1 /* $NetBSD: if.c,v 1.21 2011/12/12 01:11:33 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/socket.h> 35 #include <sys/sysctl.h> 36 #include <sys/ioctl.h> 37 #include <net/if.h> 38 #include <net/if_types.h> 39 #include <ifaddrs.h> 40 #include <net/if_ether.h> 41 #include <net/route.h> 42 #include <net/if_dl.h> 43 #include <netinet/in.h> 44 #include <netinet/icmp6.h> 45 #include <unistd.h> 46 #include <errno.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include <syslog.h> 50 #include "rtadvd.h" 51 #include "if.h" 52 53 #ifndef RT_ROUNDUP 54 #define RT_ROUNDUP(a) \ 55 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 56 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len)) 57 #endif 58 59 struct if_msghdr **iflist; 60 int iflist_init_ok; 61 size_t ifblock_size; 62 char *ifblock; 63 64 static void get_iflist(char **buf, size_t *size); 65 static void parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, 66 size_t bufsize); 67 68 static void 69 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 70 { 71 int i; 72 73 for (i = 0; i < RTAX_MAX; i++) { 74 if (addrs & (1 << i)) { 75 rti_info[i] = sa; 76 RT_ADVANCE(sa, sa); 77 } 78 else 79 rti_info[i] = NULL; 80 } 81 } 82 83 struct sockaddr_dl * 84 if_nametosdl(const char *name) 85 { 86 struct ifaddrs *ifap, *ifa; 87 struct sockaddr_dl *sdl; 88 89 if (getifaddrs(&ifap) != 0) 90 return (NULL); 91 92 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 93 if (strcmp(ifa->ifa_name, name) != 0) 94 continue; 95 if (ifa->ifa_addr->sa_family != AF_LINK) 96 continue; 97 98 sdl = malloc(ifa->ifa_addr->sa_len); 99 if (!sdl) 100 continue; /*XXX*/ 101 102 memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len); 103 freeifaddrs(ifap); 104 return (sdl); 105 } 106 107 freeifaddrs(ifap); 108 return (NULL); 109 } 110 111 int 112 if_getmtu(const char *name) 113 { 114 struct ifaddrs *ifap, *ifa; 115 struct if_data *ifd; 116 u_long mtu = 0; 117 118 if (getifaddrs(&ifap) < 0) 119 return(0); 120 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 121 if (strcmp(ifa->ifa_name, name) == 0) { 122 ifd = ifa->ifa_data; 123 if (ifd) 124 mtu = ifd->ifi_mtu; 125 break; 126 } 127 } 128 freeifaddrs(ifap); 129 130 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 131 if (mtu == 0) { 132 struct ifreq ifr; 133 int s; 134 135 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 136 return(0); 137 138 ifr.ifr_addr.sa_family = AF_INET6; 139 strncpy(ifr.ifr_name, name, 140 sizeof(ifr.ifr_name)); 141 if (ioctl(s, SIOCGIFMTU, &ifr) < 0) { 142 close(s); 143 return(0); 144 } 145 close(s); 146 147 mtu = ifr.ifr_mtu; 148 } 149 #endif 150 151 return(mtu); 152 } 153 154 /* give interface index and its old flags, then new flags returned */ 155 int 156 if_getflags(int ifindex, int oifflags) 157 { 158 struct ifreq ifr; 159 int s; 160 161 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 162 syslog(LOG_ERR, "<%s> socket: %s", __func__, 163 strerror(errno)); 164 return (oifflags & ~IFF_UP); 165 } 166 167 if_indextoname(ifindex, ifr.ifr_name); 168 if (ioctl(s, SIOCGIFFLAGS, &ifr) < 0) { 169 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 170 __func__, ifr.ifr_name); 171 close(s); 172 return (oifflags & ~IFF_UP); 173 } 174 close(s); 175 return (ifr.ifr_flags); 176 } 177 178 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 179 int 180 lladdropt_length(struct sockaddr_dl *sdl) 181 { 182 switch (sdl->sdl_type) { 183 case IFT_ETHER: 184 case IFT_FDDI: 185 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 186 default: 187 return(0); 188 } 189 } 190 191 void 192 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 193 { 194 char *addr; 195 196 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 197 198 switch (sdl->sdl_type) { 199 case IFT_ETHER: 200 case IFT_FDDI: 201 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 202 addr = (char *)(ndopt + 1); 203 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 204 break; 205 default: 206 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 207 __func__, sdl->sdl_type); 208 exit(1); 209 } 210 211 return; 212 } 213 214 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 215 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 216 #define SDL(s) ((struct sockaddr_dl *)(s)) 217 char * 218 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 219 { 220 struct rt_msghdr *rtm; 221 struct ifa_msghdr *ifam; 222 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 223 224 *lenp = 0; 225 for (rtm = (struct rt_msghdr *)buf; 226 rtm < (struct rt_msghdr *)lim; 227 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 228 /* just for safety */ 229 if (!rtm->rtm_msglen) { 230 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 231 "(buf=%p lim=%p rtm=%p)", __func__, 232 buf, lim, rtm); 233 break; 234 } 235 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 236 continue; 237 } 238 239 switch (rtm->rtm_type) { 240 case RTM_GET: 241 case RTM_ADD: 242 case RTM_DELETE: 243 /* address related checks */ 244 sa = (struct sockaddr *)(rtm + 1); 245 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 246 if ((dst = rti_info[RTAX_DST]) == NULL || 247 dst->sa_family != AF_INET6) 248 continue; 249 250 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 251 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 252 continue; 253 254 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 255 gw->sa_family != AF_LINK) 256 continue; 257 if (ifindex && SDL(gw)->sdl_index != ifindex) 258 continue; 259 260 if (rti_info[RTAX_NETMASK] == NULL) 261 continue; 262 263 /* found */ 264 *lenp = rtm->rtm_msglen; 265 return (char *)rtm; 266 /* NOTREACHED */ 267 case RTM_NEWADDR: 268 case RTM_DELADDR: 269 ifam = (struct ifa_msghdr *)rtm; 270 271 /* address related checks */ 272 sa = (struct sockaddr *)(ifam + 1); 273 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 274 if ((ifa = rti_info[RTAX_IFA]) == NULL || 275 (ifa->sa_family != AF_INET && 276 ifa->sa_family != AF_INET6)) 277 continue; 278 279 if (ifa->sa_family == AF_INET6 && 280 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 281 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 282 continue; 283 284 if (ifindex && ifam->ifam_index != ifindex) 285 continue; 286 287 /* found */ 288 *lenp = ifam->ifam_msglen; 289 return (char *)rtm; 290 /* NOTREACHED */ 291 case RTM_IFINFO: 292 /* found */ 293 *lenp = rtm->rtm_msglen; 294 return (char *)rtm; 295 /* NOTREACHED */ 296 } 297 } 298 299 return (char *)rtm; 300 } 301 #undef FILTER_MATCH 302 303 struct in6_addr * 304 get_addr(char *buf) 305 { 306 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 307 struct sockaddr *sa, *rti_info[RTAX_MAX]; 308 309 sa = (struct sockaddr *)(rtm + 1); 310 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 311 312 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 313 } 314 315 int 316 get_rtm_ifindex(char *buf) 317 { 318 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 319 struct sockaddr *sa, *rti_info[RTAX_MAX]; 320 321 sa = (struct sockaddr *)(rtm + 1); 322 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 323 324 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 325 } 326 327 int 328 get_ifm_ifindex(char *buf) 329 { 330 struct if_msghdr *ifm = (struct if_msghdr *)buf; 331 332 return ((int)ifm->ifm_index); 333 } 334 335 int 336 get_ifam_ifindex(char *buf) 337 { 338 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 339 340 return ((int)ifam->ifam_index); 341 } 342 343 int 344 get_ifm_flags(char *buf) 345 { 346 struct if_msghdr *ifm = (struct if_msghdr *)buf; 347 348 return (ifm->ifm_flags); 349 } 350 351 int 352 get_prefixlen(char *buf) 353 { 354 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 355 struct sockaddr *sa, *rti_info[RTAX_MAX]; 356 unsigned char *p, *lim; 357 358 sa = (struct sockaddr *)(rtm + 1); 359 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 360 sa = rti_info[RTAX_NETMASK]; 361 362 p = (unsigned char *)(&SIN6(sa)->sin6_addr); 363 lim = (unsigned char *)sa + sa->sa_len; 364 return prefixlen(p, lim); 365 } 366 367 int 368 prefixlen(const unsigned char *p, const unsigned char *lim) 369 { 370 int masklen; 371 372 for (masklen = 0; p < lim; p++) { 373 switch (*p) { 374 case 0xff: 375 masklen += 8; 376 break; 377 case 0xfe: 378 masklen += 7; 379 break; 380 case 0xfc: 381 masklen += 6; 382 break; 383 case 0xf8: 384 masklen += 5; 385 break; 386 case 0xf0: 387 masklen += 4; 388 break; 389 case 0xe0: 390 masklen += 3; 391 break; 392 case 0xc0: 393 masklen += 2; 394 break; 395 case 0x80: 396 masklen += 1; 397 break; 398 case 0x00: 399 break; 400 default: 401 return(-1); 402 } 403 } 404 405 return(masklen); 406 } 407 408 int 409 rtmsg_type(char *buf) 410 { 411 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 412 413 return(rtm->rtm_type); 414 } 415 416 int 417 rtmsg_len(char *buf) 418 { 419 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 420 421 return(rtm->rtm_msglen); 422 } 423 424 int 425 ifmsg_len(char *buf) 426 { 427 struct if_msghdr *ifm = (struct if_msghdr *)buf; 428 429 return(ifm->ifm_msglen); 430 } 431 432 /* 433 * alloc buffer and get if_msghdrs block from kernel, 434 * and put them into the buffer 435 */ 436 static void 437 get_iflist(char **buf, size_t *size) 438 { 439 int mib[6]; 440 441 mib[0] = CTL_NET; 442 mib[1] = PF_ROUTE; 443 mib[2] = 0; 444 mib[3] = AF_INET6; 445 mib[4] = NET_RT_IFLIST; 446 mib[5] = 0; 447 448 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 449 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 450 __func__); 451 exit(1); 452 } 453 if ((*buf = malloc(*size)) == NULL) { 454 syslog(LOG_ERR, "<%s> malloc failed", __func__); 455 exit(1); 456 } 457 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 458 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 459 __func__); 460 exit(1); 461 } 462 return; 463 } 464 465 /* 466 * alloc buffer and parse if_msghdrs block passed as arg, 467 * and init the buffer as list of pointers ot each of the if_msghdr. 468 */ 469 static void 470 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 471 { 472 int iflentry_size, malloc_size; 473 struct if_msghdr *ifm; 474 struct ifa_msghdr *ifam; 475 char *lim; 476 477 /* 478 * Estimate least size of an iflist entry, to be obtained from kernel. 479 * Should add sizeof(sockaddr) ?? 480 */ 481 iflentry_size = sizeof(struct if_msghdr); 482 /* roughly estimate max list size of pointers to each if_msghdr */ 483 malloc_size = (bufsize/iflentry_size) * sizeof(void *); 484 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 485 syslog(LOG_ERR, "<%s> malloc failed", __func__); 486 exit(1); 487 } 488 489 lim = buf + bufsize; 490 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 491 if (ifm->ifm_msglen == 0) { 492 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 493 "(buf=%p lim=%p ifm=%p)", __func__, 494 buf, lim, ifm); 495 return; 496 } 497 498 if (ifm->ifm_type == RTM_IFINFO) { 499 (*ifmlist_p)[ifm->ifm_index] = ifm; 500 } else { 501 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 502 "expected %d, got %d\n msglen = %d\n" 503 "buf:%p, ifm:%p, lim:%p\n", 504 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 505 buf, ifm, lim); 506 exit (1); 507 } 508 for (ifam = (struct ifa_msghdr *) 509 ((char *)ifm + ifm->ifm_msglen); 510 ifam < (struct ifa_msghdr *)lim; 511 ifam = (struct ifa_msghdr *) 512 ((char *)ifam + ifam->ifam_msglen)) { 513 /* just for safety */ 514 if (!ifam->ifam_msglen) { 515 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 516 "(buf=%p lim=%p ifam=%p)", __func__, 517 buf, lim, ifam); 518 return; 519 } 520 if (ifam->ifam_type != RTM_NEWADDR) 521 break; 522 } 523 ifm = (struct if_msghdr *)ifam; 524 } 525 } 526 527 void 528 init_iflist() 529 { 530 if (ifblock) { 531 free(ifblock); 532 ifblock_size = 0; 533 } 534 if (iflist) 535 free(iflist); 536 /* get iflist block from kernel */ 537 get_iflist(&ifblock, &ifblock_size); 538 539 /* make list of pointers to each if_msghdr */ 540 parse_iflist(&iflist, ifblock, ifblock_size); 541 } 542