arp.c revision 67912
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 67912 2000-10-30 00:15:29Z 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" 6036285Sbrian#include "ipcp.h" 6136285Sbrian#include "filter.h" 6236285Sbrian#include "descriptor.h" 6336285Sbrian#include "lcp.h" 6436285Sbrian#include "ccp.h" 6536285Sbrian#include "link.h" 6636285Sbrian#include "mp.h" 6743313Sbrian#ifndef NORADIUS 6843313Sbrian#include "radius.h" 6943313Sbrian#endif 7036285Sbrian#include "bundle.h" 7158032Sbrian#include "iface.h" 7230715Sbrian#include "arp.h" 736735Samurai 7432616Sbrian/* 756735Samurai * SET_SA_FAMILY - set the sa_family field of a struct sockaddr, 766735Samurai * if it exists. 776735Samurai */ 786735Samurai#define SET_SA_FAMILY(addr, family) \ 7930715Sbrian memset((char *) &(addr), '\0', sizeof(addr)); \ 806735Samurai addr.sa_family = (family); \ 816735Samurai addr.sa_len = sizeof(addr); 826735Samurai 836735Samurai 846735Samurai#if RTM_VERSION >= 3 856735Samurai 866735Samurai/* 8736285Sbrian * arp_SetProxy - Make a proxy ARP entry for the peer. 886735Samurai */ 896735Samuraistatic struct { 9028679Sbrian struct rt_msghdr hdr; 9128679Sbrian struct sockaddr_inarp dst; 9228679Sbrian struct sockaddr_dl hwa; 9328679Sbrian char extra[128]; 9430715Sbrian} arpmsg; 956735Samurai 9640665Sbrianstatic int 9740665Sbrianarp_ProxySub(struct bundle *bundle, struct in_addr addr, int add, int s) 986735Samurai{ 9928679Sbrian int routes; 1006735Samurai 10128679Sbrian /* 10228679Sbrian * Get the hardware address of an interface on the same subnet as our local 10328679Sbrian * address. 10428679Sbrian */ 10540665Sbrian 10631962Sbrian memset(&arpmsg, 0, sizeof arpmsg); 10736285Sbrian if (!get_ether_addr(s, addr, &arpmsg.hwa)) { 10840665Sbrian log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n", 10940665Sbrian inet_ntoa(addr)); 11028679Sbrian return 0; 11128679Sbrian } 11231061Sbrian routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET); 11331061Sbrian if (routes < 0) { 11436285Sbrian log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n", 11528679Sbrian strerror(errno)); 11628679Sbrian return 0; 11728679Sbrian } 11840665Sbrian arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE; 11928679Sbrian arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC; 12028679Sbrian arpmsg.hdr.rtm_version = RTM_VERSION; 12136285Sbrian arpmsg.hdr.rtm_seq = ++bundle->routing_seq; 12228679Sbrian arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY; 12328679Sbrian arpmsg.hdr.rtm_inits = RTV_EXPIRE; 12428679Sbrian arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp); 12528679Sbrian arpmsg.dst.sin_family = AF_INET; 12636285Sbrian arpmsg.dst.sin_addr.s_addr = addr.s_addr; 12728679Sbrian arpmsg.dst.sin_other = SIN_PROXY; 1286735Samurai 12928679Sbrian arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg 13028679Sbrian + arpmsg.hwa.sdl_len; 13140665Sbrian 13240665Sbrian 13340665Sbrian if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 && 13440665Sbrian !(!add && errno == ESRCH)) { 13540665Sbrian log_Printf(LogERROR, "%s proxy arp entry %s: %s\n", 13640665Sbrian add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno)); 1376735Samurai close(routes); 13828679Sbrian return 0; 13928679Sbrian } 14028679Sbrian close(routes); 14128679Sbrian return 1; 1426735Samurai} 1436735Samurai 14440665Sbrianint 14540665Sbrianarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 14640665Sbrian{ 14740665Sbrian 14840665Sbrian return (arp_ProxySub(bundle, addr, 1, s)); 14940665Sbrian} 15040665Sbrian 1516735Samurai/* 15236285Sbrian * arp_ClearProxy - Delete the proxy ARP entry for the peer. 1536735Samurai */ 1546735Samuraiint 15536285Sbrianarp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 1566735Samurai{ 1576735Samurai 15840665Sbrian return (arp_ProxySub(bundle, addr, 0, s)); 1596735Samurai} 1606735Samurai 16128679Sbrian#else /* RTM_VERSION */ 1626735Samurai 1636735Samurai/* 16436285Sbrian * arp_SetProxy - Make a proxy ARP entry for the peer. 1656735Samurai */ 1666735Samuraiint 16736285Sbrianarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 1686735Samurai{ 16928679Sbrian struct arpreq arpreq; 17028679Sbrian struct { 17128679Sbrian struct sockaddr_dl sdl; 17228679Sbrian char space[128]; 17328679Sbrian } dls; 1746735Samurai 17531962Sbrian memset(&arpreq, '\0', sizeof arpreq); 1766735Samurai 17728679Sbrian /* 17828679Sbrian * Get the hardware address of an interface on the same subnet as our local 17928679Sbrian * address. 18028679Sbrian */ 18136285Sbrian if (!get_ether_addr(s, addr, &dls.sdl)) { 18267912Sbrian log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for " 18367912Sbrian "proxy ARP\n"); 18428679Sbrian return 0; 18528679Sbrian } 18628679Sbrian arpreq.arp_ha.sa_len = sizeof(struct sockaddr); 18728679Sbrian arpreq.arp_ha.sa_family = AF_UNSPEC; 18830715Sbrian memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen); 18928679Sbrian SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 19036285Sbrian ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 19128679Sbrian arpreq.arp_flags = ATF_PERM | ATF_PUBL; 19236285Sbrian if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) { 19337019Sbrian log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n", 19437019Sbrian strerror(errno)); 19528679Sbrian return 0; 19628679Sbrian } 19728679Sbrian return 1; 1986735Samurai} 1996735Samurai 2006735Samurai/* 20136285Sbrian * arp_ClearProxy - Delete the proxy ARP entry for the peer. 2026735Samurai */ 2036735Samuraiint 20436285Sbrianarp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 2056735Samurai{ 20628679Sbrian struct arpreq arpreq; 2076735Samurai 20831962Sbrian memset(&arpreq, '\0', sizeof arpreq); 20928679Sbrian SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 21036285Sbrian ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 21136285Sbrian if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) { 21237019Sbrian log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n", 21337019Sbrian strerror(errno)); 21428679Sbrian return 0; 21528679Sbrian } 21628679Sbrian return 1; 2176735Samurai} 2186735Samurai 21928679Sbrian#endif /* RTM_VERSION */ 2206735Samurai 22128679Sbrian 2226735Samurai/* 2236735Samurai * get_ether_addr - get the hardware address of an interface on the 2246735Samurai * the same subnet as ipaddr. 2256735Samurai */ 2266735Samurai 22736285Sbrianint 22832616Sbrianget_ether_addr(int s, struct in_addr ipaddr, struct sockaddr_dl *hwaddr) 2296735Samurai{ 23058032Sbrian int mib[6], skip; 23132721Sbrian size_t needed; 23232721Sbrian char *buf, *ptr, *end; 23332721Sbrian struct if_msghdr *ifm; 23432721Sbrian struct ifa_msghdr *ifam; 23532616Sbrian struct sockaddr_dl *dl; 23658032Sbrian struct sockaddr *sa[RTAX_MAX]; 2376735Samurai 23832616Sbrian mib[0] = CTL_NET; 23932616Sbrian mib[1] = PF_ROUTE; 24032616Sbrian mib[2] = 0; 24132616Sbrian mib[3] = 0; 24232721Sbrian mib[4] = NET_RT_IFLIST; 24332616Sbrian mib[5] = 0; 24432721Sbrian 24532616Sbrian if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { 24636285Sbrian log_Printf(LogERROR, "get_ether_addr: sysctl: estimate: %s\n", 24732723Sbrian strerror(errno)); 24832616Sbrian return 0; 24928679Sbrian } 25032721Sbrian 25132721Sbrian if ((buf = malloc(needed)) == NULL) 25228679Sbrian return 0; 25332721Sbrian 25432721Sbrian if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 25532721Sbrian free(buf); 25632616Sbrian return 0; 25732616Sbrian } 25832721Sbrian end = buf + needed; 2596735Samurai 26032721Sbrian ptr = buf; 26132721Sbrian while (ptr < end) { 26232721Sbrian ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ 26332721Sbrian if (ifm->ifm_type != RTM_IFINFO) 26432721Sbrian break; 26532721Sbrian dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ 26632721Sbrian skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | 26732721Sbrian IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); 26832721Sbrian ptr += ifm->ifm_msglen; /* First ifa_msghdr */ 26932721Sbrian while (ptr < end) { 27032721Sbrian ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ 27132721Sbrian if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ 27232721Sbrian break; 27332721Sbrian ptr += ifam->ifam_msglen; 27432721Sbrian if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != 27532721Sbrian (RTA_NETMASK|RTA_IFA)) 27632721Sbrian continue; 27732721Sbrian /* Found a candidate. Do the addresses match ? */ 27836285Sbrian if (log_IsKept(LogDEBUG) && 27932721Sbrian ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) 28036285Sbrian log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", 28132721Sbrian dl->sdl_nlen, dl->sdl_data); 28258032Sbrian 28358032Sbrian iface_ParseHdr(ifam, sa); 28458032Sbrian 28558032Sbrian if (sa[RTAX_IFA]->sa_family == AF_INET) { 28658032Sbrian struct sockaddr_in *ifa, *netmask; 28758032Sbrian 28858032Sbrian ifa = (struct sockaddr_in *)sa[RTAX_IFA]; 28958032Sbrian netmask = (struct sockaddr_in *)sa[RTAX_NETMASK]; 29058032Sbrian 29158032Sbrian if (log_IsKept(LogDEBUG)) { 29258032Sbrian char a[16]; 29358032Sbrian 29458032Sbrian strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1); 29558032Sbrian a[sizeof a - 1] = '\0'; 29658032Sbrian log_Printf(LogDEBUG, "Check addr %s, mask %s\n", 29758032Sbrian inet_ntoa(ifa->sin_addr), a); 29832616Sbrian } 29958032Sbrian 30058032Sbrian if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) == 30158032Sbrian (ipaddr.s_addr & netmask->sin_addr.s_addr)) { 30258032Sbrian log_Printf(LogPHASE, "Found interface %.*s for %s\n", 30358032Sbrian dl->sdl_alen, dl->sdl_data, inet_ntoa(ipaddr)); 30458032Sbrian memcpy(hwaddr, dl, dl->sdl_len); 30558032Sbrian free(buf); 30658032Sbrian return 1; 30732721Sbrian } 30832616Sbrian } 3096735Samurai } 31028679Sbrian } 31132721Sbrian free(buf); 31232721Sbrian 31328679Sbrian return 0; 3146735Samurai} 315