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1 -- Prosody IM |
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2 -- Copyright (C) 2009-2012 Tobias Markmann |
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3 -- |
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4 -- This project is MIT/X11 licensed. Please see the |
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5 -- COPYING file in the source package for more information. |
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6 -- |
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7 |
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8 local st = require "util.stanza"; |
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9 local zlib = require "zlib"; |
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10 local pcall = pcall; |
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11 local tostring = tostring; |
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12 |
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13 local xmlns_compression_feature = "http://jabber.org/features/compress" |
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14 local xmlns_compression_protocol = "http://jabber.org/protocol/compress" |
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15 local xmlns_stream = "http://etherx.jabber.org/streams"; |
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16 local compression_stream_feature = st.stanza("compression", {xmlns=xmlns_compression_feature}):tag("method"):text("zlib"):up(); |
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17 local add_filter = require "util.filters".add_filter; |
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18 |
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19 local compression_level = module:get_option_number("compression_level", 7); |
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20 |
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21 if not compression_level or compression_level < 1 or compression_level > 9 then |
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22 module:log("warn", "Invalid compression level in config: %s", tostring(compression_level)); |
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23 module:log("warn", "Module loading aborted. Compression won't be available."); |
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24 return; |
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25 end |
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26 |
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27 module:hook("stream-features", function(event) |
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28 local origin, features = event.origin, event.features; |
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29 if not origin.compressed and origin.type == "c2s" then |
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30 features:add_child(compression_stream_feature); |
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31 end |
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32 end); |
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33 |
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34 module:hook("s2s-stream-features", function(event) |
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35 local origin, features = event.origin, event.features; |
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36 if not origin.compressed and origin.type == "s2sin" then |
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37 features:add_child(compression_stream_feature); |
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38 end |
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39 end); |
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40 |
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41 -- Hook to activate compression if remote server supports it. |
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42 module:hook_stanza(xmlns_stream, "features", |
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43 function (session, stanza) |
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44 if not session.compressed and session.type == "s2sout" then |
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45 -- does remote server support compression? |
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46 local comp_st = stanza:get_child("compression", xmlns_compression_feature); |
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47 if comp_st then |
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48 -- do we support the mechanism |
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49 for a in comp_st:childtags("method") do |
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50 local algorithm = a:get_text(); |
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51 if algorithm == "zlib" then |
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52 session.sends2s(st.stanza("compress", {xmlns=xmlns_compression_protocol}):tag("method"):text("zlib")) |
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53 session.log("debug", "Enabled compression using zlib.") |
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54 return true; |
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55 end |
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56 end |
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57 session.log("debug", "Remote server supports no compression algorithm we support.") |
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58 end |
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59 end |
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60 end |
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61 , 250); |
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62 |
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63 |
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64 -- returns either nil or a fully functional ready to use inflate stream |
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65 local function get_deflate_stream(session) |
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66 local status, deflate_stream = pcall(zlib.deflate, compression_level); |
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67 if status == false then |
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68 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); |
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69 (session.sends2s or session.send)(error_st); |
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70 session.log("error", "Failed to create zlib.deflate filter."); |
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71 module:log("error", "%s", tostring(deflate_stream)); |
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72 return |
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73 end |
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74 return deflate_stream |
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75 end |
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76 |
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77 -- returns either nil or a fully functional ready to use inflate stream |
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78 local function get_inflate_stream(session) |
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79 local status, inflate_stream = pcall(zlib.inflate); |
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80 if status == false then |
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81 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); |
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82 (session.sends2s or session.send)(error_st); |
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83 session.log("error", "Failed to create zlib.inflate filter."); |
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84 module:log("error", "%s", tostring(inflate_stream)); |
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85 return |
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86 end |
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87 return inflate_stream |
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88 end |
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89 |
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90 -- setup compression for a stream |
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91 local function setup_compression(session, deflate_stream) |
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92 add_filter(session, "bytes/out", function(t) |
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93 local status, compressed, eof = pcall(deflate_stream, tostring(t), 'sync'); |
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94 if status == false then |
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95 module:log("warn", "%s", tostring(compressed)); |
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96 session:close({ |
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97 condition = "undefined-condition"; |
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98 text = compressed; |
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99 extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed"); |
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100 }); |
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101 return; |
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102 end |
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103 return compressed; |
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104 end); |
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105 end |
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106 |
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107 -- setup decompression for a stream |
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108 local function setup_decompression(session, inflate_stream) |
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109 add_filter(session, "bytes/in", function(data) |
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110 local status, decompressed, eof = pcall(inflate_stream, data); |
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111 if status == false then |
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112 module:log("warn", "%s", tostring(decompressed)); |
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113 session:close({ |
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114 condition = "undefined-condition"; |
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115 text = decompressed; |
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116 extra = st.stanza("failure", {xmlns="http://jabber.org/protocol/compress"}):tag("processing-failed"); |
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117 }); |
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118 return; |
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119 end |
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120 return decompressed; |
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121 end); |
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122 end |
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123 |
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124 module:hook("stanza/http://jabber.org/protocol/compress:compressed", function(event) |
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125 local session = event.origin; |
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126 |
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127 if session.type == "s2sout" then |
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128 session.log("debug", "Activating compression...") |
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129 -- create deflate and inflate streams |
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130 local deflate_stream = get_deflate_stream(session); |
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131 if not deflate_stream then return true; end |
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132 |
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133 local inflate_stream = get_inflate_stream(session); |
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134 if not inflate_stream then return true; end |
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135 |
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136 -- setup compression for session.w |
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137 setup_compression(session, deflate_stream); |
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138 |
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139 -- setup decompression for session.data |
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140 setup_decompression(session, inflate_stream); |
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141 session:reset_stream(); |
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142 session:open_stream(session.from_host, session.to_host); |
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143 session.compressed = true; |
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144 return true; |
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145 end |
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146 end); |
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147 |
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148 module:hook("stanza/http://jabber.org/protocol/compress:failure", function(event) |
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149 local err = event.stanza:get_child(); |
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150 (event.origin.log or module._log)("warn", "Compression setup failed (%s)", err and err.name or "unknown reason"); |
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151 return true; |
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152 end); |
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153 |
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154 module:hook("stanza/http://jabber.org/protocol/compress:compress", function(event) |
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155 local session, stanza = event.origin, event.stanza; |
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156 |
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157 if session.type == "c2s" or session.type == "s2sin" then |
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158 -- fail if we are already compressed |
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159 if session.compressed then |
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160 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed"); |
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161 (session.sends2s or session.send)(error_st); |
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162 session.log("debug", "Client tried to establish another compression layer."); |
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163 return true; |
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164 end |
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165 |
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166 -- checking if the compression method is supported |
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167 local method = stanza:get_child_text("method"); |
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168 if method == "zlib" then |
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169 session.log("debug", "zlib compression enabled."); |
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170 |
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171 -- create deflate and inflate streams |
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172 local deflate_stream = get_deflate_stream(session); |
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173 if not deflate_stream then return true; end |
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174 |
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175 local inflate_stream = get_inflate_stream(session); |
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176 if not inflate_stream then return true; end |
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177 |
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178 (session.sends2s or session.send)(st.stanza("compressed", {xmlns=xmlns_compression_protocol})); |
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179 session:reset_stream(); |
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180 |
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181 -- setup compression for session.w |
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182 setup_compression(session, deflate_stream); |
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183 |
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184 -- setup decompression for session.data |
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185 setup_decompression(session, inflate_stream); |
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186 |
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187 session.compressed = true; |
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188 elseif method then |
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189 session.log("debug", "%s compression selected, but we don't support it.", tostring(method)); |
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190 local error_st = st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("unsupported-method"); |
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191 (session.sends2s or session.send)(error_st); |
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192 else |
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193 (session.sends2s or session.send)(st.stanza("failure", {xmlns=xmlns_compression_protocol}):tag("setup-failed")); |
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194 end |
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195 return true; |
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196 end |
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197 end); |
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198 |