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 30df8bae1dSRodney W. Grimes */ 31df8bae1dSRodney W. Grimes 32df8bae1dSRodney W. Grimes /* 33df8bae1dSRodney W. Grimes * Ethernet address resolution protocol. 34df8bae1dSRodney W. Grimes * TODO: 35df8bae1dSRodney W. Grimes * add "inuse/lock" bit (or ref. count) along with valid bit 36df8bae1dSRodney W. Grimes */ 37df8bae1dSRodney W. Grimes 384b421e2dSMike Silbersack #include <sys/cdefs.h> 394b421e2dSMike Silbersack __FBSDID("$FreeBSD$"); 404b421e2dSMike Silbersack 411d5e9e22SEivind Eklund #include "opt_inet.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> 49885f1aa4SPoul-Henning Kamp #include <sys/mbuf.h> 50885f1aa4SPoul-Henning Kamp #include <sys/malloc.h> 51de34ad3fSJulian Elischer #include <sys/proc.h> 524458ac71SBruce Evans #include <sys/socket.h> 53885f1aa4SPoul-Henning Kamp #include <sys/syslog.h> 54603724d3SBjoern A. Zeeb #include <sys/vimage.h> 55df8bae1dSRodney W. Grimes 56df8bae1dSRodney W. Grimes #include <net/if.h> 57df8bae1dSRodney W. Grimes #include <net/if_dl.h> 58722012ccSJulian Elischer #include <net/if_types.h> 59748e0b0aSGarrett Wollman #include <net/netisr.h> 60b149dd6cSLarry Lile #include <net/if_llc.h> 61c8f8e9c1SJulian Elischer #include <net/ethernet.h> 625736e6fbSBjoern A. Zeeb #include <net/route.h> 63df8bae1dSRodney W. Grimes 64df8bae1dSRodney W. Grimes #include <netinet/in.h> 65df8bae1dSRodney W. Grimes #include <netinet/in_var.h> 666e6b3f7cSQing Li #include <net/if_llatbl.h> 67df8bae1dSRodney W. Grimes #include <netinet/if_ether.h> 68df8bae1dSRodney W. Grimes 69322dcb8dSMax Khon #include <net/if_arc.h> 70fda82fc2SJulian Elischer #include <net/iso88025.h> 71fda82fc2SJulian Elischer 72a9771948SGleb Smirnoff #ifdef DEV_CARP 73a9771948SGleb Smirnoff #include <netinet/ip_carp.h> 74a9771948SGleb Smirnoff #endif 75a9771948SGleb Smirnoff 76aed55708SRobert Watson #include <security/mac/mac_framework.h> 77aed55708SRobert Watson 78df8bae1dSRodney W. Grimes #define SIN(s) ((struct sockaddr_in *)s) 79df8bae1dSRodney W. Grimes #define SDL(s) ((struct sockaddr_dl *)s) 80df8bae1dSRodney W. Grimes 81ce02431fSDoug Rabson SYSCTL_DECL(_net_link_ether); 82602d513cSGarrett Wollman SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); 83df8bae1dSRodney W. Grimes 84df8bae1dSRodney W. Grimes /* timer values */ 85eddfbb76SRobert Watson static VNET_DEFINE(int, arpt_keep) = (20*60); /* once resolved, good for 20 86eddfbb76SRobert Watson * minutes */ 87eddfbb76SRobert Watson static VNET_DEFINE(int, arp_maxtries) = 5; 88eddfbb76SRobert Watson static VNET_DEFINE(int, useloopback) = 1; /* use loopback interface for 89eddfbb76SRobert Watson * local traffic */ 90eddfbb76SRobert Watson static VNET_DEFINE(int, arp_proxyall); 91885f1aa4SPoul-Henning Kamp 92eddfbb76SRobert Watson #define V_arpt_keep VNET_GET(arpt_keep) 93eddfbb76SRobert Watson #define V_arp_maxtries VNET_GET(arp_maxtries) 94eddfbb76SRobert Watson #define V_useloopback VNET_GET(useloopback) 95eddfbb76SRobert Watson #define V_arp_proxyall VNET_GET(arp_proxyall) 96885f1aa4SPoul-Henning Kamp 97eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, 98eddfbb76SRobert Watson &VNET_NAME(arpt_keep), 0, 99eddfbb76SRobert Watson "ARP entry lifetime in seconds"); 100eddfbb76SRobert Watson 101eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, 102eddfbb76SRobert Watson &VNET_NAME(arp_maxtries), 0, 1038b615593SMarko Zec "ARP resolution attempts before returning error"); 104eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, 105eddfbb76SRobert Watson &VNET_NAME(useloopback), 0, 1068b615593SMarko Zec "Use the loopback interface for local traffic"); 107eddfbb76SRobert Watson SYSCTL_VNET_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, 108eddfbb76SRobert Watson &VNET_NAME(arp_proxyall), 0, 1098b615593SMarko Zec "Enable proxy ARP for all suitable requests"); 110885f1aa4SPoul-Henning Kamp 1114d77a549SAlfred Perlstein static void arp_init(void); 1126e6b3f7cSQing Li void arprequest(struct ifnet *, 1134d77a549SAlfred Perlstein struct in_addr *, struct in_addr *, u_char *); 1141cafed39SJonathan Lemon static void arpintr(struct mbuf *); 1154d77a549SAlfred Perlstein static void arptimer(void *); 1161d5e9e22SEivind Eklund #ifdef INET 1174d77a549SAlfred Perlstein static void in_arpinput(struct mbuf *); 1181d5e9e22SEivind Eklund #endif 11928e82295SGarrett Wollman 120d4b5cae4SRobert Watson static const struct netisr_handler arp_nh = { 121d4b5cae4SRobert Watson .nh_name = "arp", 122d4b5cae4SRobert Watson .nh_handler = arpintr, 123d4b5cae4SRobert Watson .nh_proto = NETISR_ARP, 124d4b5cae4SRobert Watson .nh_policy = NETISR_POLICY_SOURCE, 125d4b5cae4SRobert Watson }; 126d4b5cae4SRobert Watson 1276e6b3f7cSQing Li #ifdef AF_INET 1286e6b3f7cSQing Li void arp_ifscrub(struct ifnet *ifp, uint32_t addr); 1296e6b3f7cSQing Li 130df8bae1dSRodney W. Grimes /* 1316e6b3f7cSQing Li * called by in_ifscrub to remove entry from the table when 1326e6b3f7cSQing Li * the interface goes away 1336e6b3f7cSQing Li */ 1346e6b3f7cSQing Li void 1356e6b3f7cSQing Li arp_ifscrub(struct ifnet *ifp, uint32_t addr) 1366e6b3f7cSQing Li { 1376e6b3f7cSQing Li struct sockaddr_in addr4; 1386e6b3f7cSQing Li 1396e6b3f7cSQing Li bzero((void *)&addr4, sizeof(addr4)); 1406e6b3f7cSQing Li addr4.sin_len = sizeof(addr4); 1416e6b3f7cSQing Li addr4.sin_family = AF_INET; 1426e6b3f7cSQing Li addr4.sin_addr.s_addr = addr; 14321ca7b57SMarko Zec CURVNET_SET(ifp->if_vnet); 1446e6b3f7cSQing Li IF_AFDATA_LOCK(ifp); 1456e6b3f7cSQing Li lla_lookup(LLTABLE(ifp), (LLE_DELETE | LLE_IFADDR), 1466e6b3f7cSQing Li (struct sockaddr *)&addr4); 1476e6b3f7cSQing Li IF_AFDATA_UNLOCK(ifp); 14821ca7b57SMarko Zec CURVNET_RESTORE(); 1496e6b3f7cSQing Li } 1506e6b3f7cSQing Li #endif 1516e6b3f7cSQing Li 1526e6b3f7cSQing Li /* 1536e6b3f7cSQing Li * Timeout routine. Age arp_tab entries periodically. 154df8bae1dSRodney W. Grimes */ 155df8bae1dSRodney W. Grimes static void 1561daaa65dSGleb Smirnoff arptimer(void *arg) 157df8bae1dSRodney W. Grimes { 1586e6b3f7cSQing Li struct ifnet *ifp; 1596e6b3f7cSQing Li struct llentry *lle = (struct llentry *)arg; 160df8bae1dSRodney W. Grimes 1616e6b3f7cSQing Li if (lle == NULL) { 1626e6b3f7cSQing Li panic("%s: NULL entry!\n", __func__); 163df8bae1dSRodney W. Grimes return; 1646e6b3f7cSQing Li } 1656e6b3f7cSQing Li ifp = lle->lle_tbl->llt_ifp; 1666e6b3f7cSQing Li IF_AFDATA_LOCK(ifp); 1676e6b3f7cSQing Li LLE_WLOCK(lle); 1685e96c0a1SKip Macy if (((lle->la_flags & LLE_DELETED) 1695e96c0a1SKip Macy || (time_second >= lle->la_expire)) 1705e96c0a1SKip Macy && (!callout_pending(&lle->la_timer) && 1715e96c0a1SKip Macy callout_active(&lle->la_timer))) 1726e6b3f7cSQing Li (void) llentry_free(lle); 1735e96c0a1SKip Macy else { 174df8bae1dSRodney W. Grimes /* 1756e6b3f7cSQing Li * Still valid, just drop our reference 176df8bae1dSRodney W. Grimes */ 1776e6b3f7cSQing Li LLE_FREE_LOCKED(lle); 178df8bae1dSRodney W. Grimes } 1796e6b3f7cSQing Li IF_AFDATA_UNLOCK(ifp); 180df8bae1dSRodney W. Grimes } 181df8bae1dSRodney W. Grimes 182df8bae1dSRodney W. Grimes /* 183df8bae1dSRodney W. Grimes * Broadcast an ARP request. Caller specifies: 184df8bae1dSRodney W. Grimes * - arp header source ip address 185df8bae1dSRodney W. Grimes * - arp header target ip address 186df8bae1dSRodney W. Grimes * - arp header source ethernet address 187df8bae1dSRodney W. Grimes */ 1886e6b3f7cSQing Li void 189f2565d68SRobert Watson arprequest(struct ifnet *ifp, struct in_addr *sip, struct in_addr *tip, 190f2565d68SRobert Watson u_char *enaddr) 191df8bae1dSRodney W. Grimes { 192e952fa39SMatthew N. Dodd struct mbuf *m; 193e952fa39SMatthew N. Dodd struct arphdr *ah; 194df8bae1dSRodney W. Grimes struct sockaddr sa; 195df8bae1dSRodney W. Grimes 1966e6b3f7cSQing Li if (sip == NULL) { 1976e6b3f7cSQing Li /* XXX don't believe this can happen (or explain why) */ 1986e6b3f7cSQing Li /* 1996e6b3f7cSQing Li * The caller did not supply a source address, try to find 2006e6b3f7cSQing Li * a compatible one among those assigned to this interface. 2016e6b3f7cSQing Li */ 2026e6b3f7cSQing Li struct ifaddr *ifa; 2036e6b3f7cSQing Li 2046e6b3f7cSQing Li TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { 2056e6b3f7cSQing Li if (!ifa->ifa_addr || 2066e6b3f7cSQing Li ifa->ifa_addr->sa_family != AF_INET) 2076e6b3f7cSQing Li continue; 2086e6b3f7cSQing Li sip = &SIN(ifa->ifa_addr)->sin_addr; 2096e6b3f7cSQing Li if (0 == ((sip->s_addr ^ tip->s_addr) & 2106e6b3f7cSQing Li SIN(ifa->ifa_netmask)->sin_addr.s_addr) ) 2116e6b3f7cSQing Li break; /* found it. */ 2126e6b3f7cSQing Li } 2136e6b3f7cSQing Li if (sip == NULL) { 2146e6b3f7cSQing Li printf("%s: cannot find matching address\n", __func__); 2156e6b3f7cSQing Li return; 2166e6b3f7cSQing Li } 2176e6b3f7cSQing Li } 2186e6b3f7cSQing Li 219a163d034SWarner Losh if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) 220df8bae1dSRodney W. Grimes return; 22164bf80ceSMatthew N. Dodd m->m_len = sizeof(*ah) + 2*sizeof(struct in_addr) + 22264bf80ceSMatthew N. Dodd 2*ifp->if_data.ifi_addrlen; 22364bf80ceSMatthew N. Dodd m->m_pkthdr.len = m->m_len; 22464bf80ceSMatthew N. Dodd MH_ALIGN(m, m->m_len); 22564bf80ceSMatthew N. Dodd ah = mtod(m, struct arphdr *); 22664bf80ceSMatthew N. Dodd bzero((caddr_t)ah, m->m_len); 22719527d3eSRobert Watson #ifdef MAC 228b9b0dac3SRobert Watson mac_netinet_arp_send(ifp, m); 22919527d3eSRobert Watson #endif 230322dcb8dSMax Khon ah->ar_pro = htons(ETHERTYPE_IP); 231322dcb8dSMax Khon ah->ar_hln = ifp->if_addrlen; /* hardware address length */ 232322dcb8dSMax Khon ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ 233322dcb8dSMax Khon ah->ar_op = htons(ARPOP_REQUEST); 23464bf80ceSMatthew N. Dodd bcopy((caddr_t)enaddr, (caddr_t)ar_sha(ah), ah->ar_hln); 23564bf80ceSMatthew N. Dodd bcopy((caddr_t)sip, (caddr_t)ar_spa(ah), ah->ar_pln); 23664bf80ceSMatthew N. Dodd bcopy((caddr_t)tip, (caddr_t)ar_tpa(ah), ah->ar_pln); 23764bf80ceSMatthew N. Dodd sa.sa_family = AF_ARP; 23864bf80ceSMatthew N. Dodd sa.sa_len = 2; 23964bf80ceSMatthew N. Dodd m->m_flags |= M_BCAST; 240279aa3d4SKip Macy (*ifp->if_output)(ifp, m, &sa, NULL); 241df8bae1dSRodney W. Grimes } 242df8bae1dSRodney W. Grimes 243df8bae1dSRodney W. Grimes /* 244cd46a114SLuigi Rizzo * Resolve an IP address into an ethernet address. 245cd46a114SLuigi Rizzo * On input: 246cd46a114SLuigi Rizzo * ifp is the interface we use 247cd46a114SLuigi Rizzo * rt0 is the route to the final destination (possibly useless) 248b6ae6984SJulian Elischer * m is the mbuf. May be NULL if we don't have a packet. 249b6ae6984SJulian Elischer * dst is the next hop, 250cd46a114SLuigi Rizzo * desten is where we want the address. 251cd46a114SLuigi Rizzo * 252cd46a114SLuigi Rizzo * On success, desten is filled in and the function returns 0; 253cd46a114SLuigi Rizzo * If the packet must be held pending resolution, we return EWOULDBLOCK 254cd46a114SLuigi Rizzo * On other errors, we return the corresponding error code. 255b6ae6984SJulian Elischer * Note that m_freem() handles NULL. 256df8bae1dSRodney W. Grimes */ 257df8bae1dSRodney W. Grimes int 258cd46a114SLuigi Rizzo arpresolve(struct ifnet *ifp, struct rtentry *rt0, struct mbuf *m, 2596e6b3f7cSQing Li struct sockaddr *dst, u_char *desten, struct llentry **lle) 260df8bae1dSRodney W. Grimes { 2616e6b3f7cSQing Li struct llentry *la = 0; 26200a46b31SKip Macy u_int flags = 0; 2636e6b3f7cSQing Li int error, renew; 264df8bae1dSRodney W. Grimes 2656e6b3f7cSQing Li *lle = NULL; 2666e6b3f7cSQing Li if (m != NULL) { 267b6ae6984SJulian Elischer if (m->m_flags & M_BCAST) { 268b6ae6984SJulian Elischer /* broadcast */ 269b6ae6984SJulian Elischer (void)memcpy(desten, 270b6ae6984SJulian Elischer ifp->if_broadcastaddr, ifp->if_addrlen); 271cd46a114SLuigi Rizzo return (0); 272df8bae1dSRodney W. Grimes } 273b6ae6984SJulian Elischer if (m->m_flags & M_MCAST && ifp->if_type != IFT_ARCNET) { 274b6ae6984SJulian Elischer /* multicast */ 275df8bae1dSRodney W. Grimes ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); 276cd46a114SLuigi Rizzo return (0); 277df8bae1dSRodney W. Grimes } 278b6ae6984SJulian Elischer } 2796e6b3f7cSQing Li /* XXXXX 28093fcb5a2SJulian Elischer */ 2816e6b3f7cSQing Li retry: 28200a46b31SKip Macy IF_AFDATA_RLOCK(ifp); 2836e6b3f7cSQing Li la = lla_lookup(LLTABLE(ifp), flags, dst); 28400a46b31SKip Macy IF_AFDATA_RUNLOCK(ifp); 28500a46b31SKip Macy if ((la == NULL) && ((flags & LLE_EXCLUSIVE) == 0) 28600a46b31SKip Macy && ((ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0)) { 28700a46b31SKip Macy flags |= (LLE_CREATE | LLE_EXCLUSIVE); 28800a46b31SKip Macy IF_AFDATA_WLOCK(ifp); 28900a46b31SKip Macy la = lla_lookup(LLTABLE(ifp), flags, dst); 29000a46b31SKip Macy IF_AFDATA_WUNLOCK(ifp); 29100a46b31SKip Macy } 2921ed7bf1eSGleb Smirnoff if (la == NULL) { 2936e6b3f7cSQing Li if (flags & LLE_CREATE) 2941ed7bf1eSGleb Smirnoff log(LOG_DEBUG, 2951ed7bf1eSGleb Smirnoff "arpresolve: can't allocate llinfo for %s\n", 2961ed7bf1eSGleb Smirnoff inet_ntoa(SIN(dst)->sin_addr)); 2971ed7bf1eSGleb Smirnoff m_freem(m); 2986e6b3f7cSQing Li return (EINVAL); 2991ed7bf1eSGleb Smirnoff } 300a20e2538SGleb Smirnoff 3016e6b3f7cSQing Li if ((la->la_flags & LLE_VALID) && 3026e6b3f7cSQing Li ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { 3036e6b3f7cSQing Li bcopy(&la->ll_addr, desten, ifp->if_addrlen); 304f0f3379eSOrion Hodson /* 305f0f3379eSOrion Hodson * If entry has an expiry time and it is approaching, 3066e6b3f7cSQing Li * see if we need to send an ARP request within this 3076e6b3f7cSQing Li * arpt_down interval. 308f0f3379eSOrion Hodson */ 3096e6b3f7cSQing Li if (!(la->la_flags & LLE_STATIC) && 3106e6b3f7cSQing Li time_uptime + la->la_preempt > la->la_expire) { 3116e6b3f7cSQing Li arprequest(ifp, NULL, 3126e6b3f7cSQing Li &SIN(dst)->sin_addr, IF_LLADDR(ifp)); 313a20e2538SGleb Smirnoff 314022695f8SOrion Hodson la->la_preempt--; 315f0f3379eSOrion Hodson } 316f0f3379eSOrion Hodson 3176e6b3f7cSQing Li *lle = la; 3186e6b3f7cSQing Li error = 0; 3196e6b3f7cSQing Li goto done; 320df8bae1dSRodney W. Grimes } 3216e6b3f7cSQing Li 3226e6b3f7cSQing Li if (la->la_flags & LLE_STATIC) { /* should not happen! */ 3236e6b3f7cSQing Li log(LOG_DEBUG, "arpresolve: ouch, empty static llinfo for %s\n", 3246e6b3f7cSQing Li inet_ntoa(SIN(dst)->sin_addr)); 32547891de1SRuslan Ermilov m_freem(m); 3266e6b3f7cSQing Li error = EINVAL; 3276e6b3f7cSQing Li goto done; 3286e6b3f7cSQing Li } 3296e6b3f7cSQing Li 3306e6b3f7cSQing Li renew = (la->la_asked == 0 || la->la_expire != time_uptime); 3316e6b3f7cSQing Li if ((renew || m != NULL) && (flags & LLE_EXCLUSIVE) == 0) { 3326e6b3f7cSQing Li flags |= LLE_EXCLUSIVE; 3336e6b3f7cSQing Li LLE_RUNLOCK(la); 3346e6b3f7cSQing Li goto retry; 33547891de1SRuslan Ermilov } 33608aadfbbSJonathan Lemon /* 337df8bae1dSRodney W. Grimes * There is an arptab entry, but no ethernet address 338df8bae1dSRodney W. Grimes * response yet. Replace the held mbuf with this 339df8bae1dSRodney W. Grimes * latest one. 340df8bae1dSRodney W. Grimes */ 3416e6b3f7cSQing Li if (m != NULL) { 3426e6b3f7cSQing Li if (la->la_hold != NULL) 343df8bae1dSRodney W. Grimes m_freem(la->la_hold); 344df8bae1dSRodney W. Grimes la->la_hold = m; 3456e6b3f7cSQing Li if (renew == 0 && (flags & LLE_EXCLUSIVE)) { 3466e6b3f7cSQing Li flags &= ~LLE_EXCLUSIVE; 3476e6b3f7cSQing Li LLE_DOWNGRADE(la); 34858505389SKip Macy } 349e1ff74c5SGleb Smirnoff 3506e6b3f7cSQing Li } 351e1ff74c5SGleb Smirnoff /* 352e1ff74c5SGleb Smirnoff * Return EWOULDBLOCK if we have tried less than arp_maxtries. It 353e1ff74c5SGleb Smirnoff * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH 354e1ff74c5SGleb Smirnoff * if we have already sent arp_maxtries ARP requests. Retransmit the 355e1ff74c5SGleb Smirnoff * ARP request, but not faster than one request per second. 356e1ff74c5SGleb Smirnoff */ 357603724d3SBjoern A. Zeeb if (la->la_asked < V_arp_maxtries) 358e1ff74c5SGleb Smirnoff error = EWOULDBLOCK; /* First request. */ 359e1ff74c5SGleb Smirnoff else 3606e6b3f7cSQing Li error = 3616e6b3f7cSQing Li (rt0->rt_flags & RTF_GATEWAY) ? EHOSTDOWN : EHOSTUNREACH; 362e1ff74c5SGleb Smirnoff 3636e6b3f7cSQing Li if (renew) { 3646e6b3f7cSQing Li LLE_ADDREF(la); 3656e6b3f7cSQing Li la->la_expire = time_uptime; 3666e6b3f7cSQing Li callout_reset(&la->la_timer, hz, arptimer, la); 36795ebcabeSMaxim Konovalov la->la_asked++; 3686e6b3f7cSQing Li LLE_WUNLOCK(la); 3696e6b3f7cSQing Li arprequest(ifp, NULL, &SIN(dst)->sin_addr, 370322dcb8dSMax Khon IF_LLADDR(ifp)); 3716e6b3f7cSQing Li return (error); 3726e6b3f7cSQing Li } 3736e6b3f7cSQing Li done: 3746e6b3f7cSQing Li if (flags & LLE_EXCLUSIVE) 3756e6b3f7cSQing Li LLE_WUNLOCK(la); 3766e6b3f7cSQing Li else 3776e6b3f7cSQing Li LLE_RUNLOCK(la); 378e1ff74c5SGleb Smirnoff return (error); 379df8bae1dSRodney W. Grimes } 380df8bae1dSRodney W. Grimes 381df8bae1dSRodney W. Grimes /* 382df8bae1dSRodney W. Grimes * Common length and type checks are done here, 383df8bae1dSRodney W. Grimes * then the protocol-specific routine is called. 384df8bae1dSRodney W. Grimes */ 385885f1aa4SPoul-Henning Kamp static void 3861cafed39SJonathan Lemon arpintr(struct mbuf *m) 387df8bae1dSRodney W. Grimes { 3881cafed39SJonathan Lemon struct arphdr *ar; 389df8bae1dSRodney W. Grimes 39076ec7b2fSRobert Watson if (m->m_len < sizeof(struct arphdr) && 39184365e2bSMatthew Dillon ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { 392e44d6283SJoerg Wunsch log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); 3931cafed39SJonathan Lemon return; 39476ec7b2fSRobert Watson } 39576ec7b2fSRobert Watson ar = mtod(m, struct arphdr *); 39676ec7b2fSRobert Watson 3971cafed39SJonathan Lemon if (ntohs(ar->ar_hrd) != ARPHRD_ETHER && 3981cafed39SJonathan Lemon ntohs(ar->ar_hrd) != ARPHRD_IEEE802 && 399b8b33234SDoug Rabson ntohs(ar->ar_hrd) != ARPHRD_ARCNET && 400b8b33234SDoug Rabson ntohs(ar->ar_hrd) != ARPHRD_IEEE1394) { 4011cafed39SJonathan Lemon log(LOG_ERR, "arp: unknown hardware address format (0x%2D)\n", 40276ec7b2fSRobert Watson (unsigned char *)&ar->ar_hrd, ""); 40376ec7b2fSRobert Watson m_freem(m); 4041cafed39SJonathan Lemon return; 40576ec7b2fSRobert Watson } 40676ec7b2fSRobert Watson 40731175791SRuslan Ermilov if (m->m_len < arphdr_len(ar)) { 40878e2d2bdSRuslan Ermilov if ((m = m_pullup(m, arphdr_len(ar))) == NULL) { 409f72d9d83SJoerg Wunsch log(LOG_ERR, "arp: runt packet\n"); 41076ec7b2fSRobert Watson m_freem(m); 4111cafed39SJonathan Lemon return; 41276ec7b2fSRobert Watson } 41378e2d2bdSRuslan Ermilov ar = mtod(m, struct arphdr *); 41478e2d2bdSRuslan Ermilov } 415df8bae1dSRodney W. Grimes 416df8bae1dSRodney W. Grimes switch (ntohs(ar->ar_pro)) { 4171d5e9e22SEivind Eklund #ifdef INET 418df8bae1dSRodney W. Grimes case ETHERTYPE_IP: 419df8bae1dSRodney W. Grimes in_arpinput(m); 4201cafed39SJonathan Lemon return; 4211d5e9e22SEivind Eklund #endif 422df8bae1dSRodney W. Grimes } 423df8bae1dSRodney W. Grimes m_freem(m); 424df8bae1dSRodney W. Grimes } 425df8bae1dSRodney W. Grimes 4261d5e9e22SEivind Eklund #ifdef INET 427df8bae1dSRodney W. Grimes /* 428df8bae1dSRodney W. Grimes * ARP for Internet protocols on 10 Mb/s Ethernet. 429df8bae1dSRodney W. Grimes * Algorithm is that given in RFC 826. 430df8bae1dSRodney W. Grimes * In addition, a sanity check is performed on the sender 431df8bae1dSRodney W. Grimes * protocol address, to catch impersonators. 432df8bae1dSRodney W. Grimes * We no longer handle negotiations for use of trailer protocol: 433df8bae1dSRodney W. Grimes * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent 434df8bae1dSRodney W. Grimes * along with IP replies if we wanted trailers sent to us, 435df8bae1dSRodney W. Grimes * and also sent them in response to IP replies. 436df8bae1dSRodney W. Grimes * This allowed either end to announce the desire to receive 437df8bae1dSRodney W. Grimes * trailer packets. 438df8bae1dSRodney W. Grimes * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, 439df8bae1dSRodney W. Grimes * but formerly didn't normally send requests. 440df8bae1dSRodney W. Grimes */ 4413269187dSAlfred Perlstein static int log_arp_wrong_iface = 1; 442e3d123d6SAlfred Perlstein static int log_arp_movements = 1; 44339393906SGleb Smirnoff static int log_arp_permanent_modify = 1; 4443269187dSAlfred Perlstein 4453269187dSAlfred Perlstein SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, 4463269187dSAlfred Perlstein &log_arp_wrong_iface, 0, 4473269187dSAlfred Perlstein "log arp packets arriving on the wrong interface"); 448e3d123d6SAlfred Perlstein SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, 449e3d123d6SAlfred Perlstein &log_arp_movements, 0, 45075ce3221SAlfred Perlstein "log arp replies from MACs different than the one in the cache"); 45139393906SGleb Smirnoff SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW, 45239393906SGleb Smirnoff &log_arp_permanent_modify, 0, 45339393906SGleb Smirnoff "log arp replies from MACs different than the one in the permanent arp entry"); 454e3d123d6SAlfred Perlstein 4553269187dSAlfred Perlstein 456df8bae1dSRodney W. Grimes static void 457f2565d68SRobert Watson in_arpinput(struct mbuf *m) 458df8bae1dSRodney W. Grimes { 459e952fa39SMatthew N. Dodd struct arphdr *ah; 460e952fa39SMatthew N. Dodd struct ifnet *ifp = m->m_pkthdr.rcvif; 4616e6b3f7cSQing Li struct llentry *la = NULL; 462e952fa39SMatthew N. Dodd struct rtentry *rt; 463ca925d9cSJonathan Lemon struct ifaddr *ifa; 464ca925d9cSJonathan Lemon struct in_ifaddr *ia; 465df8bae1dSRodney W. Grimes struct sockaddr sa; 466df8bae1dSRodney W. Grimes struct in_addr isaddr, itaddr, myaddr; 467a9771948SGleb Smirnoff u_int8_t *enaddr = NULL; 4686e6b3f7cSQing Li int op, flags; 4696e6b3f7cSQing Li struct mbuf *m0; 470322dcb8dSMax Khon int req_len; 47180b11ee4SPhilip Paeps int bridged = 0, is_bridge = 0; 472422a115aSGleb Smirnoff #ifdef DEV_CARP 4732ef4a436SGleb Smirnoff int carp_match = 0; 474422a115aSGleb Smirnoff #endif 4758e7e854cSKip Macy struct sockaddr_in sin; 4768e7e854cSKip Macy sin.sin_len = sizeof(struct sockaddr_in); 4778e7e854cSKip Macy sin.sin_family = AF_INET; 47829910a5aSKip Macy sin.sin_addr.s_addr = 0; 479df8bae1dSRodney W. Grimes 48074948aa6SAndrew Thompson if (ifp->if_bridge) 4818f867517SAndrew Thompson bridged = 1; 48280b11ee4SPhilip Paeps if (ifp->if_type == IFT_BRIDGE) 48380b11ee4SPhilip Paeps is_bridge = 1; 4848f867517SAndrew Thompson 485322dcb8dSMax Khon req_len = arphdr_len2(ifp->if_addrlen, sizeof(struct in_addr)); 486322dcb8dSMax Khon if (m->m_len < req_len && (m = m_pullup(m, req_len)) == NULL) { 4874cbc8ad1SYaroslav Tykhiy log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); 4884cbc8ad1SYaroslav Tykhiy return; 4894cbc8ad1SYaroslav Tykhiy } 4904cbc8ad1SYaroslav Tykhiy 491322dcb8dSMax Khon ah = mtod(m, struct arphdr *); 492322dcb8dSMax Khon op = ntohs(ah->ar_op); 493322dcb8dSMax Khon (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); 494322dcb8dSMax Khon (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); 49532439868SGleb Smirnoff 496ca925d9cSJonathan Lemon /* 497ca925d9cSJonathan Lemon * For a bridge, we want to check the address irrespective 498ca925d9cSJonathan Lemon * of the receive interface. (This will change slightly 499ca925d9cSJonathan Lemon * when we have clusters of interfaces). 500a9771948SGleb Smirnoff * If the interface does not match, but the recieving interface 501a9771948SGleb Smirnoff * is part of carp, we call carp_iamatch to see if this is a 502a9771948SGleb Smirnoff * request for the virtual host ip. 503a9771948SGleb Smirnoff * XXX: This is really ugly! 504ca925d9cSJonathan Lemon */ 5052d9cfabaSRobert Watson IN_IFADDR_RLOCK(); 5062ef4a436SGleb Smirnoff LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { 5077f2d8767SAndrew Thompson if (((bridged && ia->ia_ifp->if_bridge != NULL) || 5086e6b3f7cSQing Li ia->ia_ifp == ifp) && 50909d54778SRobert Watson itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) { 51009d54778SRobert Watson ifa_ref(&ia->ia_ifa); 5112d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 512ca925d9cSJonathan Lemon goto match; 51309d54778SRobert Watson } 5142ef4a436SGleb Smirnoff #ifdef DEV_CARP 5152ef4a436SGleb Smirnoff if (ifp->if_carp != NULL && 5162ef4a436SGleb Smirnoff carp_iamatch(ifp->if_carp, ia, &isaddr, &enaddr) && 5172ef4a436SGleb Smirnoff itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) { 5182ef4a436SGleb Smirnoff carp_match = 1; 51909d54778SRobert Watson ifa_ref(&ia->ia_ifa); 5202d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 5212ef4a436SGleb Smirnoff goto match; 5222ef4a436SGleb Smirnoff } 5232ef4a436SGleb Smirnoff #endif 5242ef4a436SGleb Smirnoff } 525ca925d9cSJonathan Lemon LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) 5267f2d8767SAndrew Thompson if (((bridged && ia->ia_ifp->if_bridge != NULL) || 5276e6b3f7cSQing Li ia->ia_ifp == ifp) && 52809d54778SRobert Watson isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) { 52909d54778SRobert Watson ifa_ref(&ia->ia_ifa); 5302d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 531ca925d9cSJonathan Lemon goto match; 53209d54778SRobert Watson } 53380b11ee4SPhilip Paeps 53480b11ee4SPhilip Paeps #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \ 53580b11ee4SPhilip Paeps (ia->ia_ifp->if_bridge == ifp->if_softc && \ 53680b11ee4SPhilip Paeps !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \ 53780b11ee4SPhilip Paeps addr == ia->ia_addr.sin_addr.s_addr) 53880b11ee4SPhilip Paeps /* 53980b11ee4SPhilip Paeps * Check the case when bridge shares its MAC address with 54080b11ee4SPhilip Paeps * some of its children, so packets are claimed by bridge 54180b11ee4SPhilip Paeps * itself (bridge_input() does it first), but they are really 54280b11ee4SPhilip Paeps * meant to be destined to the bridge member. 54380b11ee4SPhilip Paeps */ 54480b11ee4SPhilip Paeps if (is_bridge) { 54580b11ee4SPhilip Paeps LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { 54680b11ee4SPhilip Paeps if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) { 54709d54778SRobert Watson ifa_ref(&ia->ia_ifa); 54880b11ee4SPhilip Paeps ifp = ia->ia_ifp; 5492d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 55080b11ee4SPhilip Paeps goto match; 55180b11ee4SPhilip Paeps } 55280b11ee4SPhilip Paeps } 55380b11ee4SPhilip Paeps } 55480b11ee4SPhilip Paeps #undef BDG_MEMBER_MATCHES_ARP 5552d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 55680b11ee4SPhilip Paeps 557ca925d9cSJonathan Lemon /* 558d8b84d9eSJonathan Lemon * No match, use the first inet address on the receive interface 559ca925d9cSJonathan Lemon * as a dummy address for the rest of the function. 560ca925d9cSJonathan Lemon */ 56109d54778SRobert Watson IF_ADDR_LOCK(ifp); 562d8b84d9eSJonathan Lemon TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) 5634b97d7afSYaroslav Tykhiy if (ifa->ifa_addr->sa_family == AF_INET) { 564ec691a10SJonathan Lemon ia = ifatoia(ifa); 56509d54778SRobert Watson ifa_ref(ifa); 566f8574c7aSRobert Watson IF_ADDR_UNLOCK(ifp); 567ec691a10SJonathan Lemon goto match; 568ec691a10SJonathan Lemon } 56909d54778SRobert Watson IF_ADDR_UNLOCK(ifp); 57009d54778SRobert Watson 571ec691a10SJonathan Lemon /* 572ec691a10SJonathan Lemon * If bridging, fall back to using any inet address. 573ec691a10SJonathan Lemon */ 5742d9cfabaSRobert Watson IN_IFADDR_RLOCK(); 5752d9cfabaSRobert Watson if (!bridged || (ia = TAILQ_FIRST(&V_in_ifaddrhead)) == NULL) { 5762d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 577b2a8ac7cSLuigi Rizzo goto drop; 5782d9cfabaSRobert Watson } 57909d54778SRobert Watson ifa_ref(&ia->ia_ifa); 5802d9cfabaSRobert Watson IN_IFADDR_RUNLOCK(); 581ca925d9cSJonathan Lemon match: 582a9771948SGleb Smirnoff if (!enaddr) 583a9771948SGleb Smirnoff enaddr = (u_int8_t *)IF_LLADDR(ifp); 584ca925d9cSJonathan Lemon myaddr = ia->ia_addr.sin_addr; 58509d54778SRobert Watson ifa_free(&ia->ia_ifa); 586a9771948SGleb Smirnoff if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) 587b2a8ac7cSLuigi Rizzo goto drop; /* it's from me, ignore it. */ 588322dcb8dSMax Khon if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { 589df8bae1dSRodney W. Grimes log(LOG_ERR, 590322dcb8dSMax Khon "arp: link address is broadcast for IP address %s!\n", 591ef0cdf33SGarrett Wollman inet_ntoa(isaddr)); 592b2a8ac7cSLuigi Rizzo goto drop; 593df8bae1dSRodney W. Grimes } 59400fcf9d1SRobert Watson /* 59500fcf9d1SRobert Watson * Warn if another host is using the same IP address, but only if the 59600fcf9d1SRobert Watson * IP address isn't 0.0.0.0, which is used for DHCP only, in which 59700fcf9d1SRobert Watson * case we suppress the warning to avoid false positive complaints of 59800fcf9d1SRobert Watson * potential misconfiguration. 59900fcf9d1SRobert Watson */ 600f69453caSAndrew Thompson if (!bridged && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { 601df8bae1dSRodney W. Grimes log(LOG_ERR, 6023affb6fbSYaroslav Tykhiy "arp: %*D is using my IP address %s on %s!\n", 603322dcb8dSMax Khon ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6043affb6fbSYaroslav Tykhiy inet_ntoa(isaddr), ifp->if_xname); 605df8bae1dSRodney W. Grimes itaddr = myaddr; 606df8bae1dSRodney W. Grimes goto reply; 607df8bae1dSRodney W. Grimes } 608deb62e28SRuslan Ermilov if (ifp->if_flags & IFF_STATICARP) 609deb62e28SRuslan Ermilov goto reply; 6108b07e49aSJulian Elischer 6116e6b3f7cSQing Li bzero(&sin, sizeof(sin)); 6126e6b3f7cSQing Li sin.sin_len = sizeof(struct sockaddr_in); 6136e6b3f7cSQing Li sin.sin_family = AF_INET; 6146e6b3f7cSQing Li sin.sin_addr = isaddr; 6156e6b3f7cSQing Li flags = (itaddr.s_addr == myaddr.s_addr) ? LLE_CREATE : 0; 6166e6b3f7cSQing Li flags |= LLE_EXCLUSIVE; 6176e6b3f7cSQing Li IF_AFDATA_LOCK(ifp); 6186e6b3f7cSQing Li la = lla_lookup(LLTABLE(ifp), flags, (struct sockaddr *)&sin); 6196e6b3f7cSQing Li IF_AFDATA_UNLOCK(ifp); 6206e6b3f7cSQing Li if (la != NULL) { 6216e6b3f7cSQing Li /* the following is not an error when doing bridging */ 6226e6b3f7cSQing Li if (!bridged && la->lle_tbl->llt_ifp != ifp 623422a115aSGleb Smirnoff #ifdef DEV_CARP 624422a115aSGleb Smirnoff && (ifp->if_type != IFT_CARP || !carp_match) 625422a115aSGleb Smirnoff #endif 626422a115aSGleb Smirnoff ) { 6273269187dSAlfred Perlstein if (log_arp_wrong_iface) 6288b07e49aSJulian Elischer log(LOG_ERR, "arp: %s is on %s " 6296e6b3f7cSQing Li "but got reply from %*D on %s\n", 630dd9b6ddeSBill Fenner inet_ntoa(isaddr), 6316e6b3f7cSQing Li la->lle_tbl->llt_ifp->if_xname, 6326e6b3f7cSQing Li ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6339bf40edeSBrooks Davis ifp->if_xname); 6346e6b3f7cSQing Li goto reply; 635dd9b6ddeSBill Fenner } 6366e6b3f7cSQing Li if ((la->la_flags & LLE_VALID) && 6376e6b3f7cSQing Li bcmp(ar_sha(ah), &la->ll_addr, ifp->if_addrlen)) { 6386e6b3f7cSQing Li if (la->la_flags & LLE_STATIC) { 6398b07e49aSJulian Elischer log(LOG_ERR, 6406e6b3f7cSQing Li "arp: %*D attempts to modify permanent " 6416e6b3f7cSQing Li "entry for %s on %s\n", 6426e6b3f7cSQing Li ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6436e6b3f7cSQing Li inet_ntoa(isaddr), ifp->if_xname); 6446e6b3f7cSQing Li goto reply; 6456e6b3f7cSQing Li } 6466e6b3f7cSQing Li if (log_arp_movements) { 6476e6b3f7cSQing Li log(LOG_INFO, "arp: %s moved from %*D " 6486e6b3f7cSQing Li "to %*D on %s\n", 6498b07e49aSJulian Elischer inet_ntoa(isaddr), 6506e6b3f7cSQing Li ifp->if_addrlen, 6516e6b3f7cSQing Li (u_char *)&la->ll_addr, ":", 6526e6b3f7cSQing Li ifp->if_addrlen, (u_char *)ar_sha(ah), ":", 6538b07e49aSJulian Elischer ifp->if_xname); 654dd9b6ddeSBill Fenner } 655dfd5dee1SPeter Wemm } 6566e6b3f7cSQing Li 657322dcb8dSMax Khon if (ifp->if_addrlen != ah->ar_hln) { 658322dcb8dSMax Khon log(LOG_WARNING, 6596e6b3f7cSQing Li "arp from %*D: addr len: new %d, i/f %d (ignored)", 6606e6b3f7cSQing Li ifp->if_addrlen, (u_char *) ar_sha(ah), ":", 6616e6b3f7cSQing Li ah->ar_hln, ifp->if_addrlen); 6626e6b3f7cSQing Li goto reply; 663322dcb8dSMax Khon } 6646e6b3f7cSQing Li (void)memcpy(&la->ll_addr, ar_sha(ah), ifp->if_addrlen); 6656e6b3f7cSQing Li la->la_flags |= LLE_VALID; 6668b07e49aSJulian Elischer 6676e6b3f7cSQing Li if (!(la->la_flags & LLE_STATIC)) { 6686e6b3f7cSQing Li la->la_expire = time_uptime + V_arpt_keep; 669603724d3SBjoern A. Zeeb callout_reset(&la->la_timer, hz * V_arpt_keep, 6706e6b3f7cSQing Li arptimer, la); 6711daaa65dSGleb Smirnoff } 672022695f8SOrion Hodson la->la_asked = 0; 673603724d3SBjoern A. Zeeb la->la_preempt = V_arp_maxtries; 6746e6b3f7cSQing Li if (la->la_hold != NULL) { 6756e6b3f7cSQing Li m0 = la->la_hold; 6766e6b3f7cSQing Li la->la_hold = 0; 6776e6b3f7cSQing Li memcpy(&sa, L3_ADDR(la), sizeof(sa)); 6786e6b3f7cSQing Li LLE_WUNLOCK(la); 6798b07e49aSJulian Elischer 6806e6b3f7cSQing Li (*ifp->if_output)(ifp, m0, &sa, NULL); 6816e6b3f7cSQing Li return; 6826e6b3f7cSQing Li } 6836e6b3f7cSQing Li } 6846e6b3f7cSQing Li reply: 685b2a8ac7cSLuigi Rizzo if (op != ARPOP_REQUEST) 686b2a8ac7cSLuigi Rizzo goto drop; 6876e6b3f7cSQing Li 688df8bae1dSRodney W. Grimes if (itaddr.s_addr == myaddr.s_addr) { 6898b07e49aSJulian Elischer /* Shortcut.. the receiving interface is the target. */ 690322dcb8dSMax Khon (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 691a9771948SGleb Smirnoff (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln); 692df8bae1dSRodney W. Grimes } else { 693897d75c9SQing Li struct llentry *lle = NULL; 694897d75c9SQing Li 695603724d3SBjoern A. Zeeb if (!V_arp_proxyall) 696b2a8ac7cSLuigi Rizzo goto drop; 69728e82295SGarrett Wollman 69828e82295SGarrett Wollman sin.sin_addr = itaddr; 6998b07e49aSJulian Elischer /* XXX MRT use table 0 for arp reply */ 7008b07e49aSJulian Elischer rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0); 701b2a8ac7cSLuigi Rizzo if (!rt) 702b2a8ac7cSLuigi Rizzo goto drop; 703897d75c9SQing Li 70428e82295SGarrett Wollman /* 70528e82295SGarrett Wollman * Don't send proxies for nodes on the same interface 70628e82295SGarrett Wollman * as this one came out of, or we'll get into a fight 70728e82295SGarrett Wollman * over who claims what Ether address. 70828e82295SGarrett Wollman */ 709897d75c9SQing Li if (!rt->rt_ifp || rt->rt_ifp == ifp) { 7104e57bc33SChristian S.J. Peron RTFREE_LOCKED(rt); 711b2a8ac7cSLuigi Rizzo goto drop; 71228e82295SGarrett Wollman } 713897d75c9SQing Li IF_AFDATA_LOCK(rt->rt_ifp); 714897d75c9SQing Li lle = lla_lookup(LLTABLE(rt->rt_ifp), 0, (struct sockaddr *)&sin); 715897d75c9SQing Li IF_AFDATA_UNLOCK(rt->rt_ifp); 7164e57bc33SChristian S.J. Peron RTFREE_LOCKED(rt); 717cc728227SDavid Malone 718897d75c9SQing Li if (lle != NULL) { 719897d75c9SQing Li (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); 720897d75c9SQing Li (void)memcpy(ar_sha(ah), &lle->ll_addr, ah->ar_hln); 721897d75c9SQing Li LLE_RUNLOCK(lle); 722897d75c9SQing Li } else 723897d75c9SQing Li goto drop; 724897d75c9SQing Li 725cc728227SDavid Malone /* 726cc728227SDavid Malone * Also check that the node which sent the ARP packet 727cc728227SDavid Malone * is on the the interface we expect it to be on. This 728cc728227SDavid Malone * avoids ARP chaos if an interface is connected to the 729cc728227SDavid Malone * wrong network. 730cc728227SDavid Malone */ 731cc728227SDavid Malone sin.sin_addr = isaddr; 732cc728227SDavid Malone 7338b07e49aSJulian Elischer /* XXX MRT use table 0 for arp checks */ 7348b07e49aSJulian Elischer rt = in_rtalloc1((struct sockaddr *)&sin, 0, 0UL, 0); 735b2a8ac7cSLuigi Rizzo if (!rt) 736b2a8ac7cSLuigi Rizzo goto drop; 737322dcb8dSMax Khon if (rt->rt_ifp != ifp) { 738cc728227SDavid Malone log(LOG_INFO, "arp_proxy: ignoring request" 7399bf40edeSBrooks Davis " from %s via %s, expecting %s\n", 7409bf40edeSBrooks Davis inet_ntoa(isaddr), ifp->if_xname, 7419bf40edeSBrooks Davis rt->rt_ifp->if_xname); 7424e57bc33SChristian S.J. Peron RTFREE_LOCKED(rt); 743b2a8ac7cSLuigi Rizzo goto drop; 744cc728227SDavid Malone } 7454e57bc33SChristian S.J. Peron RTFREE_LOCKED(rt); 746cc728227SDavid Malone 747ac234f93SGarrett Wollman #ifdef DEBUG_PROXY 748ac234f93SGarrett Wollman printf("arp: proxying for %s\n", 749ef0cdf33SGarrett Wollman inet_ntoa(itaddr)); 750ac234f93SGarrett Wollman #endif 751df8bae1dSRodney W. Grimes } 752df8bae1dSRodney W. Grimes 7536e6b3f7cSQing Li if (la != NULL) 7546e6b3f7cSQing Li LLE_WUNLOCK(la); 755d0558157SBruce M Simpson if (itaddr.s_addr == myaddr.s_addr && 756d0558157SBruce M Simpson IN_LINKLOCAL(ntohl(itaddr.s_addr))) { 757d0558157SBruce M Simpson /* RFC 3927 link-local IPv4; always reply by broadcast. */ 758d0558157SBruce M Simpson #ifdef DEBUG_LINKLOCAL 759d0558157SBruce M Simpson printf("arp: sending reply for link-local addr %s\n", 760d0558157SBruce M Simpson inet_ntoa(itaddr)); 761d0558157SBruce M Simpson #endif 762d0558157SBruce M Simpson m->m_flags |= M_BCAST; 763d0558157SBruce M Simpson m->m_flags &= ~M_MCAST; 764d0558157SBruce M Simpson } else { 765d0558157SBruce M Simpson /* default behaviour; never reply by broadcast. */ 766d0558157SBruce M Simpson m->m_flags &= ~(M_BCAST|M_MCAST); 767d0558157SBruce M Simpson } 768322dcb8dSMax Khon (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); 769322dcb8dSMax Khon (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln); 770322dcb8dSMax Khon ah->ar_op = htons(ARPOP_REPLY); 771322dcb8dSMax Khon ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ 77264bf80ceSMatthew N. Dodd m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); 77364bf80ceSMatthew N. Dodd m->m_pkthdr.len = m->m_len; 77464bf80ceSMatthew N. Dodd sa.sa_family = AF_ARP; 77564bf80ceSMatthew N. Dodd sa.sa_len = 2; 776279aa3d4SKip Macy (*ifp->if_output)(ifp, m, &sa, NULL); 777df8bae1dSRodney W. Grimes return; 778b2a8ac7cSLuigi Rizzo 779b2a8ac7cSLuigi Rizzo drop: 7806e6b3f7cSQing Li if (la != NULL) 7816e6b3f7cSQing Li LLE_WUNLOCK(la); 782b2a8ac7cSLuigi Rizzo m_freem(m); 783df8bae1dSRodney W. Grimes } 7841d5e9e22SEivind Eklund #endif 785df8bae1dSRodney W. Grimes 786dd2e4102SGarrett Wollman void 787f2565d68SRobert Watson arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) 788dd2e4102SGarrett Wollman { 7896e6b3f7cSQing Li struct llentry *lle; 7906e6b3f7cSQing Li 791ce9122fdSQing Li if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) { 792322dcb8dSMax Khon arprequest(ifp, &IA_SIN(ifa)->sin_addr, 793322dcb8dSMax Khon &IA_SIN(ifa)->sin_addr, IF_LLADDR(ifp)); 7946e6b3f7cSQing Li /* 7956e6b3f7cSQing Li * interface address is considered static entry 7966e6b3f7cSQing Li * because the output of the arp utility shows 7976e6b3f7cSQing Li * that L2 entry as permanent 7986e6b3f7cSQing Li */ 7996e6b3f7cSQing Li IF_AFDATA_LOCK(ifp); 8006e6b3f7cSQing Li lle = lla_lookup(LLTABLE(ifp), (LLE_CREATE | LLE_IFADDR | LLE_STATIC), 8016e6b3f7cSQing Li (struct sockaddr *)IA_SIN(ifa)); 8026e6b3f7cSQing Li IF_AFDATA_UNLOCK(ifp); 8036e6b3f7cSQing Li if (lle == NULL) 8046e6b3f7cSQing Li log(LOG_INFO, "arp_ifinit: cannot create arp " 8056e6b3f7cSQing Li "entry for interface address\n"); 80686cd829dSKip Macy else 8076e6b3f7cSQing Li LLE_RUNLOCK(lle); 808ce9122fdSQing Li } 8096e6b3f7cSQing Li ifa->ifa_rtrequest = NULL; 810dd2e4102SGarrett Wollman } 811df5e1987SJonathan Lemon 812a9771948SGleb Smirnoff void 813f2565d68SRobert Watson arp_ifinit2(struct ifnet *ifp, struct ifaddr *ifa, u_char *enaddr) 814a9771948SGleb Smirnoff { 815a9771948SGleb Smirnoff if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) 816a9771948SGleb Smirnoff arprequest(ifp, &IA_SIN(ifa)->sin_addr, 817a9771948SGleb Smirnoff &IA_SIN(ifa)->sin_addr, enaddr); 8186e6b3f7cSQing Li ifa->ifa_rtrequest = NULL; 819a9771948SGleb Smirnoff } 820a9771948SGleb Smirnoff 8211ed81b73SMarko Zec static void 8221ed81b73SMarko Zec arp_init(void) 8231ed81b73SMarko Zec { 8241ed81b73SMarko Zec 825d4b5cae4SRobert Watson netisr_register(&arp_nh); 826df5e1987SJonathan Lemon } 827df5e1987SJonathan Lemon SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); 828