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Diffstat (limited to 'modules/luci-base/luasrc/http/protocol.lua')
| -rw-r--r-- | modules/luci-base/luasrc/http/protocol.lua | 688 |
1 files changed, 688 insertions, 0 deletions
diff --git a/modules/luci-base/luasrc/http/protocol.lua b/modules/luci-base/luasrc/http/protocol.lua new file mode 100644 index 0000000000..6431b04031 --- /dev/null +++ b/modules/luci-base/luasrc/http/protocol.lua @@ -0,0 +1,688 @@ +--[[ + +HTTP protocol implementation for LuCI +(c) 2008 Freifunk Leipzig / Jo-Philipp Wich <xm@leipzig.freifunk.net> + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +$Id$ + +]]-- + +--- LuCI http protocol class. +-- 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 + +--- Decode an urlencoded string - optionally without decoding +-- the "+" sign to " " - and return the decoded string. +-- @param str Input string in x-www-urlencoded format +-- @param no_plus Don't decode "+" signs to spaces +-- @return The decoded string +-- @see urlencode +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 + +--- Extract and split urlencoded data pairs, separated bei either "&" or ";" +-- 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. +-- @param url The url or string which contains x-www-urlencoded form data +-- @param tbl Use the given table for storing values (optional) +-- @return Table containing the urldecoded parameters +-- @see urlencode_params +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("^[^=]+=(.+)$") ) + + -- store + if type(key) == "string" and key:len() > 0 then + if type(val) ~= "string" then val = "" end + + if not params[key] then + params[key] = val + elseif type(params[key]) ~= "table" then + params[key] = { params[key], val } + else + table.insert( params[key], val ) + end + end + end + + return params +end + +--- Encode given string to x-www-urlencoded format. +-- @param str String to encode +-- @return String containing the encoded data +-- @see urldecode +function urlencode( str ) + + local function __chrenc( chr ) + return string.format( + "%%%02x", string.byte( chr ) + ) + end + + if type(str) == "string" then + str = str:gsub( + "([^a-zA-Z0-9$_%-%.%+!*'(),])", + __chrenc + ) + end + + return str +end + +--- Encode each key-value-pair in given table to x-www-urlencoded format, +-- separated by "&". Tables are encoded as parameters with multiple values by +-- repeating the parameter name with each value. +-- @param tbl Table with the values +-- @return String containing encoded values +-- @see urldecode_params +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. +-- @param tbl Table where parameter should be created +-- @param key Parameter name +-- @return Always nil +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. +-- @param tbl Table containing the previously initialized parameter value +-- @param key Parameter name +-- @param chunk String containing the data to append +-- @return Always nil +-- @see __initval +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. +-- @param tbl Table containing the previously initialized parameter value +-- @param key Parameter name +-- @param handler Function which transforms the parameter value +-- @return Always nil +-- @see __initval +-- @see __appendval +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%-_]+): +(.+)$" ) + + if type(hdr) == "string" and hdr:len() > 0 and + type(val) == "string" and val:len() > 0 + then + msg.headers[hdr] = val + + -- Valid header line, proceed + return true, nil + + elseif #chunk == 0 then + -- Empty line, we won't accept data anymore + return false, nil + else + -- Junk data + return nil, "Invalid HTTP header received" + end + else + return nil, "Unexpected EOF" + end +end + + +--- Creates a ltn12 source from the given socket. The source will return it's +-- data line by line with the trailing \r\n stripped of. +-- @param sock Readable network socket +-- @return Ltn12 source function +function header_source( sock ) + return ltn12.source.simplify( function() + + local chunk, err, part = sock:receive("*l") + + -- Line too long + if chunk == nil then + if err ~= "timeout" then + return nil, part + and "Line exceeds maximum allowed length" + or "Unexpected EOF" + else + return nil, err + end + + -- Line ok + elseif chunk ~= nil then + + -- Strip trailing CR + chunk = chunk:gsub("\r$","") + + return chunk, nil + end + end ) +end + +--- Decode a mime encoded http message body with multipart/form-data +-- 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) +-- @param src Ltn12 source function +-- @param msg HTTP message object +-- @param filecb File callback function (optional) +-- @return Value indicating successful operation (not nil means "ok") +-- @return String containing the error if unsuccessful +-- @see parse_message_header +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 + +--- Decode an urlencoded http message body with application/x-www-urlencoded +-- 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. +-- @param src Ltn12 source function +-- @param msg HTTP message object +-- @return Value indicating successful operation (not nil means "ok") +-- @return String containing the error if unsuccessful +-- @see parse_message_header +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*$") + + if key and #key > 0 then + __initval( msg.params, key ) + __appendval( msg.params, key, val ) + __finishval( msg.params, key, urldecode ) + end + + data = data:sub( epos + 1, #data ) + end + until not spos + + lchunk = data + end + + return true + end + + return ltn12.pump.all( src, snk ) +end + +--- Try to extract an http message header including information like protocol +-- version, message headers and resulting CGI environment variables from the +-- given ltn12 source. +-- @param src Ltn12 source function +-- @return HTTP message object +-- @see parse_message_body +function parse_message_header( src ) + + local ok = true + local msg = { } + + local sink = ltn12.sink.simplify( + function( chunk ) + return process_states['magic']( msg, chunk ) + end + ) + + -- Pump input data... + while ok do + + -- get data + ok, err = ltn12.pump.step( src, sink ) + + -- error + if not ok and err then + return nil, err + + -- eof + elseif not ok then + + -- Process get parameters + if ( msg.request_method == "get" or msg.request_method == "post" ) and + msg.request_uri:match("?") + then + msg.params = urldecode_params( msg.request_uri ) + else + msg.params = { } + end + + -- Populate common environment variables + msg.env = { + CONTENT_LENGTH = msg.headers['Content-Length']; + CONTENT_TYPE = msg.headers['Content-Type'] or msg.headers['Content-type']; + REQUEST_METHOD = msg.request_method:upper(); + REQUEST_URI = msg.request_uri; + SCRIPT_NAME = msg.request_uri:gsub("?.+$",""); + 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 + +--- Try to extract and decode a http message body from the given ltn12 source. +-- 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. +-- @param src Ltn12 source function +-- @param msg HTTP message object +-- @param filecb File data callback (optional, see mimedecode_message_body()) +-- @return Value indicating successful operation (not nil means "ok") +-- @return String containing the error if unsuccessful +-- @see parse_message_header +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 + sink = filecb + + -- ... else append to .content + else + msg.content = "" + msg.content_length = 0 + + sink = function( chunk, err ) + 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 + +--- Table containing human readable messages for several http status codes. +-- @class table +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", +} |