networking/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 1.16 2001/11/10 11:22:43 andersen 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/ioctl.h>
  38 #include <net/if_arp.h>
  39 #include <netinet/in.h>
  40 #include <linux/if_ether.h>
  41 #include <net/if.h>
  42 #include "inet_common.h"
  43 #include "busybox.h"
  44
  45 #ifdef CONFIG_FEATURE_IFCONFIG_SLIP
  46 #include <linux/if_slip.h>
  47 #endif
  48
  49 /* I don't know if this is needed for busybox or not.  Anyone? */
  50 #define QUESTIONABLE_ALIAS_CASE
  51
  52
  53 /* Defines for glibc2.0 users. */
  54 #ifndef SIOCSIFTXQLEN
  55 #define SIOCSIFTXQLEN      0x8943
  56 #define SIOCGIFTXQLEN      0x8942
  57 #endif
  58
  59 /* ifr_qlen is ifru_ivalue, but it isn't present in 2.0 kernel headers */
  60 #ifndef ifr_qlen
  61 #define ifr_qlen        ifr_ifru.ifru_mtu
  62 #endif
  63
  64 #ifndef IFF_DYNAMIC
  65 #define IFF_DYNAMIC     0x8000  /* dialup device with changing addresses */
  66 #endif
  67
  68 /*
  69  * Here are the bit masks for the "flags" member of struct options below.
  70  * N_ signifies no arg prefix; M_ signifies arg prefixed by '-'.
  71  * CLR clears the flag; SET sets the flag; ARG signifies (optional) arg.
  72  */
  73 #define N_CLR            0x01
  74 #define M_CLR            0x02
  75 #define N_SET            0x04
  76 #define M_SET            0x08
  77 #define N_ARG            0x10
  78 #define M_ARG            0x20
  79
  80 #define M_MASK           (M_CLR | M_SET | M_ARG)
  81 #define N_MASK           (N_CLR | N_SET | N_ARG)
  82 #define SET_MASK         (N_SET | M_SET)
  83 #define CLR_MASK         (N_CLR | M_CLR)
  84 #define SET_CLR_MASK     (SET_MASK | CLR_MASK)
  85 #define ARG_MASK         (M_ARG | N_ARG)
  86
  87 /*
  88  * Here are the bit masks for the "arg_flags" member of struct options below.
  89  */
  90
  91 /*
  92  * cast type:
  93  *   00 int
  94  *   01 char *
  95  *   02 HOST_COPY in_ether
  96  *   03 HOST_COPY INET_resolve
  97  */
  98 #define A_CAST_TYPE      0x03
  99 /*
 100  * map type:
 101  *   00 not a map type (mem_start, io_addr, irq)
 102  *   04 memstart (unsigned long)
 103  *   08 io_addr  (unsigned short)
 104  *   0C irq      (unsigned char)
 105  */
 106 #define A_MAP_TYPE       0x0C
 107 #define A_ARG_REQ        0x10   /* Set if an arg is required. */
 108 #define A_NETMASK        0x20   /* Set if netmask (check for multiple sets). */
 109 #define A_SET_AFTER      0x40   /* Set a flag at the end. */
 110 #define A_COLON_CHK      0x80   /* Is this needed?  See below. */
 111
 112 /*
 113  * These defines are for dealing with the A_CAST_TYPE field.
 114  */
 115 #define A_CAST_CHAR_PTR  0x01
 116 #define A_CAST_RESOLVE   0x01
 117 #define A_CAST_HOST_COPY 0x02
 118 #define A_CAST_HOST_COPY_IN_ETHER    A_CAST_HOST_COPY
 119 #define A_CAST_HOST_COPY_RESOLVE     (A_CAST_HOST_COPY | A_CAST_RESOLVE)
 120
 121 /*
 122  * These defines are for dealing with the A_MAP_TYPE field.
 123  */
 124 #define A_MAP_ULONG      0x04   /* memstart */
 125 #define A_MAP_USHORT     0x08   /* io_addr */
 126 #define A_MAP_UCHAR      0x0C   /* irq */
 127
 128 /*
 129  * Define the bit masks signifying which operations to perform for each arg.
 130  */
 131
 132 #define ARG_METRIC       (A_ARG_REQ /*| A_CAST_INT*/)
 133 #define ARG_MTU          (A_ARG_REQ /*| A_CAST_INT*/)
 134 #define ARG_TXQUEUELEN   (A_ARG_REQ /*| A_CAST_INT*/)
 135 #define ARG_MEM_START    (A_ARG_REQ | A_MAP_ULONG)
 136 #define ARG_IO_ADDR      (A_ARG_REQ | A_MAP_ULONG)
 137 #define ARG_IRQ          (A_ARG_REQ | A_MAP_UCHAR)
 138 #define ARG_DSTADDR      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE)
 139 #define ARG_NETMASK      (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_NETMASK)
 140 #define ARG_BROADCAST    (A_ARG_REQ | A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 141 #define ARG_HW           (A_ARG_REQ | A_CAST_HOST_COPY_IN_ETHER)
 142 #define ARG_POINTOPOINT  (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER)
 143 #define ARG_KEEPALIVE    (A_ARG_REQ | A_CAST_CHAR_PTR)
 144 #define ARG_OUTFILL      (A_ARG_REQ | A_CAST_CHAR_PTR)
 145 #define ARG_HOSTNAME     (A_CAST_HOST_COPY_RESOLVE | A_SET_AFTER | A_COLON_CHK)
 146
 147
 148 /*
 149  * Set up the tables.  Warning!  They must have corresponding order!
 150  */
 151
 152 struct arg1opt {
 153         const char *name;
 154         unsigned short selector;
 155         unsigned short ifr_offset;
 156 };
 157
 158 struct options {
 159         const char *name;
 160         const unsigned char flags;
 161         const unsigned char arg_flags;
 162         const unsigned short selector;
 163 };
 164
 165 #define ifreq_offsetof(x)  offsetof(struct ifreq, x)
 166
 167 static const struct arg1opt Arg1Opt[] = {
 168         {"SIOCSIFMETRIC",  SIOCSIFMETRIC,  ifreq_offsetof(ifr_metric)},
 169         {"SIOCSIFMTU",     SIOCSIFMTU,     ifreq_offsetof(ifr_mtu)},
 170         {"SIOCSIFTXQLEN",  SIOCSIFTXQLEN,  ifreq_offsetof(ifr_qlen)},
 171         {"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
 172         {"SIOCSIFNETMASK", SIOCSIFNETMASK, ifreq_offsetof(ifr_netmask)},
 173         {"SIOCSIFBRDADDR", SIOCSIFBRDADDR, ifreq_offsetof(ifr_broadaddr)},
 174 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 175         {"SIOCSIFHWADDR",  SIOCSIFHWADDR,  ifreq_offsetof(ifr_hwaddr)},
 176 #endif
 177         {"SIOCSIFDSTADDR", SIOCSIFDSTADDR, ifreq_offsetof(ifr_dstaddr)},
 178 #ifdef SIOCSKEEPALIVE
 179         {"SIOCSKEEPALIVE", SIOCSKEEPALIVE, ifreq_offsetof(ifr_data)},
 180 #endif
 181 #ifdef SIOCSOUTFILL
 182         {"SIOCSOUTFILL",   SIOCSOUTFILL,   ifreq_offsetof(ifr_data)},
 183 #endif
 184 #ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 185         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.mem_start)},
 186         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.base_addr)},
 187         {"SIOCSIFMAP",     SIOCSIFMAP,     ifreq_offsetof(ifr_map.irq)},
 188 #endif
 189         /* Last entry if for unmatched (possibly hostname) arg. */
 190         {"SIOCSIFADDR",    SIOCSIFADDR,    ifreq_offsetof(ifr_addr)},
 191 };
 192
 193 static const struct options OptArray[] = {
 194         {"metric",       N_ARG,         ARG_METRIC,      0},
 195     {"mtu",          N_ARG,         ARG_MTU,         0},
 196         {"txqueuelen",   N_ARG,         ARG_TXQUEUELEN,  0},
 197         {"dstaddr",      N_ARG,         ARG_DSTADDR,     0},
 198         {"netmask",      N_ARG,         ARG_NETMASK,     0},
 199         {"broadcast",    N_ARG | M_CLR, ARG_BROADCAST,   IFF_BROADCAST},
 200 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 201         {"hw",           N_ARG,         ARG_HW,          0},
 202 #endif
 203         {"pointopoint",  N_ARG | M_CLR, ARG_POINTOPOINT, IFF_POINTOPOINT},
 204 #ifdef SIOCSKEEPALIVE
 205         {"keepalive",    N_ARG,         ARG_KEEPALIVE,   0},
 206 #endif
 207 #ifdef SIOCSOUTFILL
 208         {"outfill",      N_ARG,         ARG_OUTFILL,     0},
 209 #endif
 210 #ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 211         {"mem_start",    N_ARG,         ARG_MEM_START,   0},
 212         {"io_addr",      N_ARG,         ARG_IO_ADDR,     0},
 213         {"irq",          N_ARG,         ARG_IRQ,         0},
 214 #endif
 215         {"arp",          N_CLR | M_SET, 0,               IFF_NOARP},
 216         {"trailers",     N_CLR | M_SET, 0,               IFF_NOTRAILERS},
 217         {"promisc",      N_SET | M_CLR, 0,               IFF_PROMISC},
 218         {"multicast",    N_SET | M_CLR, 0,               IFF_MULTICAST},
 219         {"allmulti",     N_SET | M_CLR, 0,               IFF_ALLMULTI},
 220         {"dynamic",      N_SET | M_CLR, 0,               IFF_DYNAMIC},
 221         {"up",           N_SET        , 0,               (IFF_UP | IFF_RUNNING)},
 222         {"down",         N_CLR        , 0,               IFF_UP},
 223         { NULL,          0,             ARG_HOSTNAME,    (IFF_UP | IFF_RUNNING)}
 224 };
 225
 226 /*
 227  * A couple of prototypes.
 228  */
 229
 230 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 231 static int in_ether(char *bufp, struct sockaddr *sap);
 232 #endif
 233
 234 #ifdef CONFIG_FEATURE_IFCONFIG_STATUS
 235 extern int interface_opt_a;
 236 extern int display_interfaces(char *ifname);
 237 #endif
 238
 239 /*
 240  * Our main function.
 241  */
 242
 243 int ifconfig_main(int argc, char **argv)
 244 {
 245         struct ifreq ifr;
 246         struct sockaddr_in sai;
 247 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 248         struct sockaddr sa;
 249 #endif
 250         const struct arg1opt *a1op;
 251         const struct options *op;
 252         int sockfd;  /* socket fd we use to manipulate stuff with */
 253         int goterr;
 254         int selector;
 255         char *p;
 256         char host[128];
 257         unsigned char mask;
 258         unsigned char did_flags;
 259
 260         goterr = 0;
 261         did_flags = 0;
 262
 263         /* skip argv[0] */
 264         ++argv;
 265         --argc;
 266
 267 #ifdef CONFIG_FEATURE_IFCONFIG_STATUS
 268         if ((argc > 0) && (strcmp(*argv,"-a") == 0)) {
 269                 interface_opt_a = 1;
 270                 --argc;
 271                 ++argv;
 272         }
 273 #endif
 274
 275         if(argc <= 1) {
 276 #ifdef CONFIG_FEATURE_IFCONFIG_STATUS
 277                 return display_interfaces(argc ? *argv : NULL);
 278 #else
 279                 error_msg_and_die( "ifconfig was not compiled with interface status display support.");
 280 #endif
 281         }
 282
 283         /* Create a channel to the NET kernel. */
 284         if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 285                 perror_msg_and_die("socket");
 286         }
 287
 288         /* get interface name */
 289         safe_strncpy(ifr.ifr_name, *argv, IFNAMSIZ);
 290
 291         /* Process the remaining arguments. */
 292         while (*++argv != (char *) NULL) {
 293                 p = *argv;
 294                 mask = N_MASK;
 295                 if (*p == '-') {                /* If the arg starts with '-'... */
 296                         ++p;                            /*    advance past it and */
 297                         mask = M_MASK;          /*    set the appropriate mask. */
 298                 }
 299                 for (op = OptArray ; op->name ; op++) { /* Find table entry. */
 300                         if (strcmp(p,op->name) == 0) { /* If name matches... */
 301                                 if ((mask &= op->flags)) { /* set the mask and go. */
 302                                     goto FOUND_ARG;;
 303                                 }
 304                                 /* If we get here, there was a valid arg with an */
 305                                 /* invalid '-' prefix. */
 306                                 ++goterr;
 307                                 goto LOOP;
 308                         }
 309                 }
 310
 311                 /* We fell through, so treat as possible hostname. */
 312                 a1op = Arg1Opt + (sizeof(Arg1Opt) / sizeof(Arg1Opt[0])) - 1;
 313                 mask = op->arg_flags;
 314                 goto HOSTNAME;
 315
 316         FOUND_ARG:
 317                 if (mask & ARG_MASK) {
 318                         mask = op->arg_flags;
 319                         a1op = Arg1Opt + (op - OptArray);
 320                         if (mask & A_NETMASK & did_flags) {
 321                                 show_usage();
 322                         }
 323                         if (*++argv == NULL) {
 324                                 if (mask & A_ARG_REQ) {
 325                                         show_usage();
 326                                 } else {
 327                                         --argv;
 328                                         mask &= A_SET_AFTER; /* just for broadcast */
 329                                 }
 330                         } else {                        /* got an arg so process it */
 331                         HOSTNAME:
 332                                 did_flags |= (mask & A_NETMASK);
 333                                 if (mask & A_CAST_HOST_COPY) {
 334 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 335                                         if (mask & A_CAST_RESOLVE) {
 336 #endif
 337                                                 safe_strncpy(host, *argv, (sizeof host));
 338                                                 sai.sin_family = AF_INET;
 339                                                 sai.sin_port = 0;
 340                                                 if (!strcmp(host, bb_INET_default)) {
 341                                                         /* Default is special, meaning 0.0.0.0. */
 342                                                         sai.sin_addr.s_addr = INADDR_ANY;
 343                                                 } else if (inet_aton(host, &sai.sin_addr) == 0) {
 344                                                         /* It's not a dotted quad. */
 345                                                         ++goterr;
 346                                                         continue;
 347                                                 }
 348                                                 p = (char *) &sai;
 349 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 350                                         } else { /* A_CAST_HOST_COPY_IN_ETHER */
 351                                                 /* This is the "hw" arg case. */
 352                                                 if (strcmp("ether", *argv) || (*++argv == NULL)) {
 353                                                         show_usage();
 354                                                 }
 355                                                 safe_strncpy(host, *argv, (sizeof host));
 356                                                 if (in_ether(host, &sa)) {
 357                                                         error_msg("invalid hw-addr %s", host);
 358                                                         ++goterr;
 359                                                         continue;
 360                                                 }
 361                                                 p = (char *) &sa;
 362                                         }
 363 #endif
 364                                         memcpy((((char *)(&ifr)) + a1op->ifr_offset),
 365                                                    p, sizeof(struct sockaddr));
 366                                 } else {
 367                                         unsigned int i = strtoul(*argv,NULL,0);
 368                                         p = ((char *)(&ifr)) + a1op->ifr_offset;
 369 #ifdef CONFIG_FEATURE_IFCONFIG_MEMSTART_IOADDR_IRQ
 370                                         if (mask & A_MAP_TYPE) {
 371                                                 if (ioctl(sockfd, SIOCGIFMAP, &ifr) < 0) {
 372                                                         ++goterr;
 373                                                         continue;
 374                                                 }
 375                                                 if ((mask & A_MAP_UCHAR) == A_MAP_UCHAR) {
 376                                                         *((unsigned char *) p) = i;
 377                                                 } else if (mask & A_MAP_USHORT) {
 378                                                         *((unsigned short *) p) = i;
 379                                                 } else {
 380                                                         *((unsigned long *) p) = i;
 381                                                 }
 382                                         } else
 383 #endif
 384                                         if (mask & A_CAST_CHAR_PTR) {
 385                                                 *((caddr_t *) p) = (caddr_t) i;
 386                                         } else { /* A_CAST_INT */
 387                                                 *((int *) p) = i;
 388                                         }
 389                                 }
 390
 391                                 if (ioctl(sockfd, a1op->selector, &ifr) < 0) {
 392                                         perror(a1op->name);
 393                                         ++goterr;
 394                                         continue;
 395                                 }
 396
 397 #ifdef QUESTIONABLE_ALIAS_CASE
 398                                 if (mask & A_COLON_CHK) {
 399                                         /*
 400                                          * Don't do the set_flag() if the address is an alias with
 401                                          * a - at the end, since it's deleted already! - Roman
 402                                          *
 403                                          * Should really use regex.h here, not sure though how well
 404                                          * it'll go with the cross-platform support etc.
 405                                          */
 406                                         char *ptr;
 407                                         short int found_colon = 0;
 408                                         for (ptr = ifr.ifr_name; *ptr; ptr++ ) {
 409                                                 if (*ptr == ':') {
 410                                                         found_colon++;
 411                                                 }
 412                                         }
 413
 414                                         if (found_colon && *(ptr - 1) == '-') {
 415                                                 continue;
 416                                         }
 417                                 }
 418 #endif
 419                         }
 420                         if (!(mask & A_SET_AFTER)) {
 421                                 continue;
 422                         }
 423                         mask = N_SET;
 424                 }
 425
 426                 if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) {
 427                         perror("SIOCGIFFLAGS");
 428                         ++goterr;
 429                 } else {
 430                         selector = op->selector;
 431                         if (mask & SET_MASK) {
 432                                 ifr.ifr_flags |= selector;
 433                         } else {
 434                                 ifr.ifr_flags &= ~selector;
 435                         }
 436                         if (ioctl(sockfd, SIOCSIFFLAGS, &ifr) < 0) {
 437                                 perror("SIOCSIFFLAGS");
 438                                 ++goterr;
 439                         }
 440                 }
 441         LOOP:
 442         } /* end of while-loop */
 443
 444         return goterr;
 445 }
 446
 447 #ifdef CONFIG_FEATURE_IFCONFIG_HW
 448 /* Input an Ethernet address and convert to binary. */
 449 static int
 450 in_ether(char *bufp, struct sockaddr *sap)
 451 {
 452         unsigned char *ptr;
 453         int i, j;
 454         unsigned char val;
 455         unsigned char c;
 456
 457         sap->sa_family = ARPHRD_ETHER;
 458         ptr = sap->sa_data;
 459
 460         for (i = 0 ; i < ETH_ALEN ; i++) {
 461                 val = 0;
 462
 463                 /* We might get a semicolon here - not required. */
 464                 if (i && (*bufp == ':')) {
 465                         bufp++;
 466                 }
 467
 468                 for (j=0 ; j<2 ; j++) {
 469                         c = *bufp;
 470                         if (c >= '0' && c <= '9') {
 471                                 c -= '0';
 472                         } else if (c >= 'a' && c <= 'f') {
 473                                 c -= ('a' - 10);
 474                         } else if (c >= 'A' && c <= 'F') {
 475                                 c -= ('A' - 10);
 476                         } else if (j && (c == ':' || c == 0)) {
 477                                 break;
 478                         } else {
 479                                 return -1;
 480                         }
 481                         ++bufp;
 482                         val <<= 4;
 483                         val += c;
 484                 }
 485                 *ptr++ = val;
 486         }
 487
 488         return (int) (*bufp);           /* Error if we don't end at end of string. */
 489 }
 490 #endif