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_STRING                           , 0xd2 }, /* DHCP_PXE_PATH_PREFIX */
  67         { OPTION_6RD                              , 0xd4 }, /* DHCP_6RD           */
  68         { OPTION_STATIC_ROUTES | OPTION_LIST      , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
  69         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
  70
  71         /* Options below have no match in dhcp_option_strings[],
  72          * are not passed to dhcpc scripts, and cannot be specified
  73          * with "option XXX YYY" syntax in dhcpd config file.
  74          * These entries are only used internally by udhcp[cd]
  75          * to correctly encode options into packets.
  76          */
  77
  78         { OPTION_IP                               , 0x32 }, /* DHCP_REQUESTED_IP  */
  79         { OPTION_U8                               , 0x35 }, /* DHCP_MESSAGE_TYPE  */
  80         { OPTION_U16                              , 0x39 }, /* DHCP_MAX_SIZE      */
  81 //looks like these opts will work just fine even without these defs:
  82 //      { OPTION_STRING                           , 0x3c }, /* DHCP_VENDOR        */
  83 //      /* not really a string: */
  84 //      { OPTION_STRING                           , 0x3d }, /* DHCP_CLIENT_ID     */
  85         { 0, 0 } /* zeroed terminating entry */
  86 };
  87
  88 /* Used for converting options from incoming packets to env variables
  89  * for udhcpc stript, and for setting options for udhcpd via
  90  * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
  91  */
  92 /* Must match dhcp_optflags[] order */
  93 const char dhcp_option_strings[] ALIGN1 =
  94         "subnet" "\0"      /* DHCP_SUBNET         */
  95         "timezone" "\0"    /* DHCP_TIME_OFFSET    */
  96         "router" "\0"      /* DHCP_ROUTER         */
  97 //      "timesrv" "\0"     /* DHCP_TIME_SERVER    */
  98 //      "namesrv" "\0"     /* DHCP_NAME_SERVER    */
  99         "dns" "\0"         /* DHCP_DNS_SERVER     */
 100 //      "logsrv" "\0"      /* DHCP_LOG_SERVER     */
 101 //      "cookiesrv" "\0"   /* DHCP_COOKIE_SERVER  */
 102         "lprsrv" "\0"      /* DHCP_LPR_SERVER     */
 103         "hostname" "\0"    /* DHCP_HOST_NAME      */
 104         "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
 105         "domain" "\0"      /* DHCP_DOMAIN_NAME    */
 106         "swapsrv" "\0"     /* DHCP_SWAP_SERVER    */
 107         "rootpath" "\0"    /* DHCP_ROOT_PATH      */
 108         "ipttl" "\0"       /* DHCP_IP_TTL         */
 109         "mtu" "\0"         /* DHCP_MTU            */
 110         "broadcast" "\0"   /* DHCP_BROADCAST      */
 111         "routes" "\0"      /* DHCP_ROUTES         */
 112         "nisdomain" "\0"   /* DHCP_NIS_DOMAIN     */
 113         "nissrv" "\0"      /* DHCP_NIS_SERVER     */
 114         "ntpsrv" "\0"      /* DHCP_NTP_SERVER     */
 115         "wins" "\0"        /* DHCP_WINS_SERVER    */
 116         "lease" "\0"       /* DHCP_LEASE_TIME     */
 117         "serverid" "\0"    /* DHCP_SERVER_ID      */
 118         "message" "\0"     /* DHCP_ERR_MESSAGE    */
 119         "tftp" "\0"        /* DHCP_TFTP_SERVER_NAME */
 120         "bootfile" "\0"    /* DHCP_BOOT_FILE      */
 121 //      "userclass" "\0"   /* DHCP_USER_CLASS     */
 122 #if ENABLE_FEATURE_UDHCP_RFC3397
 123         "search" "\0"      /* DHCP_DOMAIN_SEARCH  */
 124 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
 125 // is not handled yet by "string->option" conversion code:
 126         "sipsrv" "\0"      /* DHCP_SIP_SERVERS    */
 127 #endif
 128         "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
 129 #if ENABLE_FEATURE_UDHCP_8021Q
 130         "vlanid" "\0"      /* DHCP_VLAN_ID        */
 131         "vlanpriority" "\0"/* DHCP_VLAN_PRIORITY  */
 132 #endif
 133         "pxeconffile" "\0" /* DHCP_PXE_CONF_FILE  */
 134         "pxepathprefix" "\0" /* DHCP_PXE_PATH_PREFIX  */
 135         "ip6rd" "\0"       /* DHCP_6RD            */
 136         "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
 137         "wpad" "\0"        /* DHCP_WPAD           */
 138         ;
 139
 140 /* Lengths of the option types in binary form.
 141  * Used by:
 142  * udhcp_str2optset: to determine how many bytes to allocate.
 143  * xmalloc_optname_optval: to estimate string length
 144  * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
 145  * is the number of elements, multiply it by one element's string width
 146  * (len_of_option_as_string[opt_type]) and you know how wide string you need.
 147  */
 148 const uint8_t dhcp_option_lengths[] ALIGN1 = {
 149         [OPTION_IP] =      4,
 150         [OPTION_IP_PAIR] = 8,
 151 //      [OPTION_BOOLEAN] = 1,
 152         [OPTION_STRING] =  1,  /* ignored by udhcp_str2optset */
 153         [OPTION_STRING_HOST] = 1,  /* ignored by udhcp_str2optset */
 154 #if ENABLE_FEATURE_UDHCP_RFC3397
 155         [OPTION_DNS_STRING] = 1,  /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
 156         [OPTION_SIP_SERVERS] = 1,
 157 #endif
 158         [OPTION_U8] =      1,
 159         [OPTION_U16] =     2,
 160 //      [OPTION_S16] =     2,
 161         [OPTION_U32] =     4,
 162         [OPTION_S32] =     4,
 163         /* Just like OPTION_STRING, we use minimum length here */
 164         [OPTION_STATIC_ROUTES] = 5,
 165         [OPTION_6RD] =    12,  /* ignored by udhcp_str2optset */
 166         /* The above value was chosen as follows:
 167          * len_of_option_as_string[] for this option is >60: it's a string of the form
 168          * "32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 ".
 169          * Each additional ipv4 address takes 4 bytes in binary option and appends
 170          * another "255.255.255.255 " 16-byte string. We can set [OPTION_6RD] = 4
 171          * but this severely overestimates string length: instead of 16 bytes,
 172          * it adds >60 for every 4 bytes in binary option.
 173          * We cheat and declare here that option is in units of 12 bytes.
 174          * This adds more than 60 bytes for every three ipv4 addresses - more than enough.
 175          * (Even 16 instead of 12 should work, but let's be paranoid).
 176          */
 177 };
 178
 179
 180 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
 181 static void log_option(const char *pfx, const uint8_t *opt)
 182 {
 183         if (dhcp_verbose >= 2) {
 184                 char buf[256 * 2 + 2];
 185                 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
 186                 bb_error_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
 187         }
 188 }
 189 #else
 190 # define log_option(pfx, opt) ((void)0)
 191 #endif
 192
 193 unsigned FAST_FUNC udhcp_option_idx(const char *name)
 194 {
 195         int n = index_in_strings(dhcp_option_strings, name);
 196         if (n >= 0)
 197                 return n;
 198
 199         {
 200                 char buf[sizeof(dhcp_option_strings)];
 201                 char *d = buf;
 202                 const char *s = dhcp_option_strings;
 203                 while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
 204                         *d++ = (*s == '\0' ? ' ' : *s);
 205                         s++;
 206                 }
 207                 *d = '\0';
 208                 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
 209         }
 210 }
 211
 212 /* Get an option with bounds checking (warning, result is not aligned) */
 213 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
 214 {
 215         uint8_t *optionptr;
 216         int len;
 217         int rem;
 218         int overload = 0;
 219         enum {
 220                 FILE_FIELD101  = FILE_FIELD  * 0x101,
 221                 SNAME_FIELD101 = SNAME_FIELD * 0x101,
 222         };
 223
 224         /* option bytes: [code][len][data1][data2]..[dataLEN] */
 225         optionptr = packet->options;
 226         rem = sizeof(packet->options);
 227         while (1) {
 228                 if (rem <= 0) {
 229                         bb_error_msg("bad packet, malformed option field");
 230                         return NULL;
 231                 }
 232                 if (optionptr[OPT_CODE] == DHCP_PADDING) {
 233                         rem--;
 234                         optionptr++;
 235                         continue;
 236                 }
 237                 if (optionptr[OPT_CODE] == DHCP_END) {
 238                         if ((overload & FILE_FIELD101) == FILE_FIELD) {
 239                                 /* can use packet->file, and didn't look at it yet */
 240                                 overload |= FILE_FIELD101; /* "we looked at it" */
 241                                 optionptr = packet->file;
 242                                 rem = sizeof(packet->file);
 243                                 continue;
 244                         }
 245                         if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
 246                                 /* can use packet->sname, and didn't look at it yet */
 247                                 overload |= SNAME_FIELD101; /* "we looked at it" */
 248                                 optionptr = packet->sname;
 249                                 rem = sizeof(packet->sname);
 250                                 continue;
 251                         }
 252                         break;
 253                 }
 254                 len = 2 + optionptr[OPT_LEN];
 255                 rem -= len;
 256                 if (rem < 0)
 257                         continue; /* complain and return NULL */
 258
 259                 if (optionptr[OPT_CODE] == code) {
 260                         log_option("option found", optionptr);
 261                         return optionptr + OPT_DATA;
 262                 }
 263
 264                 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
 265                         overload |= optionptr[OPT_DATA];
 266                         /* fall through */
 267                 }
 268                 optionptr += len;
 269         }
 270
 271         /* log3 because udhcpc uses it a lot - very noisy */
 272         log3("option 0x%02x not found", code);
 273         return NULL;
 274 }
 275
 276 /* Return the position of the 'end' option (no bounds checking) */
 277 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 278 {
 279         int i = 0;
 280
 281         while (optionptr[i] != DHCP_END) {
 282                 if (optionptr[i] != DHCP_PADDING)
 283                         i += optionptr[i + OPT_LEN] + OPT_DATA-1;
 284                 i++;
 285         }
 286         return i;
 287 }
 288
 289 /* Add an option (supplied in binary form) to the options.
 290  * Option format: [code][len][data1][data2]..[dataLEN]
 291  */
 292 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 293 {
 294         unsigned len;
 295         uint8_t *optionptr = packet->options;
 296         unsigned end = udhcp_end_option(optionptr);
 297
 298         len = OPT_DATA + addopt[OPT_LEN];
 299         /* end position + (option code/length + addopt length) + end option */
 300         if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
 301 //TODO: learn how to use overflow option if we exhaust packet->options[]
 302                 bb_error_msg("option 0x%02x did not fit into the packet",
 303                                 addopt[OPT_CODE]);
 304                 return;
 305         }
 306         log_option("adding option", addopt);
 307         memcpy(optionptr + end, addopt, len);
 308         optionptr[end + len] = DHCP_END;
 309 }
 310
 311 /* Add an one to four byte option to a packet */
 312 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
 313 {
 314         const struct dhcp_optflag *dh;
 315
 316         for (dh = dhcp_optflags; dh->code; dh++) {
 317                 if (dh->code == code) {
 318                         uint8_t option[6], len;
 319
 320                         option[OPT_CODE] = code;
 321                         len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
 322                         option[OPT_LEN] = len;
 323                         if (BB_BIG_ENDIAN)
 324                                 data <<= 8 * (4 - len);
 325                         /* Assignment is unaligned! */
 326                         move_to_unaligned32(&option[OPT_DATA], data);
 327                         udhcp_add_binary_option(packet, option);
 328                         return;
 329                 }
 330         }
 331
 332         bb_error_msg("can't add option 0x%02x", code);
 333 }
 334
 335 /* Find option 'code' in opt_list */
 336 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
 337 {
 338         while (opt_list && opt_list->data[OPT_CODE] < code)
 339                 opt_list = opt_list->next;
 340
 341         if (opt_list && opt_list->data[OPT_CODE] == code)
 342                 return opt_list;
 343         return NULL;
 344 }
 345
 346 /* Parse string to IP in network order */
 347 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
 348 {
 349         len_and_sockaddr *lsa;
 350
 351         lsa = host_and_af2sockaddr(str, 0, AF_INET);
 352         if (!lsa)
 353                 return 0;
 354         /* arg maybe unaligned */
 355         move_to_unaligned32((uint32_t*)arg, lsa->u.sin.sin_addr.s_addr);
 356         free(lsa);
 357         return 1;
 358 }
 359
 360 /* udhcp_str2optset:
 361  * Parse string option representation to binary form and add it to opt_list.
 362  * Called to parse "udhcpc -x OPTNAME:OPTVAL"
 363  * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
 364  */
 365 /* helper for the helper */
 366 static char *allocate_tempopt_if_needed(
 367                 const struct dhcp_optflag *optflag,
 368                 char *buffer,
 369                 int *length_p)
 370 {
 371         char *allocated = NULL;
 372         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
 373                 const char *end;
 374                 allocated = xstrdup(buffer); /* more than enough */
 375                 end = hex2bin(allocated, buffer, 255);
 376                 if (errno)
 377                         bb_error_msg_and_die("malformed hex string '%s'", buffer);
 378                 *length_p = end - allocated;
 379         }
 380         return allocated;
 381 }
 382 /* helper: add an option to the opt_list */
 383 static NOINLINE void attach_option(
 384                 struct option_set **opt_list,
 385                 const struct dhcp_optflag *optflag,
 386                 char *buffer,
 387                 int length)
 388 {
 389         struct option_set *existing;
 390         char *allocated;
 391
 392         allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
 393 #if ENABLE_FEATURE_UDHCP_RFC3397
 394         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 395                 /* reuse buffer and length for RFC1035-formatted string */
 396                 allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
 397         }
 398 #endif
 399
 400         existing = udhcp_find_option(*opt_list, optflag->code);
 401         if (!existing) {
 402                 struct option_set *new, **curr;
 403
 404                 /* make a new option */
 405                 log2("attaching option %02x to list", optflag->code);
 406                 new = xmalloc(sizeof(*new));
 407                 new->data = xmalloc(length + OPT_DATA);
 408                 new->data[OPT_CODE] = optflag->code;
 409                 new->data[OPT_LEN] = length;
 410                 memcpy(new->data + OPT_DATA, (allocated ? allocated : buffer), length);
 411
 412                 curr = opt_list;
 413                 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
 414                         curr = &(*curr)->next;
 415
 416                 new->next = *curr;
 417                 *curr = new;
 418                 goto ret;
 419         }
 420
 421         if (optflag->flags & OPTION_LIST) {
 422                 unsigned old_len;
 423
 424                 /* add it to an existing option */
 425                 log2("attaching option %02x to existing member of list", optflag->code);
 426                 old_len = existing->data[OPT_LEN];
 427                 if (old_len + length < 255) {
 428                         /* actually 255 is ok too, but adding a space can overlow it */
 429
 430                         existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
 431                         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
 432                          || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
 433                         ) {
 434                                 /* add space separator between STRING options in a list */
 435                                 existing->data[OPT_DATA + old_len] = ' ';
 436                                 old_len++;
 437                         }
 438                         memcpy(existing->data + OPT_DATA + old_len, (allocated ? allocated : buffer), length);
 439                         existing->data[OPT_LEN] = old_len + length;
 440                 } /* else, ignore the data, we could put this in a second option in the future */
 441         } /* else, ignore the new data */
 442
 443  ret:
 444         free(allocated);
 445 }
 446
 447 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
 448 {
 449         struct option_set **opt_list = arg;
 450         char *opt, *val;
 451         char *str;
 452         const struct dhcp_optflag *optflag;
 453         struct dhcp_optflag bin_optflag;
 454         unsigned optcode;
 455         int retval, length;
 456         /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
 457         char buffer[9] ALIGNED(4);
 458         uint16_t *result_u16 = (uint16_t *) buffer;
 459         uint32_t *result_u32 = (uint32_t *) buffer;
 460
 461         /* Cheat, the only *const* str possible is "" */
 462         str = (char *) const_str;
 463         opt = strtok(str, " \t=");
 464         if (!opt)
 465                 return 0;
 466
 467         optcode = bb_strtou(opt, NULL, 0);
 468         if (!errno && optcode < 255) {
 469                 /* Raw (numeric) option code */
 470                 bin_optflag.flags = OPTION_BIN;
 471                 bin_optflag.code = optcode;
 472                 optflag = &bin_optflag;
 473         } else {
 474                 optflag = &dhcp_optflags[udhcp_option_idx(opt)];
 475         }
 476
 477         retval = 0;
 478         do {
 479                 val = strtok(NULL, ", \t");
 480                 if (!val)
 481                         break;
 482                 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
 483                 retval = 0;
 484                 opt = buffer; /* new meaning for variable opt */
 485                 switch (optflag->flags & OPTION_TYPE_MASK) {
 486                 case OPTION_IP:
 487                         retval = udhcp_str2nip(val, buffer);
 488                         break;
 489                 case OPTION_IP_PAIR:
 490                         retval = udhcp_str2nip(val, buffer);
 491                         val = strtok(NULL, ", \t/-");
 492                         if (!val)
 493                                 retval = 0;
 494                         if (retval)
 495                                 retval = udhcp_str2nip(val, buffer + 4);
 496                         break;
 497                 case OPTION_STRING:
 498                 case OPTION_STRING_HOST:
 499 #if ENABLE_FEATURE_UDHCP_RFC3397
 500                 case OPTION_DNS_STRING:
 501 #endif
 502                         length = strnlen(val, 254);
 503                         if (length > 0) {
 504                                 opt = val;
 505                                 retval = 1;
 506                         }
 507                         break;
 508 //              case OPTION_BOOLEAN: {
 509 //                      static const char no_yes[] ALIGN1 = "no\0yes\0";
 510 //                      buffer[0] = retval = index_in_strings(no_yes, val);
 511 //                      retval++; /* 0 - bad; 1: "no" 2: "yes" */
 512 //                      break;
 513 //              }
 514                 case OPTION_U8:
 515                         buffer[0] = bb_strtou32(val, NULL, 0);
 516                         retval = (errno == 0);
 517                         break;
 518                 /* htonX are macros in older libc's, using temp var
 519                  * in code below for safety */
 520                 /* TODO: use bb_strtoX? */
 521                 case OPTION_U16: {
 522                         uint32_t tmp = bb_strtou32(val, NULL, 0);
 523                         *result_u16 = htons(tmp);
 524                         retval = (errno == 0 /*&& tmp < 0x10000*/);
 525                         break;
 526                 }
 527 //              case OPTION_S16: {
 528 //                      long tmp = bb_strtoi32(val, NULL, 0);
 529 //                      *result_u16 = htons(tmp);
 530 //                      retval = (errno == 0);
 531 //                      break;
 532 //              }
 533                 case OPTION_U32: {
 534                         uint32_t tmp = bb_strtou32(val, NULL, 0);
 535                         *result_u32 = htonl(tmp);
 536                         retval = (errno == 0);
 537                         break;
 538                 }
 539                 case OPTION_S32: {
 540                         int32_t tmp = bb_strtoi32(val, NULL, 0);
 541                         *result_u32 = htonl(tmp);
 542                         retval = (errno == 0);
 543                         break;
 544                 }
 545                 case OPTION_STATIC_ROUTES: {
 546                         /* Input: "a.b.c.d/m" */
 547                         /* Output: mask(1 byte),pfx(0-4 bytes),gw(4 bytes) */
 548                         unsigned mask;
 549                         char *slash = strchr(val, '/');
 550                         if (slash) {
 551                                 *slash = '\0';
 552                                 retval = udhcp_str2nip(val, buffer + 1);
 553                                 buffer[0] = mask = bb_strtou(slash + 1, NULL, 10);
 554                                 val = strtok(NULL, ", \t/-");
 555                                 if (!val || mask > 32 || errno)
 556                                         retval = 0;
 557                                 if (retval) {
 558                                         length = ((mask + 7) >> 3) + 5;
 559                                         retval = udhcp_str2nip(val, buffer + (length - 4));
 560                                 }
 561                         }
 562                         break;
 563                 }
 564                 case OPTION_BIN: /* handled in attach_option() */
 565                         opt = val;
 566                         retval = 1;
 567                 default:
 568                         break;
 569                 }
 570                 if (retval)
 571                         attach_option(opt_list, optflag, opt, length);
 572         } while (retval && (optflag->flags & OPTION_LIST));
 573
 574         return retval;
 575 }
 576
 577 /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
 578 int FAST_FUNC sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
 579 {
 580         char hexstrbuf[16 * 2];
 581         bin2hex(hexstrbuf, (void*)ip, 16);
 582         return sprintf(dest, /* "%s" */
 583                 "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
 584                 /* pre, */
 585                 hexstrbuf + 0 * 4,
 586                 hexstrbuf + 1 * 4,
 587                 hexstrbuf + 2 * 4,
 588                 hexstrbuf + 3 * 4,
 589                 hexstrbuf + 4 * 4,
 590                 hexstrbuf + 5 * 4,
 591                 hexstrbuf + 6 * 4,
 592                 hexstrbuf + 7 * 4
 593         );
 594 }