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 * $DragonFly: src/usr.sbin/rtadvd/if.c,v 1.6 2005/12/05 00:56:37 swildner Exp $ 33 */ 34 35 #include <sys/param.h> 36 #include <sys/socket.h> 37 #include <sys/sysctl.h> 38 #include <sys/ioctl.h> 39 #include <net/if.h> 40 #include <net/if_types.h> 41 #ifdef __DragonFly__ 42 # include <net/ethernet.h> 43 #endif 44 #include <ifaddrs.h> 45 #ifdef __NetBSD__ 46 #include <net/if_ether.h> 47 #endif 48 #include <net/route.h> 49 #include <net/if_dl.h> 50 #include <netinet/in.h> 51 #include <netinet/icmp6.h> 52 #ifdef __bsdi__ 53 # include <netinet/if_ether.h> 54 #endif 55 #ifdef __OpenBSD__ 56 #include <netinet/if_ether.h> 57 #endif 58 #include <unistd.h> 59 #include <errno.h> 60 #include <stdlib.h> 61 #include <string.h> 62 #include <syslog.h> 63 #include "rtadvd.h" 64 #include "if.h" 65 66 #define ROUNDUP(a, size) \ 67 (((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a)) 68 69 #define NEXT_SA(ap) (ap) = (struct sockaddr *) \ 70 ((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\ 71 sizeof(u_long)) :\ 72 sizeof(u_long))) 73 74 struct if_msghdr **iflist; 75 int iflist_init_ok; 76 size_t ifblock_size; 77 char *ifblock; 78 79 static void get_iflist(char **buf, size_t *size); 80 static void parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, 81 size_t bufsize); 82 83 static void 84 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 85 { 86 int i; 87 88 for (i = 0; i < RTAX_MAX; i++) { 89 if (addrs & (1 << i)) { 90 rti_info[i] = sa; 91 NEXT_SA(sa); 92 } 93 else 94 rti_info[i] = NULL; 95 } 96 } 97 98 struct sockaddr_dl * 99 if_nametosdl(char *name) 100 { 101 int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0}; 102 char *buf, *next, *lim; 103 size_t len; 104 struct if_msghdr *ifm; 105 struct sockaddr *sa, *rti_info[RTAX_MAX]; 106 struct sockaddr_dl *sdl = NULL, *ret_sdl; 107 108 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 109 return(NULL); 110 if ((buf = malloc(len)) == NULL) 111 return(NULL); 112 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 113 free(buf); 114 return(NULL); 115 } 116 117 lim = buf + len; 118 for (next = buf; next < lim; next += ifm->ifm_msglen) { 119 ifm = (struct if_msghdr *)next; 120 if (ifm->ifm_type == RTM_IFINFO) { 121 sa = (struct sockaddr *)(ifm + 1); 122 get_rtaddrs(ifm->ifm_addrs, sa, rti_info); 123 if ((sa = rti_info[RTAX_IFP]) != NULL) { 124 if (sa->sa_family == AF_LINK) { 125 sdl = (struct sockaddr_dl *)sa; 126 if (strlen(name) != sdl->sdl_nlen) 127 continue; /* not same len */ 128 if (strncmp(&sdl->sdl_data[0], 129 name, 130 sdl->sdl_nlen) == 0) { 131 break; 132 } 133 } 134 } 135 } 136 } 137 if (next == lim) { 138 /* search failed */ 139 free(buf); 140 return(NULL); 141 } 142 143 if ((ret_sdl = malloc(sdl->sdl_len)) == NULL) 144 return(NULL); 145 memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len); 146 return(ret_sdl); 147 } 148 149 int 150 if_getmtu(char *name) 151 { 152 struct ifaddrs *ifap, *ifa; 153 struct if_data *ifd; 154 u_long mtu = 0; 155 156 if (getifaddrs(&ifap) < 0) 157 return(0); 158 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 159 if (strcmp(ifa->ifa_name, name) == 0) { 160 ifd = ifa->ifa_data; 161 if (ifd) 162 mtu = ifd->ifi_mtu; 163 break; 164 } 165 } 166 freeifaddrs(ifap); 167 168 #ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 169 if (mtu == 0) { 170 struct ifreq ifr; 171 int s; 172 173 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 174 return(0); 175 176 ifr.ifr_addr.sa_family = AF_INET6; 177 strncpy(ifr.ifr_name, name, 178 sizeof(ifr.ifr_name)); 179 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 180 close(s); 181 return(0); 182 } 183 close(s); 184 185 mtu = ifr.ifr_mtu; 186 } 187 #endif 188 189 return(mtu); 190 } 191 192 /* give interface index and its old flags, then new flags returned */ 193 int 194 if_getflags(int ifindex, int oifflags) 195 { 196 struct ifreq ifr; 197 int s; 198 199 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 200 syslog(LOG_ERR, "<%s> socket: %s", __func__, 201 strerror(errno)); 202 return (oifflags & ~IFF_UP); 203 } 204 205 if_indextoname(ifindex, ifr.ifr_name); 206 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 207 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 208 __func__, ifr.ifr_name); 209 close(s); 210 return (oifflags & ~IFF_UP); 211 } 212 close(s); 213 return (ifr.ifr_flags); 214 } 215 216 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 217 int 218 lladdropt_length(struct sockaddr_dl *sdl) 219 { 220 switch(sdl->sdl_type) { 221 case IFT_ETHER: 222 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 223 default: 224 return(0); 225 } 226 } 227 228 void 229 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 230 { 231 char *addr; 232 233 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 234 235 switch(sdl->sdl_type) { 236 case IFT_ETHER: 237 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 238 addr = (char *)(ndopt + 1); 239 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 240 break; 241 default: 242 syslog(LOG_ERR, 243 "<%s> unsupported link type(%d)", 244 __func__, sdl->sdl_type); 245 exit(1); 246 } 247 248 return; 249 } 250 251 int 252 rtbuf_len(void) 253 { 254 size_t len; 255 256 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 257 258 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 259 return(-1); 260 261 return(len); 262 } 263 264 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 265 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 266 #define SDL(s) ((struct sockaddr_dl *)(s)) 267 char * 268 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 269 { 270 struct rt_msghdr *rtm; 271 struct ifa_msghdr *ifam; 272 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 273 274 *lenp = 0; 275 for (rtm = (struct rt_msghdr *)buf; 276 rtm < (struct rt_msghdr *)lim; 277 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 278 /* just for safety */ 279 if (!rtm->rtm_msglen) { 280 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 281 "(buf=%p lim=%p rtm=%p)", __func__, 282 buf, lim, rtm); 283 break; 284 } 285 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 286 continue; 287 } 288 289 switch (rtm->rtm_type) { 290 case RTM_GET: 291 case RTM_ADD: 292 case RTM_DELETE: 293 /* address related checks */ 294 sa = (struct sockaddr *)(rtm + 1); 295 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 296 if ((dst = rti_info[RTAX_DST]) == NULL || 297 dst->sa_family != AF_INET6) 298 continue; 299 300 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 301 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 302 continue; 303 304 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 305 gw->sa_family != AF_LINK) 306 continue; 307 if (ifindex && SDL(gw)->sdl_index != ifindex) 308 continue; 309 310 if (rti_info[RTAX_NETMASK] == NULL) 311 continue; 312 313 /* found */ 314 *lenp = rtm->rtm_msglen; 315 return (char *)rtm; 316 /* NOTREACHED */ 317 case RTM_NEWADDR: 318 case RTM_DELADDR: 319 ifam = (struct ifa_msghdr *)rtm; 320 321 /* address related checks */ 322 sa = (struct sockaddr *)(ifam + 1); 323 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 324 if ((ifa = rti_info[RTAX_IFA]) == NULL || 325 (ifa->sa_family != AF_INET && 326 ifa->sa_family != AF_INET6)) 327 continue; 328 329 if (ifa->sa_family == AF_INET6 && 330 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 331 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 332 continue; 333 334 if (ifindex && ifam->ifam_index != ifindex) 335 continue; 336 337 /* found */ 338 *lenp = ifam->ifam_msglen; 339 return (char *)rtm; 340 /* NOTREACHED */ 341 case RTM_IFINFO: 342 /* found */ 343 *lenp = rtm->rtm_msglen; 344 return (char *)rtm; 345 /* NOTREACHED */ 346 } 347 } 348 349 return (char *)rtm; 350 } 351 #undef FILTER_MATCH 352 353 struct in6_addr * 354 get_addr(char *buf) 355 { 356 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 357 struct sockaddr *sa, *rti_info[RTAX_MAX]; 358 359 sa = (struct sockaddr *)(rtm + 1); 360 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 361 362 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 363 } 364 365 int 366 get_rtm_ifindex(char *buf) 367 { 368 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 369 struct sockaddr *sa, *rti_info[RTAX_MAX]; 370 371 sa = (struct sockaddr *)(rtm + 1); 372 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 373 374 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 375 } 376 377 int 378 get_ifm_ifindex(char *buf) 379 { 380 struct if_msghdr *ifm = (struct if_msghdr *)buf; 381 382 return ((int)ifm->ifm_index); 383 } 384 385 int 386 get_ifam_ifindex(char *buf) 387 { 388 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 389 390 return ((int)ifam->ifam_index); 391 } 392 393 int 394 get_ifm_flags(char *buf) 395 { 396 struct if_msghdr *ifm = (struct if_msghdr *)buf; 397 398 return (ifm->ifm_flags); 399 } 400 401 int 402 get_prefixlen(char *buf) 403 { 404 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 405 struct sockaddr *sa, *rti_info[RTAX_MAX]; 406 u_char *p, *lim; 407 408 sa = (struct sockaddr *)(rtm + 1); 409 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 410 sa = rti_info[RTAX_NETMASK]; 411 412 p = (u_char *)(&SIN6(sa)->sin6_addr); 413 lim = (u_char *)sa + sa->sa_len; 414 return prefixlen(p, lim); 415 } 416 417 int 418 prefixlen(u_char *p, u_char *lim) 419 { 420 int masklen; 421 422 for (masklen = 0; p < lim; p++) { 423 switch (*p) { 424 case 0xff: 425 masklen += 8; 426 break; 427 case 0xfe: 428 masklen += 7; 429 break; 430 case 0xfc: 431 masklen += 6; 432 break; 433 case 0xf8: 434 masklen += 5; 435 break; 436 case 0xf0: 437 masklen += 4; 438 break; 439 case 0xe0: 440 masklen += 3; 441 break; 442 case 0xc0: 443 masklen += 2; 444 break; 445 case 0x80: 446 masklen += 1; 447 break; 448 case 0x00: 449 break; 450 default: 451 return(-1); 452 } 453 } 454 455 return(masklen); 456 } 457 458 int 459 rtmsg_type(char *buf) 460 { 461 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 462 463 return(rtm->rtm_type); 464 } 465 466 int 467 rtmsg_len(char *buf) 468 { 469 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 470 471 return(rtm->rtm_msglen); 472 } 473 474 int 475 ifmsg_len(char *buf) 476 { 477 struct if_msghdr *ifm = (struct if_msghdr *)buf; 478 479 return(ifm->ifm_msglen); 480 } 481 482 /* 483 * alloc buffer and get if_msghdrs block from kernel, 484 * and put them into the buffer 485 */ 486 static void 487 get_iflist(char **buf, size_t *size) 488 { 489 int mib[6]; 490 491 mib[0] = CTL_NET; 492 mib[1] = PF_ROUTE; 493 mib[2] = 0; 494 mib[3] = AF_INET6; 495 mib[4] = NET_RT_IFLIST; 496 mib[5] = 0; 497 498 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 499 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 500 __func__); 501 exit(1); 502 } 503 if ((*buf = malloc(*size)) == NULL) { 504 syslog(LOG_ERR, "<%s> malloc failed", __func__); 505 exit(1); 506 } 507 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 508 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 509 __func__); 510 exit(1); 511 } 512 return; 513 } 514 515 /* 516 * alloc buffer and parse if_msghdrs block passed as arg, 517 * and init the buffer as list of pointers ot each of the if_msghdr. 518 */ 519 static void 520 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 521 { 522 int iflentry_size, malloc_size; 523 struct if_msghdr *ifm; 524 struct ifa_msghdr *ifam; 525 char *lim; 526 527 /* 528 * Estimate least size of an iflist entry, to be obtained from kernel. 529 * Should add sizeof(sockaddr) ?? 530 */ 531 iflentry_size = sizeof(struct if_msghdr); 532 /* roughly estimate max list size of pointers to each if_msghdr */ 533 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 534 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 535 syslog(LOG_ERR, "<%s> malloc failed", __func__); 536 exit(1); 537 } 538 539 lim = buf + bufsize; 540 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 541 if (ifm->ifm_msglen == 0) { 542 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 543 "(buf=%p lim=%p ifm=%p)", __func__, 544 buf, lim, ifm); 545 return; 546 } 547 548 if (ifm->ifm_type == RTM_IFINFO) { 549 (*ifmlist_p)[ifm->ifm_index] = ifm; 550 } else { 551 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 552 "expected %d, got %d\n msglen = %d\n" 553 "buf:%p, ifm:%p, lim:%p\n", 554 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 555 buf, ifm, lim); 556 exit (1); 557 } 558 for (ifam = (struct ifa_msghdr *) 559 ((char *)ifm + ifm->ifm_msglen); 560 ifam < (struct ifa_msghdr *)lim; 561 ifam = (struct ifa_msghdr *) 562 ((char *)ifam + ifam->ifam_msglen)) { 563 /* just for safety */ 564 if (!ifam->ifam_msglen) { 565 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 566 "(buf=%p lim=%p ifam=%p)", __func__, 567 buf, lim, ifam); 568 return; 569 } 570 if (ifam->ifam_type != RTM_NEWADDR) 571 break; 572 } 573 ifm = (struct if_msghdr *)ifam; 574 } 575 } 576 577 void 578 init_iflist(void) 579 { 580 if (ifblock) { 581 free(ifblock); 582 ifblock_size = 0; 583 } 584 if (iflist) 585 free(iflist); 586 /* get iflist block from kernel */ 587 get_iflist(&ifblock, &ifblock_size); 588 589 /* make list of pointers to each if_msghdr */ 590 parse_iflist(&iflist, ifblock, ifblock_size); 591 } 592