dhcpd: remember and record hostnames; optimize get_option

dumpleases: show hostnames

function                                             old     new   delta
add_lease                                            230     292     +62
send_offer                                           403     421     +18
send_ACK                                             232     249     +17
read_leases                                          249     258      +9
dumpleases_main                                      604     609      +5
nobody_responds_to_arp                                84      86      +2
udhcp_end_option                                      32      30      -2
udhcp_get_option                                     222     171     -51
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/2 up/down: 113/-53)            Total: 60 bytes

1 files changed, 7 insertions, 3 deletions

diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h
index 02e392aaf..b4e180882 100644
--- a/networking/udhcp/dhcpd.h
+++ b/networking/udhcp/dhcpd.h
@@ -74,8 +74,6 @@ struct server_config_t {
 #define SERVER_PORT 67
 #endif
 
-extern struct dhcpOfferedAddr *leases;
-
 
 /*** leases.h ***/
 
@@ -92,9 +90,15 @@ struct dhcpOfferedAddr {
          * and optionally adjusted (current time subtracted)
          * if server_config.remaining = 1 */
         leasetime_t expires;
+        uint8_t hostname[20]; /* (size is a multiply of 4) */
 };
 
-struct dhcpOfferedAddr *add_lease(const uint8_t *chaddr, uint32_t yiaddr, leasetime_t leasetime) FAST_FUNC;
+extern struct dhcpOfferedAddr *leases;
+
+struct dhcpOfferedAddr *add_lease(
+                const uint8_t *chaddr, uint32_t yiaddr,
+                leasetime_t leasetime, uint8_t *hostname
+                ) FAST_FUNC;
 int lease_expired(struct dhcpOfferedAddr *lease) FAST_FUNC;
 struct dhcpOfferedAddr *find_lease_by_chaddr(const uint8_t *chaddr) FAST_FUNC;
 struct dhcpOfferedAddr *find_lease_by_yiaddr(uint32_t yiaddr) FAST_FUNC;