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(char **buf, size_t *size); 67 static void parse_iflist(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 goto end; 132 memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len); 133 134 end: 135 free(buf); 136 return(ret_sdl); 137 } 138 139 int 140 if_getmtu(char *name) 141 { 142 struct ifaddrs *ifap, *ifa; 143 struct if_data *ifd; 144 u_long mtu = 0; 145 146 if (getifaddrs(&ifap) < 0) 147 return(0); 148 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 149 if (strcmp(ifa->ifa_name, name) == 0) { 150 ifd = ifa->ifa_data; 151 if (ifd) 152 mtu = ifd->ifi_mtu; 153 break; 154 } 155 } 156 freeifaddrs(ifap); 157 158 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 159 if (mtu == 0) { 160 struct ifreq ifr; 161 int s; 162 163 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 164 return(0); 165 166 ifr.ifr_addr.sa_family = AF_INET6; 167 strncpy(ifr.ifr_name, name, 168 sizeof(ifr.ifr_name)); 169 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 170 close(s); 171 return(0); 172 } 173 close(s); 174 175 mtu = ifr.ifr_mtu; 176 } 177 #endif 178 179 return(mtu); 180 } 181 182 /* give interface index and its old flags, then new flags returned */ 183 int 184 if_getflags(int ifindex, int oifflags) 185 { 186 struct ifreq ifr; 187 int s; 188 189 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 190 syslog(LOG_ERR, "<%s> socket: %s", __func__, 191 strerror(errno)); 192 return (oifflags & ~IFF_UP); 193 } 194 195 if_indextoname(ifindex, ifr.ifr_name); 196 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 197 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 198 __func__, ifr.ifr_name); 199 close(s); 200 return (oifflags & ~IFF_UP); 201 } 202 close(s); 203 return (ifr.ifr_flags); 204 } 205 206 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 207 int 208 lladdropt_length(struct sockaddr_dl *sdl) 209 { 210 switch (sdl->sdl_type) { 211 case IFT_ETHER: 212 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 213 default: 214 return(0); 215 } 216 } 217 218 void 219 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 220 { 221 char *addr; 222 223 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 224 225 switch (sdl->sdl_type) { 226 case IFT_ETHER: 227 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 228 addr = (char *)(ndopt + 1); 229 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 230 break; 231 default: 232 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 233 __func__, sdl->sdl_type); 234 exit(1); 235 } 236 237 return; 238 } 239 240 int 241 rtbuf_len() 242 { 243 size_t len; 244 245 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 246 247 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 248 return(-1); 249 250 return(len); 251 } 252 253 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 254 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 255 #define SDL(s) ((struct sockaddr_dl *)(s)) 256 char * 257 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 258 { 259 struct rt_msghdr *rtm; 260 struct ifa_msghdr *ifam; 261 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 262 263 *lenp = 0; 264 for (rtm = (struct rt_msghdr *)buf; 265 rtm < (struct rt_msghdr *)lim; 266 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 267 /* just for safety */ 268 if (!rtm->rtm_msglen) { 269 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 270 "(buf=%p lim=%p rtm=%p)", __func__, 271 buf, lim, rtm); 272 break; 273 } 274 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 275 continue; 276 } 277 278 switch (rtm->rtm_type) { 279 case RTM_GET: 280 case RTM_ADD: 281 case RTM_DELETE: 282 /* address related checks */ 283 sa = (struct sockaddr *)(rtm + 1); 284 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 285 if ((dst = rti_info[RTAX_DST]) == NULL || 286 dst->sa_family != AF_INET6) 287 continue; 288 289 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 290 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 291 continue; 292 293 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 294 gw->sa_family != AF_LINK) 295 continue; 296 if (ifindex && SDL(gw)->sdl_index != ifindex) 297 continue; 298 299 if (rti_info[RTAX_NETMASK] == NULL) 300 continue; 301 302 /* found */ 303 *lenp = rtm->rtm_msglen; 304 return (char *)rtm; 305 /* NOTREACHED */ 306 case RTM_NEWADDR: 307 case RTM_DELADDR: 308 ifam = (struct ifa_msghdr *)rtm; 309 310 /* address related checks */ 311 sa = (struct sockaddr *)(ifam + 1); 312 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 313 if ((ifa = rti_info[RTAX_IFA]) == NULL || 314 (ifa->sa_family != AF_INET && 315 ifa->sa_family != AF_INET6)) 316 continue; 317 318 if (ifa->sa_family == AF_INET6 && 319 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 320 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 321 continue; 322 323 if (ifindex && ifam->ifam_index != ifindex) 324 continue; 325 326 /* found */ 327 *lenp = ifam->ifam_msglen; 328 return (char *)rtm; 329 /* NOTREACHED */ 330 case RTM_IFINFO: 331 /* found */ 332 *lenp = rtm->rtm_msglen; 333 return (char *)rtm; 334 /* NOTREACHED */ 335 } 336 } 337 338 return (char *)rtm; 339 } 340 #undef FILTER_MATCH 341 342 struct in6_addr * 343 get_addr(char *buf) 344 { 345 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 346 struct sockaddr *sa, *rti_info[RTAX_MAX]; 347 348 sa = (struct sockaddr *)(rtm + 1); 349 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 350 351 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 352 } 353 354 int 355 get_rtm_ifindex(char *buf) 356 { 357 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 358 struct sockaddr *sa, *rti_info[RTAX_MAX]; 359 360 sa = (struct sockaddr *)(rtm + 1); 361 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 362 363 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 364 } 365 366 int 367 get_ifm_ifindex(char *buf) 368 { 369 struct if_msghdr *ifm = (struct if_msghdr *)buf; 370 371 return ((int)ifm->ifm_index); 372 } 373 374 int 375 get_ifam_ifindex(char *buf) 376 { 377 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 378 379 return ((int)ifam->ifam_index); 380 } 381 382 int 383 get_ifm_flags(char *buf) 384 { 385 struct if_msghdr *ifm = (struct if_msghdr *)buf; 386 387 return (ifm->ifm_flags); 388 } 389 390 int 391 get_prefixlen(char *buf) 392 { 393 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 394 struct sockaddr *sa, *rti_info[RTAX_MAX]; 395 u_char *p, *lim; 396 397 sa = (struct sockaddr *)(rtm + 1); 398 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 399 sa = rti_info[RTAX_NETMASK]; 400 401 p = (u_char *)(&SIN6(sa)->sin6_addr); 402 lim = (u_char *)sa + sa->sa_len; 403 return prefixlen(p, lim); 404 } 405 406 int 407 prefixlen(u_char *p, u_char *lim) 408 { 409 int masklen; 410 411 for (masklen = 0; p < lim; p++) { 412 switch (*p) { 413 case 0xff: 414 masklen += 8; 415 break; 416 case 0xfe: 417 masklen += 7; 418 break; 419 case 0xfc: 420 masklen += 6; 421 break; 422 case 0xf8: 423 masklen += 5; 424 break; 425 case 0xf0: 426 masklen += 4; 427 break; 428 case 0xe0: 429 masklen += 3; 430 break; 431 case 0xc0: 432 masklen += 2; 433 break; 434 case 0x80: 435 masklen += 1; 436 break; 437 case 0x00: 438 break; 439 default: 440 return(-1); 441 } 442 } 443 444 return(masklen); 445 } 446 447 int 448 rtmsg_type(char *buf) 449 { 450 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 451 452 return(rtm->rtm_type); 453 } 454 455 int 456 rtmsg_len(char *buf) 457 { 458 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 459 460 return(rtm->rtm_msglen); 461 } 462 463 int 464 ifmsg_len(char *buf) 465 { 466 struct if_msghdr *ifm = (struct if_msghdr *)buf; 467 468 return(ifm->ifm_msglen); 469 } 470 471 /* 472 * alloc buffer and get if_msghdrs block from kernel, 473 * and put them into the buffer 474 */ 475 static void 476 get_iflist(char **buf, size_t *size) 477 { 478 int mib[6]; 479 480 mib[0] = CTL_NET; 481 mib[1] = PF_ROUTE; 482 mib[2] = 0; 483 mib[3] = AF_INET6; 484 mib[4] = NET_RT_IFLIST; 485 mib[5] = 0; 486 487 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 488 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 489 __func__); 490 exit(1); 491 } 492 if ((*buf = malloc(*size)) == NULL) { 493 syslog(LOG_ERR, "<%s> malloc failed", __func__); 494 exit(1); 495 } 496 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 497 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 498 __func__); 499 exit(1); 500 } 501 return; 502 } 503 504 /* 505 * alloc buffer and parse if_msghdrs block passed as arg, 506 * and init the buffer as list of pointers ot each of the if_msghdr. 507 */ 508 static void 509 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 510 { 511 int iflentry_size, malloc_size; 512 struct if_msghdr *ifm; 513 struct ifa_msghdr *ifam; 514 char *lim; 515 516 /* 517 * Estimate least size of an iflist entry, to be obtained from kernel. 518 * Should add sizeof(sockaddr) ?? 519 */ 520 iflentry_size = sizeof(struct if_msghdr); 521 /* roughly estimate max list size of pointers to each if_msghdr */ 522 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 523 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 524 syslog(LOG_ERR, "<%s> malloc failed", __func__); 525 exit(1); 526 } 527 528 lim = buf + bufsize; 529 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 530 if (ifm->ifm_msglen == 0) { 531 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 532 "(buf=%p lim=%p ifm=%p)", __func__, 533 buf, lim, ifm); 534 return; 535 } 536 537 if (ifm->ifm_type == RTM_IFINFO) { 538 (*ifmlist_p)[ifm->ifm_index] = ifm; 539 } else { 540 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 541 "expected %d, got %d\n msglen = %d\n" 542 "buf:%p, ifm:%p, lim:%p\n", 543 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 544 buf, ifm, lim); 545 exit (1); 546 } 547 for (ifam = (struct ifa_msghdr *) 548 ((char *)ifm + ifm->ifm_msglen); 549 ifam < (struct ifa_msghdr *)lim; 550 ifam = (struct ifa_msghdr *) 551 ((char *)ifam + ifam->ifam_msglen)) { 552 /* just for safety */ 553 if (!ifam->ifam_msglen) { 554 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 555 "(buf=%p lim=%p ifam=%p)", __func__, 556 buf, lim, ifam); 557 return; 558 } 559 if (ifam->ifam_type != RTM_NEWADDR) 560 break; 561 } 562 ifm = (struct if_msghdr *)ifam; 563 } 564 } 565 566 void 567 init_iflist() 568 { 569 if (ifblock) { 570 free(ifblock); 571 ifblock_size = 0; 572 } 573 if (iflist) 574 free(iflist); 575 /* get iflist block from kernel */ 576 get_iflist(&ifblock, &ifblock_size); 577 578 /* make list of pointers to each if_msghdr */ 579 parse_iflist(&iflist, ifblock, ifblock_size); 580 } 581