2 -- Implementation of the DCC protocol
5 local irc = require 'irc'
6 local ctcp = require 'irc.ctcp'
7 local c = ctcp._ctcp_quote
8 local irc_debug = require 'irc.debug'
9 local misc = require 'irc.misc'
10 local socket = require 'socket'
11 local coroutine = require 'coroutine'
12 local io = require 'io'
13 local string = require 'string'
17 -- This module implements the DCC protocol. File transfers (DCC SEND) are
18 -- handled, but DCC CHAT is not, as of yet.
26 -- private functions {{{
29 -- Prints a debug message about DCC events similar to irc.debug.warn, etc.
30 -- @param msg Debug message
31 local function debug_dcc(msg)
32 irc_debug._message("DCC", msg, "\027[0;32m")
38 -- Sends a file to a remote user, after that user has accepted our DCC SEND
40 -- @param sock Socket to send the file on
41 -- @param file Lua file object corresponding to the file we want to send
42 -- @param packet_size Size of the packets to send the file in
43 local function send_file(sock, file, packet_size)
46 local packet = file:read(packet_size)
47 if not packet then break end
48 bytes = bytes + packet:len()
52 sock:send(packet, index)
53 local new_bytes, err = sock:receive(4)
55 if err == "timeout" then
62 new_bytes = misc._int_to_str(new_bytes)
65 if new_bytes ~= bytes then
66 index = packet_size - bytes + new_bytes + 1
74 debug_dcc("File completely sent")
77 irc._unregister_socket(sock, 'w')
84 -- Handle the connection attempt by a remote user to get our file. Basically
85 -- just swaps out the server socket we were listening on for a client socket
86 -- that we can send data on
87 -- @param ssock Server socket that the remote user connected to
88 -- @param file Lua file object corresponding to the file we want to send
89 -- @param packet_size Size of the packets to send the file in
90 local function handle_connect(ssock, file, packet_size)
91 debug_dcc("Offer accepted, beginning to send")
92 packet_size = packet_size or 1024
93 local sock = ssock:accept()
96 irc._unregister_socket(ssock, 'r')
97 irc._register_socket(sock, 'w',
98 coroutine.wrap(function(s)
99 return send_file(s, file, packet_size)
107 -- Accepts a file from a remote user which has offered it to us.
108 -- @param sock Socket to receive the file on
109 -- @param file Lua file object corresponding to the file we want to save
110 -- @param packet_size Size of the packets to receive the file in
111 local function accept_file(sock, file, packet_size)
114 local packet, err, partial_packet = sock:receive(packet_size)
115 if not packet and err == "timeout" then packet = partial_packet end
116 if not packet then break end
117 if packet:len() == 0 then break end
118 bytes = bytes + packet:len()
119 sock:send(misc._str_to_int(bytes))
121 coroutine.yield(true)
123 debug_dcc("File completely received")
126 irc._unregister_socket(sock, 'r')
132 -- internal functions {{{
135 -- Accepts a file offer from a remote user. Called when the on_dcc callback
137 -- @param filename Name to save the file as
138 -- @param address IP address of the remote user in low level int form
139 -- @param port Port to connect to at the remote user
140 -- @param packet_size Size of the packets the remote user will be sending
141 function _accept(filename, address, port, packet_size)
142 debug_dcc("Accepting a DCC SEND request from " ..
143 misc._ip_int_to_str(address) .. ":" .. port)
144 packet_size = packet_size or 1024
145 local sock = base.assert(socket.tcp())
146 base.assert(sock:connect(misc._ip_int_to_str(address), port))
148 local file = base.assert(io.open(misc._get_unique_filename(filename), "w"))
149 irc._register_socket(sock, 'r',
150 coroutine.wrap(function(s)
151 return accept_file(s, file, packet_size)
157 -- public functions {{{
160 -- Offers a file to a remote user.
161 -- @param nick User to offer the file to
162 -- @param filename Filename to offer
163 -- @param port Port to accept connections on (optional, defaults to
164 -- choosing an available port between FIRST_PORT and LAST_PORT
166 function send(nick, filename, port)
167 port = port or FIRST_PORT
170 sock = base.assert(socket.tcp())
171 err, msg = sock:bind('*', port)
173 until msg ~= "address already in use" and port <= LAST_PORT + 1
174 base.assert(err, msg)
175 base.assert(sock:listen(1))
176 local ip = misc._ip_str_to_int(irc.get_ip())
177 local file = base.assert(io.open(filename))
178 local size = file:seek("end")
180 irc._register_socket(sock, 'r',
181 coroutine.wrap(function(s)
182 return handle_connect(s, file)
184 filename = misc._basename(filename)
185 if filename:find(" ") then filename = '"' .. filename .. '"' end
186 debug_dcc("Offering " .. filename .. " to " .. nick .. " from " ..
187 irc.get_ip() .. ":" .. port - 1)
188 irc.send("PRIVMSG", nick, c("DCC", "SEND", filename, ip, port - 1, size))