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 #if ENABLE_UDHCPC || ENABLE_UDHCPD
  18 /* Supported options are easily added here.
  19  * See RFC2132 for more options.
  20  * OPTION_REQ: these options are requested by udhcpc (unless -o).
  21  */
  22 const struct dhcp_optflag dhcp_optflags[] = {
  23         /* flags                                    code */
  24         { OPTION_IP                   | OPTION_REQ, 0x01 }, /* DHCP_SUBNET        */
  25         { OPTION_S32                              , 0x02 }, /* DHCP_TIME_OFFSET   */
  26         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x03 }, /* DHCP_ROUTER        */
  27 //      { OPTION_IP | OPTION_LIST                 , 0x04 }, /* DHCP_TIME_SERVER   */
  28 //      { OPTION_IP | OPTION_LIST                 , 0x05 }, /* DHCP_NAME_SERVER   */
  29         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x06 }, /* DHCP_DNS_SERVER    */
  30 //      { OPTION_IP | OPTION_LIST                 , 0x07 }, /* DHCP_LOG_SERVER    */
  31 //      { OPTION_IP | OPTION_LIST                 , 0x08 }, /* DHCP_COOKIE_SERVER */
  32         { OPTION_IP | OPTION_LIST                 , 0x09 }, /* DHCP_LPR_SERVER    */
  33         { OPTION_STRING_HOST          | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME     */
  34         { OPTION_U16                              , 0x0d }, /* DHCP_BOOT_SIZE     */
  35         { OPTION_STRING_HOST          | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME   */
  36         { OPTION_IP                               , 0x10 }, /* DHCP_SWAP_SERVER   */
  37         { OPTION_STRING                           , 0x11 }, /* DHCP_ROOT_PATH     */
  38         { OPTION_U8                               , 0x17 }, /* DHCP_IP_TTL        */
  39         { OPTION_U16                              , 0x1a }, /* DHCP_MTU           */
  40 //TODO: why do we request DHCP_BROADCAST? Can't we assume that
  41 //in the unlikely case it is different from typical N.N.255.255,
  42 //server would let us know anyway?
  43         { OPTION_IP                   | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST     */
  44         { OPTION_IP_PAIR | OPTION_LIST            , 0x21 }, /* DHCP_ROUTES        */
  45         { OPTION_STRING_HOST                      , 0x28 }, /* DHCP_NIS_DOMAIN    */
  46         { OPTION_IP | OPTION_LIST                 , 0x29 }, /* DHCP_NIS_SERVER    */
  47         { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER    */
  48         { OPTION_IP | OPTION_LIST                 , 0x2c }, /* DHCP_WINS_SERVER   */
  49         { OPTION_U32                              , 0x33 }, /* DHCP_LEASE_TIME    */
  50         { OPTION_IP                               , 0x36 }, /* DHCP_SERVER_ID     */
  51         { OPTION_STRING                           , 0x38 }, /* DHCP_ERR_MESSAGE   */
  52 //TODO: must be combined with 'sname' and 'file' handling:
  53         { OPTION_STRING_HOST                      , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
  54         { OPTION_STRING                           , 0x43 }, /* DHCP_BOOT_FILE     */
  55 //TODO: not a string, but a set of LASCII strings:
  56 //      { OPTION_STRING                           , 0x4D }, /* DHCP_USER_CLASS    */
  57 #if ENABLE_FEATURE_UDHCP_RFC3397
  58         { OPTION_DNS_STRING | OPTION_LIST         , 0x77 }, /* DHCP_DOMAIN_SEARCH */
  59         { OPTION_SIP_SERVERS                      , 0x78 }, /* DHCP_SIP_SERVERS   */
  60 #endif
  61         { OPTION_STATIC_ROUTES | OPTION_LIST      , 0x79 }, /* DHCP_STATIC_ROUTES */
  62 #if ENABLE_FEATURE_UDHCP_8021Q
  63         { OPTION_U16                              , 0x84 }, /* DHCP_VLAN_ID       */
  64         { OPTION_U8                               , 0x85 }, /* DHCP_VLAN_PRIORITY */
  65 #endif
  66         { OPTION_STRING                           , 0xd1 }, /* DHCP_PXE_CONF_FILE */
  67         { OPTION_STRING                           , 0xd2 }, /* DHCP_PXE_PATH_PREFIX */
  68         { OPTION_U32                              , 0xd3 }, /* DHCP_REBOOT_TIME   */
  69         { OPTION_6RD                              , 0xd4 }, /* DHCP_6RD           */
  70         { OPTION_STATIC_ROUTES | OPTION_LIST      , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
  71         { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
  72
  73         /* Options below have no match in dhcp_option_strings[],
  74          * are not passed to dhcpc scripts, and cannot be specified
  75          * with "option XXX YYY" syntax in dhcpd config file.
  76          * These entries are only used internally by udhcp[cd]
  77          * to correctly encode options into packets.
  78          */
  79
  80         { OPTION_IP                               , 0x32 }, /* DHCP_REQUESTED_IP  */
  81         { OPTION_U8                               , 0x35 }, /* DHCP_MESSAGE_TYPE  */
  82         { OPTION_U16                              , 0x39 }, /* DHCP_MAX_SIZE      */
  83 //looks like these opts will work just fine even without these defs:
  84 //      { OPTION_STRING                           , 0x3c }, /* DHCP_VENDOR        */
  85 //      /* not really a string: */
  86 //      { OPTION_STRING                           , 0x3d }, /* DHCP_CLIENT_ID     */
  87         { 0, 0 } /* zeroed terminating entry */
  88 };
  89
  90 /* Used for converting options from incoming packets to env variables
  91  * for udhcpc script, and for setting options for udhcpd via
  92  * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
  93  */
  94 /* Must match dhcp_optflags[] order */
  95 const char dhcp_option_strings[] ALIGN1 =
  96         "subnet" "\0"           /* DHCP_SUBNET          */
  97         "timezone" "\0"         /* DHCP_TIME_OFFSET     */
  98         "router" "\0"           /* DHCP_ROUTER          */
  99 //      "timesrv" "\0"          /* DHCP_TIME_SERVER     */
 100 //      "namesrv" "\0"          /* DHCP_NAME_SERVER     */
 101         "dns" "\0"              /* DHCP_DNS_SERVER      */
 102 //      "logsrv" "\0"           /* DHCP_LOG_SERVER      */
 103 //      "cookiesrv" "\0"        /* DHCP_COOKIE_SERVER   */
 104         "lprsrv" "\0"           /* DHCP_LPR_SERVER      */
 105         "hostname" "\0"         /* DHCP_HOST_NAME       */
 106         "bootsize" "\0"         /* DHCP_BOOT_SIZE       */
 107         "domain" "\0"           /* DHCP_DOMAIN_NAME     */
 108         "swapsrv" "\0"          /* DHCP_SWAP_SERVER     */
 109         "rootpath" "\0"         /* DHCP_ROOT_PATH       */
 110         "ipttl" "\0"            /* DHCP_IP_TTL          */
 111         "mtu" "\0"              /* DHCP_MTU             */
 112         "broadcast" "\0"        /* DHCP_BROADCAST       */
 113         "routes" "\0"           /* DHCP_ROUTES          */
 114         "nisdomain" "\0"        /* DHCP_NIS_DOMAIN      */
 115         "nissrv" "\0"           /* DHCP_NIS_SERVER      */
 116         "ntpsrv" "\0"           /* DHCP_NTP_SERVER      */
 117         "wins" "\0"             /* DHCP_WINS_SERVER     */
 118         "lease" "\0"            /* DHCP_LEASE_TIME      */
 119         "serverid" "\0"         /* DHCP_SERVER_ID       */
 120         "message" "\0"          /* DHCP_ERR_MESSAGE     */
 121         "tftp" "\0"             /* DHCP_TFTP_SERVER_NAME*/
 122         "bootfile" "\0"         /* DHCP_BOOT_FILE       */
 123 //      "userclass" "\0"        /* DHCP_USER_CLASS      */
 124 #if ENABLE_FEATURE_UDHCP_RFC3397
 125         "search" "\0"           /* DHCP_DOMAIN_SEARCH   */
 126 // doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
 127 // is not handled yet by "string->option" conversion code:
 128         "sipsrv" "\0"           /* DHCP_SIP_SERVERS     */
 129 #endif
 130         "staticroutes" "\0"     /* DHCP_STATIC_ROUTES   */
 131 #if ENABLE_FEATURE_UDHCP_8021Q
 132         "vlanid" "\0"           /* DHCP_VLAN_ID         */
 133         "vlanpriority" "\0"     /* DHCP_VLAN_PRIORITY   */
 134 #endif
 135         "pxeconffile" "\0"      /* DHCP_PXE_CONF_FILE   */
 136         "pxepathprefix" "\0"    /* DHCP_PXE_PATH_PREFIX */
 137         "reboottime" "\0"       /* DHCP_REBOOT_TIME     */
 138         "ip6rd" "\0"            /* DHCP_6RD             */
 139         "msstaticroutes" "\0"   /* DHCP_MS_STATIC_ROUTES*/
 140         "wpad" "\0"             /* DHCP_WPAD            */
 141         ;
 142 #endif
 143
 144 /* Lengths of the option types in binary form.
 145  * Used by:
 146  * udhcp_str2optset: to determine how many bytes to allocate.
 147  * xmalloc_optname_optval: to estimate string length
 148  * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
 149  * is the number of elements, multiply it by one element's string width
 150  * (len_of_option_as_string[opt_type]) and you know how wide string you need.
 151  */
 152 const uint8_t dhcp_option_lengths[] ALIGN1 = {
 153         [OPTION_IP] =      4,
 154         [OPTION_IP_PAIR] = 8,
 155 //      [OPTION_BOOLEAN] = 1,
 156         [OPTION_STRING] =  1,  /* ignored by udhcp_str2optset */
 157         [OPTION_STRING_HOST] = 1,  /* ignored by udhcp_str2optset */
 158 #if ENABLE_FEATURE_UDHCP_RFC3397
 159         [OPTION_DNS_STRING] = 1,  /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
 160         [OPTION_SIP_SERVERS] = 1,
 161 #endif
 162         [OPTION_U8] =      1,
 163         [OPTION_U16] =     2,
 164 //      [OPTION_S16] =     2,
 165         [OPTION_U32] =     4,
 166         [OPTION_S32] =     4,
 167         /* Just like OPTION_STRING, we use minimum length here */
 168         [OPTION_STATIC_ROUTES] = 5,
 169         [OPTION_6RD] =    12,  /* ignored by udhcp_str2optset */
 170         /* The above value was chosen as follows:
 171          * len_of_option_as_string[] for this option is >60: it's a string of the form
 172          * "32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 ".
 173          * Each additional ipv4 address takes 4 bytes in binary option and appends
 174          * another "255.255.255.255 " 16-byte string. We can set [OPTION_6RD] = 4
 175          * but this severely overestimates string length: instead of 16 bytes,
 176          * it adds >60 for every 4 bytes in binary option.
 177          * We cheat and declare here that option is in units of 12 bytes.
 178          * This adds more than 60 bytes for every three ipv4 addresses - more than enough.
 179          * (Even 16 instead of 12 should work, but let's be paranoid).
 180          */
 181 };
 182
 183
 184 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
 185 static void log_option(const char *pfx, const uint8_t *opt)
 186 {
 187         if (dhcp_verbose >= 2) {
 188                 char buf[256 * 2 + 2];
 189                 *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
 190                 bb_error_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
 191         }
 192 }
 193 #else
 194 # define log_option(pfx, opt) ((void)0)
 195 #endif
 196
 197 unsigned FAST_FUNC udhcp_option_idx(const char *name, const char *option_strings)
 198 {
 199         int n = index_in_strings(option_strings, name);
 200         if (n >= 0)
 201                 return n;
 202
 203         {
 204                 char *buf, *d;
 205                 const char *s;
 206
 207                 s = option_strings;
 208                 while (*s)
 209                         s += strlen(s) + 1;
 210
 211                 d = buf = xzalloc(s - option_strings);
 212                 s = option_strings;
 213                 while (!(*s == '\0' && s[1] == '\0')) {
 214                         *d++ = (*s == '\0' ? ' ' : *s);
 215                         s++;
 216                 }
 217                 bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
 218         }
 219 }
 220
 221 /* Get an option with bounds checking (warning, result is not aligned) */
 222 uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
 223 {
 224         uint8_t *optionptr;
 225         int len;
 226         int rem;
 227         int overload = 0;
 228         enum {
 229                 FILE_FIELD101  = FILE_FIELD  * 0x101,
 230                 SNAME_FIELD101 = SNAME_FIELD * 0x101,
 231         };
 232
 233         /* option bytes: [code][len][data1][data2]..[dataLEN] */
 234         optionptr = packet->options;
 235         rem = sizeof(packet->options);
 236         while (1) {
 237                 if (rem <= 0) {
 238  complain:
 239                         bb_error_msg("bad packet, malformed option field");
 240                         return NULL;
 241                 }
 242
 243                 /* DHCP_PADDING and DHCP_END have no [len] byte */
 244                 if (optionptr[OPT_CODE] == DHCP_PADDING) {
 245                         rem--;
 246                         optionptr++;
 247                         continue;
 248                 }
 249                 if (optionptr[OPT_CODE] == DHCP_END) {
 250                         if ((overload & FILE_FIELD101) == FILE_FIELD) {
 251                                 /* can use packet->file, and didn't look at it yet */
 252                                 overload |= FILE_FIELD101; /* "we looked at it" */
 253                                 optionptr = packet->file;
 254                                 rem = sizeof(packet->file);
 255                                 continue;
 256                         }
 257                         if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
 258                                 /* can use packet->sname, and didn't look at it yet */
 259                                 overload |= SNAME_FIELD101; /* "we looked at it" */
 260                                 optionptr = packet->sname;
 261                                 rem = sizeof(packet->sname);
 262                                 continue;
 263                         }
 264                         break;
 265                 }
 266
 267                 if (rem <= OPT_LEN)
 268                         goto complain; /* complain and return NULL */
 269                 len = 2 + optionptr[OPT_LEN];
 270                 rem -= len;
 271                 if (rem < 0)
 272                         goto complain; /* complain and return NULL */
 273
 274                 if (optionptr[OPT_CODE] == code) {
 275                         if (optionptr[OPT_LEN] == 0) {
 276                                 /* So far no valid option with length 0 known.
 277                                  * Having this check means that searching
 278                                  * for DHCP_MESSAGE_TYPE need not worry
 279                                  * that returned pointer might be unsafe
 280                                  * to dereference.
 281                                  */
 282                                 goto complain; /* complain and return NULL */
 283                         }
 284                         log_option("option found", optionptr);
 285                         return optionptr + OPT_DATA;
 286                 }
 287
 288                 if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
 289                         if (len >= 3)
 290                                 overload |= optionptr[OPT_DATA];
 291                         /* fall through */
 292                 }
 293                 optionptr += len;
 294         }
 295
 296         /* log3 because udhcpc uses it a lot - very noisy */
 297         log3("option 0x%02x not found", code);
 298         return NULL;
 299 }
 300
 301 uint8_t* FAST_FUNC udhcp_get_option32(struct dhcp_packet *packet, int code)
 302 {
 303         uint8_t *r = udhcp_get_option(packet, code);
 304         if (r) {
 305                 if (r[-1] != 4)
 306                         r = NULL;
 307         }
 308         return r;
 309 }
 310
 311 /* Return the position of the 'end' option (no bounds checking) */
 312 int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 313 {
 314         int i = 0;
 315
 316         while (optionptr[i] != DHCP_END) {
 317                 if (optionptr[i] != DHCP_PADDING)
 318                         i += optionptr[i + OPT_LEN] + OPT_DATA-1;
 319                 i++;
 320         }
 321         return i;
 322 }
 323
 324 /* Add an option (supplied in binary form) to the options.
 325  * Option format: [code][len][data1][data2]..[dataLEN]
 326  */
 327 void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 328 {
 329         unsigned len;
 330         uint8_t *optionptr = packet->options;
 331         unsigned end = udhcp_end_option(optionptr);
 332
 333         len = OPT_DATA + addopt[OPT_LEN];
 334         /* end position + (option code/length + addopt length) + end option */
 335         if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
 336 //TODO: learn how to use overflow option if we exhaust packet->options[]
 337                 bb_error_msg("option 0x%02x did not fit into the packet",
 338                                 addopt[OPT_CODE]);
 339                 return;
 340         }
 341         log_option("adding option", addopt);
 342         memcpy(optionptr + end, addopt, len);
 343         optionptr[end + len] = DHCP_END;
 344 }
 345
 346 #if ENABLE_UDHCPC || ENABLE_UDHCPD
 347 /* Add an one to four byte option to a packet */
 348 void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
 349 {
 350         const struct dhcp_optflag *dh;
 351
 352         for (dh = dhcp_optflags; dh->code; dh++) {
 353                 if (dh->code == code) {
 354                         uint8_t option[6], len;
 355
 356                         option[OPT_CODE] = code;
 357                         len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
 358                         option[OPT_LEN] = len;
 359                         if (BB_BIG_ENDIAN)
 360                                 data <<= 8 * (4 - len);
 361                         /* Assignment is unaligned! */
 362                         move_to_unaligned32(&option[OPT_DATA], data);
 363                         udhcp_add_binary_option(packet, option);
 364                         return;
 365                 }
 366         }
 367
 368         bb_error_msg("can't add option 0x%02x", code);
 369 }
 370 #endif
 371
 372 /* Find option 'code' in opt_list */
 373 struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
 374 {
 375         while (opt_list && opt_list->data[OPT_CODE] < code)
 376                 opt_list = opt_list->next;
 377
 378         if (opt_list && opt_list->data[OPT_CODE] == code)
 379                 return opt_list;
 380         return NULL;
 381 }
 382
 383 /* Parse string to IP in network order */
 384 int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
 385 {
 386         len_and_sockaddr *lsa;
 387
 388         lsa = host_and_af2sockaddr(str, 0, AF_INET);
 389         if (!lsa)
 390                 return 0;
 391         /* arg maybe unaligned */
 392         move_to_unaligned32((uint32_t*)arg, lsa->u.sin.sin_addr.s_addr);
 393         free(lsa);
 394         return 1;
 395 }
 396
 397 /* udhcp_str2optset:
 398  * Parse string option representation to binary form and add it to opt_list.
 399  * Called to parse "udhcpc -x OPTNAME:OPTVAL"
 400  * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
 401  */
 402 /* helper: add an option to the opt_list */
 403 #if !ENABLE_UDHCPC6
 404 #define attach_option(opt_list, optflag, buffer, length, dhcpv6) \
 405         attach_option(opt_list, optflag, buffer, length)
 406 #endif
 407 static NOINLINE void attach_option(
 408                 struct option_set **opt_list,
 409                 const struct dhcp_optflag *optflag,
 410                 char *buffer,
 411                 int length,
 412                 bool dhcpv6)
 413 {
 414         IF_NOT_UDHCPC6(bool dhcpv6 = 0;)
 415         struct option_set *existing;
 416         char *allocated = NULL;
 417
 418         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
 419                 const char *end;
 420                 allocated = xstrdup(buffer); /* more than enough */
 421                 end = hex2bin(allocated, buffer, 255);
 422                 if (errno)
 423                         bb_error_msg_and_die("malformed hex string '%s'", buffer);
 424                 length = end - allocated;
 425                 buffer = allocated;
 426         }
 427 #if ENABLE_FEATURE_UDHCP_RFC3397
 428         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
 429                 /* reuse buffer and length for RFC1035-formatted string */
 430                 allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
 431         }
 432 #endif
 433
 434         existing = udhcp_find_option(*opt_list, optflag->code);
 435         if (!existing) {
 436                 struct option_set *new, **curr;
 437
 438                 /* make a new option */
 439                 log2("attaching option %02x to list", optflag->code);
 440                 new = xmalloc(sizeof(*new));
 441                 if (!dhcpv6) {
 442                         new->data = xmalloc(length + OPT_DATA);
 443                         new->data[OPT_CODE] = optflag->code;
 444                         new->data[OPT_LEN] = length;
 445                         memcpy(new->data + OPT_DATA, buffer, length);
 446                 } else {
 447                         new->data = xmalloc(length + D6_OPT_DATA);
 448                         new->data[D6_OPT_CODE] = optflag->code >> 8;
 449                         new->data[D6_OPT_CODE + 1] = optflag->code & 0xff;
 450                         new->data[D6_OPT_LEN] = length >> 8;
 451                         new->data[D6_OPT_LEN + 1] = length & 0xff;
 452                         memcpy(new->data + D6_OPT_DATA, buffer,
 453                                         length);
 454                 }
 455
 456                 curr = opt_list;
 457                 while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
 458                         curr = &(*curr)->next;
 459
 460                 new->next = *curr;
 461                 *curr = new;
 462                 goto ret;
 463         }
 464
 465         if (optflag->flags & OPTION_LIST) {
 466                 unsigned old_len;
 467
 468                 /* add it to an existing option */
 469                 log2("attaching option %02x to existing member of list", optflag->code);
 470                 old_len = existing->data[OPT_LEN];
 471                 if (old_len + length < 255) {
 472                         /* actually 255 is ok too, but adding a space can overlow it */
 473
 474                         existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
 475 // So far dhcp_optflags[] has no OPTION_STRING[_HOST] | OPTION_LIST items
 476 #if 0
 477                         if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
 478                          || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
 479                         ) {
 480                                 /* add space separator between STRING options in a list */
 481                                 existing->data[OPT_DATA + old_len] = ' ';
 482                                 old_len++;
 483                         }
 484 #endif
 485
 486                         memcpy(existing->data + OPT_DATA + old_len, buffer, length);
 487                         existing->data[OPT_LEN] = old_len + length;
 488                 } /* else, ignore the data, we could put this in a second option in the future */
 489         } /* else, ignore the new data */
 490
 491  ret:
 492         free(allocated);
 493 }
 494
 495 int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg,
 496                 const struct dhcp_optflag *optflags, const char *option_strings,
 497                 bool dhcpv6)
 498 {
 499         struct option_set **opt_list = arg;
 500         char *opt;
 501         char *str;
 502         const struct dhcp_optflag *optflag;
 503         struct dhcp_optflag userdef_optflag;
 504         unsigned optcode;
 505         int retval;
 506         /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
 507         char buffer[9] ALIGNED(4);
 508         uint16_t *result_u16 = (uint16_t *) buffer;
 509         uint32_t *result_u32 = (uint32_t *) buffer;
 510
 511         /* Cheat, the only *const* str possible is "" */
 512         str = (char *) const_str;
 513         opt = strtok(str, " \t=:");
 514         if (!opt)
 515                 return 0;
 516
 517         optcode = bb_strtou(opt, NULL, 0);
 518         if (!errno && optcode < 255) {
 519                 /* Raw (numeric) option code.
 520                  * Initially assume binary (hex-str), but if "str" or 'str'
 521                  * is seen later, switch to STRING.
 522                  */
 523                 userdef_optflag.flags = OPTION_BIN;
 524                 userdef_optflag.code = optcode;
 525                 optflag = &userdef_optflag;
 526         } else {
 527                 optflag = &optflags[udhcp_option_idx(opt, option_strings)];
 528         }
 529
 530         /* Loop to handle OPTION_LIST case, else execute just once */
 531         retval = 0;
 532         do {
 533                 int length;
 534                 char *val;
 535
 536                 if (optflag->flags == OPTION_BIN) {
 537                         val = strtok(NULL, ""); /* do not split "'q w e'" */
 538                         trim(val);
 539                 } else
 540                         val = strtok(NULL, ", \t");
 541                 if (!val)
 542                         break;
 543
 544                 length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
 545                 retval = 0;
 546                 opt = buffer; /* new meaning for variable opt */
 547
 548                 switch (optflag->flags & OPTION_TYPE_MASK) {
 549                 case OPTION_IP:
 550                         retval = udhcp_str2nip(val, buffer);
 551                         break;
 552                 case OPTION_IP_PAIR:
 553                         retval = udhcp_str2nip(val, buffer);
 554                         val = strtok(NULL, ", \t/-");
 555                         if (!val)
 556                                 retval = 0;
 557                         if (retval)
 558                                 retval = udhcp_str2nip(val, buffer + 4);
 559                         break;
 560  case_OPTION_STRING:
 561                 case OPTION_STRING:
 562                 case OPTION_STRING_HOST:
 563 #if ENABLE_FEATURE_UDHCP_RFC3397
 564                 case OPTION_DNS_STRING:
 565 #endif
 566                         length = strnlen(val, 254);
 567                         if (length > 0) {
 568                                 opt = val;
 569                                 retval = 1;
 570                         }
 571                         break;
 572 //              case OPTION_BOOLEAN: {
 573 //                      static const char no_yes[] ALIGN1 = "no\0yes\0";
 574 //                      buffer[0] = retval = index_in_strings(no_yes, val);
 575 //                      retval++; /* 0 - bad; 1: "no" 2: "yes" */
 576 //                      break;
 577 //              }
 578                 case OPTION_U8:
 579                         buffer[0] = bb_strtou32(val, NULL, 0);
 580                         retval = (errno == 0);
 581                         break;
 582                 /* htonX are macros in older libc's, using temp var
 583                  * in code below for safety */
 584                 /* TODO: use bb_strtoX? */
 585                 case OPTION_U16: {
 586                         uint32_t tmp = bb_strtou32(val, NULL, 0);
 587                         *result_u16 = htons(tmp);
 588                         retval = (errno == 0 /*&& tmp < 0x10000*/);
 589                         break;
 590                 }
 591 //              case OPTION_S16: {
 592 //                      long tmp = bb_strtoi32(val, NULL, 0);
 593 //                      *result_u16 = htons(tmp);
 594 //                      retval = (errno == 0);
 595 //                      break;
 596 //              }
 597                 case OPTION_U32: {
 598                         uint32_t tmp = bb_strtou32(val, NULL, 0);
 599                         *result_u32 = htonl(tmp);
 600                         retval = (errno == 0);
 601                         break;
 602                 }
 603                 case OPTION_S32: {
 604                         int32_t tmp = bb_strtoi32(val, NULL, 0);
 605                         *result_u32 = htonl(tmp);
 606                         retval = (errno == 0);
 607                         break;
 608                 }
 609                 case OPTION_STATIC_ROUTES: {
 610                         /* Input: "a.b.c.d/m" */
 611                         /* Output: mask(1 byte),pfx(0-4 bytes),gw(4 bytes) */
 612                         unsigned mask;
 613                         char *slash = strchr(val, '/');
 614                         if (slash) {
 615                                 *slash = '\0';
 616                                 retval = udhcp_str2nip(val, buffer + 1);
 617                                 buffer[0] = mask = bb_strtou(slash + 1, NULL, 10);
 618                                 val = strtok(NULL, ", \t/-");
 619                                 if (!val || mask > 32 || errno)
 620                                         retval = 0;
 621                                 if (retval) {
 622                                         length = ((mask + 7) >> 3) + 5;
 623                                         retval = udhcp_str2nip(val, buffer + (length - 4));
 624                                 }
 625                         }
 626                         break;
 627                 }
 628                 case OPTION_BIN:
 629                         /* Raw (numeric) option code. Is it a string? */
 630                         if (val[0] == '"' || val[0] == '\'') {
 631                                 char delim = val[0];
 632                                 char *end = last_char_is(val + 1, delim);
 633                                 if (end) {
 634                                         *end = '\0';
 635                                         val++;
 636                                         userdef_optflag.flags = OPTION_STRING;
 637                                         goto case_OPTION_STRING;
 638                                 }
 639                         }
 640                         /* No: hex-str option, handled in attach_option() */
 641                         opt = val;
 642                         retval = 1;
 643                         break;
 644                 default:
 645                         break;
 646                 }
 647
 648                 if (retval)
 649                         attach_option(opt_list, optflag, opt, length, dhcpv6);
 650         } while (retval && (optflag->flags & OPTION_LIST));
 651
 652         return retval;
 653 }
 654
 655 /* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
 656 int FAST_FUNC sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
 657 {
 658         char hexstrbuf[16 * 2];
 659         bin2hex(hexstrbuf, (void*)ip, 16);
 660         return sprintf(dest, /* "%s" */
 661                 "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
 662                 /* pre, */
 663                 hexstrbuf + 0 * 4,
 664                 hexstrbuf + 1 * 4,
 665                 hexstrbuf + 2 * 4,
 666                 hexstrbuf + 3 * 4,
 667                 hexstrbuf + 4 * 4,
 668                 hexstrbuf + 5 * 4,
 669                 hexstrbuf + 6 * 4,
 670                 hexstrbuf + 7 * 4
 671         );
 672 }