arp.c revision 51517
1131823Sharti/* 2156678Sharti * sys-bsd.c - System-dependent procedures for setting up 3156678Sharti * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.) 4156678Sharti * 5131823Sharti * Copyright (c) 1989 Carnegie Mellon University. 6131823Sharti * All rights reserved. 7131823Sharti * 8131823Sharti * Redistribution and use in source and binary forms are permitted 9131823Sharti * provided that the above copyright notice and this paragraph are 10131823Sharti * duplicated in all such forms and that any documentation, 11131823Sharti * advertising materials, and other materials related to such 12131823Sharti * distribution and use acknowledge that the software was developed 13131823Sharti * by Carnegie Mellon University. The name of the 14131823Sharti * University may not be used to endorse or promote products derived 15131823Sharti * from this software without specific prior written permission. 16131823Sharti * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17131823Sharti * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18131823Sharti * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19131823Sharti * 20131823Sharti * $FreeBSD: head/usr.sbin/ppp/arp.c 51517 1999-09-21 19:37:00Z brian $ 21131823Sharti * 22131823Sharti */ 23131823Sharti 24131823Sharti/* 25131823Sharti * TODO: 26131823Sharti */ 27131823Sharti 28131823Sharti#include <sys/param.h> 29131823Sharti#include <sys/socket.h> 30208483Suqs#include <net/if.h> 31131823Sharti#include <net/route.h> 32156678Sharti#include <net/if_dl.h> 33131823Sharti#include <netinet/in.h> 34156678Sharti#include <netinet/if_ether.h> 35146532Sharti#include <arpa/inet.h> 36131823Sharti#include <netinet/in_systm.h> 37131823Sharti#include <netinet/ip.h> 38131823Sharti#include <sys/un.h> 39131823Sharti 40131823Sharti#include <errno.h> 41131823Sharti#include <stdio.h> 42131823Sharti#include <stdlib.h> 43131823Sharti#include <string.h> 44131823Sharti#include <sys/sysctl.h> 45131823Sharti#include <termios.h> 46131823Sharti#include <unistd.h> 47131823Sharti 48131823Sharti#include "layer.h" 49131823Sharti#include "mbuf.h" 50131823Sharti#include "log.h" 51131823Sharti#include "id.h" 52131823Sharti#include "timer.h" 53131823Sharti#include "fsm.h" 54131823Sharti#include "defs.h" 55131823Sharti#include "iplist.h" 56131823Sharti#include "throughput.h" 57131823Sharti#include "slcompress.h" 58131823Sharti#include "lqr.h" 59131823Sharti#include "hdlc.h" 60131823Sharti#include "ipcp.h" 61131823Sharti#include "filter.h" 62131823Sharti#include "descriptor.h" 63131823Sharti#include "lcp.h" 64131823Sharti#include "ccp.h" 65131823Sharti#include "link.h" 66131823Sharti#include "mp.h" 67131823Sharti#ifndef NORADIUS 68131823Sharti#include "radius.h" 69131823Sharti#endif 70131823Sharti#include "bundle.h" 71131823Sharti#include "arp.h" 72131823Sharti 73131823Sharti/* 74131823Sharti * SET_SA_FAMILY - set the sa_family field of a struct sockaddr, 75131823Sharti * if it exists. 76131823Sharti */ 77131823Sharti#define SET_SA_FAMILY(addr, family) \ 78131823Sharti memset((char *) &(addr), '\0', sizeof(addr)); \ 79131823Sharti addr.sa_family = (family); \ 80131823Sharti addr.sa_len = sizeof(addr); 81131823Sharti 82131823Sharti 83131823Sharti#if RTM_VERSION >= 3 84131823Sharti 85131823Sharti/* 86131823Sharti * arp_SetProxy - Make a proxy ARP entry for the peer. 87131823Sharti */ 88131823Shartistatic struct { 89131823Sharti struct rt_msghdr hdr; 90131823Sharti struct sockaddr_inarp dst; 91131823Sharti struct sockaddr_dl hwa; 92131823Sharti char extra[128]; 93131823Sharti} arpmsg; 94156678Sharti 95156678Shartistatic int 96156678Shartiarp_ProxySub(struct bundle *bundle, struct in_addr addr, int add, int s) 97156678Sharti{ 98131823Sharti int routes; 99131823Sharti 100131823Sharti /* 101131823Sharti * Get the hardware address of an interface on the same subnet as our local 102131823Sharti * address. 103131823Sharti */ 104131823Sharti 105131823Sharti memset(&arpmsg, 0, sizeof arpmsg); 106131823Sharti if (!get_ether_addr(s, addr, &arpmsg.hwa)) { 107131823Sharti log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n", 108131823Sharti inet_ntoa(addr)); 109131823Sharti return 0; 110131823Sharti } 111156678Sharti routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET); 112156678Sharti if (routes < 0) { 113156678Sharti log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n", 114156678Sharti strerror(errno)); 115146532Sharti return 0; 116131823Sharti } 117131823Sharti arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE; 118131823Sharti arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC; 119131823Sharti arpmsg.hdr.rtm_version = RTM_VERSION; 120131823Sharti arpmsg.hdr.rtm_seq = ++bundle->routing_seq; 121131823Sharti arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY; 122131823Sharti arpmsg.hdr.rtm_inits = RTV_EXPIRE; 123131823Sharti arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp); 124131823Sharti arpmsg.dst.sin_family = AF_INET; 125131823Sharti arpmsg.dst.sin_addr.s_addr = addr.s_addr; 126131823Sharti arpmsg.dst.sin_other = SIN_PROXY; 127131823Sharti 128131823Sharti arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg 129131823Sharti + arpmsg.hwa.sdl_len; 130131823Sharti 131131823Sharti 132156678Sharti if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 && 133131823Sharti !(!add && errno == ESRCH)) { 134131823Sharti log_Printf(LogERROR, "%s proxy arp entry %s: %s\n", 135131823Sharti add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno)); 136131823Sharti close(routes); 137131823Sharti return 0; 138131823Sharti } 139131823Sharti close(routes); 140131823Sharti return 1; 141131823Sharti} 142131823Sharti 143131823Shartiint 144131823Shartiarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 145131823Sharti{ 146131823Sharti 147131823Sharti return (arp_ProxySub(bundle, addr, 1, s)); 148131823Sharti} 149131823Sharti 150131823Sharti/* 151156678Sharti * arp_ClearProxy - Delete the proxy ARP entry for the peer. 152131823Sharti */ 153131823Shartiint 154131823Shartiarp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 155131823Sharti{ 156131823Sharti 157131823Sharti return (arp_ProxySub(bundle, addr, 0, s)); 158131823Sharti} 159131823Sharti 160131823Sharti#else /* RTM_VERSION */ 161156678Sharti 162156678Sharti/* 163131823Sharti * arp_SetProxy - Make a proxy ARP entry for the peer. 164131823Sharti */ 165131823Shartiint 166156678Shartiarp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 167156678Sharti{ 168131823Sharti struct arpreq arpreq; 169131823Sharti struct { 170131823Sharti struct sockaddr_dl sdl; 171131823Sharti char space[128]; 172131823Sharti } dls; 173131823Sharti 174131823Sharti memset(&arpreq, '\0', sizeof arpreq); 175146532Sharti 176131823Sharti /* 177131823Sharti * Get the hardware address of an interface on the same subnet as our local 178131823Sharti * address. 179131823Sharti */ 180131823Sharti if (!get_ether_addr(s, addr, &dls.sdl)) { 181156678Sharti log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for proxy ARP\n"); 182156678Sharti return 0; 183156678Sharti } 184156678Sharti arpreq.arp_ha.sa_len = sizeof(struct sockaddr); 185156678Sharti arpreq.arp_ha.sa_family = AF_UNSPEC; 186156678Sharti memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen); 187131823Sharti SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 188131823Sharti ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 189131823Sharti arpreq.arp_flags = ATF_PERM | ATF_PUBL; 190131823Sharti if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) { 191131823Sharti log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n", 192131823Sharti strerror(errno)); 193131823Sharti return 0; 194131823Sharti } 195131823Sharti return 1; 196131823Sharti} 197156678Sharti 198156678Sharti/* 199131823Sharti * arp_ClearProxy - Delete the proxy ARP entry for the peer. 200131823Sharti */ 201131823Shartiint 202131823Shartiarp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 203156678Sharti{ 204156678Sharti struct arpreq arpreq; 205131823Sharti 206131823Sharti memset(&arpreq, '\0', sizeof arpreq); 207131823Sharti SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 208131823Sharti ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 209131823Sharti if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) { 210131823Sharti log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n", 211131823Sharti strerror(errno)); 212131823Sharti return 0; 213131823Sharti } 214131823Sharti return 1; 215131823Sharti} 216131823Sharti 217131823Sharti#endif /* RTM_VERSION */ 218131823Sharti 219131823Sharti 220131823Sharti/* 221131823Sharti * get_ether_addr - get the hardware address of an interface on the 222131823Sharti * the same subnet as ipaddr. 223131823Sharti */ 224131823Sharti 225131823Shartiint 226131823Shartiget_ether_addr(int s, struct in_addr ipaddr, struct sockaddr_dl *hwaddr) 227131823Sharti{ 228131823Sharti int mib[6], sa_len, skip, b; 229131823Sharti size_t needed; 230131823Sharti char *buf, *ptr, *end; 231131823Sharti struct if_msghdr *ifm; 232131823Sharti struct ifa_msghdr *ifam; 233146532Sharti struct sockaddr *sa; 234131823Sharti struct sockaddr_dl *dl; 235131823Sharti struct sockaddr_in *ifa, *mask; 236131823Sharti 237131823Sharti mib[0] = CTL_NET; 238156678Sharti mib[1] = PF_ROUTE; 239156678Sharti mib[2] = 0; 240156678Sharti mib[3] = 0; 241156678Sharti mib[4] = NET_RT_IFLIST; 242156678Sharti mib[5] = 0; 243156678Sharti 244131823Sharti if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { 245131823Sharti log_Printf(LogERROR, "get_ether_addr: sysctl: estimate: %s\n", 246131823Sharti strerror(errno)); 247131823Sharti return 0; 248131823Sharti } 249131823Sharti 250156678Sharti if ((buf = malloc(needed)) == NULL) 251156678Sharti return 0; 252131823Sharti 253156678Sharti if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 254156678Sharti free(buf); 255131823Sharti return 0; 256131823Sharti } 257131823Sharti end = buf + needed; 258131823Sharti 259131823Sharti ptr = buf; 260131823Sharti while (ptr < end) { 261131823Sharti ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ 262131823Sharti if (ifm->ifm_type != RTM_IFINFO) 263146532Sharti break; 264131823Sharti dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ 265208483Suqs skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | 266 IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); 267 ptr += ifm->ifm_msglen; /* First ifa_msghdr */ 268 while (ptr < end) { 269 ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ 270 if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ 271 break; 272 sa = (struct sockaddr *)(ifam+1); /* pile of sa's at end */ 273 ptr += ifam->ifam_msglen; 274 if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != 275 (RTA_NETMASK|RTA_IFA)) 276 continue; 277 /* Found a candidate. Do the addresses match ? */ 278 if (log_IsKept(LogDEBUG) && 279 ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) 280 log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", 281 dl->sdl_nlen, dl->sdl_data); 282 b = 1; 283 ifa = mask = NULL; 284 while (b < (RTA_NETMASK|RTA_IFA) && sa < (struct sockaddr *)ptr) { 285 switch (b) { 286 case RTA_IFA: 287 ifa = (struct sockaddr_in *)sa; 288 break; 289 case RTA_NETMASK: 290 /* 291 * Careful here ! this sockaddr doesn't have sa_family set to 292 * AF_INET, and is only 8 bytes big ! I have no idea why ! 293 */ 294 mask = (struct sockaddr_in *)sa; 295 break; 296 } 297 if (ifam->ifam_addrs & b) { 298#define ALN sizeof(ifa->sin_addr.s_addr) 299 sa_len = sa->sa_len > 0 ? ((sa->sa_len-1)|(ALN-1))+1 : ALN; 300 sa = (struct sockaddr *)((char *)sa + sa_len); 301 } 302 b <<= 1; 303 } 304 if (log_IsKept(LogDEBUG)) { 305 char a[16]; 306 strncpy(a, inet_ntoa(mask->sin_addr), sizeof a - 1); 307 a[sizeof a - 1] = '\0'; 308 log_Printf(LogDEBUG, "Check addr %s, mask %s\n", 309 inet_ntoa(ifa->sin_addr), a); 310 } 311 if (ifa->sin_family == AF_INET && 312 (ifa->sin_addr.s_addr & mask->sin_addr.s_addr) == 313 (ipaddr.s_addr & mask->sin_addr.s_addr)) { 314 log_Printf(LogPHASE, "Found interface %.*s for %s\n", 315 dl->sdl_alen, dl->sdl_data, inet_ntoa(ipaddr)); 316 memcpy(hwaddr, dl, dl->sdl_len); 317 free(buf); 318 return 1; 319 } 320 } 321 } 322 free(buf); 323 324 return 0; 325} 326