+module:hook("stanza/http://jabber.org/protocol/compress:compressed", function(event)
+ local session = event.origin;
+
+ if session.type == "s2sout_unauthed" or session.type == "s2sout" then
+ session.log("debug", "Activating compression...")
+ -- create deflate and inflate streams
+ local deflate_stream = get_deflate_stream(session);
+ if not deflate_stream then return true; end
+
+ local inflate_stream = get_inflate_stream(session);
+ if not inflate_stream then return true; end
+
+ -- setup compression for session.w
+ setup_compression(session, deflate_stream);
+
+ -- setup decompression for session.data
+ setup_decompression(session, inflate_stream);
+ session:reset_stream();
+ local default_stream_attr = {xmlns = "jabber:server", ["xmlns:stream"] = "http://etherx.jabber.org/streams",
+ ["xmlns:db"] = 'jabber:server:dialback', version = "1.0", to = session.to_host, from = session.from_host};
+ session.sends2s("<?xml version='1.0'?>");
+ session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag());
+ session.compressed = true;
+ return true;
+ end
+end);
+
+module:hook("stanza/http://jabber.org/protocol/compress:compress", function(event)
+ local session, stanza = event.origin, event.stanza;
+
+ if session.type == "c2s" or session.type == "s2sin" or session.type == "c2s_unauthed" or session.type == "s2sin_unauthed" then
+ -- fail if we are already compressed
+ if session.compressed then
+ local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed");
+ (session.sends2s or session.send)(error_st);
+ session.log("debug", "Client tried to establish another compression layer.");
+ return true;
+ end
+
+ -- checking if the compression method is supported
+ local method = stanza:child_with_name("method");
+ method = method and (method[1] or "");
+ if method == "zlib" then
+ session.log("debug", "zlib compression enabled.");
+