Revert "(legacy) remove cache stuff from find_interface_ipv6"

This reverts commit 47aaef9.

src/etc/inc/gwlb.inc

@@ -190,22 +190,22 @@ EOD;
 				if (is_linklocal($gateway['gateway'])) {
 					$gwifip = find_interface_ipv6_ll($gateway['interface'], true);
 				} else {
-					$gwifip = find_interface_ipv6($gateway['interface']);
+					$gwifip = find_interface_ipv6($gateway['interface'], true);
 				}
 			} else {
 				/* 'monitor' has been set, so makes sure it has precedence over
 				 * 'gateway' in defining the source IP. Otherwise if 'gateway'
 				 * is a local link and 'monitor' is global routable then the
 				 * ICMP6 response would not find its way back home...
 				 */
-				$gwifip = find_interface_ipv6($gateway['interface']);
+				$gwifip = find_interface_ipv6($gateway['interface'], true);
 				if (is_linklocal($gateway['monitor'])) {
 					if (!strstr($gateway['monitor'], '%')) {
 						$gateway['monitor'] .= "%{$gateway['interface']}";
 					}
 				} else {
 					// Monitor is a routable address, so use a routable address for the "src" part
-					$gwifip = find_interface_ipv6($gateway['interface']);
+					$gwifip = find_interface_ipv6($gateway['interface'], true);
 				}
 			}
 

src/etc/inc/interfaces.inc

@@ -2840,7 +2840,7 @@ function interface_configure($interface = 'wan', $reloadall = false, $linkupeven
 {
 	global $config;
 	global $interface_sn_arr_cache;
-	global $interface_snv6_arr_cache;
+	global $interface_snv6_arr_cache, $interface_ipv6_arr_cache;
 
 	$wancfg = $config['interfaces'][$interface];
 
@@ -2957,6 +2957,7 @@ function interface_configure($interface = 'wan', $reloadall = false, $linkupeven
 
 	/* invalidate interface/ip/sn cache */
 	unset($interface_sn_arr_cache[$realif]);
+	unset($interface_ipv6_arr_cache[$realif]);
 	unset($interface_snv6_arr_cache[$realif]);
 
 	$tunnelif = substr($realif, 0, 3);
@@ -3157,6 +3158,7 @@ function interface_track6_configure($interface = 'lan', $wancfg, $linkupevent =
 function interface_track6_6rd_configure($interface = 'lan', $lancfg)
 {
 	global $config;
+	global $interface_ipv6_arr_cache;
 	global $interface_snv6_arr_cache;
 
 	if (!is_array($lancfg))
@@ -3207,6 +3209,7 @@ function interface_track6_6rd_configure($interface = 'lan', $lancfg)
 	$oip = find_interface_ipv6($lanif);
 	if (is_ipaddrv6($oip))
 		mwexec("/sbin/ifconfig {$lanif} inet6 {$oip} delete");
+	unset($interface_ipv6_arr_cache[$lanif]);
 	unset($interface_snv6_arr_cache[$lanif]);
 	log_error("rd6 {$interface} with ipv6 address {$rd6lan} based on {$lancfg['track6-interface']} ipv4 {$ip4address}");
 	mwexec("/sbin/ifconfig {$lanif} inet6 {$rd6lan} prefixlen 64");
@@ -3217,6 +3220,7 @@ function interface_track6_6rd_configure($interface = 'lan', $lancfg)
 function interface_track6_6to4_configure($interface = 'lan', $lancfg)
 {
 	global $config;
+	global $interface_ipv6_arr_cache;
 	global $interface_snv6_arr_cache;
 
 	if (!is_array($lancfg))
@@ -3263,6 +3267,7 @@ function interface_track6_6to4_configure($interface = 'lan', $lancfg)
 	$oip = find_interface_ipv6($lanif);
 	if (is_ipaddrv6($oip))
 		mwexec("/sbin/ifconfig {$lanif} inet6 {$oip} delete");
+	unset($interface_ipv6_arr_cache[$lanif]);
 	unset($interface_snv6_arr_cache[$lanif]);
 	log_error("sixto4 {$interface} with ipv6 address {$sixto4lan} based on {$lancfg['track6-interface']} ipv4 {$ip4address}");
 	mwexec("/sbin/ifconfig {$lanif} inet6 {$sixto4lan} prefixlen 64");
@@ -4506,23 +4511,39 @@ function find_interface_ip($interface) {
 				if (isset($ifinfo['ipaddr'])) {
 						return $ifinfo['ipaddr'];
 				}
+		} else {
+				return null;
 		}
-		return null;
 }
 
 /*
  * find_interface_ipv6($interface): return the interface ip (first found)
  */
-function find_interface_ipv6($interface) {
-		// a bit obscure, why should this be different then find_interface_ip?
-		$interface = get_real_interface(trim($interface));
-		if (does_interface_exist($interface)) {
-				$ifinfo = pfSense_get_interface_addresses($interface);
-				if (isset($ifinfo['ipaddr6'])) {
-						return $ifinfo['ipaddr6'];
-				}
+function find_interface_ipv6($interface, $flush = false) {
+	global $interface_ipv6_arr_cache;
+	global $config;
+
+	if (!isset($interface_ipv6_arr_cache) || !is_array($interface_ipv6_arr_cache)) {
+		$interface_ipv6_arr_cache = array();
+	}
+
+	$interface = trim($interface);
+	$interface = get_real_interface($interface);
+
+	if (!does_interface_exist($interface))
+		return;
+
+	/* Setup IP cache */
+	if (!isset($interface_ipv6_arr_cache[$interface]) or $flush) {
+		$ifinfo = pfSense_get_interface_addresses($interface);
+		if (isset($ifinfo['ipaddr6'])) {
+			$interface_ipv6_arr_cache[$interface] = $ifinfo['ipaddr6'];
+		} else {
+			return null;
 		}
-		return null;
+	}
+
+	return $interface_ipv6_arr_cache[$interface];
 }
 
 /*