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";
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");
19 -- if not defined assume admin wants best compression
20 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", "compress", xmlns_compression_protocol,
40 function(session, stanza)
41 -- checking if the compression method is supported
42 local method = stanza:child_with_name("method")[1];
43 if method == "zlib" then
44 session.log("info", method.." compression selected.");
45 session.send(st.stanza("compressed", {xmlns=xmlns_compression_protocol}));
46 session:reset_stream();
48 -- create deflate and inflate streams
49 local status, deflate_stream = pcall(zlib.deflate, compression_level);
50 if status == false then
51 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed");
52 session.send(error_st);
53 session:log("error", "Failed to create zlib.deflate filter.");
54 module:log("error", inflate_stream);
58 local status, inflate_stream = pcall(zlib.inflate);
59 if status == false then
60 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed");
61 session.send(error_st);
62 session:log("error", "Failed to create zlib.deflate filter.");
63 module:log("error", inflate_stream);
67 -- setup compression for session.w
68 local old_send = session.send;
70 session.send = function(t)
71 local status, compressed, eof = pcall(deflate_stream, tostring(t), 'sync');
72 if status == false then
74 condition = "undefined-condition";
76 extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed");
78 module:log("error", compressed);
84 -- setup decompression for session.data
85 local function setup_decompression(session)
86 local old_data = session.data
87 session.data = function(conn, data)
88 local status, decompressed, eof = pcall(inflate_stream, data);
89 if status == false then
91 condition = "undefined-condition";
93 extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed");
95 module:log("error", compressed);
98 old_data(conn, decompressed);
101 setup_decompression(session);
103 local session_reset_stream = session.reset_stream;
104 session.reset_stream = function(session)
105 session_reset_stream(session);
106 setup_decompression(session);
109 session.compressed = true;
111 session.log("info", method.." compression selected. But we don't support it.");
112 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method");
113 session.send(error_st);