arp.tproj/arp.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1984, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software contributed to Berkeley by
  29  * Sun Microsystems, Inc.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  43  * 4. Neither the name of the University nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  */
  59
  60 #ifndef lint
  61 static char copyright[] =
  62 "@(#) Copyright (c) 1984, 1993\n\
  63         The Regents of the University of California.  All rights reserved.\n";
  64 #endif /* not lint */
  65
  66 #ifndef lint
  67 static char sccsid[] = "@(#)arp.c       8.3 (Berkeley) 4/28/95";
  68 #endif /* not lint */
  69
  70 /*
  71  * arp - display, set, and delete arp table entries
  72  */
  73
  74
  75 #include <sys/param.h>
  76 #include <sys/file.h>
  77 #include <sys/socket.h>
  78 #include <sys/sysctl.h>
  79
  80 #include <net/if.h>
  81 #include <net/if_dl.h>
  82 #include <net/if_types.h>
  83 #include <net/route.h>
  84
  85 #include <netinet/in.h>
  86 #include <netinet/if_ether.h>
  87
  88 #include <arpa/inet.h>
  89
  90 #include <err.h>
  91 #include <errno.h>
  92 #include <netdb.h>
  93 #include <nlist.h>
  94 #include <paths.h>
  95 #include <stdio.h>
  96 #include <stdlib.h>
  97 #include <string.h>
  98 #include <unistd.h>
  99
 100 static int pid;
 101 static int nflag;
 102 static int s = -1;
 103
 104 int     delete __P((char *, char *));
 105 void    dump __P((u_long));
 106 int     ether_aton __P((char *, u_char *));
 107 void    ether_print __P((u_char *));
 108 int     file __P((char *));
 109 void    get __P((char *));
 110 void    getsocket __P((void));
 111 int     rtmsg __P((int));
 112 int     set __P((int, char **));
 113 void    usage __P((void));
 114
 115 int
 116 main(argc, argv)
 117         int argc;
 118         char **argv;
 119 {
 120         int ch;
 121
 122         pid = getpid();
 123         while ((ch = getopt(argc, argv, "ands")) != EOF)
 124                 switch((char)ch) {
 125                 case 'a':
 126                         dump(0);
 127                         exit(0);
 128                 case 'd':
 129                         if (argc < 3 || argc > 4)
 130                                 usage();
 131                         delete(argv[2], argv[3]);
 132                         exit(0);
 133                 case 'n':
 134                         nflag = 1;
 135                         continue;
 136                 case 's':
 137                         if (argc < 4 || argc > 7)
 138                                 usage();
 139                         exit(set(argc-2, &argv[2]) ? 1 : 0);
 140                 case '?':
 141                 default:
 142                         usage();
 143                 }
 144         if (argc != 2)
 145                 usage();
 146         get(argv[1]);
 147         return (0);
 148 }
 149
 150 /*
 151  * Process a file to set standard arp entries
 152  */
 153 int
 154 file(name)
 155         char *name;
 156 {
 157         FILE *fp;
 158         int i, retval;
 159         char line[100], arg[5][50], *args[5];
 160
 161         if ((fp = fopen(name, "r")) == NULL) {
 162                 fprintf(stderr, "arp: cannot open %s\n", name);
 163                 exit(1);
 164         }
 165         args[0] = &arg[0][0];
 166         args[1] = &arg[1][0];
 167         args[2] = &arg[2][0];
 168         args[3] = &arg[3][0];
 169         args[4] = &arg[4][0];
 170         retval = 0;
 171         while(fgets(line, 100, fp) != NULL) {
 172                 i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1], arg[2],
 173                     arg[3], arg[4]);
 174                 if (i < 2) {
 175                         fprintf(stderr, "arp: bad line: %s\n", line);
 176                         retval = 1;
 177                         continue;
 178                 }
 179                 if (set(i, args))
 180                         retval = 1;
 181         }
 182         fclose(fp);
 183         return (retval);
 184 }
 185
 186 void
 187 getsocket() {
 188         if (s < 0) {
 189                 s = socket(PF_ROUTE, SOCK_RAW, 0);
 190                 if (s < 0) {
 191                         perror("arp: socket");
 192                         exit(1);
 193                 }
 194         }
 195 }
 196
 197 struct  sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
 198 struct  sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
 199 struct  sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
 200 int     expire_time, flags, export_only, doing_proxy, found_entry;
 201 struct  {
 202         struct  rt_msghdr m_rtm;
 203         char    m_space[512];
 204 }       m_rtmsg;
 205
 206 /*
 207  * Set an individual arp entry
 208  */
 209 int
 210 set(argc, argv)
 211         int argc;
 212         char **argv;
 213 {
 214         struct hostent *hp;
 215         register struct sockaddr_inarp *sin = &sin_m;
 216         register struct sockaddr_dl *sdl;
 217         register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
 218         u_char *ea;
 219         char *host = argv[0], *eaddr = argv[1];
 220
 221         getsocket();
 222         argc -= 2;
 223         argv += 2;
 224         sdl_m = blank_sdl;
 225         sin_m = blank_sin;
 226         sin->sin_addr.s_addr = inet_addr(host);
 227         if (sin->sin_addr.s_addr == -1) {
 228                 if (!(hp = gethostbyname(host))) {
 229                         fprintf(stderr, "arp: %s: ", host);
 230                         herror((char *)NULL);
 231                         return (1);
 232                 }
 233                 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 234                     sizeof sin->sin_addr);
 235         }
 236         ea = (u_char *)LLADDR(&sdl_m);
 237         if (ether_aton(eaddr, ea) == 0)
 238                 sdl_m.sdl_alen = 6;
 239         doing_proxy = flags = export_only = expire_time = 0;
 240         while (argc-- > 0) {
 241                 if (strncmp(argv[0], "temp", 4) == 0) {
 242                         struct timeval time;
 243                         gettimeofday(&time, 0);
 244                         expire_time = time.tv_sec + 20 * 60;
 245                 }
 246                 else if (strncmp(argv[0], "pub", 3) == 0) {
 247                         flags |= RTF_ANNOUNCE;
 248                         doing_proxy = SIN_PROXY;
 249                 } else if (strncmp(argv[0], "trail", 5) == 0) {
 250                         printf("%s: Sending trailers is no longer supported\n",
 251                                 host);
 252                 }
 253                 argv++;
 254         }
 255 tryagain:
 256         if (rtmsg(RTM_GET) < 0) {
 257                 perror(host);
 258                 return (1);
 259         }
 260         sin = (struct sockaddr_inarp *)(rtm + 1);
 261         sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
 262         if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
 263                 if (sdl->sdl_family == AF_LINK &&
 264                     (rtm->rtm_flags & RTF_LLINFO) &&
 265                     !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
 266                 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
 267                 case IFT_ISO88024: case IFT_ISO88025:
 268                         goto overwrite;
 269                 }
 270                 if (doing_proxy == 0) {
 271                         printf("set: can only proxy for %s\n", host);
 272                         return (1);
 273                 }
 274                 if (sin_m.sin_other & SIN_PROXY) {
 275                         printf("set: proxy entry exists for non 802 device\n");
 276                         return(1);
 277                 }
 278                 sin_m.sin_other = SIN_PROXY;
 279                 export_only = 1;
 280                 goto tryagain;
 281         }
 282 overwrite:
 283         if (sdl->sdl_family != AF_LINK) {
 284                 printf("cannot intuit interface index and type for %s\n", host);
 285                 return (1);
 286         }
 287         sdl_m.sdl_type = sdl->sdl_type;
 288         sdl_m.sdl_index = sdl->sdl_index;
 289         return (rtmsg(RTM_ADD));
 290 }
 291
 292 /*
 293  * Display an individual arp entry
 294  */
 295 void
 296 get(host)
 297         char *host;
 298 {
 299         struct hostent *hp;
 300         struct sockaddr_inarp *sin = &sin_m;
 301
 302         sin_m = blank_sin;
 303         sin->sin_addr.s_addr = inet_addr(host);
 304         if (sin->sin_addr.s_addr == -1) {
 305                 if (!(hp = gethostbyname(host))) {
 306                         fprintf(stderr, "arp: %s: ", host);
 307                         herror((char *)NULL);
 308                         exit(1);
 309                 }
 310                 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 311                     sizeof sin->sin_addr);
 312         }
 313         dump(sin->sin_addr.s_addr);
 314         if (found_entry == 0) {
 315                 printf("%s (%s) -- no entry\n",
 316                     host, inet_ntoa(sin->sin_addr));
 317                 exit(1);
 318         }
 319 }
 320
 321 /*
 322  * Delete an arp entry
 323  */
 324 int
 325 delete(host, info)
 326         char *host;
 327         char *info;
 328 {
 329         struct hostent *hp;
 330         register struct sockaddr_inarp *sin = &sin_m;
 331         register struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
 332         struct sockaddr_dl *sdl;
 333
 334         if (info && strncmp(info, "pro", 3) )
 335                 export_only = 1;
 336         getsocket();
 337         sin_m = blank_sin;
 338         sin->sin_addr.s_addr = inet_addr(host);
 339         if (sin->sin_addr.s_addr == -1) {
 340                 if (!(hp = gethostbyname(host))) {
 341                         fprintf(stderr, "arp: %s: ", host);
 342                         herror((char *)NULL);
 343                         return (1);
 344                 }
 345                 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 346                     sizeof sin->sin_addr);
 347         }
 348 tryagain:
 349         if (rtmsg(RTM_GET) < 0) {
 350                 perror(host);
 351                 return (1);
 352         }
 353         sin = (struct sockaddr_inarp *)(rtm + 1);
 354         sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
 355         if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
 356                 if (sdl->sdl_family == AF_LINK &&
 357                     (rtm->rtm_flags & RTF_LLINFO) &&
 358                     !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
 359                 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
 360                 case IFT_ISO88024: case IFT_ISO88025:
 361                         goto delete;
 362                 }
 363         }
 364         if (sin_m.sin_other & SIN_PROXY) {
 365                 fprintf(stderr, "delete: can't locate %s\n",host);
 366                 return (1);
 367         } else {
 368                 sin_m.sin_other = SIN_PROXY;
 369                 goto tryagain;
 370         }
 371 delete:
 372         if (sdl->sdl_family != AF_LINK) {
 373                 printf("cannot locate %s\n", host);
 374                 return (1);
 375         }
 376         if (rtmsg(RTM_DELETE))
 377                 return (1);
 378         printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));
 379         return (0);
 380 }
 381
 382 /*
 383  * Dump the entire arp table
 384  */
 385 void
 386 dump(addr)
 387         u_long addr;
 388 {
 389         int mib[6];
 390         size_t needed;
 391         char *host, *lim, *buf, *next;
 392         struct rt_msghdr *rtm;
 393         struct sockaddr_inarp *sin;
 394         struct sockaddr_dl *sdl;
 395         extern int h_errno;
 396         struct hostent *hp;
 397
 398         mib[0] = CTL_NET;
 399         mib[1] = PF_ROUTE;
 400         mib[2] = 0;
 401         mib[3] = AF_INET;
 402         mib[4] = NET_RT_FLAGS;
 403         mib[5] = RTF_LLINFO;
 404         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 405                 err(1, "route-sysctl-estimate");
 406         if ((buf = malloc(needed)) == NULL)
 407                 err(1, "malloc");
 408         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 409                 err(1, "actual retrieval of routing table");
 410         lim = buf + needed;
 411         for (next = buf; next < lim; next += rtm->rtm_msglen) {
 412                 rtm = (struct rt_msghdr *)next;
 413                 sin = (struct sockaddr_inarp *)(rtm + 1);
 414                 sdl = (struct sockaddr_dl *)(sin + 1);
 415                 if (addr) {
 416                         if (addr != sin->sin_addr.s_addr)
 417                                 continue;
 418                         found_entry = 1;
 419                 }
 420                 if (nflag == 0)
 421                         hp = gethostbyaddr((caddr_t)&(sin->sin_addr),
 422                             sizeof sin->sin_addr, AF_INET);
 423                 else
 424                         hp = 0;
 425                 if (hp)
 426                         host = hp->h_name;
 427                 else {
 428                         host = "?";
 429                         if (h_errno == TRY_AGAIN)
 430                                 nflag = 1;
 431                 }
 432                 printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr));
 433                 if (sdl->sdl_alen)
 434                         ether_print((u_char *)LLADDR(sdl));
 435                 else
 436                         printf("(incomplete)");
 437                 if (rtm->rtm_rmx.rmx_expire == 0)
 438                         printf(" permanent");
 439                 if (sin->sin_other & SIN_PROXY)
 440                         printf(" published (proxy only)");
 441                 if (rtm->rtm_addrs & RTA_NETMASK) {
 442                         sin = (struct sockaddr_inarp *)
 443                                 (sdl->sdl_len + (char *)sdl);
 444                         if (sin->sin_addr.s_addr == 0xffffffff)
 445                                 printf(" published");
 446                         if (sin->sin_len != 8)
 447                                 printf("(wierd)");
 448                 }
 449                 printf("\n");
 450         }
 451 }
 452
 453 void
 454 ether_print(cp)
 455         u_char *cp;
 456 {
 457         printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
 458 }
 459
 460 int
 461 ether_aton(a, n)
 462         char *a;
 463         u_char *n;
 464 {
 465         int i, o[6];
 466
 467         i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2],
 468                                            &o[3], &o[4], &o[5]);
 469         if (i != 6) {
 470                 fprintf(stderr, "arp: invalid Ethernet address '%s'\n", a);
 471                 return (1);
 472         }
 473         for (i=0; i<6; i++)
 474                 n[i] = o[i];
 475         return (0);
 476 }
 477
 478 void
 479 usage()
 480 {
 481         printf("usage: arp hostname\n");
 482         printf("       arp -a [kernel] [kernel_memory]\n");
 483         printf("       arp -d hostname\n");
 484         printf("       arp -s hostname ether_addr [temp] [pub]\n");
 485         printf("       arp -f filename\n");
 486         exit(1);
 487 }
 488
 489 int
 490 rtmsg(cmd)
 491         int cmd;
 492 {
 493         static int seq;
 494         int rlen;
 495         register struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
 496         register char *cp = m_rtmsg.m_space;
 497         register int l;
 498
 499         errno = 0;
 500         if (cmd == RTM_DELETE)
 501                 goto doit;
 502         bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
 503         rtm->rtm_flags = flags;
 504         rtm->rtm_version = RTM_VERSION;
 505
 506         switch (cmd) {
 507         default:
 508                 fprintf(stderr, "arp: internal wrong cmd\n");
 509                 exit(1);
 510         case RTM_ADD:
 511                 rtm->rtm_addrs |= RTA_GATEWAY;
 512                 rtm->rtm_rmx.rmx_expire = expire_time;
 513                 rtm->rtm_inits = RTV_EXPIRE;
 514                 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
 515                 sin_m.sin_other = 0;
 516                 if (doing_proxy) {
 517                         if (export_only)
 518                                 sin_m.sin_other = SIN_PROXY;
 519                         else {
 520                                 rtm->rtm_addrs |= RTA_NETMASK;
 521                                 rtm->rtm_flags &= ~RTF_HOST;
 522                         }
 523                 }
 524                 /* FALLTHROUGH */
 525         case RTM_GET:
 526                 rtm->rtm_addrs |= RTA_DST;
 527         }
 528 #define NEXTADDR(w, s) \
 529         if (rtm->rtm_addrs & (w)) { \
 530                 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);}
 531
 532         NEXTADDR(RTA_DST, sin_m);
 533         NEXTADDR(RTA_GATEWAY, sdl_m);
 534         NEXTADDR(RTA_NETMASK, so_mask);
 535
 536         rtm->rtm_msglen = cp - (char *)&m_rtmsg;
 537 doit:
 538         l = rtm->rtm_msglen;
 539         rtm->rtm_seq = ++seq;
 540         rtm->rtm_type = cmd;
 541         if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
 542                 if (errno != ESRCH || cmd != RTM_DELETE) {
 543                         perror("writing to routing socket");
 544                         return (-1);
 545                 }
 546         }
 547         do {
 548                 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
 549         } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
 550         if (l < 0)
 551                 (void) fprintf(stderr, "arp: read from routing socket: %s\n",
 552                     strerror(errno));
 553         return (0);
 554 }