udhcp: code shrink; disable time and log server options

function                                             old     new   delta
add_server_options                                     -     100    +100
udhcp_add_simple_option                               92      90      -2
nobody_responds_to_arp                                88      85      -3
dhcp_options                                          66      62      -4
udhcp_add_option_string                              104      94     -10
udhcp_run_script                                     665     654     -11
dhcp_option_strings                                  203     188     -15
static.blank_chaddr                                   16       -     -16
send_ACK                                             211     180     -31
add_bootp_options                                     61       -     -61
udhcpd_main                                         1925    1846     -79
------------------------------------------------------------------------------
(add/remove: 1/2 grow/shrink: 0/8 up/down: 100/-232)         Total: -132 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 17 deletions

diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c
index 78b0d0a..efe67cf 100644
--- a/networking/udhcp/leases.c
+++ b/networking/udhcp/leases.c
@@ -29,16 +29,15 @@ static struct dyn_lease *oldest_expired_lease(void)
 }
 
 
-/* Clear every lease out that chaddr OR yiaddr matches and is nonzero */
-static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
+/* Clear out all leases with matching nonzero chaddr OR yiaddr.
+ * If chaddr == NULL, this is a conflict lease.
+ */
+static void clear_leases(const uint8_t *chaddr, uint32_t yiaddr)
 {
-	unsigned i, j;
-
-	for (j = 0; j < 16 && !chaddr[j]; j++)
-		continue;
+	unsigned i;
 
 	for (i = 0; i < server_config.max_leases; i++) {
-		if ((j != 16 && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
+		if ((chaddr && memcmp(g_leases[i].lease_mac, chaddr, 6) == 0)
 		 || (yiaddr && g_leases[i].lease_nip == yiaddr)
 		) {
 			memset(&g_leases[i], 0, sizeof(g_leases[i]));
@@ -47,7 +46,9 @@ static void clear_lease(const uint8_t *chaddr, uint32_t yiaddr)
 }
 
 
-/* Add a lease into the table, clearing out any old ones */
+/* Add a lease into the table, clearing out any old ones
+ * If chaddr == NULL, this is a conflict lease.
+ */
 struct dyn_lease* FAST_FUNC add_lease(
 		const uint8_t *chaddr, uint32_t yiaddr,
 		leasetime_t leasetime,
@@ -56,12 +57,12 @@ struct dyn_lease* FAST_FUNC add_lease(
 	struct dyn_lease *oldest;
 
 	/* clean out any old ones */
-	clear_lease(chaddr, yiaddr);
+	clear_leases(chaddr, yiaddr);
 
 	oldest = oldest_expired_lease();
 
 	if (oldest) {
-		oldest->hostname[0] = '\0';
+		memset(oldest, 0, sizeof(*oldest));
 		if (hostname) {
 			char *p;
 			if (hostname_len > sizeof(oldest->hostname))
@@ -74,7 +75,8 @@ struct dyn_lease* FAST_FUNC add_lease(
 				p++;
 			}
 		}
-		memcpy(oldest->lease_mac, chaddr, 6);
+		if (chaddr)
+			memcpy(oldest->lease_mac, chaddr, 6);
 		oldest->lease_nip = yiaddr;
 		oldest->expires = time(NULL) + leasetime;
 	}
@@ -119,10 +121,6 @@ struct dyn_lease* FAST_FUNC find_lease_by_nip(uint32_t nip)
 /* Check if the IP is taken; if it is, add it to the lease table */
 static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac)
 {
-	/* 16 zero bytes */
-	static const uint8_t blank_chaddr[16] = { 0 };
-	/* = { 0 } helps gcc to put it in rodata, not bss */
-
 	struct in_addr temp;
 	int r;
 
@@ -136,7 +134,7 @@ static int nobody_responds_to_arp(uint32_t nip, const uint8_t *safe_mac)
 	temp.s_addr = nip;
 	bb_info_msg("%s belongs to someone, reserving it for %u seconds",
 		inet_ntoa(temp), (unsigned)server_config.conflict_time);
-	add_lease(blank_chaddr, nip, server_config.conflict_time, NULL, 0);
+	add_lease(NULL, nip, server_config.conflict_time, NULL, 0);
 	return 0;
 }
 
@@ -173,7 +171,8 @@ uint32_t FAST_FUNC find_free_or_expired_nip(const uint8_t *safe_mac)
 		}
 	}
 
-	if (oldest_lease && is_expired_lease(oldest_lease)
+	if (oldest_lease
+	 && is_expired_lease(oldest_lease)
 	 && nobody_responds_to_arp(oldest_lease->lease_nip, safe_mac)
 	) {
 		return oldest_lease->lease_nip;