networking/udhcp/common.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
   4  *
   5  * Licensed under GPLv2, see file LICENSE in this source tree.
   6  */
   7 #include "common.h"
   8
   9 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
  10 unsigned dhcp_verbose;
  11 #endif
  12
  13 const uint8_t MAC_BCAST_ADDR[6] ALIGN2 = {
  14         0xff, 0xff, 0xff, 0xff, 0xff, 0xff
  15 };
  16
  17 /* Supported options are easily added here.
  18  * See RFC2132 for more options.
  19  * OPTION_REQ: these options are requested by udhcpc (unless -o).
  20  */
  21 const struct dhcp_optflag dhcp_optflags[] = {
  22         /* flags                                    code */
  23         { OPTION_IP                   | OPTION_REQ, 0x01 }, /* DHCP_SUBNET        */
  24         { OPTION_S32                              , 0x02 }, /* DHCP_TIME_OFFSET   */
  25         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x03 }, /* DHCP_ROUTER        */
  26 //      { OPTION_IP | OPTION_LIST                 , 0x04 }, /* DHCP_TIME_SERVER   */
  27 //      { OPTION_IP | OPTION_LIST                 , 0x05 }, /* DHCP_NAME_SERVER   */
  28         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x06 }, /* DHCP_DNS_SERVER    */
  29 //      { OPTION_IP | OPTION_LIST                 , 0x07 }, /* DHCP_LOG_SERVER    */
  30 //      { OPTION_IP | OPTION_LIST                 , 0x08 }, /* DHCP_COOKIE_SERVER */
  31         { OPTION_IP | OPTION_LIST                 , 0x09 }, /* DHCP_LPR_SERVER    */
  32         { OPTION_STRING               | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME     */
  33         { OPTION_U16                              , 0x0d }, /* DHCP_BOOT_SIZE     */
  34         { OPTION_STRING               | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME   */
  35         { OPTION_IP                               , 0x10 }, /* DHCP_SWAP_SERVER   */
  36         { OPTION_STRING                           , 0x11 }, /* DHCP_ROOT_PATH     */
  37         { OPTION_U8                               , 0x17 }, /* DHCP_IP_TTL        */
  38         { OPTION_U16                              , 0x1a }, /* DHCP_MTU           */
  39         { OPTION_IP                   | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST     */
  40         { OPTION_IP_PAIR | OPTION_LIST            , 0x21 }, /* DHCP_ROUTES        */
  41         { OPTION_STRING                           , 0x28 }, /* DHCP_NIS_DOMAIN    */
  42         { OPTION_IP | OPTION_LIST                 , 0x29 }, /* DHCP_NIS_SERVER    */
  43         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER    */
  44         { OPTION_IP | OPTION_LIST                 , 0x2c }, /* DHCP_WINS_SERVER   */
  45         { OPTION_U32                              , 0x33 }, /* DHCP_LEASE_TIME    */
  46         { OPTION_IP                               , 0x36 }, /* DHCP_SERVER_ID     */
  47         { OPTION_STRING                           , 0x38 }, /* DHCP_ERR_MESSAGE   */
  48 //TODO: must be combined with 'sname' and 'file' handling:
  49         { OPTION_STRING                           , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
  50         { OPTION_STRING                           , 0x43 }, /* DHCP_BOOT_FILE     */
  51 //TODO: not a string, but a set of LASCII strings:
  52 //      { OPTION_STRING                           , 0x4D }, /* DHCP_USER_CLASS    */
  53 #if ENABLE_FEATURE_UDHCP_RFC3397
  54         { OPTION_DNS_STRING | OPTION_LIST         , 0x77 }, /* DHCP_DOMAIN_SEARCH */
  55         { OPTION_SIP_SERVERS                      , 0x78 }, /* DHCP_SIP_SERVERS   */
  56 #endif
  57         { OPTION_STATIC_ROUTES                    , 0x79 }, /* DHCP_STATIC_ROUTES */
  58         { OPTION_STATIC_ROUTES                    , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
  59         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
  60
  61         /* Options below have no match in dhcp_option_strings[],
  62          * are not passed to dhcpc scripts, and cannot be specified
  63          * with "option XXX YYY" syntax in dhcpd config file.
  64          * These entries are only used internally by udhcp[cd]
  65          * to correctly encode options into packets.
  66          */
  67
  68         { OPTION_IP                               , 0x32 }, /* DHCP_REQUESTED_IP  */
  69         { OPTION_U8                               , 0x35 }, /* DHCP_MESSAGE_TYPE  */
  70         { OPTION_U16                              , 0x39 }, /* DHCP_MAX_SIZE      */
  71         { OPTION_STRING                           , 0x3c }, /* DHCP_VENDOR        */
  72 //FIXME: handling of this option is not exactly correct:
  73         { OPTION_STRING                           , 0x3d }, /* DHCP_CLIENT_ID     */
  74         { 0, 0 } /* zeroed terminating entry */
  75 };
  76
  77 /* Used for converting options from incoming packets to env variables
  78  * for udhcpc stript, and for setting options for udhcpd via
  79  * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
  80  */
  81 /* Must match dhcp_optflags[] order */
  82 const char dhcp_option_strings[] ALIGN1 =
  83         "subnet" "\0"      /* DHCP_SUBNET         */
  84         "timezone" "\0"    /* DHCP_TIME_OFFSET    */
  85         "router" "\0"      /* DHCP_ROUTER         */
  86 //      "timesrv" "\0"     /* DHCP_TIME_SERVER    */
  87 //      "namesrv" "\0"     /* DHCP_NAME_SERVER    */
  88         "dns" "\0"         /* DHCP_DNS_SERVER     */
  89 //      "logsrv" "\0"      /* DHCP_LOG_SERVER     */
  90 //      "cookiesrv" "\0"   /* DHCP_COOKIE_SERVER  */
  91         "lprsrv" "\0"      /* DHCP_LPR_SERVER     */
  92         "hostname" "\0"    /* DHCP_HOST_NAME      */
  93         "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
  94         "domain" "\0"      /* DHCP_DOMAIN_NAME    */
  95         "swapsrv" "\0"     /* DHCP_SWAP_SERVER    */
  96         "rootpath" "\0"    /* DHCP_ROOT_PATH      */
  97         "ipttl" "\0"       /* DHCP_IP_TTL         */
  98         "mtu" "\0"         /* DHCP_MTU            */
  99         "broadcast" "\0"   /* DHCP_BROADCAST      */
 100         "routes" "\0"      /* DHCP_ROUTES         */
 101         "nisdomain" "\0"   /* DHCP_NIS_DOMAIN     */
 102         "nissrv" "\0"      /* DHCP_NIS_SERVER     */
 103         "ntpsrv" "\0"      /* DHCP_NTP_SERVER     */
 104         "wins" "\0"        /* DHCP_WINS_SERVER    */
 105         "lease" "\0"       /* DHCP_LEASE_TIME     */
 106         "serverid" "\0"    /* DHCP_SERVER_ID      */
 107         "message" "\0"     /* DHCP_ERR_MESSAGE    */
 108         "tftp" "\0"        /* DHCP_TFTP_SERVER_NAME */
 109         "bootfile" "\0"    /* DHCP_BOOT_FILE      */
 110 //      "userclass" "\0"   /* DHCP_USER_CLASS     */
 111 #if ENABLE_FEATURE_UDHCP_RFC3397
 112         "search" "\0"      /* DHCP_DOMAIN_SEARCH  */
 113 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
 114 // is not handled yet by "string->option" conversion code:
 115         "sipsrv" "\0"      /* DHCP_SIP_SERVERS    */
 116 #endif
 117 // doesn't work in udhcpd.conf since OPTION_STATIC_ROUTES
 118 // is not handled yet by "string->option" conversion code:
 119         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
 120         "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
 121         "wpad" "\0"        /* DHCP_WPAD           */
 122         ;
 123
 124 /* Lengths of the option types in binary form.
 125  * Used by:
 126  * udhcp_str2optset: to determine how many bytes to allocate.
 127  * xmalloc_optname_optval: to estimate string length
 128  * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
 129  * is the number of elements, multiply in by one element's string width
 130  * (len_of_option_as_string[opt_type]) and you know how wide string you need.
 131  */
 132 const uint8_t dhcp_option_lengths[] ALIGN1 = {
 133         [OPTION_IP] =      4,
 134         [OPTION_IP_PAIR] = 8,
 135 //      [OPTION_BOOLEAN] = 1,
 136         [OPTION_STRING] =  1,  /* ignored by udhcp_str2optset */
 137 #if ENABLE_FEATURE_UDHCP_RFC3397
 138         [OPTION_DNS_STRING] = 1,  /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
 139         [OPTION_SIP_SERVERS] = 1,
 140 #endif
 141         [OPTION_U8] =      1,
 142         [OPTION_U16] =     2,
 143 //      [OPTION_S16] =     2,
 144         [OPTION_U32] =     4,
 145         [OPTION_S32] =     4,
 146         /* Just like OPTION_STRING, we use minimum length here */
 147         [OPTION_STATIC_ROUTES] = 5,
 148 };
 149
 150
 151 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
 152 static void log_option(const char *pfx, const uint8_t *opt)
 153 {
 154         if (dhcp_verbose >= 2) {
 155                 char buf[256 * 2 + 2];
 156                 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
 157                 bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
 158         }
 159 }
 160 #else
 161 # define log_option(pfx, opt) ((void)0)
 162 #endif
 163
 164 unsigned FAST_FUNC udhcp_option_idx(const char *name)
 165 {
 166         int n = index_in_strings(dhcp_option_strings, name);
 167         if (n >= 0)
 168                 return n;
 169
 170         {
 171                 char buf[sizeof(dhcp_option_strings)];
 172                 char *d = buf;
 173                 const char *s = dhcp_option_strings;
 174                 while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
 175                         *d++ = (*s == '\0' ? ' ' : *s);
 176                         s++;
 177                 }
 178                 *d = '\0';
 179                 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
 180         }
 181 }
 182
 183 /* Get an option with bounds checking (warning, result is not aligned) */
 184 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
 185 {
 186         uint8_t *optionptr;
 187         int len;
 188         int rem;
 189         int overload = 0;
 190         enum {
 191                 FILE_FIELD101  = FILE_FIELD  * 0x101,
 192                 SNAME_FIELD101 = SNAME_FIELD * 0x101,
 193         };
 194
 195         /* option bytes: [code][len][data1][data2]..[dataLEN] */
 196         optionptr = packet->options;
 197         rem = sizeof(packet->options);
 198         while (1) {
 199                 if (rem <= 0) {
 200                         bb_error_msg("bad packet, malformed option field");
 201                         return NULL;
 202                 }
 203                 if (optionptr[OPT_CODE] == DHCP_PADDING) {
 204                         rem--;
 205                         optionptr++;
 206                         continue;
 207                 }
 208                 if (optionptr[OPT_CODE] == DHCP_END) {
 209                         if ((overload & FILE_FIELD101) == FILE_FIELD) {
 210                                 /* can use packet->file, and didn't look at it yet */
 211                                 overload |= FILE_FIELD101; /* "we looked at it" */
 212                                 optionptr = packet->file;
 213                                 rem = sizeof(packet->file);
 214                                 continue;
 215                         }
 216                         if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
 217                                 /* can use packet->sname, and didn't look at it yet */
 218                                 overload |= SNAME_FIELD101; /* "we looked at it" */
 219                                 optionptr = packet->sname;
 220                                 rem = sizeof(packet->sname);
 221                                 continue;
 222                         }
 223                         break;
 224                 }
 225                 len = 2 + optionptr[OPT_LEN];
 226                 rem -= len;
 227                 if (rem < 0)
 228                         continue; /* complain and return NULL */
 229
 230                 if (optionptr[OPT_CODE] == code) {
 231                         log_option("Option found", optionptr);
 232                         return optionptr + OPT_DATA;
 233                 }
 234
 235                 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
 236                         overload |= optionptr[OPT_DATA];
 237                         /* fall through */
 238                 }
 239                 optionptr += len;
 240         }
 241
 242         /* log3 because udhcpc uses it a lot - very noisy */
 243         log3("Option 0x%02x not found", code);
 244         return NULL;
 245 }
 246
 247 /* Return the position of the 'end' option (no bounds checking) */
 248 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 249 {
 250         int i = 0;
 251
 252         while (optionptr[i] != DHCP_END) {
 253                 if (optionptr[i] != DHCP_PADDING)
 254                         i += optionptr[i + OPT_LEN] + OPT_DATA-1;
 255                 i++;
 256         }
 257         return i;
 258 }
 259
 260 /* Add an option (supplied in binary form) to the options.
 261  * Option format: [code][len][data1][data2]..[dataLEN]
 262  */
 263 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 264 {
 265         unsigned len;
 266         uint8_t *optionptr = packet->options;
 267         unsigned end = udhcp_end_option(optionptr);
 268
 269         len = OPT_DATA + addopt[OPT_LEN];
 270         /* end position + (option code/length + addopt length) + end option */
 271         if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
 272 //TODO: learn how to use overflow option if we exhaust packet->options[]
 273                 bb_error_msg("option 0x%02x did not fit into the packet",
 274                                 addopt[OPT_CODE]);
 275                 return;
 276         }
 277         log_option("Adding option", addopt);
 278         memcpy(optionptr + end, addopt, len);
 279         optionptr[end + len] = DHCP_END;
 280 }
 281
 282 /* Add an one to four byte option to a packet */
 283 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
 284 {
 285         const struct dhcp_optflag *dh;
 286
 287         for (dh = dhcp_optflags; dh->code; dh++) {
 288                 if (dh->code == code) {
 289                         uint8_t option[6], len;
 290
 291                         option[OPT_CODE] = code;
 292                         len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
 293                         option[OPT_LEN] = len;
 294                         if (BB_BIG_ENDIAN)
 295                                 data <<= 8 * (4 - len);
 296                         /* Assignment is unaligned! */
 297                         move_to_unaligned32(&option[OPT_DATA], data);
 298                         udhcp_add_binary_option(packet, option);
 299                         return;
 300                 }
 301         }
 302
 303         bb_error_msg("can't add option 0x%02x", code);
 304 }
 305
 306 /* Find option 'code' in opt_list */
 307 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
 308 {
 309         while (opt_list && opt_list->data[OPT_CODE] < code)
 310                 opt_list = opt_list->next;
 311
 312         if (opt_list && opt_list->data[OPT_CODE] == code)
 313                 return opt_list;
 314         return NULL;
 315 }
 316
 317 /* Parse string to IP in network order */
 318 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
 319 {
 320         len_and_sockaddr *lsa;
 321
 322         lsa = host_and_af2sockaddr(str, 0, AF_INET);
 323         if (!lsa)
 324                 return 0;
 325         *(uint32_t*)arg = lsa->u.sin.sin_addr.s_addr;
 326         free(lsa);
 327         return 1;
 328 }
 329
 330 /* udhcp_str2optset:
 331  * Parse string option representation to binary form and add it to opt_list.
 332  * Called to parse "udhcpc -x OPTNAME:OPTVAL"
 333  * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
 334  */
 335 /* helper for the helper */
 336 static char *allocate_tempopt_if_needed(
 337                 const struct dhcp_optflag *optflag,
 338                 char *buffer,
 339                 int *length_p)
 340 {
 341         char *allocated = NULL;
 342         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
 343                 const char *end;
 344                 allocated = xstrdup(buffer); /* more than enough */
 345                 end = hex2bin(allocated, buffer, 255);
 346                 if (errno)
 347                         bb_error_msg_and_die("malformed hex string '%s'", buffer);
 348                 *length_p = end - allocated;
 349         }
 350         return allocated;
 351 }
 352 /* helper: add an option to the opt_list */
 353 static NOINLINE void attach_option(
 354                 struct option_set **opt_list,
 355                 const struct dhcp_optflag *optflag,
 356                 char *buffer,
 357                 int length)
 358 {
 359         struct option_set *existing, *new, **curr;
 360         char *allocated = NULL;
 361
 362         existing = udhcp_find_option(*opt_list, optflag->code);
 363         if (!existing) {
 364                 log2("Attaching option %02x to list", optflag->code);
 365                 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 366 #if ENABLE_FEATURE_UDHCP_RFC3397
 367                 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 368                         /* reuse buffer and length for RFC1035-formatted string */
 369                         allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
 370                 }
 371 #endif
 372                 /* make a new option */
 373                 new = xmalloc(sizeof(*new));
 374                 new->data = xmalloc(length + OPT_DATA);
 375                 new->data[OPT_CODE] = optflag->code;
 376                 new->data[OPT_LEN] = length;
 377                 memcpy(new->data + OPT_DATA, buffer, length);
 378
 379                 curr = opt_list;
 380                 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
 381                         curr = &(*curr)->next;
 382
 383                 new->next = *curr;
 384                 *curr = new;
 385                 goto ret;
 386         }
 387
 388         if (optflag->flags & OPTION_LIST) {
 389                 unsigned old_len;
 390
 391                 /* add it to an existing option */
 392                 log2("Attaching option %02x to existing member of list", optflag->code);
 393                 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 394                 old_len = existing->data[OPT_LEN];
 395 #if ENABLE_FEATURE_UDHCP_RFC3397
 396                 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 397                         /* reuse buffer and length for RFC1035-formatted string */
 398                         allocated = buffer = (char *)dname_enc(existing->data + OPT_DATA, old_len, buffer, &length);
 399                 }
 400 #endif
 401                 if (old_len + length < 255) {
 402                         /* actually 255 is ok too, but adding a space can overlow it */
 403
 404                         existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
 405                         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING) {
 406                                 /* add space separator between STRING options in a list */
 407                                 existing->data[OPT_DATA + old_len] = ' ';
 408                                 old_len++;
 409                         }
 410                         memcpy(existing->data + OPT_DATA + old_len, buffer, length);
 411                         existing->data[OPT_LEN] = old_len + length;
 412                 } /* else, ignore the data, we could put this in a second option in the future */
 413         } /* else, ignore the new data */
 414
 415  ret:
 416         free(allocated);
 417 }
 418
 419 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
 420 {
 421         struct option_set **opt_list = arg;
 422         char *opt, *val, *endptr;
 423         char *str;
 424         const struct dhcp_optflag *optflag;
 425         struct dhcp_optflag bin_optflag;
 426         unsigned optcode;
 427         int retval, length;
 428         char buffer[8] ALIGNED(4);
 429         uint16_t *result_u16 = (uint16_t *) buffer;
 430         uint32_t *result_u32 = (uint32_t *) buffer;
 431
 432         /* Cheat, the only *const* str possible is "" */
 433         str = (char *) const_str;
 434         opt = strtok(str, " \t=");
 435         if (!opt)
 436                 return 0;
 437
 438         optcode = bb_strtou(opt, NULL, 0);
 439         if (!errno && optcode < 255) {
 440                 /* Raw (numeric) option code */
 441                 bin_optflag.flags = OPTION_BIN;
 442                 bin_optflag.code = optcode;
 443                 optflag = &bin_optflag;
 444         } else {
 445                 optflag = &dhcp_optflags[udhcp_option_idx(opt)];
 446         }
 447
 448         retval = 0;
 449         do {
 450                 val = strtok(NULL, ", \t");
 451                 if (!val)
 452                         break;
 453                 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
 454                 retval = 0;
 455                 opt = buffer; /* new meaning for variable opt */
 456                 switch (optflag->flags & OPTION_TYPE_MASK) {
 457                 case OPTION_IP:
 458                         retval = udhcp_str2nip(val, buffer);
 459                         break;
 460                 case OPTION_IP_PAIR:
 461                         retval = udhcp_str2nip(val, buffer);
 462                         val = strtok(NULL, ", \t/-");
 463                         if (!val)
 464                                 retval = 0;
 465                         if (retval)
 466                                 retval = udhcp_str2nip(val, buffer + 4);
 467                         break;
 468                 case OPTION_STRING:
 469 #if ENABLE_FEATURE_UDHCP_RFC3397
 470                 case OPTION_DNS_STRING:
 471 #endif
 472                         length = strnlen(val, 254);
 473                         if (length > 0) {
 474                                 opt = val;
 475                                 retval = 1;
 476                         }
 477                         break;
 478 //              case OPTION_BOOLEAN: {
 479 //                      static const char no_yes[] ALIGN1 = "no\0yes\0";
 480 //                      buffer[0] = retval = index_in_strings(no_yes, val);
 481 //                      retval++; /* 0 - bad; 1: "no" 2: "yes" */
 482 //                      break;
 483 //              }
 484                 case OPTION_U8:
 485                         buffer[0] = strtoul(val, &endptr, 0);
 486                         retval = (endptr[0] == '\0');
 487                         break;
 488                 /* htonX are macros in older libc's, using temp var
 489                  * in code below for safety */
 490                 /* TODO: use bb_strtoX? */
 491                 case OPTION_U16: {
 492                         unsigned long tmp = strtoul(val, &endptr, 0);
 493                         *result_u16 = htons(tmp);
 494                         retval = (endptr[0] == '\0' /*&& tmp < 0x10000*/);
 495                         break;
 496                 }
 497 //              case OPTION_S16: {
 498 //                      long tmp = strtol(val, &endptr, 0);
 499 //                      *result_u16 = htons(tmp);
 500 //                      retval = (endptr[0] == '\0');
 501 //                      break;
 502 //              }
 503                 case OPTION_U32: {
 504                         unsigned long tmp = strtoul(val, &endptr, 0);
 505                         *result_u32 = htonl(tmp);
 506                         retval = (endptr[0] == '\0');
 507                         break;
 508                 }
 509                 case OPTION_S32: {
 510                         long tmp = strtol(val, &endptr, 0);
 511                         *result_u32 = htonl(tmp);
 512                         retval = (endptr[0] == '\0');
 513                         break;
 514                 }
 515                 case OPTION_BIN: /* handled in attach_option() */
 516                         opt = val;
 517                         retval = 1;
 518                 default:
 519                         break;
 520                 }
 521                 if (retval)
 522                         attach_option(opt_list, optflag, opt, length);
 523         } while (retval && optflag->flags & OPTION_LIST);
 524
 525         return retval;
 526 }