rtadvd.tproj/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  */
  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 #if defined(__FreeBSD__) || defined (__APPLE__)
  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(uint32_t)) :\
  71                                                  sizeof(uint32_t)))
  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 = NULL;
 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                 goto end;
 113
 114         lim = buf + len;
 115         for (next = buf; next < lim; next += ifm->ifm_msglen) {
 116                 ifm = (struct if_msghdr *)next;
 117                 if (ifm->ifm_type == RTM_IFINFO) {
 118                         sa = (struct sockaddr *)(ifm + 1);
 119                         get_rtaddrs(ifm->ifm_addrs, sa, rti_info);
 120                         if ((sa = rti_info[RTAX_IFP]) != NULL) {
 121                                 if (sa->sa_family == AF_LINK) {
 122                                         sdl = (struct sockaddr_dl *)sa;
 123                                         if (strlen(name) != sdl->sdl_nlen)
 124                                                 continue; /* not same len */
 125                                         if (strncmp(&sdl->sdl_data[0],
 126                                                     name,
 127                                                     sdl->sdl_nlen) == 0) {
 128                                                 break;
 129                                         }
 130                                 }
 131                         }
 132                 }
 133         }
 134         if (next == lim) {
 135                 /* search failed */
 136                 goto end;
 137         }
 138
 139         if ((ret_sdl = malloc(sdl->sdl_len)) == NULL)
 140                 goto end;
 141         memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len);
 142
 143 end:
 144         free(buf);
 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         int 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 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter)
 264 #define SIN6(s) ((struct sockaddr_in6 *)(s))
 265 #define SDL(s) ((struct sockaddr_dl *)(s))
 266 char *
 267 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter)
 268 {
 269         struct rt_msghdr *rtm;
 270         struct ifa_msghdr *ifam;
 271         struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX];
 272
 273         *lenp = 0;
 274         for (rtm = (struct rt_msghdr *)buf;
 275              rtm < (struct rt_msghdr *)lim;
 276              rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) {
 277                 /* just for safety */
 278                 if (!rtm->rtm_msglen) {
 279                         syslog(LOG_WARNING, "<%s> rtm_msglen is 0 "
 280                                 "(buf=%p lim=%p rtm=%p)", __FUNCTION__,
 281                                 buf, lim, rtm);
 282                         break;
 283                 }
 284                 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) {
 285                         continue;
 286                 }
 287
 288                 switch (rtm->rtm_type) {
 289                 case RTM_GET:
 290                 case RTM_ADD:
 291                 case RTM_DELETE:
 292                         /* address related checks */
 293                         sa = (struct sockaddr *)(rtm + 1);
 294                         get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
 295                         if ((dst = rti_info[RTAX_DST]) == NULL ||
 296                             dst->sa_family != AF_INET6)
 297                                 continue;
 298
 299                         if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) ||
 300                             IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr))
 301                                 continue;
 302
 303                         if ((gw = rti_info[RTAX_GATEWAY]) == NULL ||
 304                             gw->sa_family != AF_LINK)
 305                                 continue;
 306                         if (ifindex && SDL(gw)->sdl_index != ifindex)
 307                                 continue;
 308
 309                         if (rti_info[RTAX_NETMASK] == NULL)
 310                                 continue;
 311
 312                         /* found */
 313                         *lenp = rtm->rtm_msglen;
 314                         return (char *)rtm;
 315                         /* NOTREACHED */
 316                 case RTM_NEWADDR:
 317                 case RTM_DELADDR:
 318                         ifam = (struct ifa_msghdr *)rtm;
 319
 320                         /* address related checks */
 321                         sa = (struct sockaddr *)(ifam + 1);
 322                         get_rtaddrs(ifam->ifam_addrs, sa, rti_info);
 323                         if ((ifa = rti_info[RTAX_IFA]) == NULL ||
 324                             (ifa->sa_family != AF_INET &&
 325                              ifa->sa_family != AF_INET6))
 326                                 continue;
 327
 328                         if (ifa->sa_family == AF_INET6 &&
 329                             (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) ||
 330                              IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr)))
 331                                 continue;
 332
 333                         if (ifindex && ifam->ifam_index != ifindex)
 334                                 continue;
 335
 336                         /* found */
 337                         *lenp = ifam->ifam_msglen;
 338                         return (char *)rtm;
 339                         /* NOTREACHED */
 340                 case RTM_IFINFO:
 341                         /* found */
 342                         *lenp = rtm->rtm_msglen;
 343                         return (char *)rtm;
 344                         /* NOTREACHED */
 345                 }
 346         }
 347
 348         return (char *)rtm;
 349 }
 350 #undef FILTER_MATCH
 351
 352 struct in6_addr *
 353 get_addr(char *buf)
 354 {
 355         struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
 356         struct sockaddr *sa, *rti_info[RTAX_MAX];
 357
 358         sa = (struct sockaddr *)(rtm + 1);
 359         get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
 360
 361         return(&SIN6(rti_info[RTAX_DST])->sin6_addr);
 362 }
 363
 364 int
 365 get_rtm_ifindex(char *buf)
 366 {
 367         struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
 368         struct sockaddr *sa, *rti_info[RTAX_MAX];
 369
 370         sa = (struct sockaddr *)(rtm + 1);
 371         get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
 372
 373         return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index);
 374 }
 375
 376 int
 377 get_ifm_ifindex(char *buf)
 378 {
 379         struct if_msghdr *ifm = (struct if_msghdr *)buf;
 380
 381         return ((int)ifm->ifm_index);
 382 }
 383
 384 int
 385 get_ifam_ifindex(char *buf)
 386 {
 387         struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf;
 388
 389         return ((int)ifam->ifam_index);
 390 }
 391
 392 int
 393 get_ifm_flags(char *buf)
 394 {
 395         struct if_msghdr *ifm = (struct if_msghdr *)buf;
 396
 397         return (ifm->ifm_flags);
 398 }
 399
 400 int
 401 get_prefixlen(char *buf)
 402 {
 403         struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
 404         struct sockaddr *sa, *rti_info[RTAX_MAX];
 405         u_char *p, *lim;
 406
 407         sa = (struct sockaddr *)(rtm + 1);
 408         get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
 409         sa = rti_info[RTAX_NETMASK];
 410
 411         p = (u_char *)(&SIN6(sa)->sin6_addr);
 412         lim = (u_char *)sa + sa->sa_len;
 413         return prefixlen(p, lim);
 414 }
 415
 416 int
 417 prefixlen(u_char *p, u_char *lim)
 418 {
 419         int masklen;
 420
 421         for (masklen = 0; p < lim; p++) {
 422                 switch (*p) {
 423                 case 0xff:
 424                         masklen += 8;
 425                         break;
 426                 case 0xfe:
 427                         masklen += 7;
 428                         break;
 429                 case 0xfc:
 430                         masklen += 6;
 431                         break;
 432                 case 0xf8:
 433                         masklen += 5;
 434                         break;
 435                 case 0xf0:
 436                         masklen += 4;
 437                         break;
 438                 case 0xe0:
 439                         masklen += 3;
 440                         break;
 441                 case 0xc0:
 442                         masklen += 2;
 443                         break;
 444                 case 0x80:
 445                         masklen += 1;
 446                         break;
 447                 case 0x00:
 448                         break;
 449                 default:
 450                         return(-1);
 451                 }
 452         }
 453
 454         return(masklen);
 455 }
 456
 457 int
 458 rtmsg_type(char *buf)
 459 {
 460         struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
 461
 462         return(rtm->rtm_type);
 463 }
 464
 465 int
 466 rtmsg_len(char *buf)
 467 {
 468         struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
 469
 470         return(rtm->rtm_msglen);
 471 }
 472
 473 int
 474 ifmsg_len(char *buf)
 475 {
 476         struct if_msghdr *ifm = (struct if_msghdr *)buf;
 477
 478         return(ifm->ifm_msglen);
 479 }
 480
 481 /*
 482  * alloc buffer and get if_msghdrs block from kernel,
 483  * and put them into the buffer
 484  */
 485 static void
 486 get_iflist(char **buf, size_t *size)
 487 {
 488         int mib[6];
 489
 490         mib[0] = CTL_NET;
 491         mib[1] = PF_ROUTE;
 492         mib[2] = 0;
 493         mib[3] = AF_INET6;
 494         mib[4] = NET_RT_IFLIST;
 495         mib[5] = 0;
 496
 497         if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) {
 498                 syslog(LOG_ERR, "<%s> sysctl: iflist size get failed",
 499                        __FUNCTION__);
 500                 exit(1);
 501         }
 502         if ((*buf = malloc(*size)) == NULL) {
 503                 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__);
 504                 exit(1);
 505         }
 506         if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) {
 507                 syslog(LOG_ERR, "<%s> sysctl: iflist get failed",
 508                        __FUNCTION__);
 509                 exit(1);
 510         }
 511         return;
 512 }
 513
 514 /*
 515  * alloc buffer and parse if_msghdrs block passed as arg,
 516  * and init the buffer as list of pointers ot each of the if_msghdr.
 517  */
 518 static void
 519 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize)
 520 {
 521         int iflentry_size, malloc_size;
 522         struct if_msghdr *ifm;
 523         struct ifa_msghdr *ifam;
 524         char *lim;
 525
 526         /*
 527          * Estimate least size of an iflist entry, to be obtained from kernel.
 528          * Should add sizeof(sockaddr) ??
 529          */
 530         iflentry_size = sizeof(struct if_msghdr);
 531         /* roughly estimate max list size of pointers to each if_msghdr */
 532         malloc_size = (bufsize/iflentry_size) * sizeof(size_t);
 533         if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) {
 534                 syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__);
 535                 exit(1);
 536         }
 537
 538         lim = buf + bufsize;
 539         for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) {
 540                 if (ifm->ifm_msglen == 0) {
 541                         syslog(LOG_WARNING, "<%s> ifm_msglen is 0 "
 542                                "(buf=%p lim=%p ifm=%p)", __FUNCTION__,
 543                                buf, lim, ifm);
 544                         return;
 545                 }
 546
 547                 if (ifm->ifm_type == RTM_IFINFO) {
 548                         (*ifmlist_p)[ifm->ifm_index] = ifm;
 549                 } else {
 550                         syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n"
 551                                "expected %d, got %d\n msglen = %d\n"
 552                                "buf:%p, ifm:%p, lim:%p\n",
 553                                RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen,
 554                                buf, ifm, lim);
 555                         exit (1);
 556                 }
 557                 for (ifam = (struct ifa_msghdr *)
 558                         ((char *)ifm + ifm->ifm_msglen);
 559                      ifam < (struct ifa_msghdr *)lim;
 560                      ifam = (struct ifa_msghdr *)
 561                         ((char *)ifam + ifam->ifam_msglen)) {
 562                         /* just for safety */
 563                         if (!ifam->ifam_msglen) {
 564                                 syslog(LOG_WARNING, "<%s> ifa_msglen is 0 "
 565                                        "(buf=%p lim=%p ifam=%p)", __FUNCTION__,
 566                                        buf, lim, ifam);
 567                                 return;
 568                         }
 569                         if (ifam->ifam_type != RTM_NEWADDR)
 570                                 break;
 571                 }
 572                 ifm = (struct if_msghdr *)ifam;
 573         }
 574 }
 575
 576 void
 577 init_iflist()
 578 {
 579         if (ifblock) {
 580                 free(ifblock);
 581                 ifblock_size = 0;
 582         }
 583         if (iflist)
 584                 free(iflist);
 585         /* get iflist block from kernel */
 586         get_iflist(&ifblock, &ifblock_size);
 587
 588         /* make list of pointers to each if_msghdr */
 589         parse_iflist(&iflist, ifblock, ifblock_size);
 590 }