1 /* $KAME: if.c,v 1.17 2001/01/21 15:27:30 itojun Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD: src/usr.sbin/rtadvd/if.c,v 1.2.2.3 2001/07/03 11:02:14 ume Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/socket.h> 36 #include <sys/sysctl.h> 37 #include <sys/ioctl.h> 38 #include <net/if.h> 39 #include <net/if_types.h> 40 #ifdef __FreeBSD__ 41 # include <net/ethernet.h> 42 #endif 43 #include <ifaddrs.h> 44 #ifdef __NetBSD__ 45 #include <net/if_ether.h> 46 #endif 47 #include <net/route.h> 48 #include <net/if_dl.h> 49 #include <netinet/in.h> 50 #include <netinet/icmp6.h> 51 #ifdef __bsdi__ 52 # include <netinet/if_ether.h> 53 #endif 54 #ifdef __OpenBSD__ 55 #include <netinet/if_ether.h> 56 #endif 57 #include <unistd.h> 58 #include <errno.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <syslog.h> 62 #include "rtadvd.h" 63 #include "if.h" 64 65 #define ROUNDUP(a, size) \ 66 (((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a)) 67 68 #define NEXT_SA(ap) (ap) = (struct sockaddr *) \ 69 ((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\ 70 sizeof(u_long)) :\ 71 sizeof(u_long))) 72 73 struct if_msghdr **iflist; 74 int iflist_init_ok; 75 size_t ifblock_size; 76 char *ifblock; 77 78 static void get_iflist __P((char **buf, size_t *size)); 79 static void parse_iflist __P((struct if_msghdr ***ifmlist_p, char *buf, 80 size_t bufsize)); 81 82 static void 83 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 84 { 85 int i; 86 87 for (i = 0; i < RTAX_MAX; i++) { 88 if (addrs & (1 << i)) { 89 rti_info[i] = sa; 90 NEXT_SA(sa); 91 } 92 else 93 rti_info[i] = NULL; 94 } 95 } 96 97 struct sockaddr_dl * 98 if_nametosdl(char *name) 99 { 100 int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0}; 101 char *buf, *next, *lim; 102 size_t len; 103 struct if_msghdr *ifm; 104 struct sockaddr *sa, *rti_info[RTAX_MAX]; 105 struct sockaddr_dl *sdl = NULL, *ret_sdl; 106 107 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 108 return(NULL); 109 if ((buf = malloc(len)) == NULL) 110 return(NULL); 111 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 112 free(buf); 113 return(NULL); 114 } 115 116 lim = buf + len; 117 for (next = buf; next < lim; next += ifm->ifm_msglen) { 118 ifm = (struct if_msghdr *)next; 119 if (ifm->ifm_type == RTM_IFINFO) { 120 sa = (struct sockaddr *)(ifm + 1); 121 get_rtaddrs(ifm->ifm_addrs, sa, rti_info); 122 if ((sa = rti_info[RTAX_IFP]) != NULL) { 123 if (sa->sa_family == AF_LINK) { 124 sdl = (struct sockaddr_dl *)sa; 125 if (strlen(name) != sdl->sdl_nlen) 126 continue; /* not same len */ 127 if (strncmp(&sdl->sdl_data[0], 128 name, 129 sdl->sdl_nlen) == 0) { 130 break; 131 } 132 } 133 } 134 } 135 } 136 if (next == lim) { 137 /* search failed */ 138 free(buf); 139 return(NULL); 140 } 141 142 if ((ret_sdl = malloc(sdl->sdl_len)) == NULL) 143 return(NULL); 144 memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len); 145 return(ret_sdl); 146 } 147 148 int 149 if_getmtu(char *name) 150 { 151 struct ifaddrs *ifap, *ifa; 152 struct if_data *ifd; 153 u_long mtu = 0; 154 155 if (getifaddrs(&ifap) < 0) 156 return(0); 157 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 158 if (strcmp(ifa->ifa_name, name) == 0) { 159 ifd = ifa->ifa_data; 160 if (ifd) 161 mtu = ifd->ifi_mtu; 162 break; 163 } 164 } 165 freeifaddrs(ifap); 166 167 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 168 if (mtu == 0) { 169 struct ifreq ifr; 170 int s; 171 172 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 173 return(0); 174 175 ifr.ifr_addr.sa_family = AF_INET6; 176 strncpy(ifr.ifr_name, name, 177 sizeof(ifr.ifr_name)); 178 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 179 close(s); 180 return(0); 181 } 182 close(s); 183 184 mtu = ifr.ifr_mtu; 185 } 186 #endif 187 188 return(mtu); 189 } 190 191 /* give interface index and its old flags, then new flags returned */ 192 int 193 if_getflags(int ifindex, int oifflags) 194 { 195 struct ifreq ifr; 196 int s; 197 198 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 199 syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__, 200 strerror(errno)); 201 return (oifflags & ~IFF_UP); 202 } 203 204 if_indextoname(ifindex, ifr.ifr_name); 205 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 206 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 207 __FUNCTION__, ifr.ifr_name); 208 close(s); 209 return (oifflags & ~IFF_UP); 210 } 211 close(s); 212 return (ifr.ifr_flags); 213 } 214 215 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 216 int 217 lladdropt_length(struct sockaddr_dl *sdl) 218 { 219 switch(sdl->sdl_type) { 220 case IFT_ETHER: 221 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 222 default: 223 return(0); 224 } 225 } 226 227 void 228 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 229 { 230 char *addr; 231 232 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 233 234 switch(sdl->sdl_type) { 235 case IFT_ETHER: 236 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 237 addr = (char *)(ndopt + 1); 238 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 239 break; 240 default: 241 syslog(LOG_ERR, 242 "<%s> unsupported link type(%d)", 243 __FUNCTION__, sdl->sdl_type); 244 exit(1); 245 } 246 247 return; 248 } 249 250 int 251 rtbuf_len() 252 { 253 size_t len; 254 255 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 256 257 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 258 return(-1); 259 260 return(len); 261 } 262 263 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 264 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 265 #define SDL(s) ((struct sockaddr_dl *)(s)) 266 char * 267 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 268 { 269 struct rt_msghdr *rtm; 270 struct ifa_msghdr *ifam; 271 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 272 273 *lenp = 0; 274 for (rtm = (struct rt_msghdr *)buf; 275 rtm < (struct rt_msghdr *)lim; 276 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 277 /* just for safety */ 278 if (!rtm->rtm_msglen) { 279 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 280 "(buf=%p lim=%p rtm=%p)", __FUNCTION__, 281 buf, lim, rtm); 282 break; 283 } 284 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 285 continue; 286 } 287 288 switch (rtm->rtm_type) { 289 case RTM_GET: 290 case RTM_ADD: 291 case RTM_DELETE: 292 /* address related checks */ 293 sa = (struct sockaddr *)(rtm + 1); 294 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 295 if ((dst = rti_info[RTAX_DST]) == NULL || 296 dst->sa_family != AF_INET6) 297 continue; 298 299 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 300 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 301 continue; 302 303 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 304 gw->sa_family != AF_LINK) 305 continue; 306 if (ifindex && SDL(gw)->sdl_index != ifindex) 307 continue; 308 309 if (rti_info[RTAX_NETMASK] == NULL) 310 continue; 311 312 /* found */ 313 *lenp = rtm->rtm_msglen; 314 return (char *)rtm; 315 /* NOTREACHED */ 316 case RTM_NEWADDR: 317 case RTM_DELADDR: 318 ifam = (struct ifa_msghdr *)rtm; 319 320 /* address related checks */ 321 sa = (struct sockaddr *)(ifam + 1); 322 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 323 if ((ifa = rti_info[RTAX_IFA]) == NULL || 324 (ifa->sa_family != AF_INET && 325 ifa->sa_family != AF_INET6)) 326 continue; 327 328 if (ifa->sa_family == AF_INET6 && 329 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 330 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 331 continue; 332 333 if (ifindex && ifam->ifam_index != ifindex) 334 continue; 335 336 /* found */ 337 *lenp = ifam->ifam_msglen; 338 return (char *)rtm; 339 /* NOTREACHED */ 340 case RTM_IFINFO: 341 /* found */ 342 *lenp = rtm->rtm_msglen; 343 return (char *)rtm; 344 /* NOTREACHED */ 345 } 346 } 347 348 return (char *)rtm; 349 } 350 #undef FILTER_MATCH 351 352 struct in6_addr * 353 get_addr(char *buf) 354 { 355 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 356 struct sockaddr *sa, *rti_info[RTAX_MAX]; 357 358 sa = (struct sockaddr *)(rtm + 1); 359 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 360 361 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 362 } 363 364 int 365 get_rtm_ifindex(char *buf) 366 { 367 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 368 struct sockaddr *sa, *rti_info[RTAX_MAX]; 369 370 sa = (struct sockaddr *)(rtm + 1); 371 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 372 373 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 374 } 375 376 int 377 get_ifm_ifindex(char *buf) 378 { 379 struct if_msghdr *ifm = (struct if_msghdr *)buf; 380 381 return ((int)ifm->ifm_index); 382 } 383 384 int 385 get_ifam_ifindex(char *buf) 386 { 387 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 388 389 return ((int)ifam->ifam_index); 390 } 391 392 int 393 get_ifm_flags(char *buf) 394 { 395 struct if_msghdr *ifm = (struct if_msghdr *)buf; 396 397 return (ifm->ifm_flags); 398 } 399 400 int 401 get_prefixlen(char *buf) 402 { 403 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 404 struct sockaddr *sa, *rti_info[RTAX_MAX]; 405 u_char *p, *lim; 406 407 sa = (struct sockaddr *)(rtm + 1); 408 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 409 sa = rti_info[RTAX_NETMASK]; 410 411 p = (u_char *)(&SIN6(sa)->sin6_addr); 412 lim = (u_char *)sa + sa->sa_len; 413 return prefixlen(p, lim); 414 } 415 416 int 417 prefixlen(u_char *p, u_char *lim) 418 { 419 int masklen; 420 421 for (masklen = 0; p < lim; p++) { 422 switch (*p) { 423 case 0xff: 424 masklen += 8; 425 break; 426 case 0xfe: 427 masklen += 7; 428 break; 429 case 0xfc: 430 masklen += 6; 431 break; 432 case 0xf8: 433 masklen += 5; 434 break; 435 case 0xf0: 436 masklen += 4; 437 break; 438 case 0xe0: 439 masklen += 3; 440 break; 441 case 0xc0: 442 masklen += 2; 443 break; 444 case 0x80: 445 masklen += 1; 446 break; 447 case 0x00: 448 break; 449 default: 450 return(-1); 451 } 452 } 453 454 return(masklen); 455 } 456 457 int 458 rtmsg_type(char *buf) 459 { 460 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 461 462 return(rtm->rtm_type); 463 } 464 465 int 466 rtmsg_len(char *buf) 467 { 468 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 469 470 return(rtm->rtm_msglen); 471 } 472 473 int 474 ifmsg_len(char *buf) 475 { 476 struct if_msghdr *ifm = (struct if_msghdr *)buf; 477 478 return(ifm->ifm_msglen); 479 } 480 481 /* 482 * alloc buffer and get if_msghdrs block from kernel, 483 * and put them into the buffer 484 */ 485 static void 486 get_iflist(char **buf, size_t *size) 487 { 488 int mib[6]; 489 490 mib[0] = CTL_NET; 491 mib[1] = PF_ROUTE; 492 mib[2] = 0; 493 mib[3] = AF_INET6; 494 mib[4] = NET_RT_IFLIST; 495 mib[5] = 0; 496 497 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 498 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 499 __FUNCTION__); 500 exit(1); 501 } 502 if ((*buf = malloc(*size)) == NULL) { 503 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__); 504 exit(1); 505 } 506 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 507 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 508 __FUNCTION__); 509 exit(1); 510 } 511 return; 512 } 513 514 /* 515 * alloc buffer and parse if_msghdrs block passed as arg, 516 * and init the buffer as list of pointers ot each of the if_msghdr. 517 */ 518 static void 519 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 520 { 521 int iflentry_size, malloc_size; 522 struct if_msghdr *ifm; 523 struct ifa_msghdr *ifam; 524 char *lim; 525 526 /* 527 * Estimate least size of an iflist entry, to be obtained from kernel. 528 * Should add sizeof(sockaddr) ?? 529 */ 530 iflentry_size = sizeof(struct if_msghdr); 531 /* roughly estimate max list size of pointers to each if_msghdr */ 532 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 533 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 534 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__); 535 exit(1); 536 } 537 538 lim = buf + bufsize; 539 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 540 if (ifm->ifm_msglen == 0) { 541 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 542 "(buf=%p lim=%p ifm=%p)", __FUNCTION__, 543 buf, lim, ifm); 544 return; 545 } 546 547 if (ifm->ifm_type == RTM_IFINFO) { 548 (*ifmlist_p)[ifm->ifm_index] = ifm; 549 } else { 550 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 551 "expected %d, got %d\n msglen = %d\n" 552 "buf:%p, ifm:%p, lim:%p\n", 553 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 554 buf, ifm, lim); 555 exit (1); 556 } 557 for (ifam = (struct ifa_msghdr *) 558 ((char *)ifm + ifm->ifm_msglen); 559 ifam < (struct ifa_msghdr *)lim; 560 ifam = (struct ifa_msghdr *) 561 ((char *)ifam + ifam->ifam_msglen)) { 562 /* just for safety */ 563 if (!ifam->ifam_msglen) { 564 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 565 "(buf=%p lim=%p ifam=%p)", __FUNCTION__, 566 buf, lim, ifam); 567 return; 568 } 569 if (ifam->ifam_type != RTM_NEWADDR) 570 break; 571 } 572 ifm = (struct if_msghdr *)ifam; 573 } 574 } 575 576 void 577 init_iflist() 578 { 579 if (ifblock) { 580 free(ifblock); 581 ifblock_size = 0; 582 } 583 if (iflist) 584 free(iflist); 585 /* get iflist block from kernel */ 586 get_iflist(&ifblock, &ifblock_size); 587 588 /* make list of pointers to each if_msghdr */ 589 parse_iflist(&iflist, ifblock, ifblock_size); 590 } 591