diff options
Diffstat (limited to 'plugins/mod_compression.lua')
| -rw-r--r-- | plugins/mod_compression.lua | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/plugins/mod_compression.lua b/plugins/mod_compression.lua new file mode 100644 index 00000000..92856099 --- /dev/null +++ b/plugins/mod_compression.lua @@ -0,0 +1,195 @@ +-- Prosody IM +-- Copyright (C) 2009-2012 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 tostring = tostring; + +local xmlns_compression_feature = "http://jabber.org/features/compress" +local xmlns_compression_protocol = "http://jabber.org/protocol/compress" +local xmlns_stream = "http://etherx.jabber.org/streams"; +local compression_stream_feature = st.stanza("compression", {xmlns=xmlns_compression_feature}):tag("method"):text("zlib"):up(); +local add_filter = require "util.filters".add_filter; + +local compression_level = module:get_option_number("compression_level", 7); + +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:hook("stream-features", function(event) + local origin, features = event.origin, event.features; + if not origin.compressed and (origin.type == "c2s" or origin.type == "s2sin" or origin.type == "s2sout") then + -- FIXME only advertise compression support when TLS layer has no compression enabled + features:add_child(compression_stream_feature); + end +end); + +module:hook("s2s-stream-features", function(event) + local origin, features = event.origin, event.features; + -- FIXME only advertise compression support when TLS layer has no compression enabled + if not origin.compressed and (origin.type == "c2s" or origin.type == "s2sin" or origin.type == "s2sout") then + features:add_child(compression_stream_feature); + end +end); + +-- Hook to activate compression if remote server supports it. +module:hook_stanza(xmlns_stream, "features", + function (session, stanza) + if not session.compressed and (session.type == "c2s" or session.type == "s2sin" or session.type == "s2sout") then + -- does remote server support compression? + local comp_st = stanza:child_with_name("compression"); + if comp_st then + -- do we support the mechanism + for a in comp_st:children() do + local algorithm = a[1] + if algorithm == "zlib" then + session.sends2s(st.stanza("compress", {xmlns=xmlns_compression_protocol}):tag("method"):text("zlib")) + session.log("debug", "Enabled compression using zlib.") + return true; + end + end + session.log("debug", "Remote server supports no compression algorithm we support.") + end + end + end +, 250); + + +-- returns either nil or a fully functional ready to use inflate stream +local function get_deflate_stream(session) + 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.sends2s or session.send)(error_st); + session.log("error", "Failed to create zlib.deflate filter."); + module:log("error", "%s", tostring(deflate_stream)); + return + end + return deflate_stream +end + +-- returns either nil or a fully functional ready to use inflate stream +local function get_inflate_stream(session) + 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.sends2s or session.send)(error_st); + session.log("error", "Failed to create zlib.inflate filter."); + module:log("error", "%s", tostring(inflate_stream)); + return + end + return inflate_stream +end + +-- setup compression for a stream +local function setup_compression(session, deflate_stream) + add_filter(session, "bytes/out", function(t) + local status, compressed, eof = pcall(deflate_stream, tostring(t), 'sync'); + if status == false then + module:log("warn", "%s", tostring(compressed)); + session:close({ + condition = "undefined-condition"; + text = compressed; + extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed"); + }); + return; + end + return compressed; + end); +end + +-- setup decompression for a stream +local function setup_decompression(session, inflate_stream) + add_filter(session, "bytes/in", function(data) + local status, decompressed, eof = pcall(inflate_stream, data); + if status == false then + module:log("warn", "%s", tostring(decompressed)); + session:close({ + condition = "undefined-condition"; + text = decompressed; + extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed"); + }); + return; + end + return decompressed; + end); +end + +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(); + session:open_stream(session.from_host, session.to_host); + 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."); + + -- 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 + + (session.sends2s or session.send)(st.stanza("compressed", {xmlns=xmlns_compression_protocol})); + session:reset_stream(); + + -- setup compression for session.w + setup_compression(session, deflate_stream); + + -- setup decompression for session.data + setup_decompression(session, inflate_stream); + + session.compressed = true; + elseif method then + session.log("debug", "%s compression selected, but we don't support it.", tostring(method)); + local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method"); + (session.sends2s or session.send)(error_st); + else + (session.sends2s or session.send)(st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed")); + end + return true; + end +end); + |