arp.c revision 89422
16735Samurai/* 26735Samurai * sys-bsd.c - System-dependent procedures for setting up 36735Samurai * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.) 46735Samurai * 56735Samurai * Copyright (c) 1989 Carnegie Mellon University. 66735Samurai * All rights reserved. 76735Samurai * 86735Samurai * Redistribution and use in source and binary forms are permitted 96735Samurai * provided that the above copyright notice and this paragraph are 106735Samurai * duplicated in all such forms and that any documentation, 116735Samurai * advertising materials, and other materials related to such 126735Samurai * distribution and use acknowledge that the software was developed 136735Samurai * by Carnegie Mellon University. The name of the 146735Samurai * University may not be used to endorse or promote products derived 156735Samurai * from this software without specific prior written permission. 166735Samurai * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 176735Samurai * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 186735Samurai * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 198857Srgrimes * 2050479Speter * $FreeBSD: head/usr.sbin/ppp/arp.c 89422 2002-01-16 14:03:52Z brian $ 218857Srgrimes * 226735Samurai */ 236735Samurai 246735Samurai/* 256735Samurai * TODO: 266735Samurai */ 276735Samurai 2843313Sbrian#include <sys/param.h> 296735Samurai#include <sys/socket.h> 306735Samurai#include <net/if.h> 316735Samurai#include <net/route.h> 326735Samurai#include <net/if_dl.h> 336735Samurai#include <netinet/in.h> 346735Samurai#include <netinet/if_ether.h> 3532721Sbrian#include <arpa/inet.h> 3636285Sbrian#include <netinet/in_systm.h> 3736285Sbrian#include <netinet/ip.h> 3836285Sbrian#include <sys/un.h> 3930715Sbrian 4046085Sbrian#include <errno.h> 4130715Sbrian#include <stdio.h> 4232616Sbrian#include <stdlib.h> 4330715Sbrian#include <string.h> 4432616Sbrian#include <sys/sysctl.h> 4546686Sbrian#include <termios.h> 4630715Sbrian#include <unistd.h> 4730715Sbrian 4846686Sbrian#include "layer.h" 4930715Sbrian#include "mbuf.h" 5029265Sbrian#include "log.h" 5131061Sbrian#include "id.h" 5236285Sbrian#include "timer.h" 5336285Sbrian#include "fsm.h" 5436285Sbrian#include "defs.h" 5536285Sbrian#include "iplist.h" 5636285Sbrian#include "throughput.h" 5736285Sbrian#include "slcompress.h" 5838557Sbrian#include "lqr.h" 5938557Sbrian#include "hdlc.h" 6081634Sbrian#include "ncpaddr.h" 6136285Sbrian#include "ipcp.h" 6281634Sbrian#include "ipv6cp.h" 6336285Sbrian#include "descriptor.h" 6436285Sbrian#include "lcp.h" 6536285Sbrian#include "ccp.h" 6636285Sbrian#include "link.h" 6736285Sbrian#include "mp.h" 6881634Sbrian#include "ncp.h" 6981634Sbrian#include "filter.h" 7043313Sbrian#ifndef NORADIUS 7143313Sbrian#include "radius.h" 7243313Sbrian#endif 7336285Sbrian#include "bundle.h" 7458032Sbrian#include "iface.h" 7530715Sbrian#include "arp.h" 766735Samurai 7732616Sbrian/* 786735Samurai * SET_SA_FAMILY - set the sa_family field of a struct sockaddr, 796735Samurai * if it exists. 806735Samurai */ 816735Samurai#define SET_SA_FAMILY(addr, family) \ 8230715Sbrian memset((char *) &(addr), '\0', sizeof(addr)); \ 836735Samurai addr.sa_family = (family); \ 846735Samurai addr.sa_len = sizeof(addr); 856735Samurai 866735Samurai 876735Samurai#if RTM_VERSION >= 3 886735Samurai 896735Samurai/* 9036285Sbrian * arp_SetProxy - Make a proxy ARP entry for the peer. 916735Samurai */ 926735Samuraistatic struct { 9328679Sbrian struct rt_msghdr hdr; 9428679Sbrian struct sockaddr_inarp dst; 9528679Sbrian struct sockaddr_dl hwa; 9628679Sbrian char extra[128]; 9730715Sbrian} arpmsg; 986735Samurai 9940665Sbrianstatic int 10040665Sbrianarp_ProxySub(struct bundle *bundle, struct in_addr addr, int add, int s) 1016735Samurai{ 10228679Sbrian int routes; 1036735Samurai 10428679Sbrian /* 10528679Sbrian * Get the hardware address of an interface on the same subnet as our local 10628679Sbrian * address. 10728679Sbrian */ 10840665Sbrian 10931962Sbrian memset(&arpmsg, 0, sizeof arpmsg); 11080730Sbrian if (!arp_EtherAddr(s, addr, &arpmsg.hwa, 0)) { 11140665Sbrian log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n", 11240665Sbrian inet_ntoa(addr)); 11328679Sbrian return 0; 11428679Sbrian } 11589422Sbrian routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET); 11631061Sbrian if (routes < 0) { 11736285Sbrian log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n", 11828679Sbrian strerror(errno)); 11928679Sbrian return 0; 12028679Sbrian } 12140665Sbrian arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE; 12228679Sbrian arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC; 12328679Sbrian arpmsg.hdr.rtm_version = RTM_VERSION; 12436285Sbrian arpmsg.hdr.rtm_seq = ++bundle->routing_seq; 12528679Sbrian arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY; 12628679Sbrian arpmsg.hdr.rtm_inits = RTV_EXPIRE; 12728679Sbrian arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp); 12828679Sbrian arpmsg.dst.sin_family = AF_INET; 12936285Sbrian arpmsg.dst.sin_addr.s_addr = addr.s_addr; 13028679Sbrian arpmsg.dst.sin_other = SIN_PROXY; 1316735Samurai 13228679Sbrian arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg 13328679Sbrian + arpmsg.hwa.sdl_len; 13440665Sbrian 13540665Sbrian 13683775Sru if (ID0write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 && 13740665Sbrian !(!add && errno == ESRCH)) { 13840665Sbrian log_Printf(LogERROR, "%s proxy arp entry %s: %s\n", 13940665Sbrian add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno)); 1406735Samurai close(routes); 14128679Sbrian return 0; 14228679Sbrian } 14328679Sbrian close(routes); 14428679Sbrian return 1; 1456735Samurai} 1466735Samurai 14740665Sbrianint 14840665Sbrianarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 14940665Sbrian{ 15040665Sbrian return (arp_ProxySub(bundle, addr, 1, s)); 15140665Sbrian} 15240665Sbrian 1536735Samurai/* 15436285Sbrian * arp_ClearProxy - Delete the proxy ARP entry for the peer. 1556735Samurai */ 1566735Samuraiint 15736285Sbrianarp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 1586735Samurai{ 15940665Sbrian return (arp_ProxySub(bundle, addr, 0, s)); 1606735Samurai} 1616735Samurai 16228679Sbrian#else /* RTM_VERSION */ 1636735Samurai 1646735Samurai/* 16536285Sbrian * arp_SetProxy - Make a proxy ARP entry for the peer. 1666735Samurai */ 1676735Samuraiint 16836285Sbrianarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 1696735Samurai{ 17028679Sbrian struct arpreq arpreq; 17128679Sbrian struct { 17228679Sbrian struct sockaddr_dl sdl; 17328679Sbrian char space[128]; 17428679Sbrian } dls; 1756735Samurai 17631962Sbrian memset(&arpreq, '\0', sizeof arpreq); 1776735Samurai 17828679Sbrian /* 17928679Sbrian * Get the hardware address of an interface on the same subnet as our local 18028679Sbrian * address. 18128679Sbrian */ 18280730Sbrian if (!arp_EtherAddr(s, addr, &dls.sdl, 1)) { 18367912Sbrian log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for " 18467912Sbrian "proxy ARP\n"); 18528679Sbrian return 0; 18628679Sbrian } 18728679Sbrian arpreq.arp_ha.sa_len = sizeof(struct sockaddr); 18828679Sbrian arpreq.arp_ha.sa_family = AF_UNSPEC; 18930715Sbrian memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen); 19028679Sbrian SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 19136285Sbrian ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 19228679Sbrian arpreq.arp_flags = ATF_PERM | ATF_PUBL; 19336285Sbrian if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) { 19437019Sbrian log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n", 19537019Sbrian strerror(errno)); 19628679Sbrian return 0; 19728679Sbrian } 19828679Sbrian return 1; 1996735Samurai} 2006735Samurai 2016735Samurai/* 20236285Sbrian * arp_ClearProxy - Delete the proxy ARP entry for the peer. 2036735Samurai */ 2046735Samuraiint 20536285Sbrianarp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 2066735Samurai{ 20728679Sbrian struct arpreq arpreq; 2086735Samurai 20931962Sbrian memset(&arpreq, '\0', sizeof arpreq); 21028679Sbrian SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 21136285Sbrian ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 21236285Sbrian if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) { 21337019Sbrian log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n", 21437019Sbrian strerror(errno)); 21528679Sbrian return 0; 21628679Sbrian } 21728679Sbrian return 1; 2186735Samurai} 2196735Samurai 22028679Sbrian#endif /* RTM_VERSION */ 2216735Samurai 22228679Sbrian 2236735Samurai/* 22480730Sbrian * arp_EtherAddr - get the hardware address of an interface on the 2256735Samurai * the same subnet as ipaddr. 2266735Samurai */ 2276735Samurai 22836285Sbrianint 22980730Sbrianarp_EtherAddr(int s, struct in_addr ipaddr, struct sockaddr_dl *hwaddr, 23080730Sbrian int verbose) 2316735Samurai{ 23258032Sbrian int mib[6], skip; 23332721Sbrian size_t needed; 23432721Sbrian char *buf, *ptr, *end; 23532721Sbrian struct if_msghdr *ifm; 23632721Sbrian struct ifa_msghdr *ifam; 23732616Sbrian struct sockaddr_dl *dl; 23858032Sbrian struct sockaddr *sa[RTAX_MAX]; 2396735Samurai 24032616Sbrian mib[0] = CTL_NET; 24132616Sbrian mib[1] = PF_ROUTE; 24232616Sbrian mib[2] = 0; 24332616Sbrian mib[3] = 0; 24432721Sbrian mib[4] = NET_RT_IFLIST; 24532616Sbrian mib[5] = 0; 24632721Sbrian 24732616Sbrian if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { 24880730Sbrian log_Printf(LogERROR, "arp_EtherAddr: sysctl: estimate: %s\n", 24932723Sbrian strerror(errno)); 25032616Sbrian return 0; 25128679Sbrian } 25232721Sbrian 25332721Sbrian if ((buf = malloc(needed)) == NULL) 25428679Sbrian return 0; 25532721Sbrian 25632721Sbrian if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 25732721Sbrian free(buf); 25832616Sbrian return 0; 25932616Sbrian } 26032721Sbrian end = buf + needed; 2616735Samurai 26232721Sbrian ptr = buf; 26332721Sbrian while (ptr < end) { 26432721Sbrian ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ 26532721Sbrian if (ifm->ifm_type != RTM_IFINFO) 26632721Sbrian break; 26732721Sbrian dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ 26832721Sbrian skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | 26932721Sbrian IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); 27032721Sbrian ptr += ifm->ifm_msglen; /* First ifa_msghdr */ 27132721Sbrian while (ptr < end) { 27232721Sbrian ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ 27332721Sbrian if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ 27432721Sbrian break; 27532721Sbrian ptr += ifam->ifam_msglen; 27632721Sbrian if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != 27732721Sbrian (RTA_NETMASK|RTA_IFA)) 27832721Sbrian continue; 27932721Sbrian /* Found a candidate. Do the addresses match ? */ 28036285Sbrian if (log_IsKept(LogDEBUG) && 28132721Sbrian ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) 28236285Sbrian log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", 28332721Sbrian dl->sdl_nlen, dl->sdl_data); 28458032Sbrian 28558032Sbrian iface_ParseHdr(ifam, sa); 28658032Sbrian 28758032Sbrian if (sa[RTAX_IFA]->sa_family == AF_INET) { 28858032Sbrian struct sockaddr_in *ifa, *netmask; 28958032Sbrian 29058032Sbrian ifa = (struct sockaddr_in *)sa[RTAX_IFA]; 29158032Sbrian netmask = (struct sockaddr_in *)sa[RTAX_NETMASK]; 29258032Sbrian 29358032Sbrian if (log_IsKept(LogDEBUG)) { 29458032Sbrian char a[16]; 29558032Sbrian 29658032Sbrian strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1); 29758032Sbrian a[sizeof a - 1] = '\0'; 29858032Sbrian log_Printf(LogDEBUG, "Check addr %s, mask %s\n", 29958032Sbrian inet_ntoa(ifa->sin_addr), a); 30032616Sbrian } 30158032Sbrian 30258032Sbrian if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) == 30358032Sbrian (ipaddr.s_addr & netmask->sin_addr.s_addr)) { 30480730Sbrian log_Printf(verbose ? LogPHASE : LogDEBUG, 30580730Sbrian "Found interface %.*s for %s\n", dl->sdl_alen, 30680730Sbrian dl->sdl_data, inet_ntoa(ipaddr)); 30758032Sbrian memcpy(hwaddr, dl, dl->sdl_len); 30858032Sbrian free(buf); 30958032Sbrian return 1; 31032721Sbrian } 31132616Sbrian } 3126735Samurai } 31328679Sbrian } 31432721Sbrian free(buf); 31532721Sbrian 31628679Sbrian return 0; 3176735Samurai} 318