1 /* $FreeBSD$ */ 2 /* $KAME: if.c,v 1.17 2001/01/21 15:27:30 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 <net/ethernet.h> 40 #include <ifaddrs.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 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 210 default: 211 return(0); 212 } 213 } 214 215 void 216 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 217 { 218 char *addr; 219 220 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 221 222 switch (sdl->sdl_type) { 223 case IFT_ETHER: 224 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 225 addr = (char *)(ndopt + 1); 226 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 227 break; 228 default: 229 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 230 __func__, sdl->sdl_type); 231 exit(1); 232 } 233 234 return; 235 } 236 237 int 238 rtbuf_len() 239 { 240 size_t len; 241 242 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 243 244 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 245 return(-1); 246 247 return(len); 248 } 249 250 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 251 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 252 #define SDL(s) ((struct sockaddr_dl *)(s)) 253 char * 254 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 255 { 256 struct rt_msghdr *rtm; 257 struct ifa_msghdr *ifam; 258 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 259 260 *lenp = 0; 261 for (rtm = (struct rt_msghdr *)buf; 262 rtm < (struct rt_msghdr *)lim; 263 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 264 /* just for safety */ 265 if (!rtm->rtm_msglen) { 266 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 267 "(buf=%p lim=%p rtm=%p)", __func__, 268 buf, lim, rtm); 269 break; 270 } 271 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 272 continue; 273 } 274 275 switch (rtm->rtm_type) { 276 case RTM_GET: 277 case RTM_ADD: 278 case RTM_DELETE: 279 /* address related checks */ 280 sa = (struct sockaddr *)(rtm + 1); 281 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 282 if ((dst = rti_info[RTAX_DST]) == NULL || 283 dst->sa_family != AF_INET6) 284 continue; 285 286 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 287 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 288 continue; 289 290 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 291 gw->sa_family != AF_LINK) 292 continue; 293 if (ifindex && SDL(gw)->sdl_index != ifindex) 294 continue; 295 296 if (rti_info[RTAX_NETMASK] == NULL) 297 continue; 298 299 /* found */ 300 *lenp = rtm->rtm_msglen; 301 return (char *)rtm; 302 /* NOTREACHED */ 303 case RTM_NEWADDR: 304 case RTM_DELADDR: 305 ifam = (struct ifa_msghdr *)rtm; 306 307 /* address related checks */ 308 sa = (struct sockaddr *)(ifam + 1); 309 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 310 if ((ifa = rti_info[RTAX_IFA]) == NULL || 311 (ifa->sa_family != AF_INET && 312 ifa->sa_family != AF_INET6)) 313 continue; 314 315 if (ifa->sa_family == AF_INET6 && 316 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 317 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 318 continue; 319 320 if (ifindex && ifam->ifam_index != ifindex) 321 continue; 322 323 /* found */ 324 *lenp = ifam->ifam_msglen; 325 return (char *)rtm; 326 /* NOTREACHED */ 327 case RTM_IFINFO: 328 /* found */ 329 *lenp = rtm->rtm_msglen; 330 return (char *)rtm; 331 /* NOTREACHED */ 332 } 333 } 334 335 return (char *)rtm; 336 } 337 #undef FILTER_MATCH 338 339 struct in6_addr * 340 get_addr(char *buf) 341 { 342 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 343 struct sockaddr *sa, *rti_info[RTAX_MAX]; 344 345 sa = (struct sockaddr *)(rtm + 1); 346 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 347 348 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 349 } 350 351 int 352 get_rtm_ifindex(char *buf) 353 { 354 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 355 struct sockaddr *sa, *rti_info[RTAX_MAX]; 356 357 sa = (struct sockaddr *)(rtm + 1); 358 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 359 360 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 361 } 362 363 int 364 get_ifm_ifindex(char *buf) 365 { 366 struct if_msghdr *ifm = (struct if_msghdr *)buf; 367 368 return ((int)ifm->ifm_index); 369 } 370 371 int 372 get_ifam_ifindex(char *buf) 373 { 374 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 375 376 return ((int)ifam->ifam_index); 377 } 378 379 int 380 get_ifm_flags(char *buf) 381 { 382 struct if_msghdr *ifm = (struct if_msghdr *)buf; 383 384 return (ifm->ifm_flags); 385 } 386 387 int 388 get_prefixlen(char *buf) 389 { 390 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 391 struct sockaddr *sa, *rti_info[RTAX_MAX]; 392 u_char *p, *lim; 393 394 sa = (struct sockaddr *)(rtm + 1); 395 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 396 sa = rti_info[RTAX_NETMASK]; 397 398 p = (u_char *)(&SIN6(sa)->sin6_addr); 399 lim = (u_char *)sa + sa->sa_len; 400 return prefixlen(p, lim); 401 } 402 403 int 404 prefixlen(u_char *p, u_char *lim) 405 { 406 int masklen; 407 408 for (masklen = 0; p < lim; p++) { 409 switch (*p) { 410 case 0xff: 411 masklen += 8; 412 break; 413 case 0xfe: 414 masklen += 7; 415 break; 416 case 0xfc: 417 masklen += 6; 418 break; 419 case 0xf8: 420 masklen += 5; 421 break; 422 case 0xf0: 423 masklen += 4; 424 break; 425 case 0xe0: 426 masklen += 3; 427 break; 428 case 0xc0: 429 masklen += 2; 430 break; 431 case 0x80: 432 masklen += 1; 433 break; 434 case 0x00: 435 break; 436 default: 437 return(-1); 438 } 439 } 440 441 return(masklen); 442 } 443 444 int 445 rtmsg_type(char *buf) 446 { 447 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 448 449 return(rtm->rtm_type); 450 } 451 452 int 453 rtmsg_len(char *buf) 454 { 455 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 456 457 return(rtm->rtm_msglen); 458 } 459 460 int 461 ifmsg_len(char *buf) 462 { 463 struct if_msghdr *ifm = (struct if_msghdr *)buf; 464 465 return(ifm->ifm_msglen); 466 } 467 468 /* 469 * alloc buffer and get if_msghdrs block from kernel, 470 * and put them into the buffer 471 */ 472 static void 473 get_iflist(char **buf, size_t *size) 474 { 475 int mib[6]; 476 477 mib[0] = CTL_NET; 478 mib[1] = PF_ROUTE; 479 mib[2] = 0; 480 mib[3] = AF_INET6; 481 mib[4] = NET_RT_IFLIST; 482 mib[5] = 0; 483 484 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 485 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 486 __func__); 487 exit(1); 488 } 489 if ((*buf = malloc(*size)) == NULL) { 490 syslog(LOG_ERR, "<%s> malloc failed", __func__); 491 exit(1); 492 } 493 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 494 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 495 __func__); 496 exit(1); 497 } 498 return; 499 } 500 501 /* 502 * alloc buffer and parse if_msghdrs block passed as arg, 503 * and init the buffer as list of pointers ot each of the if_msghdr. 504 */ 505 static void 506 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 507 { 508 int iflentry_size, malloc_size; 509 struct if_msghdr *ifm; 510 struct ifa_msghdr *ifam; 511 char *lim; 512 513 /* 514 * Estimate least size of an iflist entry, to be obtained from kernel. 515 * Should add sizeof(sockaddr) ?? 516 */ 517 iflentry_size = sizeof(struct if_msghdr); 518 /* roughly estimate max list size of pointers to each if_msghdr */ 519 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 520 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 521 syslog(LOG_ERR, "<%s> malloc failed", __func__); 522 exit(1); 523 } 524 525 lim = buf + bufsize; 526 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 527 if (ifm->ifm_msglen == 0) { 528 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 529 "(buf=%p lim=%p ifm=%p)", __func__, 530 buf, lim, ifm); 531 return; 532 } 533 534 if (ifm->ifm_type == RTM_IFINFO) { 535 (*ifmlist_p)[ifm->ifm_index] = ifm; 536 } else { 537 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 538 "expected %d, got %d\n msglen = %d\n" 539 "buf:%p, ifm:%p, lim:%p\n", 540 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 541 buf, ifm, lim); 542 exit (1); 543 } 544 for (ifam = (struct ifa_msghdr *) 545 ((char *)ifm + ifm->ifm_msglen); 546 ifam < (struct ifa_msghdr *)lim; 547 ifam = (struct ifa_msghdr *) 548 ((char *)ifam + ifam->ifam_msglen)) { 549 /* just for safety */ 550 if (!ifam->ifam_msglen) { 551 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 552 "(buf=%p lim=%p ifam=%p)", __func__, 553 buf, lim, ifam); 554 return; 555 } 556 if (ifam->ifam_type != RTM_NEWADDR) 557 break; 558 } 559 ifm = (struct if_msghdr *)ifam; 560 } 561 } 562 563 void 564 init_iflist() 565 { 566 if (ifblock) { 567 free(ifblock); 568 ifblock_size = 0; 569 } 570 if (iflist) 571 free(iflist); 572 /* get iflist block from kernel */ 573 get_iflist(&ifblock, &ifblock_size); 574 575 /* make list of pointers to each if_msghdr */ 576 parse_iflist(&iflist, ifblock, ifblock_size); 577 } 578