arp.c

   1 /*
   2  * arp                This file contains an implementation of the command
   3  *              that maintains the kernel's ARP cache.  It is derived
   4  *              from Berkeley UNIX arp(8), but cleaner and with sup-
   5  *              port for devices other than Ethernet.
   6  *
   7  * NET-TOOLS    A collection of programs that form the base set of the
   8  *              NET-3 Networking Distribution for the LINUX operating
   9  *              system.
  10  *
  11  * Version:     $Id: arp.c,v 1.18 2000/11/06 19:48:49 pb Exp $
  12  *
  13  * Maintainer:  Bernd 'eckes' Eckenfels, <net-tools@lina.inka.de>
  14  *
  15  * Author:      Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  16  *
  17  * Changes:
  18  *              (based on work from Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>)
  19  *              Alan Cox        :       modified for NET3
  20  *              Andrew Tridgell :       proxy arp netmasks
  21  *              Bernd Eckenfels :       -n option
  22  *              Bernd Eckenfels :       Use only /proc for display
  23  *       {1.60} Bernd Eckenfels :       new arpcode (-i) for 1.3.42 but works
  24  *                                      with 1.2.x, too
  25  *       {1.61} Bernd Eckenfels :       more verbose messages
  26  *       {1.62} Bernd Eckenfels :       check -t for hw adresses and try to
  27  *                                      explain EINVAL (jeff)
  28  *970125 {1.63} Bernd Eckenfels :       -a print hardwarename instead of tiltle
  29  *970201 {1.64} Bernd Eckenfels :       net-features.h support
  30  *970203 {1.65} Bernd Eckenfels :       "#define" in "#if",
  31  *                                      -H|-A additional to -t|-p
  32  *970214 {1.66} Bernd Eckenfels :       Fix optarg required for -H and -A
  33  *970412 {1.67} Bernd Eckenfels :       device=""; is default
  34  *970514 {1.68} Bernd Eckenfels :       -N and -D
  35  *970517 {1.69} Bernd Eckenfels :       usage() fixed
  36  *970622 {1.70} Bernd Eckenfels :       arp -d priv
  37  *970106 {1.80} Bernd Eckenfels :       new syntax without -D and with "dev <If>",
  38  *                                      ATF_MAGIC, ATF_DONTPUB support.
  39  *                                      Typo fix (Debian Bug#5728 Giuliano Procida)
  40  *970803 {1.81} Bernd Eckenfels :       removed junk comment line 1
  41  *970925 {1.82} Bernd Eckenfels :       include fix for libc6
  42  *980213 (1.83) Phil Blundell:          set ATF_COM on new entries
  43  *980629 (1.84) Arnaldo Carvalho de Melo: gettext instead of catgets
  44  *990101 {1.85} Bernd Eckenfels         fixed usage and return codes
  45  *990105 (1.86) Phil Blundell:          don't ignore EINVAL in arp_set
  46  *991121 (1.87) Bernd Eckenfels:        yes --device has a mandatory arg
  47  *
  48  *              This program is free software; you can redistribute it
  49  *              and/or  modify it under  the terms of  the GNU General
  50  *              Public  License as  published  by  the  Free  Software
  51  *              Foundation;  either  version 2 of the License, or  (at
  52  *              your option) any later version.
  53  */
  54 #include <sys/types.h>
  55 #include <sys/socket.h>
  56 #include <sys/ioctl.h>
  57 #include <net/if.h>
  58 /* #include <linux/netdevice.h> */
  59 /* #include <linux/if_arp.h>    */
  60 #include <net/if_arp.h>
  61 #include <stdlib.h>
  62 #include <stdio.h>
  63 #include <errno.h>
  64 #include <ctype.h>
  65 #include <fcntl.h>
  66 #include <string.h>
  67 #include <getopt.h>
  68 #include <unistd.h>
  69 #include "net-support.h"
  70 #include "pathnames.h"
  71 #include "version.h"
  72 #include "config.h"
  73 #include "intl.h"
  74 #include "util.h"
  75
  76 #define DFLT_AF "inet"
  77 #define DFLT_HW "ether"
  78
  79 #define FEATURE_ARP
  80 #include "lib/net-features.h"
  81
  82 char *Release = RELEASE, *Version = "arp 1.87 (1999-11-21)";
  83
  84 int opt_n = 0;                  /* do not resolve addresses     */
  85 int opt_N = 0;                  /* use symbolic names           */
  86 int opt_v = 0;                  /* debugging output flag        */
  87 int opt_D = 0;                  /* HW-address is devicename     */
  88 int opt_e = 0;                  /* 0=BSD output, 1=new linux    */
  89 int opt_a = 0;                  /* all entries, substring match */
  90 struct aftype *ap;              /* current address family       */
  91 struct hwtype *hw;              /* current hardware type        */
  92 int sockfd = 0;                 /* active socket descriptor     */
  93 int hw_set = 0;                 /* flag if hw-type was set (-H) */
  94 char device[16] = "";           /* current device               */
  95 static void usage(void);
  96
  97 /* Delete an entry from the ARP cache. */
  98 static int arp_del(char **args)
  99 {
 100     char host[128];
 101     struct arpreq req;
 102     struct sockaddr sa;
 103     int flags = 0;
 104     int err;
 105
 106     memset((char *) &req, 0, sizeof(req));
 107
 108     /* Resolve the host name. */
 109     if (*args == NULL) {
 110         fprintf(stderr, _("arp: need host name\n"));
 111         return (-1);
 112     }
 113     safe_strncpy(host, *args, (sizeof host));
 114     if (ap->input(0, host, &sa) < 0) {
 115         ap->herror(host);
 116         return (-1);
 117     }
 118     /* If a host has more than one address, use the correct one! */
 119     memcpy((char *) &req.arp_pa, (char *) &sa, sizeof(struct sockaddr));
 120
 121     if (hw_set)
 122         req.arp_ha.sa_family = hw->type;
 123
 124     req.arp_flags = ATF_PERM;
 125     args++;
 126     while (*args != NULL) {
 127         if (opt_v)
 128             fprintf(stderr, "args=%s\n", *args);
 129         if (!strcmp(*args, "pub")) {
 130             flags |= 1;
 131             args++;
 132             continue;
 133         }
 134         if (!strcmp(*args, "priv")) {
 135             flags |= 2;
 136             args++;
 137             continue;
 138         }
 139         if (!strcmp(*args, "temp")) {
 140             req.arp_flags &= ~ATF_PERM;
 141             args++;
 142             continue;
 143         }
 144         if (!strcmp(*args, "trail")) {
 145             req.arp_flags |= ATF_USETRAILERS;
 146             args++;
 147             continue;
 148         }
 149         if (!strcmp(*args, "dontpub")) {
 150 #ifdef HAVE_ATF_DONTPUB
 151             req.arp_flags |= ATF_DONTPUB;
 152 #else
 153             ENOSUPP("arp", "ATF_DONTPUB");
 154 #endif
 155             args++;
 156             continue;
 157         }
 158         if (!strcmp(*args, "auto")) {
 159 #ifdef HAVE_ATF_MAGIC
 160             req.arp_flags |= ATF_MAGIC;
 161 #else
 162             ENOSUPP("arp", "ATF_MAGIC");
 163 #endif
 164             args++;
 165             continue;
 166         }
 167         if (!strcmp(*args, "dev")) {
 168             if (*++args == NULL)
 169                 usage();
 170             safe_strncpy(device, *args, sizeof(device));
 171             args++;
 172             continue;
 173         }
 174         if (!strcmp(*args, "netmask")) {
 175             if (*++args == NULL)
 176                 usage();
 177             if (strcmp(*args, "255.255.255.255") != 0) {
 178                 strcpy(host, *args);
 179                 if (ap->input(0, host, &sa) < 0) {
 180                     ap->herror(host);
 181                     return (-1);
 182                 }
 183                 memcpy((char *) &req.arp_netmask, (char *) &sa,
 184                        sizeof(struct sockaddr));
 185                 req.arp_flags |= ATF_NETMASK;
 186             }
 187             args++;
 188             continue;
 189         }
 190         usage();
 191     }
 192     if (flags == 0)
 193         flags = 3;
 194
 195     strcpy(req.arp_dev, device);
 196
 197     err = -1;
 198
 199     /* Call the kernel. */
 200     if (flags & 2) {
 201         if (opt_v)
 202             fprintf(stderr, "arp: SIOCDARP(nopub)\n");
 203         if ((err = ioctl(sockfd, SIOCDARP, &req) < 0)) {
 204             if (errno == ENXIO) {
 205                 if (flags & 1)
 206                     goto nopub;
 207                 printf(_("No ARP entry for %s\n"), host);
 208                 return (-1);
 209             }
 210             perror("SIOCDARP(priv)");
 211             return (-1);
 212         }
 213     }
 214     if ((flags & 1) && (err)) {
 215       nopub:
 216         req.arp_flags |= ATF_PUBL;
 217         if (opt_v)
 218             fprintf(stderr, "arp: SIOCDARP(pub)\n");
 219         if (ioctl(sockfd, SIOCDARP, &req) < 0) {
 220             if (errno == ENXIO) {
 221                 printf(_("No ARP entry for %s\n"), host);
 222                 return (-1);
 223             }
 224             perror("SIOCDARP(pub)");
 225             return (-1);
 226         }
 227     }
 228     return (0);
 229 }
 230
 231 /* Get the hardware address to a specified interface name */
 232 static int arp_getdevhw(char *ifname, struct sockaddr *sa, struct hwtype *hw)
 233 {
 234     struct ifreq ifr;
 235     struct hwtype *xhw;
 236
 237     strcpy(ifr.ifr_name, ifname);
 238     if (ioctl(sockfd, SIOCGIFHWADDR, &ifr) < 0) {
 239         fprintf(stderr, _("arp: cant get HW-Address for `%s': %s.\n"), ifname, strerror(errno));
 240         return (-1);
 241     }
 242     if (hw && (ifr.ifr_hwaddr.sa_family != hw->type)) {
 243         fprintf(stderr, _("arp: protocol type mismatch.\n"));
 244         return (-1);
 245     }
 246     memcpy((char *) sa, (char *) &(ifr.ifr_hwaddr), sizeof(struct sockaddr));
 247
 248     if (opt_v) {
 249         if (!(xhw = get_hwntype(ifr.ifr_hwaddr.sa_family)) || (xhw->print == 0)) {
 250             xhw = get_hwntype(-1);
 251         }
 252         fprintf(stderr, _("arp: device `%s' has HW address %s `%s'.\n"), ifname, xhw->name, xhw->print((char *)&ifr.ifr_hwaddr.sa_data));
 253     }
 254     return (0);
 255 }
 256
 257 /* Set an entry in the ARP cache. */
 258 static int arp_set(char **args)
 259 {
 260     char host[128];
 261     struct arpreq req;
 262     struct sockaddr sa;
 263     int flags;
 264
 265     memset((char *) &req, 0, sizeof(req));
 266
 267     /* Resolve the host name. */
 268     if (*args == NULL) {
 269         fprintf(stderr, _("arp: need host name\n"));
 270         return (-1);
 271     }
 272     safe_strncpy(host, *args++, (sizeof host));
 273     if (ap->input(0, host, &sa) < 0) {
 274         ap->herror(host);
 275         return (-1);
 276     }
 277     /* If a host has more than one address, use the correct one! */
 278     memcpy((char *) &req.arp_pa, (char *) &sa, sizeof(struct sockaddr));
 279
 280     /* Fetch the hardware address. */
 281     if (*args == NULL) {
 282         fprintf(stderr, _("arp: need hardware address\n"));
 283         return (-1);
 284     }
 285     if (opt_D) {
 286         if (arp_getdevhw(*args++, &req.arp_ha, hw_set ? hw : NULL) < 0)
 287             return (-1);
 288     } else {
 289         if (hw->input(*args++, &req.arp_ha) < 0) {
 290             fprintf(stderr, _("arp: invalid hardware address\n"));
 291             return (-1);
 292         }
 293     }
 294
 295     /* Check out any modifiers. */
 296     flags = ATF_PERM | ATF_COM;
 297     while (*args != NULL) {
 298         if (!strcmp(*args, "temp")) {
 299             flags &= ~ATF_PERM;
 300             args++;
 301             continue;
 302         }
 303         if (!strcmp(*args, "pub")) {
 304             flags |= ATF_PUBL;
 305             args++;
 306             continue;
 307         }
 308         if (!strcmp(*args, "priv")) {
 309             flags &= ~ATF_PUBL;
 310             args++;
 311             continue;
 312         }
 313         if (!strcmp(*args, "trail")) {
 314             flags |= ATF_USETRAILERS;
 315             args++;
 316             continue;
 317         }
 318         if (!strcmp(*args, "dontpub")) {
 319 #ifdef HAVE_ATF_DONTPUB
 320             flags |= ATF_DONTPUB;
 321 #else
 322             ENOSUPP("arp", "ATF_DONTPUB");
 323 #endif
 324             args++;
 325             continue;
 326         }
 327         if (!strcmp(*args, "auto")) {
 328 #ifdef HAVE_ATF_MAGIC
 329             flags |= ATF_MAGIC;
 330 #else
 331             ENOSUPP("arp", "ATF_MAGIC");
 332 #endif
 333             args++;
 334             continue;
 335         }
 336         if (!strcmp(*args, "dev")) {
 337             if (*++args == NULL)
 338                 usage();
 339             safe_strncpy(device, *args, sizeof(device));
 340             args++;
 341             continue;
 342         }
 343         if (!strcmp(*args, "netmask")) {
 344             if (*++args == NULL)
 345                 usage();
 346             if (strcmp(*args, "255.255.255.255") != 0) {
 347                 strcpy(host, *args);
 348                 if (ap->input(0, host, &sa) < 0) {
 349                     ap->herror(host);
 350                     return (-1);
 351                 }
 352                 memcpy((char *) &req.arp_netmask, (char *) &sa,
 353                        sizeof(struct sockaddr));
 354                 flags |= ATF_NETMASK;
 355             }
 356             args++;
 357             continue;
 358         }
 359         usage();
 360     }
 361
 362     /* Fill in the remainder of the request. */
 363     req.arp_flags = flags;
 364
 365     strcpy(req.arp_dev, device);
 366
 367     /* Call the kernel. */
 368     if (opt_v)
 369         fprintf(stderr, "arp: SIOCSARP()\n");
 370     if (ioctl(sockfd, SIOCSARP, &req) < 0) {
 371         perror("SIOCSARP");
 372         return (-1);
 373     }
 374     return (0);
 375 }
 376
 377
 378 /* Process an EtherFile */
 379 static int arp_file(char *name)
 380 {
 381     char buff[1024];
 382     char *sp, *args[32];
 383     int linenr, argc;
 384     FILE *fp;
 385
 386     if ((fp = fopen(name, "r")) == NULL) {
 387         fprintf(stderr, _("arp: cannot open etherfile %s !\n"), name);
 388         return (-1);
 389     }
 390     /* Read the lines in the file. */
 391     linenr = 0;
 392     while (fgets(buff, sizeof(buff), fp) != (char *) NULL) {
 393         linenr++;
 394         if (opt_v == 1)
 395             fprintf(stderr, ">> %s", buff);
 396         if ((sp = strchr(buff, '\n')) != (char *) NULL)
 397             *sp = '\0';
 398         if (buff[0] == '#' || buff[0] == '\0')
 399             continue;
 400
 401         argc = getargs(buff, args);
 402         if (argc < 2) {
 403             fprintf(stderr, _("arp: format error on line %u of etherfile %s !\n"),
 404                     linenr, name);
 405             continue;
 406         }
 407         if (strchr (args[0], ':') != NULL) {
 408             /* We have a correct ethers file, switch hw adress and hostname
 409                for arp */
 410             char *cp;
 411             cp = args[1];
 412             args[1] = args[0];
 413             args[0] = cp;
 414         }
 415         if (arp_set(args) != 0)
 416             fprintf(stderr, _("arp: cannot set entry on line %u of etherfile %s !\n"),
 417                     linenr, name);
 418     }
 419
 420     (void) fclose(fp);
 421     return (0);
 422 }
 423
 424
 425 /* Print the contents of an ARP request block. */
 426 static void arp_disp_2(char *name, int type, int arp_flags, char *hwa, char *mask, char *dev)
 427 {
 428     static int title = 0;
 429     struct hwtype *xhw;
 430     char flags[10];
 431
 432     xhw = get_hwntype(type);
 433     if (xhw == NULL)
 434         xhw = get_hwtype(DFLT_HW);
 435
 436     if (title++ == 0) {
 437         printf(_("Address\t\t\tHWtype\tHWaddress\t    Flags Mask\t\t  Iface\n"));
 438     }
 439     /* Setup the flags. */
 440     flags[0] = '\0';
 441     if (arp_flags & ATF_COM)
 442         strcat(flags, "C");
 443     if (arp_flags & ATF_PERM)
 444         strcat(flags, "M");
 445     if (arp_flags & ATF_PUBL)
 446         strcat(flags, "P");
 447 #ifdef HAVE_ATF_MAGIC
 448     if (arp_flags & ATF_MAGIC)
 449         strcat(flags, "A");
 450 #endif
 451 #ifdef HAVE_ATF_DONTPUB
 452     if (arp_flags & ATF_DONTPUB)
 453         strcat(flags, "!");
 454 #endif
 455     if (arp_flags & ATF_USETRAILERS)
 456         strcat(flags, "T");
 457
 458     if (!(arp_flags & ATF_NETMASK))
 459         mask = "";
 460
 461     printf("%-23.23s\t", name);
 462
 463     if (!(arp_flags & ATF_COM)) {
 464         if (arp_flags & ATF_PUBL)
 465             printf("%-8.8s%-20.20s", "*", "*");
 466         else
 467             printf("%-8.8s%-20.20s", "", _("(incomplete)"));
 468     } else {
 469         printf("%-8.8s%-20.20s", xhw->name, hwa);
 470     }
 471
 472     printf("%-6.6s%-15.15s %s\n", flags, mask, dev);
 473 }
 474
 475 /* Print the contents of an ARP request block. */
 476 static void arp_disp(char *name, char *ip, int type, int arp_flags, char *hwa, char *mask, char *dev)
 477 {
 478     struct hwtype *xhw;
 479
 480     xhw = get_hwntype(type);
 481     if (xhw == NULL)
 482         xhw = get_hwtype(DFLT_HW);
 483
 484     printf(_("%s (%s) at "), name, ip);
 485
 486     if (!(arp_flags & ATF_COM)) {
 487         if (arp_flags & ATF_PUBL)
 488             printf("* ");
 489         else
 490             printf(_("<incomplete> "));
 491     } else {
 492         printf("%s [%s] ", hwa, xhw->name);
 493     }
 494
 495     if (arp_flags & ATF_NETMASK)
 496         printf(_("netmask %s "), mask);
 497
 498     if (arp_flags & ATF_PERM)
 499         printf("PERM ");
 500     if (arp_flags & ATF_PUBL)
 501         printf("PUP ");
 502 #ifdef HAVE_ATF_MAGIC
 503     if (arp_flags & ATF_MAGIC)
 504         printf("AUTO ");
 505 #endif
 506 #ifdef HAVE_ATF_DONTPUB
 507     if (arp_flags & ATF_DONTPUB)
 508         printf("DONTPUB ");
 509 #endif
 510     if (arp_flags & ATF_USETRAILERS)
 511         printf("TRAIL ");
 512
 513     printf(_("on %s\n"), dev);
 514 }
 515
 516
 517 /* Display the contents of the ARP cache in the kernel. */
 518 static int arp_show(char *name)
 519 {
 520     char host[100];
 521     struct sockaddr sa;
 522     char ip[100];
 523     char hwa[100];
 524     char mask[100];
 525     char line[200];
 526     char dev[100];
 527     int type, flags;
 528     FILE *fp;
 529     char *hostname;
 530     int num, entries = 0, showed = 0;
 531
 532     host[0] = '\0';
 533
 534     if (name != NULL) {
 535         /* Resolve the host name. */
 536         safe_strncpy(host, name, (sizeof host));
 537         if (ap->input(0, host, &sa) < 0) {
 538             ap->herror(host);
 539             return (-1);
 540         }
 541         safe_strncpy(host, ap->sprint(&sa, 1), sizeof(host));
 542     }
 543     /* Open the PROCps kernel table. */
 544     if ((fp = fopen(_PATH_PROCNET_ARP, "r")) == NULL) {
 545         perror(_PATH_PROCNET_ARP);
 546         return (-1);
 547     }
 548     /* Bypass header -- read until newline */
 549     if (fgets(line, sizeof(line), fp) != (char *) NULL) {
 550         strcpy(mask, "-");
 551         strcpy(dev, "-");
 552         /* Read the ARP cache entries. */
 553         for (; fgets(line, sizeof(line), fp);) {
 554             num = sscanf(line, "%s 0x%x 0x%x %100s %100s %100s\n",
 555                          ip, &type, &flags, hwa, mask, dev);
 556             if (num < 4)
 557                 break;
 558
 559             entries++;
 560             /* if the user specified hw-type differs, skip it */
 561             if (hw_set && (type != hw->type))
 562                 continue;
 563
 564             /* if the user specified address differs, skip it */
 565             if (host[0] && strcmp(ip, host))
 566                 continue;
 567
 568             /* if the user specified device differs, skip it */
 569             if (device[0] && strcmp(dev, device))
 570                 continue;
 571
 572             showed++;
 573             /* This IS ugly but it works -be */
 574             if (opt_n)
 575                 hostname = "?";
 576             else {
 577                 if (ap->input(0, ip, &sa) < 0)
 578                     hostname = ip;
 579                 else
 580                     hostname = ap->sprint(&sa, opt_n | 0x8000);
 581                 if (strcmp(hostname, ip) == 0)
 582                     hostname = "?";
 583             }
 584
 585             if (opt_e)
 586                 arp_disp_2(hostname[0] == '?' ? ip : hostname, type, flags, hwa, mask, dev);
 587             else
 588                 arp_disp(hostname, ip, type, flags, hwa, mask, dev);
 589         }
 590     }
 591     if (opt_v)
 592         printf(_("Entries: %d\tSkipped: %d\tFound: %d\n"), entries, entries - showed, showed);
 593
 594     if (!showed) {
 595         if (host[0] && !opt_a)
 596             printf(_("%s (%s) -- no entry\n"), name, host);
 597         else if (hw_set || host[0] || device[0]) {
 598             printf(_("arp: in %d entries no match found.\n"), entries);
 599         }
 600     }
 601     (void) fclose(fp);
 602     return (0);
 603 }
 604
 605 static void version(void)
 606 {
 607     fprintf(stderr, "%s\n%s\n%s\n", Release, Version, Features);
 608     exit(E_VERSION);
 609 }
 610
 611 static void usage(void)
 612 {
 613     fprintf(stderr, _("Usage:\n  arp [-vn]  [<HW>] [-i <if>] [-a] [<hostname>]             <-Display ARP cache\n"));
 614     fprintf(stderr, _("  arp [-v]          [-i <if>] -d  <hostname> [pub][nopub]    <-Delete ARP entry\n"));
 615     fprintf(stderr, _("  arp [-vnD] [<HW>] [-i <if>] -f  [<filename>]              <-Add entry from file\n"));
 616     fprintf(stderr, _("  arp [-v]   [<HW>] [-i <if>] -s  <hostname> <hwaddr> [temp][nopub] <-Add entry\n"));
 617     fprintf(stderr, _("  arp [-v]   [<HW>] [-i <if>] -s  <hostname> <hwaddr> [netmask <nm>] pub  <-''-\n"));
 618     fprintf(stderr, _("  arp [-v]   [<HW>] [-i <if>] -Ds <hostname> <if> [netmask <nm>] pub      <-''-\n\n"));
 619
 620     fprintf(stderr, _("        -a                       display (all) hosts in alternative (BSD) style\n"));
 621     fprintf(stderr, _("        -s, --set                set a new ARP entry\n"));
 622     fprintf(stderr, _("        -d, --delete             delete a specified entry\n"));
 623     fprintf(stderr, _("        -v, --verbose            be verbose\n"));
 624     fprintf(stderr, _("        -n, --numeric            don't resolve names\n"));
 625     fprintf(stderr, _("        -i, --device             specify network interface (e.g. eth0)\n"));
 626     fprintf(stderr, _("        -D, --use-device         read <hwaddr> from given device\n"));
 627     fprintf(stderr, _("        -A, -p, --protocol       specify protocol family\n"));
 628     fprintf(stderr, _("        -f, --file               read new entries from file or from /etc/ethers\n\n"));
 629
 630     fprintf(stderr, _("  <HW>=Use '-H <hw>' to specify hardware address type. Default: %s\n"), DFLT_HW);
 631     fprintf(stderr, _("  List of possible hardware types (which support ARP):\n"));
 632     print_hwlist(1); /* 1 = ARPable */
 633     exit(E_USAGE);
 634 }
 635
 636 int main(int argc, char **argv)
 637 {
 638     int i, lop, what;
 639     struct option longopts[] =
 640     {
 641         {"verbose", 0, 0, 'v'},
 642         {"version", 0, 0, 'V'},
 643         {"all", 0, 0, 'a'},
 644         {"delete", 0, 0, 'd'},
 645         {"file", 0, 0, 'f'},
 646         {"numeric", 0, 0, 'n'},
 647         {"set", 0, 0, 's'},
 648         {"protocol", 1, 0, 'A'},
 649         {"hw-type", 1, 0, 'H'},
 650         {"device", 1, 0, 'i'},
 651         {"help", 0, 0, 'h'},
 652         {"use-device", 0, 0, 'D'},
 653         {"symbolic", 0, 0, 'N'},
 654         {NULL, 0, 0, 0}
 655     };
 656
 657 #if I18N
 658     bindtextdomain("net-tools", "/usr/share/locale");
 659     textdomain("net-tools");
 660 #endif
 661
 662     /* Initialize variables... */
 663     if ((hw = get_hwtype(DFLT_HW)) == NULL) {
 664         fprintf(stderr, _("%s: hardware type not supported!\n"), DFLT_HW);
 665         return (-1);
 666     }
 667     if ((ap = get_aftype(DFLT_AF)) == NULL) {
 668         fprintf(stderr, _("%s: address family not supported!\n"), DFLT_AF);
 669         return (-1);
 670     }
 671     what = 0;
 672
 673     /* Fetch the command-line arguments. */
 674     /* opterr = 0; */
 675     while ((i = getopt_long(argc, argv, "A:H:adfp:nsei:t:vh?DNV", longopts, &lop)) != EOF)
 676         switch (i) {
 677         case 'a':
 678             what = 1;
 679             opt_a = 1;
 680             break;
 681         case 'f':
 682             what = 2;
 683             break;
 684         case 'd':
 685             what = 3;
 686             break;
 687         case 's':
 688             what = 4;
 689             break;
 690
 691
 692         case 'e':
 693             opt_e = 1;
 694             break;
 695         case 'n':
 696             opt_n = FLAG_NUM;
 697             break;
 698         case 'D':
 699             opt_D = 1;
 700             break;
 701         case 'N':
 702             opt_N = FLAG_SYM;
 703             fprintf(stderr, _("arp: -N not yet supported.\n"));
 704             break;
 705         case 'v':
 706             opt_v = 1;
 707             break;
 708
 709         case 'A':
 710         case 'p':
 711             ap = get_aftype(optarg);
 712             if (ap == NULL) {
 713                 fprintf(stderr, _("arp: %s: unknown address family.\n"),
 714                         optarg);
 715                 exit(-1);
 716             }
 717             break;
 718         case 'H':
 719         case 't':
 720             hw = get_hwtype(optarg);
 721             if (hw == NULL) {
 722                 fprintf(stderr, _("arp: %s: unknown hardware type.\n"),
 723                         optarg);
 724                 exit(-1);
 725             }
 726             hw_set = 1;
 727             break;
 728         case 'i':
 729             safe_strncpy(device, optarg, sizeof(device));
 730             break;
 731
 732         case 'V':
 733             version();
 734         case '?':
 735         case 'h':
 736         default:
 737             usage();
 738         }
 739
 740     if (ap->af != AF_INET) {
 741         fprintf(stderr, _("arp: %s: kernel only supports 'inet'.\n"),
 742                 ap->name);
 743         exit(-1);
 744     }
 745
 746     /* If not hw type specified get default */
 747     if(hw_set==0)
 748         if ((hw = get_hwtype(DFLT_HW)) == NULL) {
 749           fprintf(stderr, _("%s: hardware type not supported!\n"), DFLT_HW);
 750           return (-1);
 751         }
 752
 753     if (hw->alen <= 0) {
 754         fprintf(stderr, _("arp: %s: hardware type without ARP support.\n"),
 755                 hw->name);
 756         exit(-1);
 757     }
 758     if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 759         perror("socket");
 760         exit(-1);
 761     }
 762     /* Now see what we have to do here... */
 763     switch (what) {
 764     case 0:
 765         opt_e = 1;
 766         what = arp_show(argv[optind]);
 767         break;
 768
 769     case 1:                     /* show an ARP entry in the cache */
 770         what = arp_show(argv[optind]);
 771         break;
 772
 773     case 2:                     /* process an EtherFile */
 774         what = arp_file(argv[optind] ? argv[optind] : "/etc/ethers");
 775         break;
 776
 777     case 3:                     /* delete an ARP entry from the cache */
 778         what = arp_del(&argv[optind]);
 779         break;
 780
 781     case 4:                     /* set an ARP entry in the cache */
 782         what = arp_set(&argv[optind]);
 783         break;
 784
 785     default:
 786         usage();
 787     }
 788
 789     exit(what);
 790 }