ifconfig.c

   1 /* ifconfig
   2  *
   3  * Similar to the standard Unix ifconfig, but with only the necessary
   4  * parts for AF_INET, and without any printing of if info (for now).
   5  *
   6  * Bjorn Wesen, Axis Communications AB
   7  *
   8  *
   9  * Authors of the original ifconfig was:
  10  *              Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
  11  *
  12  * This program is free software; you can redistribute it
  13  * and/or  modify it under  the terms of  the GNU General
  14  * Public  License as  published  by  the  Free  Software
  15  * Foundation;  either  version 2 of the License, or  (at
  16  * your option) any later version.
  17  *
  18  * $Id: ifconfig.c,v 1.12 2001/08/10 06:02:23 mjn3 Exp $
  19  *
  20  */
  21
  22 /*
  23  * Heavily modified by Manuel Novoa III       Mar 6, 2001
  24  *
  25  * From initial port to busybox, removed most of the redundancy by
  26  * converting to a table-driven approach.  Added several (optional)
  27  * args missing from initial port.
  28  *
  29  * Still missing:  media, tunnel.
  30  */
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>   // strcmp and friends
  35 #include <ctype.h>    // isdigit and friends
  36 #include <stddef.h>                             /* offsetof */
  37 #include <sys/types.h>
  38 #include <sys/socket.h>
  39 #include <sys/ioctl.h>
  40 #include <netinet/in.h>
  41 #include <arpa/inet.h>
  42 #include <net/if.h>
  43 #include <net/if_arp.h>
  44 #include <linux/if_ether.h>
  45 #include "busybox.h"
  46
  47 #ifdef BB_FEATURE_IFCONFIG_SLIP
  48 #include <linux/if_slip.h>
  49 #endif
  50
  51 /* I don't know if this is needed for busybox or not.  Anyone? */
  52 #define QUESTIONABLE_ALIAS_CASE
  53
  54
  55 /* Defines for glibc2.0 users. */
  56 #ifndef SIOCSIFTXQLEN
  57 #define SIOCSIFTXQLEN      0x8943
  58 #define SIOCGIFTXQLEN      0x8942
  59 #endif
  60
  61 /* ifr_qlen is ifru_ivalue, but it isn't present in 2.0 kernel headers */
  62 #ifndef ifr_qlen
  63 #define ifr_qlen        ifr_ifru.ifru_mtu
  64 #endif
  65
  66 #ifndef IFF_DYNAMIC
  67 #define IFF_DYNAMIC     0x8000  /* dialup device with changing addresses */
  68 #endif
  69
  70 /*
  71  * Here are the bit masks for the "flags" member of struct options below.
  72  * N_ signifies no arg prefix; M_ signifies arg prefixed by '-'.
  73  * CLR clears the flag; SET sets the flag; ARG signifies (optional) arg.
  74  */
  75 #define N_CLR            0x01
  76 #define M_CLR            0x02
  77 #define N_SET            0x04
  78 #define M_SET            0x08
  79 #define N_ARG            0x10
  80 #define M_ARG            0x20
  81
  82 #define M_MASK           (M_CLR | M_SET | M_ARG)
  83 #define N_MASK           (N_CLR | N_SET | N_ARG)
  84 #define SET_MASK         (N_SET | M_SET)
  85 #define CLR_MASK         (N_CLR | M_CLR)
  86 #define SET_CLR_MASK     (SET_MASK | CLR_MASK)
  87 #define ARG_MASK         (M_ARG | N_ARG)
  88
  89 /*
  90  * Here are the bit masks for the "arg_flags" member of struct options below.
  91  */
  92
  93 /*
  94  * cast type:
  95  *   00 int
  96  *   01 char *
  97  *   02 HOST_COPY in_ether
  98  *   03 HOST_COPY INET_resolve
  99  */
 100 #define A_CAST_TYPE      0x03
 101 /*
 102  * map type:
 103  *   00 not a map type (mem_start, io_addr, irq)
 104  *   04 memstart (unsigned long)
 105  *   08 io_addr  (unsigned short)
 106  *   0C irq      (unsigned char)
 107  */
 108 #define A_MAP_TYPE       0x0C
 109 #define A_ARG_REQ        0x10   /* Set if an arg is required. */
 110 #define A_NETMASK        0x20   /* Set if netmask (check for multiple sets). */
 111 #define A_SET_AFTER      0x40   /* Set a flag at the end. */
 112 #define A_COLON_CHK      0x80   /* Is this needed?  See below. */
 113
 114 /*
 115  * These defines are for dealing with the A_CAST_TYPE field.
 116  */
 117 #define A_CAST_CHAR_PTR  0x01
 118 #define A_CAST_RESOLVE   0x01
 119 #define A_CAST_HOST_COPY 0x02
 120 #define A_CAST_HOST_COPY_IN_ETHER    A_CAST_HOST_COPY
 121 #define A_CAST_HOST_COPY_RESOLVE     (A_CAST_HOST_COPY | A_CAST_RESOLVE)
 122
 123 /*
 124  * These defines are for dealing with the A_MAP_TYPE field.
 125  */
 126 #define A_MAP_ULONG      0x04   /* memstart */
 127 #define A_MAP_USHORT     0x08   /* io_addr */
 128 #define A_MAP_UCHAR      0x0C   /* irq */
 129
 130 /*
 131  * Define the bit masks signifying which operations to perform for each arg.
 132  */
 133
 134 #define ARG_METRIC       (A_ARG_REQ /*| A_CAST_INT*/)
 135 #define ARG_MTU          (A_ARG_REQ /*| A_CAST_INT*/)
 136 #define ARG_TXQUEUELEN   (A_ARG_REQ /*| A_CAST_INT*/)
 137 #define ARG_MEM_START    (A_ARG_REQ | A_MAP_ULONG)
 138 #define ARG_IO_ADDR      (A_ARG_REQ | A_MAP_USHORT)
 139 #define ARG_IRQ          (A_ARG_REQ | A_MAP_UCHAR)
 140 #define ARG_DSTADDR      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE)
 141 #define ARG_NETMASK      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_NETMASK)
 142 #define ARG_BROADCAST    (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 143 #define ARG_HW           (A_ARG_REQ | A_CAST_HOST_COPY_IN_ETHER)
 144 #define ARG_POINTOPOINT  (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 145 #define ARG_KEEPALIVE    (A_ARG_REQ | A_CAST_CHAR_PTR)
 146 #define ARG_OUTFILL      (A_ARG_REQ | A_CAST_CHAR_PTR)
 147 #define ARG_HOSTNAME     (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_COLON_CHK)
 148
 149
 150 /*
 151  * Set up the tables.  Warning!  They must have corresponding order!
 152  */
 153
 154 struct arg1opt {
 155         const char *name;
 156         unsigned short selector;
 157         unsigned short ifr_offset;
 158 };
 159
 160 struct options {
 161         const char *name;
 162         const unsigned char flags;
 163         const unsigned char arg_flags;
 164         const unsigned short selector;
 165 };
 166
 167 #define ifreq_offsetof(x)  offsetof(struct ifreq, x)
 168
 169 static const struct arg1opt Arg1Opt[] = {
 170         {"SIOCSIFMETRIC",  SIOCSIFMETRIC,  ifreq_offsetof(ifr_metric)},
 171         {"SIOCSIFMTU",     SIOCSIFMTU,     ifreq_offsetof(ifr_mtu)},
 172         {"SIOCSIFTXQLEN",  SIOCSIFTXQLEN,  ifreq_offsetof(ifr_qlen)},
 173         {"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
 174         {"SIOCSIFNETMASK", SIOCSIFNETMASK, ifreq_offsetof(ifr_netmask)},
 175         {"SIOCSIFBRDADDR", SIOCSIFBRDADDR, ifreq_offsetof(ifr_broadaddr)},
 176 #ifdef BB_FEATURE_IFCONFIG_HW
 177         {"SIOCSIFHWADDR",  SIOCSIFHWADDR,  ifreq_offsetof(ifr_hwaddr)},
 178 #endif
 179         {"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
 180 #ifdef SIOCSKEEPALIVE
 181         {"SIOCSKEEPALIVE", SIOCSKEEPALIVE, ifreq_offsetof(ifr_data)},
 182 #endif
 183 #ifdef SIOCSOUTFILL
 184         {"SIOCSOUTFILL",   SIOCSOUTFILL,   ifreq_offsetof(ifr_data)},
 185 #endif
 186 #ifdef BB_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 187         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.mem_start)},
 188         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.base_addr)},
 189         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.irq)},
 190 #endif
 191         /* Last entry if for unmatched (possibly hostname) arg. */
 192         {"SIOCSIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr)},
 193 };
 194
 195 static const struct options OptArray[] = {
 196         {"metric",       N_ARG,         ARG_METRIC,      0},
 197     {"mtu",          N_ARG,         ARG_MTU,         0},
 198         {"txqueuelen",   N_ARG,         ARG_TXQUEUELEN,  0},
 199         {"dstaddr",      N_ARG,         ARG_DSTADDR,     0},
 200         {"netmask",      N_ARG,         ARG_NETMASK,     0},
 201         {"broadcast",    N_ARG | M_CLR, ARG_BROADCAST,   IFF_BROADCAST},
 202 #ifdef BB_FEATURE_IFCONFIG_HW
 203         {"hw",           N_ARG,         ARG_HW,          0},
 204 #endif
 205         {"pointopoint",  N_ARG | M_CLR, ARG_POINTOPOINT, IFF_POINTOPOINT},
 206 #ifdef SIOCSKEEPALIVE
 207         {"keepalive",    N_ARG,         ARG_KEEPALIVE,   0},
 208 #endif
 209 #ifdef SIOCSOUTFILL
 210         {"outfill",      N_ARG,         ARG_OUTFILL,     0},
 211 #endif
 212 #ifdef BB_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 213         {"mem_start",    N_ARG,         ARG_MEM_START,   0},
 214         {"io_addr",      N_ARG,         ARG_IO_ADDR,     0},
 215         {"irq",          N_ARG,         ARG_IRQ,         0},
 216 #endif
 217         {"arp",          N_CLR | M_SET, 0,               IFF_NOARP},
 218         {"trailers",     N_CLR | M_SET, 0,               IFF_NOTRAILERS},
 219         {"promisc",      N_SET | M_CLR, 0,               IFF_PROMISC},
 220         {"multicast",    N_SET | M_CLR, 0,               IFF_MULTICAST},
 221         {"allmulti",     N_SET | M_CLR, 0,               IFF_ALLMULTI},
 222         {"dynamic",      N_SET | M_CLR, 0,               IFF_DYNAMIC},
 223         {"up",           N_SET        , 0,               (IFF_UP | IFF_RUNNING)},
 224         {"down",         N_CLR        , 0,               IFF_UP},
 225         { NULL,          0,             ARG_HOSTNAME,    (IFF_UP | IFF_RUNNING)}
 226 };
 227
 228 /*
 229  * A couple of prototypes.
 230  */
 231
 232 #ifdef BB_FEATURE_IFCONFIG_HW
 233 static int in_ether(char *bufp, struct sockaddr *sap);
 234 #endif
 235
 236 #ifdef BB_FEATURE_IFCONFIG_STATUS
 237 extern int interface_opt_a;
 238 extern int display_interfaces(char *ifname);
 239 #endif
 240
 241 /*
 242  * Our main function.
 243  */
 244
 245 int ifconfig_main(int argc, char **argv)
 246 {
 247         struct ifreq ifr;
 248         struct sockaddr_in sai;
 249 #ifdef BB_FEATURE_IFCONFIG_HW
 250         struct sockaddr sa;
 251 #endif
 252         const struct arg1opt *a1op;
 253         const struct options *op;
 254         int sockfd;  /* socket fd we use to manipulate stuff with */
 255         int goterr;
 256         int selector;
 257         char *p;
 258         char host[128];
 259         unsigned char mask;
 260         unsigned char did_flags;
 261
 262         goterr = 0;
 263         did_flags = 0;
 264
 265         /* skip argv[0] */
 266         ++argv;
 267         --argc;
 268
 269 #ifdef BB_FEATURE_IFCONFIG_STATUS
 270         if ((argc > 0) && (strcmp(*argv,"-a") == 0)) {
 271                 interface_opt_a = 1;
 272                 --argc;
 273                 ++argv;
 274         }
 275 #endif
 276
 277         if(argc <= 1) {
 278 #ifdef BB_FEATURE_IFCONFIG_STATUS
 279                 return display_interfaces(argc ? *argv : NULL);
 280 #else
 281                 error_msg_and_die( "ifconfig was not compiled with interface status display support.");
 282 #endif
 283         }
 284
 285         /* Create a channel to the NET kernel. */
 286         if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 287                 perror_msg_and_die("socket");
 288         }
 289
 290         /* get interface name */
 291         safe_strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
 292
 293         /* Process the remaining arguments. */
 294         while (*++argv != (char *) NULL) {
 295                 p = *argv;
 296                 mask = N_MASK;
 297                 if (*p == '-') {                /* If the arg starts with '-'... */
 298                         ++p;                            /*    advance past it and */
 299                         mask = M_MASK;          /*    set the appropriate mask. */
 300                 }
 301                 for (op = OptArray ; op->name ; op++) { /* Find table entry. */
 302                         if (strcmp(p,op->name) == 0) { /* If name matches... */
 303                                 if ((mask &= op->flags)) { /* set the mask and go. */
 304                                     goto FOUND_ARG;;
 305                                 }
 306                                 /* If we get here, there was a valid arg with an */
 307                                 /* invalid '-' prefix. */
 308                                 ++goterr;
 309                                 goto LOOP;
 310                         }
 311                 }
 312
 313                 /* We fell through, so treat as possible hostname. */
 314                 a1op = Arg1Opt + (sizeof(Arg1Opt) / sizeof(Arg1Opt[0])) - 1;
 315                 mask = op->arg_flags;
 316                 goto HOSTNAME;
 317
 318         FOUND_ARG:
 319                 if (mask & ARG_MASK) {
 320                         mask = op->arg_flags;
 321                         a1op = Arg1Opt + (op - OptArray);
 322                         if (mask & A_NETMASK & did_flags) {
 323                                 show_usage();
 324                         }
 325                         if (*++argv == NULL) {
 326                                 if (mask & A_ARG_REQ) {
 327                                         show_usage();
 328                                 } else {
 329                                         --argv;
 330                                         mask &= A_SET_AFTER; /* just for broadcast */
 331                                 }
 332                         } else {                        /* got an arg so process it */
 333                         HOSTNAME:
 334                                 did_flags |= (mask & A_NETMASK);
 335                                 if (mask & A_CAST_HOST_COPY) {
 336 #ifdef BB_FEATURE_IFCONFIG_HW
 337                                         if (mask & A_CAST_RESOLVE) {
 338 #endif
 339                                                 safe_strncpy(host, *argv, (sizeof host));
 340                                                 sai.sin_family = AF_INET;
 341                                                 sai.sin_port = 0;
 342                                                 if (!strcmp(host, "default")) {
 343                                                         /* Default is special, meaning 0.0.0.0. */
 344                                                         sai.sin_addr.s_addr = INADDR_ANY;
 345                                                 } else if (inet_aton(host, &sai.sin_addr) == 0) {
 346                                                         /* It's not a dotted quad. */
 347                                                         ++goterr;
 348                                                         continue;
 349                                                 }
 350                                                 p = (char *) &sai;
 351 #ifdef BB_FEATURE_IFCONFIG_HW
 352                                         } else { /* A_CAST_HOST_COPY_IN_ETHER */
 353                                                 /* This is the "hw" arg case. */
 354                                                 if (strcmp("ether", *argv) || (*++argv == NULL)) {
 355                                                         show_usage();
 356                                                 }
 357                                                 safe_strncpy(host, *argv, (sizeof host));
 358                                                 if (in_ether(host, &sa)) {
 359                                                         fprintf(stderr, "invalid hw-addr %s\n", host);
 360                                                         ++goterr;
 361                                                         continue;
 362                                                 }
 363                                                 p = (char *) &sa;
 364                                         }
 365 #endif
 366                                         memcpy((((char *)(&ifr)) + a1op->ifr_offset),
 367                                                    p, sizeof(struct sockaddr));
 368                                 } else {
 369                                         unsigned int i = strtoul(*argv,NULL,0);
 370                                         p = ((char *)(&ifr)) + a1op->ifr_offset;
 371 #ifdef BB_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 372                                         if (mask & A_MAP_TYPE) {
 373                                                 if (ioctl(sockfd, SIOCGIFMAP, &ifr) < 0) {
 374                                                         ++goterr;
 375                                                         continue;
 376                                                 }
 377                                                 if ((mask & A_MAP_UCHAR) == A_MAP_UCHAR) {
 378                                                         *((unsigned char *) p) = i;
 379                                                 } else if (mask & A_MAP_USHORT) {
 380                                                         *((unsigned short *) p) = i;
 381                                                 } else {
 382                                                         *((unsigned long *) p) = i;
 383                                                 }
 384                                         } else
 385 #endif
 386                                         if (mask & A_CAST_CHAR_PTR) {
 387                                                 *((caddr_t *) p) = (caddr_t) i;
 388                                         } else { /* A_CAST_INT */
 389                                                 *((int *) p) = i;
 390                                         }
 391                                 }
 392
 393                                 if (ioctl(sockfd, a1op->selector, &ifr) < 0) {
 394                                         perror(a1op->name);
 395                                         ++goterr;
 396                                         continue;
 397                                 }
 398
 399 #ifdef QUESTIONABLE_ALIAS_CASE
 400                                 if (mask & A_COLON_CHK) {
 401                                         /*
 402                                          * Don't do the set_flag() if the address is an alias with
 403                                          * a - at the end, since it's deleted already! - Roman
 404                                          *
 405                                          * Should really use regex.h here, not sure though how well
 406                                          * it'll go with the cross-platform support etc.
 407                                          */
 408                                         char *ptr;
 409                                         short int found_colon = 0;
 410                                         for (ptr = ifr.ifr_name; *ptr; ptr++ ) {
 411                                                 if (*ptr == ':') {
 412                                                         found_colon++;
 413                                                 }
 414                                         }
 415
 416                                         if (found_colon && *(ptr - 1) == '-') {
 417                                                 continue;
 418                                         }
 419                                 }
 420 #endif
 421                         }
 422                         if (!(mask & A_SET_AFTER)) {
 423                                 continue;
 424                         }
 425                         mask = N_SET;
 426                 }
 427
 428                 if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) {
 429                         perror("SIOCGIFFLAGS");
 430                         ++goterr;
 431                 } else {
 432                         selector = op->selector;
 433                         if (mask & SET_MASK) {
 434                                 ifr.ifr_flags |= selector;
 435                         } else {
 436                                 ifr.ifr_flags &= ~selector;
 437                         }
 438                         if (ioctl(sockfd, SIOCSIFFLAGS, &ifr) < 0) {
 439                                 perror("SIOCSIFFLAGS");
 440                                 ++goterr;
 441                         }
 442                 }
 443         LOOP:
 444         } /* end of while-loop */
 445
 446         return goterr;
 447 }
 448
 449 #ifdef BB_FEATURE_IFCONFIG_HW
 450 /* Input an Ethernet address and convert to binary. */
 451 static int
 452 in_ether(char *bufp, struct sockaddr *sap)
 453 {
 454         unsigned char *ptr;
 455         int i, j;
 456         unsigned char val;
 457         unsigned char c;
 458
 459         sap->sa_family = ARPHRD_ETHER;
 460         ptr = sap->sa_data;
 461
 462         for (i = 0 ; i < ETH_ALEN ; i++) {
 463                 val = 0;
 464
 465                 /* We might get a semicolon here - not required. */
 466                 if (i && (*bufp == ':')) {
 467                         bufp++;
 468                 }
 469
 470                 for (j=0 ; j<2 ; j++) {
 471                         c = *bufp;
 472                         if (c >= '0' && c <= '9') {
 473                                 c -= '0';
 474                         } else if (c >= 'a' && c <= 'f') {
 475                                 c -= ('a' - 10);
 476                         } else if (c >= 'A' && c <= 'F') {
 477                                 c -= ('A' - 10);
 478                         } else if (j && (c == ':' || c == 0)) {
 479                                 break;
 480                         } else {
 481                                 return -1;
 482                         }
 483                         ++bufp;
 484                         val <<= 4;
 485                         val += c;
 486                 }
 487                 *ptr++ = val;
 488         }
 489
 490         return (int) (*bufp);           /* Error if we don't end at end of string. */
 491 }
 492 #endif