1c398230bSWarner Losh /*- 2df8bae1dSRodney W. Grimes * Copyright (c) 1982, 1986, 1988, 1993 3df8bae1dSRodney W. Grimes * The Regents of the University of California. All rights reserved. 4df8bae1dSRodney W. Grimes * 5df8bae1dSRodney W. Grimes * Redistribution and use in source and binary forms, with or without 6df8bae1dSRodney W. Grimes * modification, are permitted provided that the following conditions 7df8bae1dSRodney W. Grimes * are met: 8df8bae1dSRodney W. Grimes * 1. Redistributions of source code must retain the above copyright 9df8bae1dSRodney W. Grimes * notice, this list of conditions and the following disclaimer. 10df8bae1dSRodney W. Grimes * 2. Redistributions in binary form must reproduce the above copyright 11df8bae1dSRodney W. Grimes * notice, this list of conditions and the following disclaimer in the 12df8bae1dSRodney W. Grimes * documentation and/or other materials provided with the distribution. 13df8bae1dSRodney W. Grimes * 4. Neither the name of the University nor the names of its contributors 14df8bae1dSRodney W. Grimes * may be used to endorse or promote products derived from this software 15df8bae1dSRodney W. Grimes * without specific prior written permission. 16df8bae1dSRodney W. Grimes * 17df8bae1dSRodney W. Grimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18df8bae1dSRodney W. Grimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19df8bae1dSRodney W. Grimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20df8bae1dSRodney W. Grimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21df8bae1dSRodney W. Grimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22df8bae1dSRodney W. Grimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23df8bae1dSRodney W. Grimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24df8bae1dSRodney W. Grimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25df8bae1dSRodney W. Grimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26df8bae1dSRodney W. Grimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27df8bae1dSRodney W. Grimes * SUCH DAMAGE. 28df8bae1dSRodney W. Grimes * 29df8bae1dSRodney W. Grimes * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 30c3aac50fSPeter Wemm * $FreeBSD$ 31df8bae1dSRodney W. Grimes */ 32df8bae1dSRodney W. Grimes 33df8bae1dSRodney W. Grimes /* 34df8bae1dSRodney W. Grimes * Ethernet address resolution protocol. 35df8bae1dSRodney W. Grimes * TODO: 36df8bae1dSRodney W. Grimes * add "inuse/lock" bit (or ref. count) along with valid bit 37df8bae1dSRodney W. Grimes */ 38df8bae1dSRodney W. Grimes 391d5e9e22SEivind Eklund #include "opt_inet.h" 40b715f178SLuigi Rizzo #include "opt_bdg.h" 4119527d3eSRobert Watson #include "opt_mac.h" 42a9771948SGleb Smirnoff #include "opt_carp.h" 431d5e9e22SEivind Eklund 44df8bae1dSRodney W. Grimes #include <sys/param.h> 45df8bae1dSRodney W. Grimes #include <sys/kernel.h> 46ce02431fSDoug Rabson #include <sys/queue.h> 47885f1aa4SPoul-Henning Kamp #include <sys/sysctl.h> 48885f1aa4SPoul-Henning Kamp #include <sys/systm.h> 4919527d3eSRobert Watson #include <sys/mac.h> 50885f1aa4SPoul-Henning Kamp #include <sys/mbuf.h> 51885f1aa4SPoul-Henning Kamp #include <sys/malloc.h> 524458ac71SBruce Evans #include <sys/socket.h> 53885f1aa4SPoul-Henning Kamp #include <sys/syslog.h> 54df8bae1dSRodney W. Grimes 55df8bae1dSRodney W. Grimes #include <net/if.h> 56df8bae1dSRodney W. Grimes #include <net/if_dl.h> 57722012ccSJulian Elischer #include <net/if_types.h> 58df8bae1dSRodney W. Grimes #include <net/route.h> 59748e0b0aSGarrett Wollman #include <net/netisr.h> 60b149dd6cSLarry Lile #include <net/if_llc.h> 61c8f8e9c1SJulian Elischer #include <net/ethernet.h> 62c8f8e9c1SJulian Elischer #include <net/bridge.h> 63df8bae1dSRodney W. Grimes 64df8bae1dSRodney W. Grimes #include <netinet/in.h> 65df8bae1dSRodney W. Grimes #include <netinet/in_var.h> 66df8bae1dSRodney W. Grimes #include <netinet/if_ether.h> 67df8bae1dSRodney W. Grimes 68322dcb8dSMax Khon #include <net/if_arc.h> 69fda82fc2SJulian Elischer #include <net/iso88025.h> 70fda82fc2SJulian Elischer 71a9771948SGleb Smirnoff #ifdef DEV_CARP 72a9771948SGleb Smirnoff #include <netinet/ip_carp.h> 73a9771948SGleb Smirnoff #endif 74a9771948SGleb Smirnoff 75df8bae1dSRodney W. Grimes #define SIN(s) ((struct sockaddr_in *)s) 76df8bae1dSRodney W. Grimes #define SDL(s) ((struct sockaddr_dl *)s) 77df8bae1dSRodney W. Grimes 78ce02431fSDoug Rabson SYSCTL_DECL(_net_link_ether); 79602d513cSGarrett Wollman SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 80df8bae1dSRodney W. Grimes 81df8bae1dSRodney W. Grimes /* timer values */ 82602d513cSGarrett Wollman static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ 83602d513cSGarrett Wollman static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ 84602d513cSGarrett Wollman static int arpt_down = 20; /* once declared down, don't send for 20 sec */ 85885f1aa4SPoul-Henning Kamp 86602d513cSGarrett Wollman SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, 87602d513cSGarrett Wollman &arpt_prune, 0, ""); 88602d513cSGarrett Wollman SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 89602d513cSGarrett Wollman &arpt_keep, 0, ""); 90602d513cSGarrett Wollman SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, 91602d513cSGarrett Wollman &arpt_down, 0, ""); 92885f1aa4SPoul-Henning Kamp 93df8bae1dSRodney W. Grimes #define rt_expire rt_rmx.rmx_expire 94df8bae1dSRodney W. Grimes 9566800f57SGarrett Wollman struct llinfo_arp { 96e3975643SJake Burkholder LIST_ENTRY(llinfo_arp) la_le; 9766800f57SGarrett Wollman struct rtentry *la_rt; 9866800f57SGarrett Wollman struct mbuf *la_hold; /* last packet until resolved/timeout */ 99022695f8SOrion Hodson u_short la_preempt; /* countdown for pre-expiry arps */ 10073224fb0SOrion Hodson u_short la_asked; /* #times we QUERIED following expiration */ 10166800f57SGarrett Wollman #define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */ 10266800f57SGarrett Wollman }; 10366800f57SGarrett Wollman 104e3975643SJake Burkholder static LIST_HEAD(, llinfo_arp) llinfo_arp; 105df8bae1dSRodney W. Grimes 1061cafed39SJonathan Lemon static struct ifqueue arpintrq; 107d1dd20beSSam Leffler static int arp_allocated; 108df8bae1dSRodney W. Grimes 109885f1aa4SPoul-Henning Kamp static int arp_maxtries = 5; 110602d513cSGarrett Wollman static int useloopback = 1; /* use loopback interface for local traffic */ 111885f1aa4SPoul-Henning Kamp static int arp_proxyall = 0; 112d1dd20beSSam Leffler static struct callout arp_callout; 113602d513cSGarrett Wollman 114602d513cSGarrett Wollman SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 115602d513cSGarrett Wollman &arp_maxtries, 0, ""); 116602d513cSGarrett Wollman SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 117602d513cSGarrett Wollman &useloopback, 0, ""); 118602d513cSGarrett Wollman SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 119602d513cSGarrett Wollman &arp_proxyall, 0, ""); 120885f1aa4SPoul-Henning Kamp 1214d77a549SAlfred Perlstein static void arp_init(void); 1224d77a549SAlfred Perlstein static void arp_rtrequest(int, struct rtentry *, struct rt_addrinfo *); 1234d77a549SAlfred Perlstein static void arprequest(struct ifnet *, 1244d77a549SAlfred Perlstein struct in_addr *, struct in_addr *, u_char *); 1251cafed39SJonathan Lemon static void arpintr(struct mbuf *); 1264d77a549SAlfred Perlstein static void arptfree(struct llinfo_arp *); 1274d77a549SAlfred Perlstein static void arptimer(void *); 128885f1aa4SPoul-Henning Kamp static struct llinfo_arp 1294d77a549SAlfred Perlstein *arplookup(u_long, int, int); 1301d5e9e22SEivind Eklund #ifdef INET 1314d77a549SAlfred Perlstein static void in_arpinput(struct mbuf *); 1321d5e9e22SEivind Eklund #endif 13328e82295SGarrett Wollman 134df8bae1dSRodney W. Grimes /* 135df8bae1dSRodney W. Grimes * Timeout routine. Age arp_tab entries periodically. 136df8bae1dSRodney W. Grimes */ 137df8bae1dSRodney W. Grimes /* ARGSUSED */ 138df8bae1dSRodney W. Grimes static void 139df8bae1dSRodney W. Grimes arptimer(ignored_arg) 140df8bae1dSRodney W. Grimes void *ignored_arg; 141df8bae1dSRodney W. Grimes { 142c996428cSJeffrey Hsu struct llinfo_arp *la, *ola; 143df8bae1dSRodney W. Grimes 14493f79889SJeffrey Hsu RADIX_NODE_HEAD_LOCK(rt_tables[AF_INET]); 145c996428cSJeffrey Hsu la = LIST_FIRST(&llinfo_arp); 146c996428cSJeffrey Hsu while (la != NULL) { 147c996428cSJeffrey Hsu struct rtentry *rt = la->la_rt; 148c996428cSJeffrey Hsu ola = la; 149fc2ffbe6SPoul-Henning Kamp la = LIST_NEXT(la, la_le); 150227ee8a1SPoul-Henning Kamp if (rt->rt_expire && rt->rt_expire <= time_second) 15166800f57SGarrett Wollman arptfree(ola); /* timer has expired, clear */ 152df8bae1dSRodney W. Grimes } 15393f79889SJeffrey Hsu RADIX_NODE_HEAD_UNLOCK(rt_tables[AF_INET]); 154d1dd20beSSam Leffler 155d1dd20beSSam Leffler callout_reset(&arp_callout, arpt_prune * hz, arptimer, NULL); 156df8bae1dSRodney W. Grimes } 157df8bae1dSRodney W. Grimes 158df8bae1dSRodney W. Grimes /* 159df8bae1dSRodney W. Grimes * Parallel to llc_rtrequest. 160df8bae1dSRodney W. Grimes */ 161b2774d00SGarrett Wollman static void 1628071913dSRuslan Ermilov arp_rtrequest(req, rt, info) 163df8bae1dSRodney W. Grimes int req; 164e952fa39SMatthew N. Dodd struct rtentry *rt; 1658071913dSRuslan Ermilov struct rt_addrinfo *info; 166df8bae1dSRodney W. Grimes { 167e952fa39SMatthew N. Dodd struct sockaddr *gate; 168e952fa39SMatthew N. Dodd struct llinfo_arp *la; 169df8bae1dSRodney W. Grimes static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; 170067a8babSMax Laier struct in_ifaddr *ia; 171067a8babSMax Laier struct ifaddr *ifa; 172df8bae1dSRodney W. Grimes 173d1dd20beSSam Leffler RT_LOCK_ASSERT(rt); 174d1dd20beSSam Leffler 175df8bae1dSRodney W. Grimes if (rt->rt_flags & RTF_GATEWAY) 176df8bae1dSRodney W. Grimes return; 177d1dd20beSSam Leffler gate = rt->rt_gateway; 178d1dd20beSSam Leffler la = (struct llinfo_arp *)rt->rt_llinfo; 179df8bae1dSRodney W. Grimes switch (req) { 180df8bae1dSRodney W. Grimes 181df8bae1dSRodney W. Grimes case RTM_ADD: 182df8bae1dSRodney W. Grimes /* 183df8bae1dSRodney W. Grimes * XXX: If this is a manually added route to interface 184df8bae1dSRodney W. Grimes * such as older version of routed or gated might provide, 185df8bae1dSRodney W. Grimes * restore cloning bit. 186df8bae1dSRodney W. Grimes */ 187df8bae1dSRodney W. Grimes if ((rt->rt_flags & RTF_HOST) == 0 && 188d6fa5d28SBruce M Simpson rt_mask(rt) != NULL && 189df8bae1dSRodney W. Grimes SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) 190df8bae1dSRodney W. Grimes rt->rt_flags |= RTF_CLONING; 191df8bae1dSRodney W. Grimes if (rt->rt_flags & RTF_CLONING) { 192df8bae1dSRodney W. Grimes /* 193df8bae1dSRodney W. Grimes * Case 1: This route should come from a route to iface. 194df8bae1dSRodney W. Grimes */ 195df8bae1dSRodney W. Grimes rt_setgate(rt, rt_key(rt), 196df8bae1dSRodney W. Grimes (struct sockaddr *)&null_sdl); 197df8bae1dSRodney W. Grimes gate = rt->rt_gateway; 198df8bae1dSRodney W. Grimes SDL(gate)->sdl_type = rt->rt_ifp->if_type; 199df8bae1dSRodney W. Grimes SDL(gate)->sdl_index = rt->rt_ifp->if_index; 200227ee8a1SPoul-Henning Kamp rt->rt_expire = time_second; 201df8bae1dSRodney W. Grimes break; 202df8bae1dSRodney W. Grimes } 203df8bae1dSRodney W. Grimes /* Announce a new entry if requested. */ 204df8bae1dSRodney W. Grimes if (rt->rt_flags & RTF_ANNOUNCE) 205322dcb8dSMax Khon arprequest(rt->rt_ifp, 206ed7509acSJulian Elischer &SIN(rt_key(rt))->sin_addr, 207ed7509acSJulian Elischer &SIN(rt_key(rt))->sin_addr, 208df8bae1dSRodney W. Grimes (u_char *)LLADDR(SDL(gate))); 209df8bae1dSRodney W. Grimes /*FALLTHROUGH*/ 210df8bae1dSRodney W. Grimes case RTM_RESOLVE: 211df8bae1dSRodney W. Grimes if (gate->sa_family != AF_LINK || 212df8bae1dSRodney W. Grimes gate->sa_len < sizeof(null_sdl)) { 213d1dd20beSSam Leffler log(LOG_DEBUG, "%s: bad gateway %s%s\n", __func__, 214beb2ced8SBruce M Simpson inet_ntoa(SIN(rt_key(rt))->sin_addr), 215beb2ced8SBruce M Simpson (gate->sa_family != AF_LINK) ? 216c3b52d64SBruce M Simpson " (!AF_LINK)": ""); 217df8bae1dSRodney W. Grimes break; 218df8bae1dSRodney W. Grimes } 219df8bae1dSRodney W. Grimes SDL(gate)->sdl_type = rt->rt_ifp->if_type; 220df8bae1dSRodney W. Grimes SDL(gate)->sdl_index = rt->rt_ifp->if_index; 221df8bae1dSRodney W. Grimes if (la != 0) 222df8bae1dSRodney W. Grimes break; /* This happens on a route change */ 223df8bae1dSRodney W. Grimes /* 224df8bae1dSRodney W. Grimes * Case 2: This route may come from cloning, or a manual route 225df8bae1dSRodney W. Grimes * add with a LL address. 226df8bae1dSRodney W. Grimes */ 227d1dd20beSSam Leffler R_Zalloc(la, struct llinfo_arp *, sizeof(*la)); 228df8bae1dSRodney W. Grimes rt->rt_llinfo = (caddr_t)la; 229df8bae1dSRodney W. Grimes if (la == 0) { 230d1dd20beSSam Leffler log(LOG_DEBUG, "%s: malloc failed\n", __func__); 231df8bae1dSRodney W. Grimes break; 232df8bae1dSRodney W. Grimes } 233d1dd20beSSam Leffler arp_allocated++; 234df8bae1dSRodney W. Grimes la->la_rt = rt; 235df8bae1dSRodney W. Grimes rt->rt_flags |= RTF_LLINFO; 23693f79889SJeffrey Hsu RADIX_NODE_HEAD_LOCK_ASSERT(rt_tables[AF_INET]); 23766800f57SGarrett Wollman LIST_INSERT_HEAD(&llinfo_arp, la, la_le); 238cbb0b46aSGarrett Wollman 2391d5e9e22SEivind Eklund #ifdef INET 240cbb0b46aSGarrett Wollman /* 241cbb0b46aSGarrett Wollman * This keeps the multicast addresses from showing up 242cbb0b46aSGarrett Wollman * in `arp -a' listings as unresolved. It's not actually 243cbb0b46aSGarrett Wollman * functional. Then the same for broadcast. 244cbb0b46aSGarrett Wollman */ 245c448c89cSJonathan Lemon if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr)) && 246c448c89cSJonathan Lemon rt->rt_ifp->if_type != IFT_ARCNET) { 247cbb0b46aSGarrett Wollman ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, 248cbb0b46aSGarrett Wollman LLADDR(SDL(gate))); 249cbb0b46aSGarrett Wollman SDL(gate)->sdl_alen = 6; 25051a109a1SPeter Wemm rt->rt_expire = 0; 251cbb0b46aSGarrett Wollman } 252cbb0b46aSGarrett Wollman if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { 253322dcb8dSMax Khon memcpy(LLADDR(SDL(gate)), rt->rt_ifp->if_broadcastaddr, 254322dcb8dSMax Khon rt->rt_ifp->if_addrlen); 255322dcb8dSMax Khon SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen; 25651a109a1SPeter Wemm rt->rt_expire = 0; 257cbb0b46aSGarrett Wollman } 2581d5e9e22SEivind Eklund #endif 259cbb0b46aSGarrett Wollman 260067a8babSMax Laier TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) { 261067a8babSMax Laier if (ia->ia_ifp == rt->rt_ifp && 262067a8babSMax Laier SIN(rt_key(rt))->sin_addr.s_addr == 263067a8babSMax Laier (IA_SIN(ia))->sin_addr.s_addr) 264067a8babSMax Laier break; 265067a8babSMax Laier } 266067a8babSMax Laier if (ia) { 267df8bae1dSRodney W. Grimes /* 268df8bae1dSRodney W. Grimes * This test used to be 269df8bae1dSRodney W. Grimes * if (loif.if_flags & IFF_UP) 270df8bae1dSRodney W. Grimes * It allowed local traffic to be forced 271df8bae1dSRodney W. Grimes * through the hardware by configuring the loopback down. 272df8bae1dSRodney W. Grimes * However, it causes problems during network configuration 273df8bae1dSRodney W. Grimes * for boards that can't receive packets they send. 274df8bae1dSRodney W. Grimes * It is now necessary to clear "useloopback" and remove 275df8bae1dSRodney W. Grimes * the route to force traffic out to the hardware. 276df8bae1dSRodney W. Grimes */ 277df8bae1dSRodney W. Grimes rt->rt_expire = 0; 278ac912b2dSLuigi Rizzo bcopy(IF_LLADDR(rt->rt_ifp), LLADDR(SDL(gate)), 279322dcb8dSMax Khon SDL(gate)->sdl_alen = rt->rt_ifp->if_addrlen); 280df8bae1dSRodney W. Grimes if (useloopback) 281f5fea3ddSPaul Traina rt->rt_ifp = loif; 282df8bae1dSRodney W. Grimes 283067a8babSMax Laier /* 284067a8babSMax Laier * make sure to set rt->rt_ifa to the interface 285067a8babSMax Laier * address we are using, otherwise we will have trouble 286067a8babSMax Laier * with source address selection. 287067a8babSMax Laier */ 288067a8babSMax Laier ifa = &ia->ia_ifa; 289067a8babSMax Laier if (ifa != rt->rt_ifa) { 290067a8babSMax Laier IFAFREE(rt->rt_ifa); 291067a8babSMax Laier IFAREF(ifa); 292067a8babSMax Laier rt->rt_ifa = ifa; 293067a8babSMax Laier } 294df8bae1dSRodney W. Grimes } 295df8bae1dSRodney W. Grimes break; 296df8bae1dSRodney W. Grimes 297df8bae1dSRodney W. Grimes case RTM_DELETE: 298df8bae1dSRodney W. Grimes if (la == 0) 299df8bae1dSRodney W. Grimes break; 30093f79889SJeffrey Hsu RADIX_NODE_HEAD_LOCK_ASSERT(rt_tables[AF_INET]); 30166800f57SGarrett Wollman LIST_REMOVE(la, la_le); 302df8bae1dSRodney W. Grimes rt->rt_llinfo = 0; 303df8bae1dSRodney W. Grimes rt->rt_flags &= ~RTF_LLINFO; 304df8bae1dSRodney W. Grimes if (la->la_hold) 305df8bae1dSRodney W. Grimes m_freem(la->la_hold); 306df8bae1dSRodney W. Grimes Free((caddr_t)la); 307df8bae1dSRodney W. Grimes } 308df8bae1dSRodney W. Grimes } 309df8bae1dSRodney W. Grimes 310df8bae1dSRodney W. Grimes /* 311df8bae1dSRodney W. Grimes * Broadcast an ARP request. Caller specifies: 312df8bae1dSRodney W. Grimes * - arp header source ip address 313df8bae1dSRodney W. Grimes * - arp header target ip address 314df8bae1dSRodney W. Grimes * - arp header source ethernet address 315df8bae1dSRodney W. Grimes */ 316df8bae1dSRodney W. Grimes static void 317322dcb8dSMax Khon arprequest(ifp, sip, tip, enaddr) 318e952fa39SMatthew N. Dodd struct ifnet *ifp; 319e952fa39SMatthew N. Dodd struct in_addr *sip, *tip; 320e952fa39SMatthew N. Dodd u_char *enaddr; 321df8bae1dSRodney W. Grimes { 322e952fa39SMatthew N. Dodd struct mbuf *m; 323e952fa39SMatthew N. Dodd struct arphdr *ah; 324df8bae1dSRodney W. Grimes struct sockaddr sa; 325df8bae1dSRodney W. Grimes 326a163d034SWarner Losh if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 327df8bae1dSRodney W. Grimes return; 32864bf80ceSMatthew N. Dodd m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 32964bf80ceSMatthew N. Dodd 2*ifp->if_data.ifi_addrlen; 33064bf80ceSMatthew N. Dodd m->m_pkthdr.len = m->m_len; 33164bf80ceSMatthew N. Dodd MH_ALIGN(m, m->m_len); 33264bf80ceSMatthew N. Dodd ah = mtod(m, struct arphdr *); 33364bf80ceSMatthew N. Dodd bzero((caddr_t)ah, m->m_len); 33419527d3eSRobert Watson #ifdef MAC 33519527d3eSRobert Watson mac_create_mbuf_linklayer(ifp, m); 33619527d3eSRobert Watson #endif 337322dcb8dSMax Khon ah->ar_pro = htons(ETHERTYPE_IP); 338322dcb8dSMax Khon ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 339322dcb8dSMax Khon ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 340322dcb8dSMax Khon ah->ar_op = htons(ARPOP_REQUEST); 34164bf80ceSMatthew N. Dodd bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln); 34264bf80ceSMatthew N. Dodd bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln); 34364bf80ceSMatthew N. Dodd bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln); 34464bf80ceSMatthew N. Dodd sa.sa_family = AF_ARP; 34564bf80ceSMatthew N. Dodd sa.sa_len = 2; 34664bf80ceSMatthew N. Dodd m->m_flags |= M_BCAST; 347322dcb8dSMax Khon (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 34864bf80ceSMatthew N. Dodd 34964bf80ceSMatthew N. Dodd return; 350df8bae1dSRodney W. Grimes } 351df8bae1dSRodney W. Grimes 352df8bae1dSRodney W. Grimes /* 353cd46a114SLuigi Rizzo * Resolve an IP address into an ethernet address. 354cd46a114SLuigi Rizzo * On input: 355cd46a114SLuigi Rizzo * ifp is the interface we use 356cd46a114SLuigi Rizzo * dst is the next hop, 357cd46a114SLuigi Rizzo * rt0 is the route to the final destination (possibly useless) 358cd46a114SLuigi Rizzo * m is the mbuf 359cd46a114SLuigi Rizzo * desten is where we want the address. 360cd46a114SLuigi Rizzo * 361cd46a114SLuigi Rizzo * On success, desten is filled in and the function returns 0; 362cd46a114SLuigi Rizzo * If the packet must be held pending resolution, we return EWOULDBLOCK 363cd46a114SLuigi Rizzo * On other errors, we return the corresponding error code. 364df8bae1dSRodney W. Grimes */ 365df8bae1dSRodney W. Grimes int 366cd46a114SLuigi Rizzo arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 367f7c5baa1SLuigi Rizzo struct sockaddr *dst, u_char *desten) 368df8bae1dSRodney W. Grimes { 36908aadfbbSJonathan Lemon struct llinfo_arp *la = 0; 370df8bae1dSRodney W. Grimes struct sockaddr_dl *sdl; 371cd46a114SLuigi Rizzo int error; 372cd46a114SLuigi Rizzo struct rtentry *rt; 373cd46a114SLuigi Rizzo 374cd46a114SLuigi Rizzo error = rt_check(&rt, &rt0, dst); 375cd46a114SLuigi Rizzo if (error) { 376cd46a114SLuigi Rizzo m_freem(m); 377cd46a114SLuigi Rizzo return error; 378cd46a114SLuigi Rizzo } 379df8bae1dSRodney W. Grimes 380df8bae1dSRodney W. Grimes if (m->m_flags & M_BCAST) { /* broadcast */ 381322dcb8dSMax Khon (void)memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); 382cd46a114SLuigi Rizzo return (0); 383df8bae1dSRodney W. Grimes } 384322dcb8dSMax Khon if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) {/* multicast */ 385df8bae1dSRodney W. Grimes ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 386cd46a114SLuigi Rizzo return (0); 387df8bae1dSRodney W. Grimes } 388df8bae1dSRodney W. Grimes if (rt) 389df8bae1dSRodney W. Grimes la = (struct llinfo_arp *)rt->rt_llinfo; 390e7bc5f27SBill Fenner if (la == 0) { 391623ae52eSPoul-Henning Kamp la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0); 392623ae52eSPoul-Henning Kamp if (la) 393df8bae1dSRodney W. Grimes rt = la->la_rt; 394df8bae1dSRodney W. Grimes } 395df8bae1dSRodney W. Grimes if (la == 0 || rt == 0) { 396245086a0SPoul-Henning Kamp log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", 397245086a0SPoul-Henning Kamp inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "", 398245086a0SPoul-Henning Kamp rt ? "rt" : ""); 399df8bae1dSRodney W. Grimes m_freem(m); 400cd46a114SLuigi Rizzo return (EINVAL); /* XXX */ 401df8bae1dSRodney W. Grimes } 402df8bae1dSRodney W. Grimes sdl = SDL(rt->rt_gateway); 403df8bae1dSRodney W. Grimes /* 404df8bae1dSRodney W. Grimes * Check the address family and length is valid, the address 405df8bae1dSRodney W. Grimes * is resolved; otherwise, try to resolve. 406df8bae1dSRodney W. Grimes */ 407227ee8a1SPoul-Henning Kamp if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && 408df8bae1dSRodney W. Grimes sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { 409f0f3379eSOrion Hodson /* 410f0f3379eSOrion Hodson * If entry has an expiry time and it is approaching, 411f0f3379eSOrion Hodson * see if we need to send an ARP request within this 412f0f3379eSOrion Hodson * arpt_down interval. 413f0f3379eSOrion Hodson */ 414f0f3379eSOrion Hodson if ((rt->rt_expire != 0) && 415022695f8SOrion Hodson (time_second + la->la_preempt > rt->rt_expire)) { 416f0f3379eSOrion Hodson arprequest(ifp, 417f0f3379eSOrion Hodson &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 418f0f3379eSOrion Hodson &SIN(dst)->sin_addr, 419f0f3379eSOrion Hodson IF_LLADDR(ifp)); 420022695f8SOrion Hodson la->la_preempt--; 421f0f3379eSOrion Hodson } 422f0f3379eSOrion Hodson 4230453d3cbSBruce Evans bcopy(LLADDR(sdl), desten, sdl->sdl_alen); 424cd46a114SLuigi Rizzo return (0); 425df8bae1dSRodney W. Grimes } 426df8bae1dSRodney W. Grimes /* 427deb62e28SRuslan Ermilov * If ARP is disabled or static on this interface, stop. 42808aadfbbSJonathan Lemon * XXX 42908aadfbbSJonathan Lemon * Probably should not allocate empty llinfo struct if we are 43008aadfbbSJonathan Lemon * not going to be sending out an arp request. 43108aadfbbSJonathan Lemon */ 432deb62e28SRuslan Ermilov if (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) { 43347891de1SRuslan Ermilov m_freem(m); 434cd46a114SLuigi Rizzo return (EINVAL); 43547891de1SRuslan Ermilov } 43608aadfbbSJonathan Lemon /* 437df8bae1dSRodney W. Grimes * There is an arptab entry, but no ethernet address 438df8bae1dSRodney W. Grimes * response yet. Replace the held mbuf with this 439df8bae1dSRodney W. Grimes * latest one. 440df8bae1dSRodney W. Grimes */ 441df8bae1dSRodney W. Grimes if (la->la_hold) 442df8bae1dSRodney W. Grimes m_freem(la->la_hold); 443df8bae1dSRodney W. Grimes la->la_hold = m; 444df8bae1dSRodney W. Grimes if (rt->rt_expire) { 445d1dd20beSSam Leffler RT_LOCK(rt); 446df8bae1dSRodney W. Grimes rt->rt_flags &= ~RTF_REJECT; 447227ee8a1SPoul-Henning Kamp if (la->la_asked == 0 || rt->rt_expire != time_second) { 448227ee8a1SPoul-Henning Kamp rt->rt_expire = time_second; 44973224fb0SOrion Hodson if (la->la_asked++ < arp_maxtries) { 450322dcb8dSMax Khon arprequest(ifp, 451ed7509acSJulian Elischer &SIN(rt->rt_ifa->ifa_addr)->sin_addr, 452322dcb8dSMax Khon &SIN(dst)->sin_addr, 453322dcb8dSMax Khon IF_LLADDR(ifp)); 45473224fb0SOrion Hodson } else { 455df8bae1dSRodney W. Grimes rt->rt_flags |= RTF_REJECT; 456df8bae1dSRodney W. Grimes rt->rt_expire += arpt_down; 457022695f8SOrion Hodson la->la_asked = 0; 458022695f8SOrion Hodson la->la_preempt = arp_maxtries; 459df8bae1dSRodney W. Grimes } 460df8bae1dSRodney W. Grimes 461df8bae1dSRodney W. Grimes } 462d1dd20beSSam Leffler RT_UNLOCK(rt); 463df8bae1dSRodney W. Grimes } 464cd46a114SLuigi Rizzo return (EWOULDBLOCK); 465df8bae1dSRodney W. Grimes } 466df8bae1dSRodney W. Grimes 467df8bae1dSRodney W. Grimes /* 468df8bae1dSRodney W. Grimes * Common length and type checks are done here, 469df8bae1dSRodney W. Grimes * then the protocol-specific routine is called. 470df8bae1dSRodney W. Grimes */ 471885f1aa4SPoul-Henning Kamp static void 4721cafed39SJonathan Lemon arpintr(struct mbuf *m) 473df8bae1dSRodney W. Grimes { 4741cafed39SJonathan Lemon struct arphdr *ar; 475df8bae1dSRodney W. Grimes 47676ec7b2fSRobert Watson if (m->m_len < sizeof(struct arphdr) && 47784365e2bSMatthew Dillon ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { 478e44d6283SJoerg Wunsch log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 4791cafed39SJonathan Lemon return; 48076ec7b2fSRobert Watson } 48176ec7b2fSRobert Watson ar = mtod(m, struct arphdr *); 48276ec7b2fSRobert Watson 4831cafed39SJonathan Lemon if (ntohs(ar->ar_hrd) != ARPHRD_ETHER && 4841cafed39SJonathan Lemon ntohs(ar->ar_hrd) != ARPHRD_IEEE802 && 485b8b33234SDoug Rabson ntohs(ar->ar_hrd) != ARPHRD_ARCNET && 486b8b33234SDoug Rabson ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) { 4871cafed39SJonathan Lemon log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n", 48876ec7b2fSRobert Watson (unsigned char *)&ar->ar_hrd, ""); 48976ec7b2fSRobert Watson m_freem(m); 4901cafed39SJonathan Lemon return; 49176ec7b2fSRobert Watson } 49276ec7b2fSRobert Watson 49331175791SRuslan Ermilov if (m->m_len < arphdr_len(ar)) { 49478e2d2bdSRuslan Ermilov if ((m = m_pullup(m, arphdr_len(ar))) == NULL) { 495f72d9d83SJoerg Wunsch log(LOG_ERR, "arp: runt packet\n"); 49676ec7b2fSRobert Watson m_freem(m); 4971cafed39SJonathan Lemon return; 49876ec7b2fSRobert Watson } 49978e2d2bdSRuslan Ermilov ar = mtod(m, struct arphdr *); 50078e2d2bdSRuslan Ermilov } 501df8bae1dSRodney W. Grimes 502df8bae1dSRodney W. Grimes switch (ntohs(ar->ar_pro)) { 5031d5e9e22SEivind Eklund #ifdef INET 504df8bae1dSRodney W. Grimes case ETHERTYPE_IP: 505df8bae1dSRodney W. Grimes in_arpinput(m); 5061cafed39SJonathan Lemon return; 5071d5e9e22SEivind Eklund #endif 508df8bae1dSRodney W. Grimes } 509df8bae1dSRodney W. Grimes m_freem(m); 510df8bae1dSRodney W. Grimes } 511df8bae1dSRodney W. Grimes 5121d5e9e22SEivind Eklund #ifdef INET 513df8bae1dSRodney W. Grimes /* 514df8bae1dSRodney W. Grimes * ARP for Internet protocols on 10 Mb/s Ethernet. 515df8bae1dSRodney W. Grimes * Algorithm is that given in RFC 826. 516df8bae1dSRodney W. Grimes * In addition, a sanity check is performed on the sender 517df8bae1dSRodney W. Grimes * protocol address, to catch impersonators. 518df8bae1dSRodney W. Grimes * We no longer handle negotiations for use of trailer protocol: 519df8bae1dSRodney W. Grimes * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 520df8bae1dSRodney W. Grimes * along with IP replies if we wanted trailers sent to us, 521df8bae1dSRodney W. Grimes * and also sent them in response to IP replies. 522df8bae1dSRodney W. Grimes * This allowed either end to announce the desire to receive 523df8bae1dSRodney W. Grimes * trailer packets. 524df8bae1dSRodney W. Grimes * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 525df8bae1dSRodney W. Grimes * but formerly didn't normally send requests. 526df8bae1dSRodney W. Grimes */ 5273269187dSAlfred Perlstein static int log_arp_wrong_iface = 1; 528e3d123d6SAlfred Perlstein static int log_arp_movements = 1; 5293269187dSAlfred Perlstein 5303269187dSAlfred Perlstein SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 5313269187dSAlfred Perlstein &log_arp_wrong_iface, 0, 5323269187dSAlfred Perlstein "log arp packets arriving on the wrong interface"); 533e3d123d6SAlfred Perlstein SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, 534e3d123d6SAlfred Perlstein &log_arp_movements, 0, 53575ce3221SAlfred Perlstein "log arp replies from MACs different than the one in the cache"); 536e3d123d6SAlfred Perlstein 5373269187dSAlfred Perlstein 538df8bae1dSRodney W. Grimes static void 539df8bae1dSRodney W. Grimes in_arpinput(m) 540df8bae1dSRodney W. Grimes struct mbuf *m; 541df8bae1dSRodney W. Grimes { 542e952fa39SMatthew N. Dodd struct arphdr *ah; 543e952fa39SMatthew N. Dodd struct ifnet *ifp = m->m_pkthdr.rcvif; 544fda82fc2SJulian Elischer struct iso88025_header *th = (struct iso88025_header *)0; 54542fdfc12SKelly Yancey struct iso88025_sockaddr_dl_data *trld; 546e952fa39SMatthew N. Dodd struct llinfo_arp *la = 0; 547e952fa39SMatthew N. Dodd struct rtentry *rt; 548ca925d9cSJonathan Lemon struct ifaddr *ifa; 549ca925d9cSJonathan Lemon struct in_ifaddr *ia; 550df8bae1dSRodney W. Grimes struct sockaddr_dl *sdl; 551df8bae1dSRodney W. Grimes struct sockaddr sa; 552df8bae1dSRodney W. Grimes struct in_addr isaddr, itaddr, myaddr; 553a9771948SGleb Smirnoff u_int8_t *enaddr = NULL; 554b149dd6cSLarry Lile int op, rif_len; 555322dcb8dSMax Khon int req_len; 5562ef4a436SGleb Smirnoff int carp_match = 0; 557df8bae1dSRodney W. Grimes 558322dcb8dSMax Khon req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 559322dcb8dSMax Khon if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 5604cbc8ad1SYaroslav Tykhiy log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 5614cbc8ad1SYaroslav Tykhiy return; 5624cbc8ad1SYaroslav Tykhiy } 5634cbc8ad1SYaroslav Tykhiy 564322dcb8dSMax Khon ah = mtod(m, struct arphdr *); 565322dcb8dSMax Khon op = ntohs(ah->ar_op); 566322dcb8dSMax Khon (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 567322dcb8dSMax Khon (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 56832439868SGleb Smirnoff 569ca925d9cSJonathan Lemon /* 570ca925d9cSJonathan Lemon * For a bridge, we want to check the address irrespective 571ca925d9cSJonathan Lemon * of the receive interface. (This will change slightly 572ca925d9cSJonathan Lemon * when we have clusters of interfaces). 573a9771948SGleb Smirnoff * If the interface does not match, but the recieving interface 574a9771948SGleb Smirnoff * is part of carp, we call carp_iamatch to see if this is a 575a9771948SGleb Smirnoff * request for the virtual host ip. 576a9771948SGleb Smirnoff * XXX: This is really ugly! 577ca925d9cSJonathan Lemon */ 5782ef4a436SGleb Smirnoff LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { 5792ef4a436SGleb Smirnoff if ((do_bridge || (ia->ia_ifp == ifp)) && 5802ef4a436SGleb Smirnoff itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) 581ca925d9cSJonathan Lemon goto match; 5822ef4a436SGleb Smirnoff #ifdef DEV_CARP 5832ef4a436SGleb Smirnoff if (ifp->if_carp != NULL && 5842ef4a436SGleb Smirnoff carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) && 5852ef4a436SGleb Smirnoff itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) { 5862ef4a436SGleb Smirnoff carp_match = 1; 5872ef4a436SGleb Smirnoff goto match; 5882ef4a436SGleb Smirnoff } 5892ef4a436SGleb Smirnoff #endif 5902ef4a436SGleb Smirnoff } 591ca925d9cSJonathan Lemon LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) 59232439868SGleb Smirnoff if ((do_bridge || (ia->ia_ifp == ifp)) && 593ca925d9cSJonathan Lemon isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) 594ca925d9cSJonathan Lemon goto match; 595ca925d9cSJonathan Lemon /* 596d8b84d9eSJonathan Lemon * No match, use the first inet address on the receive interface 597ca925d9cSJonathan Lemon * as a dummy address for the rest of the function. 598ca925d9cSJonathan Lemon */ 599d8b84d9eSJonathan Lemon TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) 600ec691a10SJonathan Lemon if (ifa->ifa_addr && ifa->ifa_addr->sa_family == AF_INET) { 601ec691a10SJonathan Lemon ia = ifatoia(ifa); 602ec691a10SJonathan Lemon goto match; 603ec691a10SJonathan Lemon } 604ec691a10SJonathan Lemon /* 605ec691a10SJonathan Lemon * If bridging, fall back to using any inet address. 606ec691a10SJonathan Lemon */ 60732439868SGleb Smirnoff if (!do_bridge || (ia = TAILQ_FIRST(&in_ifaddrhead)) == NULL) 608b2a8ac7cSLuigi Rizzo goto drop; 609ca925d9cSJonathan Lemon match: 610a9771948SGleb Smirnoff if (!enaddr) 611a9771948SGleb Smirnoff enaddr = (u_int8_t *)IF_LLADDR(ifp); 612ca925d9cSJonathan Lemon myaddr = ia->ia_addr.sin_addr; 613a9771948SGleb Smirnoff if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) 614b2a8ac7cSLuigi Rizzo goto drop; /* it's from me, ignore it. */ 615322dcb8dSMax Khon if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 616df8bae1dSRodney W. Grimes log(LOG_ERR, 617322dcb8dSMax Khon "arp: link address is broadcast for IP address %s!\n", 618ef0cdf33SGarrett Wollman inet_ntoa(isaddr)); 619b2a8ac7cSLuigi Rizzo goto drop; 620df8bae1dSRodney W. Grimes } 62100fcf9d1SRobert Watson /* 62200fcf9d1SRobert Watson * Warn if another host is using the same IP address, but only if the 62300fcf9d1SRobert Watson * IP address isn't 0.0.0.0, which is used for DHCP only, in which 62400fcf9d1SRobert Watson * case we suppress the warning to avoid false positive complaints of 62500fcf9d1SRobert Watson * potential misconfiguration. 62600fcf9d1SRobert Watson */ 62700fcf9d1SRobert Watson if (isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 628df8bae1dSRodney W. Grimes log(LOG_ERR, 629322dcb8dSMax Khon "arp: %*D is using my IP address %s!\n", 630322dcb8dSMax Khon ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 631322dcb8dSMax Khon inet_ntoa(isaddr)); 632df8bae1dSRodney W. Grimes itaddr = myaddr; 633df8bae1dSRodney W. Grimes goto reply; 634df8bae1dSRodney W. Grimes } 635deb62e28SRuslan Ermilov if (ifp->if_flags & IFF_STATICARP) 636deb62e28SRuslan Ermilov goto reply; 637df8bae1dSRodney W. Grimes la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0); 638df8bae1dSRodney W. Grimes if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { 6397e1cd0d2SLuigi Rizzo /* the following is not an error when doing bridging */ 6402ef4a436SGleb Smirnoff if (!do_bridge && rt->rt_ifp != ifp && 6412ef4a436SGleb Smirnoff !(ifp->if_type == IFT_CARP && carp_match)) { 6423269187dSAlfred Perlstein if (log_arp_wrong_iface) 6439bf40edeSBrooks Davis log(LOG_ERR, "arp: %s is on %s but got reply from %*D on %s\n", 644dd9b6ddeSBill Fenner inet_ntoa(isaddr), 6459bf40edeSBrooks Davis rt->rt_ifp->if_xname, 646322dcb8dSMax Khon ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6479bf40edeSBrooks Davis ifp->if_xname); 648dd9b6ddeSBill Fenner goto reply; 649dd9b6ddeSBill Fenner } 650df8bae1dSRodney W. Grimes if (sdl->sdl_alen && 651322dcb8dSMax Khon bcmp(ar_sha(ah), LLADDR(sdl), sdl->sdl_alen)) { 652e3d123d6SAlfred Perlstein if (rt->rt_expire) { 653e3d123d6SAlfred Perlstein if (log_arp_movements) 6549bf40edeSBrooks Davis log(LOG_INFO, "arp: %s moved from %*D to %*D on %s\n", 655322dcb8dSMax Khon inet_ntoa(isaddr), 656322dcb8dSMax Khon ifp->if_addrlen, (u_char *)LLADDR(sdl), ":", 657322dcb8dSMax Khon ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6589bf40edeSBrooks Davis ifp->if_xname); 659e3d123d6SAlfred Perlstein } else { 660dd9b6ddeSBill Fenner log(LOG_ERR, 6619bf40edeSBrooks Davis "arp: %*D attempts to modify permanent entry for %s on %s\n", 662322dcb8dSMax Khon ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6639bf40edeSBrooks Davis inet_ntoa(isaddr), ifp->if_xname); 664dd9b6ddeSBill Fenner goto reply; 665dd9b6ddeSBill Fenner } 666dfd5dee1SPeter Wemm } 667322dcb8dSMax Khon /* 668322dcb8dSMax Khon * sanity check for the address length. 669322dcb8dSMax Khon * XXX this does not work for protocols with variable address 670322dcb8dSMax Khon * length. -is 671322dcb8dSMax Khon */ 672322dcb8dSMax Khon if (sdl->sdl_alen && 673322dcb8dSMax Khon sdl->sdl_alen != ah->ar_hln) { 674322dcb8dSMax Khon log(LOG_WARNING, 675322dcb8dSMax Khon "arp from %*D: new addr len %d, was %d", 676322dcb8dSMax Khon ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 677322dcb8dSMax Khon ah->ar_hln, sdl->sdl_alen); 678322dcb8dSMax Khon } 679322dcb8dSMax Khon if (ifp->if_addrlen != ah->ar_hln) { 680322dcb8dSMax Khon log(LOG_WARNING, 681322dcb8dSMax Khon "arp from %*D: addr len: new %d, i/f %d (ignored)", 682322dcb8dSMax Khon ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 683322dcb8dSMax Khon ah->ar_hln, ifp->if_addrlen); 684322dcb8dSMax Khon goto reply; 685322dcb8dSMax Khon } 686322dcb8dSMax Khon (void)memcpy(LLADDR(sdl), ar_sha(ah), 687322dcb8dSMax Khon sdl->sdl_alen = ah->ar_hln); 688243c4c6dSEivind Eklund /* 689243c4c6dSEivind Eklund * If we receive an arp from a token-ring station over 690243c4c6dSEivind Eklund * a token-ring nic then try to save the source 691243c4c6dSEivind Eklund * routing info. 692243c4c6dSEivind Eklund */ 693322dcb8dSMax Khon if (ifp->if_type == IFT_ISO88025) { 694fda82fc2SJulian Elischer th = (struct iso88025_header *)m->m_pkthdr.header; 69542fdfc12SKelly Yancey trld = SDL_ISO88025(sdl); 696b149dd6cSLarry Lile rif_len = TR_RCF_RIFLEN(th->rcf); 697b149dd6cSLarry Lile if ((th->iso88025_shost[0] & TR_RII) && 698b149dd6cSLarry Lile (rif_len > 2)) { 69942fdfc12SKelly Yancey trld->trld_rcf = th->rcf; 70042fdfc12SKelly Yancey trld->trld_rcf ^= htons(TR_RCF_DIR); 70142fdfc12SKelly Yancey memcpy(trld->trld_route, th->rd, rif_len - 2); 70242fdfc12SKelly Yancey trld->trld_rcf &= ~htons(TR_RCF_BCST_MASK); 703f9083fdbSLarry Lile /* 704f9083fdbSLarry Lile * Set up source routing information for 705f9083fdbSLarry Lile * reply packet (XXX) 706f9083fdbSLarry Lile */ 707b149dd6cSLarry Lile m->m_data -= rif_len; 708b149dd6cSLarry Lile m->m_len += rif_len; 709b149dd6cSLarry Lile m->m_pkthdr.len += rif_len; 710fda82fc2SJulian Elischer } else { 711b149dd6cSLarry Lile th->iso88025_shost[0] &= ~TR_RII; 712c3a2190cSKelly Yancey trld->trld_rcf = 0; 713fcf11853SLarry Lile } 714fda82fc2SJulian Elischer m->m_data -= 8; 715fda82fc2SJulian Elischer m->m_len += 8; 716fcf11853SLarry Lile m->m_pkthdr.len += 8; 71742fdfc12SKelly Yancey th->rcf = trld->trld_rcf; 718fda82fc2SJulian Elischer } 719d1dd20beSSam Leffler RT_LOCK(rt); 720df8bae1dSRodney W. Grimes if (rt->rt_expire) 721227ee8a1SPoul-Henning Kamp rt->rt_expire = time_second + arpt_keep; 722df8bae1dSRodney W. Grimes rt->rt_flags &= ~RTF_REJECT; 723d1dd20beSSam Leffler RT_UNLOCK(rt); 724022695f8SOrion Hodson la->la_asked = 0; 725022695f8SOrion Hodson la->la_preempt = arp_maxtries; 726df8bae1dSRodney W. Grimes if (la->la_hold) { 7272964fb65SMatthew N. Dodd (*ifp->if_output)(ifp, la->la_hold, rt_key(rt), rt); 728df8bae1dSRodney W. Grimes la->la_hold = 0; 729df8bae1dSRodney W. Grimes } 730df8bae1dSRodney W. Grimes } 731df8bae1dSRodney W. Grimes reply: 732b2a8ac7cSLuigi Rizzo if (op != ARPOP_REQUEST) 733b2a8ac7cSLuigi Rizzo goto drop; 734df8bae1dSRodney W. Grimes if (itaddr.s_addr == myaddr.s_addr) { 735df8bae1dSRodney W. Grimes /* I am the target */ 736322dcb8dSMax Khon (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 737a9771948SGleb Smirnoff (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln); 738df8bae1dSRodney W. Grimes } else { 739df8bae1dSRodney W. Grimes la = arplookup(itaddr.s_addr, 0, SIN_PROXY); 74028e82295SGarrett Wollman if (la == NULL) { 74128e82295SGarrett Wollman struct sockaddr_in sin; 74228e82295SGarrett Wollman 743b2a8ac7cSLuigi Rizzo if (!arp_proxyall) 744b2a8ac7cSLuigi Rizzo goto drop; 74528e82295SGarrett Wollman 74628e82295SGarrett Wollman bzero(&sin, sizeof sin); 74728e82295SGarrett Wollman sin.sin_family = AF_INET; 74828e82295SGarrett Wollman sin.sin_len = sizeof sin; 74928e82295SGarrett Wollman sin.sin_addr = itaddr; 75028e82295SGarrett Wollman 75131246bc2SGarrett Wollman rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 752b2a8ac7cSLuigi Rizzo if (!rt) 753b2a8ac7cSLuigi Rizzo goto drop; 75428e82295SGarrett Wollman /* 75528e82295SGarrett Wollman * Don't send proxies for nodes on the same interface 75628e82295SGarrett Wollman * as this one came out of, or we'll get into a fight 75728e82295SGarrett Wollman * over who claims what Ether address. 75828e82295SGarrett Wollman */ 759322dcb8dSMax Khon if (rt->rt_ifp == ifp) { 76028e82295SGarrett Wollman rtfree(rt); 761b2a8ac7cSLuigi Rizzo goto drop; 76228e82295SGarrett Wollman } 763322dcb8dSMax Khon (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 764a9771948SGleb Smirnoff (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln); 76528e82295SGarrett Wollman rtfree(rt); 766cc728227SDavid Malone 767cc728227SDavid Malone /* 768cc728227SDavid Malone * Also check that the node which sent the ARP packet 769cc728227SDavid Malone * is on the the interface we expect it to be on. This 770cc728227SDavid Malone * avoids ARP chaos if an interface is connected to the 771cc728227SDavid Malone * wrong network. 772cc728227SDavid Malone */ 773cc728227SDavid Malone sin.sin_addr = isaddr; 774cc728227SDavid Malone 775cc728227SDavid Malone rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); 776b2a8ac7cSLuigi Rizzo if (!rt) 777b2a8ac7cSLuigi Rizzo goto drop; 778322dcb8dSMax Khon if (rt->rt_ifp != ifp) { 779cc728227SDavid Malone log(LOG_INFO, "arp_proxy: ignoring request" 7809bf40edeSBrooks Davis " from %s via %s, expecting %s\n", 7819bf40edeSBrooks Davis inet_ntoa(isaddr), ifp->if_xname, 7829bf40edeSBrooks Davis rt->rt_ifp->if_xname); 783cc728227SDavid Malone rtfree(rt); 784b2a8ac7cSLuigi Rizzo goto drop; 785cc728227SDavid Malone } 786cc728227SDavid Malone rtfree(rt); 787cc728227SDavid Malone 788ac234f93SGarrett Wollman #ifdef DEBUG_PROXY 789ac234f93SGarrett Wollman printf("arp: proxying for %s\n", 790ef0cdf33SGarrett Wollman inet_ntoa(itaddr)); 791ac234f93SGarrett Wollman #endif 79228e82295SGarrett Wollman } else { 793df8bae1dSRodney W. Grimes rt = la->la_rt; 794322dcb8dSMax Khon (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 795df8bae1dSRodney W. Grimes sdl = SDL(rt->rt_gateway); 796322dcb8dSMax Khon (void)memcpy(ar_sha(ah), LLADDR(sdl), ah->ar_hln); 79728e82295SGarrett Wollman } 798df8bae1dSRodney W. Grimes } 799df8bae1dSRodney W. Grimes 800322dcb8dSMax Khon (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 801322dcb8dSMax Khon (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 802322dcb8dSMax Khon ah->ar_op = htons(ARPOP_REPLY); 803322dcb8dSMax Khon ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 80464bf80ceSMatthew N. Dodd m->m_flags &= ~(M_BCAST|M_MCAST); /* never reply by broadcast */ 80564bf80ceSMatthew N. Dodd m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 80664bf80ceSMatthew N. Dodd m->m_pkthdr.len = m->m_len; 80764bf80ceSMatthew N. Dodd sa.sa_family = AF_ARP; 80864bf80ceSMatthew N. Dodd sa.sa_len = 2; 809322dcb8dSMax Khon (*ifp->if_output)(ifp, m, &sa, (struct rtentry *)0); 810df8bae1dSRodney W. Grimes return; 811b2a8ac7cSLuigi Rizzo 812b2a8ac7cSLuigi Rizzo drop: 813b2a8ac7cSLuigi Rizzo m_freem(m); 814df8bae1dSRodney W. Grimes } 8151d5e9e22SEivind Eklund #endif 816df8bae1dSRodney W. Grimes 817df8bae1dSRodney W. Grimes /* 818df8bae1dSRodney W. Grimes * Free an arp entry. 819df8bae1dSRodney W. Grimes */ 820df8bae1dSRodney W. Grimes static void 821df8bae1dSRodney W. Grimes arptfree(la) 822e952fa39SMatthew N. Dodd struct llinfo_arp *la; 823df8bae1dSRodney W. Grimes { 824e952fa39SMatthew N. Dodd struct rtentry *rt = la->la_rt; 825e952fa39SMatthew N. Dodd struct sockaddr_dl *sdl; 826d1dd20beSSam Leffler 827df8bae1dSRodney W. Grimes if (rt == 0) 828df8bae1dSRodney W. Grimes panic("arptfree"); 829df8bae1dSRodney W. Grimes if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && 830df8bae1dSRodney W. Grimes sdl->sdl_family == AF_LINK) { 831df8bae1dSRodney W. Grimes sdl->sdl_alen = 0; 83273224fb0SOrion Hodson la->la_preempt = la->la_asked = 0; 833d1dd20beSSam Leffler RT_LOCK(rt); /* XXX needed or move higher? */ 834df8bae1dSRodney W. Grimes rt->rt_flags &= ~RTF_REJECT; 835d1dd20beSSam Leffler RT_UNLOCK(rt); 836df8bae1dSRodney W. Grimes return; 837df8bae1dSRodney W. Grimes } 838df8bae1dSRodney W. Grimes rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), 839df8bae1dSRodney W. Grimes 0, (struct rtentry **)0); 840df8bae1dSRodney W. Grimes } 841df8bae1dSRodney W. Grimes /* 842df8bae1dSRodney W. Grimes * Lookup or enter a new address in arptab. 843df8bae1dSRodney W. Grimes */ 844df8bae1dSRodney W. Grimes static struct llinfo_arp * 845df8bae1dSRodney W. Grimes arplookup(addr, create, proxy) 846df8bae1dSRodney W. Grimes u_long addr; 847df8bae1dSRodney W. Grimes int create, proxy; 848df8bae1dSRodney W. Grimes { 849e952fa39SMatthew N. Dodd struct rtentry *rt; 850d1dd20beSSam Leffler struct sockaddr_inarp sin; 851ac234f93SGarrett Wollman const char *why = 0; 852df8bae1dSRodney W. Grimes 853d1dd20beSSam Leffler bzero(&sin, sizeof(sin)); 854d1dd20beSSam Leffler sin.sin_len = sizeof(sin); 855d1dd20beSSam Leffler sin.sin_family = AF_INET; 856df8bae1dSRodney W. Grimes sin.sin_addr.s_addr = addr; 857d1dd20beSSam Leffler if (proxy) 858d1dd20beSSam Leffler sin.sin_other = SIN_PROXY; 85931246bc2SGarrett Wollman rt = rtalloc1((struct sockaddr *)&sin, create, 0UL); 860df8bae1dSRodney W. Grimes if (rt == 0) 861df8bae1dSRodney W. Grimes return (0); 862ac234f93SGarrett Wollman 863ac234f93SGarrett Wollman if (rt->rt_flags & RTF_GATEWAY) 864ac234f93SGarrett Wollman why = "host is not on local network"; 865ac234f93SGarrett Wollman else if ((rt->rt_flags & RTF_LLINFO) == 0) 866ac234f93SGarrett Wollman why = "could not allocate llinfo"; 867ac234f93SGarrett Wollman else if (rt->rt_gateway->sa_family != AF_LINK) 868ac234f93SGarrett Wollman why = "gateway route is not ours"; 869ac234f93SGarrett Wollman 870fedf1d01SBruce M Simpson if (why) { 871d1dd20beSSam Leffler #define ISDYNCLONE(_rt) \ 872d1dd20beSSam Leffler (((_rt)->rt_flags & (RTF_STATIC | RTF_WASCLONED)) == RTF_WASCLONED) 873d1dd20beSSam Leffler if (create) 874ac234f93SGarrett Wollman log(LOG_DEBUG, "arplookup %s failed: %s\n", 875ef0cdf33SGarrett Wollman inet_ntoa(sin.sin_addr), why); 876b75bead1SBruce M Simpson /* 877b75bead1SBruce M Simpson * If there are no references to this Layer 2 route, 878b75bead1SBruce M Simpson * and it is a cloned route, and not static, and 879b75bead1SBruce M Simpson * arplookup() is creating the route, then purge 880b75bead1SBruce M Simpson * it from the routing table as it is probably bogus. 881b75bead1SBruce M Simpson */ 8829c63e9dbSSam Leffler if (rt->rt_refcnt == 1 && ISDYNCLONE(rt)) 8839c63e9dbSSam Leffler rtexpunge(rt); 8849c63e9dbSSam Leffler RTFREE_LOCKED(rt); 885fedf1d01SBruce M Simpson return (0); 886d1dd20beSSam Leffler #undef ISDYNCLONE 887d1dd20beSSam Leffler } else { 8887138d65cSSam Leffler RT_REMREF(rt); 889d1dd20beSSam Leffler RT_UNLOCK(rt); 890df8bae1dSRodney W. Grimes return ((struct llinfo_arp *)rt->rt_llinfo); 891df8bae1dSRodney W. Grimes } 892d1dd20beSSam Leffler } 893df8bae1dSRodney W. Grimes 894dd2e4102SGarrett Wollman void 895322dcb8dSMax Khon arp_ifinit(ifp, ifa) 896322dcb8dSMax Khon struct ifnet *ifp; 897dd2e4102SGarrett Wollman struct ifaddr *ifa; 898dd2e4102SGarrett Wollman { 899dd570d4dSTor Egge if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) 900322dcb8dSMax Khon arprequest(ifp, &IA_SIN(ifa)->sin_addr, 901322dcb8dSMax Khon &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp)); 902dd2e4102SGarrett Wollman ifa->ifa_rtrequest = arp_rtrequest; 903dd2e4102SGarrett Wollman ifa->ifa_flags |= RTF_CLONING; 904dd2e4102SGarrett Wollman } 905df5e1987SJonathan Lemon 906a9771948SGleb Smirnoff void 907a9771948SGleb Smirnoff arp_ifinit2(ifp, ifa, enaddr) 908a9771948SGleb Smirnoff struct ifnet *ifp; 909a9771948SGleb Smirnoff struct ifaddr *ifa; 910a9771948SGleb Smirnoff u_char *enaddr; 911a9771948SGleb Smirnoff { 912a9771948SGleb Smirnoff if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) 913a9771948SGleb Smirnoff arprequest(ifp, &IA_SIN(ifa)->sin_addr, 914a9771948SGleb Smirnoff &IA_SIN(ifa)->sin_addr, enaddr); 915a9771948SGleb Smirnoff ifa->ifa_rtrequest = arp_rtrequest; 916a9771948SGleb Smirnoff ifa->ifa_flags |= RTF_CLONING; 917a9771948SGleb Smirnoff } 918a9771948SGleb Smirnoff 919df5e1987SJonathan Lemon static void 920df5e1987SJonathan Lemon arp_init(void) 921df5e1987SJonathan Lemon { 922df5e1987SJonathan Lemon 923df5e1987SJonathan Lemon arpintrq.ifq_maxlen = 50; 9246008862bSJohn Baldwin mtx_init(&arpintrq.ifq_mtx, "arp_inq", NULL, MTX_DEF); 925532cf61bSPeter Wemm LIST_INIT(&llinfo_arp); 926d1dd20beSSam Leffler callout_init(&arp_callout, CALLOUT_MPSAFE); 9277902224cSSam Leffler netisr_register(NETISR_ARP, arpintr, &arpintrq, NETISR_MPSAFE); 928cfff63f1SLuigi Rizzo callout_reset(&arp_callout, hz, arptimer, NULL); 929df5e1987SJonathan Lemon } 930df5e1987SJonathan Lemon SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 931