-- (C) 2011, Marco Cirillo (LW.Org)

module:set_global()

local guard_blockall = module:get_option_set("host_guard_blockall", {})

local guard_ball_wl = module:get_option_set("host_guard_blockall_exceptions", {})

local guard_protect = module:get_option_set("host_guard_selective", {})

local guard_block_bl = module:get_option_set("host_guard_blacklist", {})

local s2smanager = require "core.s2smanager";

local config = require "core.configmanager";

local nameprep = require "util.encodings".stringprep.nameprep;

local _make_connect = s2smanager.make_connect;

function s2smanager.make_connect(session, connect_host, connect_port)

  if not session.s2sValidation then

    if guard_blockall:contains(session.from_host) and not guard_ball_wl:contains(session.to_host) or

       guard_block_bl:contains(session.to_host) and guard_protect:contains(session.from_host) then

         module:log("error", "remote service %s attempted to access restricted host %s", session.to_host, session.from_host);

         s2smanager.destroy_session(session, "You're not authorized, good bye.");

         return false;

    end

  end

  return _make_connect(session, connect_host, connect_port);

end

local _stream_opened = s2smanager.streamopened;

function s2smanager.streamopened(session, attr)

  local host = attr.to and nameprep(attr.to);

  local from = attr.from and nameprep(attr.from);

    if not from then

      session.s2sValidation = false;

    else

      session.s2sValidation = true;

    end

    if guard_blockall:contains(host) and not guard_ball_wl:contains(from) or

       guard_block_bl:contains(from) and guard_protect:contains(host) then

         module:log("error", "remote service %s attempted to access restricted host %s", from, host);

         session:close({condition = "policy-violation", text = "You're not authorized, good bye."});

         return false;

    end

    _stream_opened(session, attr);

end

local function sdr_hook (event)

	local origin, stanza = event.origin, event.stanza;

	if origin.type == "s2sin" or origin.type == "s2sin_unauthed" then

	   if guard_blockall:contains(stanza.attr.to) and not guard_ball_wl:contains(stanza.attr.from) or

	      guard_block_bl:contains(stanza.attr.from) and guard_protect:contains(stanza.attr.to) then

                module:log("error", "remote service %s attempted to access restricted host %s", stanza.attr.from, stanza.attr.to);

                origin:close({condition = "policy-violation", text = "You're not authorized, good bye."});

                return false;

           end

        end

	return nil;

end

local function handle_activation (host)

	if guard_blockall:contains(host) or guard_protect:contains(host) then

		if hosts[host] and hosts[host].events then

			hosts[host].events.add_handler("stanza/jabber:server:dialback:result", sdr_hook, 100);

                	module:log ("debug", "adding host protection for: "..host);

		end

	end

end

local function handle_deactivation (host)

	if guard_blockall:contains(host) or guard_protect:contains(host) then

		if hosts[host] and hosts[host].events then

			hosts[host].events.remove_handler("stanza/jabber:server:dialback:result", sdr_hook);

                	module:log ("debug", "removing host protection for: "..host);

		end

	end

end

local function reload()

	module:log ("debug", "server configuration reloaded, rehashing plugin tables...");

	guard_blockall = module:get_option_set("host_guard_blockall", {});

	guard_ball_wl = module:get_option_set("host_guard_blockall_exceptions", {});

	guard_protect = module:get_option_set("host_guard_components", {});

	guard_block_bl = module:get_option_set("host_guard_blacklist", {});

end

local function setup()

        module:log ("debug", "initializing host guard module...");

        module:hook ("component-activated", handle_activation);

        module:hook ("component-deactivated", handle_deactivation);

        module:hook ("config-reloaded", reload);

        for n,table in pairs(hosts) do

                if table.type == "component" then

                        if guard_blockall:contains(n) or guard_protect:contains(n) then

                                hosts[n].events.remove_handler("stanza/jabber:server:dialback:result", sdr_hook);

                                handle_activation(n);

                        end

                end

        end

end

if prosody.start_time then

	setup();

else

	prosody.events.add_handler("server-started", setup);

end