IMPORTANT: due to a drive failure, as of 13-Mar-2021, the Mercurial repository had to be re-mirrored, which changed every commit SHA. The old SHAs and trees are backed up in the vault branches. Please migrate to the new branches as soon as you can.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
prosody/plugins/mod_s2s/s2sout.lib.lua

335 lines
11 KiB

-- 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.
--
--- Module containing all the logic for connecting to a remote server
local portmanager = require "core.portmanager";
local wrapclient = require "net.server".wrapclient;
local initialize_filters = require "util.filters".initialize;
local idna_to_ascii = require "util.encodings".idna.to_ascii;
local new_ip = require "util.ip".new_ip;
local rfc6724_dest = require "util.rfc6724".destination;
local socket = require "socket";
local adns = require "net.adns";
local dns = require "net.dns";
local t_insert, t_sort, ipairs = table.insert, table.sort, ipairs;
local local_addresses = require "util.net".local_addresses;
local s2s_destroy_session = require "core.s2smanager".destroy_session;
local default_mode = module:get_option("network_default_read_size", 4096);
local log = module._log;
local sources = {};
local has_ipv4, has_ipv6;
local dns_timeout = module:get_option_number("dns_timeout", 15);
dns.settimeout(dns_timeout);
local s2sout = {};
local s2s_listener;
function s2sout.set_listener(listener)
s2s_listener = listener;
end
local function compare_srv_priorities(a,b)
return a.priority < b.priority or (a.priority == b.priority and a.weight > b.weight);
end
function s2sout.initiate_connection(host_session)
initialize_filters(host_session);
host_session.version = 1;
host_session.resolver = adns.resolver();
-- Kick the connection attempting machine into life
if not s2sout.attempt_connection(host_session) then
-- Intentionally not returning here, the
-- session is needed, connected or not
s2s_destroy_session(host_session);
end
if not host_session.sends2s then
-- A sends2s which buffers data (until the stream is opened)
-- note that data in this buffer will be sent before the stream is authed
-- and will not be ack'd in any way, successful or otherwise
local buffer;
function host_session.sends2s(data)
if not buffer then
buffer = {};
host_session.send_buffer = buffer;
end
log("debug", "Buffering data on unconnected s2sout to %s", host_session.to_host);
buffer[#buffer+1] = data;
log("debug", "Buffered item %d: %s", #buffer, data);
end
end
end
function s2sout.attempt_connection(host_session, err)
local to_host = host_session.to_host;
local connect_host, connect_port = to_host and idna_to_ascii(to_host), 5269;
if not connect_host then
return false;
end
if not err then -- This is our first attempt
log("debug", "First attempt to connect to %s, starting with SRV lookup...", to_host);
host_session.connecting = true;
host_session.resolver:lookup(function (answer)
local srv_hosts = { answer = answer };
host_session.srv_hosts = srv_hosts;
host_session.srv_choice = 0;
host_session.connecting = nil;
if answer and #answer > 0 then
log("debug", "%s has SRV records, handling...", to_host);
for _, record in ipairs(answer) do
t_insert(srv_hosts, record.srv);
end
if #srv_hosts == 1 and srv_hosts[1].target == "." then
log("debug", "%s does not provide a XMPP service", to_host);
s2s_destroy_session(host_session, err); -- Nothing to see here
return;
end
t_sort(srv_hosts, compare_srv_priorities);
local srv_choice = srv_hosts[1];
host_session.srv_choice = 1;
if srv_choice then
connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
log("debug", "Best record found, will connect to %s:%d", connect_host, connect_port);
end
else
log("debug", "%s has no SRV records, falling back to A/AAAA", to_host);
end
-- Try with SRV, or just the plain hostname if no SRV
local ok, err = s2sout.try_connect(host_session, connect_host, connect_port);
if not ok then
if not s2sout.attempt_connection(host_session, err) then
-- No more attempts will be made
s2s_destroy_session(host_session, err);
end
end
end, "_xmpp-server._tcp."..connect_host..".", "SRV");
return true; -- Attempt in progress
elseif host_session.ip_hosts then
return s2sout.try_connect(host_session, connect_host, connect_port, err);
elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
host_session.srv_choice = host_session.srv_choice + 1;
local srv_choice = host_session.srv_hosts[host_session.srv_choice];
connect_host, connect_port = srv_choice.target or to_host, srv_choice.port or connect_port;
host_session.log("info", "Connection failed (%s). Attempt #%d: This time to %s:%d", err, host_session.srv_choice, connect_host, connect_port);
else
host_session.log("info", "Failed in all attempts to connect to %s", host_session.to_host);
-- We're out of options
return false;
end
if not (connect_host and connect_port) then
-- Likely we couldn't resolve DNS
log("warn", "Hmm, we're without a host (%s) and port (%s) to connect to for %s, giving up :(", connect_host, connect_port, to_host);
return false;
end
return s2sout.try_connect(host_session, connect_host, connect_port);
end
function s2sout.try_next_ip(host_session)
host_session.connecting = nil;
host_session.ip_choice = host_session.ip_choice + 1;
local ip = host_session.ip_hosts[host_session.ip_choice];
local ok, err= s2sout.make_connect(host_session, ip.ip, ip.port);
if not ok then
if not s2sout.attempt_connection(host_session, err or "closed") then
err = err and (": "..err) or "";
s2s_destroy_session(host_session, "Connection failed"..err);
end
end
end
function s2sout.try_connect(host_session, connect_host, connect_port, err)
host_session.connecting = true;
if not err then
local IPs = {};
host_session.ip_hosts = IPs;
local handle4, handle6;
local have_other_result = not(has_ipv4) or not(has_ipv6) or false;
if has_ipv4 then
handle4 = host_session.resolver:lookup(function (reply, err)
handle4 = nil;
if reply and reply[#reply] and reply[#reply].a then
for _, ip in ipairs(reply) do
log("debug", "DNS reply for %s gives us %s", connect_host, ip.a);
IPs[#IPs+1] = new_ip(ip.a, "IPv4");
end
elseif err then
log("debug", "Error in DNS lookup: %s", err);
end
if have_other_result then
if #IPs > 0 then
rfc6724_dest(host_session.ip_hosts, sources);
for i = 1, #IPs do
IPs[i] = {ip = IPs[i], port = connect_port};
end
host_session.ip_choice = 0;
s2sout.try_next_ip(host_session);
else
log("debug", "DNS lookup failed to get a response for %s", connect_host);
host_session.ip_hosts = nil;
if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
log("debug", "No other records to try for %s - destroying", host_session.to_host);
err = err and (": "..err) or "";
s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
end
end
else
have_other_result = true;
end
end, connect_host, "A", "IN");
else
have_other_result = true;
end
if has_ipv6 then
handle6 = host_session.resolver:lookup(function (reply, err)
handle6 = nil;
if reply and reply[#reply] and reply[#reply].aaaa then
for _, ip in ipairs(reply) do
log("debug", "DNS reply for %s gives us %s", connect_host, ip.aaaa);
IPs[#IPs+1] = new_ip(ip.aaaa, "IPv6");
end
elseif err then
log("debug", "Error in DNS lookup: %s", err);
end
if have_other_result then
if #IPs > 0 then
rfc6724_dest(host_session.ip_hosts, sources);
for i = 1, #IPs do
IPs[i] = {ip = IPs[i], port = connect_port};
end
host_session.ip_choice = 0;
s2sout.try_next_ip(host_session);
else
log("debug", "DNS lookup failed to get a response for %s", connect_host);
host_session.ip_hosts = nil;
if not s2sout.attempt_connection(host_session, "name resolution failed") then -- Retry if we can
log("debug", "No other records to try for %s - destroying", host_session.to_host);
err = err and (": "..err) or "";
s2s_destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
end
end
else
have_other_result = true;
end
end, connect_host, "AAAA", "IN");
else
have_other_result = true;
end
return true;
elseif host_session.ip_hosts and #host_session.ip_hosts > host_session.ip_choice then -- Not our first attempt, and we also have IPs left to try
s2sout.try_next_ip(host_session);
else
host_session.ip_hosts = nil;
if not s2sout.attempt_connection(host_session, "out of IP addresses") then -- Retry if we can
log("debug", "No other records to try for %s - destroying", host_session.to_host);
err = err and (": "..err) or "";
s2s_destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't
return false;
end
end
return true;
end
function s2sout.make_connect(host_session, connect_host, connect_port)
(host_session.log or log)("debug", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port);
-- Reset secure flag in case this is another
-- connection attempt after a failed STARTTLS
host_session.secure = nil;
host_session.encrypted = nil;
local conn, handler;
local proto = connect_host.proto;
if proto == "IPv4" then
conn, handler = socket.tcp();
elseif proto == "IPv6" and socket.tcp6 then
conn, handler = socket.tcp6();
else
handler = "Unsupported protocol: "..tostring(proto);
end
if not conn then
log("warn", "Failed to create outgoing connection, system error: %s", handler);
return false, handler;
end
conn:settimeout(0);
local success, err = conn:connect(connect_host.addr, connect_port);
if not success and err ~= "timeout" then
log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host.addr, connect_port, err);
return false, err;
end
conn = wrapclient(conn, connect_host.addr, connect_port, s2s_listener, default_mode);
host_session.conn = conn;
-- Register this outgoing connection so that xmppserver_listener knows about it
-- otherwise it will assume it is a new incoming connection
s2s_listener.register_outgoing(conn, host_session);
log("debug", "Connection attempt in progress...");
return true;
end
module:hook_global("service-added", function (event)
if event.name ~= "s2s" then return end
local s2s_sources = portmanager.get_active_services():get("s2s");
if not s2s_sources then
module:log("warn", "s2s not listening on any ports, outgoing connections may fail");
return;
end
for source, _ in pairs(s2s_sources) do
if source == "*" or source == "0.0.0.0" then
for _, addr in ipairs(local_addresses("ipv4", true)) do
sources[#sources + 1] = new_ip(addr, "IPv4");
end
elseif source == "::" then
for _, addr in ipairs(local_addresses("ipv6", true)) do
sources[#sources + 1] = new_ip(addr, "IPv6");
end
else
sources[#sources + 1] = new_ip(source, (source:find(":") and "IPv6") or "IPv4");
end
end
for i = 1,#sources do
if sources[i].proto == "IPv6" then
has_ipv6 = true;
elseif sources[i].proto == "IPv4" then
has_ipv4 = true;
end
end
if not (has_ipv4 or has_ipv6) then
module:log("warn", "No local IPv4 or IPv6 addresses detected, outgoing connections may fail");
end
end);
return s2sout;