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 aflag = 0;
 103 static int s = -1;
 104
 105 int     delete __P((char *, char *));
 106 void    dump __P((u_long));
 107 int     ether_aton __P((char *, u_char *));
 108 void    ether_print __P((u_char *));
 109 int     file __P((char *));
 110 void    get __P((char *));
 111 void    getsocket __P((void));
 112 int     rtmsg __P((int));
 113 int     set __P((int, char **));
 114 void    usage __P((void));
 115
 116 int
 117 main(argc, argv)
 118         int argc;
 119         char **argv;
 120 {
 121         int ch;
 122
 123         pid = getpid();
 124         while ((ch = getopt(argc, argv, "ands")) != EOF)
 125                 switch((char)ch) {
 126                 case 'a':
 127                         aflag = 1;
 128                         break;
 129                 case 'd':
 130                         if (argc < 3 || argc > 4)
 131                                 usage();
 132                         delete(argv[2], argv[3]);
 133                         exit(0);
 134                 case 'n':
 135                         nflag = 1;
 136                         break;
 137                 case 's':
 138                         if (argc < 4 || argc > 7)
 139                                 usage();
 140                         exit(set(argc-2, &argv[2]) ? 1 : 0);
 141                 case '?':
 142                 default:
 143                         usage();
 144                 }
 145         if( aflag ) {
 146                 dump(0);
 147                 exit(0);
 148         }
 149         if( nflag && (argc == 3) ) {
 150                 get(argv[2]);
 151                 exit(0);
 152         }
 153         if (argc != 2)
 154                 usage();
 155         get(argv[1]);
 156         return (0);
 157 }
 158
 159 /*
 160  * Process a file to set standard arp entries
 161  */
 162 int
 163 file(name)
 164         char *name;
 165 {
 166         FILE *fp;
 167         int i, retval;
 168         char line[100], arg[5][50], *args[5];
 169
 170         if ((fp = fopen(name, "r")) == NULL) {
 171                 fprintf(stderr, "arp: cannot open %s\n", name);
 172                 exit(1);
 173         }
 174         args[0] = &arg[0][0];
 175         args[1] = &arg[1][0];
 176         args[2] = &arg[2][0];
 177         args[3] = &arg[3][0];
 178         args[4] = &arg[4][0];
 179         retval = 0;
 180         while(fgets(line, 100, fp) != NULL) {
 181                 i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1], arg[2],
 182                     arg[3], arg[4]);
 183                 if (i < 2) {
 184                         fprintf(stderr, "arp: bad line: %s\n", line);
 185                         retval = 1;
 186                         continue;
 187                 }
 188                 if (set(i, args))
 189                         retval = 1;
 190         }
 191         fclose(fp);
 192         return (retval);
 193 }
 194
 195 void
 196 getsocket() {
 197         if (s < 0) {
 198                 s = socket(PF_ROUTE, SOCK_RAW, 0);
 199                 if (s < 0) {
 200                         perror("arp: socket");
 201                         exit(1);
 202                 }
 203         }
 204 }
 205
 206 struct  sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
 207 struct  sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
 208 struct  sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
 209 int     expire_time, flags, export_only, doing_proxy, found_entry;
 210 struct  {
 211         struct  rt_msghdr m_rtm;
 212         char    m_space[512];
 213 }       m_rtmsg;
 214
 215 /*
 216  * Set an individual arp entry
 217  */
 218 int
 219 set(argc, argv)
 220         int argc;
 221         char **argv;
 222 {
 223         struct hostent *hp;
 224         register struct sockaddr_inarp *sin = &sin_m;
 225         register struct sockaddr_dl *sdl;
 226         register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
 227         u_char *ea;
 228         char *host = argv[0], *eaddr = argv[1];
 229
 230         getsocket();
 231         argc -= 2;
 232         argv += 2;
 233         sdl_m = blank_sdl;
 234         sin_m = blank_sin;
 235         sin->sin_addr.s_addr = inet_addr(host);
 236         if (sin->sin_addr.s_addr == -1) {
 237                 if (!(hp = gethostbyname(host))) {
 238                         fprintf(stderr, "arp: %s: ", host);
 239                         herror((char *)NULL);
 240                         return (1);
 241                 }
 242                 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 243                     sizeof sin->sin_addr);
 244         }
 245         ea = (u_char *)LLADDR(&sdl_m);
 246         if (ether_aton(eaddr, ea) == 0)
 247                 sdl_m.sdl_alen = 6;
 248         doing_proxy = flags = export_only = expire_time = 0;
 249         while (argc-- > 0) {
 250                 if (strncmp(argv[0], "temp", 4) == 0) {
 251                         struct timeval time;
 252                         gettimeofday(&time, 0);
 253                         expire_time = time.tv_sec + 20 * 60;
 254                 }
 255                 else if (strncmp(argv[0], "pub", 3) == 0) {
 256                         flags |= RTF_ANNOUNCE;
 257                         doing_proxy = SIN_PROXY;
 258                 } else if (strncmp(argv[0], "trail", 5) == 0) {
 259                         printf("%s: Sending trailers is no longer supported\n",
 260                                 host);
 261                 }
 262                 argv++;
 263         }
 264 tryagain:
 265         if (rtmsg(RTM_GET) < 0) {
 266                 perror(host);
 267                 return (1);
 268         }
 269         sin = (struct sockaddr_inarp *)(rtm + 1);
 270         sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
 271         if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
 272                 if (sdl->sdl_family == AF_LINK &&
 273                     (rtm->rtm_flags & RTF_LLINFO) &&
 274                     !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
 275                 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
 276                 case IFT_ISO88024: case IFT_ISO88025:
 277                         goto overwrite;
 278                 }
 279                 if (doing_proxy == 0) {
 280                         printf("set: can only proxy for %s\n", host);
 281                         return (1);
 282                 }
 283                 if (sin_m.sin_other & SIN_PROXY) {
 284                         printf("set: proxy entry exists for non 802 device\n");
 285                         return(1);
 286                 }
 287                 sin_m.sin_other = SIN_PROXY;
 288                 export_only = 1;
 289                 goto tryagain;
 290         }
 291 overwrite:
 292         if (sdl->sdl_family != AF_LINK) {
 293                 printf("cannot intuit interface index and type for %s\n", host);
 294                 return (1);
 295         }
 296         sdl_m.sdl_type = sdl->sdl_type;
 297         sdl_m.sdl_index = sdl->sdl_index;
 298         return (rtmsg(RTM_ADD));
 299 }
 300
 301 /*
 302  * Display an individual arp entry
 303  */
 304 void
 305 get(host)
 306         char *host;
 307 {
 308         struct hostent *hp;
 309         struct sockaddr_inarp *sin = &sin_m;
 310
 311         sin_m = blank_sin;
 312         sin->sin_addr.s_addr = inet_addr(host);
 313         if (sin->sin_addr.s_addr == -1) {
 314                 if (!(hp = gethostbyname(host))) {
 315                         fprintf(stderr, "arp: %s: ", host);
 316                         herror((char *)NULL);
 317                         exit(1);
 318                 }
 319                 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 320                     sizeof sin->sin_addr);
 321         }
 322         dump(sin->sin_addr.s_addr);
 323         if (found_entry == 0) {
 324                 printf("%s (%s) -- no entry\n",
 325                     host, inet_ntoa(sin->sin_addr));
 326                 exit(1);
 327         }
 328 }
 329
 330 /*
 331  * Delete an arp entry
 332  */
 333 int
 334 delete(host, info)
 335         char *host;
 336         char *info;
 337 {
 338         struct hostent *hp;
 339         register struct sockaddr_inarp *sin = &sin_m;
 340         register struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
 341         struct sockaddr_dl *sdl;
 342
 343         if (info && strncmp(info, "pro", 3) )
 344                 export_only = 1;
 345         getsocket();
 346         sin_m = blank_sin;
 347         sin->sin_addr.s_addr = inet_addr(host);
 348         if (sin->sin_addr.s_addr == -1) {
 349                 if (!(hp = gethostbyname(host))) {
 350                         fprintf(stderr, "arp: %s: ", host);
 351                         herror((char *)NULL);
 352                         return (1);
 353                 }
 354                 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr,
 355                     sizeof sin->sin_addr);
 356         }
 357 tryagain:
 358         if (rtmsg(RTM_GET) < 0) {
 359                 perror(host);
 360                 return (1);
 361         }
 362         sin = (struct sockaddr_inarp *)(rtm + 1);
 363         sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
 364         if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
 365                 if (sdl->sdl_family == AF_LINK &&
 366                     (rtm->rtm_flags & RTF_LLINFO) &&
 367                     !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
 368                 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
 369                 case IFT_ISO88024: case IFT_ISO88025:
 370                         goto delete;
 371                 }
 372         }
 373         if (sin_m.sin_other & SIN_PROXY) {
 374                 fprintf(stderr, "delete: can't locate %s\n",host);
 375                 return (1);
 376         } else {
 377                 sin_m.sin_other = SIN_PROXY;
 378                 goto tryagain;
 379         }
 380 delete:
 381         if (sdl->sdl_family != AF_LINK) {
 382                 printf("cannot locate %s\n", host);
 383                 return (1);
 384         }
 385         if (rtmsg(RTM_DELETE))
 386                 return (1);
 387         printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));
 388         return (0);
 389 }
 390
 391 /*
 392  * Dump the entire arp table
 393  */
 394 void
 395 dump(addr)
 396         u_long addr;
 397 {
 398         int mib[6];
 399         size_t needed;
 400         char *host, *lim, *buf, *next;
 401         struct rt_msghdr *rtm;
 402         struct sockaddr_inarp *sin;
 403         struct sockaddr_dl *sdl;
 404         extern int h_errno;
 405         struct hostent *hp;
 406
 407         mib[0] = CTL_NET;
 408         mib[1] = PF_ROUTE;
 409         mib[2] = 0;
 410         mib[3] = AF_INET;
 411         mib[4] = NET_RT_FLAGS;
 412         mib[5] = RTF_LLINFO;
 413         if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 414                 err(1, "route-sysctl-estimate");
 415         if ((buf = malloc(needed)) == NULL)
 416                 err(1, "malloc");
 417         if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
 418                 err(1, "actual retrieval of routing table");
 419         lim = buf + needed;
 420         for (next = buf; next < lim; next += rtm->rtm_msglen) {
 421                 rtm = (struct rt_msghdr *)next;
 422                 sin = (struct sockaddr_inarp *)(rtm + 1);
 423                 sdl = (struct sockaddr_dl *)(sin + 1);
 424                 if (addr) {
 425                         if (addr != sin->sin_addr.s_addr)
 426                                 continue;
 427                         found_entry = 1;
 428                 }
 429                 if (nflag == 0)
 430                         hp = gethostbyaddr((caddr_t)&(sin->sin_addr),
 431                             sizeof sin->sin_addr, AF_INET);
 432                 else
 433                         hp = 0;
 434                 if (hp)
 435                         host = hp->h_name;
 436                 else {
 437                         host = "?";
 438                         if (h_errno == TRY_AGAIN)
 439                                 nflag = 1;
 440                 }
 441                 printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr));
 442                 if (sdl->sdl_alen)
 443                         ether_print((u_char *)LLADDR(sdl));
 444                 else
 445                         printf("(incomplete)");
 446                 if (rtm->rtm_rmx.rmx_expire == 0)
 447                         printf(" permanent");
 448                 if (sin->sin_other & SIN_PROXY)
 449                         printf(" published (proxy only)");
 450                 if (rtm->rtm_addrs & RTA_NETMASK) {
 451                         sin = (struct sockaddr_inarp *)
 452                                 (sdl->sdl_len + (char *)sdl);
 453                         if (sin->sin_addr.s_addr == 0xffffffff)
 454                                 printf(" published");
 455                         if (sin->sin_len != 8)
 456                                 printf("(wierd)");
 457                 }
 458                 printf("\n");
 459         }
 460 }
 461
 462 void
 463 ether_print(cp)
 464         u_char *cp;
 465 {
 466         printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);
 467 }
 468
 469 int
 470 ether_aton(a, n)
 471         char *a;
 472         u_char *n;
 473 {
 474         int i, o[6];
 475
 476         i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2],
 477                                            &o[3], &o[4], &o[5]);
 478         if (i != 6) {
 479                 fprintf(stderr, "arp: invalid Ethernet address '%s'\n", a);
 480                 return (1);
 481         }
 482         for (i=0; i<6; i++)
 483                 n[i] = o[i];
 484         return (0);
 485 }
 486
 487 void
 488 usage()
 489 {
 490         printf("usage: arp [-n] hostname\n");
 491         printf("       arp [-n] -a\n");
 492         printf("       arp -d hostname\n");
 493         printf("       arp -s hostname ether_addr [temp] [pub]\n");
 494         printf("       arp -f filename\n");
 495         exit(1);
 496 }
 497
 498 int
 499 rtmsg(cmd)
 500         int cmd;
 501 {
 502         static int seq;
 503         int rlen;
 504         register struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
 505         register char *cp = m_rtmsg.m_space;
 506         register int l;
 507
 508         errno = 0;
 509         if (cmd == RTM_DELETE)
 510                 goto doit;
 511         bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
 512         rtm->rtm_flags = flags;
 513         rtm->rtm_version = RTM_VERSION;
 514
 515         switch (cmd) {
 516         default:
 517                 fprintf(stderr, "arp: internal wrong cmd\n");
 518                 exit(1);
 519         case RTM_ADD:
 520                 rtm->rtm_addrs |= RTA_GATEWAY;
 521                 rtm->rtm_rmx.rmx_expire = expire_time;
 522                 rtm->rtm_inits = RTV_EXPIRE;
 523                 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
 524                 sin_m.sin_other = 0;
 525                 if (doing_proxy) {
 526                         if (export_only)
 527                                 sin_m.sin_other = SIN_PROXY;
 528                         else {
 529                                 rtm->rtm_addrs |= RTA_NETMASK;
 530                                 rtm->rtm_flags &= ~RTF_HOST;
 531                         }
 532                 }
 533                 /* FALLTHROUGH */
 534         case RTM_GET:
 535                 rtm->rtm_addrs |= RTA_DST;
 536         }
 537 #define NEXTADDR(w, s) \
 538         if (rtm->rtm_addrs & (w)) { \
 539                 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);}
 540
 541         NEXTADDR(RTA_DST, sin_m);
 542         NEXTADDR(RTA_GATEWAY, sdl_m);
 543         NEXTADDR(RTA_NETMASK, so_mask);
 544
 545         rtm->rtm_msglen = cp - (char *)&m_rtmsg;
 546 doit:
 547         l = rtm->rtm_msglen;
 548         rtm->rtm_seq = ++seq;
 549         rtm->rtm_type = cmd;
 550         if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
 551                 if (errno != ESRCH || cmd != RTM_DELETE) {
 552                         perror("writing to routing socket");
 553                         return (-1);
 554                 }
 555         }
 556         do {
 557                 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
 558         } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid));
 559         if (l < 0)
 560                 (void) fprintf(stderr, "arp: read from routing socket: %s\n",
 561                     strerror(errno));
 562         return (0);
 563 }