Add interface_mtu_wanted_for_pppoe()

Returns the MTU wanted if an interface or vlan is used as a PPPoE port.

1 files changed, 38 insertions, 0 deletions

diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index 180ce6e..3e9fd21 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -3077,6 +3077,44 @@ function interface_vlan_adapt_mtu($vlanifs, $mtu) {
 	}
 }
 
+function interface_mtu_wanted_for_pppoe($realif) {
+	global $config;
+
+	$mtu = 0;
+
+	if (is_array($config['ppps']) && is_array($config['ppps']['ppp'])) {
+		foreach ($config['ppps']['ppp'] as $ppp) {
+			if ($ppp['type'] == "pppoe") {
+				$ports = explode(',',$ppp['ports']);
+				$mtu_wanted = 1500;
+				foreach ($ports as $pid => $port) {
+					if (get_real_interface($port) == $realif) {
+						// use the MTU configured on the interface ...
+						if (is_array($config['interfaces'])) {
+							foreach ($config['interfaces'] as $interface) {
+								if ($interface['if'] != $ppp['if'])
+									continue;
+								if (!empty($interface['mtu']))
+									$mtu_wanted = intval($interface['mtu']) + 8;
+							}
+						}
+						// ... unless there is an MTU configured on the port in question
+						if (!empty($ppp['mtu'])) {
+							$mtus = explode(',',$ppp['mtu']);
+							if (!empty($mtus[$pid]))
+								$mtu_wanted = intval($mtus[$pid]) + 8;
+						}
+						if ($mtu_wanted > $mtu)
+							$mtu = $mtu_wanted;
+					}
+				}
+			}
+		}
+	}
+
+	return $mtu;
+}
+
 function interface_configure($interface = "wan", $reloadall = false, $linkupevent = false) {
 	global $config, $g;
 	global $interface_sn_arr_cache, $interface_ip_arr_cache;