100 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| "use strict";
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| 
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| const {isIP} = require("net");
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| const {networkInterfaces} = require("os");
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| const execa = require("execa");
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| 
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| const gwArgs = "path Win32_NetworkAdapterConfiguration where IPEnabled=true get DefaultIPGateway,GatewayCostMetric,IPConnectionMetric,Index /format:table".split(" ");
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| const ifArgs = index => `path Win32_NetworkAdapter where Index=${index} get NetConnectionID,MACAddress /format:table`.split(" ");
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| 
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| const spawnOpts = {
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|   windowsHide: true,
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| };
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| 
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| // Parsing tables like this. The final metric is GatewayCostMetric + IPConnectionMetric
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| //
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| // DefaultIPGateway             GatewayCostMetric  Index  IPConnectionMetric
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| // {"1.2.3.4", "2001:db8::1"}   {0, 256}           12     25
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| // {"2.3.4.5"}                  {25}               12     55
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| function parseGwTable(gwTable, family) {
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|   let [bestGw, bestMetric, bestId] = [null, null, null];
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| 
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|   for (let line of (gwTable || "").trim().split(/\r?\n/).splice(1)) {
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|     line = line.trim();
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|     const [_, gwArr, gwCostsArr, id, ipMetric] = /({.+?}) +?({.+?}) +?([0-9]+) +?([0-9]+)/g.exec(line) || [];
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|     if (!gwArr) continue;
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| 
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|     const gateways = (gwArr.match(/"(.+?)"/g) || []).map(match => match.substring(1, match.length - 1));
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|     const gatewayCosts = (gwCostsArr.match(/[0-9]+/g) || []);
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| 
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|     for (const [index, gateway] of Object.entries(gateways)) {
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|       if (!gateway || `v${isIP(gateway)}` !== family) continue;
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| 
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|       const metric = parseInt(gatewayCosts[index]) + parseInt(ipMetric);
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|       if (!bestGw || metric < bestMetric) {
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|         [bestGw, bestMetric, bestId] = [gateway, metric, id];
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|       }
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|     }
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|   }
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| 
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|   if (bestGw) return [bestGw, bestId];
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| }
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| 
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| function parseIfTable(ifTable) {
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|   const line = (ifTable || "").trim().split("\n")[1];
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| 
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|   let [mac, name] = line.trim().split(/\s+/);
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|   mac = mac.toLowerCase();
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| 
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|   // try to get the interface name by matching the mac to os.networkInterfaces to avoid wmic's encoding issues
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|   // https://github.com/silverwind/default-gateway/issues/14
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|   for (const [osname, addrs] of Object.entries(networkInterfaces())) {
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|     for (const addr of addrs) {
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|       if (addr && addr.mac && addr.mac.toLowerCase() === mac) {
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|         return osname;
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|       }
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|     }
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|   }
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|   return name;
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| }
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| 
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| const promise = async family => {
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|   const {stdout} = await execa("wmic", gwArgs, spawnOpts);
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|   const [gateway, id] = parseGwTable(stdout, family) || [];
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| 
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|   if (!gateway) {
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|     throw new Error("Unable to determine default gateway");
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|   }
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| 
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|   let name;
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|   if (id) {
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|     const {stdout} = await execa("wmic", ifArgs(id), spawnOpts);
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|     name = parseIfTable(stdout);
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|   }
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| 
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|   return {gateway, interface: name ? name : null};
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| };
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| 
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| const sync = family => {
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|   const {stdout} = execa.sync("wmic", gwArgs, spawnOpts);
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|   const [gateway, id] = parseGwTable(stdout, family) || [];
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| 
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|   if (!gateway) {
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|     throw new Error("Unable to determine default gateway");
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|   }
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| 
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|   let name;
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|   if (id) {
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|     const {stdout} = execa.sync("wmic", ifArgs(id), spawnOpts);
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|     name = parseIfTable(stdout);
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|   }
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| 
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|   return {gateway, interface: name ? name : null};
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| };
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| 
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| module.exports.v4 = () => promise("v4");
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| module.exports.v6 = () => promise("v6");
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| 
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| module.exports.v4.sync = () => sync("v4");
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| module.exports.v6.sync = () => sync("v6");
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