ip link: add support for "address ETHADDR". Closes 4862
[oweals/busybox.git] / networking / udhcp / common.c
index 7b2e19c4248128c3c7aa37cc9107d5415b25063e..fe322db4ffed64851528b9aae06a6760e90eb52a 100644 (file)
 /* vi: set sw=4 ts=4: */
-/* common.c
+/*
+ * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
  *
- * Functions for debugging and logging as well as some other
- * simple helper functions.
- *
- * Russ Dill <Russ.Dill@asu.edu> 2001-2003
- * Rewritten by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
- *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
  */
+#include "common.h"
 
-#include <syslog.h>
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+unsigned dhcp_verbose;
+#endif
 
-#include "common.h"
+const uint8_t MAC_BCAST_ADDR[6] ALIGN2 = {
+       0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+};
+
+/* Supported options are easily added here.
+ * See RFC2132 for more options.
+ * OPTION_REQ: these options are requested by udhcpc (unless -o).
+ */
+const struct dhcp_optflag dhcp_optflags[] = {
+       /* flags                                    code */
+       { OPTION_IP                   | OPTION_REQ, 0x01 }, /* DHCP_SUBNET        */
+       { OPTION_S32                              , 0x02 }, /* DHCP_TIME_OFFSET   */
+       { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x03 }, /* DHCP_ROUTER        */
+//     { OPTION_IP | OPTION_LIST                 , 0x04 }, /* DHCP_TIME_SERVER   */
+//     { OPTION_IP | OPTION_LIST                 , 0x05 }, /* DHCP_NAME_SERVER   */
+       { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x06 }, /* DHCP_DNS_SERVER    */
+//     { OPTION_IP | OPTION_LIST                 , 0x07 }, /* DHCP_LOG_SERVER    */
+//     { OPTION_IP | OPTION_LIST                 , 0x08 }, /* DHCP_COOKIE_SERVER */
+       { OPTION_IP | OPTION_LIST                 , 0x09 }, /* DHCP_LPR_SERVER    */
+       { OPTION_STRING_HOST          | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME     */
+       { OPTION_U16                              , 0x0d }, /* DHCP_BOOT_SIZE     */
+       { OPTION_STRING_HOST          | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME   */
+       { OPTION_IP                               , 0x10 }, /* DHCP_SWAP_SERVER   */
+       { OPTION_STRING                           , 0x11 }, /* DHCP_ROOT_PATH     */
+       { OPTION_U8                               , 0x17 }, /* DHCP_IP_TTL        */
+       { OPTION_U16                              , 0x1a }, /* DHCP_MTU           */
+//TODO: why do we request DHCP_BROADCAST? Can't we assume that
+//in the unlikely case it is different from typical N.N.255.255,
+//server would let us know anyway?
+       { OPTION_IP                   | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST     */
+       { OPTION_IP_PAIR | OPTION_LIST            , 0x21 }, /* DHCP_ROUTES        */
+       { OPTION_STRING_HOST                      , 0x28 }, /* DHCP_NIS_DOMAIN    */
+       { OPTION_IP | OPTION_LIST                 , 0x29 }, /* DHCP_NIS_SERVER    */
+       { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER    */
+       { OPTION_IP | OPTION_LIST                 , 0x2c }, /* DHCP_WINS_SERVER   */
+       { OPTION_U32                              , 0x33 }, /* DHCP_LEASE_TIME    */
+       { OPTION_IP                               , 0x36 }, /* DHCP_SERVER_ID     */
+       { OPTION_STRING                           , 0x38 }, /* DHCP_ERR_MESSAGE   */
+//TODO: must be combined with 'sname' and 'file' handling:
+       { OPTION_STRING_HOST                      , 0x42 }, /* DHCP_TFTP_SERVER_NAME */
+       { OPTION_STRING                           , 0x43 }, /* DHCP_BOOT_FILE     */
+//TODO: not a string, but a set of LASCII strings:
+//     { OPTION_STRING                           , 0x4D }, /* DHCP_USER_CLASS    */
+#if ENABLE_FEATURE_UDHCP_RFC3397
+       { OPTION_DNS_STRING | OPTION_LIST         , 0x77 }, /* DHCP_DOMAIN_SEARCH */
+       { OPTION_SIP_SERVERS                      , 0x78 }, /* DHCP_SIP_SERVERS   */
+#endif
+       { OPTION_STATIC_ROUTES | OPTION_LIST      , 0x79 }, /* DHCP_STATIC_ROUTES */
+#if ENABLE_FEATURE_UDHCP_8021Q
+       { OPTION_U16                              , 0x84 }, /* DHCP_VLAN_ID       */
+       { OPTION_U8                               , 0x85 }, /* DHCP_VLAN_PRIORITY */
+#endif
+       { OPTION_STRING                           , 0xd1 }, /* DHCP_PXE_CONF_FILE */
+       { OPTION_6RD                              , 0xd4 }, /* DHCP_6RD           */
+       { OPTION_STATIC_ROUTES | OPTION_LIST      , 0xf9 }, /* DHCP_MS_STATIC_ROUTES */
+       { OPTION_STRING                           , 0xfc }, /* DHCP_WPAD          */
+
+       /* Options below have no match in dhcp_option_strings[],
+        * are not passed to dhcpc scripts, and cannot be specified
+        * with "option XXX YYY" syntax in dhcpd config file.
+        * These entries are only used internally by udhcp[cd]
+        * to correctly encode options into packets.
+        */
+
+       { OPTION_IP                               , 0x32 }, /* DHCP_REQUESTED_IP  */
+       { OPTION_U8                               , 0x35 }, /* DHCP_MESSAGE_TYPE  */
+       { OPTION_U16                              , 0x39 }, /* DHCP_MAX_SIZE      */
+//looks like these opts will work just fine even without these defs:
+//     { OPTION_STRING                           , 0x3c }, /* DHCP_VENDOR        */
+//     /* not really a string: */
+//     { OPTION_STRING                           , 0x3d }, /* DHCP_CLIENT_ID     */
+       { 0, 0 } /* zeroed terminating entry */
+};
 
+/* Used for converting options from incoming packets to env variables
+ * for udhcpc stript, and for setting options for udhcpd via
+ * "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
+ */
+/* Must match dhcp_optflags[] order */
+const char dhcp_option_strings[] ALIGN1 =
+       "subnet" "\0"      /* DHCP_SUBNET         */
+       "timezone" "\0"    /* DHCP_TIME_OFFSET    */
+       "router" "\0"      /* DHCP_ROUTER         */
+//     "timesrv" "\0"     /* DHCP_TIME_SERVER    */
+//     "namesrv" "\0"     /* DHCP_NAME_SERVER    */
+       "dns" "\0"         /* DHCP_DNS_SERVER     */
+//     "logsrv" "\0"      /* DHCP_LOG_SERVER     */
+//     "cookiesrv" "\0"   /* DHCP_COOKIE_SERVER  */
+       "lprsrv" "\0"      /* DHCP_LPR_SERVER     */
+       "hostname" "\0"    /* DHCP_HOST_NAME      */
+       "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
+       "domain" "\0"      /* DHCP_DOMAIN_NAME    */
+       "swapsrv" "\0"     /* DHCP_SWAP_SERVER    */
+       "rootpath" "\0"    /* DHCP_ROOT_PATH      */
+       "ipttl" "\0"       /* DHCP_IP_TTL         */
+       "mtu" "\0"         /* DHCP_MTU            */
+       "broadcast" "\0"   /* DHCP_BROADCAST      */
+       "routes" "\0"      /* DHCP_ROUTES         */
+       "nisdomain" "\0"   /* DHCP_NIS_DOMAIN     */
+       "nissrv" "\0"      /* DHCP_NIS_SERVER     */
+       "ntpsrv" "\0"      /* DHCP_NTP_SERVER     */
+       "wins" "\0"        /* DHCP_WINS_SERVER    */
+       "lease" "\0"       /* DHCP_LEASE_TIME     */
+       "serverid" "\0"    /* DHCP_SERVER_ID      */
+       "message" "\0"     /* DHCP_ERR_MESSAGE    */
+       "tftp" "\0"        /* DHCP_TFTP_SERVER_NAME */
+       "bootfile" "\0"    /* DHCP_BOOT_FILE      */
+//     "userclass" "\0"   /* DHCP_USER_CLASS     */
+#if ENABLE_FEATURE_UDHCP_RFC3397
+       "search" "\0"      /* DHCP_DOMAIN_SEARCH  */
+// doesn't work in udhcpd.conf since OPTION_SIP_SERVERS
+// is not handled yet by "string->option" conversion code:
+       "sipsrv" "\0"      /* DHCP_SIP_SERVERS    */
+#endif
+       "staticroutes" "\0"/* DHCP_STATIC_ROUTES  */
+#if ENABLE_FEATURE_UDHCP_8021Q
+       "vlanid" "\0"      /* DHCP_VLAN_ID        */
+       "vlanpriority" "\0"/* DHCP_VLAN_PRIORITY  */
+#endif
+       "pxeconffile" "\0" /* DHCP_PXE_CONF_FILE  */
+       "ip6rd" "\0"       /* DHCP_6RD            */
+       "msstaticroutes""\0"/* DHCP_MS_STATIC_ROUTES */
+       "wpad" "\0"        /* DHCP_WPAD           */
+       ;
+
+/* Lengths of the option types in binary form.
+ * Used by:
+ * udhcp_str2optset: to determine how many bytes to allocate.
+ * xmalloc_optname_optval: to estimate string length
+ * from binary option length: (option[LEN] / dhcp_option_lengths[opt_type])
+ * is the number of elements, multiply in by one element's string width
+ * (len_of_option_as_string[opt_type]) and you know how wide string you need.
+ */
+const uint8_t dhcp_option_lengths[] ALIGN1 = {
+       [OPTION_IP] =      4,
+       [OPTION_IP_PAIR] = 8,
+//     [OPTION_BOOLEAN] = 1,
+       [OPTION_STRING] =  1,  /* ignored by udhcp_str2optset */
+       [OPTION_STRING_HOST] = 1,  /* ignored by udhcp_str2optset */
+#if ENABLE_FEATURE_UDHCP_RFC3397
+       [OPTION_DNS_STRING] = 1,  /* ignored by both udhcp_str2optset and xmalloc_optname_optval */
+       [OPTION_SIP_SERVERS] = 1,
+#endif
+       [OPTION_U8] =      1,
+       [OPTION_U16] =     2,
+//     [OPTION_S16] =     2,
+       [OPTION_U32] =     4,
+       [OPTION_S32] =     4,
+       /* Just like OPTION_STRING, we use minimum length here */
+       [OPTION_STATIC_ROUTES] = 5,
+       [OPTION_6RD] =    22,  /* ignored by udhcp_str2optset */
+};
+
+
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
+static void log_option(const char *pfx, const uint8_t *opt)
+{
+       if (dhcp_verbose >= 2) {
+               char buf[256 * 2 + 2];
+               *bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
+               bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
+       }
+}
+#else
+# define log_option(pfx, opt) ((void)0)
+#endif
 
-long uptime(void)
+unsigned FAST_FUNC udhcp_option_idx(const char *name)
 {
-       struct sysinfo info;
-       sysinfo(&info);
-       return info.uptime;
+       int n = index_in_strings(dhcp_option_strings, name);
+       if (n >= 0)
+               return n;
+
+       {
+               char buf[sizeof(dhcp_option_strings)];
+               char *d = buf;
+               const char *s = dhcp_option_strings;
+               while (s < dhcp_option_strings + sizeof(dhcp_option_strings) - 2) {
+                       *d++ = (*s == '\0' ? ' ' : *s);
+                       s++;
+               }
+               *d = '\0';
+               bb_error_msg_and_die("unknown option '%s', known options: %s", name, buf);
+       }
 }
 
+/* Get an option with bounds checking (warning, result is not aligned) */
+uint8_t* FAST_FUNC udhcp_get_option(struct dhcp_packet *packet, int code)
+{
+       uint8_t *optionptr;
+       int len;
+       int rem;
+       int overload = 0;
+       enum {
+               FILE_FIELD101  = FILE_FIELD  * 0x101,
+               SNAME_FIELD101 = SNAME_FIELD * 0x101,
+       };
+
+       /* option bytes: [code][len][data1][data2]..[dataLEN] */
+       optionptr = packet->options;
+       rem = sizeof(packet->options);
+       while (1) {
+               if (rem <= 0) {
+                       bb_error_msg("bad packet, malformed option field");
+                       return NULL;
+               }
+               if (optionptr[OPT_CODE] == DHCP_PADDING) {
+                       rem--;
+                       optionptr++;
+                       continue;
+               }
+               if (optionptr[OPT_CODE] == DHCP_END) {
+                       if ((overload & FILE_FIELD101) == FILE_FIELD) {
+                               /* can use packet->file, and didn't look at it yet */
+                               overload |= FILE_FIELD101; /* "we looked at it" */
+                               optionptr = packet->file;
+                               rem = sizeof(packet->file);
+                               continue;
+                       }
+                       if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
+                               /* can use packet->sname, and didn't look at it yet */
+                               overload |= SNAME_FIELD101; /* "we looked at it" */
+                               optionptr = packet->sname;
+                               rem = sizeof(packet->sname);
+                               continue;
+                       }
+                       break;
+               }
+               len = 2 + optionptr[OPT_LEN];
+               rem -= len;
+               if (rem < 0)
+                       continue; /* complain and return NULL */
+
+               if (optionptr[OPT_CODE] == code) {
+                       log_option("Option found", optionptr);
+                       return optionptr + OPT_DATA;
+               }
 
-static const char *saved_pidfile;
+               if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
+                       overload |= optionptr[OPT_DATA];
+                       /* fall through */
+               }
+               optionptr += len;
+       }
 
-static void pidfile_delete(void)
+       /* log3 because udhcpc uses it a lot - very noisy */
+       log3("Option 0x%02x not found", code);
+       return NULL;
+}
+
+/* Return the position of the 'end' option (no bounds checking) */
+int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 {
-       if (saved_pidfile)
-               unlink(saved_pidfile);
+       int i = 0;
+
+       while (optionptr[i] != DHCP_END) {
+               if (optionptr[i] != DHCP_PADDING)
+                       i += optionptr[i + OPT_LEN] + OPT_DATA-1;
+               i++;
+       }
+       return i;
 }
 
-static int pidfile_acquire(const char *pidfile)
+/* Add an option (supplied in binary form) to the options.
+ * Option format: [code][len][data1][data2]..[dataLEN]
+ */
+void FAST_FUNC udhcp_add_binary_option(struct dhcp_packet *packet, uint8_t *addopt)
 {
-       int pid_fd;
-       if (!pidfile) return -1;
+       unsigned len;
+       uint8_t *optionptr = packet->options;
+       unsigned end = udhcp_end_option(optionptr);
 
-       pid_fd = open(pidfile, O_CREAT|O_WRONLY|O_TRUNC, 0644);
-       if (pid_fd < 0) {
-               bb_perror_msg("cannot open pidfile %s", pidfile);
-       } else {
-               /* lockf(pid_fd, F_LOCK, 0); */
-               if (!saved_pidfile)
-                       atexit(pidfile_delete);
-               saved_pidfile = pidfile;
+       len = OPT_DATA + addopt[OPT_LEN];
+       /* end position + (option code/length + addopt length) + end option */
+       if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
+//TODO: learn how to use overflow option if we exhaust packet->options[]
+               bb_error_msg("option 0x%02x did not fit into the packet",
+                               addopt[OPT_CODE]);
+               return;
+       }
+       log_option("Adding option", addopt);
+       memcpy(optionptr + end, addopt, len);
+       optionptr[end + len] = DHCP_END;
+}
+
+/* Add an one to four byte option to a packet */
+void FAST_FUNC udhcp_add_simple_option(struct dhcp_packet *packet, uint8_t code, uint32_t data)
+{
+       const struct dhcp_optflag *dh;
+
+       for (dh = dhcp_optflags; dh->code; dh++) {
+               if (dh->code == code) {
+                       uint8_t option[6], len;
+
+                       option[OPT_CODE] = code;
+                       len = dhcp_option_lengths[dh->flags & OPTION_TYPE_MASK];
+                       option[OPT_LEN] = len;
+                       if (BB_BIG_ENDIAN)
+                               data <<= 8 * (4 - len);
+                       /* Assignment is unaligned! */
+                       move_to_unaligned32(&option[OPT_DATA], data);
+                       udhcp_add_binary_option(packet, option);
+                       return;
+               }
        }
 
-       return pid_fd;
+       bb_error_msg("can't add option 0x%02x", code);
+}
+
+/* Find option 'code' in opt_list */
+struct option_set* FAST_FUNC udhcp_find_option(struct option_set *opt_list, uint8_t code)
+{
+       while (opt_list && opt_list->data[OPT_CODE] < code)
+               opt_list = opt_list->next;
+
+       if (opt_list && opt_list->data[OPT_CODE] == code)
+               return opt_list;
+       return NULL;
 }
 
-static void pidfile_write_release(int pid_fd)
+/* Parse string to IP in network order */
+int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
 {
-       if (pid_fd < 0) return;
+       len_and_sockaddr *lsa;
 
-       fdprintf(pid_fd, "%d\n", getpid());
-       /* lockf(pid_fd, F_UNLCK, 0); */
-       close(pid_fd);
+       lsa = host_and_af2sockaddr(str, 0, AF_INET);
+       if (!lsa)
+               return 0;
+       /* arg maybe unaligned */
+       move_to_unaligned32((uint32_t*)arg, lsa->u.sin.sin_addr.s_addr);
+       free(lsa);
+       return 1;
 }
 
+/* udhcp_str2optset:
+ * Parse string option representation to binary form and add it to opt_list.
+ * Called to parse "udhcpc -x OPTNAME:OPTVAL"
+ * and to parse udhcpd.conf's "opt OPTNAME OPTVAL" directives.
+ */
+/* helper for the helper */
+static char *allocate_tempopt_if_needed(
+               const struct dhcp_optflag *optflag,
+               char *buffer,
+               int *length_p)
+{
+       char *allocated = NULL;
+       if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_BIN) {
+               const char *end;
+               allocated = xstrdup(buffer); /* more than enough */
+               end = hex2bin(allocated, buffer, 255);
+               if (errno)
+                       bb_error_msg_and_die("malformed hex string '%s'", buffer);
+               *length_p = end - allocated;
+       }
+       return allocated;
+}
+/* helper: add an option to the opt_list */
+static NOINLINE void attach_option(
+               struct option_set **opt_list,
+               const struct dhcp_optflag *optflag,
+               char *buffer,
+               int length)
+{
+       struct option_set *existing;
+       char *allocated;
+
+       allocated = allocate_tempopt_if_needed(optflag, buffer, &length);
+#if ENABLE_FEATURE_UDHCP_RFC3397
+       if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_DNS_STRING) {
+               /* reuse buffer and length for RFC1035-formatted string */
+               allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
+       }
+#endif
+
+       existing = udhcp_find_option(*opt_list, optflag->code);
+       if (!existing) {
+               struct option_set *new, **curr;
+
+               /* make a new option */
+               log2("Attaching option %02x to list", optflag->code);
+               new = xmalloc(sizeof(*new));
+               new->data = xmalloc(length + OPT_DATA);
+               new->data[OPT_CODE] = optflag->code;
+               new->data[OPT_LEN] = length;
+               memcpy(new->data + OPT_DATA, (allocated ? allocated : buffer), length);
+
+               curr = opt_list;
+               while (*curr && (*curr)->data[OPT_CODE] < optflag->code)
+                       curr = &(*curr)->next;
+
+               new->next = *curr;
+               *curr = new;
+               goto ret;
+       }
+
+       if (optflag->flags & OPTION_LIST) {
+               unsigned old_len;
+
+               /* add it to an existing option */
+               log2("Attaching option %02x to existing member of list", optflag->code);
+               old_len = existing->data[OPT_LEN];
+               if (old_len + length < 255) {
+                       /* actually 255 is ok too, but adding a space can overlow it */
+
+                       existing->data = xrealloc(existing->data, OPT_DATA + 1 + old_len + length);
+                       if ((optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING
+                        || (optflag->flags & OPTION_TYPE_MASK) == OPTION_STRING_HOST
+                       ) {
+                               /* add space separator between STRING options in a list */
+                               existing->data[OPT_DATA + old_len] = ' ';
+                               old_len++;
+                       }
+                       memcpy(existing->data + OPT_DATA + old_len, (allocated ? allocated : buffer), length);
+                       existing->data[OPT_LEN] = old_len + length;
+               } /* else, ignore the data, we could put this in a second option in the future */
+       } /* else, ignore the new data */
 
-void udhcp_make_pidfile(const char *pidfile)
+ ret:
+       free(allocated);
+}
+
+int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
 {
-       int pid_fd;
+       struct option_set **opt_list = arg;
+       char *opt, *val;
+       char *str;
+       const struct dhcp_optflag *optflag;
+       struct dhcp_optflag bin_optflag;
+       unsigned optcode;
+       int retval, length;
+       /* IP_PAIR needs 8 bytes, STATIC_ROUTES needs 9 max */
+       char buffer[9] ALIGNED(4);
+       uint16_t *result_u16 = (uint16_t *) buffer;
+       uint32_t *result_u32 = (uint32_t *) buffer;
 
-       /* Make sure fd 0,1,2 are open */
-       bb_sanitize_stdio();
+       /* Cheat, the only *const* str possible is "" */
+       str = (char *) const_str;
+       opt = strtok(str, " \t=");
+       if (!opt)
+               return 0;
 
-       /* Equivalent of doing a fflush after every \n */
-       setlinebuf(stdout);
+       optcode = bb_strtou(opt, NULL, 0);
+       if (!errno && optcode < 255) {
+               /* Raw (numeric) option code */
+               bin_optflag.flags = OPTION_BIN;
+               bin_optflag.code = optcode;
+               optflag = &bin_optflag;
+       } else {
+               optflag = &dhcp_optflags[udhcp_option_idx(opt)];
+       }
 
-       /* Create pidfile */
-       pid_fd = pidfile_acquire(pidfile);
-       pidfile_write_release(pid_fd);
+       retval = 0;
+       do {
+               val = strtok(NULL, ", \t");
+               if (!val)
+                       break;
+               length = dhcp_option_lengths[optflag->flags & OPTION_TYPE_MASK];
+               retval = 0;
+               opt = buffer; /* new meaning for variable opt */
+               switch (optflag->flags & OPTION_TYPE_MASK) {
+               case OPTION_IP:
+                       retval = udhcp_str2nip(val, buffer);
+                       break;
+               case OPTION_IP_PAIR:
+                       retval = udhcp_str2nip(val, buffer);
+                       val = strtok(NULL, ", \t/-");
+                       if (!val)
+                               retval = 0;
+                       if (retval)
+                               retval = udhcp_str2nip(val, buffer + 4);
+                       break;
+               case OPTION_STRING:
+               case OPTION_STRING_HOST:
+#if ENABLE_FEATURE_UDHCP_RFC3397
+               case OPTION_DNS_STRING:
+#endif
+                       length = strnlen(val, 254);
+                       if (length > 0) {
+                               opt = val;
+                               retval = 1;
+                       }
+                       break;
+//             case OPTION_BOOLEAN: {
+//                     static const char no_yes[] ALIGN1 = "no\0yes\0";
+//                     buffer[0] = retval = index_in_strings(no_yes, val);
+//                     retval++; /* 0 - bad; 1: "no" 2: "yes" */
+//                     break;
+//             }
+               case OPTION_U8:
+                       buffer[0] = bb_strtou32(val, NULL, 0);
+                       retval = (errno == 0);
+                       break;
+               /* htonX are macros in older libc's, using temp var
+                * in code below for safety */
+               /* TODO: use bb_strtoX? */
+               case OPTION_U16: {
+                       uint32_t tmp = bb_strtou32(val, NULL, 0);
+                       *result_u16 = htons(tmp);
+                       retval = (errno == 0 /*&& tmp < 0x10000*/);
+                       break;
+               }
+//             case OPTION_S16: {
+//                     long tmp = bb_strtoi32(val, NULL, 0);
+//                     *result_u16 = htons(tmp);
+//                     retval = (errno == 0);
+//                     break;
+//             }
+               case OPTION_U32: {
+                       uint32_t tmp = bb_strtou32(val, NULL, 0);
+                       *result_u32 = htonl(tmp);
+                       retval = (errno == 0);
+                       break;
+               }
+               case OPTION_S32: {
+                       int32_t tmp = bb_strtoi32(val, NULL, 0);
+                       *result_u32 = htonl(tmp);
+                       retval = (errno == 0);
+                       break;
+               }
+               case OPTION_STATIC_ROUTES: {
+                       /* Input: "a.b.c.d/m" */
+                       /* Output: mask(1 byte),pfx(0-4 bytes),gw(4 bytes) */
+                       unsigned mask;
+                       char *slash = strchr(val, '/');
+                       if (slash) {
+                               *slash = '\0';
+                               retval = udhcp_str2nip(val, buffer + 1);
+                               buffer[0] = mask = bb_strtou(slash + 1, NULL, 10);
+                               val = strtok(NULL, ", \t/-");
+                               if (!val || mask > 32 || errno)
+                                       retval = 0;
+                               if (retval) {
+                                       length = ((mask + 7) >> 3) + 5;
+                                       retval = udhcp_str2nip(val, buffer + (length - 4));
+                               }
+                       }
+                       break;
+               }
+               case OPTION_BIN: /* handled in attach_option() */
+                       opt = val;
+                       retval = 1;
+               default:
+                       break;
+               }
+               if (retval)
+                       attach_option(opt_list, optflag, opt, length);
+       } while (retval && (optflag->flags & OPTION_LIST));
 
-       bb_info_msg("%s (v%s) started", applet_name, BB_VER);
+       return retval;
+}
+
+/* note: ip is a pointer to an IPv6 in network order, possibly misaliged */
+int FAST_FUNC sprint_nip6(char *dest, /*const char *pre,*/ const uint8_t *ip)
+{
+       char hexstrbuf[16 * 2];
+       bin2hex(hexstrbuf, (void*)ip, 16);
+       return sprintf(dest, /* "%s" */
+               "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
+               /* pre, */
+               hexstrbuf + 0 * 4,
+               hexstrbuf + 1 * 4,
+               hexstrbuf + 2 * 4,
+               hexstrbuf + 3 * 4,
+               hexstrbuf + 4 * 4,
+               hexstrbuf + 5 * 4,
+               hexstrbuf + 6 * 4,
+               hexstrbuf + 7 * 4
+       );
 }