1 /* $NetBSD: if.c,v 1.14 2002/07/10 21:11:44 itojun Exp $ */ 2 /* $KAME: if.c,v 1.21 2002/05/21 14:26:55 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 int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0}; 89 char *buf, *next, *lim; 90 size_t len; 91 struct if_msghdr *ifm; 92 struct sockaddr *sa, *rti_info[RTAX_MAX]; 93 struct sockaddr_dl *sdl = NULL, *ret_sdl; 94 95 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 96 return(NULL); 97 if ((buf = malloc(len)) == NULL) 98 return(NULL); 99 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 100 free(buf); 101 return(NULL); 102 } 103 104 lim = buf + len; 105 for (next = buf; next < lim; next += ifm->ifm_msglen) { 106 ifm = (struct if_msghdr *)next; 107 if (ifm->ifm_type == RTM_IFINFO) { 108 sa = (struct sockaddr *)(ifm + 1); 109 get_rtaddrs(ifm->ifm_addrs, sa, rti_info); 110 if ((sa = rti_info[RTAX_IFP]) != NULL) { 111 if (sa->sa_family == AF_LINK) { 112 sdl = (struct sockaddr_dl *)sa; 113 if (strlen(name) != sdl->sdl_nlen) 114 continue; /* not same len */ 115 if (strncmp(&sdl->sdl_data[0], 116 name, 117 sdl->sdl_nlen) == 0) { 118 break; 119 } 120 } 121 } 122 } 123 } 124 if (next == lim) { 125 /* search failed */ 126 free(buf); 127 return(NULL); 128 } 129 130 if ((ret_sdl = malloc(sdl->sdl_len)) == NULL) 131 return(NULL); 132 memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len); 133 return(ret_sdl); 134 } 135 136 int 137 if_getmtu(char *name) 138 { 139 struct ifaddrs *ifap, *ifa; 140 struct if_data *ifd; 141 u_long mtu = 0; 142 143 if (getifaddrs(&ifap) < 0) 144 return(0); 145 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 146 if (strcmp(ifa->ifa_name, name) == 0) { 147 ifd = ifa->ifa_data; 148 if (ifd) 149 mtu = ifd->ifi_mtu; 150 break; 151 } 152 } 153 freeifaddrs(ifap); 154 155 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 156 if (mtu == 0) { 157 struct ifreq ifr; 158 int s; 159 160 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 161 return(0); 162 163 ifr.ifr_addr.sa_family = AF_INET6; 164 strncpy(ifr.ifr_name, name, 165 sizeof(ifr.ifr_name)); 166 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 167 close(s); 168 return(0); 169 } 170 close(s); 171 172 mtu = ifr.ifr_mtu; 173 } 174 #endif 175 176 return(mtu); 177 } 178 179 /* give interface index and its old flags, then new flags returned */ 180 int 181 if_getflags(int ifindex, int oifflags) 182 { 183 struct ifreq ifr; 184 int s; 185 186 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 187 syslog(LOG_ERR, "<%s> socket: %s", __func__, 188 strerror(errno)); 189 return (oifflags & ~IFF_UP); 190 } 191 192 if_indextoname(ifindex, ifr.ifr_name); 193 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 194 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 195 __func__, ifr.ifr_name); 196 close(s); 197 return (oifflags & ~IFF_UP); 198 } 199 close(s); 200 return (ifr.ifr_flags); 201 } 202 203 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 204 int 205 lladdropt_length(struct sockaddr_dl *sdl) 206 { 207 switch (sdl->sdl_type) { 208 case IFT_ETHER: 209 case IFT_FDDI: 210 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 211 default: 212 return(0); 213 } 214 } 215 216 void 217 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 218 { 219 char *addr; 220 221 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 222 223 switch (sdl->sdl_type) { 224 case IFT_ETHER: 225 case IFT_FDDI: 226 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 227 addr = (char *)(ndopt + 1); 228 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 229 break; 230 default: 231 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 232 __func__, sdl->sdl_type); 233 exit(1); 234 } 235 236 return; 237 } 238 239 int 240 rtbuf_len() 241 { 242 size_t len; 243 244 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 245 246 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 247 return(-1); 248 249 return(len); 250 } 251 252 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 253 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 254 #define SDL(s) ((struct sockaddr_dl *)(s)) 255 char * 256 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 257 { 258 struct rt_msghdr *rtm; 259 struct ifa_msghdr *ifam; 260 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 261 262 *lenp = 0; 263 for (rtm = (struct rt_msghdr *)buf; 264 rtm < (struct rt_msghdr *)lim; 265 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 266 /* just for safety */ 267 if (!rtm->rtm_msglen) { 268 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 269 "(buf=%p lim=%p rtm=%p)", __func__, 270 buf, lim, rtm); 271 break; 272 } 273 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 274 continue; 275 } 276 277 switch (rtm->rtm_type) { 278 case RTM_GET: 279 case RTM_ADD: 280 case RTM_DELETE: 281 /* address related checks */ 282 sa = (struct sockaddr *)(rtm + 1); 283 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 284 if ((dst = rti_info[RTAX_DST]) == NULL || 285 dst->sa_family != AF_INET6) 286 continue; 287 288 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 289 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 290 continue; 291 292 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 293 gw->sa_family != AF_LINK) 294 continue; 295 if (ifindex && SDL(gw)->sdl_index != ifindex) 296 continue; 297 298 if (rti_info[RTAX_NETMASK] == NULL) 299 continue; 300 301 /* found */ 302 *lenp = rtm->rtm_msglen; 303 return (char *)rtm; 304 /* NOTREACHED */ 305 case RTM_NEWADDR: 306 case RTM_DELADDR: 307 ifam = (struct ifa_msghdr *)rtm; 308 309 /* address related checks */ 310 sa = (struct sockaddr *)(ifam + 1); 311 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 312 if ((ifa = rti_info[RTAX_IFA]) == NULL || 313 (ifa->sa_family != AF_INET && 314 ifa->sa_family != AF_INET6)) 315 continue; 316 317 if (ifa->sa_family == AF_INET6 && 318 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 319 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 320 continue; 321 322 if (ifindex && ifam->ifam_index != ifindex) 323 continue; 324 325 /* found */ 326 *lenp = ifam->ifam_msglen; 327 return (char *)rtm; 328 /* NOTREACHED */ 329 case RTM_IFINFO: 330 /* found */ 331 *lenp = rtm->rtm_msglen; 332 return (char *)rtm; 333 /* NOTREACHED */ 334 } 335 } 336 337 return (char *)rtm; 338 } 339 #undef FILTER_MATCH 340 341 struct in6_addr * 342 get_addr(char *buf) 343 { 344 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 345 struct sockaddr *sa, *rti_info[RTAX_MAX]; 346 347 sa = (struct sockaddr *)(rtm + 1); 348 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 349 350 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 351 } 352 353 int 354 get_rtm_ifindex(char *buf) 355 { 356 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 357 struct sockaddr *sa, *rti_info[RTAX_MAX]; 358 359 sa = (struct sockaddr *)(rtm + 1); 360 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 361 362 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 363 } 364 365 int 366 get_ifm_ifindex(char *buf) 367 { 368 struct if_msghdr *ifm = (struct if_msghdr *)buf; 369 370 return ((int)ifm->ifm_index); 371 } 372 373 int 374 get_ifam_ifindex(char *buf) 375 { 376 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 377 378 return ((int)ifam->ifam_index); 379 } 380 381 int 382 get_ifm_flags(char *buf) 383 { 384 struct if_msghdr *ifm = (struct if_msghdr *)buf; 385 386 return (ifm->ifm_flags); 387 } 388 389 int 390 get_prefixlen(char *buf) 391 { 392 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 393 struct sockaddr *sa, *rti_info[RTAX_MAX]; 394 u_char *p, *lim; 395 396 sa = (struct sockaddr *)(rtm + 1); 397 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 398 sa = rti_info[RTAX_NETMASK]; 399 400 p = (u_char *)(&SIN6(sa)->sin6_addr); 401 lim = (u_char *)sa + sa->sa_len; 402 return prefixlen(p, lim); 403 } 404 405 int 406 prefixlen(u_char *p, u_char *lim) 407 { 408 int masklen; 409 410 for (masklen = 0; p < lim; p++) { 411 switch (*p) { 412 case 0xff: 413 masklen += 8; 414 break; 415 case 0xfe: 416 masklen += 7; 417 break; 418 case 0xfc: 419 masklen += 6; 420 break; 421 case 0xf8: 422 masklen += 5; 423 break; 424 case 0xf0: 425 masklen += 4; 426 break; 427 case 0xe0: 428 masklen += 3; 429 break; 430 case 0xc0: 431 masklen += 2; 432 break; 433 case 0x80: 434 masklen += 1; 435 break; 436 case 0x00: 437 break; 438 default: 439 return(-1); 440 } 441 } 442 443 return(masklen); 444 } 445 446 int 447 rtmsg_type(char *buf) 448 { 449 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 450 451 return(rtm->rtm_type); 452 } 453 454 int 455 rtmsg_len(char *buf) 456 { 457 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 458 459 return(rtm->rtm_msglen); 460 } 461 462 int 463 ifmsg_len(char *buf) 464 { 465 struct if_msghdr *ifm = (struct if_msghdr *)buf; 466 467 return(ifm->ifm_msglen); 468 } 469 470 /* 471 * alloc buffer and get if_msghdrs block from kernel, 472 * and put them into the buffer 473 */ 474 static void 475 get_iflist(char **buf, size_t *size) 476 { 477 int mib[6]; 478 479 mib[0] = CTL_NET; 480 mib[1] = PF_ROUTE; 481 mib[2] = 0; 482 mib[3] = AF_INET6; 483 mib[4] = NET_RT_IFLIST; 484 mib[5] = 0; 485 486 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 487 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 488 __func__); 489 exit(1); 490 } 491 if ((*buf = malloc(*size)) == NULL) { 492 syslog(LOG_ERR, "<%s> malloc failed", __func__); 493 exit(1); 494 } 495 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 496 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 497 __func__); 498 exit(1); 499 } 500 return; 501 } 502 503 /* 504 * alloc buffer and parse if_msghdrs block passed as arg, 505 * and init the buffer as list of pointers ot each of the if_msghdr. 506 */ 507 static void 508 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 509 { 510 int iflentry_size, malloc_size; 511 struct if_msghdr *ifm; 512 struct ifa_msghdr *ifam; 513 char *lim; 514 515 /* 516 * Estimate least size of an iflist entry, to be obtained from kernel. 517 * Should add sizeof(sockaddr) ?? 518 */ 519 iflentry_size = sizeof(struct if_msghdr); 520 /* roughly estimate max list size of pointers to each if_msghdr */ 521 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 522 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 523 syslog(LOG_ERR, "<%s> malloc failed", __func__); 524 exit(1); 525 } 526 527 lim = buf + bufsize; 528 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 529 if (ifm->ifm_msglen == 0) { 530 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 531 "(buf=%p lim=%p ifm=%p)", __func__, 532 buf, lim, ifm); 533 return; 534 } 535 536 if (ifm->ifm_type == RTM_IFINFO) { 537 (*ifmlist_p)[ifm->ifm_index] = ifm; 538 } else { 539 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 540 "expected %d, got %d\n msglen = %d\n" 541 "buf:%p, ifm:%p, lim:%p\n", 542 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 543 buf, ifm, lim); 544 exit (1); 545 } 546 for (ifam = (struct ifa_msghdr *) 547 ((char *)ifm + ifm->ifm_msglen); 548 ifam < (struct ifa_msghdr *)lim; 549 ifam = (struct ifa_msghdr *) 550 ((char *)ifam + ifam->ifam_msglen)) { 551 /* just for safety */ 552 if (!ifam->ifam_msglen) { 553 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 554 "(buf=%p lim=%p ifam=%p)", __func__, 555 buf, lim, ifam); 556 return; 557 } 558 if (ifam->ifam_type != RTM_NEWADDR) 559 break; 560 } 561 ifm = (struct if_msghdr *)ifam; 562 } 563 } 564 565 void 566 init_iflist() 567 { 568 if (ifblock) { 569 free(ifblock); 570 ifblock_size = 0; 571 } 572 if (iflist) 573 free(iflist); 574 /* get iflist block from kernel */ 575 get_iflist(&ifblock, &ifblock_size); 576 577 /* make list of pointers to each if_msghdr */ 578 parse_iflist(&iflist, ifblock, ifblock_size); 579 } 580