Merge pull request #2 from joelheaps/ipv6-bugfixes

Change compose version and add kernel module check before loading IPv6 NAT rules

docker-compose.yml

@@ -1,4 +1,4 @@
-version: "3.8"
+version: "2.4"
 
 services:
   wg-easy:

src/config.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const { release } = require('./package.json');
+const childProcess = require('child_process');
 
 module.exports.RELEASE = release;
 module.exports.PORT = process.env.PORT || 51821;
@@ -20,15 +21,28 @@ module.exports.WG_DEFAULT_DNS6 = typeof process.env.WG_DEFAULT_DNS6 === 'string'
   : '2606:4700:4700::1111';
 module.exports.WG_ALLOWED_IPS = process.env.WG_ALLOWED_IPS || '0.0.0.0/0, ::/0';
 
-module.exports.WG_POST_UP = process.env.WG_POST_UP || `
-iptables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o eth0 -j MASQUERADE;
-iptables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
-iptables -A FORWARD -i wg0 -j ACCEPT;
-iptables -A FORWARD -o wg0 -j ACCEPT;
-ip6tables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS6.replace('x', '0')}/64 -o eth0 -j MASQUERADE;
-ip6tables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
-ip6tables -A FORWARD -i wg0 -j ACCEPT;
-ip6tables -A FORWARD -o wg0 -j ACCEPT;
-`.split('\n').join(' ');
+// Set WG_POST_UP to allow IPv6 NAT and forwarding only if the required kernel module is available
+const modules = childProcess.execSync('lsmod', {
+  shell: 'bash',
+})
+
+module.exports.WG_POST_UP = process.env.WG_POST_UP
+if (!process.env.WG_POST_UP) {
+  module.exports.WG_POST_UP = `
+  iptables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS.replace('x', '0')}/24 -o eth0 -j MASQUERADE;
+  iptables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
+  iptables -A FORWARD -i wg0 -j ACCEPT;
+  iptables -A FORWARD -o wg0 -j ACCEPT;`
+  
+  if (modules.includes("ip6table_nat")) {
+    module.exports.WG_POST_UP += `ip6tables -t nat -A POSTROUTING -s ${module.exports.WG_DEFAULT_ADDRESS6.replace('x', '0')}/64 -o eth0 -j MASQUERADE;
+  ip6tables -A INPUT -p udp -m udp --dport 51820 -j ACCEPT;
+  ip6tables -A FORWARD -i wg0 -j ACCEPT;
+  ip6tables -A FORWARD -o wg0 -j ACCEPT;`
+  }
+  
+  module.exports.WG_POST_UP = module.exports.WG_POST_UP.split('\n').join(' ');
+}
+
 
 module.exports.WG_POST_DOWN = process.env.WG_POST_DOWN || '';