1 /* 2 * sys-bsd.c - System-dependent procedures for setting up 3 * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.) 4 * 5 * SPDX-License-Identifier: BSD-1-Clause 6 * 7 * Copyright (c) 1989 Carnegie Mellon University. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms are permitted 11 * provided that the above copyright notice and this paragraph are 12 * duplicated in all such forms and that any documentation, 13 * advertising materials, and other materials related to such 14 * distribution and use acknowledge that the software was developed 15 * by Carnegie Mellon University. The name of the 16 * University may not be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 20 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 21 * 22 * $FreeBSD$ 23 * 24 */ 25 26 /* 27 * TODO: 28 */ 29 30 #include <sys/param.h> 31 #include <sys/socket.h> 32 #include <net/if.h> 33 #include <net/route.h> 34 #include <net/if_dl.h> 35 #include <netinet/in.h> 36 #include <netinet/if_ether.h> 37 #include <arpa/inet.h> 38 #include <netinet/in_systm.h> 39 #include <netinet/ip.h> 40 #include <sys/un.h> 41 42 #include <errno.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <sys/sysctl.h> 47 #include <termios.h> 48 #include <unistd.h> 49 50 #include "layer.h" 51 #include "mbuf.h" 52 #include "log.h" 53 #include "id.h" 54 #include "timer.h" 55 #include "fsm.h" 56 #include "defs.h" 57 #include "iplist.h" 58 #include "throughput.h" 59 #include "slcompress.h" 60 #include "lqr.h" 61 #include "hdlc.h" 62 #include "ncpaddr.h" 63 #include "ipcp.h" 64 #include "ipv6cp.h" 65 #include "descriptor.h" 66 #include "lcp.h" 67 #include "ccp.h" 68 #include "link.h" 69 #include "mp.h" 70 #include "ncp.h" 71 #include "filter.h" 72 #ifndef NORADIUS 73 #include "radius.h" 74 #endif 75 #include "bundle.h" 76 #include "iface.h" 77 #include "arp.h" 78 79 /* 80 * SET_SA_FAMILY - set the sa_family field of a struct sockaddr, 81 * if it exists. 82 */ 83 #define SET_SA_FAMILY(addr, family) \ 84 memset((char *) &(addr), '\0', sizeof(addr)); \ 85 addr.sa_family = (family); \ 86 addr.sa_len = sizeof(addr); 87 88 89 #if RTM_VERSION >= 3 90 91 /* 92 * arp_SetProxy - Make a proxy ARP entry for the peer. 93 */ 94 static struct { 95 struct rt_msghdr hdr; 96 struct sockaddr_in dst; 97 struct sockaddr_dl hwa; 98 char extra[128]; 99 } arpmsg; 100 101 static int 102 arp_ProxySub(struct bundle *bundle, struct in_addr addr, int add) 103 { 104 int routes; 105 106 /* 107 * Get the hardware address of an interface on the same subnet as our local 108 * address. 109 */ 110 111 memset(&arpmsg, 0, sizeof arpmsg); 112 if (!arp_EtherAddr(addr, &arpmsg.hwa, 0)) { 113 log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n", 114 inet_ntoa(addr)); 115 return 0; 116 } 117 routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET); 118 if (routes < 0) { 119 log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n", 120 strerror(errno)); 121 return 0; 122 } 123 arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE; 124 arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC | RTF_LLDATA; 125 arpmsg.hdr.rtm_version = RTM_VERSION; 126 arpmsg.hdr.rtm_seq = ++bundle->routing_seq; 127 arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY; 128 arpmsg.hdr.rtm_inits = RTV_EXPIRE; 129 arpmsg.dst.sin_len = sizeof(struct sockaddr_in); 130 arpmsg.dst.sin_family = AF_INET; 131 arpmsg.dst.sin_addr.s_addr = addr.s_addr; 132 133 arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg 134 + arpmsg.hwa.sdl_len; 135 136 137 if (ID0write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 && 138 !(!add && errno == ESRCH)) { 139 log_Printf(LogERROR, "%s proxy arp entry %s: %s\n", 140 add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno)); 141 close(routes); 142 return 0; 143 } 144 close(routes); 145 return 1; 146 } 147 148 int 149 arp_SetProxy(struct bundle *bundle, struct in_addr addr) 150 { 151 return (arp_ProxySub(bundle, addr, 1)); 152 } 153 154 /* 155 * arp_ClearProxy - Delete the proxy ARP entry for the peer. 156 */ 157 int 158 arp_ClearProxy(struct bundle *bundle, struct in_addr addr) 159 { 160 return (arp_ProxySub(bundle, addr, 0)); 161 } 162 163 #else /* RTM_VERSION */ 164 165 /* 166 * arp_SetProxy - Make a proxy ARP entry for the peer. 167 */ 168 int 169 arp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) 170 { 171 struct arpreq arpreq; 172 struct { 173 struct sockaddr_dl sdl; 174 char space[128]; 175 } dls; 176 177 memset(&arpreq, '\0', sizeof arpreq); 178 179 /* 180 * Get the hardware address of an interface on the same subnet as our local 181 * address. 182 */ 183 if (!arp_EtherAddr(addr, &dls.sdl, 1)) { 184 log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for " 185 "proxy ARP\n"); 186 return 0; 187 } 188 arpreq.arp_ha.sa_len = sizeof(struct sockaddr); 189 arpreq.arp_ha.sa_family = AF_UNSPEC; 190 memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen); 191 SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 192 ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 193 arpreq.arp_flags = ATF_PERM | ATF_PUBL; 194 if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) { 195 log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n", 196 strerror(errno)); 197 return 0; 198 } 199 return 1; 200 } 201 202 /* 203 * arp_ClearProxy - Delete the proxy ARP entry for the peer. 204 */ 205 int 206 arp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) 207 { 208 struct arpreq arpreq; 209 210 memset(&arpreq, '\0', sizeof arpreq); 211 SET_SA_FAMILY(arpreq.arp_pa, AF_INET); 212 ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; 213 if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) { 214 log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n", 215 strerror(errno)); 216 return 0; 217 } 218 return 1; 219 } 220 221 #endif /* RTM_VERSION */ 222 223 224 /* 225 * arp_EtherAddr - get the hardware address of an interface on the 226 * the same subnet as ipaddr. 227 */ 228 229 int 230 arp_EtherAddr(struct in_addr ipaddr, struct sockaddr_dl *hwaddr, 231 int verbose) 232 { 233 int mib[6], skip; 234 size_t needed; 235 char *buf, *ptr, *end; 236 struct if_msghdr *ifm; 237 struct ifa_msghdr *ifam; 238 struct sockaddr_dl *dl; 239 struct sockaddr *sa[RTAX_MAX]; 240 241 mib[0] = CTL_NET; 242 mib[1] = PF_ROUTE; 243 mib[2] = 0; 244 mib[3] = 0; 245 mib[4] = NET_RT_IFLIST; 246 mib[5] = 0; 247 248 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { 249 log_Printf(LogERROR, "arp_EtherAddr: sysctl: estimate: %s\n", 250 strerror(errno)); 251 return 0; 252 } 253 254 if ((buf = malloc(needed)) == NULL) 255 return 0; 256 257 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 258 free(buf); 259 return 0; 260 } 261 end = buf + needed; 262 263 ptr = buf; 264 while (ptr < end) { 265 ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ 266 if (ifm->ifm_type != RTM_IFINFO) 267 break; 268 dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ 269 skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | 270 IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); 271 ptr += ifm->ifm_msglen; /* First ifa_msghdr */ 272 while (ptr < end) { 273 ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ 274 if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ 275 break; 276 ptr += ifam->ifam_msglen; 277 if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != 278 (RTA_NETMASK|RTA_IFA)) 279 continue; 280 /* Found a candidate. Do the addresses match ? */ 281 if (log_IsKept(LogDEBUG) && 282 ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) 283 log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", 284 dl->sdl_nlen, dl->sdl_data); 285 286 iface_ParseHdr(ifam, sa); 287 288 if (sa[RTAX_IFA]->sa_family == AF_INET) { 289 struct sockaddr_in *ifa, *netmask; 290 291 ifa = (struct sockaddr_in *)sa[RTAX_IFA]; 292 netmask = (struct sockaddr_in *)sa[RTAX_NETMASK]; 293 294 if (log_IsKept(LogDEBUG)) { 295 char a[16]; 296 297 strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1); 298 a[sizeof a - 1] = '\0'; 299 log_Printf(LogDEBUG, "Check addr %s, mask %s\n", 300 inet_ntoa(ifa->sin_addr), a); 301 } 302 303 if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) == 304 (ipaddr.s_addr & netmask->sin_addr.s_addr)) { 305 log_Printf(verbose ? LogPHASE : LogDEBUG, 306 "Found interface %.*s for %s\n", dl->sdl_nlen, 307 dl->sdl_data, inet_ntoa(ipaddr)); 308 memcpy(hwaddr, dl, dl->sdl_len); 309 free(buf); 310 return 1; 311 } 312 } 313 } 314 } 315 free(buf); 316 317 return 0; 318 } 319