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-rw-r--r--networking/udhcp/common.c454
1 files changed, 452 insertions, 2 deletions
diff --git a/networking/udhcp/common.c b/networking/udhcp/common.c
index 4de29f2..bc458ac 100644
--- a/networking/udhcp/common.c
+++ b/networking/udhcp/common.c
@@ -1,7 +1,8 @@
/* vi: set sw=4 ts=4: */
-/* common.c
+/*
+ * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "common.h"
@@ -12,3 +13,452 @@ unsigned dhcp_verbose;
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_option dhcp_options[] = {
+ /* 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 | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
+ { OPTION_U16 , 0x0d }, /* DHCP_BOOT_SIZE */
+ { OPTION_STRING | 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 */
+ { OPTION_IP | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST */
+ { OPTION_STRING , 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 , 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_STR1035 | OPTION_LIST , 0x77 }, /* DHCP_DOMAIN_SEARCH */
+#endif
+ { OPTION_STATIC_ROUTES , 0x79 }, /* DHCP_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 */
+ { OPTION_STRING , 0x3c }, /* DHCP_VENDOR */
+//FIXME: handling of this option is not exactly correct:
+ { 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_options[] 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 */
+ "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 */
+#endif
+// "staticroutes" is only used to set udhcpc environment, it doesn't work
+// in udhcpd.conf since OPTION_STATIC_ROUTES is not handled yet
+// by "string->option" conversion code:
+ "staticroutes" "\0"/* DHCP_STATIC_ROUTES */
+ "wpad" "\0" /* DHCP_WPAD */
+ ;
+
+/* Lengths of the different option types */
+const uint8_t dhcp_option_lengths[] ALIGN1 = {
+ [OPTION_IP] = 4,
+ [OPTION_IP_PAIR] = 8,
+// [OPTION_BOOLEAN] = 1,
+ [OPTION_STRING] = 1,
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ [OPTION_STR1035] = 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,
+};
+
+
+#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
+
+/* 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;
+ }
+
+ if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
+ overload |= optionptr[OPT_DATA];
+ /* fall through */
+ }
+ optionptr += len;
+ }
+
+ /* 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)
+{
+ int i = 0;
+
+ while (optionptr[i] != DHCP_END) {
+ if (optionptr[i] != DHCP_PADDING)
+ i += optionptr[i + OPT_LEN] + OPT_DATA-1;
+ i++;
+ }
+ return i;
+}
+
+/* Add an option (supplied in binary form) to the options.
+ * Option format: [code][len][data1][data2]..[dataLEN]
+ */
+void FAST_FUNC udhcp_add_binary_option(uint8_t *optionptr, uint8_t *addopt)
+{
+ unsigned len;
+ unsigned end = udhcp_end_option(optionptr);
+
+ /* end position + option code/length + addopt length + end option */
+ len = OPT_DATA + addopt[OPT_LEN];
+ if (end + len + 1 >= DHCP_OPTIONS_BUFSIZE) {
+ 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 a one to four byte option to a packet */
+void FAST_FUNC udhcp_add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
+{
+ const struct dhcp_option *dh;
+
+ for (dh = dhcp_options; 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(optionptr, option);
+ return;
+ }
+ }
+
+ bb_error_msg("can't add option 0x%02x", code);
+}
+
+/* Find option 'code' in opt_list */
+struct option_set* FAST_FUNC 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;
+}
+
+/* Parse string to IP in network order */
+int FAST_FUNC udhcp_str2nip(const char *str, void *arg)
+{
+ len_and_sockaddr *lsa;
+
+ lsa = host_and_af2sockaddr(str, 0, AF_INET);
+ if (!lsa)
+ return 0;
+ *(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
+ */
+/* helper: add an option to the opt_list */
+static NOINLINE void attach_option(
+ struct option_set **opt_list,
+ const struct dhcp_option *option,
+ char *buffer,
+ int length)
+{
+ struct option_set *existing, *new, **curr;
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ char *allocated = NULL;
+#endif
+
+ existing = find_option(*opt_list, option->code);
+ if (!existing) {
+ log2("Attaching option %02x to list", option->code);
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ if ((option->flags & OPTION_TYPE_MASK) == OPTION_STR1035) {
+ /* reuse buffer and length for RFC1035-formatted string */
+ allocated = buffer = (char *)dname_enc(NULL, 0, buffer, &length);
+ }
+#endif
+ /* make a new option */
+ new = xmalloc(sizeof(*new));
+ new->data = xmalloc(length + OPT_DATA);
+ new->data[OPT_CODE] = option->code;
+ new->data[OPT_LEN] = length;
+ memcpy(new->data + OPT_DATA, buffer, length);
+
+ curr = opt_list;
+ while (*curr && (*curr)->data[OPT_CODE] < option->code)
+ curr = &(*curr)->next;
+
+ new->next = *curr;
+ *curr = new;
+ goto ret;
+ }
+
+ if (option->flags & OPTION_LIST) {
+ unsigned old_len;
+
+ /* add it to an existing option */
+ log1("Attaching option %02x to existing member of list", option->code);
+ old_len = existing->data[OPT_LEN];
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ if ((option->flags & OPTION_TYPE_MASK) == OPTION_STR1035) {
+ /* reuse buffer and length for RFC1035-formatted string */
+ allocated = buffer = (char *)dname_enc(existing->data + OPT_DATA, old_len, buffer, &length);
+ }
+#endif
+ 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 ((option->flags & OPTION_TYPE_MASK) == OPTION_STRING) {
+ /* add space separator between STRING options in a list */
+ existing->data[OPT_DATA + old_len] = ' ';
+ old_len++;
+ }
+ memcpy(existing->data + OPT_DATA + old_len, 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 */
+
+ ret: ;
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ free(allocated);
+#endif
+}
+
+int FAST_FUNC udhcp_str2optset(const char *const_str, void *arg)
+{
+ struct option_set **opt_list = arg;
+ char *opt, *val, *endptr;
+ char *str;
+ const struct dhcp_option *option;
+ int retval, length, idx;
+ char buffer[8] ALIGNED(4);
+ uint16_t *result_u16 = (uint16_t *) buffer;
+ uint32_t *result_u32 = (uint32_t *) buffer;
+
+ /* Cheat, the only *const* str possible is "" */
+ str = (char *) const_str;
+ opt = strtok(str, " \t=");
+ if (!opt)
+ return 0;
+
+ idx = index_in_strings(dhcp_option_strings, opt); /* NB: was strcasecmp! */
+ if (idx < 0)
+ return 0;
+ option = &dhcp_options[idx];
+
+ retval = 0;
+ do {
+ val = strtok(NULL, ", \t");
+ if (!val)
+ break;
+ length = dhcp_option_lengths[option->flags & OPTION_TYPE_MASK];
+ retval = 0;
+ opt = buffer; /* new meaning for variable opt */
+ switch (option->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:
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ case OPTION_STR1035:
+#endif
+ length = strnlen(val, 254);
+ if (length > 0) {
+ opt = val;
+ retval = 1;
+ }
+ break;
+// case OPTION_BOOLEAN: {
+// static const char noyes[] ALIGN1 = "no\0yes\0";
+// buffer[0] = retval = index_in_strings(noyes, val);
+// retval++; /* 0 - bad; 1: "no" 2: "yes" */
+// break;
+// }
+ case OPTION_U8:
+ buffer[0] = strtoul(val, &endptr, 0);
+ retval = (endptr[0] == '\0');
+ break;
+ /* htonX are macros in older libc's, using temp var
+ * in code below for safety */
+ /* TODO: use bb_strtoX? */
+ case OPTION_U16: {
+ unsigned long tmp = strtoul(val, &endptr, 0);
+ *result_u16 = htons(tmp);
+ retval = (endptr[0] == '\0' /*&& tmp < 0x10000*/);
+ break;
+ }
+// case OPTION_S16: {
+// long tmp = strtol(val, &endptr, 0);
+// *result_u16 = htons(tmp);
+// retval = (endptr[0] == '\0');
+// break;
+// }
+ case OPTION_U32: {
+ unsigned long tmp = strtoul(val, &endptr, 0);
+ *result_u32 = htonl(tmp);
+ retval = (endptr[0] == '\0');
+ break;
+ }
+ case OPTION_S32: {
+ long tmp = strtol(val, &endptr, 0);
+ *result_u32 = htonl(tmp);
+ retval = (endptr[0] == '\0');
+ break;
+ }
+ default:
+ break;
+ }
+ if (retval)
+ attach_option(opt_list, option, opt, length);
+ } while (retval && option->flags & OPTION_LIST);
+
+ return retval;
+}