mod_admin_telnet: Don't rely on getpeerchain returning an empty list
[prosody.git] / plugins / mod_compression.lua
index f1cae7378e23019ae8b6063eb4a8aa9a6582cda7..928560993bcd367d61cdd45c106a69365b08235e 100644 (file)
@@ -1,5 +1,5 @@
 -- Prosody IM
--- Copyright (C) 2009 Tobias Markmann
+-- 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("compression_level");
+local compression_level = module:get_option_number("compression_level", 7);
 
--- 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);
+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
-);
-
--- 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
+, 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);
                        
-                       -- 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);
+               -- 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);
                                
-                               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
+                       -- 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);
+