diff options
Diffstat (limited to 'plugins/mod_compression.lua')
| -rw-r--r-- | plugins/mod_compression.lua | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/plugins/mod_compression.lua b/plugins/mod_compression.lua new file mode 100644 index 00000000..f1cae737 --- /dev/null +++ b/plugins/mod_compression.lua @@ -0,0 +1,122 @@ +-- Prosody IM +-- Copyright (C) 2009 Tobias Markmann +-- +-- This project is MIT/X11 licensed. Please see the +-- COPYING file in the source package for more information. +-- + +local st = require "util.stanza"; +local zlib = require "zlib"; +local pcall = pcall; + +local xmlns_compression_feature = "http://jabber.org/features/compress" +local xmlns_compression_protocol = "http://jabber.org/protocol/compress" +local compression_stream_feature = st.stanza("compression", {xmlns=xmlns_compression_feature}):tag("method"):text("zlib"):up(); + +local compression_level = module:get_option("compression_level"); + +-- if not defined assume admin wants best compression +if compression_level == nil then compression_level = 9 end; + +compression_level = tonumber(compression_level); +if not compression_level or compression_level < 1 or compression_level > 9 then + module:log("warn", "Invalid compression level in config: %s", tostring(compression_level)); + module:log("warn", "Module loading aborted. Compression won't be available."); + return; +end + +module:add_event_hook("stream-features", + function (session, features) + if not session.compressed then + -- FIXME only advertise compression support when TLS layer has no compression enabled + features:add_child(compression_stream_feature); + end + end +); + +-- TODO Support compression on S2S level too. +module:add_handler({"c2s_unauthed", "c2s"}, "compress", xmlns_compression_protocol, + function(session, stanza) + -- fail if we are already compressed + if session.compressed then + local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method"); + session.send(error_st); + session:log("warn", "Tried to establish another compression layer."); + end + + -- checking if the compression method is supported + local method = stanza:child_with_name("method")[1]; + if method == "zlib" then + session.log("info", method.." compression selected."); + session.send(st.stanza("compressed", {xmlns=xmlns_compression_protocol})); + session:reset_stream(); + + -- create deflate and inflate streams + local status, deflate_stream = pcall(zlib.deflate, compression_level); + if status == false then + local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); + session.send(error_st); + session:log("error", "Failed to create zlib.deflate filter."); + module:log("error", deflate_stream); + return + end + + local status, inflate_stream = pcall(zlib.inflate); + if status == false then + local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); + session.send(error_st); + session:log("error", "Failed to create zlib.deflate filter."); + module:log("error", inflate_stream); + return + end + + -- setup compression for session.w + local old_send = session.send; + + session.send = function(t) + local status, compressed, eof = pcall(deflate_stream, tostring(t), 'sync'); + if status == false then + session:close({ + condition = "undefined-condition"; + text = compressed; + extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed"); + }); + module:log("warn", compressed); + return; + end + old_send(compressed); + end; + + -- setup decompression for session.data + local function setup_decompression(session) + local old_data = session.data + session.data = function(conn, data) + local status, decompressed, eof = pcall(inflate_stream, data); + if status == false then + session:close({ + condition = "undefined-condition"; + text = decompressed; + extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed"); + }); + module:log("warn", decompressed); + return; + end + old_data(conn, decompressed); + end; + end + setup_decompression(session); + + local session_reset_stream = session.reset_stream; + session.reset_stream = function(session) + session_reset_stream(session); + setup_decompression(session); + return true; + end; + session.compressed = true; + else + session.log("info", method.." compression selected. But we don't support it."); + local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method"); + session.send(error_st); + end + end +); |