-- Copyright 2008 Freifunk Leipzig / Jo-Philipp Wich -- Licensed to the public under the Apache License 2.0. -- This class contains several functions useful for http message- and content -- decoding and to retrive form data from raw http messages. module("luci.http.protocol", package.seeall) local ltn12 = require("luci.ltn12") HTTP_MAX_CONTENT = 1024*8 -- 8 kB maximum content size -- the "+" sign to " " - and return the decoded string. function urldecode( str, no_plus ) local function __chrdec( hex ) return string.char( tonumber( hex, 16 ) ) end if type(str) == "string" then if not no_plus then str = str:gsub( "+", " " ) end str = str:gsub( "%%([a-fA-F0-9][a-fA-F0-9])", __chrdec ) end return str end -- from given url or string. Returns a table with urldecoded values. -- Simple parameters are stored as string values associated with the parameter -- name within the table. Parameters with multiple values are stored as array -- containing the corresponding values. function urldecode_params( url, tbl ) local params = tbl or { } if url:find("?") then url = url:gsub( "^.+%?([^?]+)", "%1" ) end for pair in url:gmatch( "[^&;]+" ) do -- find key and value local key = urldecode( pair:match("^([^=]+)") ) local val = urldecode( pair:match("^[^=]+=(.+)$") ) -- store if type(key) == "string" and key:len() > 0 then if type(val) ~= "string" then val = "" end if not params[key] then params[key] = val elseif type(params[key]) ~= "table" then params[key] = { params[key], val } else table.insert( params[key], val ) end end end return params end function urlencode( str ) local function __chrenc( chr ) return string.format( "%%%02x", string.byte( chr ) ) end if type(str) == "string" then str = str:gsub( "([^a-zA-Z0-9$_%-%.%~])", __chrenc ) end return str end -- separated by "&". Tables are encoded as parameters with multiple values by -- repeating the parameter name with each value. function urlencode_params( tbl ) local enc = "" for k, v in pairs(tbl) do if type(v) == "table" then for i, v2 in ipairs(v) do enc = enc .. ( #enc > 0 and "&" or "" ) .. urlencode(k) .. "=" .. urlencode(v2) end else enc = enc .. ( #enc > 0 and "&" or "" ) .. urlencode(k) .. "=" .. urlencode(v) end end return enc end -- (Internal function) -- Initialize given parameter and coerce string into table when the parameter -- already exists. local function __initval( tbl, key ) if tbl[key] == nil then tbl[key] = "" elseif type(tbl[key]) == "string" then tbl[key] = { tbl[key], "" } else table.insert( tbl[key], "" ) end end -- (Internal function) -- Append given data to given parameter, either by extending the string value -- or by appending it to the last string in the parameter's value table. local function __appendval( tbl, key, chunk ) if type(tbl[key]) == "table" then tbl[key][#tbl[key]] = tbl[key][#tbl[key]] .. chunk else tbl[key] = tbl[key] .. chunk end end -- (Internal function) -- Finish the value of given parameter, either by transforming the string value -- or - in the case of multi value parameters - the last element in the -- associated values table. local function __finishval( tbl, key, handler ) if handler then if type(tbl[key]) == "table" then tbl[key][#tbl[key]] = handler( tbl[key][#tbl[key]] ) else tbl[key] = handler( tbl[key] ) end end end -- Table of our process states local process_states = { } -- Extract "magic", the first line of a http message. -- Extracts the message type ("get", "post" or "response"), the requested uri -- or the status code if the line descripes a http response. process_states['magic'] = function( msg, chunk, err ) if chunk ~= nil then -- ignore empty lines before request if #chunk == 0 then return true, nil end -- Is it a request? local method, uri, http_ver = chunk:match("^([A-Z]+) ([^ ]+) HTTP/([01]%.[019])$") -- Yup, it is if method then msg.type = "request" msg.request_method = method:lower() msg.request_uri = uri msg.http_version = tonumber( http_ver ) msg.headers = { } -- We're done, next state is header parsing return true, function( chunk ) return process_states['headers']( msg, chunk ) end -- Is it a response? else local http_ver, code, message = chunk:match("^HTTP/([01]%.[019]) ([0-9]+) ([^\r\n]+)$") -- Is a response if code then msg.type = "response" msg.status_code = code msg.status_message = message msg.http_version = tonumber( http_ver ) msg.headers = { } -- We're done, next state is header parsing return true, function( chunk ) return process_states['headers']( msg, chunk ) end end end end -- Can't handle it return nil, "Invalid HTTP message magic" end -- Extract headers from given string. process_states['headers'] = function( msg, chunk ) if chunk ~= nil then -- Look for a valid header format local hdr, val = chunk:match( "^([A-Za-z][A-Za-z0-9%-_]+): +(.+)$" ) if type(hdr) == "string" and hdr:len() > 0 and type(val) == "string" and val:len() > 0 then msg.headers[hdr] = val -- Valid header line, proceed return true, nil elseif #chunk == 0 then -- Empty line, we won't accept data anymore return false, nil else -- Junk data return nil, "Invalid HTTP header received" end else return nil, "Unexpected EOF" end end -- data line by line with the trailing \r\n stripped of. function header_source( sock ) return ltn12.source.simplify( function() local chunk, err, part = sock:receive("*l") -- Line too long if chunk == nil then if err ~= "timeout" then return nil, part and "Line exceeds maximum allowed length" or "Unexpected EOF" else return nil, err end -- Line ok elseif chunk ~= nil then -- Strip trailing CR chunk = chunk:gsub("\r$","") return chunk, nil end end ) end -- Content-Type. Stores all extracted data associated with its parameter name -- in the params table withing the given message object. Multiple parameter -- values are stored as tables, ordinary ones as strings. -- If an optional file callback function is given then it is feeded with the -- file contents chunk by chunk and only the extracted file name is stored -- within the params table. The callback function will be called subsequently -- with three arguments: -- o Table containing decoded (name, file) and raw (headers) mime header data -- o String value containing a chunk of the file data -- o Boolean which indicates wheather the current chunk is the last one (eof) function mimedecode_message_body( src, msg, filecb ) if msg and msg.env.CONTENT_TYPE then msg.mime_boundary = msg.env.CONTENT_TYPE:match("^multipart/form%-data; boundary=(.+)$") end if not msg.mime_boundary then return nil, "Invalid Content-Type found" end local tlen = 0 local inhdr = false local field = nil local store = nil local lchunk = nil local function parse_headers( chunk, field ) local stat repeat chunk, stat = chunk:gsub( "^([A-Z][A-Za-z0-9%-_]+): +([^\r\n]+)\r\n", function(k,v) field.headers[k] = v return "" end ) until stat == 0 chunk, stat = chunk:gsub("^\r\n","") -- End of headers if stat > 0 then if field.headers["Content-Disposition"] then if field.headers["Content-Disposition"]:match("^form%-data; ") then field.name = field.headers["Content-Disposition"]:match('name="(.-)"') field.file = field.headers["Content-Disposition"]:match('filename="(.+)"$') end end if not field.headers["Content-Type"] then field.headers["Content-Type"] = "text/plain" end if field.name and field.file and filecb then __initval( msg.params, field.name ) __appendval( msg.params, field.name, field.file ) store = filecb elseif field.name then __initval( msg.params, field.name ) store = function( hdr, buf, eof ) __appendval( msg.params, field.name, buf ) end else store = nil end return chunk, true end return chunk, false end local function snk( chunk ) tlen = tlen + ( chunk and #chunk or 0 ) if msg.env.CONTENT_LENGTH and tlen > tonumber(msg.env.CONTENT_LENGTH) + 2 then return nil, "Message body size exceeds Content-Length" end if chunk and not lchunk then lchunk = "\r\n" .. chunk elseif lchunk then local data = lchunk .. ( chunk or "" ) local spos, epos, found repeat spos, epos = data:find( "\r\n--" .. msg.mime_boundary .. "\r\n", 1, true ) if not spos then spos, epos = data:find( "\r\n--" .. msg.mime_boundary .. "--\r\n", 1, true ) end if spos then local predata = data:sub( 1, spos - 1 ) if inhdr then predata, eof = parse_headers( predata, field ) if not eof then return nil, "Invalid MIME section header" elseif not field.name then return nil, "Invalid Content-Disposition header" end end if store then store( field, predata, true ) end field = { headers = { } } found = found or true data, eof = parse_headers( data:sub( epos + 1, #data ), field ) inhdr = not eof end until not spos if found then -- We found at least some boundary. Save -- the unparsed remaining data for the -- next chunk. lchunk, data = data, nil else -- There was a complete chunk without a boundary. Parse it as headers or -- append it as data, depending on our current state. if inhdr then lchunk, eof = parse_headers( data, field ) inhdr = not eof else -- We're inside data, so append the data. Note that we only append -- lchunk, not all of data, since there is a chance that chunk -- contains half a boundary. Assuming that each chunk is at least the -- boundary in size, this should prevent problems store( field, lchunk, false ) lchunk, chunk = chunk, nil end end end return true end return ltn12.pump.all( src, snk ) end -- Content-Type. Stores all extracted data associated with its parameter name -- in the params table withing the given message object. Multiple parameter -- values are stored as tables, ordinary ones as strings. function urldecode_message_body( src, msg ) local tlen = 0 local lchunk = nil local function snk( chunk ) tlen = tlen + ( chunk and #chunk or 0 ) if msg.env.CONTENT_LENGTH and tlen > tonumber(msg.env.CONTENT_LENGTH) + 2 then return nil, "Message body size exceeds Content-Length" elseif tlen > HTTP_MAX_CONTENT then return nil, "Message body size exceeds maximum allowed length" end if not lchunk and chunk then lchunk = chunk elseif lchunk then local data = lchunk .. ( chunk or "&" ) local spos, epos repeat spos, epos = data:find("^.-[;&]") if spos then local pair = data:sub( spos, epos - 1 ) local key = pair:match("^(.-)=") local val = pair:match("=([^%s]*)%s*$") if key and #key > 0 then __initval( msg.params, key ) __appendval( msg.params, key, val ) __finishval( msg.params, key, urldecode ) end data = data:sub( epos + 1, #data ) end until not spos lchunk = data end return true end return ltn12.pump.all( src, snk ) end -- version, message headers and resulting CGI environment variables from the -- given ltn12 source. function parse_message_header( src ) local ok = true local msg = { } local sink = ltn12.sink.simplify( function( chunk ) return process_states['magic']( msg, chunk ) end ) -- Pump input data... while ok do -- get data ok, err = ltn12.pump.step( src, sink ) -- error if not ok and err then return nil, err -- eof elseif not ok then -- Process get parameters if ( msg.request_method == "get" or msg.request_method == "post" ) and msg.request_uri:match("?") then msg.params = urldecode_params( msg.request_uri ) else msg.params = { } end -- Populate common environment variables msg.env = { CONTENT_LENGTH = msg.headers['Content-Length']; CONTENT_TYPE = msg.headers['Content-Type'] or msg.headers['Content-type']; REQUEST_METHOD = msg.request_method:upper(); REQUEST_URI = msg.request_uri; SCRIPT_NAME = msg.request_uri:gsub("?.+$",""); SCRIPT_FILENAME = ""; -- XXX implement me SERVER_PROTOCOL = "HTTP/" .. string.format("%.1f", msg.http_version); QUERY_STRING = msg.request_uri:match("?") and msg.request_uri:gsub("^.+?","") or "" } -- Populate HTTP_* environment variables for i, hdr in ipairs( { 'Accept', 'Accept-Charset', 'Accept-Encoding', 'Accept-Language', 'Connection', 'Cookie', 'Host', 'Referer', 'User-Agent', } ) do local var = 'HTTP_' .. hdr:upper():gsub("%-","_") local val = msg.headers[hdr] msg.env[var] = val end end end return msg end -- This function will examine the Content-Type within the given message object -- to select the appropriate content decoder. -- Currently the application/x-www-urlencoded and application/form-data -- mime types are supported. If the encountered content encoding can't be -- handled then the whole message body will be stored unaltered as "content" -- property within the given message object. function parse_message_body( src, msg, filecb ) -- Is it multipart/mime ? if msg.env.REQUEST_METHOD == "POST" and msg.env.CONTENT_TYPE and msg.env.CONTENT_TYPE:match("^multipart/form%-data") then return mimedecode_message_body( src, msg, filecb ) -- Is it application/x-www-form-urlencoded ? elseif msg.env.REQUEST_METHOD == "POST" and msg.env.CONTENT_TYPE and msg.env.CONTENT_TYPE:match("^application/x%-www%-form%-urlencoded") then return urldecode_message_body( src, msg, filecb ) -- Unhandled encoding -- If a file callback is given then feed it chunk by chunk, else -- store whole buffer in message.content else local sink -- If we have a file callback then feed it if type(filecb) == "function" then local meta = { name = "raw", encoding = msg.env.CONTENT_TYPE } sink = function( chunk ) if chunk then return filecb(meta, chunk, false) else return filecb(meta, nil, true) end end -- ... else append to .content else msg.content = "" msg.content_length = 0 sink = function( chunk ) if chunk then if ( msg.content_length + #chunk ) <= HTTP_MAX_CONTENT then msg.content = msg.content .. chunk msg.content_length = msg.content_length + #chunk return true else return nil, "POST data exceeds maximum allowed length" end end return true end end -- Pump data... while true do local ok, err = ltn12.pump.step( src, sink ) if not ok and err then return nil, err elseif not ok then -- eof return true end end return true end end statusmsg = { [200] = "OK", [206] = "Partial Content", [301] = "Moved Permanently", [302] = "Found", [304] = "Not Modified", [400] = "Bad Request", [403] = "Forbidden", [404] = "Not Found", [405] = "Method Not Allowed", [408] = "Request Time-out", [411] = "Length Required", [412] = "Precondition Failed", [416] = "Requested range not satisfiable", [500] = "Internal Server Error", [503] = "Server Unavailable", }