view mod_component_client/mod_component_client.lua @ 4976:75b6e5df65f9

various: Improve error reporting if missing file server module on 0.12 If there is some error loading net.http.files then it would be swallowed by the pcall and then it would proceed to trying mod_http_files, which might cause unexpected behavior on 0.12 Ref #1765
author Kim Alvefur <zash@zash.se>
date Mon, 18 Jul 2022 22:47:54 +0200
parents 3e00cd4a02bc
children
line wrap: on
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--[[

mod_component_client.lua

This module turns Prosody hosts into components of other XMPP servers.

Config:

VirtualHost "component.example.com"
	component_client = {
		host = "localhost";
		port = 5347;
		secret = "hunter2";
	}


]]


local socket = require "socket"

local logger = require "util.logger";
local sha1 = require "util.hashes".sha1;
local st = require "util.stanza";

local jid_split = require "util.jid".split;
local new_xmpp_stream = require "util.xmppstream".new;
local uuid_gen = require "util.uuid".generate;

local core_process_stanza = prosody.core_process_stanza;
local hosts = prosody.hosts;

local log = module._log;

local config = module:get_option("component_client", {});
local server_host = config.host or "localhost";
local server_port = config.port or 5347;
local server_secret = config.secret or error("client_component.secret not provided");
local exit_on_disconnect = config.exit_on_disconnect;
local keepalive_interval = config.keepalive_interval or 3600;

local __conn;

local listener = {};
local session;

local xmlns_component = 'jabber:component:accept';
local stream_callbacks = { default_ns = xmlns_component };

local xmlns_xmpp_streams = "urn:ietf:params:xml:ns:xmpp-streams";

function stream_callbacks.error(session, error, data, data2)
	if session.destroyed then return; end
	module:log("warn", "Error processing component stream: %s", tostring(error));
	if error == "no-stream" then
		session:close("invalid-namespace");
	elseif error == "parse-error" then
		session.log("warn", "External component %s XML parse error: %s", tostring(session.host), tostring(data));
		session:close("not-well-formed");
	elseif error == "stream-error" then
		local condition, text = "undefined-condition";
		for child in data:children() do
			if child.attr.xmlns == xmlns_xmpp_streams then
				if child.name ~= "text" then
					condition = child.name;
				else
					text = child:get_text();
				end
				if condition ~= "undefined-condition" and text then
					break;
				end
			end
		end
		text = condition .. (text and (" ("..text..")") or "");
		session.log("info", "Session closed by remote with error: %s", text);
		session:close(nil, text);
	end
end

function stream_callbacks.streamopened(session, attr)
	-- TODO check id~=nil, from==module.host
	module:log("debug", "Sending handshake");
	local handshake = st.stanza("handshake"):text(sha1(attr.id..server_secret, true));
	session.send(handshake);
	session.notopen = nil;
end

function stream_callbacks.streamclosed(session)
	session.log("debug", "Received </stream:stream>");
	session:close();
end

module:hook("stanza/jabber:component:accept:handshake", function(event)
	session.type = "component";
	module:log("debug", "Handshake complete");
	module:fire_event("component_client/connected", {});
	return true; -- READY!
end);

module:hook("route/remote", function(event)
	return session and session.send(event.stanza);
end);

function stream_callbacks.handlestanza(session, stanza)
	-- Namespaces are icky.
	if not stanza.attr.xmlns and stanza.name == "handshake" then
		stanza.attr.xmlns = xmlns_component;
	end
	if not stanza.attr.xmlns or stanza.attr.xmlns == "jabber:client" then
		if not stanza.attr.from then
			session.log("warn", "Rejecting stanza with no 'from' address");
			session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST get a 'from' address on stanzas"));
			return;
		end
		local _, domain = jid_split(stanza.attr.to);
		if not domain then
			session.log("warn", "Rejecting stanza with no 'to' address");
			session.send(st.error_reply(stanza, "modify", "bad-request", "Components MUST get a 'to' address on stanzas"));
			return;
		elseif domain ~= session.host then
			session.log("warn", "Component received stanza with unknown 'to' address");
			session.send(st.error_reply(stanza, "cancel", "not-allowed", "Component doesn't serve this JID"));
			return;
		end
	end
	return core_process_stanza(session, stanza);
end

local stream_xmlns_attr = {xmlns='urn:ietf:params:xml:ns:xmpp-streams'};
local default_stream_attr = { ["xmlns:stream"] = "http://etherx.jabber.org/streams", xmlns = stream_callbacks.default_ns, version = "1.0", id = "" };
local function session_close(session, reason)
	if session.destroyed then return; end
	if session.conn then
		if session.notopen then
			session.send("<?xml version='1.0'?>");
			session.send(st.stanza("stream:stream", default_stream_attr):top_tag());
		end
		if reason then
			if type(reason) == "string" then -- assume stream error
				module:log("info", "Disconnecting component, <stream:error> is: %s", reason);
				session.send(st.stanza("stream:error"):tag(reason, {xmlns = 'urn:ietf:params:xml:ns:xmpp-streams' }));
			elseif type(reason) == "table" then
				if reason.condition then
					local stanza = st.stanza("stream:error"):tag(reason.condition, stream_xmlns_attr):up();
					if reason.text then
						stanza:tag("text", stream_xmlns_attr):text(reason.text):up();
					end
					if reason.extra then
						stanza:add_child(reason.extra);
					end
					module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(stanza));
					session.send(stanza);
				elseif reason.name then -- a stanza
					module:log("info", "Disconnecting component, <stream:error> is: %s", tostring(reason));
					session.send(reason);
				end
			end
		end
		session.send("</stream:stream>");
		session.conn:close();
		listener.ondisconnect(session.conn, "stream error");
	end
end

function listener.onconnect(conn)
	session = { type = "component_unauthed", conn = conn, send = function (data) return conn:write(tostring(data)); end, host = module.host };

	-- Logging functions --
	local conn_name = "jcp"..tostring(session):match("[a-f0-9]+$");
	session.log = logger.init(conn_name);
	session.close = session_close;

	session.log("info", "Outgoing Jabber component connection");

	local stream = new_xmpp_stream(session, stream_callbacks);
	session.stream = stream;

	function session.data(conn, data)
		local ok, err = stream:feed(data);
		if ok then return; end
		module:log("debug", "Received invalid XML (%s) %d bytes: %s", tostring(err), #data, data:sub(1, 300):gsub("[\r\n]+", " "):gsub("[%z\1-\31]", "_"));
		session:close("not-well-formed");
	end

	session.dispatch_stanza = stream_callbacks.handlestanza;

	session.notopen = true;
	session.send(st.stanza("stream:stream", {
		to = session.host;
		["xmlns:stream"] = 'http://etherx.jabber.org/streams';
		xmlns = xmlns_component;
	}):top_tag());

	--sessions[conn] = session;
end
function listener.onincoming(conn, data)
	--local session = sessions[conn];
	session.data(conn, data);
end
function listener.ondisconnect(conn, err)
	--local session = sessions[conn];
	if session then
		(session.log or log)("info", "component disconnected: %s (%s)", tostring(session.host), tostring(err));
		if session.on_destroy then session:on_destroy(err); end
		--sessions[conn] = nil;
		for k in pairs(session) do
			if k ~= "log" and k ~= "close" then
				session[k] = nil;
			end
		end
		session.destroyed = true;
		session = nil;
	end
	__conn = nil;
	module:log("error", "connection lost");
	module:fire_event("component_client/disconnected", { reason = err });
	if exit_on_disconnect and not prosody.shutdown_reason then
		prosody.shutdown("Shutdown by component_client disconnect", 1);
	end
end

-- send whitespace keep-alive one an hour
if keepalive_interval ~= 0 then
	module:add_timer(keepalive_interval, function()
		if __conn then
			__conn:write(" ");
		end
		return keepalive_interval;
	end);
end

function connect()
	------------------------
	-- Taken from net.http
	local conn = socket.tcp ( )
	conn:settimeout ( 10 )
	local ok, err = conn:connect ( server_host , server_port )
	if not ok and err ~= "timeout" then
		return nil, err;
	end

	local handler , conn = server.wrapclient ( conn , server_host , server_port , listener , "*a")
	__conn = handler;
	------------------------
	return true;
end
local s, err = connect();
if not s then
	listener.ondisconnect(nil, err);
end

module:hook_global("server-stopping", function(event)
	local reason = event.reason;
	if session then
		session:close{ condition = "system-shutdown", text = reason };
	end
end, 1000);