doc/net.server.lua
author Kim Alvefur <zash@zash.se>
Sat, 23 Mar 2024 20:48:19 +0100
changeset 13465 c673ff1075bd
parent 9850 9a0da809ed4a
permissions -rw-r--r--
mod_posix: Move everything to util.startup This allows greater control over the order of events. Notably, the internal ordering between daemonization, initialization of libunbound and setup of signal handling is sensitive. libunbound starts a separate thread for processing DNS requests. If this thread is started before signal handling has been set up, it will not inherit the signal handlers and instead behave as it would have before signal handlers were set up, i.e. cause the whole process to immediately exit. libunbound is usually initialized on the first DNS request, usually triggered by an outgoing s2s connection attempt. If daemonization happens before signals have been set up, signals may not be processed at all.

-- Prosody IM
-- Copyright (C) 2014,2016 Daurnimator
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.

--luacheck: ignore

--[[
This file is a template for writing a net.server compatible backend.
]]

--[[
Read patterns (also called modes) can be one of:
  - "*a": Read as much as possible
  - "*l": Read until end of line
]]

--- Handle API
local handle_mt = {};
local handle_methods = {};
handle_mt.__index = handle_methods;

function handle_methods:set_mode(new_pattern)
end

function handle_methods:setlistener(listeners)
end

function handle_methods:setoption(option, value)
end

function handle_methods:ip()
end

function handle_methods:starttls(sslctx)
end

function handle_methods:write(data)
end

function handle_methods:close()
end

function handle_methods:pause()
end

function handle_methods:resume()
end

--[[
Returns
  - socket: the socket object underlying this handle
]]
function handle_methods:socket()
end

--[[
Returns
  - boolean: if an ssl context has been set on this handle
]]
function handle_methods:ssl()
end


--- Listeners API
local listeners = {}

--[[ connect
Called when a client socket has established a connection with it's peer
]]
function listeners.onconnect(handle)
end

--[[ incoming
Called when data is received
If reading data failed this will be called with `nil, "error message"`
]]
function listeners.onincoming(handle, buff, err)
end

--[[ status
Known statuses:
  - "ssl-handshake-complete"
]]
function listeners.onstatus(handle, status)
end

--[[ disconnect
Called when the peer has closed the connection
]]
function listeners.ondisconnect(handle)
end

--[[ drain
Called when the handle's write buffer is empty
]]
function listeners.ondrain(handle)
end

--[[ readtimeout
Called when a socket inactivity timeout occurs
]]
function listeners.onreadtimeout(handle)
end

--[[ detach: Called when other listeners are going to be removed
Allows for clean-up
]]
function listeners.ondetach(handle)
end

--- Top level functions

--[[ Returns the syscall level event mechanism in use.

Returns:
  - backend: e.g. "select", "epoll"
]]
local function get_backend()
end

--[[ Starts the event loop.

Returns:
  - "quitting"
]]
local function loop()
end

--[[ Stop a running loop()
]]
local function setquitting(quit)
end


--[[ Links to two handles together, so anything written to one is piped to the other

Arguments:
  - sender, receiver: handles to link
  - buffersize: maximum #bytes until sender will be locked
]]
local function link(sender, receiver, buffersize)
end

--[[ Binds and listens on the given address and port
If `sslctx` is given, the connecting clients will have to negotiate an SSL session

Arguments:
  - address: address to bind to, may be "*" to bind all addresses. will be resolved if it is a string.
  - port: port to bind (as number)
  - listeners: a table of listeners
  - pattern: the read pattern
  - sslctx: is a valid luasec constructor

Returns:
  - handle
  - nil, "an error message": on failure (e.g. out of file descriptors)
]]
local function addserver(address, port, listeners, pattern, sslctx)
end

--[[ Binds and listens on the given address and port
Mostly the same as addserver but with all optional arguments in a table

Arguments:
  - address: address to bind to, may be "*" to bind all addresses. will be resolved if it is a string.
  - port: port to bind (as number)
  - listeners: a table of listeners
	- config: table of extra settings
		- read_size: the amount of bytes to read or a read pattern
		- tls_ctx: is a valid luasec constructor
		- tls_direct: boolean true for direct TLS, false (or nil) for starttls

Returns:
  - handle
  - nil, "an error message": on failure (e.g. out of file descriptors)
]]
local function listen(address, port, listeners, config)
end


--[[ Wraps a lua-socket socket client socket in a handle.
The socket must be already connected to the remote end.
If `sslctx` is given, a SSL session will be negotiated before listeners are called.

Arguments:
  - socket: the lua-socket object to wrap
  - ip: returned by `handle:ip()`
  - port:
  - listeners: a table of listeners
  - pattern: the read pattern
  - sslctx: is a valid luasec constructor
  - typ: the socket type, one of:
	  - "tcp"
	  - "tcp6"
	  - "udp"

Returns:
  - handle, socket
  - nil, "an error message": on failure (e.g. )
]]
local function wrapclient(socket, ip, serverport, listeners, pattern, sslctx)
end

--[[ Connects to the given address and port
If `sslctx` is given, a SSL session will be negotiated before listeners are called.

Arguments:
  - address: address to connect to. will be resolved if it is a string.
  - port: port to connect to (as number)
  - listeners: a table of listeners
  - pattern: the read pattern
  - sslctx: is a valid luasec constructor
  - typ: the socket type, one of:
	  - "tcp"
	  - "tcp6"
	  - "udp"

Returns:
  - handle
  - nil, "an error message": on failure (e.g. out of file descriptors)
]]
local function addclient(address, port, listeners, pattern, sslctx, typ)
end

--[[ Close all handles
]]
local function closeall()
end

--[[ The callback should be called after `delay` seconds.
The callback should be called with the time at the point of firing.
If the callback returns a number, it should be called again after that many seconds.

Arguments:
  - delay: number of seconds to wait
  - callback: function to call.
]]
local function add_task(delay, callback)
end

--[[ Adds a handler for when a signal is fired.
Optional to implement
callback does not take any arguments

Arguments:
  - signal_id: the signal id (as number) to listen for
  - handler: callback
]]
local function hook_signal(signal_id, handler)
end

--[[ Adds a low-level FD watcher
Arguments:
-   fd_number: A non-negative integer representing a file descriptor or
    object with a :getfd() method returning one
-   on_readable: Optional callback for when the FD is readable
-   on_writable: Optional callback for when the FD is writable

Returns:
-   net.server handle
]]
local function watchfd(fd_number, on_readable, on_writable)
end

return {
	get_backend = get_backend;
	loop = loop;
	setquitting = setquitting;
	link = link;
	addserver = addserver;
	wrapclient = wrapclient;
	addclient = addclient;
	closeall = closeall;
	hook_signal = hook_signal;
	watchfd = watchfd;
	listen = listen;
}