OC-PsychOS2/lib/minitel.lua

168 lines
4.5 KiB
Lua

local computer,event = computer,event
if _OSVERSION:sub(1,6) == "OpenOS" then
computer = require "computer"
event = require "event"
elseif _OSVERSION:sub(1,7) == "PsychOS" then
event = require "event"
end
local net = {}
net.mtu = 4096
net.streamdelay = 30
net.minport = 32768
net.maxport = 65535
net.openports = {}
function net.genPacketID() -- -- string -- generate a random 16-character string, for use in packet IDs
local npID = ""
for i = 1, 16 do
npID = npID .. string.char(math.random(32,126))
end
return npID
end
function net.usend(to,port,data,npID) -- string number string string -- -- send an unreliable packet to host *to* on port *port* with data *data*, optionally with the packet ID *npID*
computer.pushSignal("net_send",0,to,port,data,npID)
end
function net.rsend(to,port,data,block) -- string number string boolean -- boolean -- send a reliable packet to host *to* on port *port* with data *data*, with *block* set to true to disable blocking
local pid, stime = net.genPacketID(), computer.uptime() + net.streamdelay
computer.pushSignal("net_send",1,to,port,data,pid)
if block then return false end
repeat
_,rpid = event.pull(0.5,"net_ack")
until rpid == pid or computer.uptime() > stime
if not rpid then return false end
return true
end
-- ordered packet delivery, layer 4?
function net.send(to,port,ldata) -- string number string -- boolean -- send arbitrary data *ldata* reliably to host *to* on port *port*
local tdata = {}
if ldata:len() > net.mtu then
for i = 1, ldata:len(), net.mtu do
tdata[#tdata+1] = ldata:sub(1,net.mtu)
ldata = ldata:sub(net.mtu+1)
end
else
tdata = {ldata}
end
for k,v in ipairs(tdata) do
if not net.rsend(to,port,v) then return false end
end
return true
end
-- socket stuff, layer 5?
local function cwrite(self,data)
if self.state == "open" then
if not net.send(self.addr,self.port,data) then
self:close()
return false, "timed out"
end
end
end
local function cread(self,length)
length = length or "\n"
local rdata = ""
if type(length) == "number" then
rdata = self.rbuffer:sub(1,length)
self.rbuffer = self.rbuffer:sub(length+1)
return rdata
elseif type(length) == "string" then
if length:sub(1,2) == "*a" then
rdata = self.rbuffer
self.rbuffer = ""
return rdata
elseif length:len() == 1 then
local pre, post = self.rbuffer:match("(.-)"..length.."(.*)")
if pre and post then
self.rbuffer = post
return pre
end
return nil
end
end
end
local function socket(addr,port,sclose)
local conn = {}
conn.addr,conn.port = addr,tonumber(port)
conn.rbuffer = ""
conn.write = cwrite
conn.read = cread
conn.state = "open"
conn.sclose = sclose
local function listener(_,f,p,d)
if f == conn.addr and p == conn.port then
if d == sclose then
conn:close()
else
conn.rbuffer = conn.rbuffer .. d
end
end
end
event.listen("net_msg",listener)
function conn.close(self)
event.ignore("net_msg",listener)
conn.state = "closed"
net.rsend(addr,port,sclose)
end
return conn
end
function net.open(to,port) -- string number -- buffer -- open a socket to host *to* on port *port*
if not net.rsend(to,port,"openstream") then return false, "no ack from host" end
local st = computer.uptime()+net.streamdelay
local est = false
while true do
_,from,rport,data = event.pull("net_msg")
if to == from and rport == port then
if tonumber(data) then
est = true
end
break
end
if st < computer.uptime() then
return nil, "timed out"
end
end
if not est then
return nil, "refused"
end
data = tonumber(data)
sclose = ""
repeat
_,from,nport,sclose = event.pull("net_msg")
until from == to and nport == data
return socket(to,data,sclose)
end
function net.listen(port) -- number -- buffer -- listen for connections on port *port* in a blocking manner
repeat
_, from, rport, data = event.pull("net_msg")
until rport == port and data == "openstream"
local nport = math.random(net.minport,net.maxport)
local sclose = net.genPacketID()
net.rsend(from,rport,tostring(nport))
net.rsend(from,nport,sclose)
return socket(from,nport,sclose)
end
function net.flisten(port,listener) -- number function -- function -- run function *listener* on a connection to *port*
local function helper(_,from,rport,data)
if rport == port and data == "openstream" then
local nport = math.random(net.minport,net.maxport)
local sclose = net.genPacketID()
net.rsend(from,rport,tostring(nport))
net.rsend(from,nport,sclose)
listener(socket(from,nport,sclose))
end
end
event.listen("net_msg",helper)
return helper
end
return net