1 /* $NetBSD: if.c,v 1.17 2003/09/23 18:15:50 itojun Exp $ */ 2 /* $KAME: if.c,v 1.31 2003/09/23 10:58:20 itojun 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 int 217 rtbuf_len() 218 { 219 size_t len; 220 221 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 222 223 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 224 return(-1); 225 226 return(len); 227 } 228 229 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 230 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 231 #define SDL(s) ((struct sockaddr_dl *)(s)) 232 char * 233 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 234 { 235 struct rt_msghdr *rtm; 236 struct ifa_msghdr *ifam; 237 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 238 239 *lenp = 0; 240 for (rtm = (struct rt_msghdr *)buf; 241 rtm < (struct rt_msghdr *)lim; 242 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 243 /* just for safety */ 244 if (!rtm->rtm_msglen) { 245 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 246 "(buf=%p lim=%p rtm=%p)", __func__, 247 buf, lim, rtm); 248 break; 249 } 250 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 251 continue; 252 } 253 254 switch (rtm->rtm_type) { 255 case RTM_GET: 256 case RTM_ADD: 257 case RTM_DELETE: 258 /* address related checks */ 259 sa = (struct sockaddr *)(rtm + 1); 260 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 261 if ((dst = rti_info[RTAX_DST]) == NULL || 262 dst->sa_family != AF_INET6) 263 continue; 264 265 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 266 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 267 continue; 268 269 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 270 gw->sa_family != AF_LINK) 271 continue; 272 if (ifindex && SDL(gw)->sdl_index != ifindex) 273 continue; 274 275 if (rti_info[RTAX_NETMASK] == NULL) 276 continue; 277 278 /* found */ 279 *lenp = rtm->rtm_msglen; 280 return (char *)rtm; 281 /* NOTREACHED */ 282 case RTM_NEWADDR: 283 case RTM_DELADDR: 284 ifam = (struct ifa_msghdr *)rtm; 285 286 /* address related checks */ 287 sa = (struct sockaddr *)(ifam + 1); 288 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 289 if ((ifa = rti_info[RTAX_IFA]) == NULL || 290 (ifa->sa_family != AF_INET && 291 ifa->sa_family != AF_INET6)) 292 continue; 293 294 if (ifa->sa_family == AF_INET6 && 295 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 296 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 297 continue; 298 299 if (ifindex && ifam->ifam_index != ifindex) 300 continue; 301 302 /* found */ 303 *lenp = ifam->ifam_msglen; 304 return (char *)rtm; 305 /* NOTREACHED */ 306 case RTM_IFINFO: 307 /* found */ 308 *lenp = rtm->rtm_msglen; 309 return (char *)rtm; 310 /* NOTREACHED */ 311 } 312 } 313 314 return (char *)rtm; 315 } 316 #undef FILTER_MATCH 317 318 struct in6_addr * 319 get_addr(char *buf) 320 { 321 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 322 struct sockaddr *sa, *rti_info[RTAX_MAX]; 323 324 sa = (struct sockaddr *)(rtm + 1); 325 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 326 327 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 328 } 329 330 int 331 get_rtm_ifindex(char *buf) 332 { 333 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 334 struct sockaddr *sa, *rti_info[RTAX_MAX]; 335 336 sa = (struct sockaddr *)(rtm + 1); 337 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 338 339 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 340 } 341 342 int 343 get_ifm_ifindex(char *buf) 344 { 345 struct if_msghdr *ifm = (struct if_msghdr *)buf; 346 347 return ((int)ifm->ifm_index); 348 } 349 350 int 351 get_ifam_ifindex(char *buf) 352 { 353 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 354 355 return ((int)ifam->ifam_index); 356 } 357 358 int 359 get_ifm_flags(char *buf) 360 { 361 struct if_msghdr *ifm = (struct if_msghdr *)buf; 362 363 return (ifm->ifm_flags); 364 } 365 366 int 367 get_prefixlen(char *buf) 368 { 369 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 370 struct sockaddr *sa, *rti_info[RTAX_MAX]; 371 u_char *p, *lim; 372 373 sa = (struct sockaddr *)(rtm + 1); 374 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 375 sa = rti_info[RTAX_NETMASK]; 376 377 p = (u_char *)(&SIN6(sa)->sin6_addr); 378 lim = (u_char *)sa + sa->sa_len; 379 return prefixlen(p, lim); 380 } 381 382 int 383 prefixlen(u_char *p, u_char *lim) 384 { 385 int masklen; 386 387 for (masklen = 0; p < lim; p++) { 388 switch (*p) { 389 case 0xff: 390 masklen += 8; 391 break; 392 case 0xfe: 393 masklen += 7; 394 break; 395 case 0xfc: 396 masklen += 6; 397 break; 398 case 0xf8: 399 masklen += 5; 400 break; 401 case 0xf0: 402 masklen += 4; 403 break; 404 case 0xe0: 405 masklen += 3; 406 break; 407 case 0xc0: 408 masklen += 2; 409 break; 410 case 0x80: 411 masklen += 1; 412 break; 413 case 0x00: 414 break; 415 default: 416 return(-1); 417 } 418 } 419 420 return(masklen); 421 } 422 423 int 424 rtmsg_type(char *buf) 425 { 426 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 427 428 return(rtm->rtm_type); 429 } 430 431 int 432 rtmsg_len(char *buf) 433 { 434 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 435 436 return(rtm->rtm_msglen); 437 } 438 439 int 440 ifmsg_len(char *buf) 441 { 442 struct if_msghdr *ifm = (struct if_msghdr *)buf; 443 444 return(ifm->ifm_msglen); 445 } 446 447 /* 448 * alloc buffer and get if_msghdrs block from kernel, 449 * and put them into the buffer 450 */ 451 static void 452 get_iflist(char **buf, size_t *size) 453 { 454 int mib[6]; 455 456 mib[0] = CTL_NET; 457 mib[1] = PF_ROUTE; 458 mib[2] = 0; 459 mib[3] = AF_INET6; 460 mib[4] = NET_RT_IFLIST; 461 mib[5] = 0; 462 463 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 464 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 465 __func__); 466 exit(1); 467 } 468 if ((*buf = malloc(*size)) == NULL) { 469 syslog(LOG_ERR, "<%s> malloc failed", __func__); 470 exit(1); 471 } 472 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 473 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 474 __func__); 475 exit(1); 476 } 477 return; 478 } 479 480 /* 481 * alloc buffer and parse if_msghdrs block passed as arg, 482 * and init the buffer as list of pointers ot each of the if_msghdr. 483 */ 484 static void 485 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 486 { 487 int iflentry_size, malloc_size; 488 struct if_msghdr *ifm; 489 struct ifa_msghdr *ifam; 490 char *lim; 491 492 /* 493 * Estimate least size of an iflist entry, to be obtained from kernel. 494 * Should add sizeof(sockaddr) ?? 495 */ 496 iflentry_size = sizeof(struct if_msghdr); 497 /* roughly estimate max list size of pointers to each if_msghdr */ 498 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 499 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 500 syslog(LOG_ERR, "<%s> malloc failed", __func__); 501 exit(1); 502 } 503 504 lim = buf + bufsize; 505 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 506 if (ifm->ifm_msglen == 0) { 507 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 508 "(buf=%p lim=%p ifm=%p)", __func__, 509 buf, lim, ifm); 510 return; 511 } 512 513 if (ifm->ifm_type == RTM_IFINFO) { 514 (*ifmlist_p)[ifm->ifm_index] = ifm; 515 } else { 516 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 517 "expected %d, got %d\n msglen = %d\n" 518 "buf:%p, ifm:%p, lim:%p\n", 519 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 520 buf, ifm, lim); 521 exit (1); 522 } 523 for (ifam = (struct ifa_msghdr *) 524 ((char *)ifm + ifm->ifm_msglen); 525 ifam < (struct ifa_msghdr *)lim; 526 ifam = (struct ifa_msghdr *) 527 ((char *)ifam + ifam->ifam_msglen)) { 528 /* just for safety */ 529 if (!ifam->ifam_msglen) { 530 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 531 "(buf=%p lim=%p ifam=%p)", __func__, 532 buf, lim, ifam); 533 return; 534 } 535 if (ifam->ifam_type != RTM_NEWADDR) 536 break; 537 } 538 ifm = (struct if_msghdr *)ifam; 539 } 540 } 541 542 void 543 init_iflist() 544 { 545 if (ifblock) { 546 free(ifblock); 547 ifblock_size = 0; 548 } 549 if (iflist) 550 free(iflist); 551 /* get iflist block from kernel */ 552 get_iflist(&ifblock, &ifblock_size); 553 554 /* make list of pointers to each if_msghdr */ 555 parse_iflist(&iflist, ifblock, ifblock_size); 556 } 557