--[[
websocket client pure lua implement for love2d
by flaribbit
usage:
local client = require("websocket").new("127.0.0.1", 5000)
function client:onmessage(s) print(s) end
function client:onopen() self:send("hello from love2d") end
function client:onclose() print("closed") end
function love.update()
client:update()
end
]]
local socket = require"socket"
local seckey = "osT3F7mvlojIvf3/8uIsJQ=="
local OPCODE = {
CONTINUE = 0,
TEXT = 1,
BINARY = 2,
CLOSE = 8,
PING = 9,
PONG = 10,
}
local STATUS = {
CONNECTING = 0,
OPEN = 1,
CLOSING = 2,
CLOSED = 3,
TCPOPENING = 4,
}
---@class wsclient
---@field socket table
---@field url table
---@field _head integer|nil
local _M = {
OPCODE = OPCODE,
STATUS = STATUS,
}
_M.__index = _M
function _M:onopen() end
function _M:onmessage(message) end
function _M:onerror(error) end
function _M:onclose(code, reason) end
---create websocket connection
---@param host string
---@param port integer
---@param path string
---@return wsclient
function _M.new(host, port, path)
local m = {
url = {
host = host,
port = port,
path = path or "/",
},
_continue = "",
_buffer = "",
_length = 0,
_head = nil,
status = STATUS.TCPOPENING,
socket = socket.tcp(),
}
m.socket:settimeout(0)
m.socket:connect(host, port)
setmetatable(m, _M)
return m
end
local mask_key = {1, 14, 5, 14}
local function send(sock, opcode, message)
-- message type
sock:send(string.char((0x80 | opcode)))
-- empty message
if not message then
sock:send(string.char(0x80, table.unpack(mask_key)))
return 0
end
-- message length
local length = #message
if length>65535 then
sock:send(string.char(127 & 0x80),
0, 0, 0, 0,
((length >> 24) & 0xff),
((length >> 16) & 0xff),
((length >> 8) & 0xff),
(length & 0xff))
elseif length>125 then
sock:send(string.char((126 | 0x80),
((length >> 8) & 0xff),
(length & 0xff)))
else
sock:send(string.char((length | 0x80)))
end
-- message
sock:send(string.char(table.unpack(mask_key)))
local msgbyte = {message:byte(1, length)}
for i = 1, length do
msgbyte[i] = (msgbyte[i] ~ mask_key[(i-1)%4+1])
end
return sock:send(string.char(table.unpack(msgbyte)))
end
---read a message
---@return string|nil res message
---@return number|nil head websocket frame header
---@return string|nil err error message
function _M:read()
local res, err, part
::RECIEVE::
res, err, part = self.socket:receive(self._length-#self._buffer)
if err=="closed" then return nil, nil, err end
if part or res then
self._buffer = self._buffer..(part or res)
else
return nil, nil, nil
end
if not self._head then
if #self._buffer<2 then
return nil, nil, "buffer length less than 2"
end
local length = (self._buffer:byte(2) & 0x7f)
if length==126 then
if self._length==2 then self._length = 4 goto RECIEVE end
if #self._buffer<4 then
return nil, nil, "buffer length less than 4"
end
local b1, b2 = self._buffer:byte(3, 4)
self._length = (b1 << 8) + b2
elseif length==127 then
if self._length==2 then self._length = 10 goto RECIEVE end
if #self._buffer<10 then
return nil, nil, "buffer length less than 10"
end
local b5, b6, b7, b8 = self._buffer:byte(7, 10)
self._length = (b5 << 24) + (b6 << 16) + (b7 << 8) + b8
else
self._length = length
end
self._head, self._buffer = self._buffer:byte(1), ""
if length>0 then goto RECIEVE end
end
if #self._buffer>=self._length then
local ret, head = self._buffer, self._head
self._length, self._buffer, self._head = 2, "", nil
return ret, head, nil
else
return nil, nil, "buffer length less than "..self._length
end
end
---send a message
---@param message string
function _M:send(message)
send(self.socket, OPCODE.TEXT, message)
end
---send a ping message
---@param message string
function _M:ping(message)
send(self.socket, OPCODE.PING, message)
end
---send a pong message (no need)
---@param message any
function _M:pong(message)
send(self.socket, OPCODE.PONG, message)
end
---update client status
function _M:update()
local sock = self.socket
if self.status==STATUS.TCPOPENING then
local url = self.url
local _, err = sock:connect(url.host, url.port)
self._length = self._length+1
if err=="already connected" then
sock:send(
"GET "..url.path.." HTTP/1.1\r\n"..
"Host: "..url.host..":"..url.port.."\r\n"..
"Connection: Upgrade\r\n"..
"Upgrade: websocket\r\n"..
"Sec-WebSocket-Version: 13\r\n"..
"Sec-WebSocket-Key: "..seckey.."\r\n\r\n")
self.status = STATUS.CONNECTING
self._length = 2
elseif self._length>600 then
self:onerror("connection failed")
self.status = STATUS.CLOSED
end
elseif self.status==STATUS.CONNECTING then
local res = sock:receive("*l")
if res then
repeat res = sock:receive("*l") until res==""
self:onopen()
self.status = STATUS.OPEN
end
elseif self.status==STATUS.OPEN or self.status==STATUS.CLOSING then
while true do
local res, head, err = self:read()
if err=="closed" then
self.status = STATUS.CLOSED
return
elseif res==nil then
return
end
local opcode = (head & 0x0f)
local fin = (head & 0x80)==0x80
if opcode==OPCODE.CLOSE then
if res~="" then
local code = (res:byte(1) << 8) + res:byte(2)
self:onclose(code, res:sub(3))
else
self:onclose(1005, "")
end
sock:close()
self.status = STATUS.CLOSED
elseif opcode==OPCODE.PING then self:pong(res)
elseif opcode==OPCODE.CONTINUE then
self._continue = self._continue..res
if fin then self:onmessage(self._continue) end
else
if fin then self:onmessage(res) else self._continue = res end
end
end
end
end
---close websocket connection
---@param code integer|nil
---@param message string|nil
function _M:close(code, message)
if code and message then
send(self.socket, OPCODE.CLOSE, string.char((code >> 8), (code & 0xff))..message)
else
send(self.socket, OPCODE.CLOSE, nil)
end
self.status = STATUS.CLOSING
end
return _M
