arp.c revision 89420
176479Swpaul/* 276479Swpaul * sys-bsd.c - System-dependent procedures for setting up 376479Swpaul * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.) 476479Swpaul * 576479Swpaul * Copyright (c) 1989 Carnegie Mellon University. 676479Swpaul * All rights reserved. 776479Swpaul * 876479Swpaul * Redistribution and use in source and binary forms are permitted 976479Swpaul * provided that the above copyright notice and this paragraph are 1076479Swpaul * duplicated in all such forms and that any documentation, 1176479Swpaul * advertising materials, and other materials related to such 1276479Swpaul * distribution and use acknowledge that the software was developed 1376479Swpaul * by Carnegie Mellon University. The name of the 1476479Swpaul * University may not be used to endorse or promote products derived 1576479Swpaul * from this software without specific prior written permission. 1676479Swpaul * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 1776479Swpaul * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 1876479Swpaul * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 1976479Swpaul * 2076479Swpaul * $FreeBSD: head/usr.sbin/ppp/arp.c 89420 2002-01-16 13:15:47Z brian $ 2176479Swpaul * 2276479Swpaul */ 2376479Swpaul 2476479Swpaul/* 2576479Swpaul * TODO: 2676479Swpaul */ 2776479Swpaul 2876479Swpaul#include <sys/param.h> 2976479Swpaul#include <sys/socket.h> 3076479Swpaul#include <net/if.h> 3176479Swpaul#include <net/route.h> 3276479Swpaul#include <net/if_dl.h> 3376479Swpaul#include <netinet/in.h> 3476479Swpaul#include <netinet/if_ether.h> 3576479Swpaul#include <arpa/inet.h> 3676479Swpaul#include <netinet/in_systm.h> 3776479Swpaul#include <netinet/ip.h> 3876479Swpaul#include <sys/un.h> 3976479Swpaul 4076479Swpaul#include <errno.h> 4176479Swpaul#include <stdio.h> 4276479Swpaul#include <stdlib.h> 4376479Swpaul#include <string.h> 4476479Swpaul#include <sys/sysctl.h> 4576479Swpaul#include <termios.h> 4676479Swpaul#include <unistd.h> 4776479Swpaul 4876479Swpaul#include "layer.h" 4976479Swpaul#include "mbuf.h" 5076479Swpaul#include "log.h" 5176479Swpaul#include "id.h" 5276479Swpaul#include "timer.h" 5376479Swpaul#include "fsm.h" 5476479Swpaul#include "defs.h" 5576479Swpaul#include "iplist.h" 5676479Swpaul#include "throughput.h" 5776479Swpaul#include "slcompress.h" 5876479Swpaul#include "lqr.h" 5976479Swpaul#include "hdlc.h" 6076479Swpaul#include "ncpaddr.h" 6176479Swpaul#include "ipcp.h" 6276479Swpaul#include "ipv6cp.h" 6376479Swpaul#include "descriptor.h" 6476479Swpaul#include "lcp.h" 6576479Swpaul#include "ccp.h" 6676479Swpaul#include "link.h" 6776479Swpaul#include "mp.h" 6876479Swpaul#include "ncp.h" 6976479Swpaul#include "filter.h" 7076479Swpaul#ifndef NORADIUS 7176479Swpaul#include "radius.h" 7278323Swpaul#endif 7378323Swpaul#include "bundle.h" 7478323Swpaul#include "iface.h" 7578323Swpaul#include "arp.h" 7678323Swpaul 7778323Swpaul/* 7878323Swpaul * SET_SA_FAMILY - set the sa_family field of a struct sockaddr, 7978323Swpaul * if it exists. 8078323Swpaul */ 8178323Swpaul#define SET_SA_FAMILY(addr, family) \ 8278323Swpaul memset((char *) &(addr), '\0', sizeof(addr)); \ 8378323Swpaul addr.sa_family = (family); \ 8478323Swpaul addr.sa_len = sizeof(addr); 8578323Swpaul 8678323Swpaul 8778323Swpaul#if RTM_VERSION >= 3 8876479Swpaul 8976479Swpaul/* 9076479Swpaul * arp_SetProxy - Make a proxy ARP entry for the peer. 9176479Swpaul */ 9276479Swpaulstatic struct { 9376479Swpaul struct rt_msghdr hdr; 9476479Swpaul struct sockaddr_inarp dst; 9576479Swpaul struct sockaddr_dl hwa; 9676479Swpaul char extra[128]; 9776479Swpaul} arpmsg; 9876479Swpaul 9976479Swpaulstatic int 10076479Swpaularp_ProxySub(struct bundle *bundle, struct in_addr addr, int add, int s) 10176479Swpaul{ 10276479Swpaul int routes; 10376479Swpaul 10476479Swpaul /* 10576479Swpaul * Get the hardware address of an interface on the same subnet as our local 10676479Swpaul * address. 10776479Swpaul */ 10876479Swpaul 10976479Swpaul memset(&arpmsg, 0, sizeof arpmsg); 11076479Swpaul if (!arp_EtherAddr(s, addr, &arpmsg.hwa, 0)) { 11176479Swpaul log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n", 11276479Swpaul inet_ntoa(addr)); 11376479Swpaul return 0; 11476479Swpaul } 11576479Swpaul routes = ID0socket(AF_ROUTE, SOCK_RAW, AF_INET); 11676479Swpaul if (routes < 0) { 11776479Swpaul log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n", 11876479Swpaul strerror(errno)); 11976479Swpaul return 0; 12076479Swpaul } 12176479Swpaul arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE; 12276479Swpaul arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC; 12376479Swpaul arpmsg.hdr.rtm_version = RTM_VERSION; 12476479Swpaul arpmsg.hdr.rtm_seq = ++bundle->routing_seq; 12576479Swpaul arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY; 12676522Swpaul arpmsg.hdr.rtm_inits = RTV_EXPIRE; 12776479Swpaul arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp); 12876479Swpaul arpmsg.dst.sin_family = AF_INET; 12976479Swpaul arpmsg.dst.sin_addr.s_addr = addr.s_addr; 13076479Swpaul arpmsg.dst.sin_other = SIN_PROXY; 13176479Swpaul 13276479Swpaul arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg 13376479Swpaul + arpmsg.hwa.sdl_len; 13476479Swpaul 13576479Swpaul 13676479Swpaul if (ID0write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 && 13776479Swpaul !(!add && errno == ESRCH)) { 13876479Swpaul log_Printf(LogERROR, "%s proxy arp entry %s: %s\n", 13976479Swpaul add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno)); 14076479Swpaul close(routes); 14176479Swpaul return 0; 14276479Swpaul } 14376479Swpaul close(routes); 14476479Swpaul return 1; 14576479Swpaul} 14676479Swpaul 14776479Swpaulint 14876479Swpaularp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 14992739Salfred{ 15092739Salfred return (arp_ProxySub(bundle, addr, 1, s)); 15192739Salfred} 15276479Swpaul 15392739Salfred/* 15492739Salfred * arp_ClearProxy - Delete the proxy ARP entry for the peer. 15592739Salfred */ 15692739Salfredint 15776479Swpaularp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 15892739Salfred{ 15992739Salfred return (arp_ProxySub(bundle, addr, 0, s)); 16092739Salfred} 16192739Salfred 16292739Salfred#else /* RTM_VERSION */ 16392739Salfred 16492739Salfred/* 16592739Salfred * arp_SetProxy - Make a proxy ARP entry for the peer. 16692739Salfred */ 16792739Salfredint 16892739Salfredarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 16992739Salfred{ 17092739Salfred struct arpreq arpreq; 17192739Salfred struct { 17292739Salfred struct sockaddr_dl sdl; 17392739Salfred char space[128]; 17476479Swpaul } dls; 17592739Salfred 17692739Salfred memset(&arpreq, '\0', sizeof arpreq); 17792739Salfred 17892739Salfred /* 17992739Salfred * Get the hardware address of an interface on the same subnet as our local 18076479Swpaul * address. 18192739Salfred */ 18292739Salfred if (!arp_EtherAddr(s, addr, &dls.sdl, 1)) { 18392739Salfred log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for " 18492739Salfred "proxy ARP\n"); 18576479Swpaul return 0; 18692739Salfred } 18792739Salfred arpreq.arp_ha.sa_len = sizeof(struct sockaddr); 18892739Salfred arpreq.arp_ha.sa_family = AF_UNSPEC; 18976479Swpaul memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen); 19092739Salfred SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 19192739Salfred ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 19292739Salfred arpreq.arp_flags = ATF_PERM | ATF_PUBL; 19392739Salfred if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) { 19492739Salfred log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n", 19576479Swpaul strerror(errno)); 19676479Swpaul return 0; 19776479Swpaul } 19876479Swpaul return 1; 19976479Swpaul} 20076479Swpaul 20176479Swpaul/* 20276479Swpaul * arp_ClearProxy - Delete the proxy ARP entry for the peer. 20376479Swpaul */ 20476479Swpaulint 20576479Swpaularp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 20676479Swpaul{ 20776479Swpaul struct arpreq arpreq; 20876479Swpaul 20976479Swpaul memset(&arpreq, '\0', sizeof arpreq); 21076479Swpaul SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 21176479Swpaul ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 21276479Swpaul if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) { 21376479Swpaul log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n", 21476479Swpaul strerror(errno)); 21576479Swpaul return 0; 21676479Swpaul } 21776479Swpaul return 1; 21876479Swpaul} 21976479Swpaul 22076479Swpaul#endif /* RTM_VERSION */ 22176479Swpaul 22276479Swpaul 22376479Swpaul/* 22476479Swpaul * arp_EtherAddr - get the hardware address of an interface on the 22576479Swpaul * the same subnet as ipaddr. 22676479Swpaul */ 22776479Swpaul 22876479Swpaulint 22976479Swpaularp_EtherAddr(int s, struct in_addr ipaddr, struct sockaddr_dl *hwaddr, 23076479Swpaul int verbose) 23176479Swpaul{ 23276479Swpaul int mib[6], skip; 23376479Swpaul size_t needed; 23476479Swpaul char *buf, *ptr, *end; 23576479Swpaul struct if_msghdr *ifm; 23676479Swpaul struct ifa_msghdr *ifam; 23776479Swpaul struct sockaddr_dl *dl; 23876479Swpaul struct sockaddr *sa[RTAX_MAX]; 23976479Swpaul 24076479Swpaul mib[0] = CTL_NET; 24176479Swpaul mib[1] = PF_ROUTE; 24276479Swpaul mib[2] = 0; 24376479Swpaul mib[3] = 0; 24476479Swpaul mib[4] = NET_RT_IFLIST; 24576479Swpaul mib[5] = 0; 24676479Swpaul 24776479Swpaul if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { 24876479Swpaul log_Printf(LogERROR, "arp_EtherAddr: sysctl: estimate: %s\n", 24976479Swpaul strerror(errno)); 25076479Swpaul return 0; 25176479Swpaul } 25276479Swpaul 25376479Swpaul if ((buf = malloc(needed)) == NULL) 25476479Swpaul return 0; 25576479Swpaul 25676479Swpaul if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 25776479Swpaul free(buf); 25876479Swpaul return 0; 25976479Swpaul } 26076479Swpaul end = buf + needed; 26176479Swpaul 26276479Swpaul ptr = buf; 26376479Swpaul while (ptr < end) { 26476479Swpaul ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ 26576479Swpaul if (ifm->ifm_type != RTM_IFINFO) 26676479Swpaul break; 26776479Swpaul dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ 26876479Swpaul skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | 26976479Swpaul IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); 27076479Swpaul ptr += ifm->ifm_msglen; /* First ifa_msghdr */ 27176479Swpaul while (ptr < end) { 27276479Swpaul ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ 27376479Swpaul if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ 27476479Swpaul break; 27576479Swpaul ptr += ifam->ifam_msglen; 27676479Swpaul if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != 27776479Swpaul (RTA_NETMASK|RTA_IFA)) 27876479Swpaul continue; 27976479Swpaul /* Found a candidate. Do the addresses match ? */ 28076479Swpaul if (log_IsKept(LogDEBUG) && 28176479Swpaul ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) 28276479Swpaul log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", 28376479Swpaul dl->sdl_nlen, dl->sdl_data); 28476479Swpaul 28576479Swpaul iface_ParseHdr(ifam, sa); 28676479Swpaul 28776479Swpaul if (sa[RTAX_IFA]->sa_family == AF_INET) { 28876479Swpaul struct sockaddr_in *ifa, *netmask; 28976479Swpaul 29076479Swpaul ifa = (struct sockaddr_in *)sa[RTAX_IFA]; 29176479Swpaul netmask = (struct sockaddr_in *)sa[RTAX_NETMASK]; 29276479Swpaul 29376479Swpaul if (log_IsKept(LogDEBUG)) { 29476479Swpaul char a[16]; 29576479Swpaul 29676479Swpaul strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1); 29776479Swpaul a[sizeof a - 1] = '\0'; 29876479Swpaul log_Printf(LogDEBUG, "Check addr %s, mask %s\n", 29976479Swpaul inet_ntoa(ifa->sin_addr), a); 30076479Swpaul } 30176479Swpaul 30276479Swpaul if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) == 30376479Swpaul (ipaddr.s_addr & netmask->sin_addr.s_addr)) { 30476479Swpaul log_Printf(verbose ? LogPHASE : LogDEBUG, 30576479Swpaul "Found interface %.*s for %s\n", dl->sdl_alen, 30676479Swpaul dl->sdl_data, inet_ntoa(ipaddr)); 30776479Swpaul memcpy(hwaddr, dl, dl->sdl_len); 30876479Swpaul free(buf); 30976479Swpaul return 1; 31076479Swpaul } 31176479Swpaul } 31276479Swpaul } 31376479Swpaul } 31476479Swpaul free(buf); 31576479Swpaul 31676479Swpaul return 0; 31776479Swpaul} 31876479Swpaul