lib/nitcorn/http_request.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2013 Frederic Sevillano
   4 # Copyright 2013 Jean-Philippe Caissy <jpcaissy@piji.ca>
   5 # Copyright 2014 Alexis Laferrière <alexis.laf@xymus.net>
   6 #
   7 # Licensed under the Apache License, Version 2.0 (the "License");
   8 # you may not use this file except in compliance with the License.
   9 # You may obtain a copy of the License at
  10 #
  11 #     http://www.apache.org/licenses/LICENSE-2.0
  12 #
  13 # Unless required by applicable law or agreed to in writing, software
  14 # distributed under the License is distributed on an "AS IS" BASIS,
  15 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16 # See the License for the specific language governing permissions and
  17 # limitations under the License.
  18
  19 # Provides the `HttpRequest` class and services to create it
  20 module http_request
  21
  22 import standard
  23
  24 # A request received over HTTP, is build by `HttpRequestParser`
  25 class HttpRequest
  26         private init do end
  27
  28         # HTTP protocol version
  29         var http_version: String
  30
  31         # Method of this request (GET or POST)
  32         var method: String
  33
  34         # The host targetter by this request (usually the server)
  35         var host: String
  36
  37         # The full URL requested by the client (including the `query_string`)
  38         var url: String
  39
  40         # The resource requested by the client (only the page, not the `query_string`)
  41         var uri: String
  42
  43         # The string following `?` in the requested URL
  44         var query_string = ""
  45
  46         # The header of this request
  47         var header = new HashMap[String, String]
  48
  49         # The content of the cookie of this request
  50         var cookie = new HashMap[String, String]
  51
  52         # The arguments passed with the GET method,
  53         var get_args = new HashMap[String, String]
  54
  55         # The arguments passed with the POST method
  56         var post_args = new HashMap[String, String]
  57
  58         # The arguments passed with the POST or GET method (with a priority on POST)
  59         var all_args = new HashMap[String, String]
  60 end
  61
  62 # Utility class to parse a request string and build a `HttpRequest`
  63 #
  64 # The main method is `parse_http_request`.
  65 class HttpRequestParser
  66         # The current `HttpRequest` under construction
  67         private var http_request: HttpRequest is noinit
  68
  69         # Untreated body
  70         private var body = ""
  71
  72         # Lines of the header
  73         private var header_fields = new Array[String]
  74
  75         # Words of the first line
  76         private var first_line = new Array[String]
  77
  78         init do end
  79
  80         fun parse_http_request(full_request: String): nullable HttpRequest
  81         do
  82                 clear_data
  83
  84                 var http_request = new HttpRequest
  85                 self.http_request = http_request
  86
  87                 segment_http_request(full_request)
  88
  89                 # Parse first line, looks like "GET dir/index.html?user=xymus HTTP/1.0"
  90                 if first_line.length < 3 then
  91                         print "HTTP error: request first line apprears invalid: {first_line}"
  92                         return null
  93                 end
  94                 http_request.method = first_line[0]
  95                 http_request.url = first_line[1]
  96                 http_request.http_version = first_line[2]
  97
  98                 # GET args
  99                 if http_request.url.has('?') then
 100                         http_request.uri = first_line[1].substring(0, first_line[1].index_of('?'))
 101                         http_request.query_string = first_line[1].substring_from(first_line[1].index_of('?')+1)
 102
 103                         var parse_url = parse_url
 104                         http_request.get_args = parse_url
 105                         http_request.all_args.recover_with parse_url
 106                 else
 107                         http_request.uri = first_line[1]
 108                 end
 109
 110                 # POST args
 111                 if http_request.method == "POST" then
 112                         var lines = body.split_with('&')
 113                         for line in lines do if not line.trim.is_empty then
 114                                 var parts = line.split_once_on('=')
 115                                 if parts.length > 1 then
 116                                         var decoded = parts[1].replace('+', " ").from_percent_encoding
 117                                         if decoded == null then
 118                                                 print "decode error"
 119                                                 continue
 120                                         end
 121                                         http_request.post_args[parts[0]] = decoded
 122                                         http_request.all_args[parts[0]] = decoded
 123                                 else
 124                                         print "POST Error: {line} format error on {line}"
 125                                 end
 126                         end
 127                 end
 128
 129                 # Headers
 130                 for i in header_fields do
 131                         var temp_field = i.split_with(": ")
 132
 133                         if temp_field.length == 2 then
 134                                 http_request.header[temp_field[0]] = temp_field[1]
 135                         end
 136                 end
 137
 138                 # Cookies
 139                 if http_request.header.keys.has("Cookie") then
 140                         var cookie = http_request.header["Cookie"]
 141                         for couple in cookie.split_with(';') do
 142                                 var words = couple.trim.split_with('=')
 143                                 if words.length != 2 then continue
 144                                 http_request.cookie[words[0]] = words[1]
 145                         end
 146                 end
 147
 148                 return http_request
 149         end
 150
 151         private fun clear_data
 152         do
 153                 first_line.clear
 154                 header_fields.clear
 155         end
 156
 157         private fun segment_http_request(http_request: String): Bool
 158         do
 159                 var header_end = http_request.search("\r\n\r\n")
 160
 161                 if header_end == null then
 162                         header_fields = http_request.split_with("\r\n")
 163                 else
 164                         header_fields = http_request.substring(0, header_end.from).split_with("\r\n")
 165                         body = http_request.substring(header_end.after, http_request.length-1)
 166                 end
 167
 168                 # If a line of the http_request is long it may change line, it has " " at the
 169                 # end to indicate this. This section turns them into 1 line.
 170                 if header_fields.length > 1 and header_fields[0].has_suffix(" ") then
 171                         var temp_req = header_fields[0].substring(0, header_fields[0].length-1) + header_fields[1]
 172
 173                         first_line  = temp_req.split_with(' ')
 174                         header_fields.shift
 175                         header_fields.shift
 176
 177                         if first_line.length != 3 then return false
 178                 else
 179                         first_line = header_fields[0].split_with(' ')
 180                         header_fields.shift
 181
 182                         if first_line.length != 3 then return false
 183                 end
 184
 185                 # Cut off the header in lines
 186                 var pos = 0
 187                 while pos < header_fields.length do
 188                         if pos < header_fields.length-1 and header_fields[pos].has_suffix(" ") then
 189                                 header_fields[pos] = header_fields[pos].substring(0, header_fields[pos].length-1) + header_fields[pos+1]
 190                                 header_fields.remove_at(pos+1)
 191                                 pos = pos-1
 192                         end
 193                         pos = pos+1
 194                 end
 195
 196                 return true
 197         end
 198
 199         # Extract args from the URL
 200         private fun parse_url: HashMap[String, String]
 201         do
 202                 var query_strings = new HashMap[String, String]
 203
 204                 if http_request.url.has('?') then
 205                         var get_args = http_request.query_string.split_with("&")
 206                         for param in get_args do
 207                                 var key_value = param.split_with("=")
 208                                 if key_value.length < 2 then continue
 209                                 query_strings[key_value[0]] = key_value[1]
 210                         end
 211                 end
 212
 213                 return query_strings
 214         end
 215 end