Caller specifies: * - arp header source ip address * - arp header target ip address * - arp header source ethernet address */ static void arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip, u_char *enaddr) { struct mbuf *m; struct ether_header *eh; struct arc_header *arh; struct arphdr *ah; struct sockaddr sa; static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP, LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 }; u_short ar_hrd; if ((m = m_gethdr(MB_DONTWAIT, MT_DATA)) == NULL) return; m->m_pkthdr.rcvif = (struct ifnet *)NULL; switch (ifp->if_type) { case IFT_ARCNET: ar_hrd = htons(ARPHRD_ARCNET); m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); m->m_pkthdr.len = m->m_len; MH_ALIGN(m, m->m_len); arh = (struct arc_header *)sa.sa_data; arh->arc_dhost = ifp->if_broadcastaddr[0]; arh->arc_type = ARCTYPE_ARP; ah = mtod(m, struct arphdr *); break; case IFT_ISO88025: ar_hrd = htons(ARPHRD_IEEE802); m->m_len = (sizeof llcx) + arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); m->m_pkthdr.len = m->m_len; MH_ALIGN(m, m->m_len); memcpy(mtod(m, caddr_t), llcx, sizeof llcx); memcpy(sa.sa_data, ifp->if_broadcastaddr, ifp->if_addrlen); memcpy(sa.sa_data + 6, enaddr, 6); sa.sa_data[6] |= TR_RII; sa.sa_data[12] = TR_AC; sa.sa_data[13] = TR_LLC_FRAME; ah = (struct arphdr *)(mtod(m, char *) + sizeof llcx); break; case IFT_FDDI: case IFT_ETHER: /* * This may not be correct for types not explicitly * listed, but this is our best guess */ default: ar_hrd = htons(ARPHRD_ETHER); m->m_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); m->m_pkthdr.len = m->m_len; MH_ALIGN(m, m->m_len); eh = (struct ether_header *)sa.sa_data; /* if_output() will not swap */ eh->ether_type = htons(ETHERTYPE_ARP); memcpy(eh->ether_dhost, ifp->if_broadcastaddr, ifp->if_addrlen); ah = mtod(m, struct arphdr *); break; } ah->ar_hrd = ar_hrd; ah->ar_pro = htons(ETHERTYPE_IP); ah->ar_hln = ifp->if_addrlen; /* hardware address length */ ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ ah->ar_op = htons(ARPOP_REQUEST); memcpy(ar_sha(ah), enaddr, ah->ar_hln); memset(ar_tha(ah), 0, ah->ar_hln); memcpy(ar_spa(ah), sip, ah->ar_pln); memcpy(ar_tpa(ah), tip, ah->ar_pln); sa.sa_family = AF_UNSPEC; sa.sa_len = sizeof sa; (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)NULL); } /* * Resolve an IP address into an ethernet address. If success, * desten is filled in. If there is no entry in arptab, * set one up and broadcast a request for the IP address. * Hold onto this mbuf and resend it once the address * is finally resolved. A return value of 1 indicates * that desten has been filled in and the packet should be sent * normally; a 0 return indicates that the packet has been * taken over here, either now or for later transmission. */ int arpresolve( struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, struct sockaddr *dst, u_char *desten) { struct rtentry *rt; struct llinfo_arp *la = NULL; struct sockaddr_dl *sdl; if (m->m_flags & M_BCAST) { /* broadcast */ memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); return (1); } if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */ ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); return (1); } if (rt0 != NULL) { if (rt_llroute(dst, rt0, &rt) != 0) { m_freem(m); return 0; } la = rt->rt_llinfo; } if (la == NULL) { la = arplookup(SIN(dst)->sin_addr.s_addr, TRUE, FALSE); if (la != NULL) rt = la->la_rt; } if (la == NULL || rt == NULL) { log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", inet_ntoa(SIN(dst)->sin_addr), la ? "la" : " ", rt ? "rt" : ""); m_freem(m); return (0); } sdl = SDL(rt->rt_gateway); /* * Check the address family and length is valid, the address * is resolved; otherwise, try to resolve. */ if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { /* * If entry has an expiry time and it is approaching, * see if we need to send an ARP request within this * arpt_down interval. */ if ((rt->rt_expire != 0) && (time_second + la->la_preempt > rt->rt_expire)) { arprequest(ifp, &SIN(rt->rt_ifa->ifa_addr)->sin_addr, &SIN(dst)->sin_addr, IF_LLADDR(ifp)); la->la_preempt--; } bcopy(LLADDR(sdl), desten, sdl->sdl_alen); return 1; } /* * If ARP is disabled on this interface, stop. * XXX * Probably should not allocate empty llinfo struct if we are * not going to be sending out an arp request. */ if (ifp->if_flags & IFF_NOARP) { m_freem(m); return (0); } /* * There is an arptab entry, but no ethernet address * response yet. Replace the held mbuf with this * latest one. */ if (la->la_hold != NULL) m_freem(la->la_hold); la->la_hold = m; if (rt->rt_expire || ((rt->rt_flags & RTF_STATIC) && !sdl->sdl_alen)) { rt->rt_flags &= ~RTF_REJECT; if (la->la_asked == 0 || rt->rt_expire != time_second) { rt->rt_expire = time_second; if (la->la_asked++ < arp_maxtries) { arprequest(ifp, &SIN(rt->rt_ifa->ifa_addr)->sin_addr, &SIN(dst)->sin_addr, IF_LLADDR(ifp)); } else { rt->rt_flags |= RTF_REJECT; rt->rt_expire += arpt_down; la->la_asked = 0; la->la_preempt = arp_maxtries; } } } return (0); } /* * Common length and type checks are done here, * then the protocol-specific routine is called. */ static int arpintr(struct netmsg *msg) { struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet; struct arphdr *ar; u_short ar_hrd; if (m->m_len < sizeof(struct arphdr) && ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); goto out2; } ar = mtod(m, struct arphdr *); ar_hrd = ntohs(ar->ar_hrd); if (ar_hrd != ARPHRD_ETHER && ar_hrd != ARPHRD_IEEE802 && ar_hrd != ARPHRD_ARCNET) { log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n", (unsigned char *)&ar->ar_hrd, ""); goto out1; } if (m->m_pkthdr.len < arphdr_len(ar) && (m = m_pullup(m, arphdr_len(ar))) == NULL) { log(LOG_ERR, "arp: runt packet\n"); goto out1; } switch (ntohs(ar->ar_pro)) { #ifdef INET case ETHERTYPE_IP: in_arpinput(m); goto out2; #endif } out1: m_freem(m); out2: /* msg was embedded in the mbuf, do not reply! */ return(EASYNC); } #ifdef INET /* * ARP for Internet protocols on 10 Mb/s Ethernet. * Algorithm is that given in RFC 826. * In addition, a sanity check is performed on the sender * protocol address, to catch impersonators. * We no longer handle negotiations for use of trailer protocol: * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent * along with IP replies if we wanted trailers sent to us, * and also sent them in response to IP replies. * This allowed either end to announce the desire to receive * trailer packets. * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, * but formerly didn't normally send requests. */ static int log_arp_wrong_iface = 1; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, &log_arp_wrong_iface, 0, "log arp packets arriving on the wrong interface"); static void arp_update_oncpu(struct mbuf *m, in_addr_t saddr, boolean_t create, boolean_t dologging) { struct arphdr *ah = mtod(m, struct arphdr *); struct ifnet *ifp = m->m_pkthdr.rcvif; struct llinfo_arp *la; struct sockaddr_dl *sdl; struct rtentry *rt; int cpu = mycpuid; la = arplookup(saddr, create, FALSE); if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { struct in_addr isaddr = { saddr }; /* the following is not an error when doing bridging */ if (rt->rt_ifp != ifp) { if (dologging && log_arp_wrong_iface && cpu == 0) { log(LOG_ERR, "arp: %s is on %s " "but got reply from %*D on %s\n", inet_ntoa(isaddr), rt->rt_ifp->if_xname, ifp->if_addrlen, (u_char *)ar_sha(ah), ":", ifp->if_xname); } return; } if (sdl->sdl_alen && bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { if (rt->rt_expire != 0) { if (dologging && cpu == 0) { log(LOG_INFO, "arp: %s moved from %*D to %*D on %s\n", inet_ntoa(isaddr), ifp->if_addrlen, (u_char *)LLADDR(sdl), ":", ifp->if_addrlen, (u_char *)ar_sha(ah), ":", ifp->if_xname); } } else { if (dologging && cpu == 0) { log(LOG_ERR, "arp: %*D attempts to modify permanent entry for %s on %s\n", ifp->if_addrlen, (u_char *)ar_sha(ah), ":", inet_ntoa(isaddr), ifp->if_xname); } return; } } /* * sanity check for the address length. * XXX this does not work for protocols with variable address * length. -is */ if (dologging && sdl->sdl_alen && sdl->sdl_alen != ah->ar_hln && cpu == 0) { log(LOG_WARNING, "arp from %*D: new addr len %d, was %d", ifp->if_addrlen, (u_char *) ar_sha(ah), ":", ah->ar_hln, sdl->sdl_alen); } if (ifp->if_addrlen != ah->ar_hln) { if (dologging && cpu == 0) { log(LOG_WARNING, "arp from %*D: addr len: new %d, i/f %d (ignored)", ifp->if_addrlen, (u_char *) ar_sha(ah), ":", ah->ar_hln, ifp->if_addrlen); } return; } memcpy(LLADDR(sdl), ar_sha(ah), sdl->sdl_alen = ah->ar_hln); /* * If we receive an arp from a token-ring station over * a token-ring nic then try to save the source * routing info. */ if (ifp->if_type == IFT_ISO88025) { struct iso88025_header *th = (struct iso88025_header *)m->m_pkthdr.header; struct iso88025_sockaddr_dl_data *trld = SDL_ISO88025(sdl); int rif_len; rif_len = TR_RCF_RIFLEN(th->rcf); if ((th->iso88025_shost[0] & TR_RII) && (rif_len > 2)) { trld->trld_rcf = th->rcf; trld->trld_rcf ^= htons(TR_RCF_DIR); memcpy(trld->trld_route, th->rd, rif_len - 2); trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK); /* * Set up source routing information for * reply packet (XXX) */ m->m_data -= rif_len; m->m_len += rif_len; m->m_pkthdr.len += rif_len; } else { th->iso88025_shost[0] &= ~TR_RII; trld->trld_rcf = 0; } m->m_data -= 8; m->m_len += 8; m->m_pkthdr.len += 8; th->rcf = trld->trld_rcf; } if (rt->rt_expire != 0) rt->rt_expire = time_second + arpt_keep; rt->rt_flags &= ~RTF_REJECT; la->la_asked = 0; la->la_preempt = arp_maxtries; /* * This particular cpu might have been holding an mbuf * pending ARP resolution. If so, transmit the mbuf now. */ if (la->la_hold != NULL) { m_adj(la->la_hold, sizeof(struct ether_header)); lwkt_serialize_enter(ifp->if_serializer); (*ifp->if_output)(ifp, la->la_hold, rt_key(rt), rt); lwkt_serialize_exit(ifp->if_serializer); la->la_hold = NULL; } } } #ifdef SMP struct netmsg_arp_update { struct lwkt_msg lmsg; struct mbuf *m; in_addr_t saddr; boolean_t create; }; static int arp_update_msghandler(struct lwkt_msg *lmsg); #endif /* * Called from arpintr() - this routine is run from a single cpu. */ static void in_arpinput(struct mbuf *m) { struct arphdr *ah; struct ifnet *ifp = m->m_pkthdr.rcvif; struct ether_header *eh; struct arc_header *arh; struct iso88025_header *th = (struct iso88025_header *)NULL; struct rtentry *rt; struct ifaddr *ifa; struct in_ifaddr *ia; struct sockaddr sa; struct in_addr isaddr, itaddr, myaddr; #ifdef SMP struct netmsg_arp_update msg; #endif int op; int req_len; req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); return; } ah = mtod(m, struct arphdr *); op = ntohs(ah->ar_op); memcpy(&isaddr, ar_spa(ah), sizeof isaddr); memcpy(&itaddr, ar_tpa(ah), sizeof itaddr); /* * Check both target and sender IP addresses: * * If we receive the packet on the interface owning the address, * then accept the address. * * For a bridge, we accept the address if the receive interface and * the interface owning the address are on the same bridge. * (This will change slightly when we have clusters of interfaces). */ LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { /* Skip all ia's which don't match */ if (itaddr.s_addr != ia->ia_addr.sin_addr.s_addr) continue; if (ia->ia_ifp == ifp) goto match; if (ifp->if_bridge && ia->ia_ifp && ifp->if_bridge == ia->ia_ifp->if_bridge) goto match; } LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) { /* Skip all ia's which don't match */ if (isaddr.s_addr != ia->ia_addr.sin_addr.s_addr) continue; if (ia->ia_ifp == ifp) goto match; if (ifp->if_bridge && ia->ia_ifp && ifp->if_bridge == ia->ia_ifp->if_bridge) goto match; } /* * No match, use the first inet address on the receive interface * as a dummy address for the rest of the function. */ TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { ia = ifatoia(ifa); goto match; } } /* * If we got here, we didn't find any suitable interface, * so drop the packet. */ m_freem(m); return; match: myaddr = ia->ia_addr.sin_addr; if (!bcmp(ar_sha(ah), IF_LLADDR(ifp), ifp->if_addrlen)) { m_freem(m); /* it's from me, ignore it. */ return; } if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { log(LOG_ERR, "arp: link address is broadcast for IP address %s!\n", inet_ntoa(isaddr)); m_freem(m); return; } if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { log(LOG_ERR, "arp: %*D is using my IP address %s!\n", ifp->if_addrlen, (u_char *)ar_sha(ah), ":", inet_ntoa(isaddr)); itaddr = myaddr; goto reply; } #ifdef SMP lwkt_initmsg(&msg.lmsg, &curthread->td_msgport, 0, lwkt_cmd_func(arp_update_msghandler), lwkt_cmd_op_none); msg.m = m; msg.saddr = isaddr.s_addr; msg.create = (itaddr.s_addr == myaddr.s_addr); lwkt_domsg(rtable_portfn(0), &msg.lmsg); #endif arp_update_oncpu(m, isaddr.s_addr, (itaddr.s_addr == myaddr.s_addr), TRUE); reply: if (op != ARPOP_REQUEST) { m_freem(m); return; } if (itaddr.s_addr == myaddr.s_addr) { /* I am the target */ memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln); } else { struct llinfo_arp *la; la = arplookup(itaddr.s_addr, FALSE, SIN_PROXY); if (la == NULL) { struct sockaddr_in sin; if (!arp_proxyall) { m_freem(m); return; } bzero(&sin, sizeof sin); sin.sin_family = AF_INET; sin.sin_len = sizeof sin; sin.sin_addr = itaddr; rt = rtpurelookup((struct sockaddr *)&sin); if (rt == NULL) { m_freem(m); return; } --rt->rt_refcnt; /* * Don't send proxies for nodes on the same interface * as this one came out of, or we'll get into a fight * over who claims what Ether address. */ if (rt->rt_ifp == ifp) { m_freem(m); return; } memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); memcpy(ar_sha(ah), IF_LLADDR(ifp), ah->ar_hln); #ifdef DEBUG_PROXY printf("arp: proxying for %s\n", inet_ntoa(itaddr)); #endif } else { struct sockaddr_dl *sdl; rt = la->la_rt; memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); sdl = SDL(rt->rt_gateway); memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); } } memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); memcpy(ar_spa(ah), &itaddr, ah->ar_pln); ah->ar_op = htons(ARPOP_REPLY); ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ switch (ifp->if_type) { case IFT_ARCNET: arh = (struct arc_header *)sa.sa_data; arh->arc_dhost = *ar_tha(ah); arh->arc_type = ARCTYPE_ARP; break; case IFT_ISO88025: /* Re-arrange the source/dest address */ memcpy(th->iso88025_dhost, th->iso88025_shost, sizeof th->iso88025_dhost); memcpy(th->iso88025_shost, IF_LLADDR(ifp), sizeof th->iso88025_shost); /* Set the source routing bit if neccesary */ if (th->iso88025_dhost[0] & TR_RII) { th->iso88025_dhost[0] &= ~TR_RII; if (TR_RCF_RIFLEN(th->rcf) > 2) th->iso88025_shost[0] |= TR_RII; } /* Copy the addresses, ac and fc into sa_data */ memcpy(sa.sa_data, th->iso88025_dhost, (sizeof th->iso88025_dhost) * 2); sa.sa_data[(sizeof th->iso88025_dhost) * 2] = TR_AC; sa.sa_data[(sizeof th->iso88025_dhost) * 2 + 1] = TR_LLC_FRAME; break; case IFT_ETHER: case IFT_FDDI: /* * May not be correct for types not explictly * listed, but it is our best guess. */ default: eh = (struct ether_header *)sa.sa_data; memcpy(eh->ether_dhost, ar_tha(ah), sizeof eh->ether_dhost); eh->ether_type = htons(ETHERTYPE_ARP); break; } sa.sa_family = AF_UNSPEC; sa.sa_len = sizeof sa; lwkt_serialize_enter(ifp->if_serializer); (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); lwkt_serialize_exit(ifp->if_serializer); return; } #ifdef SMP static int arp_update_msghandler(struct lwkt_msg *lmsg) { struct netmsg_arp_update *msg = (struct netmsg_arp_update *)lmsg; int nextcpu; arp_update_oncpu(msg->m, msg->saddr, msg->create, FALSE); nextcpu = mycpuid + 1; if (nextcpu < ncpus) { lwkt_forwardmsg(rtable_portfn(nextcpu), &msg->lmsg); } else { lwkt_replymsg(&msg->lmsg, 0); } return (0); } #endif #endif /* * Free an arp entry. If the arp entry is actively referenced or represents * a static entry we only clear it back to an unresolved state, otherwise * we destroy the entry entirely. * * Note that static entries are created when route add ... -interface is used * to create an interface route to a (direct) destination. */ static void arptfree(struct llinfo_arp *la) { struct rtentry *rt = la->la_rt; struct sockaddr_dl *sdl; if (rt == NULL) panic("arptfree"); sdl = SDL(rt->rt_gateway); if (sdl != NULL && ((rt->rt_refcnt > 0 && sdl->sdl_family == AF_LINK) || (rt->rt_flags & RTF_STATIC))) { sdl->sdl_alen = 0; la->la_preempt = la->la_asked = 0; rt->rt_flags &= ~RTF_REJECT; return; } rtrequest(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 0, NULL); } /* * Lookup or enter a new address in arptab. */ static struct llinfo_arp * arplookup(in_addr_t addr, boolean_t create, boolean_t proxy) { struct rtentry *rt; struct sockaddr_inarp sin = { sizeof sin, AF_INET }; const char *why = NULL; sin.sin_addr.s_addr = addr; sin.sin_other = proxy ? SIN_PROXY : 0; if (create) rt = rtlookup((struct sockaddr *)&sin); else rt = rtpurelookup((struct sockaddr *)&sin); if (rt == NULL) return (NULL); rt->rt_refcnt--; if (rt->rt_flags & RTF_GATEWAY) why = "host is not on local network"; else if (!(rt->rt_flags & RTF_LLINFO)) why = "could not allocate llinfo"; else if (rt->rt_gateway->sa_family != AF_LINK) why = "gateway route is not ours"; if (why) { if (create) { log(LOG_DEBUG, "arplookup %s failed: %s\n", inet_ntoa(sin.sin_addr), why); } if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_WASCLONED)) { /* No references to this route. Purge it. */ rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL); } return (NULL); } return (rt->rt_llinfo); } void arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) { if (IA_SIN(ifa)->sin_addr.s_addr != INADDR_ANY) arprequest(ifp, &IA_SIN(ifa)->sin_addr, &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp)); ifa->ifa_rtrequest = arp_rtrequest; ifa->ifa_flags |= RTF_CLONING; } static void arp_init(void) { int cpu; for (cpu = 0; cpu < ncpus2; cpu++) LIST_INIT(&llinfo_arp_list[cpu]); netisr_register(NETISR_ARP, cpu0_portfn, arpintr); } SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0);