udhcpd: disable opton to have absolute lease times in lease file

 (that does not work with dumpleases)
dumpleases: fix -a option.
networking/udhcp/*: code shrink, more compact static leases struture,
 better comments, etc

function                                             old     new   delta
find_free_or_expired_address                           -     147    +147
nobody_responds_to_arp                                 -      84     +84
read_opt                                             781     830     +49
dumpleases_main                                      435     447     +12
send_ACK                                             229     232      +3
read_staticlease                                      90      93      +3
addStaticLease                                        60      61      +1
getIpByMac                                            46      43      -3
reservedIp                                            31      20     -11
keywords                                             304     288     -16
send_offer                                           428     403     -25
write_leases                                         225     193     -32
read_leases                                          184     143     -41
read_yn                                               64       -     -64
find_address                                         191       -    -191
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 5/6 up/down: 299/-383)          Total: -84 bytes

1 files changed, 16 insertions, 21 deletions

diff --git a/networking/udhcp/serverpacket.c b/networking/udhcp/serverpacket.c
index fca685d..afc0fb4 100644
--- a/networking/udhcp/serverpacket.c
+++ b/networking/udhcp/serverpacket.c
@@ -102,48 +102,44 @@ static void add_bootp_options(struct dhcpMessage *packet)
 int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
 {
 	struct dhcpMessage packet;
-	struct dhcpOfferedAddr *lease = NULL;
 	uint32_t req_align;
 	uint32_t lease_time_aligned = server_config.lease;
+	uint32_t static_lease_ip;
 	uint8_t *req, *lease_time;
 	struct option_set *curr;
 	struct in_addr addr;
 
-	uint32_t static_lease_ip;
-
 	init_packet(&packet, oldpacket, DHCPOFFER);
 
 	static_lease_ip = getIpByMac(server_config.static_leases, oldpacket->chaddr);
 
 	/* ADDME: if static, short circuit */
 	if (!static_lease_ip) {
-		/* the client is in our lease/offered table */
+		struct dhcpOfferedAddr *lease;
+
 		lease = find_lease_by_chaddr(oldpacket->chaddr);
+		/* the client is in our lease/offered table */
 		if (lease) {
-			if (!lease_expired(lease))
-				lease_time_aligned = lease->expires - time(0);
+			signed_leasetime_t tmp = lease->expires - time(NULL);
+			if (tmp >= 0)
+				lease_time_aligned = tmp;
 			packet.yiaddr = lease->yiaddr;
-		/* Or the client has a requested ip */
-		} else if ((req = get_option(oldpacket, DHCP_REQUESTED_IP))
+		/* Or the client has requested an ip */
+		} else if ((req = get_option(oldpacket, DHCP_REQUESTED_IP)) != NULL
 		 /* Don't look here (ugly hackish thing to do) */
-		 && memcpy(&req_align, req, 4)
+		 && (move_from_unaligned32(req_align, req), 1)
 		 /* and the ip is in the lease range */
 		 && ntohl(req_align) >= server_config.start_ip
 		 && ntohl(req_align) <= server_config.end_ip
-		 && !static_lease_ip /* Check that its not a static lease */
 		 /* and is not already taken/offered */
 		 && (!(lease = find_lease_by_yiaddr(req_align))
-			/* or its taken, but expired */ /* ADDME: or maybe in here */
+			/* or its taken, but expired */
 			|| lease_expired(lease))
 		) {
-			packet.yiaddr = req_align; /* FIXME: oh my, is there a host using this IP? */
-			/* otherwise, find a free IP */
+			packet.yiaddr = req_align;
+		/* otherwise, find a free IP */
 		} else {
-			/* Is it a static lease? (No, because find_address skips static lease) */
-			packet.yiaddr = find_address(0);
-			/* try for an expired lease */
-			if (!packet.yiaddr)
-				packet.yiaddr = find_address(1);
+			packet.yiaddr = find_free_or_expired_address();
 		}
 
 		if (!packet.yiaddr) {
@@ -164,8 +160,7 @@ int FAST_FUNC send_offer(struct dhcpMessage *oldpacket)
 
 		/* Make sure we aren't just using the lease time from the previous offer */
 		if (lease_time_aligned < server_config.min_lease)
-			lease_time_aligned = server_config.lease;
-		/* ADDME: end of short circuit */
+			lease_time_aligned = server_config.min_lease;
 	} else {
 		/* It is a static lease... use it */
 		packet.yiaddr = static_lease_ip;
@@ -217,7 +212,7 @@ int FAST_FUNC send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 		if (lease_time_aligned > server_config.lease)
 			lease_time_aligned = server_config.lease;
 		else if (lease_time_aligned < server_config.min_lease)
-			lease_time_aligned = server_config.lease;
+			lease_time_aligned = server_config.min_lease;
 	}
 
 	add_simple_option(packet.options, DHCP_LEASE_TIME, htonl(lease_time_aligned));