File

net/connect.lua @ 10823:b8be600803ee

mod_csi_simple: Add comment highlighting that XEP-0353 is experimental To make it easier to find implemented Experimental XEPs later. Also at the time of this commit it has been Proposed as mentinoed in the comment but hopefully that will be resolved soon.
author Kim Alvefur <zash@zash.se>
date Sat, 09 May 2020 01:01:03 +0200
parent 10623:f51c88baeb8a
child 10945:2edb72ef312a
line wrap: on
line source

local server = require "net.server";
local log = require "util.logger".init("net.connect");
local new_id = require "util.id".short;

-- TODO Respect use_ipv4, use_ipv6
-- TODO #1246 Happy Eyeballs
-- FIXME RFC 6724
-- FIXME Error propagation from resolvers doesn't work
-- FIXME #1428 Reuse DNS resolver object between service and basic resolver
-- FIXME #1429 Close DNS resolver object when done

local pending_connection_methods = {};
local pending_connection_mt = {
	__name = "pending_connection";
	__index = pending_connection_methods;
	__tostring = function (p)
		return "<pending connection "..p.id.." to "..tostring(p.target_resolver.hostname)..">";
	end;
};

function pending_connection_methods:log(level, message, ...)
	log(level, "[pending connection %s] "..message, self.id, ...);
end

-- pending_connections_map[conn] = pending_connection
local pending_connections_map = {};

local pending_connection_listeners = {};

local function attempt_connection(p)
	p:log("debug", "Checking for targets...");
	if p.conn then
		pending_connections_map[p.conn] = nil;
		p.conn = nil;
	end
	p.target_resolver:next(function (conn_type, ip, port, extra)
		if not conn_type then
			-- No more targets to try
			p:log("debug", "No more connection targets to try");
			if p.listeners.onfail then
				p.listeners.onfail(p.data, p.last_error or "unable to resolve service");
			end
			return;
		end
		p:log("debug", "Next target to try is %s:%d", ip, port);
		local conn, err = server.addclient(ip, port, pending_connection_listeners, p.options.pattern or "*a", p.options.sslctx, conn_type, extra);
		if not conn then
			log("debug", "Connection attempt failed immediately: %s", err);
			p.last_error = err or "unknown reason";
			return attempt_connection(p);
		end
		p.conn = conn;
		pending_connections_map[conn] = p;
	end);
end

function pending_connection_listeners.onconnect(conn)
	local p = pending_connections_map[conn];
	if not p then
		log("warn", "Successful connection, but unexpected! Closing.");
		conn:close();
		return;
	end
	pending_connections_map[conn] = nil;
	p:log("debug", "Successfully connected");
	conn:setlistener(p.listeners, p.data);
	return p.listeners.onconnect(conn);
end

function pending_connection_listeners.ondisconnect(conn, reason)
	local p = pending_connections_map[conn];
	if not p then
		log("warn", "Failed connection, but unexpected!");
		return;
	end
	p.last_error = reason or "unknown reason";
	p:log("debug", "Connection attempt failed: %s", p.last_error);
	attempt_connection(p);
end

local function connect(target_resolver, listeners, options, data)
	local p = setmetatable({
		id = new_id();
		target_resolver = target_resolver;
		listeners = assert(listeners);
		options = options or {};
		data = data;
	}, pending_connection_mt);

	p:log("debug", "Starting connection process");
	attempt_connection(p);
end

return {
	connect = connect;
};