arp.tproj/arp.c

   1 /*
   2  * Copyright (c) 2003-2012 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30  * Copyright (c) 1984, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * This code is derived from software contributed to Berkeley by
  34  * Sun Microsystems, Inc.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  */
  60
  61 #if 0
  62 #ifndef lint
  63 static char const copyright[] =
  64 "@(#) Copyright (c) 1984, 1993\n\
  65         The Regents of the University of California.  All rights reserved.\n";
  66 #endif /* not lint */
  67 #endif
  68
  69 /*
  70  * arp - display, set, and delete arp table entries
  71  */
  72
  73
  74 #include <sys/param.h>
  75 #include <sys/file.h>
  76 #include <sys/socket.h>
  77 #include <sys/sockio.h>
  78 #include <sys/sysctl.h>
  79 #include <sys/ioctl.h>
  80 #include <sys/time.h>
  81
  82 #include <net/if.h>
  83 #include <net/if_dl.h>
  84 #include <net/if_types.h>
  85 #include <net/route.h>
  86 #if 0
  87 #include <net/iso88025.h>
  88 #endif
  89
  90 #include <netinet/in.h>
  91 #include <netinet/if_ether.h>
  92
  93 #include <arpa/inet.h>
  94
  95 #include <ctype.h>
  96 #include <err.h>
  97 #include <errno.h>
  98 #include <netdb.h>
  99 #include <nlist.h>
 100 #include <paths.h>
 101 #include <stdio.h>
 102 #include <stdlib.h>
 103 #include <string.h>
 104 #include <strings.h>
 105 #include <unistd.h>
 106
 107 typedef void (action_fn)(struct sockaddr_dl *sdl,
 108         struct sockaddr_inarp *s_in, struct rt_msghdr *rtm);
 109 typedef void (action_ext_fn)(struct sockaddr_dl *sdl,
 110         struct sockaddr_inarp *s_in, struct rt_msghdr_ext *rtm);
 111
 112 static int search(in_addr_t addr, action_fn *action);
 113 static int search_ext(in_addr_t addr, action_ext_fn *action);
 114 static action_fn print_entry;
 115 static action_fn nuke_entry;
 116 static action_ext_fn print_entry_ext;
 117
 118 static char *print_lladdr(struct sockaddr_dl *);
 119 static int delete(char *host, int do_proxy);
 120 static void usage(void);
 121 static int set(int argc, char **argv);
 122 static int get(char *host);
 123 static int file(char *name);
 124 static struct rt_msghdr *rtmsg(int cmd,
 125     struct sockaddr_inarp *dst, struct sockaddr_dl *sdl);
 126 static int get_ether_addr(in_addr_t ipaddr, struct ether_addr *hwaddr);
 127 static struct sockaddr_inarp *getaddr(char *host);
 128 static int valid_type(int type);
 129 static char *sec2str(time_t);
 130
 131 static int nflag;       /* no reverse dns lookups */
 132 static int xflag;       /* extended link-layer reachability information */
 133 static char *rifname;
 134
 135 static int      expire_time, flags, doing_proxy, proxy_only;
 136
 137 static char *boundif = NULL;
 138 static unsigned int ifscope = 0;
 139
 140 /* which function we're supposed to do */
 141 #define F_GET           1
 142 #define F_SET           2
 143 #define F_FILESET       3
 144 #define F_REPLACE       4
 145 #define F_DELETE        5
 146
 147 #ifndef SA_SIZE
 148 #define SA_SIZE(sa)                                             \
 149     (  (!(sa) || ((struct sockaddr *)(sa))->sa_len == 0) ?      \
 150         sizeof(uint32_t)            :                               \
 151         1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(uint32_t) - 1) ) )
 152 #endif
 153
 154 #define SETFUNC(f)      { if (func) usage(); func = (f); }
 155
 156
 157 int
 158 main(int argc, char *argv[])
 159 {
 160         int ch, func = 0;
 161         int rtn = 0;
 162         int aflag = 0;  /* do it for all entries */
 163         int lflag = 0;
 164         uint32_t ifindex = 0;
 165
 166         while ((ch = getopt(argc, argv, "andflsSi:x")) != -1)
 167                 switch((char)ch) {
 168                 case 'a':
 169                         aflag = 1;
 170                         break;
 171                 case 'd':
 172                         SETFUNC(F_DELETE);
 173                         break;
 174                 case 'n':
 175                         nflag = 1;
 176                         break;
 177                 case 'l':
 178                         lflag = 1;
 179                         break;
 180                 case 'S':
 181                         SETFUNC(F_REPLACE);
 182                         break;
 183                 case 's':
 184                         SETFUNC(F_SET);
 185                         break;
 186                 case 'f' :
 187                         SETFUNC(F_FILESET);
 188                         break;
 189                 case 'i':
 190                         rifname = optarg;
 191                         break;
 192                 case 'x':
 193                         xflag = 1;
 194                         lflag = 1;
 195                         break;
 196                 case '?':
 197                 default:
 198                         usage();
 199                 }
 200         argc -= optind;
 201         argv += optind;
 202
 203         if (!func)
 204                 func = F_GET;
 205         if (rifname) {
 206                 if (func != F_GET && !(func == F_DELETE && aflag))
 207                         errx(1, "-i not applicable to this operation");
 208                 if ((ifindex = if_nametoindex(rifname)) == 0) {
 209                         if (errno == ENXIO)
 210                                 errx(1, "interface %s does not exist", rifname);
 211                         else
 212                                 err(1, "if_nametoindex(%s)", rifname);
 213                 }
 214         }
 215         switch (func) {
 216         case F_GET:
 217                 if (aflag) {
 218                         if (argc != 0)
 219                                 usage();
 220                         if (lflag) {
 221                                 printf("%-23s %-17s %-9.9s %-9.9s %8.8s %4s "
 222                                     "%4s", "Neighbor",
 223                                     "Linklayer Address", "Expire(O)",
 224                                     "Expire(I)", "Netif", "Refs", "Prbs");
 225                                 if (xflag)
 226                                         printf(" %-7.7s %-7.7s %-7.7s",
 227                                             "RSSI", "LQM", "NPM");
 228                                 printf("\n");
 229                                 search_ext(0, print_entry_ext);
 230                         } else {
 231                                 search(0, print_entry);
 232                         }
 233                 } else {
 234                         if (argc != 1)
 235                                 usage();
 236                         rtn = get(argv[0]);
 237                 }
 238                 break;
 239         case F_SET:
 240         case F_REPLACE:
 241                 if (argc < 2 || argc > 6)
 242                         usage();
 243                 if (func == F_REPLACE)
 244                         (void)delete(argv[0], 0);
 245                 rtn = set(argc, argv) ? 1 : 0;
 246                 break;
 247         case F_DELETE:
 248                 if (aflag) {
 249                         if (argc != 0)
 250                                 usage();
 251                         search(0, nuke_entry);
 252                 } else {
 253                         int do_proxy = 0;
 254                         int i;
 255
 256                         for (i = 1; i < argc; i++) {
 257                                 if (strncmp(argv[i], "pub", sizeof("pub")) == 0) {
 258                                         do_proxy = SIN_PROXY;
 259                                 } else if (strncmp(argv[i], "ifscope", sizeof("ifscope")) == 0) {
 260                                         if (i + 1 >= argc) {
 261                                                 printf("ifscope needs an interface parameter\n");
 262                                                 return (1);
 263                                         }
 264                                         boundif = argv[++i];
 265                                         if ((ifscope = if_nametoindex(boundif)) == 0)
 266                                                 errx(1, "ifscope has bad interface name: %s", boundif);
 267                                 } else {
 268                                         usage();
 269                                 }
 270                         }
 271                         if (i > argc)
 272                                 usage();
 273                         rtn = delete(argv[0], do_proxy);
 274                 }
 275                 break;
 276         case F_FILESET:
 277                 if (argc != 1)
 278                         usage();
 279                 rtn = file(argv[0]);
 280                 break;
 281         }
 282
 283         return (rtn);
 284 }
 285
 286 /*
 287  * Process a file to set standard arp entries
 288  */
 289 static int
 290 file(char *name)
 291 {
 292         FILE *fp;
 293         int i, retval;
 294         char line[128], arg[7][50], *args[7], *p;
 295
 296         if ((fp = fopen(name, "r")) == NULL)
 297                 err(1, "cannot open %s", name);
 298         args[0] = &arg[0][0];
 299         args[1] = &arg[1][0];
 300         args[2] = &arg[2][0];
 301         args[3] = &arg[3][0];
 302         args[4] = &arg[4][0];
 303         args[5] = &arg[5][0];
 304         args[6] = &arg[6][0];
 305         retval = 0;
 306         while(fgets(line, sizeof(line), fp) != NULL) {
 307                 if ((p = strchr(line, '#')) != NULL)
 308                         *p = '\0';
 309                 for (p = line; isblank(*p); p++);
 310                 if (*p == '\n' || *p == '\0')
 311                         continue;
 312                 i = sscanf(p, "%49s %49s %49s %49s %49s %49s %49s", arg[0], arg[1],
 313                     arg[2], arg[3], arg[4], arg[5], arg[6]);
 314                 if (i < 2) {
 315                         warnx("bad line: %s", line);
 316                         retval = 1;
 317                         continue;
 318                 }
 319                 if (set(i, args))
 320                         retval = 1;
 321         }
 322         fclose(fp);
 323         return (retval);
 324 }
 325
 326 /*
 327  * Given a hostname, fills up a (static) struct sockaddr_inarp with
 328  * the address of the host and returns a pointer to the
 329  * structure.
 330  */
 331 static struct sockaddr_inarp *
 332 getaddr(char *host)
 333 {
 334         struct hostent *hp;
 335         static struct sockaddr_inarp reply;
 336
 337         bzero(&reply, sizeof(reply));
 338         reply.sin_len = sizeof(reply);
 339         reply.sin_family = AF_INET;
 340         reply.sin_addr.s_addr = inet_addr(host);
 341         if (reply.sin_addr.s_addr == INADDR_NONE) {
 342                 if (!(hp = gethostbyname(host))) {
 343                         warnx("%s: %s", host, hstrerror(h_errno));
 344                         return (NULL);
 345                 }
 346                 bcopy((char *)hp->h_addr, (char *)&reply.sin_addr,
 347                         sizeof reply.sin_addr);
 348         }
 349         return (&reply);
 350 }
 351
 352 /*
 353  * Returns true if the type is a valid one for ARP.
 354  */
 355 static int
 356 valid_type(int type)
 357 {
 358
 359         switch (type) {
 360         case IFT_ETHER:
 361         case IFT_FDDI:
 362         case IFT_ISO88023:
 363         case IFT_ISO88024:
 364 #if 0
 365         case IFT_ISO88025:
 366 #endif
 367         case IFT_L2VLAN:
 368 #ifdef IFT_BRIDGE
 369         case IFT_BRIDGE:
 370 #endif
 371                 return (1);
 372         default:
 373                 return (0);
 374         }
 375 }
 376
 377 /*
 378  * Set an individual arp entry
 379  */
 380 static int
 381 set(int argc, char **argv)
 382 {
 383         struct sockaddr_inarp *addr;
 384         struct sockaddr_inarp *dst;     /* what are we looking for */
 385         struct sockaddr_dl *sdl;
 386         struct rt_msghdr *rtm;
 387         struct ether_addr *ea;
 388         char *host = argv[0], *eaddr = argv[1];
 389         struct sockaddr_dl sdl_m;
 390
 391         argc -= 2;
 392         argv += 2;
 393
 394         bzero(&sdl_m, sizeof(sdl_m));
 395         sdl_m.sdl_len = sizeof(sdl_m);
 396         sdl_m.sdl_family = AF_LINK;
 397
 398         dst = getaddr(host);
 399         if (dst == NULL)
 400                 return (1);
 401         doing_proxy = flags = proxy_only = expire_time = 0;
 402         boundif = NULL;
 403         ifscope = 0;
 404         while (argc-- > 0) {
 405                 if (strncmp(argv[0], "temp", sizeof("temp")) == 0) {
 406                         struct timeval tv;
 407                         gettimeofday(&tv, 0);
 408                         expire_time = tv.tv_sec + 20 * 60;
 409                 } else if (strncmp(argv[0], "pub", sizeof("pub")) == 0) {
 410                         flags |= RTF_ANNOUNCE;
 411                         doing_proxy = 1;
 412                         if (argc && strncmp(argv[1], "only", sizeof("only")) == 0) {
 413                                 proxy_only = 1;
 414                                 dst->sin_other = SIN_PROXY;
 415                                 argc--; argv++;
 416                         }
 417                 } else if (strncmp(argv[0], "blackhole", sizeof("blackhole")) == 0) {
 418                         flags |= RTF_BLACKHOLE;
 419                 } else if (strncmp(argv[0], "reject", sizeof("reject")) == 0) {
 420                         flags |= RTF_REJECT;
 421                 } else if (strncmp(argv[0], "trail", sizeof("trail")) == 0) {
 422                         /* XXX deprecated and undocumented feature */
 423                         printf("%s: Sending trailers is no longer supported\n",
 424                                 host);
 425                 } else if (strncmp(argv[0], "ifscope", sizeof("ifscope")) == 0) {
 426                         if (argc < 1) {
 427                                 printf("ifscope needs an interface parameter\n");
 428                                 return (1);
 429                         }
 430                         boundif = argv[1];
 431                         if ((ifscope = if_nametoindex(boundif)) == 0)
 432                                 errx(1, "ifscope has bad interface name: %s", boundif);
 433                         argc--; argv++;
 434                 }
 435                 argv++;
 436         }
 437         ea = (struct ether_addr *)LLADDR(&sdl_m);
 438         if (doing_proxy && !strcmp(eaddr, "auto")) {
 439                 if (!get_ether_addr(dst->sin_addr.s_addr, ea)) {
 440                         printf("no interface found for %s\n",
 441                                inet_ntoa(dst->sin_addr));
 442                         return (1);
 443                 }
 444                 sdl_m.sdl_alen = ETHER_ADDR_LEN;
 445         } else {
 446                 struct ether_addr *ea1 = ether_aton(eaddr);
 447
 448                 if (ea1 == NULL) {
 449                         warnx("invalid Ethernet address '%s'", eaddr);
 450                         return (1);
 451                 } else {
 452                         *ea = *ea1;
 453                         sdl_m.sdl_alen = ETHER_ADDR_LEN;
 454                 }
 455         }
 456         for (;;) {      /* try at most twice */
 457                 rtm = rtmsg(RTM_GET, dst, &sdl_m);
 458                 if (rtm == NULL) {
 459                         warn("%s", host);
 460                         return (1);
 461                 }
 462                 addr = (struct sockaddr_inarp *)(rtm + 1);
 463                 sdl = (struct sockaddr_dl *)(SA_SIZE(addr) + (char *)addr);
 464                 if (addr->sin_addr.s_addr != dst->sin_addr.s_addr)
 465                         break;
 466                 if (sdl->sdl_family == AF_LINK &&
 467                     (rtm->rtm_flags & RTF_LLINFO) &&
 468                     !(rtm->rtm_flags & RTF_GATEWAY) &&
 469                     valid_type(sdl->sdl_type) )
 470                         break;
 471                 /*
 472                  * If we asked for a scope entry and did not get one or
 473                  * did not asked for a scope entry and got one, we can
 474                  * proceed.
 475                  */
 476                 if ((ifscope != 0) != (rtm->rtm_flags & RTF_IFSCOPE))
 477                         break;
 478                 if (doing_proxy == 0) {
 479                         printf("set: can only proxy for %s\n", host);
 480                         return (1);
 481                 }
 482                 if (dst->sin_other & SIN_PROXY) {
 483                         printf("set: proxy entry exists for non 802 device\n");
 484                         return (1);
 485                 }
 486                 dst->sin_other = SIN_PROXY;
 487                 proxy_only = 1;
 488         }
 489
 490         if (sdl->sdl_family != AF_LINK) {
 491                 printf("cannot intuit interface index and type for %s\n", host);
 492                 return (1);
 493         }
 494         sdl_m.sdl_type = sdl->sdl_type;
 495         sdl_m.sdl_index = sdl->sdl_index;
 496         return (rtmsg(RTM_ADD, dst, &sdl_m) == NULL);
 497 }
 498
 499 /*
 500  * Display an individual arp entry
 501  */
 502 static int
 503 get(char *host)
 504 {
 505         struct sockaddr_inarp *addr;
 506
 507         addr = getaddr(host);
 508         if (addr == NULL)
 509                 return (1);
 510         if (0 == search(addr->sin_addr.s_addr, print_entry)) {
 511                 printf("%s (%s) -- no entry",
 512                     host, inet_ntoa(addr->sin_addr));
 513                 if (rifname)
 514                         printf(" on %s", rifname);
 515                 printf("\n");
 516                 return (1);
 517         }
 518         return (0);
 519 }
 520
 521 /*
 522  * Delete an arp entry
 523  */
 524 static int
 525 delete(char *host, int do_proxy)
 526 {
 527         struct sockaddr_inarp *addr, *dst;
 528         struct rt_msghdr *rtm;
 529         struct sockaddr_dl *sdl;
 530
 531         dst = getaddr(host);
 532         if (dst == NULL)
 533                 return (1);
 534         dst->sin_other = do_proxy;
 535         for (;;) {      /* try twice */
 536                 rtm = rtmsg(RTM_GET, dst, NULL);
 537                 if (rtm == NULL) {
 538                         warn("%s", host);
 539                         return (1);
 540                 }
 541                 addr = (struct sockaddr_inarp *)(rtm + 1);
 542                 sdl = (struct sockaddr_dl *)(SA_SIZE(addr) + (char *)addr);
 543                 if (addr->sin_addr.s_addr == dst->sin_addr.s_addr &&
 544                     sdl->sdl_family == AF_LINK &&
 545                     (rtm->rtm_flags & RTF_LLINFO) &&
 546                     !(rtm->rtm_flags & RTF_GATEWAY) &&
 547                     valid_type(sdl->sdl_type) )
 548                         break;  /* found it */
 549                 if (dst->sin_other & SIN_PROXY) {
 550                         fprintf(stderr, "delete: cannot locate %s\n",host);
 551                         return (1);
 552                 }
 553                 dst->sin_other = SIN_PROXY;
 554         }
 555         if (rtmsg(RTM_DELETE, dst, NULL) != NULL) {
 556                 printf("%s (%s) deleted\n", host, inet_ntoa(addr->sin_addr));
 557                 return (0);
 558         }
 559         return (1);
 560 }
 561
 562 /*
 563  * Search the arp table and do some action on matching entries
 564  */
 565 static int
 566 search(in_addr_t addr, action_fn *action)
 567 {
 568         int mib[6];
 569         size_t needed;
 570         char *lim, *buf, *newbuf, *next;
 571         struct rt_msghdr *rtm;
 572         struct sockaddr_inarp *sin2;
 573         struct sockaddr_dl *sdl;
 574         char ifname[IF_NAMESIZE];
 575         int st, found_entry = 0;
 576
 577         mib[0] = CTL_NET;
 578         mib[1] = PF_ROUTE;
 579         mib[2] = 0;
 580         mib[3] = AF_INET;
 581         mib[4] = NET_RT_FLAGS;
 582         mib[5] = RTF_LLINFO;
 583         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 584                 err(1, "route-sysctl-estimate");
 585         if (needed == 0)        /* empty table */
 586                 return 0;
 587         buf = NULL;
 588         for (;;) {
 589                 newbuf = realloc(buf, needed);
 590                 if (newbuf == NULL) {
 591                         if (buf != NULL)
 592                                 free(buf);
 593                         errx(1, "could not reallocate memory");
 594                 }
 595                 buf = newbuf;
 596                 st = sysctl(mib, 6, buf, &needed, NULL, 0);
 597                 if (st == 0 || errno != ENOMEM)
 598                         break;
 599                 needed += needed / 8;
 600         }
 601         if (st == -1)
 602                 err(1, "actual retrieval of routing table");
 603         lim = buf + needed;
 604         for (next = buf; next < lim; next += rtm->rtm_msglen) {
 605                 rtm = (struct rt_msghdr *)next;
 606                 sin2 = (struct sockaddr_inarp *)(rtm + 1);
 607                 sdl = (struct sockaddr_dl *)((char *)sin2 + SA_SIZE(sin2));
 608                 if (rifname && if_indextoname(sdl->sdl_index, ifname) &&
 609                     strcmp(ifname, rifname))
 610                         continue;
 611                 if (addr) {
 612                         if (addr != sin2->sin_addr.s_addr)
 613                                 continue;
 614                         found_entry = 1;
 615                 }
 616                 (*action)(sdl, sin2, rtm);
 617         }
 618         free(buf);
 619         return (found_entry);
 620 }
 621
 622 /*
 623  * Stolen and adapted from ifconfig
 624  */
 625 static char *
 626 print_lladdr(struct sockaddr_dl *sdl)
 627 {
 628         static char buf[256];
 629         char *cp;
 630         int n, bufsize = sizeof (buf), p = 0;
 631
 632         bzero(buf, sizeof (buf));
 633         cp = (char *)LLADDR(sdl);
 634         if ((n = sdl->sdl_alen) > 0) {
 635                 while (--n >= 0)
 636                         p += snprintf(buf + p, bufsize - p, "%x%s",
 637                             *cp++ & 0xff, n > 0 ? ":" : "");
 638         }
 639         return (buf);
 640 }
 641
 642 /*
 643  * Display an arp entry
 644  */
 645 static void
 646 print_entry(struct sockaddr_dl *sdl,
 647         struct sockaddr_inarp *addr, struct rt_msghdr *rtm)
 648 {
 649         const char *host;
 650         struct hostent *hp;
 651         char ifname[IF_NAMESIZE];
 652 #if 0
 653         struct iso88025_sockaddr_dl_data *trld;
 654         int seg;
 655 #endif
 656
 657         if (nflag == 0)
 658                 hp = gethostbyaddr((caddr_t)&(addr->sin_addr),
 659                     sizeof addr->sin_addr, AF_INET);
 660         else
 661                 hp = 0;
 662         if (hp)
 663                 host = hp->h_name;
 664         else {
 665                 host = "?";
 666                 if (h_errno == TRY_AGAIN)
 667                         nflag = 1;
 668         }
 669         printf("%s (%s) at ", host, inet_ntoa(addr->sin_addr));
 670         if (sdl->sdl_alen) {
 671 #if 1
 672                 printf("%s", print_lladdr(sdl));
 673 #else
 674                 if ((sdl->sdl_type == IFT_ETHER ||
 675                     sdl->sdl_type == IFT_L2VLAN ||
 676                     sdl->sdl_type == IFT_BRIDGE) &&
 677                     sdl->sdl_alen == ETHER_ADDR_LEN)
 678                         printf("%s", ether_ntoa((struct ether_addr *)LLADDR(sdl)));
 679                 else {
 680                         int n = sdl->sdl_nlen > 0 ? sdl->sdl_nlen + 1 : 0;
 681
 682                         printf("%s", link_ntoa(sdl) + n);
 683                 }
 684 #endif
 685         } else
 686                 printf("(incomplete)");
 687         if (if_indextoname(sdl->sdl_index, ifname) != NULL)
 688                 printf(" on %s", ifname);
 689         if ((rtm->rtm_flags & RTF_IFSCOPE))
 690                 printf(" ifscope");
 691         if (rtm->rtm_rmx.rmx_expire == 0)
 692                 printf(" permanent");
 693         if (addr->sin_other & SIN_PROXY)
 694                 printf(" published (proxy only)");
 695         if (rtm->rtm_addrs & RTA_NETMASK) {
 696                 addr = (struct sockaddr_inarp *)
 697                         (SA_SIZE(sdl) + (char *)sdl);
 698                 if (addr->sin_addr.s_addr == 0xffffffff)
 699                         printf(" published");
 700                 if (addr->sin_len != 8)
 701                         printf("(weird)");
 702         }
 703         switch(sdl->sdl_type) {
 704         case IFT_ETHER:
 705                 printf(" [ethernet]");
 706                 break;
 707 #if 0
 708         case IFT_ISO88025:
 709                 printf(" [token-ring]");
 710                 trld = SDL_ISO88025(sdl);
 711                 if (trld->trld_rcf != 0) {
 712                         printf(" rt=%x", ntohs(trld->trld_rcf));
 713                         for (seg = 0;
 714                              seg < ((TR_RCF_RIFLEN(trld->trld_rcf) - 2 ) / 2);
 715                              seg++)
 716                                 printf(":%x", ntohs(*(trld->trld_route[seg])));
 717                 }
 718                 break;
 719 #endif
 720         case IFT_FDDI:
 721                 printf(" [fddi]");
 722                 break;
 723         case IFT_ATM:
 724                 printf(" [atm]");
 725                 break;
 726         case IFT_L2VLAN:
 727                 printf(" [vlan]");
 728                 break;
 729         case IFT_IEEE1394:
 730                 printf(" [firewire]");
 731                 break;
 732 #ifdef IFT_BRIDGE
 733         case IFT_BRIDGE:
 734                 printf(" [bridge]");
 735                 break;
 736 #endif
 737         default:
 738                 break;
 739         }
 740
 741         printf("\n");
 742
 743 }
 744
 745 /*
 746  * Nuke an arp entry
 747  */
 748 static void
 749 nuke_entry(struct sockaddr_dl *sdl __unused,
 750         struct sockaddr_inarp *addr, struct rt_msghdr *rtm)
 751 {
 752         char ip[20];
 753
 754         snprintf(ip, sizeof(ip), "%s", inet_ntoa(addr->sin_addr));
 755         /*
 756          * When deleting all entries, specify the interface scope of each entry
 757          */
 758         if ((rtm->rtm_flags & RTF_IFSCOPE))
 759                 ifscope = rtm->rtm_index;
 760         (void)delete(ip, 0);
 761         ifscope = 0;
 762 }
 763
 764 static void
 765 usage(void)
 766 {
 767         fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n%s\n",
 768                 "usage: arp [-n] [-i interface] hostname",
 769                 "       arp [-n] [-i interface] [-l] -a",
 770                 "       arp -d hostname [pub] [ifscope interface]",
 771                 "       arp -d [-i interface] -a",
 772                 "       arp -s hostname ether_addr [temp] [reject] [blackhole] [pub [only]] [ifscope interface]",
 773                 "       arp -S hostname ether_addr [temp] [reject] [blackhole] [pub [only]] [ifscope interface]",
 774                 "       arp -f filename");
 775         exit(1);
 776 }
 777
 778 static struct rt_msghdr *
 779 rtmsg(int cmd, struct sockaddr_inarp *dst, struct sockaddr_dl *sdl)
 780 {
 781         static int seq;
 782         int rlen;
 783         int l;
 784         struct sockaddr_in so_mask, *so_mask_ptr = &so_mask;
 785         static int s = -1;
 786         static pid_t pid;
 787
 788         static struct   {
 789                 struct  rt_msghdr m_rtm;
 790                 char    m_space[512];
 791         }       m_rtmsg;
 792
 793         struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
 794         char *cp = m_rtmsg.m_space;
 795
 796         if (s < 0) {    /* first time: open socket, get pid */
 797                 s = socket(PF_ROUTE, SOCK_RAW, 0);
 798                 if (s < 0)
 799                         err(1, "socket");
 800                 pid = getpid();
 801         }
 802         bzero(&so_mask, sizeof(so_mask));
 803         so_mask.sin_len = 8;
 804         so_mask.sin_addr.s_addr = 0xffffffff;
 805
 806         errno = 0;
 807         /*
 808          * XXX RTM_DELETE relies on a previous RTM_GET to fill the buffer
 809          * appropriately (except for the mask set just above).
 810          */
 811         if (cmd == RTM_DELETE)
 812                 goto doit;
 813         bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
 814         rtm->rtm_flags = flags;
 815         rtm->rtm_version = RTM_VERSION;
 816
 817         /*
 818          * Note: On RTM_GET the kernel will return a scoped route when both a scoped route and
 819          * a unscoped route exist. That means we cannot delete a unscoped route if there is
 820          * also a matching scope route
 821          */
 822         if (ifscope) {
 823                 rtm->rtm_index = ifscope;
 824                 rtm->rtm_flags |= RTF_IFSCOPE;
 825         }
 826
 827         switch (cmd) {
 828         default:
 829                 errx(1, "internal wrong cmd");
 830         case RTM_ADD:
 831                 rtm->rtm_addrs |= RTA_GATEWAY;
 832                 rtm->rtm_rmx.rmx_expire = expire_time;
 833                 rtm->rtm_inits = RTV_EXPIRE;
 834                 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
 835                 dst->sin_other = 0;
 836                 if (doing_proxy) {
 837                         if (proxy_only)
 838                                 dst->sin_other = SIN_PROXY;
 839                         else {
 840                                 rtm->rtm_addrs |= RTA_NETMASK;
 841                                 rtm->rtm_flags &= ~RTF_HOST;
 842                         }
 843                 }
 844                 /* FALLTHROUGH */
 845         case RTM_GET:
 846                 rtm->rtm_addrs |= RTA_DST;
 847         }
 848 #define NEXTADDR(w, s) \
 849         if ((s) != NULL && rtm->rtm_addrs & (w)) { \
 850                 bcopy((s), cp, sizeof(*(s))); cp += SA_SIZE(s);}
 851
 852         NEXTADDR(RTA_DST, dst);
 853         NEXTADDR(RTA_GATEWAY, sdl);
 854         NEXTADDR(RTA_NETMASK, so_mask_ptr);
 855
 856         rtm->rtm_msglen = cp - (char *)&m_rtmsg;
 857 doit:
 858         l = rtm->rtm_msglen;
 859         rtm->rtm_seq = ++seq;
 860         rtm->rtm_type = cmd;
 861         if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
 862                 if (errno != ESRCH || cmd != RTM_DELETE) {
 863                         warn("writing to routing socket");
 864                         return (NULL);
 865                 }
 866         }
 867         do {
 868                 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
 869         } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
 870         if (l < 0)
 871                 warn("read from routing socket");
 872         return (rtm);
 873 }
 874
 875 /*
 876  * get_ether_addr - get the hardware address of an interface on the
 877  * the same subnet as ipaddr.
 878  */
 879 #define MAX_IFS         32
 880
 881 static int
 882 get_ether_addr(in_addr_t ipaddr, struct ether_addr *hwaddr)
 883 {
 884         struct ifreq *ifr, *ifend, *ifp;
 885         in_addr_t ina, mask;
 886         struct sockaddr_dl *dla;
 887         struct ifreq ifreq;
 888         struct ifconf ifc;
 889         struct ifreq ifs[MAX_IFS];
 890         int sock;
 891         int retval = 0;
 892
 893         sock = socket(AF_INET, SOCK_DGRAM, 0);
 894         if (sock < 0)
 895                 err(1, "socket");
 896
 897         ifc.ifc_len = sizeof(ifs);
 898         ifc.ifc_req = ifs;
 899         if (ioctl(sock, SIOCGIFCONF, &ifc) < 0) {
 900                 warnx("ioctl(SIOCGIFCONF)");
 901                 goto done;
 902         }
 903
 904 #define NEXTIFR(i)                                              \
 905     ((struct ifreq *)((char *)&(i)->ifr_addr                    \
 906         + MAX((i)->ifr_addr.sa_len, sizeof((i)->ifr_addr))) )
 907
 908         /*
 909          * Scan through looking for an interface with an Internet
 910          * address on the same subnet as `ipaddr'.
 911          */
 912         ifend = (struct ifreq *)(ifc.ifc_buf + ifc.ifc_len);
 913         for (ifr = ifc.ifc_req; ifr < ifend; ifr = NEXTIFR(ifr) ) {
 914                 if (ifr->ifr_addr.sa_family != AF_INET)
 915                         continue;
 916                 strncpy(ifreq.ifr_name, ifr->ifr_name,
 917                         sizeof(ifreq.ifr_name));
 918                 ifreq.ifr_addr = ifr->ifr_addr;
 919                 /*
 920                  * Check that the interface is up,
 921                  * and not point-to-point or loopback.
 922                  */
 923                 if (ioctl(sock, SIOCGIFFLAGS, &ifreq) < 0)
 924                         continue;
 925                 if ((ifreq.ifr_flags &
 926                      (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|
 927                                 IFF_LOOPBACK|IFF_NOARP))
 928                      != (IFF_UP|IFF_BROADCAST))
 929                         continue;
 930                 /*
 931                  * Get its netmask and check that it's on
 932                  * the right subnet.
 933                  */
 934                 if (ioctl(sock, SIOCGIFNETMASK, &ifreq) < 0)
 935                         continue;
 936                 mask = ((struct sockaddr_in *)
 937                         &ifreq.ifr_addr)->sin_addr.s_addr;
 938                 ina = ((struct sockaddr_in *)
 939                         &ifr->ifr_addr)->sin_addr.s_addr;
 940                 if ((ipaddr & mask) == (ina & mask))
 941                         break; /* ok, we got it! */
 942         }
 943
 944         if (ifr >= ifend)
 945                 goto done;
 946
 947         /*
 948          * Now scan through again looking for a link-level address
 949          * for this interface.
 950          */
 951         ifp = ifr;
 952         for (ifr = ifc.ifc_req; ifr < ifend; ifr = NEXTIFR(ifr))
 953                 if (strcmp(ifp->ifr_name, ifr->ifr_name) == 0 &&
 954                     ifr->ifr_addr.sa_family == AF_LINK)
 955                         break;
 956         if (ifr >= ifend)
 957                 goto done;
 958         /*
 959          * Found the link-level address - copy it out
 960          */
 961         dla = (struct sockaddr_dl *) &ifr->ifr_addr;
 962         memcpy(hwaddr,  LLADDR(dla), dla->sdl_alen);
 963         printf("using interface %s for proxy with address ",
 964                 ifp->ifr_name);
 965         printf("%s\n", ether_ntoa(hwaddr));
 966         retval = dla->sdl_alen;
 967 done:
 968         close(sock);
 969         return (retval);
 970 }
 971
 972 static char *
 973 sec2str(total)
 974         time_t total;
 975 {
 976         static char result[256];
 977         int days, hours, mins, secs;
 978         int first = 1;
 979         char *p = result;
 980
 981         days = total / 3600 / 24;
 982         hours = (total / 3600) % 24;
 983         mins = (total / 60) % 60;
 984         secs = total % 60;
 985
 986         if (days) {
 987                 first = 0;
 988                 p += snprintf(p, sizeof(result) - (p - result), "%dd", days);
 989         }
 990         if (!first || hours) {
 991                 first = 0;
 992                 p += snprintf(p, sizeof(result) - (p - result), "%dh", hours);
 993         }
 994         if (!first || mins) {
 995                 first = 0;
 996                 p += snprintf(p, sizeof(result) - (p - result), "%dm", mins);
 997         }
 998         snprintf(p, sizeof(result) - (p - result), "%ds", secs);
 999
1000         return(result);
1001 }
1002
1003 static int
1004 search_ext(in_addr_t addr, action_ext_fn *action)
1005 {
1006         int mib[6];
1007         size_t needed;
1008         char *lim, *buf, *newbuf, *next;
1009         struct rt_msghdr_ext *ertm;
1010         struct sockaddr_inarp *sin2;
1011         struct sockaddr_dl *sdl;
1012         char ifname[IF_NAMESIZE];
1013         int st, found_entry = 0;
1014
1015         mib[0] = CTL_NET;
1016         mib[1] = PF_ROUTE;
1017         mib[2] = 0;
1018         mib[3] = AF_INET;
1019         mib[4] = NET_RT_DUMPX_FLAGS;
1020         mib[5] = RTF_LLINFO;
1021         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
1022                 err(1, "route-sysctl-estimate");
1023         if (needed == 0)        /* empty table */
1024                 return 0;
1025         buf = NULL;
1026         for (;;) {
1027                 newbuf = realloc(buf, needed);
1028                 if (newbuf == NULL) {
1029                         if (buf != NULL)
1030                                 free(buf);
1031                         errx(1, "could not reallocate memory");
1032                 }
1033                 buf = newbuf;
1034                 st = sysctl(mib, 6, buf, &needed, NULL, 0);
1035                 if (st == 0 || errno != ENOMEM)
1036                         break;
1037                 needed += needed / 8;
1038         }
1039         if (st == -1)
1040                 err(1, "actual retrieval of routing table");
1041         lim = buf + needed;
1042         for (next = buf; next < lim; next += ertm->rtm_msglen) {
1043                 ertm = (struct rt_msghdr_ext *)next;
1044                 sin2 = (struct sockaddr_inarp *)(ertm + 1);
1045                 sdl = (struct sockaddr_dl *)((char *)sin2 + SA_SIZE(sin2));
1046                 if (rifname && if_indextoname(sdl->sdl_index, ifname) &&
1047                     strcmp(ifname, rifname))
1048                         continue;
1049                 if (addr) {
1050                         if (addr != sin2->sin_addr.s_addr)
1051                                 continue;
1052                         found_entry = 1;
1053                 }
1054                 (*action)(sdl, sin2, ertm);
1055         }
1056         free(buf);
1057         return (found_entry);
1058 }
1059
1060 static void
1061 print_entry_ext(struct sockaddr_dl *sdl, struct sockaddr_inarp *addr,
1062     struct rt_msghdr_ext *ertm)
1063 {
1064         const char *host;
1065         struct hostent *hp;
1066         char ifname[IF_NAMESIZE];
1067         struct timeval time;
1068
1069         if (nflag == 0)
1070                 hp = gethostbyaddr((caddr_t)&(addr->sin_addr),
1071                     sizeof (addr->sin_addr), AF_INET);
1072         else
1073                 hp = 0;
1074
1075         if (hp)
1076                 host = hp->h_name;
1077         else
1078                 host = inet_ntoa(addr->sin_addr);
1079
1080         printf("%-23s ", host);
1081
1082         if (sdl->sdl_alen)
1083                 printf("%-17s ", print_lladdr(sdl));
1084         else
1085                 printf("%-17s ", "(incomplete)");
1086
1087         gettimeofday(&time, 0);
1088
1089         if (ertm->rtm_ri.ri_refcnt == 0 || ertm->rtm_ri.ri_snd_expire == 0)
1090                 printf("%-9.9s ", "(none)");
1091         else if (ertm->rtm_ri.ri_snd_expire > time.tv_sec)
1092                 printf("%-9.9s ",
1093                     sec2str(ertm->rtm_ri.ri_snd_expire - time.tv_sec));
1094         else
1095                 printf("%-9.9s ", "expired");
1096
1097         if (ertm->rtm_ri.ri_refcnt == 0 || ertm->rtm_ri.ri_rcv_expire == 0)
1098                 printf("%-9.9s", "(none)");
1099         else if (ertm->rtm_ri.ri_rcv_expire > time.tv_sec)
1100                 printf("%-9.9s",
1101                     sec2str(ertm->rtm_ri.ri_rcv_expire - time.tv_sec));
1102         else
1103                 printf("%-9.9s", "expired");
1104
1105         if (if_indextoname(sdl->sdl_index, ifname) == NULL)
1106                 snprintf(ifname, sizeof (ifname), "%s", "?");
1107         printf(" %8.8s", ifname);
1108
1109         if (ertm->rtm_ri.ri_refcnt) {
1110                 printf(" %4d", ertm->rtm_ri.ri_refcnt);
1111                 if (ertm->rtm_ri.ri_probes)
1112                         printf(" %4d", ertm->rtm_ri.ri_probes);
1113
1114                 if (xflag) {
1115                         if (!ertm->rtm_ri.ri_probes)
1116                                 printf(" %-4.4s", "none");
1117
1118                         if (ertm->rtm_ri.ri_rssi != IFNET_RSSI_UNKNOWN)
1119                                 printf(" %7d", ertm->rtm_ri.ri_rssi);
1120                         else
1121                                 printf(" %-7.7s", "unknown");
1122
1123                         switch (ertm->rtm_ri.ri_lqm)
1124                         {
1125                         case IFNET_LQM_THRESH_OFF:
1126                                 printf(" %-7.7s", "off");
1127                                 break;
1128                         case IFNET_LQM_THRESH_UNKNOWN:
1129                                 printf(" %-7.7s", "unknown");
1130                                 break;
1131                         case IFNET_LQM_THRESH_POOR:
1132                                 printf(" %-7.7s", "poor");
1133                                 break;
1134                         case IFNET_LQM_THRESH_GOOD:
1135                                 printf(" %-7.7s", "good");
1136                                 break;
1137                         default:
1138                                 printf(" %7d", ertm->rtm_ri.ri_lqm);
1139                                 break;
1140                         }
1141
1142                         switch (ertm->rtm_ri.ri_npm)
1143                         {
1144                         case IFNET_NPM_THRESH_UNKNOWN:
1145                                 printf(" %-7.7s", "unknown");
1146                                 break;
1147                         case IFNET_NPM_THRESH_NEAR:
1148                                 printf(" %-7.7s", "near");
1149                                 break;
1150                         case IFNET_NPM_THRESH_GENERAL:
1151                                 printf(" %-7.7s", "general");
1152                                 break;
1153                         case IFNET_NPM_THRESH_FAR:
1154                                 printf(" %-7.7s", "far");
1155                                 break;
1156                         default:
1157                                 printf(" %7d", ertm->rtm_ri.ri_npm);
1158                                 break;
1159                         }
1160                 }
1161         }
1162         printf("\n");
1163 }