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