libs/http/luasrc/http/protocol/filter.lua

   1 --[[
   2
   3 HTTP protocol implementation for LuCI - filter implementation
   4 (c) 2008 Freifunk Leipzig / Jo-Philipp Wich <xm@leipzig.freifunk.net>
   5
   6 Licensed under the Apache License, Version 2.0 (the "License");
   7 you may not use this file except in compliance with the License.
   8 You may obtain a copy of the License at
   9
  10         http://www.apache.org/licenses/LICENSE-2.0
  11
  12 $Id$
  13
  14 ]]--
  15
  16 module("luci.http.protocol.filter", package.seeall)
  17
  18 local ltn12 = require("luci.ltn12")
  19
  20
  21 -- Factory that produces a filter which normalizes chunked transfer encoding
  22 function decode_chunked()
  23
  24         local length = 0
  25         local read   = 0
  26
  27         return ltn12.filter.cycle(
  28                 function( chunk, ctx )
  29
  30                         if chunk ~= nil then
  31
  32                                 -- EOF
  33                                 if ctx == nil then
  34                                         if ( length - read ) > 0 then
  35                                                 return nil, "Unexpected EOF"
  36                                         else
  37                                                 return ""
  38                                         end
  39                                 end
  40
  41                                 chunk = ctx .. chunk
  42
  43                                 local buf = ""
  44                                 while true do
  45
  46                                         if read == length then
  47
  48                                                 -- Find chunk length indicator
  49                                                 local spos, epos = chunk:find("^\r?\n?[a-fA-F0-9]+ *\r\n")
  50                                                 if spos and spos == 1 then
  51                                                         read   = 0
  52                                                         length = tonumber(
  53                                                                 chunk:sub( 1, epos ):gsub( "[^a-fA-F0-9]", "" ), 16
  54                                                         )
  55
  56                                                         -- Check for end of chunk
  57                                                         if length > 0 then
  58                                                                 chunk = chunk:sub( epos + 1, #chunk )
  59                                                         else
  60                                                                 return buf, ""
  61                                                         end
  62                                                 else
  63                                                         return "", nil
  64                                                 end
  65                                         else
  66                                                 if ( read + #chunk ) <= length then
  67                                                         read = read + #chunk
  68                                                         return buf .. chunk, ""
  69                                                 else
  70                                                         local rest = length - read
  71                                                         read  = read + rest
  72                                                         buf   = buf .. chunk:sub( 1, rest )
  73                                                         chunk = chunk:sub( rest + 1, #chunk )
  74                                                 end
  75                                         end
  76                                 end
  77                         end
  78                 end,
  79                 ""
  80         )
  81 end