продолжаем вносить все
This commit is contained in:
193
lib/spider.js
Normal file
193
lib/spider.js
Normal file
@ -0,0 +1,193 @@
|
||||
'use strict'
|
||||
|
||||
const dgram = require('dgram')
|
||||
const Emiter = require('events')
|
||||
const bencode = require('bencode')
|
||||
const {Table, Node} = require('./table')
|
||||
const Token = require('./token')
|
||||
|
||||
const bootstraps = [{
|
||||
address: 'router.bittorrent.com',
|
||||
port: 6881
|
||||
}, {
|
||||
address: 'router.utorrent.com',
|
||||
port: 6881
|
||||
}, {
|
||||
address: 'dht.transmissionbt.com',
|
||||
port: 6881
|
||||
}, {
|
||||
address: 'dht.aelitis.com',
|
||||
port: 6881
|
||||
}]
|
||||
|
||||
function isValidPort(port) {
|
||||
return port > 0 && port < (1 << 16)
|
||||
}
|
||||
|
||||
function generateTid() {
|
||||
return parseInt(Math.random() * 99).toString()
|
||||
}
|
||||
|
||||
class Spider extends Emiter {
|
||||
constructor(client) {
|
||||
super()
|
||||
const options = arguments.length? arguments[0]: {}
|
||||
this.udp = dgram.createSocket('udp4')
|
||||
this.table = new Table(options.tableCaption || 1000)
|
||||
this.bootstraps = options.bootstraps || bootstraps
|
||||
this.token = new Token()
|
||||
this.client = client
|
||||
|
||||
this.walkInterval = 5;
|
||||
}
|
||||
|
||||
send(message, address) {
|
||||
const data = bencode.encode(message)
|
||||
this.udp.send(data, 0, data.length, address.port, address.address)
|
||||
}
|
||||
|
||||
findNode(id, address) {
|
||||
const message = {
|
||||
t: generateTid(),
|
||||
y: 'q',
|
||||
q: 'find_node',
|
||||
a: {
|
||||
id: id,
|
||||
target: Node.generateID()
|
||||
}
|
||||
}
|
||||
this.send(message, address)
|
||||
}
|
||||
|
||||
join() {
|
||||
this.bootstraps.forEach((bootstrap) => {
|
||||
this.findNode(this.table.id, bootstrap)
|
||||
})
|
||||
}
|
||||
|
||||
walk() {
|
||||
if(!this.client || this.client.isIdle()) {
|
||||
const node = this.table.shift()
|
||||
if (node) {
|
||||
this.findNode(Node.neighbor(node.id, this.table.id), {address: node.address, port: node.port})
|
||||
}
|
||||
}
|
||||
setTimeout(()=>this.walk(), this.walkInterval)
|
||||
}
|
||||
|
||||
onFoundNodes(data) {
|
||||
const nodes = Node.decodeNodes(data)
|
||||
nodes.forEach((node) => {
|
||||
if (node.id != this.table.id && isValidPort(node.port)) {
|
||||
this.table.add(node)
|
||||
}
|
||||
})
|
||||
this.emit('nodes', nodes)
|
||||
}
|
||||
|
||||
onFindNodeRequest(message, address) {
|
||||
const {t: tid, a: {id: nid, target: infohash}} = message
|
||||
|
||||
if (tid === undefined || target.length != 20 || nid.length != 20) {
|
||||
return
|
||||
}
|
||||
|
||||
this.send({
|
||||
t: tid,
|
||||
y: 'r',
|
||||
r: {
|
||||
id: Node.neighbor(nid, this.table.id),
|
||||
nodes: Node.encodeNodes(this.table.first())
|
||||
}
|
||||
}, address)
|
||||
}
|
||||
|
||||
onGetPeersRequest(message, address) {
|
||||
const {t: tid, a: {id: nid, info_hash: infohash}} = message
|
||||
|
||||
if (tid === undefined || infohash.length != 20 || nid.length != 20) {
|
||||
return
|
||||
}
|
||||
|
||||
this.send({
|
||||
t: tid,
|
||||
y: 'r',
|
||||
r: {
|
||||
id: Node.neighbor(nid, this.table.id),
|
||||
nodes: Node.encodeNodes(this.table.first()),
|
||||
token: this.token.token
|
||||
}
|
||||
}, address)
|
||||
|
||||
this.emit('unensureHash', infohash.toString('hex').toUpperCase())
|
||||
}
|
||||
|
||||
onAnnouncePeerRequest(message, address) {
|
||||
let {t: tid, a: {info_hash: infohash, token: token, id: id, implied_port: implied, port: port}} = message
|
||||
if (!tid) return
|
||||
|
||||
if (!this.token.isValid(token)) return
|
||||
|
||||
port = (implied != undefined && implied != 0) ? address.port : (port || 0)
|
||||
if (!isValidPort(port)) return
|
||||
|
||||
this.send({ t: tid, y: 'r', r: { id: Node.neighbor(id, this.table.id) } }, address)
|
||||
|
||||
let addressPair = {
|
||||
address: address.address,
|
||||
port: port
|
||||
};
|
||||
this.emit('ensureHash', infohash.toString('hex').toUpperCase(), addressPair)
|
||||
if(this.client) {
|
||||
this.client.add(addressPair, infohash);
|
||||
}
|
||||
}
|
||||
|
||||
onPingRequest(message, address) {
|
||||
this.send({ t: message.t, y: 'r', r: { id: Node.neighbor(message.a.id, this.table.id) } }, address)
|
||||
}
|
||||
|
||||
parse(data, address) {
|
||||
try {
|
||||
const message = bencode.decode(data)
|
||||
if (message.y.toString() == 'r' && message.r.nodes) {
|
||||
this.onFoundNodes(message.r.nodes)
|
||||
} else if (message.y.toString() == 'q') {
|
||||
switch(message.q.toString()) {
|
||||
case 'get_peers':
|
||||
this.onGetPeersRequest(message, address)
|
||||
break
|
||||
case 'announce_peer':
|
||||
this.onAnnouncePeerRequest(message, address)
|
||||
break
|
||||
case 'find_node':
|
||||
this.onFindNodeRequest(message, address)
|
||||
break
|
||||
case 'ping':
|
||||
this.onPingRequest(message, address)
|
||||
break
|
||||
}
|
||||
}
|
||||
} catch (err) {}
|
||||
}
|
||||
|
||||
listen(port) {
|
||||
this.udp.bind(port)
|
||||
this.udp.on('listening', () => {
|
||||
console.log(`Listen on ${this.udp.address().address}:${this.udp.address().port}`)
|
||||
})
|
||||
this.udp.on('message', (data, addr) => {
|
||||
this.parse(data, addr)
|
||||
})
|
||||
this.udp.on('error', (err) => {})
|
||||
setInterval(() => {
|
||||
if(!this.client || this.client.isIdle()) {
|
||||
this.join()
|
||||
}
|
||||
}, 3000)
|
||||
this.join()
|
||||
this.walk()
|
||||
}
|
||||
}
|
||||
|
||||
module.exports = Spider
|
Reference in New Issue
Block a user