respondd

#!/usr/bin/env node

const dgram = require('dgram')
const socket = dgram.createSocket('udp6')
const fs = require('fs')
const zlib = require('zlib')
const os = require('os')
const process = require('child_process')
const myproc = require('process')

const defConfig = {
  "bat_iface": "bat0",
  "mcast_group": "ff02::2:1001",
  "mcast_iface": "bat0",
  "port": "1001",
  "site_code": undefined
}

function getNodeinfo() {
  return {
    "software": {
      "autoupdater": {
        "enabled": false
      },
      "batman-adv": {
        "version": getFileContents("/sys/module/batman_adv/version")
      },
      "fastd": {
        "enabled": isProcessRunning("fastd")
      },
      "tunneldigger": {
        "enabled": isProcessRunning("l2tp_broker")
      }
    },
    "network": {
      "addresses": getV6AddrForInterface(getConfig("mcast_iface")),
      "mesh": getMeshAddresses(),
      "mac": getPrimaryMac()
    },
    "system": {
      "site_code": getConfig("site_code")
    },
    "hostname": getConfig("hostname"),
    "hardware": {
      "model": os.cpus()[0].model,
      "nproc": os.cpus().length
    }
  }
}

function getStatistics() {
  return {
    "traffic": getTrafficStats(),
    "memory": {
      "total": os.totalmem(),
      "free": os.freemem()
    },
    "uptime": os.uptime(),
    "loadavg": os.loadavg()[0],
    "processes": {
      "running": parseInt(evalExec("ps ax | awk '{print $3}' | grep R | wc -l")),
      "total": parseInt(evalExec("ps ax | wc -l")) - 1,
    }
  }
}

function getNeighbours() {
  return {
    "batadv": JSON.parse(evalExec("sudo ./bat-list-neighbours"))
  }
}

function getV6AddrForInterface(iface) {
  try {
    return os.networkInterfaces()[iface].filter((a) => a.family == "IPv6").map((a) => a.address)
  } catch (e) {
    return undefined
  }
}

function isProcessRunning(name) {
  try {
    return evalExec("ps ax | grep "+name+" | grep -v grep").length > 0
  } catch (e) {
    return false
  }
}

function evalExec(line) {
  try {
    return process.execSync(line).toString().trim()
  } catch (e) {
    return undefined
  }
}

function getFileContents(name) {
  try {
    return fs.readFileSync(name).toString().trim()
  } catch (e) {
    return undefined
  }
}

function getTrafficStats() {
  try {
    var res = {}
    var vs = evalExec("/sbin/ethtool -S " + getConfig("bat_iface") + " | head -n 12 | tail -n 11").split("\n")
    vs.forEach((v) => {
      var x = v.split(": ")
      var group = x[0].trim()
      var type = "packets"
      var val = parseInt(x[1].trim())
      if (group.indexOf("_bytes") > -1) {
        group = group.substring(0,group.length-6)
        type = "bytes"
      }
      if (group.indexOf("_dropped") > -1) {
        group = group.substring(0,group.length-8)
        type = "dropped"
      }
      if (!(group in res)) res[group] = {}
      res[group][type] = val
    })
    return res
  } catch (e) {
    return undefined
  }
}

function getMeshAddresses() {
  var bat = getConfig("bat_iface")
  var data = {
    "interfaces": {
      "tunnel": evalExec("cat /sys/class/net/"+bat+"/lower_*/address").split("\n"),
      "other": [getPrimaryMac()]
    }
  }
  var res = {}
  res[bat] = data
  return res
}

function getNodeId() {
  return getPrimaryMac().replace(/:/g,"")
}

function getPrimaryMac() {
  return getMac(getConfig("mcast_iface"));
}

function getMac(iface) {
  try {
    return os.networkInterfaces()[iface][0].mac
  } catch (e) {
    return "00:00:00:00:00:00"
  }
}

function getData(what) {
  var data = {}
  switch(what) {
    case "nodeinfo": data = getNodeinfo(); break
    case "statistics": data = getStatistics(); break
    case "neighbours": data = getNeighbours(); break
    default: console.log("Unknown data type: " + what)
  }
  data.node_id = getNodeId()
  var res = {}
  res[what] = data
  return res
}

var config = {}

try {
  config = JSON.parse(fs.readFileSync("./config.json"))
} catch (err) {
  console.log("no config file found")
}

function getConfig(opt) {
  if (opt == "listen")
    return getV6AddrForInterface(getConfig("mcast_iface")).filter((a) => a.startsWith("fe80:"))[0] + "%" + getConfig("mcast_iface")
  if (opt in config) return config[opt]
  if (opt == "hostname") return os.hostname()
  else return defConfig[opt]
}

socket.on('error', (err) => {
  console.log("socket error: " + err)
  socket.close()
})

socket.on('message', (msg, rinfo) => {
  if (!rinfo.address.startsWith("f")) return
  msg = msg.toString()
  console.log("message from: "+rinfo.address+": "+msg)
  if (msg.startsWith("GET ")) {
    // Multi case
    var whats = msg.substring(4).split(" ")
    whats.forEach((what) => {
      zlib.deflateRaw(new Buffer(JSON.stringify(getData(what.trim()))), (_, data) => {
        socket.send(data, 0, data.length, rinfo.port, rinfo.address + "%" + getConfig("mcast_iface"), (err) => { if (err) console.log(err) })
      })
    })
  } else {
    // Single case
    var res = new Buffer(JSON.stringify(getData(msg.trim())))
    socket.send(res, 0, res.length, rinfo.port, rinfo.address + "%" + getConfig("mcast_iface"), (err) => { if (err) console.log(err) })
  }
})

socket.on('listening', () => {
  var addr = socket.address()
  console.log("socket listening on " + addr.address + ":" + addr.port)
})

socket.bind(getConfig("port"), () => {
  socket.addMembership(getConfig("mcast_group"), getConfig("listen"))
  myproc.setgid('nogroup')
  myproc.setuid('nobody')
})