websocket client pure lua implement for love2d

Zframework/websocket.lua

@@ -0,0 +1,135 @@
+--[[
+websocket client pure lua implement for love2d
+by flaribbit
+
+usage:
+    local client = require("websocket").new()
+    client:connect("127.0.0.1", 5000)
+    client:settimeout(0)
+    client:send("hello from love2d")
+    print(client:read())
+    client:close()
+]]
+
+local socket = require"socket"
+local bit = require"bit"
+local band = bit.band
+local bor = bit.bor
+local bxor = bit.bxor
+local shl = bit.lshift
+local shr = bit.rshift
+
+-- local log_debug = print
+local log_debug = function()end
+local b2s = function(b)return b and"true"or"false"end
+
+local OPCODES = {
+    ["CONTINUE"]=0,
+    ["TEXT"]    =1,
+    ["BINARY"]  =2,
+    ["CLOSE"]   =8,
+    ["PING"]    =9,
+    ["PONG"]    =10,
+}
+
+local _M = {
+    OPCODES = OPCODES,
+}
+_M.__index = _M
+
+_M.new = function()
+    local m = {}
+    setmetatable(m, _M)
+    return m
+end
+
+_M.connect = function(self, host, port, path)
+    local socket = socket.tcp()
+    self.socket = socket
+    local res, err = socket:connect(host, port)
+    if res~=1 then
+        return res, err
+    end
+    log_debug("[handshake] connected")
+    -- WebSocket handshake
+    local seckey = "osT3F7mvlojIvf3/8uIsJQ=="
+    path = path or "/"
+    res, err = socket:send("GET "..path.." HTTP/1.1\r\nHost: "..host..":"..port.."\r\nConnection: Upgrade\r\nUpgrade: websocket\r\nSec-WebSocket-Version: 13\r\nSec-WebSocket-Key: "..seckey.."\r\n\r\n")
+    repeat
+        res = socket:receive("*l")
+    until res==""
+    log_debug("[handshake] succeed")
+end
+
+_M.send = function(self, message)
+    local socket = self.socket
+    local mask_key = {1, 14, 5, 14}
+    -- message type
+    socket:send(string.char(bor(0x80, OPCODES.BINARY)))
+    -- length
+    local length = #message
+    log_debug("[encode] message length: "..length)
+    if length>65535 then
+        socket:send(string.char(bor(127, 0x80), 0, 0, 0, 0,
+            band(shr(length, 24), 0xff),
+            band(shr(length, 16), 0xff),
+            band(shr(length, 8), 0xff),
+            band(length, 0xff)))
+    elseif length>125 then
+        socket:send(string.char(bor(126, 0x80),
+            band(shr(length, 8), 0xff),
+            band(length, 0xff)))
+    else
+        socket:send(string.char(bor(length, 0x80)))
+    end
+    log_debug("[encode] masking")
+    socket:send(string.char(unpack(mask_key)))
+    local msgbyte = {message:byte(1, length)}
+    for i = 1, length do
+        msgbyte[i] = bxor(msgbyte[i], mask_key[(i-1)%4+1])
+    end
+    socket:send(string.char(unpack(msgbyte)))
+    log_debug("[encode] end")
+end
+
+_M.read = function(self)
+    -- byte 0-1
+    local socket = self.socket
+    local res, err = socket:receive(2)
+    if res==nil then
+        return res, err
+    end
+    local byte = res:byte()
+    local flag_FIN = byte>=0x80
+    local OPCODE = band(byte, 0x0f)
+    byte = res:byte(2)
+    local flag_MASK = byte>=0x80
+    log_debug("[decode] FIN="..b2s(flag_FIN)..", OPCODE="..OPCODE..", MASK="..b2s(flag_MASK))
+    -- length
+    local length = band(byte, 0x7f)
+    if length==126 then
+        res = socket:receive(2)
+        local b1, b2 = res:byte(1, 2)
+        length = shl(b1, 8) + b2
+    elseif length==127 then
+        res = socket:receive(8)
+        local b = {res:byte(1, 8)}
+        length = shl(b[5], 32) + shl(b[6], 24) + shl(b[7], 8) + b[8]
+    end
+    log_debug("[decode] message length: "..length)
+    -- data
+    res = socket:receive(length)
+    log_debug("[decode] string length: "..#res)
+    log_debug("[decode] end")
+    return res
+end
+
+_M.close = function(self)
+    self.socket:close()
+end
+
+_M.settimeout = function(self, t)
+    self.socket:settimeout(t)
+end
+
+return _M