2 -- Copyright (C) 2009 Tobias Markmann
4 -- This project is MIT/X11 licensed. Please see the
5 -- COPYING file in the source package for more information.
8 local st = require "util.stanza";
9 local zlib = require "zlib";
11 local tostring = tostring;
13 local xmlns_compression_feature = "http://jabber.org/features/compress"
14 local xmlns_compression_protocol = "http://jabber.org/protocol/compress"
15 local compression_stream_feature = st.stanza("compression", {xmlns=xmlns_compression_feature}):tag("method"):text("zlib"):up();
17 local compression_level = module:get_option("compression_level");
18 -- if not defined assume admin wants best compression
19 if compression_level == nil then compression_level = 9 end;
22 compression_level = tonumber(compression_level);
23 if not compression_level or compression_level < 1 or compression_level > 9 then
24 module:log("warn", "Invalid compression level in config: %s", tostring(compression_level));
25 module:log("warn", "Module loading aborted. Compression won't be available.");
29 module:add_event_hook("stream-features",
30 function (session, features)
31 if not session.compressed then
32 -- FIXME only advertise compression support when TLS layer has no compression enabled
33 features:add_child(compression_stream_feature);
38 -- TODO Support compression on S2S level too.
39 module:add_handler({"c2s_unauthed", "c2s"}, "compress", xmlns_compression_protocol,
40 function(session, stanza)
41 -- fail if we are already compressed
42 if session.compressed then
43 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method");
44 session.send(error_st);
45 session.log("warn", "Tried to establish another compression layer.");
49 -- checking if the compression method is supported
50 local method = stanza:child_with_name("method")[1];
51 if method == "zlib" then
52 -- create deflate and inflate streams
53 local status, deflate_stream = pcall(zlib.deflate, compression_level);
54 if status == false then
55 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed");
56 session.send(error_st);
57 session.log("error", "Failed to create zlib.deflate filter.");
58 module:log("error", "%s", tostring(deflate_stream));
62 local status, inflate_stream = pcall(zlib.inflate);
63 if status == false then
64 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed");
65 session.send(error_st);
66 session.log("error", "Failed to create zlib.inflate filter.");
67 module:log("error", "%s", tostring(inflate_stream));
71 session.log("info", method.." compression selected.");
72 session.send(st.stanza("compressed", {xmlns=xmlns_compression_protocol}));
73 session:reset_stream();
75 -- setup compression for session.w
76 local old_send = session.send;
78 session.send = function(t)
79 local status, compressed, eof = pcall(deflate_stream, tostring(t), 'sync');
80 if status == false then
82 condition = "undefined-condition";
84 extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed");
86 module:log("warn", "%s", tostring(compressed));
92 -- setup decompression for session.data
93 local function setup_decompression(session)
94 local old_data = session.data
95 session.data = function(conn, data)
96 local status, decompressed, eof = pcall(inflate_stream, data);
97 if status == false then
99 condition = "undefined-condition";
101 extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed");
103 module:log("warn", "%s", tostring(decompressed));
106 old_data(conn, decompressed);
109 setup_decompression(session);
111 local session_reset_stream = session.reset_stream;
112 session.reset_stream = function(session)
113 session_reset_stream(session);
114 setup_decompression(session);
117 session.compressed = true;
119 session.log("info", "%s compression selected, but we don't support it.", tostring(method));
120 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method");
121 session.send(error_st);