udhcp: MAC_BCAST_ADDR and blank_chaddr are in fact constant, move to rodata.

a few global variables reduced to smallints
function                                             old     new   delta
add_lease                                             75     227    +152
static.blank_chaddr                                    -      16     +16
MAC_BCAST_ADDR                                         -       6      +6
sockfd                                                 4       8      +4
udhcp_run_script                                    1153    1155      +2
state                                                  8       5      -3
listen_mode                                            4       1      -3
perform_release                                      152     148      -4
fd                                                     8       4      -4
blank_chaddr                                          16       -     -16
udhcpc_main                                         2518    2497     -21
.rodata                                           131864  131832     -32
oldest_expired_lease                                  61       -     -61
clear_lease                                          127       -    -127
------------------------------------------------------------------------------
(add/remove: 2/3 grow/shrink: 3/6 up/down: 180/-271)          Total: -91 bytes

1 files changed, 2 insertions, 81 deletions

diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h
index 40959e4ae..7c4fe695a 100644
--- a/networking/udhcp/dhcpd.h
+++ b/networking/udhcp/dhcpd.h
@@ -14,81 +14,6 @@
 /* where to find the DHCP server configuration file */
 #define DHCPD_CONF_FILE         "/etc/udhcpd.conf"
 
-/*****************************************************************/
-/* Do not modify below here unless you know what you are doing!! */
-/*****************************************************************/
-
-/* DHCP protocol -- see RFC 2131 */
-#define SERVER_PORT             67
-#define CLIENT_PORT             68
-
-#define DHCP_MAGIC              0x63825363
-
-/* DHCP option codes (partial list) */
-#define DHCP_PADDING            0x00
-#define DHCP_SUBNET             0x01
-#define DHCP_TIME_OFFSET        0x02
-#define DHCP_ROUTER             0x03
-#define DHCP_TIME_SERVER        0x04
-#define DHCP_NAME_SERVER        0x05
-#define DHCP_DNS_SERVER         0x06
-#define DHCP_LOG_SERVER         0x07
-#define DHCP_COOKIE_SERVER      0x08
-#define DHCP_LPR_SERVER         0x09
-#define DHCP_HOST_NAME          0x0c
-#define DHCP_BOOT_SIZE          0x0d
-#define DHCP_DOMAIN_NAME        0x0f
-#define DHCP_SWAP_SERVER        0x10
-#define DHCP_ROOT_PATH          0x11
-#define DHCP_IP_TTL             0x17
-#define DHCP_MTU                0x1a
-#define DHCP_BROADCAST          0x1c
-#define DHCP_NTP_SERVER         0x2a
-#define DHCP_WINS_SERVER        0x2c
-#define DHCP_REQUESTED_IP       0x32
-#define DHCP_LEASE_TIME         0x33
-#define DHCP_OPTION_OVER        0x34
-#define DHCP_MESSAGE_TYPE       0x35
-#define DHCP_SERVER_ID          0x36
-#define DHCP_PARAM_REQ          0x37
-#define DHCP_MESSAGE            0x38
-#define DHCP_MAX_SIZE           0x39
-#define DHCP_T1                 0x3a
-#define DHCP_T2                 0x3b
-#define DHCP_VENDOR             0x3c
-#define DHCP_CLIENT_ID          0x3d
-#define DHCP_FQDN               0x51
-
-#define DHCP_END                0xFF
-
-
-#define BOOTREQUEST             1
-#define BOOTREPLY               2
-
-#define ETH_10MB                1
-#define ETH_10MB_LEN            6
-
-#define DHCPDISCOVER            1
-#define DHCPOFFER               2
-#define DHCPREQUEST             3
-#define DHCPDECLINE             4
-#define DHCPACK                 5
-#define DHCPNAK                 6
-#define DHCPRELEASE             7
-#define DHCPINFORM              8
-
-#define BROADCAST_FLAG          0x8000
-
-#define OPTION_FIELD            0
-#define FILE_FIELD              1
-#define SNAME_FIELD             2
-
-/* miscellaneous defines */
-#define MAC_BCAST_ADDR          (uint8_t *) "\xff\xff\xff\xff\xff\xff"
-#define OPT_CODE 0
-#define OPT_LEN 1
-#define OPT_DATA 2
-
 struct option_set {
         uint8_t *data;
         struct option_set *next;
@@ -140,13 +65,9 @@ struct dhcpOfferedAddr {
         uint32_t expires;       /* host order */
 };
 
-extern uint8_t blank_chaddr[];
-
-void clear_lease(uint8_t *chaddr, uint32_t yiaddr);
-struct dhcpOfferedAddr *add_lease(uint8_t *chaddr, uint32_t yiaddr, unsigned long lease);
+struct dhcpOfferedAddr *add_lease(const uint8_t *chaddr, uint32_t yiaddr, unsigned long lease);
 int lease_expired(struct dhcpOfferedAddr *lease);
-struct dhcpOfferedAddr *oldest_expired_lease(void);
-struct dhcpOfferedAddr *find_lease_by_chaddr(uint8_t *chaddr);
+struct dhcpOfferedAddr *find_lease_by_chaddr(const uint8_t *chaddr);
 struct dhcpOfferedAddr *find_lease_by_yiaddr(uint32_t yiaddr);
 uint32_t find_address(int check_expired);