1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
-- 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 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;
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("info", "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)
session.log(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", "%s", tostring(compressed));
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
session:close({
condition = "undefined-condition";
text = decompressed;
extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed");
});
module:log("warn", "%s", tostring(decompressed));
return;
end
return decompressed;
end);
end
module:add_handler({"s2sout_unauthed", "s2sout"}, "compressed", xmlns_compression_protocol,
function(session ,stanza)
session.log("debug", "Activating compression...")
-- create deflate and inflate streams
local deflate_stream = get_deflate_stream(session);
if not deflate_stream then return end
local inflate_stream = get_inflate_stream(session);
if not inflate_stream then return end
-- setup compression for session.w
setup_compression(session, deflate_stream);
-- setup decompression for session.data
setup_decompression(session, inflate_stream);
local session_reset_stream = session.reset_stream;
session.reset_stream = function(session)
session_reset_stream(session);
setup_decompression(session, inflate_stream);
return true;
end;
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;
end
);
module:add_handler({"c2s_unauthed", "c2s", "s2sin_unauthed", "s2sin"}, "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("setup-failed");
(session.sends2s or session.send)(error_st);
session.log("debug", "Client tried to establish another compression layer.");
return;
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 end
local inflate_stream = get_inflate_stream(session);
if not inflate_stream then return 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);
local session_reset_stream = session.reset_stream;
session.reset_stream = function(session)
session_reset_stream(session);
setup_decompression(session, inflate_stream);
return true;
end;
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
end
);
|
