local st = require "util.stanza";
local zlib = require "zlib";
-local print = print
+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 features:add_child(compression_stream_feature); end
+ 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
);
-module:add_handler("c2s_unauthed", "compress", xmlns_compression_protocol,
+-- 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:reset_stream();
-- create deflate and inflate streams
- local deflate_stream = zlib.deflate(9);
- local inflate_stream = zlib.inflate();
+ 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 compressed, eof = deflate_stream(tostring(t), 'sync');
+ 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;
local function setup_decompression(session)
local old_data = session.data
session.data = function(conn, data)
- local decompressed, eof = inflate_stream(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