1 /* $FreeBSD$ */ 2 /* $KAME: if.c,v 1.14 2000/10/25 04:28:34 jinmei 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 #ifdef __FreeBSD__ 40 # include <net/ethernet.h> 41 #endif 42 #include <ifaddrs.h> 43 #ifdef __NetBSD__ 44 #include <net/if_ether.h> 45 #endif 46 #include <net/route.h> 47 #include <net/if_dl.h> 48 #include <netinet/in.h> 49 #include <netinet/icmp6.h> 50 #ifdef __bsdi__ 51 # include <netinet/if_ether.h> 52 #endif 53 #ifdef __OpenBSD__ 54 #include <netinet/if_ether.h> 55 #endif 56 #include <unistd.h> 57 #include <errno.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <syslog.h> 61 #include "rtadvd.h" 62 #include "if.h" 63 64 #define ROUNDUP(a, size) \ 65 (((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a)) 66 67 #define NEXT_SA(ap) (ap) = (struct sockaddr *) \ 68 ((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\ 69 sizeof(u_long)) :\ 70 sizeof(u_long))) 71 72 struct if_msghdr **iflist; 73 int iflist_init_ok; 74 size_t ifblock_size; 75 char *ifblock; 76 77 static void get_iflist __P((char **buf, size_t *size)); 78 static void parse_iflist __P((struct if_msghdr ***ifmlist_p, char *buf, 79 size_t bufsize)); 80 81 static void 82 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 83 { 84 int i; 85 86 for (i = 0; i < RTAX_MAX; i++) { 87 if (addrs & (1 << i)) { 88 rti_info[i] = sa; 89 NEXT_SA(sa); 90 } 91 else 92 rti_info[i] = NULL; 93 } 94 } 95 96 struct sockaddr_dl * 97 if_nametosdl(char *name) 98 { 99 int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0}; 100 char *buf, *next, *lim; 101 size_t len; 102 struct if_msghdr *ifm; 103 struct sockaddr *sa, *rti_info[RTAX_MAX]; 104 struct sockaddr_dl *sdl = NULL, *ret_sdl; 105 106 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 107 return(NULL); 108 if ((buf = malloc(len)) == NULL) 109 return(NULL); 110 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 111 free(buf); 112 return(NULL); 113 } 114 115 lim = buf + len; 116 for (next = buf; next < lim; next += ifm->ifm_msglen) { 117 ifm = (struct if_msghdr *)next; 118 if (ifm->ifm_type == RTM_IFINFO) { 119 sa = (struct sockaddr *)(ifm + 1); 120 get_rtaddrs(ifm->ifm_addrs, sa, rti_info); 121 if ((sa = rti_info[RTAX_IFP]) != NULL) { 122 if (sa->sa_family == AF_LINK) { 123 sdl = (struct sockaddr_dl *)sa; 124 if (strlen(name) != sdl->sdl_nlen) 125 continue; /* not same len */ 126 if (strncmp(&sdl->sdl_data[0], 127 name, 128 sdl->sdl_nlen) == 0) { 129 break; 130 } 131 } 132 } 133 } 134 } 135 if (next == lim) { 136 /* search failed */ 137 free(buf); 138 return(NULL); 139 } 140 141 if ((ret_sdl = malloc(sdl->sdl_len)) == NULL) 142 return(NULL); 143 memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len); 144 return(ret_sdl); 145 } 146 147 int 148 if_getmtu(char *name) 149 { 150 struct ifaddrs *ifap, *ifa; 151 struct if_data *ifd; 152 u_long mtu = 0; 153 154 if (getifaddrs(&ifap) < 0) 155 return(0); 156 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 157 if (strcmp(ifa->ifa_name, name) == 0) { 158 ifd = ifa->ifa_data; 159 if (ifd) 160 mtu = ifd->ifi_mtu; 161 break; 162 } 163 } 164 freeifaddrs(ifap); 165 166 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 167 if (mtu == 0) { 168 struct ifreq ifr; 169 int s; 170 171 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 172 return(0); 173 174 ifr.ifr_addr.sa_family = AF_INET6; 175 strncpy(ifr.ifr_name, name, 176 sizeof(ifr.ifr_name)); 177 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 178 close(s); 179 return(0); 180 } 181 close(s); 182 183 mtu = ifr.ifr_mtu; 184 } 185 #endif 186 187 return(mtu); 188 } 189 190 /* give interface index and its old flags, then new flags returned */ 191 int 192 if_getflags(int ifindex, int oifflags) 193 { 194 struct ifreq ifr; 195 int s; 196 197 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 198 syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__, 199 strerror(errno)); 200 return (oifflags & ~IFF_UP); 201 } 202 203 if_indextoname(ifindex, ifr.ifr_name); 204 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 205 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 206 __FUNCTION__, ifr.ifr_name); 207 close(s); 208 return (oifflags & ~IFF_UP); 209 } 210 close(s); 211 return (ifr.ifr_flags); 212 } 213 214 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 215 int 216 lladdropt_length(struct sockaddr_dl *sdl) 217 { 218 switch(sdl->sdl_type) { 219 case IFT_ETHER: 220 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 221 default: 222 return(0); 223 } 224 } 225 226 void 227 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 228 { 229 char *addr; 230 231 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 232 233 switch(sdl->sdl_type) { 234 case IFT_ETHER: 235 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 236 addr = (char *)(ndopt + 1); 237 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 238 break; 239 default: 240 syslog(LOG_ERR, 241 "<%s> unsupported link type(%d)", 242 __FUNCTION__, sdl->sdl_type); 243 exit(1); 244 } 245 246 return; 247 } 248 249 int 250 rtbuf_len() 251 { 252 size_t len; 253 254 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 255 256 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 257 return(-1); 258 259 return(len); 260 } 261 262 int 263 get_rtinfo(char *buf, size_t *len) 264 { 265 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 266 267 if (sysctl(mib, 6, buf, len, NULL, 0) < 0) 268 return(-1); 269 270 return(0); 271 } 272 273 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 274 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 275 #define SDL(s) ((struct sockaddr_dl *)(s)) 276 char * 277 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 278 { 279 struct rt_msghdr *rtm; 280 struct ifa_msghdr *ifam; 281 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 282 283 *lenp = 0; 284 for (rtm = (struct rt_msghdr *)buf; 285 rtm < (struct rt_msghdr *)lim; 286 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 287 /* just for safety */ 288 if (!rtm->rtm_msglen) { 289 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 290 "(buf=%p lim=%p rtm=%p)", __FUNCTION__, 291 buf, lim, rtm); 292 break; 293 } 294 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 295 continue; 296 } 297 298 switch (rtm->rtm_type) { 299 case RTM_GET: 300 case RTM_ADD: 301 case RTM_DELETE: 302 /* address related checks */ 303 sa = (struct sockaddr *)(rtm + 1); 304 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 305 if ((dst = rti_info[RTAX_DST]) == NULL || 306 dst->sa_family != AF_INET6) 307 continue; 308 309 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 310 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 311 continue; 312 313 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 314 gw->sa_family != AF_LINK) 315 continue; 316 if (ifindex && SDL(gw)->sdl_index != ifindex) 317 continue; 318 319 if (rti_info[RTAX_NETMASK] == NULL) 320 continue; 321 322 /* found */ 323 *lenp = rtm->rtm_msglen; 324 return (char *)rtm; 325 /* NOTREACHED */ 326 case RTM_NEWADDR: 327 case RTM_DELADDR: 328 ifam = (struct ifa_msghdr *)rtm; 329 330 /* address related checks */ 331 sa = (struct sockaddr *)(ifam + 1); 332 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 333 if ((ifa = rti_info[RTAX_IFA]) == NULL || 334 (ifa->sa_family != AF_INET && 335 ifa->sa_family != AF_INET6)) 336 continue; 337 338 if (ifa->sa_family == AF_INET6 && 339 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 340 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 341 continue; 342 343 if (ifindex && ifam->ifam_index != ifindex) 344 continue; 345 346 /* found */ 347 *lenp = ifam->ifam_msglen; 348 return (char *)rtm; 349 /* NOTREACHED */ 350 case RTM_IFINFO: 351 /* found */ 352 *lenp = rtm->rtm_msglen; 353 return (char *)rtm; 354 /* NOTREACHED */ 355 } 356 } 357 358 return (char *)rtm; 359 } 360 #undef FILTER_MATCH(type, filter) 361 362 struct in6_addr * 363 get_addr(char *buf) 364 { 365 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 366 struct sockaddr *sa, *rti_info[RTAX_MAX]; 367 368 sa = (struct sockaddr *)(rtm + 1); 369 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 370 371 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 372 } 373 374 int 375 get_rtm_ifindex(char *buf) 376 { 377 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 378 struct sockaddr *sa, *rti_info[RTAX_MAX]; 379 380 sa = (struct sockaddr *)(rtm + 1); 381 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 382 383 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 384 } 385 386 int 387 get_ifm_ifindex(char *buf) 388 { 389 struct if_msghdr *ifm = (struct if_msghdr *)buf; 390 391 return ((int)ifm->ifm_index); 392 } 393 394 int 395 get_ifam_ifindex(char *buf) 396 { 397 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 398 399 return ((int)ifam->ifam_index); 400 } 401 402 int 403 get_ifm_flags(char *buf) 404 { 405 struct if_msghdr *ifm = (struct if_msghdr *)buf; 406 407 return (ifm->ifm_flags); 408 } 409 410 int 411 get_prefixlen(char *buf) 412 { 413 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 414 struct sockaddr *sa, *rti_info[RTAX_MAX]; 415 u_char *p, *lim; 416 417 sa = (struct sockaddr *)(rtm + 1); 418 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 419 sa = rti_info[RTAX_NETMASK]; 420 421 p = (u_char *)(&SIN6(sa)->sin6_addr); 422 lim = (u_char *)sa + sa->sa_len; 423 return prefixlen(p, lim); 424 } 425 426 int 427 prefixlen(u_char *p, u_char *lim) 428 { 429 int masklen; 430 431 for (masklen = 0; p < lim; p++) { 432 switch (*p) { 433 case 0xff: 434 masklen += 8; 435 break; 436 case 0xfe: 437 masklen += 7; 438 break; 439 case 0xfc: 440 masklen += 6; 441 break; 442 case 0xf8: 443 masklen += 5; 444 break; 445 case 0xf0: 446 masklen += 4; 447 break; 448 case 0xe0: 449 masklen += 3; 450 break; 451 case 0xc0: 452 masklen += 2; 453 break; 454 case 0x80: 455 masklen += 1; 456 break; 457 case 0x00: 458 break; 459 default: 460 return(-1); 461 } 462 } 463 464 return(masklen); 465 } 466 467 int 468 rtmsg_type(char *buf) 469 { 470 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 471 472 return(rtm->rtm_type); 473 } 474 475 int 476 rtmsg_len(char *buf) 477 { 478 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 479 480 return(rtm->rtm_msglen); 481 } 482 483 int 484 ifmsg_len(char *buf) 485 { 486 struct if_msghdr *ifm = (struct if_msghdr *)buf; 487 488 return(ifm->ifm_msglen); 489 } 490 491 /* 492 * alloc buffer and get if_msghdrs block from kernel, 493 * and put them into the buffer 494 */ 495 static void 496 get_iflist(char **buf, size_t *size) 497 { 498 int mib[6]; 499 500 mib[0] = CTL_NET; 501 mib[1] = PF_ROUTE; 502 mib[2] = 0; 503 mib[3] = AF_INET6; 504 mib[4] = NET_RT_IFLIST; 505 mib[5] = 0; 506 507 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 508 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 509 __FUNCTION__); 510 exit(1); 511 } 512 if ((*buf = malloc(*size)) == NULL) { 513 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__); 514 exit(1); 515 } 516 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 517 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 518 __FUNCTION__); 519 exit(1); 520 } 521 return; 522 } 523 524 /* 525 * alloc buffer and parse if_msghdrs block passed as arg, 526 * and init the buffer as list of pointers ot each of the if_msghdr. 527 */ 528 static void 529 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 530 { 531 int iflentry_size, malloc_size; 532 struct if_msghdr *ifm; 533 struct ifa_msghdr *ifam; 534 char *lim; 535 536 /* 537 * Estimate least size of an iflist entry, to be obtained from kernel. 538 * Should add sizeof(sockaddr) ?? 539 */ 540 iflentry_size = sizeof(struct if_msghdr); 541 /* roughly estimate max list size of pointers to each if_msghdr */ 542 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 543 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 544 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__); 545 exit(1); 546 } 547 548 lim = buf + bufsize; 549 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 550 if (ifm->ifm_msglen == 0) { 551 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 552 "(buf=%p lim=%p ifm=%p)", __FUNCTION__, 553 buf, lim, ifm); 554 return; 555 } 556 557 if (ifm->ifm_type == RTM_IFINFO) { 558 (*ifmlist_p)[ifm->ifm_index] = ifm; 559 } else { 560 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 561 "expected %d, got %d\n msglen = %d\n" 562 "buf:%p, ifm:%p, lim:%p\n", 563 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 564 buf, ifm, lim); 565 exit (1); 566 } 567 for (ifam = (struct ifa_msghdr *) 568 ((char *)ifm + ifm->ifm_msglen); 569 ifam < (struct ifa_msghdr *)lim; 570 ifam = (struct ifa_msghdr *) 571 ((char *)ifam + ifam->ifam_msglen)) { 572 /* just for safety */ 573 if (!ifam->ifam_msglen) { 574 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 575 "(buf=%p lim=%p ifam=%p)", __FUNCTION__, 576 buf, lim, ifam); 577 return; 578 } 579 if (ifam->ifam_type != RTM_NEWADDR) 580 break; 581 } 582 ifm = (struct if_msghdr *)ifam; 583 } 584 } 585 586 void 587 init_iflist() 588 { 589 if (ifblock) { 590 free(ifblock); 591 ifblock_size = 0; 592 } 593 if (iflist) 594 free(iflist); 595 /* get iflist block from kernel */ 596 get_iflist(&ifblock, &ifblock_size); 597 598 /* make list of pointers to each if_msghdr */ 599 parse_iflist(&iflist, ifblock, ifblock_size); 600 } 601