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Return connection immediately, add connect event.
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Resolving the connection ASAP allows the client to close it during a
connection attempt. Instead, a connect event is used to signal success.
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@retrixe
retrixe committed Sep 17, 2022
1 parent 1942c40 commit 6e9c45a
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Showing 5 changed files with 178 additions and 158 deletions.
71 changes: 47 additions & 24 deletions android/app/src/main/java/com/enderchat/modules/connection/ConnectionModule.kt
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Original file line number Diff line number Diff line change
Expand Up @@ -125,18 +125,35 @@ class ConnectionModule(reactContext: ReactApplicationContext)
// Start thread which handles creating the connection and then reads packets from it.
// This avoids blocking the main thread on writeLock and keeps the UI thread responsive.
scope.launch(Dispatchers.IO) {
lock.writeLock().lock()
val socket: Socket
val connectionId = UUID.randomUUID()
try {
// Only one connection at a time.
lock.write {
// Only one connection at a time.
directlyCloseConnection()

// Create socket and connection ID.
socket = Socket()
socket.soTimeout = 20 * 1000
this@ConnectionModule.socket = socket
this@ConnectionModule.connectionId = connectionId
promise.resolve(connectionId.toString())
}
} catch (e: Exception) {
directlyCloseConnection()
promise.reject(e)
return@launch
}

// Create socket and connection ID.
socket = Socket()
try {
// Connect to the server.
socket.connect(InetSocketAddress(host, port), 30 * 1000)
socket.soTimeout = 20 * 1000
this@ConnectionModule.connectionId = connectionId

// Send connect event.
val params = Arguments.createMap().apply {
putString("connectionId", connectionId.toString())
}
sendEvent(reactContext = reactApplicationContext, "ecm:connect", params)

// Create data to send in Handshake.
val portBuf = ByteBuffer.allocate(2)
Expand All @@ -154,15 +171,13 @@ class ConnectionModule(reactContext: ReactApplicationContext)
// Send Login Start packet.
val loginPacketData = Base64.decode(loginPacket, Base64.DEFAULT)
socket.getOutputStream().write(Packet(0x00, loginPacketData).writePacket())

// Update the current socket and resolve/reject.
this@ConnectionModule.socket = socket
lock.writeLock().unlock()
promise.resolve(connectionId.toString())
} catch (e: Exception) {
directlyCloseConnection()
lock.writeLock().unlock()
promise.reject(e)
lock.write {
if (this@ConnectionModule.socket == socket) {
directlyCloseConnection()
sendErrorEvent(connectionId, e)
} else sendCloseEvent(connectionId)
}
return@launch
}

Expand Down Expand Up @@ -252,24 +267,32 @@ class ConnectionModule(reactContext: ReactApplicationContext)
} catch (e: Exception) {
if (lockAcquired) lock.readLock().unlock()
lock.write { if (this@ConnectionModule.socket == socket) directlyCloseConnection() }
val params = Arguments.createMap().apply {
putString("connectionId", connectionId.toString())
putString("stackTrace", e.stackTraceToString())
putString("message", e.message)
}
sendEvent(reactContext = reactApplicationContext, "ecm:error", params)
sendErrorEvent(connectionId, e)
break
}
}

// Dispatch close event to JS.
// The only way this.socket != socket is if directlyCloseConnection was called.
// If isInputStream returns -1, for now we assume the socket was closed too.
val params = Arguments.createMap().apply {
putString("connectionId", connectionId.toString())
}
sendEvent(reactContext = reactApplicationContext, "ecm:close", params)
sendCloseEvent(connectionId)
}
}

private fun sendErrorEvent(connectionId: UUID, e: Exception) {
val params = Arguments.createMap().apply {
putString("connectionId", connectionId.toString())
putString("stackTrace", e.stackTraceToString())
putString("message", e.message)
}
sendEvent(reactContext = reactApplicationContext, "ecm:error", params)
}

private fun sendCloseEvent(connectionId: UUID) {
val params = Arguments.createMap().apply {
putString("connectionId", connectionId.toString())
}
sendEvent(reactContext = reactApplicationContext, "ecm:close", params)
}

private fun sendEvent(reactContext: ReactContext, eventName: String, params: WritableMap?) {
Expand Down
3 changes: 2 additions & 1 deletion src/minecraft/connection/index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,8 @@ export interface ServerConnection extends events.EventEmitter {

close: () => void

on: ((event: 'packet', listener: (packet: Packet) => void) => this) &
on: ((event: 'connect', listener: () => void) => this) &
((event: 'packet', listener: (packet: Packet) => void) => this) &
((event: 'error', listener: (error: Error) => void) => this) &
((event: 'close', listener: () => void) => this) &
((event: string, listener: Function) => this)
Expand Down
253 changes: 122 additions & 131 deletions src/minecraft/connection/javascript.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -83,140 +83,131 @@ export class JavaScriptServerConnection

const initiateJavaScriptConnection = async (opts: ConnectionOptions) => {
const [host, port] = await resolveHostname(opts.host, opts.port)
return await new Promise<ServerConnection>((resolve, reject) => {
const socket = net.createConnection({ host, port })
const conn = new JavaScriptServerConnection(socket, opts)
let resolved = false
const { accessToken, selectedProfile } = opts
socket.on('connect', () => {
// Create data to send in Handshake.
const portBuf = Buffer.alloc(2)
portBuf.writeUInt16BE(port)
const handshakeData = [
writeVarInt(opts.protocolVersion),
host,
portBuf,
writeVarInt(2)
]
// Initialise Handshake with server.
socket.write(makeBasePacket(0x00, concatPacketData(handshakeData)), () =>
// Send Login Start packet.
socket.write(makeBasePacket(0x00, getLoginPacket(opts)), () => {
resolved = true
resolve(conn)
})
)
})
socket.on('close', () => {
conn.closed = true
conn.emit('close')
})
socket.on('error', err => {
if (!resolved) reject(err)
else {
conn.disconnectReason = err.message
conn.emit('error', err)
}
})
const lock = new Semaphore(1)
socket.on('data', newData => {
// Handle timeout after 20 seconds of no data.
if (conn.disconnectTimer) clearTimeout(conn.disconnectTimer)
conn.disconnectTimer = setTimeout(() => conn.close(), 20000)
// Run after interactions to improve user experience.
InteractionManager.runAfterInteractions(async () => {
await lock.acquire()
try {
// Note: the entire packet is encrypted, including the length fields and the packet's data.
// https://github.com/PrismarineJS/node-minecraft-protocol/blob/master/src/transforms/encryption.js
let finalData = newData
if (conn.aesDecipher) finalData = conn.aesDecipher.update(newData)
// Buffer data for read.
conn.bufferedData = Buffer.concat([conn.bufferedData, finalData])
while (true) {
const packet = conn.compressionEnabled
? await parseCompressedPacket(conn.bufferedData)
: parsePacket(conn.bufferedData)
if (packet) {
// Remove packet from buffered data.
conn.bufferedData =
conn.bufferedData.length <= packet.packetLength
? Buffer.alloc(0) // Avoid errors shortening.
: conn.bufferedData.slice(packet.packetLength)
// Internally handle login packets.
const is1164 =
conn.options.protocolVersion >= protocolMap['1.16.4']
const is117 = conn.options.protocolVersion >= protocolMap[1.17]
const is119 = conn.options.protocolVersion >= protocolMap[1.19]
const is1191 =
conn.options.protocolVersion >= protocolMap['1.19.1']
if (packet.id === 0x03 && !conn.loggedIn /* Set Compression */) {
const [threshold] = readVarInt(packet.data)
conn.compressionThreshold = threshold
conn.compressionEnabled = threshold >= 0
} else if (packet.id === 0x02 && !conn.loggedIn) {
conn.loggedIn = true // Login Success
} else if (
// Keep Alive (clientbound)
(packet.id === 0x1f && is1164 && !is117) ||
(packet.id === 0x21 && is117 && !is119) ||
(packet.id === 0x1e && is119 && !is1191) ||
(packet.id === 0x20 && is1191)
) {
const id = is1191 ? 0x12 : is119 ? 0x11 : is117 ? 0x0f : 0x10
conn
.writePacket(id, packet.data)
.catch(err => conn.emit('error', err))
} else if (
// Disconnect (login) or Disconnect (play)
(packet.id === 0x00 && !conn.loggedIn) ||
(packet.id === 0x19 && conn.loggedIn && is1164 && !is117) ||
(packet.id === 0x1a && conn.loggedIn && is117 && !is119) ||
(packet.id === 0x17 && conn.loggedIn && is119 && !is1191) ||
(packet.id === 0x19 && conn.loggedIn && is1191)
) {
const [chatLength, chatVarIntLength] = readVarInt(packet.data)
conn.disconnectReason = packet.data
.slice(chatVarIntLength, chatVarIntLength + chatLength)
.toString('utf8')
} else if (packet.id === 0x04 && !conn.loggedIn) {
/* Login Plugin Request */
const [msgId] = readVarInt(packet.data)
const rs = concatPacketData([writeVarInt(msgId), false])
conn.writePacket(0x02, rs).catch(err => conn.emit('error', err))
} else if (packet.id === 0x01 && !conn.loggedIn) {
/* Encryption Request */
if (!accessToken || !selectedProfile) {
conn.disconnectReason =
'{"text":"This server requires a premium account to be logged in!"}'
conn.close()
continue
}
handleEncryptionRequest(
packet,
accessToken,
selectedProfile,
conn,
is119,
async (secret: Buffer, response: Buffer) => {
const AES_ALG = 'aes-128-cfb8'
conn.aesDecipher = createDecipheriv(AES_ALG, secret, secret)
await conn.writePacket(0x01, response)
conn.aesCipher = createCipheriv(AES_ALG, secret, secret)
}
)
const socket = net.createConnection({ host, port })
const conn = new JavaScriptServerConnection(socket, opts)
const { accessToken, selectedProfile } = opts
socket.on('connect', () => {
conn.emit('connect')
// Create data to send in Handshake.
const portBuf = Buffer.alloc(2)
portBuf.writeUInt16BE(port)
const handshakeData = [
writeVarInt(opts.protocolVersion),
host,
portBuf,
writeVarInt(2)
]
// Initialise Handshake with server.
socket.write(makeBasePacket(0x00, concatPacketData(handshakeData)), () =>
// Send Login Start packet.
socket.write(makeBasePacket(0x00, getLoginPacket(opts)))
)
})
socket.on('close', () => {
conn.closed = true
conn.emit('close')
})
socket.on('error', err => {
conn.disconnectReason = err.message
conn.emit('error', err)
})
const lock = new Semaphore(1)
socket.on('data', newData => {
// Handle timeout after 20 seconds of no data.
if (conn.disconnectTimer) clearTimeout(conn.disconnectTimer)
conn.disconnectTimer = setTimeout(() => conn.close(), 20000)
// Run after interactions to improve user experience.
InteractionManager.runAfterInteractions(async () => {
await lock.acquire()
try {
// Note: the entire packet is encrypted, including the length fields and the packet's data.
// https://github.com/PrismarineJS/node-minecraft-protocol/blob/master/src/transforms/encryption.js
let finalData = newData
if (conn.aesDecipher) finalData = conn.aesDecipher.update(newData)
// Buffer data for read.
conn.bufferedData = Buffer.concat([conn.bufferedData, finalData])
while (true) {
const packet = conn.compressionEnabled
? await parseCompressedPacket(conn.bufferedData)
: parsePacket(conn.bufferedData)
if (packet) {
// Remove packet from buffered data.
conn.bufferedData =
conn.bufferedData.length <= packet.packetLength
? Buffer.alloc(0) // Avoid errors shortening.
: conn.bufferedData.slice(packet.packetLength)
// Internally handle login packets.
const is1164 = conn.options.protocolVersion >= protocolMap['1.16.4']
const is117 = conn.options.protocolVersion >= protocolMap[1.17]
const is119 = conn.options.protocolVersion >= protocolMap[1.19]
const is1191 = conn.options.protocolVersion >= protocolMap['1.19.1']
if (packet.id === 0x03 && !conn.loggedIn /* Set Compression */) {
const [threshold] = readVarInt(packet.data)
conn.compressionThreshold = threshold
conn.compressionEnabled = threshold >= 0
} else if (packet.id === 0x02 && !conn.loggedIn) {
conn.loggedIn = true // Login Success
} else if (
// Keep Alive (clientbound)
(packet.id === 0x1f && is1164 && !is117) ||
(packet.id === 0x21 && is117 && !is119) ||
(packet.id === 0x1e && is119 && !is1191) ||
(packet.id === 0x20 && is1191)
) {
const id = is1191 ? 0x12 : is119 ? 0x11 : is117 ? 0x0f : 0x10
conn
.writePacket(id, packet.data)
.catch(err => conn.emit('error', err))
} else if (
// Disconnect (login) or Disconnect (play)
(packet.id === 0x00 && !conn.loggedIn) ||
(packet.id === 0x19 && conn.loggedIn && is1164 && !is117) ||
(packet.id === 0x1a && conn.loggedIn && is117 && !is119) ||
(packet.id === 0x17 && conn.loggedIn && is119 && !is1191) ||
(packet.id === 0x19 && conn.loggedIn && is1191)
) {
const [chatLength, chatVarIntLength] = readVarInt(packet.data)
conn.disconnectReason = packet.data
.slice(chatVarIntLength, chatVarIntLength + chatLength)
.toString('utf8')
} else if (packet.id === 0x04 && !conn.loggedIn) {
/* Login Plugin Request */
const [msgId] = readVarInt(packet.data)
const rs = concatPacketData([writeVarInt(msgId), false])
conn.writePacket(0x02, rs).catch(err => conn.emit('error', err))
} else if (packet.id === 0x01 && !conn.loggedIn) {
/* Encryption Request */
if (!accessToken || !selectedProfile) {
conn.disconnectReason =
'{"text":"This server requires a premium account to be logged in!"}'
conn.close()
continue
}
conn.emit('packet', packet)
} else break
}
conn.emit('data', newData)
} catch (err) {
conn.emit('error', err)
handleEncryptionRequest(
packet,
accessToken,
selectedProfile,
conn,
is119,
async (secret: Buffer, response: Buffer) => {
const AES_ALG = 'aes-128-cfb8'
conn.aesDecipher = createDecipheriv(AES_ALG, secret, secret)
await conn.writePacket(0x01, response)
conn.aesCipher = createCipheriv(AES_ALG, secret, secret)
}
)
}
conn.emit('packet', packet)
} else break
}
lock.release()
}).then(() => {}, console.error)
})
conn.emit('data', newData)
} catch (err) {
conn.emit('error', err)
}
lock.release()
}).then(() => {}, console.error)
})
return conn
}

export default initiateJavaScriptConnection
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