1 /* $NetBSD: if.c,v 1.23 2015/06/05 15:41:59 roy Exp $ */ 2 /* $KAME: if.c,v 1.36 2004/11/30 22:32:01 suz Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/param.h> 34 #include <sys/queue.h> 35 #include <sys/socket.h> 36 #include <sys/sysctl.h> 37 #include <sys/ioctl.h> 38 #include <net/if.h> 39 #include <net/if_types.h> 40 #include <ifaddrs.h> 41 #ifdef __FreeBSD__ 42 #include <net/ethernet.h> 43 #else 44 #include <net/if_ether.h> 45 #endif 46 #include <net/route.h> 47 #include <net/if_dl.h> 48 #include <netinet/in.h> 49 #include <netinet/icmp6.h> 50 #include <unistd.h> 51 #include <errno.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <syslog.h> 55 56 #include "rtadvd.h" 57 #include "if.h" 58 59 #ifndef RT_ROUNDUP 60 #define RT_ROUNDUP(a) \ 61 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 62 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len)) 63 #endif 64 65 static void 66 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 67 { 68 int i; 69 70 for (i = 0; i < RTAX_MAX; i++) { 71 if (addrs & (1 << i)) { 72 rti_info[i] = sa; 73 RT_ADVANCE(sa, sa); 74 } 75 else 76 rti_info[i] = NULL; 77 } 78 } 79 80 struct sockaddr_dl * 81 if_nametosdl(const char *name) 82 { 83 struct ifaddrs *ifap, *ifa; 84 struct sockaddr_dl *sdl; 85 86 if (getifaddrs(&ifap) != 0) 87 return (NULL); 88 89 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 90 if (strcmp(ifa->ifa_name, name) != 0) 91 continue; 92 if (ifa->ifa_addr->sa_family != AF_LINK) 93 continue; 94 95 sdl = malloc(ifa->ifa_addr->sa_len); 96 if (!sdl) 97 continue; /*XXX*/ 98 99 memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len); 100 freeifaddrs(ifap); 101 return (sdl); 102 } 103 104 freeifaddrs(ifap); 105 return (NULL); 106 } 107 108 int 109 if_getmtu(const char *name) 110 { 111 struct ifreq ifr; 112 int s, mtu; 113 114 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 115 return 0; 116 117 memset(&ifr, 0, sizeof(ifr)); 118 ifr.ifr_addr.sa_family = AF_INET6; 119 strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); 120 if (ioctl(s, SIOCGIFMTU, &ifr) != -1) 121 mtu = ifr.ifr_mtu; 122 else 123 mtu = 0; 124 close(s); 125 126 return mtu; 127 } 128 129 /* give interface index and its old flags, then new flags returned */ 130 int 131 if_getflags(int ifindex, int oifflags) 132 { 133 struct ifreq ifr; 134 int s; 135 136 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 137 syslog(LOG_ERR, "<%s> socket: %m", __func__); 138 return (oifflags & ~IFF_UP); 139 } 140 141 memset(&ifr, 0, sizeof(ifr)); 142 if_indextoname(ifindex, ifr.ifr_name); 143 if (ioctl(s, SIOCGIFFLAGS, &ifr) < 0) { 144 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 145 __func__, ifr.ifr_name); 146 close(s); 147 return (oifflags & ~IFF_UP); 148 } 149 close(s); 150 return (ifr.ifr_flags); 151 } 152 153 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 154 int 155 lladdropt_length(struct sockaddr_dl *sdl) 156 { 157 switch (sdl->sdl_type) { 158 case IFT_ETHER: 159 case IFT_FDDI: 160 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 161 default: 162 return(0); 163 } 164 } 165 166 void 167 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 168 { 169 char *addr; 170 171 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 172 173 switch (sdl->sdl_type) { 174 case IFT_ETHER: 175 case IFT_FDDI: 176 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 177 addr = (char *)(ndopt + 1); 178 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 179 break; 180 default: 181 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 182 __func__, sdl->sdl_type); 183 exit(1); 184 } 185 186 return; 187 } 188 189 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 190 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 191 #define SDL(s) ((struct sockaddr_dl *)(s)) 192 char * 193 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 194 { 195 struct rt_msghdr *rtm; 196 struct ifa_msghdr *ifam; 197 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 198 199 *lenp = 0; 200 for (rtm = (struct rt_msghdr *)buf; 201 rtm < (struct rt_msghdr *)lim; 202 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 203 /* just for safety */ 204 if (!rtm->rtm_msglen) { 205 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 206 "(buf=%p lim=%p rtm=%p)", __func__, 207 buf, lim, rtm); 208 break; 209 } 210 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 211 continue; 212 } 213 214 switch (rtm->rtm_type) { 215 case RTM_GET: 216 case RTM_ADD: 217 case RTM_DELETE: 218 /* address related checks */ 219 sa = (struct sockaddr *)(rtm + 1); 220 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 221 if ((dst = rti_info[RTAX_DST]) == NULL || 222 dst->sa_family != AF_INET6) 223 continue; 224 225 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 226 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 227 continue; 228 229 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 230 gw->sa_family != AF_LINK) 231 continue; 232 if (ifindex && SDL(gw)->sdl_index != ifindex) 233 continue; 234 235 if (rti_info[RTAX_NETMASK] == NULL) 236 continue; 237 238 /* found */ 239 *lenp = rtm->rtm_msglen; 240 return (char *)rtm; 241 /* NOTREACHED */ 242 case RTM_NEWADDR: 243 case RTM_DELADDR: 244 ifam = (struct ifa_msghdr *)rtm; 245 246 /* address related checks */ 247 sa = (struct sockaddr *)(ifam + 1); 248 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 249 if ((ifa = rti_info[RTAX_IFA]) == NULL || 250 (ifa->sa_family != AF_INET && 251 ifa->sa_family != AF_INET6)) 252 continue; 253 254 if (ifa->sa_family == AF_INET6 && 255 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 256 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 257 continue; 258 259 if (ifindex && ifam->ifam_index != ifindex) 260 continue; 261 262 /* found */ 263 *lenp = ifam->ifam_msglen; 264 return (char *)rtm; 265 /* NOTREACHED */ 266 #ifdef RTM_IFANNOUNCE 267 case RTM_IFANNOUNCE: 268 #endif 269 case RTM_IFINFO: 270 /* found */ 271 *lenp = rtm->rtm_msglen; 272 return (char *)rtm; 273 /* NOTREACHED */ 274 } 275 } 276 277 return (char *)rtm; 278 } 279 #undef FILTER_MATCH 280 281 struct in6_addr * 282 get_addr(char *buf) 283 { 284 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 285 struct sockaddr *sa, *rti_info[RTAX_MAX]; 286 287 sa = (struct sockaddr *)(rtm + 1); 288 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 289 290 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 291 } 292 293 int 294 get_rtm_ifindex(char *buf) 295 { 296 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 297 struct sockaddr *sa, *rti_info[RTAX_MAX]; 298 299 sa = (struct sockaddr *)(rtm + 1); 300 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 301 302 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 303 } 304 305 int 306 get_ifm_ifindex(char *buf) 307 { 308 struct if_msghdr *ifm = (struct if_msghdr *)buf; 309 310 return ((int)ifm->ifm_index); 311 } 312 313 int 314 get_ifam_ifindex(char *buf) 315 { 316 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 317 318 return ((int)ifam->ifam_index); 319 } 320 321 int 322 get_ifm_flags(char *buf) 323 { 324 struct if_msghdr *ifm = (struct if_msghdr *)buf; 325 326 return (ifm->ifm_flags); 327 } 328 329 #ifdef RTM_IFANNOUNCE 330 int 331 get_ifan_ifindex(char *buf) 332 { 333 struct if_announcemsghdr *ifan = (struct if_announcemsghdr *)buf; 334 335 return ((int)ifan->ifan_index); 336 } 337 338 int 339 get_ifan_what(char *buf) 340 { 341 struct if_announcemsghdr *ifan = (struct if_announcemsghdr *)buf; 342 343 return ((int)ifan->ifan_what); 344 } 345 #endif 346 347 int 348 get_prefixlen(char *buf) 349 { 350 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 351 struct sockaddr *sa, *rti_info[RTAX_MAX]; 352 unsigned char *p, *lim; 353 354 sa = (struct sockaddr *)(rtm + 1); 355 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 356 sa = rti_info[RTAX_NETMASK]; 357 358 p = (unsigned char *)(&SIN6(sa)->sin6_addr); 359 lim = (unsigned char *)sa + sa->sa_len; 360 return prefixlen(p, lim); 361 } 362 363 int 364 prefixlen(const unsigned char *p, const unsigned char *lim) 365 { 366 int masklen; 367 368 for (masklen = 0; p < lim; p++) { 369 switch (*p) { 370 case 0xff: 371 masklen += 8; 372 break; 373 case 0xfe: 374 masklen += 7; 375 break; 376 case 0xfc: 377 masklen += 6; 378 break; 379 case 0xf8: 380 masklen += 5; 381 break; 382 case 0xf0: 383 masklen += 4; 384 break; 385 case 0xe0: 386 masklen += 3; 387 break; 388 case 0xc0: 389 masklen += 2; 390 break; 391 case 0x80: 392 masklen += 1; 393 break; 394 case 0x00: 395 break; 396 default: 397 return(-1); 398 } 399 } 400 401 return(masklen); 402 } 403 404 int 405 rtmsg_type(char *buf) 406 { 407 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 408 409 return(rtm->rtm_type); 410 } 411 412 int 413 rtmsg_len(char *buf) 414 { 415 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 416 417 return(rtm->rtm_msglen); 418 } 419