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_HOST          | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME     */
  33         { OPTION_U16                              , 0x0d }, /* DHCP_BOOT_SIZE     */
  34         { OPTION_STRING_HOST          | 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 //TODO: why do we request DHCP_BROADCAST? Can't we assume that
  40 //in the unlikely case it is different from typical N.N.255.255,
  41 //server would let us know anyway?
  42         { OPTION_IP                   | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST     */
  43         { OPTION_IP_PAIR | OPTION_LIST            , 0x21 }, /* DHCP_ROUTES        */
  44         { OPTION_STRING_HOST                      , 0x28 }, /* DHCP_NIS_DOMAIN    */
  45         { OPTION_IP | OPTION_LIST                 , 0x29 }, /* DHCP_NIS_SERVER    */
  46         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER    */
  47         { OPTION_IP | OPTION_LIST                 , 0x2c }, /* DHCP_WINS_SERVER   */
  48         { OPTION_U32                              , 0x33 }, /* DHCP_LEASE_TIME    */
  49         { OPTION_IP                               , 0x36 }, /* DHCP_SERVER_ID     */
  50         { OPTION_STRING                           , 0x38 }, /* DHCP_ERR_MESSAGE   */
  51 //TODO: must be combined with 'sname' and 'file' handling:
  52         { OPTION_STRING_HOST                      , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
  53         { OPTION_STRING                           , 0x43 }, /* DHCP_BOOT_FILE     */
  54 //TODO: not a string, but a set of LASCII strings:
  55 //      { OPTION_STRING                           , 0x4D }, /* DHCP_USER_CLASS    */
  56 #if ENABLE_FEATURE_UDHCP_RFC3397
  57         { OPTION_DNS_STRING | OPTION_LIST         , 0x77 }, /* DHCP_DOMAIN_SEARCH */
  58         { OPTION_SIP_SERVERS                      , 0x78 }, /* DHCP_SIP_SERVERS   */
  59 #endif
  60         { OPTION_STATIC_ROUTES | OPTION_LIST      , 0x79 }, /* DHCP_STATIC_ROUTES */
  61 #if ENABLE_FEATURE_UDHCP_8021Q
  62         { OPTION_U16                              , 0x84 }, /* DHCP_VLAN_ID       */
  63         { OPTION_U8                               , 0x85 }, /* DHCP_VLAN_PRIORITY */
  64 #endif
  65         { OPTION_STRING                           , 0xd1 }, /* DHCP_PXE_CONF_FILE */
  66         { OPTION_6RD                              , 0xd4 }, /* DHCP_6RD           */
  67         { OPTION_STATIC_ROUTES | OPTION_LIST      , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
  68         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
  69
  70         /* Options below have no match in dhcp_option_strings[],
  71          * are not passed to dhcpc scripts, and cannot be specified
  72          * with "option XXX YYY" syntax in dhcpd config file.
  73          * These entries are only used internally by udhcp[cd]
  74          * to correctly encode options into packets.
  75          */
  76
  77         { OPTION_IP                               , 0x32 }, /* DHCP_REQUESTED_IP  */
  78         { OPTION_U8                               , 0x35 }, /* DHCP_MESSAGE_TYPE  */
  79         { OPTION_U16                              , 0x39 }, /* DHCP_MAX_SIZE      */
  80 //looks like these opts will work just fine even without these defs:
  81 //      { OPTION_STRING                           , 0x3c }, /* DHCP_VENDOR        */
  82 //      /* not really a string: */
  83 //      { OPTION_STRING                           , 0x3d }, /* DHCP_CLIENT_ID     */
  84         { 0, 0 } /* zeroed terminating entry */
  85 };
  86
  87 /* Used for converting options from incoming packets to env variables
  88  * for udhcpc stript, and for setting options for udhcpd via
  89  * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
  90  */
  91 /* Must match dhcp_optflags[] order */
  92 const char dhcp_option_strings[] ALIGN1 =
  93         "subnet" "\0"      /* DHCP_SUBNET         */
  94         "timezone" "\0"    /* DHCP_TIME_OFFSET    */
  95         "router" "\0"      /* DHCP_ROUTER         */
  96 //      "timesrv" "\0"     /* DHCP_TIME_SERVER    */
  97 //      "namesrv" "\0"     /* DHCP_NAME_SERVER    */
  98         "dns" "\0"         /* DHCP_DNS_SERVER     */
  99 //      "logsrv" "\0"      /* DHCP_LOG_SERVER     */
 100 //      "cookiesrv" "\0"   /* DHCP_COOKIE_SERVER  */
 101         "lprsrv" "\0"      /* DHCP_LPR_SERVER     */
 102         "hostname" "\0"    /* DHCP_HOST_NAME      */
 103         "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
 104         "domain" "\0"      /* DHCP_DOMAIN_NAME    */
 105         "swapsrv" "\0"     /* DHCP_SWAP_SERVER    */
 106         "rootpath" "\0"    /* DHCP_ROOT_PATH      */
 107         "ipttl" "\0"       /* DHCP_IP_TTL         */
 108         "mtu" "\0"         /* DHCP_MTU            */
 109         "broadcast" "\0"   /* DHCP_BROADCAST      */
 110         "routes" "\0"      /* DHCP_ROUTES         */
 111         "nisdomain" "\0"   /* DHCP_NIS_DOMAIN     */
 112         "nissrv" "\0"      /* DHCP_NIS_SERVER     */
 113         "ntpsrv" "\0"      /* DHCP_NTP_SERVER     */
 114         "wins" "\0"        /* DHCP_WINS_SERVER    */
 115         "lease" "\0"       /* DHCP_LEASE_TIME     */
 116         "serverid" "\0"    /* DHCP_SERVER_ID      */
 117         "message" "\0"     /* DHCP_ERR_MESSAGE    */
 118         "tftp" "\0"        /* DHCP_TFTP_SERVER_NAME */
 119         "bootfile" "\0"    /* DHCP_BOOT_FILE      */
 120 //      "userclass" "\0"   /* DHCP_USER_CLASS     */
 121 #if ENABLE_FEATURE_UDHCP_RFC3397
 122         "search" "\0"      /* DHCP_DOMAIN_SEARCH  */
 123 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
 124 // is not handled yet by "string->option" conversion code:
 125         "sipsrv" "\0"      /* DHCP_SIP_SERVERS    */
 126 #endif
 127         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
 128 #if ENABLE_FEATURE_UDHCP_8021Q
 129         "vlanid" "\0"      /* DHCP_VLAN_ID        */
 130         "vlanpriority" "\0"/* DHCP_VLAN_PRIORITY  */
 131 #endif
 132         "pxeconffile" "\0" /* DHCP_PXE_CONF_FILE  */
 133         "ip6rd" "\0"       /* DHCP_6RD            */
 134         "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
 135         "wpad" "\0"        /* DHCP_WPAD           */
 136         ;
 137
 138 /* Lengths of the option types in binary form.
 139  * Used by:
 140  * udhcp_str2optset: to determine how many bytes to allocate.
 141  * xmalloc_optname_optval: to estimate string length
 142  * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
 143  * is the number of elements, multiply in by one element's string width
 144  * (len_of_option_as_string[opt_type]) and you know how wide string you need.
 145  */
 146 const uint8_t dhcp_option_lengths[] ALIGN1 = {
 147         [OPTION_IP] =      4,
 148         [OPTION_IP_PAIR] = 8,
 149 //      [OPTION_BOOLEAN] = 1,
 150         [OPTION_STRING] =  1,  /* ignored by udhcp_str2optset */
 151         [OPTION_STRING_HOST] = 1,  /* ignored by udhcp_str2optset */
 152 #if ENABLE_FEATURE_UDHCP_RFC3397
 153         [OPTION_DNS_STRING] = 1,  /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
 154         [OPTION_SIP_SERVERS] = 1,
 155 #endif
 156         [OPTION_U8] =      1,
 157         [OPTION_U16] =     2,
 158 //      [OPTION_S16] =     2,
 159         [OPTION_U32] =     4,
 160         [OPTION_S32] =     4,
 161         /* Just like OPTION_STRING, we use minimum length here */
 162         [OPTION_STATIC_ROUTES] = 5,
 163         [OPTION_6RD] =    22,  /* ignored by udhcp_str2optset */
 164 };
 165
 166
 167 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
 168 static void log_option(const char *pfx, const uint8_t *opt)
 169 {
 170         if (dhcp_verbose >= 2) {
 171                 char buf[256 * 2 + 2];
 172                 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
 173                 bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
 174         }
 175 }
 176 #else
 177 # define log_option(pfx, opt) ((void)0)
 178 #endif
 179
 180 unsigned FAST_FUNC udhcp_option_idx(const char *name)
 181 {
 182         int n = index_in_strings(dhcp_option_strings, name);
 183         if (n >= 0)
 184                 return n;
 185
 186         {
 187                 char buf[sizeof(dhcp_option_strings)];
 188                 char *d = buf;
 189                 const char *s = dhcp_option_strings;
 190                 while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
 191                         *d++ = (*s == '\0' ? ' ' : *s);
 192                         s++;
 193                 }
 194                 *d = '\0';
 195                 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
 196         }
 197 }
 198
 199 /* Get an option with bounds checking (warning, result is not aligned) */
 200 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
 201 {
 202         uint8_t *optionptr;
 203         int len;
 204         int rem;
 205         int overload = 0;
 206         enum {
 207                 FILE_FIELD101  = FILE_FIELD  * 0x101,
 208                 SNAME_FIELD101 = SNAME_FIELD * 0x101,
 209         };
 210
 211         /* option bytes: [code][len][data1][data2]..[dataLEN] */
 212         optionptr = packet->options;
 213         rem = sizeof(packet->options);
 214         while (1) {
 215                 if (rem <= 0) {
 216                         bb_error_msg("bad packet, malformed option field");
 217                         return NULL;
 218                 }
 219                 if (optionptr[OPT_CODE] == DHCP_PADDING) {
 220                         rem--;
 221                         optionptr++;
 222                         continue;
 223                 }
 224                 if (optionptr[OPT_CODE] == DHCP_END) {
 225                         if ((overload & FILE_FIELD101) == FILE_FIELD) {
 226                                 /* can use packet->file, and didn't look at it yet */
 227                                 overload |= FILE_FIELD101; /* "we looked at it" */
 228                                 optionptr = packet->file;
 229                                 rem = sizeof(packet->file);
 230                                 continue;
 231                         }
 232                         if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
 233                                 /* can use packet->sname, and didn't look at it yet */
 234                                 overload |= SNAME_FIELD101; /* "we looked at it" */
 235                                 optionptr = packet->sname;
 236                                 rem = sizeof(packet->sname);
 237                                 continue;
 238                         }
 239                         break;
 240                 }
 241                 len = 2 + optionptr[OPT_LEN];
 242                 rem -= len;
 243                 if (rem < 0)
 244                         continue; /* complain and return NULL */
 245
 246                 if (optionptr[OPT_CODE] == code) {
 247                         log_option("Option found", optionptr);
 248                         return optionptr + OPT_DATA;
 249                 }
 250
 251                 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
 252                         overload |= optionptr[OPT_DATA];
 253                         /* fall through */
 254                 }
 255                 optionptr += len;
 256         }
 257
 258         /* log3 because udhcpc uses it a lot - very noisy */
 259         log3("Option 0x%02x not found", code);
 260         return NULL;
 261 }
 262
 263 /* Return the position of the 'end' option (no bounds checking) */
 264 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 265 {
 266         int i = 0;
 267
 268         while (optionptr[i] != DHCP_END) {
 269                 if (optionptr[i] != DHCP_PADDING)
 270                         i += optionptr[i + OPT_LEN] + OPT_DATA-1;
 271                 i++;
 272         }
 273         return i;
 274 }
 275
 276 /* Add an option (supplied in binary form) to the options.
 277  * Option format: [code][len][data1][data2]..[dataLEN]
 278  */
 279 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 280 {
 281         unsigned len;
 282         uint8_t *optionptr = packet->options;
 283         unsigned end = udhcp_end_option(optionptr);
 284
 285         len = OPT_DATA + addopt[OPT_LEN];
 286         /* end position + (option code/length + addopt length) + end option */
 287         if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
 288 //TODO: learn how to use overflow option if we exhaust packet->options[]
 289                 bb_error_msg("option 0x%02x did not fit into the packet",
 290                                 addopt[OPT_CODE]);
 291                 return;
 292         }
 293         log_option("Adding option", addopt);
 294         memcpy(optionptr + end, addopt, len);
 295         optionptr[end + len] = DHCP_END;
 296 }
 297
 298 /* Add an one to four byte option to a packet */
 299 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
 300 {
 301         const struct dhcp_optflag *dh;
 302
 303         for (dh = dhcp_optflags; dh->code; dh++) {
 304                 if (dh->code == code) {
 305                         uint8_t option[6], len;
 306
 307                         option[OPT_CODE] = code;
 308                         len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
 309                         option[OPT_LEN] = len;
 310                         if (BB_BIG_ENDIAN)
 311                                 data <<= 8 * (4 - len);
 312                         /* Assignment is unaligned! */
 313                         move_to_unaligned32(&option[OPT_DATA], data);
 314                         udhcp_add_binary_option(packet, option);
 315                         return;
 316                 }
 317         }
 318
 319         bb_error_msg("can't add option 0x%02x", code);
 320 }
 321
 322 /* Find option 'code' in opt_list */
 323 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
 324 {
 325         while (opt_list && opt_list->data[OPT_CODE] < code)
 326                 opt_list = opt_list->next;
 327
 328         if (opt_list && opt_list->data[OPT_CODE] == code)
 329                 return opt_list;
 330         return NULL;
 331 }
 332
 333 /* Parse string to IP in network order */
 334 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
 335 {
 336         len_and_sockaddr *lsa;
 337
 338         lsa = host_and_af2sockaddr(str, 0, AF_INET);
 339         if (!lsa)
 340                 return 0;
 341         /* arg maybe unaligned */
 342         move_to_unaligned32((uint32_t*)arg, lsa->u.sin.sin_addr.s_addr);
 343         free(lsa);
 344         return 1;
 345 }
 346
 347 /* udhcp_str2optset:
 348  * Parse string option representation to binary form and add it to opt_list.
 349  * Called to parse "udhcpc -x OPTNAME:OPTVAL"
 350  * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
 351  */
 352 /* helper for the helper */
 353 static char *allocate_tempopt_if_needed(
 354                 const struct dhcp_optflag *optflag,
 355                 char *buffer,
 356                 int *length_p)
 357 {
 358         char *allocated = NULL;
 359         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
 360                 const char *end;
 361                 allocated = xstrdup(buffer); /* more than enough */
 362                 end = hex2bin(allocated, buffer, 255);
 363                 if (errno)
 364                         bb_error_msg_and_die("malformed hex string '%s'", buffer);
 365                 *length_p = end - allocated;
 366         }
 367         return allocated;
 368 }
 369 /* helper: add an option to the opt_list */
 370 static NOINLINE void attach_option(
 371                 struct option_set **opt_list,
 372                 const struct dhcp_optflag *optflag,
 373                 char *buffer,
 374                 int length)
 375 {
 376         struct option_set *existing;
 377         char *allocated;
 378
 379         allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 380 #if ENABLE_FEATURE_UDHCP_RFC3397
 381         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 382                 /* reuse buffer and length for RFC1035-formatted string */
 383                 allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
 384         }
 385 #endif
 386
 387         existing = udhcp_find_option(*opt_list, optflag->code);
 388         if (!existing) {
 389                 struct option_set *new, **curr;
 390
 391                 /* make a new option */
 392                 log2("Attaching option %02x to list", optflag->code);
 393                 new = xmalloc(sizeof(*new));
 394                 new->data = xmalloc(length + OPT_DATA);
 395                 new->data[OPT_CODE] = optflag->code;
 396                 new->data[OPT_LEN] = length;
 397                 memcpy(new->data + OPT_DATA, (allocated ? allocated : buffer), length);
 398
 399                 curr = opt_list;
 400                 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
 401                         curr = &(*curr)->next;
 402
 403                 new->next = *curr;
 404                 *curr = new;
 405                 goto ret;
 406         }
 407
 408         if (optflag->flags & OPTION_LIST) {
 409                 unsigned old_len;
 410
 411                 /* add it to an existing option */
 412                 log2("Attaching option %02x to existing member of list", optflag->code);
 413                 old_len = existing->data[OPT_LEN];
 414                 if (old_len + length < 255) {
 415                         /* actually 255 is ok too, but adding a space can overlow it */
 416
 417                         existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
 418                         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
 419                          || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
 420                         ) {
 421                                 /* add space separator between STRING options in a list */
 422                                 existing->data[OPT_DATA + old_len] = ' ';
 423                                 old_len++;
 424                         }
 425                         memcpy(existing->data + OPT_DATA + old_len, (allocated ? allocated : buffer), length);
 426                         existing->data[OPT_LEN] = old_len + length;
 427                 } /* else, ignore the data, we could put this in a second option in the future */
 428         } /* else, ignore the new data */
 429
 430  ret:
 431         free(allocated);
 432 }
 433
 434 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
 435 {
 436         struct option_set **opt_list = arg;
 437         char *opt, *val;
 438         char *str;
 439         const struct dhcp_optflag *optflag;
 440         struct dhcp_optflag bin_optflag;
 441         unsigned optcode;
 442         int retval, length;
 443         /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
 444         char buffer[9] ALIGNED(4);
 445         uint16_t *result_u16 = (uint16_t *) buffer;
 446         uint32_t *result_u32 = (uint32_t *) buffer;
 447
 448         /* Cheat, the only *const* str possible is "" */
 449         str = (char *) const_str;
 450         opt = strtok(str, " \t=");
 451         if (!opt)
 452                 return 0;
 453
 454         optcode = bb_strtou(opt, NULL, 0);
 455         if (!errno && optcode < 255) {
 456                 /* Raw (numeric) option code */
 457                 bin_optflag.flags = OPTION_BIN;
 458                 bin_optflag.code = optcode;
 459                 optflag = &bin_optflag;
 460         } else {
 461                 optflag = &dhcp_optflags[udhcp_option_idx(opt)];
 462         }
 463
 464         retval = 0;
 465         do {
 466                 val = strtok(NULL, ", \t");
 467                 if (!val)
 468                         break;
 469                 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
 470                 retval = 0;
 471                 opt = buffer; /* new meaning for variable opt */
 472                 switch (optflag->flags & OPTION_TYPE_MASK) {
 473                 case OPTION_IP:
 474                         retval = udhcp_str2nip(val, buffer);
 475                         break;
 476                 case OPTION_IP_PAIR:
 477                         retval = udhcp_str2nip(val, buffer);
 478                         val = strtok(NULL, ", \t/-");
 479                         if (!val)
 480                                 retval = 0;
 481                         if (retval)
 482                                 retval = udhcp_str2nip(val, buffer + 4);
 483                         break;
 484                 case OPTION_STRING:
 485                 case OPTION_STRING_HOST:
 486 #if ENABLE_FEATURE_UDHCP_RFC3397
 487                 case OPTION_DNS_STRING:
 488 #endif
 489                         length = strnlen(val, 254);
 490                         if (length > 0) {
 491                                 opt = val;
 492                                 retval = 1;
 493                         }
 494                         break;
 495 //              case OPTION_BOOLEAN: {
 496 //                      static const char no_yes[] ALIGN1 = "no\0yes\0";
 497 //                      buffer[0] = retval = index_in_strings(no_yes, val);
 498 //                      retval++; /* 0 - bad; 1: "no" 2: "yes" */
 499 //                      break;
 500 //              }
 501                 case OPTION_U8:
 502                         buffer[0] = bb_strtou32(val, NULL, 0);
 503                         retval = (errno == 0);
 504                         break;
 505                 /* htonX are macros in older libc's, using temp var
 506                  * in code below for safety */
 507                 /* TODO: use bb_strtoX? */
 508                 case OPTION_U16: {
 509                         uint32_t tmp = bb_strtou32(val, NULL, 0);
 510                         *result_u16 = htons(tmp);
 511                         retval = (errno == 0 /*&& tmp < 0x10000*/);
 512                         break;
 513                 }
 514 //              case OPTION_S16: {
 515 //                      long tmp = bb_strtoi32(val, NULL, 0);
 516 //                      *result_u16 = htons(tmp);
 517 //                      retval = (errno == 0);
 518 //                      break;
 519 //              }
 520                 case OPTION_U32: {
 521                         uint32_t tmp = bb_strtou32(val, NULL, 0);
 522                         *result_u32 = htonl(tmp);
 523                         retval = (errno == 0);
 524                         break;
 525                 }
 526                 case OPTION_S32: {
 527                         int32_t tmp = bb_strtoi32(val, NULL, 0);
 528                         *result_u32 = htonl(tmp);
 529                         retval = (errno == 0);
 530                         break;
 531                 }
 532                 case OPTION_STATIC_ROUTES: {
 533                         /* Input: "a.b.c.d/m" */
 534                         /* Output: mask(1 byte),pfx(0-4 bytes),gw(4 bytes) */
 535                         unsigned mask;
 536                         char *slash = strchr(val, '/');
 537                         if (slash) {
 538                                 *slash = '\0';
 539                                 retval = udhcp_str2nip(val, buffer + 1);
 540                                 buffer[0] = mask = bb_strtou(slash + 1, NULL, 10);
 541                                 val = strtok(NULL, ", \t/-");
 542                                 if (!val || mask > 32 || errno)
 543                                         retval = 0;
 544                                 if (retval) {
 545                                         length = ((mask + 7) >> 3) + 5;
 546                                         retval = udhcp_str2nip(val, buffer + (length - 4));
 547                                 }
 548                         }
 549                         break;
 550                 }
 551                 case OPTION_BIN: /* handled in attach_option() */
 552                         opt = val;
 553                         retval = 1;
 554                 default:
 555                         break;
 556                 }
 557                 if (retval)
 558                         attach_option(opt_list, optflag, opt, length);
 559         } while (retval && (optflag->flags & OPTION_LIST));
 560
 561         return retval;
 562 }
 563
 564 /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
 565 int FAST_FUNC sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
 566 {
 567         char hexstrbuf[16 * 2];
 568         bin2hex(hexstrbuf, (void*)ip, 16);
 569         return sprintf(dest, /* "%s" */
 570                 "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
 571                 /* pre, */
 572                 hexstrbuf + 0 * 4,
 573                 hexstrbuf + 1 * 4,
 574                 hexstrbuf + 2 * 4,
 575                 hexstrbuf + 3 * 4,
 576                 hexstrbuf + 4 * 4,
 577                 hexstrbuf + 5 * 4,
 578                 hexstrbuf + 6 * 4,
 579                 hexstrbuf + 7 * 4
 580         );
 581 }