dhcp: covert DHCP_OPTION_IDX_* from defines to enum (mainly to ease offset calculation)
diff --git a/src/core/ipv4/dhcp.c b/src/core/ipv4/dhcp.c
index abff34d..eaae34d 100644
--- a/src/core/ipv4/dhcp.c
+++ b/src/core/ipv4/dhcp.c
@@ -108,21 +108,23 @@
* This might be moved into the struct dhcp (not necessarily since
* lwIP is single-threaded and the array is only used while in recv
* callback). */
-#define DHCP_OPTION_IDX_OVERLOAD 0
-#define DHCP_OPTION_IDX_MSG_TYPE 1
-#define DHCP_OPTION_IDX_SERVER_ID 2
-#define DHCP_OPTION_IDX_LEASE_TIME 3
-#define DHCP_OPTION_IDX_T1 4
-#define DHCP_OPTION_IDX_T2 5
-#define DHCP_OPTION_IDX_SUBNET_MASK 6
-#define DHCP_OPTION_IDX_ROUTER 7
-#define DHCP_OPTION_IDX_DNS_SERVER 8
+enum dhcp_option_idx {
+ DHCP_OPTION_IDX_OVERLOAD = 0,
+ DHCP_OPTION_IDX_MSG_TYPE,
+ DHCP_OPTION_IDX_SERVER_ID,
+ DHCP_OPTION_IDX_LEASE_TIME,
+ DHCP_OPTION_IDX_T1,
+ DHCP_OPTION_IDX_T2,
+ DHCP_OPTION_IDX_SUBNET_MASK,
+ DHCP_OPTION_IDX_ROUTER,
+ DHCP_OPTION_IDX_DNS_SERVER,
+ DHCP_OPTION_IDX_DNS_SERVER_LAST = DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS - 1,
#if LWIP_DHCP_GET_NTP_SRV
-#define DHCP_OPTION_IDX_NTP_SERVER (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS)
-#define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS)
-#else /* LWIP_DHCP_GET_NTP_SRV */
-#define DHCP_OPTION_IDX_MAX (DHCP_OPTION_IDX_DNS_SERVER + DNS_MAX_SERVERS)
+ DHCP_OPTION_IDX_NTP_SERVER,
+ DHCP_OPTION_IDX_NTP_SERVER_LAST = DHCP_OPTION_IDX_NTP_SERVER + LWIP_DHCP_MAX_NTP_SERVERS - 1,
#endif /* LWIP_DHCP_GET_NTP_SRV */
+ DHCP_OPTION_IDX_MAX
+};
/** Holds the decoded option values, only valid while in dhcp_recv.
@todo: move this into struct dhcp? */
