1 /* $KAME: if.c,v 1.14 2000/10/25 04:28:34 jinmei 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 * $FreeBSD$ 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 int 264 get_rtinfo(char *buf, size_t *len) 265 { 266 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 267 268 if (sysctl(mib, 6, buf, len, NULL, 0) < 0) 269 return(-1); 270 271 return(0); 272 } 273 274 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 275 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 276 #define SDL(s) ((struct sockaddr_dl *)(s)) 277 char * 278 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 279 { 280 struct rt_msghdr *rtm; 281 struct ifa_msghdr *ifam; 282 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 283 284 *lenp = 0; 285 for (rtm = (struct rt_msghdr *)buf; 286 rtm < (struct rt_msghdr *)lim; 287 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 288 /* just for safety */ 289 if (!rtm->rtm_msglen) { 290 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 291 "(buf=%p lim=%p rtm=%p)", __FUNCTION__, 292 buf, lim, rtm); 293 break; 294 } 295 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 296 continue; 297 } 298 299 switch (rtm->rtm_type) { 300 case RTM_GET: 301 case RTM_ADD: 302 case RTM_DELETE: 303 /* address related checks */ 304 sa = (struct sockaddr *)(rtm + 1); 305 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 306 if ((dst = rti_info[RTAX_DST]) == NULL || 307 dst->sa_family != AF_INET6) 308 continue; 309 310 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 311 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 312 continue; 313 314 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 315 gw->sa_family != AF_LINK) 316 continue; 317 if (ifindex && SDL(gw)->sdl_index != ifindex) 318 continue; 319 320 if (rti_info[RTAX_NETMASK] == NULL) 321 continue; 322 323 /* found */ 324 *lenp = rtm->rtm_msglen; 325 return (char *)rtm; 326 /* NOTREACHED */ 327 case RTM_NEWADDR: 328 case RTM_DELADDR: 329 ifam = (struct ifa_msghdr *)rtm; 330 331 /* address related checks */ 332 sa = (struct sockaddr *)(ifam + 1); 333 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 334 if ((ifa = rti_info[RTAX_IFA]) == NULL || 335 (ifa->sa_family != AF_INET && 336 ifa->sa_family != AF_INET6)) 337 continue; 338 339 if (ifa->sa_family == AF_INET6 && 340 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 341 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 342 continue; 343 344 if (ifindex && ifam->ifam_index != ifindex) 345 continue; 346 347 /* found */ 348 *lenp = ifam->ifam_msglen; 349 return (char *)rtm; 350 /* NOTREACHED */ 351 case RTM_IFINFO: 352 /* found */ 353 *lenp = rtm->rtm_msglen; 354 return (char *)rtm; 355 /* NOTREACHED */ 356 } 357 } 358 359 return (char *)rtm; 360 } 361 #undef FILTER_MATCH(type, filter) 362 363 struct in6_addr * 364 get_addr(char *buf) 365 { 366 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 367 struct sockaddr *sa, *rti_info[RTAX_MAX]; 368 369 sa = (struct sockaddr *)(rtm + 1); 370 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 371 372 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 373 } 374 375 int 376 get_rtm_ifindex(char *buf) 377 { 378 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 379 struct sockaddr *sa, *rti_info[RTAX_MAX]; 380 381 sa = (struct sockaddr *)(rtm + 1); 382 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 383 384 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 385 } 386 387 int 388 get_ifm_ifindex(char *buf) 389 { 390 struct if_msghdr *ifm = (struct if_msghdr *)buf; 391 392 return ((int)ifm->ifm_index); 393 } 394 395 int 396 get_ifam_ifindex(char *buf) 397 { 398 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 399 400 return ((int)ifam->ifam_index); 401 } 402 403 int 404 get_ifm_flags(char *buf) 405 { 406 struct if_msghdr *ifm = (struct if_msghdr *)buf; 407 408 return (ifm->ifm_flags); 409 } 410 411 int 412 get_prefixlen(char *buf) 413 { 414 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 415 struct sockaddr *sa, *rti_info[RTAX_MAX]; 416 u_char *p, *lim; 417 418 sa = (struct sockaddr *)(rtm + 1); 419 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 420 sa = rti_info[RTAX_NETMASK]; 421 422 p = (u_char *)(&SIN6(sa)->sin6_addr); 423 lim = (u_char *)sa + sa->sa_len; 424 return prefixlen(p, lim); 425 } 426 427 int 428 prefixlen(u_char *p, u_char *lim) 429 { 430 int masklen; 431 432 for (masklen = 0; p < lim; p++) { 433 switch (*p) { 434 case 0xff: 435 masklen += 8; 436 break; 437 case 0xfe: 438 masklen += 7; 439 break; 440 case 0xfc: 441 masklen += 6; 442 break; 443 case 0xf8: 444 masklen += 5; 445 break; 446 case 0xf0: 447 masklen += 4; 448 break; 449 case 0xe0: 450 masklen += 3; 451 break; 452 case 0xc0: 453 masklen += 2; 454 break; 455 case 0x80: 456 masklen += 1; 457 break; 458 case 0x00: 459 break; 460 default: 461 return(-1); 462 } 463 } 464 465 return(masklen); 466 } 467 468 int 469 rtmsg_type(char *buf) 470 { 471 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 472 473 return(rtm->rtm_type); 474 } 475 476 int 477 rtmsg_len(char *buf) 478 { 479 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 480 481 return(rtm->rtm_msglen); 482 } 483 484 int 485 ifmsg_len(char *buf) 486 { 487 struct if_msghdr *ifm = (struct if_msghdr *)buf; 488 489 return(ifm->ifm_msglen); 490 } 491 492 /* 493 * alloc buffer and get if_msghdrs block from kernel, 494 * and put them into the buffer 495 */ 496 static void 497 get_iflist(char **buf, size_t *size) 498 { 499 int mib[6]; 500 501 mib[0] = CTL_NET; 502 mib[1] = PF_ROUTE; 503 mib[2] = 0; 504 mib[3] = AF_INET6; 505 mib[4] = NET_RT_IFLIST; 506 mib[5] = 0; 507 508 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 509 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 510 __FUNCTION__); 511 exit(1); 512 } 513 if ((*buf = malloc(*size)) == NULL) { 514 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__); 515 exit(1); 516 } 517 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 518 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 519 __FUNCTION__); 520 exit(1); 521 } 522 return; 523 } 524 525 /* 526 * alloc buffer and parse if_msghdrs block passed as arg, 527 * and init the buffer as list of pointers ot each of the if_msghdr. 528 */ 529 static void 530 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 531 { 532 int iflentry_size, malloc_size; 533 struct if_msghdr *ifm; 534 struct ifa_msghdr *ifam; 535 char *lim; 536 537 /* 538 * Estimate least size of an iflist entry, to be obtained from kernel. 539 * Should add sizeof(sockaddr) ?? 540 */ 541 iflentry_size = sizeof(struct if_msghdr); 542 /* roughly estimate max list size of pointers to each if_msghdr */ 543 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 544 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 545 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__); 546 exit(1); 547 } 548 549 lim = buf + bufsize; 550 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 551 if (ifm->ifm_msglen == 0) { 552 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 553 "(buf=%p lim=%p ifm=%p)", __FUNCTION__, 554 buf, lim, ifm); 555 return; 556 } 557 558 if (ifm->ifm_type == RTM_IFINFO) { 559 (*ifmlist_p)[ifm->ifm_index] = ifm; 560 } else { 561 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 562 "expected %d, got %d\n msglen = %d\n" 563 "buf:%p, ifm:%p, lim:%p\n", 564 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 565 buf, ifm, lim); 566 exit (1); 567 } 568 for (ifam = (struct ifa_msghdr *) 569 ((char *)ifm + ifm->ifm_msglen); 570 ifam < (struct ifa_msghdr *)lim; 571 ifam = (struct ifa_msghdr *) 572 ((char *)ifam + ifam->ifam_msglen)) { 573 /* just for safety */ 574 if (!ifam->ifam_msglen) { 575 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 576 "(buf=%p lim=%p ifam=%p)", __FUNCTION__, 577 buf, lim, ifam); 578 return; 579 } 580 if (ifam->ifam_type != RTM_NEWADDR) 581 break; 582 } 583 ifm = (struct if_msghdr *)ifam; 584 } 585 } 586 587 void 588 init_iflist() 589 { 590 if (ifblock) { 591 free(ifblock); 592 ifblock_size = 0; 593 } 594 if (iflist) 595 free(iflist); 596 /* get iflist block from kernel */ 597 get_iflist(&ifblock, &ifblock_size); 598 599 /* make list of pointers to each if_msghdr */ 600 parse_iflist(&iflist, ifblock, ifblock_size); 601 } 602