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 //looks like these opts will work just fine even without these defs:
  72 //      { OPTION_STRING                           , 0x3c }, /* DHCP_VENDOR        */
  73 //      /* not really a string: */
  74 //      { OPTION_STRING                           , 0x3d }, /* DHCP_CLIENT_ID     */
  75         { 0, 0 } /* zeroed terminating entry */
  76 };
  77
  78 /* Used for converting options from incoming packets to env variables
  79  * for udhcpc stript, and for setting options for udhcpd via
  80  * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
  81  */
  82 /* Must match dhcp_optflags[] order */
  83 const char dhcp_option_strings[] ALIGN1 =
  84         "subnet" "\0"      /* DHCP_SUBNET         */
  85         "timezone" "\0"    /* DHCP_TIME_OFFSET    */
  86         "router" "\0"      /* DHCP_ROUTER         */
  87 //      "timesrv" "\0"     /* DHCP_TIME_SERVER    */
  88 //      "namesrv" "\0"     /* DHCP_NAME_SERVER    */
  89         "dns" "\0"         /* DHCP_DNS_SERVER     */
  90 //      "logsrv" "\0"      /* DHCP_LOG_SERVER     */
  91 //      "cookiesrv" "\0"   /* DHCP_COOKIE_SERVER  */
  92         "lprsrv" "\0"      /* DHCP_LPR_SERVER     */
  93         "hostname" "\0"    /* DHCP_HOST_NAME      */
  94         "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
  95         "domain" "\0"      /* DHCP_DOMAIN_NAME    */
  96         "swapsrv" "\0"     /* DHCP_SWAP_SERVER    */
  97         "rootpath" "\0"    /* DHCP_ROOT_PATH      */
  98         "ipttl" "\0"       /* DHCP_IP_TTL         */
  99         "mtu" "\0"         /* DHCP_MTU            */
 100         "broadcast" "\0"   /* DHCP_BROADCAST      */
 101         "routes" "\0"      /* DHCP_ROUTES         */
 102         "nisdomain" "\0"   /* DHCP_NIS_DOMAIN     */
 103         "nissrv" "\0"      /* DHCP_NIS_SERVER     */
 104         "ntpsrv" "\0"      /* DHCP_NTP_SERVER     */
 105         "wins" "\0"        /* DHCP_WINS_SERVER    */
 106         "lease" "\0"       /* DHCP_LEASE_TIME     */
 107         "serverid" "\0"    /* DHCP_SERVER_ID      */
 108         "message" "\0"     /* DHCP_ERR_MESSAGE    */
 109         "tftp" "\0"        /* DHCP_TFTP_SERVER_NAME */
 110         "bootfile" "\0"    /* DHCP_BOOT_FILE      */
 111 //      "userclass" "\0"   /* DHCP_USER_CLASS     */
 112 #if ENABLE_FEATURE_UDHCP_RFC3397
 113         "search" "\0"      /* DHCP_DOMAIN_SEARCH  */
 114 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
 115 // is not handled yet by "string->option" conversion code:
 116         "sipsrv" "\0"      /* DHCP_SIP_SERVERS    */
 117 #endif
 118 // doesn't work in udhcpd.conf since OPTION_STATIC_ROUTES
 119 // is not handled yet by "string->option" conversion code:
 120         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
 121         "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
 122         "wpad" "\0"        /* DHCP_WPAD           */
 123         ;
 124
 125 /* Lengths of the option types in binary form.
 126  * Used by:
 127  * udhcp_str2optset: to determine how many bytes to allocate.
 128  * xmalloc_optname_optval: to estimate string length
 129  * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
 130  * is the number of elements, multiply in by one element's string width
 131  * (len_of_option_as_string[opt_type]) and you know how wide string you need.
 132  */
 133 const uint8_t dhcp_option_lengths[] ALIGN1 = {
 134         [OPTION_IP] =      4,
 135         [OPTION_IP_PAIR] = 8,
 136 //      [OPTION_BOOLEAN] = 1,
 137         [OPTION_STRING] =  1,  /* ignored by udhcp_str2optset */
 138 #if ENABLE_FEATURE_UDHCP_RFC3397
 139         [OPTION_DNS_STRING] = 1,  /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
 140         [OPTION_SIP_SERVERS] = 1,
 141 #endif
 142         [OPTION_U8] =      1,
 143         [OPTION_U16] =     2,
 144 //      [OPTION_S16] =     2,
 145         [OPTION_U32] =     4,
 146         [OPTION_S32] =     4,
 147         /* Just like OPTION_STRING, we use minimum length here */
 148         [OPTION_STATIC_ROUTES] = 5,
 149 };
 150
 151
 152 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
 153 static void log_option(const char *pfx, const uint8_t *opt)
 154 {
 155         if (dhcp_verbose >= 2) {
 156                 char buf[256 * 2 + 2];
 157                 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
 158                 bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
 159         }
 160 }
 161 #else
 162 # define log_option(pfx, opt) ((void)0)
 163 #endif
 164
 165 unsigned FAST_FUNC udhcp_option_idx(const char *name)
 166 {
 167         int n = index_in_strings(dhcp_option_strings, name);
 168         if (n >= 0)
 169                 return n;
 170
 171         {
 172                 char buf[sizeof(dhcp_option_strings)];
 173                 char *d = buf;
 174                 const char *s = dhcp_option_strings;
 175                 while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
 176                         *d++ = (*s == '\0' ? ' ' : *s);
 177                         s++;
 178                 }
 179                 *d = '\0';
 180                 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
 181         }
 182 }
 183
 184 /* Get an option with bounds checking (warning, result is not aligned) */
 185 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
 186 {
 187         uint8_t *optionptr;
 188         int len;
 189         int rem;
 190         int overload = 0;
 191         enum {
 192                 FILE_FIELD101  = FILE_FIELD  * 0x101,
 193                 SNAME_FIELD101 = SNAME_FIELD * 0x101,
 194         };
 195
 196         /* option bytes: [code][len][data1][data2]..[dataLEN] */
 197         optionptr = packet->options;
 198         rem = sizeof(packet->options);
 199         while (1) {
 200                 if (rem <= 0) {
 201                         bb_error_msg("bad packet, malformed option field");
 202                         return NULL;
 203                 }
 204                 if (optionptr[OPT_CODE] == DHCP_PADDING) {
 205                         rem--;
 206                         optionptr++;
 207                         continue;
 208                 }
 209                 if (optionptr[OPT_CODE] == DHCP_END) {
 210                         if ((overload & FILE_FIELD101) == FILE_FIELD) {
 211                                 /* can use packet->file, and didn't look at it yet */
 212                                 overload |= FILE_FIELD101; /* "we looked at it" */
 213                                 optionptr = packet->file;
 214                                 rem = sizeof(packet->file);
 215                                 continue;
 216                         }
 217                         if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
 218                                 /* can use packet->sname, and didn't look at it yet */
 219                                 overload |= SNAME_FIELD101; /* "we looked at it" */
 220                                 optionptr = packet->sname;
 221                                 rem = sizeof(packet->sname);
 222                                 continue;
 223                         }
 224                         break;
 225                 }
 226                 len = 2 + optionptr[OPT_LEN];
 227                 rem -= len;
 228                 if (rem < 0)
 229                         continue; /* complain and return NULL */
 230
 231                 if (optionptr[OPT_CODE] == code) {
 232                         log_option("Option found", optionptr);
 233                         return optionptr + OPT_DATA;
 234                 }
 235
 236                 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
 237                         overload |= optionptr[OPT_DATA];
 238                         /* fall through */
 239                 }
 240                 optionptr += len;
 241         }
 242
 243         /* log3 because udhcpc uses it a lot - very noisy */
 244         log3("Option 0x%02x not found", code);
 245         return NULL;
 246 }
 247
 248 /* Return the position of the 'end' option (no bounds checking) */
 249 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 250 {
 251         int i = 0;
 252
 253         while (optionptr[i] != DHCP_END) {
 254                 if (optionptr[i] != DHCP_PADDING)
 255                         i += optionptr[i + OPT_LEN] + OPT_DATA-1;
 256                 i++;
 257         }
 258         return i;
 259 }
 260
 261 /* Add an option (supplied in binary form) to the options.
 262  * Option format: [code][len][data1][data2]..[dataLEN]
 263  */
 264 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 265 {
 266         unsigned len;
 267         uint8_t *optionptr = packet->options;
 268         unsigned end = udhcp_end_option(optionptr);
 269
 270         len = OPT_DATA + addopt[OPT_LEN];
 271         /* end position + (option code/length + addopt length) + end option */
 272         if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
 273 //TODO: learn how to use overflow option if we exhaust packet->options[]
 274                 bb_error_msg("option 0x%02x did not fit into the packet",
 275                                 addopt[OPT_CODE]);
 276                 return;
 277         }
 278         log_option("Adding option", addopt);
 279         memcpy(optionptr + end, addopt, len);
 280         optionptr[end + len] = DHCP_END;
 281 }
 282
 283 /* Add an one to four byte option to a packet */
 284 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
 285 {
 286         const struct dhcp_optflag *dh;
 287
 288         for (dh = dhcp_optflags; dh->code; dh++) {
 289                 if (dh->code == code) {
 290                         uint8_t option[6], len;
 291
 292                         option[OPT_CODE] = code;
 293                         len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
 294                         option[OPT_LEN] = len;
 295                         if (BB_BIG_ENDIAN)
 296                                 data <<= 8 * (4 - len);
 297                         /* Assignment is unaligned! */
 298                         move_to_unaligned32(&option[OPT_DATA], data);
 299                         udhcp_add_binary_option(packet, option);
 300                         return;
 301                 }
 302         }
 303
 304         bb_error_msg("can't add option 0x%02x", code);
 305 }
 306
 307 /* Find option 'code' in opt_list */
 308 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
 309 {
 310         while (opt_list && opt_list->data[OPT_CODE] < code)
 311                 opt_list = opt_list->next;
 312
 313         if (opt_list && opt_list->data[OPT_CODE] == code)
 314                 return opt_list;
 315         return NULL;
 316 }
 317
 318 /* Parse string to IP in network order */
 319 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
 320 {
 321         len_and_sockaddr *lsa;
 322
 323         lsa = host_and_af2sockaddr(str, 0, AF_INET);
 324         if (!lsa)
 325                 return 0;
 326         *(uint32_t*)arg = lsa->u.sin.sin_addr.s_addr;
 327         free(lsa);
 328         return 1;
 329 }
 330
 331 /* udhcp_str2optset:
 332  * Parse string option representation to binary form and add it to opt_list.
 333  * Called to parse "udhcpc -x OPTNAME:OPTVAL"
 334  * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
 335  */
 336 /* helper for the helper */
 337 static char *allocate_tempopt_if_needed(
 338                 const struct dhcp_optflag *optflag,
 339                 char *buffer,
 340                 int *length_p)
 341 {
 342         char *allocated = NULL;
 343         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
 344                 const char *end;
 345                 allocated = xstrdup(buffer); /* more than enough */
 346                 end = hex2bin(allocated, buffer, 255);
 347                 if (errno)
 348                         bb_error_msg_and_die("malformed hex string '%s'", buffer);
 349                 *length_p = end - allocated;
 350         }
 351         return allocated;
 352 }
 353 /* helper: add an option to the opt_list */
 354 static NOINLINE void attach_option(
 355                 struct option_set **opt_list,
 356                 const struct dhcp_optflag *optflag,
 357                 char *buffer,
 358                 int length)
 359 {
 360         struct option_set *existing, *new, **curr;
 361         char *allocated = NULL;
 362
 363         existing = udhcp_find_option(*opt_list, optflag->code);
 364         if (!existing) {
 365                 log2("Attaching option %02x to list", optflag->code);
 366                 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 367 #if ENABLE_FEATURE_UDHCP_RFC3397
 368                 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 369                         /* reuse buffer and length for RFC1035-formatted string */
 370                         allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
 371                 }
 372 #endif
 373                 /* make a new option */
 374                 new = xmalloc(sizeof(*new));
 375                 new->data = xmalloc(length + OPT_DATA);
 376                 new->data[OPT_CODE] = optflag->code;
 377                 new->data[OPT_LEN] = length;
 378                 memcpy(new->data + OPT_DATA, buffer, length);
 379
 380                 curr = opt_list;
 381                 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
 382                         curr = &(*curr)->next;
 383
 384                 new->next = *curr;
 385                 *curr = new;
 386                 goto ret;
 387         }
 388
 389         if (optflag->flags & OPTION_LIST) {
 390                 unsigned old_len;
 391
 392                 /* add it to an existing option */
 393                 log2("Attaching option %02x to existing member of list", optflag->code);
 394                 allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 395                 old_len = existing->data[OPT_LEN];
 396 #if ENABLE_FEATURE_UDHCP_RFC3397
 397                 if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 398                         /* reuse buffer and length for RFC1035-formatted string */
 399                         allocated = buffer = (char *)dname_enc(existing->data + OPT_DATA, old_len, buffer, &length);
 400                 }
 401 #endif
 402                 if (old_len + length < 255) {
 403                         /* actually 255 is ok too, but adding a space can overlow it */
 404
 405                         existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
 406                         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING) {
 407                                 /* add space separator between STRING options in a list */
 408                                 existing->data[OPT_DATA + old_len] = ' ';
 409                                 old_len++;
 410                         }
 411                         memcpy(existing->data + OPT_DATA + old_len, buffer, length);
 412                         existing->data[OPT_LEN] = old_len + length;
 413                 } /* else, ignore the data, we could put this in a second option in the future */
 414         } /* else, ignore the new data */
 415
 416  ret:
 417         free(allocated);
 418 }
 419
 420 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
 421 {
 422         struct option_set **opt_list = arg;
 423         char *opt, *val, *endptr;
 424         char *str;
 425         const struct dhcp_optflag *optflag;
 426         struct dhcp_optflag bin_optflag;
 427         unsigned optcode;
 428         int retval, length;
 429         char buffer[8] ALIGNED(4);
 430         uint16_t *result_u16 = (uint16_t *) buffer;
 431         uint32_t *result_u32 = (uint32_t *) buffer;
 432
 433         /* Cheat, the only *const* str possible is "" */
 434         str = (char *) const_str;
 435         opt = strtok(str, " \t=");
 436         if (!opt)
 437                 return 0;
 438
 439         optcode = bb_strtou(opt, NULL, 0);
 440         if (!errno && optcode < 255) {
 441                 /* Raw (numeric) option code */
 442                 bin_optflag.flags = OPTION_BIN;
 443                 bin_optflag.code = optcode;
 444                 optflag = &bin_optflag;
 445         } else {
 446                 optflag = &dhcp_optflags[udhcp_option_idx(opt)];
 447         }
 448
 449         retval = 0;
 450         do {
 451                 val = strtok(NULL, ", \t");
 452                 if (!val)
 453                         break;
 454                 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
 455                 retval = 0;
 456                 opt = buffer; /* new meaning for variable opt */
 457                 switch (optflag->flags & OPTION_TYPE_MASK) {
 458                 case OPTION_IP:
 459                         retval = udhcp_str2nip(val, buffer);
 460                         break;
 461                 case OPTION_IP_PAIR:
 462                         retval = udhcp_str2nip(val, buffer);
 463                         val = strtok(NULL, ", \t/-");
 464                         if (!val)
 465                                 retval = 0;
 466                         if (retval)
 467                                 retval = udhcp_str2nip(val, buffer + 4);
 468                         break;
 469                 case OPTION_STRING:
 470 #if ENABLE_FEATURE_UDHCP_RFC3397
 471                 case OPTION_DNS_STRING:
 472 #endif
 473                         length = strnlen(val, 254);
 474                         if (length > 0) {
 475                                 opt = val;
 476                                 retval = 1;
 477                         }
 478                         break;
 479 //              case OPTION_BOOLEAN: {
 480 //                      static const char no_yes[] ALIGN1 = "no\0yes\0";
 481 //                      buffer[0] = retval = index_in_strings(no_yes, val);
 482 //                      retval++; /* 0 - bad; 1: "no" 2: "yes" */
 483 //                      break;
 484 //              }
 485                 case OPTION_U8:
 486                         buffer[0] = strtoul(val, &endptr, 0);
 487                         retval = (endptr[0] == '\0');
 488                         break;
 489                 /* htonX are macros in older libc's, using temp var
 490                  * in code below for safety */
 491                 /* TODO: use bb_strtoX? */
 492                 case OPTION_U16: {
 493                         unsigned long tmp = strtoul(val, &endptr, 0);
 494                         *result_u16 = htons(tmp);
 495                         retval = (endptr[0] == '\0' /*&& tmp < 0x10000*/);
 496                         break;
 497                 }
 498 //              case OPTION_S16: {
 499 //                      long tmp = strtol(val, &endptr, 0);
 500 //                      *result_u16 = htons(tmp);
 501 //                      retval = (endptr[0] == '\0');
 502 //                      break;
 503 //              }
 504                 case OPTION_U32: {
 505                         unsigned long tmp = strtoul(val, &endptr, 0);
 506                         *result_u32 = htonl(tmp);
 507                         retval = (endptr[0] == '\0');
 508                         break;
 509                 }
 510                 case OPTION_S32: {
 511                         long tmp = strtol(val, &endptr, 0);
 512                         *result_u32 = htonl(tmp);
 513                         retval = (endptr[0] == '\0');
 514                         break;
 515                 }
 516                 case OPTION_BIN: /* handled in attach_option() */
 517                         opt = val;
 518                         retval = 1;
 519                 default:
 520                         break;
 521                 }
 522                 if (retval)
 523                         attach_option(opt_list, optflag, opt, length);
 524         } while (retval && optflag->flags & OPTION_LIST);
 525
 526         return retval;
 527 }