X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=plugins%2Fmod_compression.lua;h=82403016d9e936c47503a18e21ca863f5dede10d;hb=7cba78348a3ff1197f0a790a7cc3068151296483;hp=4b8988339263c279089340b783fb292709007b1b;hpb=05077bbf1b78f9275502295640b5274cd313e102;p=prosody.git

diff --git a/plugins/mod_compression.lua b/plugins/mod_compression.lua
index 4b898833..82403016 100644
--- a/plugins/mod_compression.lua
+++ b/plugins/mod_compression.lua
@@ -6,30 +6,197 @@
 --
 
 local st = require "util.stanza";
-local print = print
+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");
+-- if not defined assume admin wants best compression
+if compression_level == nil then compression_level = 9 end;
 
-module:add_event_hook("stream-features", 
-		function (session, features)
-			features:add_child(compression_stream_feature);
-		end
-);
-
-module:add_handler("c2s_unauthed", "compress", xmlns_compression_protocol, 
-		function(session, stanza)
-			-- 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}));
-			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);
+
+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:hook("stream-features", function(event)
+	local origin, features = event.origin, event.features;
+	if not origin.compressed 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 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 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();
+		local default_stream_attr = {xmlns = "jabber:server", ["xmlns:stream"] = "http://etherx.jabber.org/streams",
+									["xmlns:db"] = 'jabber:server:dialback', version = "1.0", to = session.to_host, from = session.from_host};
+		session.sends2s("<?xml version='1.0'?>");
+		session.sends2s(st.stanza("stream:stream", default_stream_attr):top_tag());
+		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);
+