1 /* $NetBSD: if.c,v 1.18 2006/03/05 23:47:08 rpaulo 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 #define ROUNDUP(a, size) \ 54 (((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a)) 55 56 #define NEXT_SA(ap) (ap) = (struct sockaddr *) \ 57 ((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\ 58 sizeof(u_long)) :\ 59 sizeof(u_long))) 60 61 struct if_msghdr **iflist; 62 int iflist_init_ok; 63 size_t ifblock_size; 64 char *ifblock; 65 66 static void get_iflist __P((char **buf, size_t *size)); 67 static void parse_iflist __P((struct if_msghdr ***ifmlist_p, char *buf, 68 size_t bufsize)); 69 70 static void 71 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 72 { 73 int i; 74 75 for (i = 0; i < RTAX_MAX; i++) { 76 if (addrs & (1 << i)) { 77 rti_info[i] = sa; 78 NEXT_SA(sa); 79 } 80 else 81 rti_info[i] = NULL; 82 } 83 } 84 85 struct sockaddr_dl * 86 if_nametosdl(char *name) 87 { 88 struct ifaddrs *ifap, *ifa; 89 struct sockaddr_dl *sdl; 90 91 if (getifaddrs(&ifap) != 0) 92 return (NULL); 93 94 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 95 if (strcmp(ifa->ifa_name, name) != 0) 96 continue; 97 if (ifa->ifa_addr->sa_family != AF_LINK) 98 continue; 99 100 sdl = malloc(ifa->ifa_addr->sa_len); 101 if (!sdl) 102 continue; /*XXX*/ 103 104 memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len); 105 freeifaddrs(ifap); 106 return (sdl); 107 } 108 109 freeifaddrs(ifap); 110 return (NULL); 111 } 112 113 int 114 if_getmtu(char *name) 115 { 116 struct ifaddrs *ifap, *ifa; 117 struct if_data *ifd; 118 u_long mtu = 0; 119 120 if (getifaddrs(&ifap) < 0) 121 return(0); 122 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 123 if (strcmp(ifa->ifa_name, name) == 0) { 124 ifd = ifa->ifa_data; 125 if (ifd) 126 mtu = ifd->ifi_mtu; 127 break; 128 } 129 } 130 freeifaddrs(ifap); 131 132 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 133 if (mtu == 0) { 134 struct ifreq ifr; 135 int s; 136 137 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 138 return(0); 139 140 ifr.ifr_addr.sa_family = AF_INET6; 141 strncpy(ifr.ifr_name, name, 142 sizeof(ifr.ifr_name)); 143 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 144 close(s); 145 return(0); 146 } 147 close(s); 148 149 mtu = ifr.ifr_mtu; 150 } 151 #endif 152 153 return(mtu); 154 } 155 156 /* give interface index and its old flags, then new flags returned */ 157 int 158 if_getflags(int ifindex, int oifflags) 159 { 160 struct ifreq ifr; 161 int s; 162 163 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 164 syslog(LOG_ERR, "<%s> socket: %s", __func__, 165 strerror(errno)); 166 return (oifflags & ~IFF_UP); 167 } 168 169 if_indextoname(ifindex, ifr.ifr_name); 170 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 171 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 172 __func__, ifr.ifr_name); 173 close(s); 174 return (oifflags & ~IFF_UP); 175 } 176 close(s); 177 return (ifr.ifr_flags); 178 } 179 180 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 181 int 182 lladdropt_length(struct sockaddr_dl *sdl) 183 { 184 switch (sdl->sdl_type) { 185 case IFT_ETHER: 186 case IFT_FDDI: 187 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 188 default: 189 return(0); 190 } 191 } 192 193 void 194 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 195 { 196 char *addr; 197 198 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 199 200 switch (sdl->sdl_type) { 201 case IFT_ETHER: 202 case IFT_FDDI: 203 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 204 addr = (char *)(ndopt + 1); 205 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 206 break; 207 default: 208 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 209 __func__, sdl->sdl_type); 210 exit(1); 211 } 212 213 return; 214 } 215 216 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 217 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 218 #define SDL(s) ((struct sockaddr_dl *)(s)) 219 char * 220 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 221 { 222 struct rt_msghdr *rtm; 223 struct ifa_msghdr *ifam; 224 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 225 226 *lenp = 0; 227 for (rtm = (struct rt_msghdr *)buf; 228 rtm < (struct rt_msghdr *)lim; 229 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 230 /* just for safety */ 231 if (!rtm->rtm_msglen) { 232 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 233 "(buf=%p lim=%p rtm=%p)", __func__, 234 buf, lim, rtm); 235 break; 236 } 237 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 238 continue; 239 } 240 241 switch (rtm->rtm_type) { 242 case RTM_GET: 243 case RTM_ADD: 244 case RTM_DELETE: 245 /* address related checks */ 246 sa = (struct sockaddr *)(rtm + 1); 247 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 248 if ((dst = rti_info[RTAX_DST]) == NULL || 249 dst->sa_family != AF_INET6) 250 continue; 251 252 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 253 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 254 continue; 255 256 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 257 gw->sa_family != AF_LINK) 258 continue; 259 if (ifindex && SDL(gw)->sdl_index != ifindex) 260 continue; 261 262 if (rti_info[RTAX_NETMASK] == NULL) 263 continue; 264 265 /* found */ 266 *lenp = rtm->rtm_msglen; 267 return (char *)rtm; 268 /* NOTREACHED */ 269 case RTM_NEWADDR: 270 case RTM_DELADDR: 271 ifam = (struct ifa_msghdr *)rtm; 272 273 /* address related checks */ 274 sa = (struct sockaddr *)(ifam + 1); 275 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 276 if ((ifa = rti_info[RTAX_IFA]) == NULL || 277 (ifa->sa_family != AF_INET && 278 ifa->sa_family != AF_INET6)) 279 continue; 280 281 if (ifa->sa_family == AF_INET6 && 282 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 283 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 284 continue; 285 286 if (ifindex && ifam->ifam_index != ifindex) 287 continue; 288 289 /* found */ 290 *lenp = ifam->ifam_msglen; 291 return (char *)rtm; 292 /* NOTREACHED */ 293 case RTM_IFINFO: 294 /* found */ 295 *lenp = rtm->rtm_msglen; 296 return (char *)rtm; 297 /* NOTREACHED */ 298 } 299 } 300 301 return (char *)rtm; 302 } 303 #undef FILTER_MATCH 304 305 struct in6_addr * 306 get_addr(char *buf) 307 { 308 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 309 struct sockaddr *sa, *rti_info[RTAX_MAX]; 310 311 sa = (struct sockaddr *)(rtm + 1); 312 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 313 314 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 315 } 316 317 int 318 get_rtm_ifindex(char *buf) 319 { 320 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 321 struct sockaddr *sa, *rti_info[RTAX_MAX]; 322 323 sa = (struct sockaddr *)(rtm + 1); 324 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 325 326 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 327 } 328 329 int 330 get_ifm_ifindex(char *buf) 331 { 332 struct if_msghdr *ifm = (struct if_msghdr *)buf; 333 334 return ((int)ifm->ifm_index); 335 } 336 337 int 338 get_ifam_ifindex(char *buf) 339 { 340 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 341 342 return ((int)ifam->ifam_index); 343 } 344 345 int 346 get_ifm_flags(char *buf) 347 { 348 struct if_msghdr *ifm = (struct if_msghdr *)buf; 349 350 return (ifm->ifm_flags); 351 } 352 353 int 354 get_prefixlen(char *buf) 355 { 356 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 357 struct sockaddr *sa, *rti_info[RTAX_MAX]; 358 u_char *p, *lim; 359 360 sa = (struct sockaddr *)(rtm + 1); 361 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 362 sa = rti_info[RTAX_NETMASK]; 363 364 p = (u_char *)(&SIN6(sa)->sin6_addr); 365 lim = (u_char *)sa + sa->sa_len; 366 return prefixlen(p, lim); 367 } 368 369 int 370 prefixlen(u_char *p, u_char *lim) 371 { 372 int masklen; 373 374 for (masklen = 0; p < lim; p++) { 375 switch (*p) { 376 case 0xff: 377 masklen += 8; 378 break; 379 case 0xfe: 380 masklen += 7; 381 break; 382 case 0xfc: 383 masklen += 6; 384 break; 385 case 0xf8: 386 masklen += 5; 387 break; 388 case 0xf0: 389 masklen += 4; 390 break; 391 case 0xe0: 392 masklen += 3; 393 break; 394 case 0xc0: 395 masklen += 2; 396 break; 397 case 0x80: 398 masklen += 1; 399 break; 400 case 0x00: 401 break; 402 default: 403 return(-1); 404 } 405 } 406 407 return(masklen); 408 } 409 410 int 411 rtmsg_type(char *buf) 412 { 413 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 414 415 return(rtm->rtm_type); 416 } 417 418 int 419 rtmsg_len(char *buf) 420 { 421 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 422 423 return(rtm->rtm_msglen); 424 } 425 426 int 427 ifmsg_len(char *buf) 428 { 429 struct if_msghdr *ifm = (struct if_msghdr *)buf; 430 431 return(ifm->ifm_msglen); 432 } 433 434 /* 435 * alloc buffer and get if_msghdrs block from kernel, 436 * and put them into the buffer 437 */ 438 static void 439 get_iflist(char **buf, size_t *size) 440 { 441 int mib[6]; 442 443 mib[0] = CTL_NET; 444 mib[1] = PF_ROUTE; 445 mib[2] = 0; 446 mib[3] = AF_INET6; 447 mib[4] = NET_RT_IFLIST; 448 mib[5] = 0; 449 450 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 451 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 452 __func__); 453 exit(1); 454 } 455 if ((*buf = malloc(*size)) == NULL) { 456 syslog(LOG_ERR, "<%s> malloc failed", __func__); 457 exit(1); 458 } 459 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 460 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 461 __func__); 462 exit(1); 463 } 464 return; 465 } 466 467 /* 468 * alloc buffer and parse if_msghdrs block passed as arg, 469 * and init the buffer as list of pointers ot each of the if_msghdr. 470 */ 471 static void 472 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 473 { 474 int iflentry_size, malloc_size; 475 struct if_msghdr *ifm; 476 struct ifa_msghdr *ifam; 477 char *lim; 478 479 /* 480 * Estimate least size of an iflist entry, to be obtained from kernel. 481 * Should add sizeof(sockaddr) ?? 482 */ 483 iflentry_size = sizeof(struct if_msghdr); 484 /* roughly estimate max list size of pointers to each if_msghdr */ 485 malloc_size = (bufsize/iflentry_size) * sizeof(void *); 486 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 487 syslog(LOG_ERR, "<%s> malloc failed", __func__); 488 exit(1); 489 } 490 491 lim = buf + bufsize; 492 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 493 if (ifm->ifm_msglen == 0) { 494 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 495 "(buf=%p lim=%p ifm=%p)", __func__, 496 buf, lim, ifm); 497 return; 498 } 499 500 if (ifm->ifm_type == RTM_IFINFO) { 501 (*ifmlist_p)[ifm->ifm_index] = ifm; 502 } else { 503 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 504 "expected %d, got %d\n msglen = %d\n" 505 "buf:%p, ifm:%p, lim:%p\n", 506 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 507 buf, ifm, lim); 508 exit (1); 509 } 510 for (ifam = (struct ifa_msghdr *) 511 ((char *)ifm + ifm->ifm_msglen); 512 ifam < (struct ifa_msghdr *)lim; 513 ifam = (struct ifa_msghdr *) 514 ((char *)ifam + ifam->ifam_msglen)) { 515 /* just for safety */ 516 if (!ifam->ifam_msglen) { 517 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 518 "(buf=%p lim=%p ifam=%p)", __func__, 519 buf, lim, ifam); 520 return; 521 } 522 if (ifam->ifam_type != RTM_NEWADDR) 523 break; 524 } 525 ifm = (struct if_msghdr *)ifam; 526 } 527 } 528 529 void 530 init_iflist() 531 { 532 if (ifblock) { 533 free(ifblock); 534 ifblock_size = 0; 535 } 536 if (iflist) 537 free(iflist); 538 /* get iflist block from kernel */ 539 get_iflist(&ifblock, &ifblock_size); 540 541 /* make list of pointers to each if_msghdr */ 542 parse_iflist(&iflist, ifblock, ifblock_size); 543 } 544