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 32#include <sys/param.h> 33#include <sys/socket.h> 34#include <sys/sysctl.h> 35#include <sys/ioctl.h> 36#include <net/if.h> 37#include <net/if_types.h> 38#include <net/ethernet.h> 39#include <ifaddrs.h> 40#include <net/route.h> 41#include <net/if_dl.h> 42#include <netinet/in.h> 43#include <netinet/icmp6.h> 44#include <unistd.h> 45#include <errno.h> 46#include <stdlib.h> 47#include <string.h> 48#include <syslog.h> 49#include "rtadvd.h" 50#include "if.h" 51 52#define ROUNDUP(a, size) \ 53 (((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a)) 54 55#define NEXT_SA(ap) (ap) = (struct sockaddr *) \ 56 ((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\ 57 sizeof(uint32_t)) :\ 58 sizeof(uint32_t))) 59 60struct if_msghdr **iflist; 61int iflist_init_ok; 62size_t ifblock_size; 63char *ifblock; 64 65static void get_iflist(char **buf, size_t *size); 66static void parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, 67 size_t bufsize); 68 69static void 70get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 71{ 72 int i; 73 74 for (i = 0; i < RTAX_MAX; i++) { 75 if (addrs & (1 << i)) { 76 rti_info[i] = sa; 77 NEXT_SA(sa); 78 } 79 else 80 rti_info[i] = NULL; 81 } 82} 83 84struct sockaddr_dl * 85if_nametosdl(char *name) 86{ 87 int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0}; 88 char *buf, *next, *lim; 89 size_t len; 90 struct if_msghdr *ifm; 91 struct sockaddr *sa, *rti_info[RTAX_MAX]; 92 struct sockaddr_dl *sdl = NULL, *ret_sdl; 93 94 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 95 return(NULL); 96 if ((buf = malloc(len)) == NULL) 97 return(NULL); 98 if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) { 99 free(buf); 100 return(NULL); 101 } 102 103 lim = buf + len; 104 for (next = buf; next < lim; next += ifm->ifm_msglen) { 105 ifm = (struct if_msghdr *)next; 106 if (ifm->ifm_type == RTM_IFINFO) { 107 sa = (struct sockaddr *)(ifm + 1); 108 get_rtaddrs(ifm->ifm_addrs, sa, rti_info); 109 if ((sa = rti_info[RTAX_IFP]) != NULL) { 110 if (sa->sa_family == AF_LINK) { 111 sdl = (struct sockaddr_dl *)sa; 112 if (strlen(name) != sdl->sdl_nlen) 113 continue; /* not same len */ 114 if (strncmp(&sdl->sdl_data[0], 115 name, 116 sdl->sdl_nlen) == 0) { 117 break; 118 } 119 } 120 } 121 } 122 } 123 if (next == lim) { 124 /* search failed */ 125 free(buf); 126 return(NULL); 127 } 128 129 if ((ret_sdl = malloc(sdl->sdl_len)) == NULL) 130 goto end; 131 memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len); 132 133end: 134 free(buf); 135 return(ret_sdl); 136} 137 138int 139if_getmtu(char *name) 140{ 141 struct ifaddrs *ifap, *ifa; 142 struct if_data *ifd; 143 int mtu = 0; 144 145 if (getifaddrs(&ifap) < 0) 146 return(0); 147 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 148 if (strcmp(ifa->ifa_name, name) == 0) { 149 ifd = ifa->ifa_data; 150 if (ifd) 151 mtu = ifd->ifi_mtu; 152 break; 153 } 154 } 155 freeifaddrs(ifap); 156 157#ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */ 158 if (mtu == 0) { 159 struct ifreq ifr; 160 int s; 161 162 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 163 return(0); 164 165 ifr.ifr_addr.sa_family = AF_INET6; 166 strncpy(ifr.ifr_name, name, 167 sizeof(ifr.ifr_name)); 168 if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) { 169 close(s); 170 return(0); 171 } 172 close(s); 173 174 mtu = ifr.ifr_mtu; 175 } 176#endif 177 178 return(mtu); 179} 180 181/* give interface index and its old flags, then new flags returned */ 182int 183if_getflags(int ifindex, int oifflags) 184{ 185 struct ifreq ifr; 186 int s; 187 188 if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 189 syslog(LOG_ERR, "<%s> socket: %s", __func__, 190 strerror(errno)); 191 return (oifflags & ~IFF_UP); 192 } 193 194 if_indextoname(ifindex, ifr.ifr_name); 195 if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) { 196 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 197 __func__, ifr.ifr_name); 198 close(s); 199 return (oifflags & ~IFF_UP); 200 } 201 close(s); 202 return (ifr.ifr_flags); 203} 204 205#define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 206int 207lladdropt_length(struct sockaddr_dl *sdl) 208{ 209 switch (sdl->sdl_type) { 210 case IFT_ETHER: 211 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 212 default: 213 return(0); 214 } 215} 216 217void 218lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 219{ 220 char *addr; 221 222 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 223 224 switch (sdl->sdl_type) { 225 case IFT_ETHER: 226 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 227 addr = (char *)(ndopt + 1); 228 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 229 break; 230 default: 231 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 232 __func__, sdl->sdl_type); 233 exit(1); 234 } 235 236 return; 237} 238 239int 240rtbuf_len() 241{ 242 size_t len; 243 244 int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0}; 245 246 if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0) 247 return(-1); 248 249 return(len); 250} 251 252#define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 253#define SIN6(s) ((struct sockaddr_in6 *)(s)) 254#define SDL(s) ((struct sockaddr_dl *)(s)) 255char * 256get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 257{ 258 struct rt_msghdr *rtm; 259 struct ifa_msghdr *ifam; 260 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 261 262 *lenp = 0; 263 for (rtm = (struct rt_msghdr *)buf; 264 rtm < (struct rt_msghdr *)lim; 265 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 266 /* just for safety */ 267 if (!rtm->rtm_msglen) { 268 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 269 "(buf=%p lim=%p rtm=%p)", __func__, 270 buf, lim, rtm); 271 break; 272 } 273 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 274 continue; 275 } 276 277 switch (rtm->rtm_type) { 278 case RTM_GET: 279 case RTM_ADD: 280 case RTM_DELETE: 281 /* address related checks */ 282 sa = (struct sockaddr *)(rtm + 1); 283 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 284 if ((dst = rti_info[RTAX_DST]) == NULL || 285 dst->sa_family != AF_INET6) 286 continue; 287 288 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 289 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 290 continue; 291 292 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 293 gw->sa_family != AF_LINK) 294 continue; 295 if (ifindex && SDL(gw)->sdl_index != ifindex) 296 continue; 297 298 if (rti_info[RTAX_NETMASK] == NULL) 299 continue; 300 301 /* found */ 302 *lenp = rtm->rtm_msglen; 303 return (char *)rtm; 304 /* NOTREACHED */ 305 case RTM_NEWADDR: 306 case RTM_DELADDR: 307 ifam = (struct ifa_msghdr *)rtm; 308 309 /* address related checks */ 310 sa = (struct sockaddr *)(ifam + 1); 311 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 312 if ((ifa = rti_info[RTAX_IFA]) == NULL || 313 (ifa->sa_family != AF_INET && 314 ifa->sa_family != AF_INET6)) 315 continue; 316 317 if (ifa->sa_family == AF_INET6 && 318 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 319 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 320 continue; 321 322 if (ifindex && ifam->ifam_index != ifindex) 323 continue; 324 325 /* found */ 326 *lenp = ifam->ifam_msglen; 327 return (char *)rtm; 328 /* NOTREACHED */ 329 case RTM_IFINFO: 330 /* found */ 331 *lenp = rtm->rtm_msglen; 332 return (char *)rtm; 333 /* NOTREACHED */ 334 } 335 } 336 337 return (char *)rtm; 338} 339#undef FILTER_MATCH 340 341struct in6_addr * 342get_addr(char *buf) 343{ 344 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 345 struct sockaddr *sa, *rti_info[RTAX_MAX]; 346 347 sa = (struct sockaddr *)(rtm + 1); 348 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 349 350 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 351} 352 353int 354get_rtm_ifindex(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(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 363} 364 365int 366get_ifm_ifindex(char *buf) 367{ 368 struct if_msghdr *ifm = (struct if_msghdr *)buf; 369 370 return ((int)ifm->ifm_index); 371} 372 373int 374get_ifam_ifindex(char *buf) 375{ 376 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 377 378 return ((int)ifam->ifam_index); 379} 380 381int 382get_ifm_flags(char *buf) 383{ 384 struct if_msghdr *ifm = (struct if_msghdr *)buf; 385 386 return (ifm->ifm_flags); 387} 388 389int 390get_prefixlen(char *buf) 391{ 392 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 393 struct sockaddr *sa, *rti_info[RTAX_MAX]; 394 u_char *p, *lim; 395 396 sa = (struct sockaddr *)(rtm + 1); 397 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 398 sa = rti_info[RTAX_NETMASK]; 399 400 p = (u_char *)(&SIN6(sa)->sin6_addr); 401 lim = (u_char *)sa + sa->sa_len; 402 return prefixlen(p, lim); 403} 404 405int 406prefixlen(u_char *p, u_char *lim) 407{ 408 int masklen; 409 410 for (masklen = 0; p < lim; p++) { 411 switch (*p) { 412 case 0xff: 413 masklen += 8; 414 break; 415 case 0xfe: 416 masklen += 7; 417 break; 418 case 0xfc: 419 masklen += 6; 420 break; 421 case 0xf8: 422 masklen += 5; 423 break; 424 case 0xf0: 425 masklen += 4; 426 break; 427 case 0xe0: 428 masklen += 3; 429 break; 430 case 0xc0: 431 masklen += 2; 432 break; 433 case 0x80: 434 masklen += 1; 435 break; 436 case 0x00: 437 break; 438 default: 439 return(-1); 440 } 441 } 442 443 return(masklen); 444} 445 446int 447rtmsg_type(char *buf) 448{ 449 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 450 451 return(rtm->rtm_type); 452} 453 454int 455rtmsg_len(char *buf) 456{ 457 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 458 459 return(rtm->rtm_msglen); 460} 461 462int 463ifmsg_len(char *buf) 464{ 465 struct if_msghdr *ifm = (struct if_msghdr *)buf; 466 467 return(ifm->ifm_msglen); 468} 469 470/* 471 * alloc buffer and get if_msghdrs block from kernel, 472 * and put them into the buffer 473 */ 474static void 475get_iflist(char **buf, size_t *size) 476{ 477 int mib[6]; 478 479 mib[0] = CTL_NET; 480 mib[1] = PF_ROUTE; 481 mib[2] = 0; 482 mib[3] = AF_INET6; 483 mib[4] = NET_RT_IFLIST; 484 mib[5] = 0; 485 486 if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) { 487 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed", 488 __func__); 489 exit(1); 490 } 491 if ((*buf = malloc(*size)) == NULL) { 492 syslog(LOG_ERR, "<%s> malloc failed", __func__); 493 exit(1); 494 } 495 if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) { 496 syslog(LOG_ERR, "<%s> sysctl: iflist get failed", 497 __func__); 498 exit(1); 499 } 500 return; 501} 502 503/* 504 * alloc buffer and parse if_msghdrs block passed as arg, 505 * and init the buffer as list of pointers ot each of the if_msghdr. 506 */ 507static void 508parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize) 509{ 510 int iflentry_size, malloc_size; 511 struct if_msghdr *ifm; 512 struct ifa_msghdr *ifam; 513 char *lim; 514 515 /* 516 * Estimate least size of an iflist entry, to be obtained from kernel. 517 * Should add sizeof(sockaddr) ?? 518 */ 519 iflentry_size = sizeof(struct if_msghdr); 520 /* roughly estimate max list size of pointers to each if_msghdr */ 521 malloc_size = (bufsize/iflentry_size) * sizeof(size_t); 522 if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) { 523 syslog(LOG_ERR, "<%s> malloc failed", __func__); 524 exit(1); 525 } 526 527 lim = buf + bufsize; 528 for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) { 529 if (ifm->ifm_msglen == 0) { 530 syslog(LOG_WARNING, "<%s> ifm_msglen is 0 " 531 "(buf=%p lim=%p ifm=%p)", __func__, 532 buf, lim, ifm); 533 return; 534 } 535 536 if (ifm->ifm_type == RTM_IFINFO) { 537 (*ifmlist_p)[ifm->ifm_index] = ifm; 538 } else { 539 syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n" 540 "expected %d, got %d\n msglen = %d\n" 541 "buf:%p, ifm:%p, lim:%p\n", 542 RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen, 543 buf, ifm, lim); 544 exit (1); 545 } 546 for (ifam = (struct ifa_msghdr *) 547 ((char *)ifm + ifm->ifm_msglen); 548 ifam < (struct ifa_msghdr *)lim; 549 ifam = (struct ifa_msghdr *) 550 ((char *)ifam + ifam->ifam_msglen)) { 551 /* just for safety */ 552 if (!ifam->ifam_msglen) { 553 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 " 554 "(buf=%p lim=%p ifam=%p)", __func__, 555 buf, lim, ifam); 556 return; 557 } 558 if (ifam->ifam_type != RTM_NEWADDR) 559 break; 560 } 561 ifm = (struct if_msghdr *)ifam; 562 } 563} 564 565void 566init_iflist() 567{ 568 if (ifblock) { 569 free(ifblock); 570 ifblock_size = 0; 571 } 572 if (iflist) 573 free(iflist); 574 /* get iflist block from kernel */ 575 get_iflist(&ifblock, &ifblock_size); 576 577 /* make list of pointers to each if_msghdr */ 578 parse_iflist(&iflist, ifblock, ifblock_size); 579} 580