/*
* options.c -- DHCP server option packet tools
* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "common.h"
#include "options.h"
-/* supported options are easily added here */
-struct dhcp_option dhcp_options[] = {
- /* name[10] flags code */
- {"subnet", OPTION_IP | OPTION_REQ, 0x01},
- {"timezone", OPTION_S32, 0x02},
- {"router", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03},
- {"timesvr", OPTION_IP | OPTION_LIST, 0x04},
- {"namesvr", OPTION_IP | OPTION_LIST, 0x05},
- {"dns", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06},
- {"logsvr", OPTION_IP | OPTION_LIST, 0x07},
- {"cookiesvr", OPTION_IP | OPTION_LIST, 0x08},
- {"lprsvr", OPTION_IP | OPTION_LIST, 0x09},
- {"hostname", OPTION_STRING | OPTION_REQ, 0x0c},
- {"bootsize", OPTION_U16, 0x0d},
- {"domain", OPTION_STRING | OPTION_REQ, 0x0f},
- {"swapsvr", OPTION_IP, 0x10},
- {"rootpath", OPTION_STRING, 0x11},
- {"ipttl", OPTION_U8, 0x17},
- {"mtu", OPTION_U16, 0x1a},
- {"broadcast", OPTION_IP | OPTION_REQ, 0x1c},
- {"nisdomain", OPTION_STRING | OPTION_REQ, 0x28},
- {"nissrv", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x29},
- {"ntpsrv", OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a},
- {"wins", OPTION_IP | OPTION_LIST, 0x2c},
- {"requestip", OPTION_IP, 0x32},
- {"lease", OPTION_U32, 0x33},
- {"dhcptype", OPTION_U8, 0x35},
- {"serverid", OPTION_IP, 0x36},
- {"message", OPTION_STRING, 0x38},
- {"vendorclass", OPTION_STRING, 0x3C},
- {"clientid", OPTION_STRING, 0x3D},
- {"tftp", OPTION_STRING, 0x42},
- {"bootfile", OPTION_STRING, 0x43},
- {"userclass", OPTION_STRING, 0x4D},
- {"", 0x00, 0x00}
+/* Supported options are easily added here */
+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_LIST | 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 }, /* nisdomain */
+ { OPTION_IP | OPTION_LIST , 0x29 }, /* nissrv */
+ { OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER */
+ { OPTION_IP | OPTION_LIST , 0x2c }, /* DHCP_WINS_SERVER */
+ { OPTION_IP , 0x32 }, /* DHCP_REQUESTED_IP */
+ { OPTION_U32 , 0x33 }, /* DHCP_LEASE_TIME */
+ { OPTION_U8 , 0x35 }, /* dhcptype */
+ { OPTION_IP , 0x36 }, /* DHCP_SERVER_ID */
+ { OPTION_STRING , 0x38 }, /* DHCP_MESSAGE */
+ { OPTION_STRING , 0x3C }, /* DHCP_VENDOR */
+ { OPTION_STRING , 0x3D }, /* DHCP_CLIENT_ID */
+ { OPTION_STRING , 0x42 }, /* tftp */
+ { OPTION_STRING , 0x43 }, /* bootfile */
+ { OPTION_STRING , 0x4D }, /* userclass */
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ { OPTION_STR1035 | OPTION_LIST , 0x77 }, /* search */
+#endif
+ /* MSIE's "Web Proxy Autodiscovery Protocol" support */
+ { OPTION_STRING , 0xfc }, /* 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. */
+
+ { OPTION_U16 , 0x39 }, /* DHCP_MAX_SIZE */
+ { } /* zeroed terminating entry */
};
+/* Used for converting options from incoming packets to env variables
+ * for udhcpc stript */
+/* 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" /* */
+ "nissrv" "\0" /* */
+ "ntpsrv" "\0" /* DHCP_NTP_SERVER */
+ "wins" "\0" /* DHCP_WINS_SERVER */
+ "requestip" "\0" /* DHCP_REQUESTED_IP */
+ "lease" "\0" /* DHCP_LEASE_TIME */
+ "dhcptype" "\0" /* */
+ "serverid" "\0" /* DHCP_SERVER_ID */
+ "message" "\0" /* DHCP_MESSAGE */
+ "vendorclass" "\0" /* DHCP_VENDOR */
+ "clientid" "\0" /* DHCP_CLIENT_ID */
+ "tftp" "\0"
+ "bootfile" "\0"
+ "userclass" "\0"
+#if ENABLE_FEATURE_UDHCP_RFC3397
+ "search" "\0"
+#endif
+ /* MSIE's "Web Proxy Autodiscovery Protocol" support */
+ "wpad" "\0"
+ ;
+
+
/* Lengths of the different option types */
-int option_lengths[] = {
- [OPTION_IP] = 4,
- [OPTION_IP_PAIR] = 8,
- [OPTION_BOOLEAN] = 1,
- [OPTION_STRING] = 1,
- [OPTION_U8] = 1,
- [OPTION_U16] = 2,
- [OPTION_S16] = 2,
- [OPTION_U32] = 4,
- [OPTION_S32] = 4
+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
};
/* get an option with bounds checking (warning, not aligned). */
-uint8_t *get_option(struct dhcpMessage *packet, int code)
+uint8_t* FAST_FUNC get_option(struct dhcpMessage *packet, int code)
{
int i, length;
uint8_t *optionptr;
- int over = 0, done = 0, curr = OPTION_FIELD;
+ int over = 0;
+ int curr = OPTION_FIELD;
optionptr = packet->options;
i = 0;
- length = 308;
- while (!done) {
+ length = sizeof(packet->options);
+ while (1) {
if (i >= length) {
bb_error_msg("bogus packet, option fields too long");
return NULL;
i += optionptr[OPT_LEN] + 2;
break;
case DHCP_END:
- if (curr == OPTION_FIELD && over & FILE_FIELD) {
+ if (curr == OPTION_FIELD && (over & FILE_FIELD)) {
optionptr = packet->file;
i = 0;
- length = 128;
+ length = sizeof(packet->file);
curr = FILE_FIELD;
- } else if (curr == FILE_FIELD && over & SNAME_FIELD) {
+ } else if (curr == FILE_FIELD && (over & SNAME_FIELD)) {
optionptr = packet->sname;
i = 0;
- length = 64;
+ length = sizeof(packet->sname);
curr = SNAME_FIELD;
- } else done = 1;
+ } else
+ return NULL;
break;
default:
i += optionptr[OPT_LEN + i] + 2;
/* return the position of the 'end' option (no bounds checking) */
-int end_option(uint8_t *optionptr)
+int FAST_FUNC end_option(uint8_t *optionptr)
{
int i = 0;
while (optionptr[i] != DHCP_END) {
- if (optionptr[i] == DHCP_PADDING) i++;
- else i += optionptr[i + OPT_LEN] + 2;
+ if (optionptr[i] == DHCP_PADDING)
+ i++;
+ else
+ i += optionptr[i + OPT_LEN] + 2;
}
return i;
}
/* add an option string to the options (an option string contains an option code,
* length, then data) */
-int add_option_string(uint8_t *optionptr, uint8_t *string)
+int FAST_FUNC add_option_string(uint8_t *optionptr, uint8_t *string)
{
int end = end_option(optionptr);
/* end position + string length + option code/length + end option */
- if (end + string[OPT_LEN] + 2 + 1 >= 308) {
+ if (end + string[OPT_LEN] + 2 + 1 >= DHCP_OPTIONS_BUFSIZE) {
bb_error_msg("option 0x%02x did not fit into the packet",
string[OPT_CODE]);
return 0;
/* add a one to four byte option to a packet */
-int add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
+int FAST_FUNC add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
{
- struct dhcp_option *dh;
+ const struct dhcp_option *dh;
- for (dh=dhcp_options; dh->code; dh++) {
+ for (dh = dhcp_options; dh->code; dh++) {
if (dh->code == code) {
uint8_t option[6], len;
option[OPT_CODE] = code;
- len = option_lengths[dh->flags & TYPE_MASK];
+ len = dhcp_option_lengths[dh->flags & TYPE_MASK];
option[OPT_LEN] = len;
- if (BB_BIG_ENDIAN) data <<= 8 * (4 - len);
- /* This memcpy is for broken processors which can't
+ if (BB_BIG_ENDIAN)
+ data <<= 8 * (4 - len);
+ /* This memcpy is for processors which can't
* handle a simple unaligned 32-bit assignment */
memcpy(&option[OPT_DATA], &data, 4);
return add_option_string(optionptr, option);