| "use strict"; |
| |
| const {isIP} = require("net"); |
| const execa = require("execa"); |
| const dests = new Set(["default", "0.0.0.0", "0.0.0.0/0", "::", "::/0"]); |
| |
| const args = { |
| v4: ["-rn", "-f", "inet"], |
| v6: ["-rn", "-f", "inet6"], |
| }; |
| |
| const parse = stdout => { |
| let result; |
| |
| (stdout || "").trim().split("\n").some(line => { |
| const results = line.split(/ +/) || []; |
| const target = results[0]; |
| const gateway = results[1]; |
| const iface = results[7]; |
| if (dests.has(target) && gateway && isIP(gateway)) { |
| result = {gateway, interface: (iface ? iface : null)}; |
| return true; |
| } |
| }); |
| |
| if (!result) { |
| throw new Error("Unable to determine default gateway"); |
| } |
| |
| return result; |
| }; |
| |
| const promise = async family => { |
| const {stdout} = await execa("netstat", args[family]); |
| return parse(stdout); |
| }; |
| |
| const sync = family => { |
| const {stdout} = execa.sync("netstat", args[family]); |
| return parse(stdout); |
| }; |
| |
| module.exports.v4 = () => promise("v4"); |
| module.exports.v6 = () => promise("v6"); |
| |
| module.exports.v4.sync = () => sync("v4"); |
| module.exports.v6.sync = () => sync("v6"); |