File

core/sessionmanager.lua @ 13130:0b650a54ff9a

doc/hgrc-email: Example config for using 'hg email' to contribute The initial setup can be tricky if you don't know what and were settings should be added. This should maybe also go into site/doc/contributing
author Kim Alvefur <zash@zash.se>
date Wed, 07 Jun 2023 16:56:53 +0200
parent 13095:1693bd4de283
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-- Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
-- luacheck: globals prosody.full_sessions prosody.bare_sessions

local tostring, setmetatable = tostring, setmetatable;
local pairs, next= pairs, next;

local prosody, hosts = prosody, prosody.hosts;
local full_sessions = prosody.full_sessions;
local bare_sessions = prosody.bare_sessions;

local logger = require "prosody.util.logger";
local log = logger.init("sessionmanager");
local rm_load_roster = require "prosody.core.rostermanager".load_roster;
local config_get = require "prosody.core.configmanager".get;
local resourceprep = require "prosody.util.encodings".stringprep.resourceprep;
local nodeprep = require "prosody.util.encodings".stringprep.nodeprep;
local generate_identifier = require "prosody.util.id".short;
local sessionlib = require "prosody.util.session";

local initialize_filters = require "prosody.util.filters".initialize;
local gettime = require "socket".gettime;

local _ENV = nil;
-- luacheck: std none

local function new_session(conn)
	local session = sessionlib.new("c2s");
	sessionlib.set_id(session);
	sessionlib.set_logger(session);
	sessionlib.set_conn(session, conn);

	session.conntime = gettime();
	local filter = initialize_filters(session);
	local w = conn.write;

	function session.rawsend(t)
		t = filter("bytes/out", tostring(t));
		if t then
			local ret, err = w(conn, t);
			if not ret then
				session.log("debug", "Error writing to connection: %s", err);
				return false, err;
			end
		end
		return true;
	end

	session.send = function (t)
		session.log("debug", "Sending[%s]: %s", session.type, t.top_tag and t:top_tag() or t:match("^[^>]*>?"));
		if t.name then
			t = filter("stanzas/out", t);
		end
		if t then
			return session.rawsend(t);
		end
		return true;
	end
	session.ip = conn:ip();
	local conn_name = "c2s"..tostring(session):match("[a-f0-9]+$");
	session.log = logger.init(conn_name);

	return session;
end

local resting_session = { -- Resting, not dead
		destroyed = true;
		type = "c2s_destroyed";
		close = function (session)
			session.log("debug", "Attempt to close already-closed session");
		end;
		filter = function (type, data) return data; end; --luacheck: ignore 212/type
	}; resting_session.__index = resting_session;

local function retire_session(session)
	local log = session.log or log; --luacheck: ignore 431/log
	for k in pairs(session) do
		if k ~= "log" and k ~= "id" then
			session[k] = nil;
		end
	end

	function session.send(data) log("debug", "Discarding data sent to resting session: %s", data); return false; end
	function session.rawsend(data) log("debug", "Discarding data sent to resting session: %s", data); return false; end
	function session.data(data) log("debug", "Discarding data received from resting session: %s", data); end
	session.thread = { run = function (_, data) return session.data(data) end };
	return setmetatable(session, resting_session);
end

-- Update a session with a new one (transplanting connection, filters, etc.)
-- new_session should be discarded after this call returns
local function update_session(to_session, from_session)
	to_session.log("debug", "Updating with parameters from session %s", from_session.id);
	from_session.log("debug", "Session absorbed into %s", to_session.id);

	local replaced_conn = to_session.conn;
	if replaced_conn then
		to_session.conn = nil;
	end

	to_session.since = from_session.since;
	to_session.ip = from_session.ip;
	to_session.conn = from_session.conn;
	to_session.rawsend = from_session.rawsend;
	to_session.rawsend.session = to_session;
	to_session.rawsend.conn = to_session.conn;
	to_session.send = from_session.send;
	to_session.send.session = to_session;
	to_session.close = from_session.close;
	to_session.filter = from_session.filter;
	to_session.filter.session = to_session;
	to_session.filters = from_session.filters;
	to_session.send.filter = to_session.filter;
	to_session.sasl_handler = from_session.sasl_handler;
	to_session.stream = from_session.stream;
	to_session.secure = from_session.secure;
	to_session.hibernating = nil;
	to_session.resumption_counter = (to_session.resumption_counter or 0) + 1;
	from_session.log = to_session.log;
	from_session.type = to_session.type;
	-- Inform xmppstream of the new session (passed to its callbacks)
	to_session.stream:set_session(to_session);

	-- Notify modules, allowing them to copy further fields or update state
	prosody.events.fire_event("c2s-session-updated", {
		session = to_session;
		from_session = from_session;
		replaced_conn = replaced_conn;
	});

	-- Retire the session we've pulled from, to avoid two sessions on the same connection
	retire_session(from_session);
end

local function destroy_session(session, err)
	if session.destroyed then return; end

	-- Remove session/resource from user's session list
	if session.full_jid then
		local host_session = hosts[session.host];

		-- Allow plugins to prevent session destruction
		if host_session.events.fire_event("pre-resource-unbind", {session=session, error=err}) then
			(session.log or log)("debug", "Resource unbind prevented by module");
			return;
		end

		(session.log or log)("debug", "Unbinding resource for %s (%s@%s)%s",
			session.full_jid or "(unknown)", session.username or "(unknown)",
			session.host or "(unknown)", err and (": "..err) or "");

		session.destroyed = true; -- Past this point the session is DOOMED!

		host_session.sessions[session.username].sessions[session.resource] = nil;
		full_sessions[session.full_jid] = nil;

		if not next(host_session.sessions[session.username].sessions) then
			log("debug", "All resources of %s are now offline", session.username);
			host_session.sessions[session.username] = nil;
			bare_sessions[session.username..'@'..session.host] = nil;
		end

		host_session.events.fire_event("resource-unbind", {session=session, error=err});
	else
		(session.log or log)("debug", "Destroying unbound session for <%s@%s>%s",
			session.username or "(unknown)", session.host or "(unknown)",
			err and (": "..err) or "");
	end

	retire_session(session);
end

local function make_authenticated(session, username, role_name)
	username = nodeprep(username);
	if not username or #username == 0 then return nil, "Invalid username"; end
	session.username = username;
	if session.type == "c2s_unauthed" then
		session.type = "c2s_unbound";
	end

	local role;
	if role_name then
		role = hosts[session.host].authz.get_role_by_name(role_name);
	else
		role = hosts[session.host].authz.get_user_role(username);
	end
	if role then
		sessionlib.set_role(session, role);
	end
	session.log("info", "Authenticated as %s@%s [%s]", username, session.host or "(unknown)", role and role.name or "no role");
	return true;
end

-- returns true, nil on success
-- returns nil, err_type, err, err_message on failure
local function bind_resource(session, resource)
	if not session.username then return nil, "auth", "not-authorized", "Cannot bind resource before authentication"; end
	if session.resource then return nil, "cancel", "not-allowed", "Cannot bind multiple resources on a single connection"; end
	-- We don't support binding multiple resources

	local event_payload = { session = session, resource = resource };
	if hosts[session.host].events.fire_event("pre-resource-bind", event_payload) == false then
		local err = event_payload.error;
		if err then return nil, err.type, err.condition, err.text; end
		return nil, "cancel", "not-allowed";
	else
		-- In case a plugin wants to poke at it
		resource = event_payload.resource;
	end

	resource = resourceprep(resource or "", true);
	resource = resource ~= "" and resource or generate_identifier();
	--FIXME: Randomly-generated resources must be unique per-user, and never conflict with existing

	if not hosts[session.host].sessions[session.username] then
		local sessions = { sessions = {} };
		hosts[session.host].sessions[session.username] = sessions;
		bare_sessions[session.username..'@'..session.host] = sessions;
	else
		local sessions = hosts[session.host].sessions[session.username].sessions;
		if sessions[resource] then
			-- Resource conflict
			local policy = config_get(session.host, "conflict_resolve");
			local increment;
			if policy == "random" then
				resource = generate_identifier();
				increment = true;
			elseif policy == "increment" then
				increment = true; -- TODO ping old resource
			elseif policy == "kick_new" then
				return nil, "cancel", "conflict", "Resource already exists";
			else -- if policy == "kick_old" then
				sessions[resource]:close {
					condition = "conflict";
					text = "Replaced by new connection";
				};
				if not next(sessions) then
					hosts[session.host].sessions[session.username] = { sessions = sessions };
					bare_sessions[session.username.."@"..session.host] = hosts[session.host].sessions[session.username];
				end
			end
			if increment and sessions[resource] then
				local count = 1;
				while sessions[resource.."#"..count] do
					count = count + 1;
				end
				resource = resource.."#"..count;
			end
		end
	end

	session.resource = resource;
	session.full_jid = session.username .. '@' .. session.host .. '/' .. resource;
	hosts[session.host].sessions[session.username].sessions[resource] = session;
	full_sessions[session.full_jid] = session;
	if session.type == "c2s_unbound" then
		session.type = "c2s";
	end

	local err;
	session.roster, err = rm_load_roster(session.username, session.host);
	if err then
		-- FIXME: Why is all this rollback down here, instead of just doing the roster test up above?
		full_sessions[session.full_jid] = nil;
		hosts[session.host].sessions[session.username].sessions[resource] = nil;
		session.full_jid = nil;
		session.resource = nil;
		if session.type == "c2s" then
			session.type = "c2s_unbound";
		end
		if next(bare_sessions[session.username..'@'..session.host].sessions) == nil then
			bare_sessions[session.username..'@'..session.host] = nil;
			hosts[session.host].sessions[session.username] = nil;
		end
		session.log("error", "Roster loading failed: %s", err);
		return nil, "cancel", "internal-server-error", "Error loading roster";
	end

	hosts[session.host].events.fire_event("resource-bind", {session=session});

	return true;
end

local function send_to_available_resources(username, host, stanza)
	local jid = username.."@"..host;
	local count = 0;
	local user = bare_sessions[jid];
	if user then
		for _, session in pairs(user.sessions) do
			if session.presence then
				session.send(stanza);
				count = count + 1;
			end
		end
	end
	return count;
end

local function send_to_interested_resources(username, host, stanza)
	local jid = username.."@"..host;
	local count = 0;
	local user = bare_sessions[jid];
	if user then
		for _, session in pairs(user.sessions) do
			if session.interested then
				session.send(stanza);
				count = count + 1;
			end
		end
	end
	return count;
end

return {
	new_session = new_session;
	retire_session = retire_session;
	update_session = update_session;
	destroy_session = destroy_session;
	make_authenticated = make_authenticated;
	bind_resource = bind_resource;
	send_to_available_resources = send_to_available_resources;
	send_to_interested_resources = send_to_interested_resources;
};