usr.sbin/rtadvd/if.c

   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 }