git.sesse.net Git - casparcg/blob - protocol/amcp/AMCPProtocolStrategy.cpp

   1 /*
   2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
   3 *
   4 * This file is part of CasparCG (www.casparcg.com).
   5 *
   6 * CasparCG is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 3 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * CasparCG is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
  18 *
  19 * Author: Nicklas P Andersson
  20 */
  21
  22
  23 #include "../StdAfx.h"
  24
  25 #include "AMCPProtocolStrategy.h"
  26 #include "amcp_shared.h"
  27 #include "AMCPCommand.h"
  28 #include "AMCPCommandQueue.h"
  29 #include "amcp_command_repository.h"
  30
  31 #include <stdio.h>
  32 #include <string.h>
  33 #include <algorithm>
  34 #include <cctype>
  35 #include <future>
  36
  37 #include <core/help/help_repository.h>
  38 #include <core/help/help_sink.h>
  39
  40 #include <boost/algorithm/string/trim.hpp>
  41 #include <boost/algorithm/string/split.hpp>
  42 #include <boost/algorithm/string/replace.hpp>
  43 #include <boost/lexical_cast.hpp>
  44
  45 #if defined(_MSC_VER)
  46 #pragma warning (push, 1) // TODO: Legacy code, just disable warnings
  47 #endif
  48
  49 namespace caspar { namespace protocol { namespace amcp {
  50
  51 using IO::ClientInfoPtr;
  52
  53 template <typename Out, typename In>
  54 bool try_lexical_cast(const In& input, Out& result)
  55 {
  56         Out saved = result;
  57         bool success = boost::conversion::detail::try_lexical_convert(input, result);
  58
  59         if (!success)
  60                 result = saved; // Needed because of how try_lexical_convert is implemented.
  61
  62         return success;
  63 }
  64
  65 struct AMCPProtocolStrategy::impl
  66 {
  67 private:
  68         std::vector<AMCPCommandQueue::ptr_type>         commandQueues_;
  69         spl::shared_ptr<amcp_command_repository>        repo_;
  70
  71 public:
  72         impl(const std::wstring& name, const spl::shared_ptr<amcp_command_repository>& repo)
  73                 : repo_(repo)
  74         {
  75                 commandQueues_.push_back(spl::make_shared<AMCPCommandQueue>(L"General Queue for " + name));
  76
  77                 for (int i = 0; i < repo_->channels().size(); ++i)
  78                 {
  79                         commandQueues_.push_back(spl::make_shared<AMCPCommandQueue>(
  80                                         L"Channel " + boost::lexical_cast<std::wstring>(i + 1) + L" for " + name));
  81                 }
  82         }
  83
  84         ~impl() {}
  85
  86         enum class error_state {
  87                 no_error = 0,
  88                 command_error,
  89                 channel_error,
  90                 parameters_error,
  91                 unknown_error,
  92                 access_error
  93         };
  94
  95         struct command_interpreter_result
  96         {
  97                 std::shared_ptr<caspar::IO::lock_container>     lock;
  98                 std::wstring                                                            command_name;
  99                 AMCPCommand::ptr_type                                           command;
 100                 error_state                                                                     error                   = error_state::no_error;
 101                 std::shared_ptr<AMCPCommandQueue>                       queue;
 102         };
 103
 104         //The paser method expects message to be complete messages with the delimiter stripped away.
 105         //Thesefore the AMCPProtocolStrategy should be decorated with a delimiter_based_chunking_strategy
 106         void Parse(const std::wstring& message, ClientInfoPtr client)
 107         {
 108                 CASPAR_LOG_COMMUNICATION(info) << L"Received message from " << client->address() << ": " << message << L"\\r\\n";
 109
 110                 command_interpreter_result result;
 111                 if(interpret_command_string(message, result, client))
 112                 {
 113                         if(result.lock && !result.lock->check_access(client))
 114                                 result.error = error_state::access_error;
 115                         else
 116                                 result.queue->AddCommand(result.command);
 117                 }
 118
 119                 if (result.error != error_state::no_error)
 120                 {
 121                         std::wstringstream answer;
 122
 123                         switch(result.error)
 124                         {
 125                         case error_state::command_error:
 126                                 answer << L"400 ERROR\r\n" << message << "\r\n";
 127                                 break;
 128                         case error_state::channel_error:
 129                                 answer << L"401 " << result.command_name << " ERROR\r\n";
 130                                 break;
 131                         case error_state::parameters_error:
 132                                 answer << L"402 " << result.command_name << " ERROR\r\n";
 133                                 break;
 134                         case error_state::access_error:
 135                                 answer << L"503 " << result.command_name << " FAILED\r\n";
 136                                 break;
 137                         case error_state::unknown_error:
 138                                 answer << L"500 FAILED\r\n";
 139                                 break;
 140                         default:
 141                                 CASPAR_THROW_EXCEPTION(programming_error()
 142                                                 << msg_info(L"Unhandled error_state enum constant " + boost::lexical_cast<std::wstring>(static_cast<int>(result.error))));
 143                         }
 144                         client->send(answer.str());
 145                 }
 146         }
 147
 148 private:
 149         bool interpret_command_string(const std::wstring& message, command_interpreter_result& result, ClientInfoPtr client)
 150         {
 151                 try
 152                 {
 153                         std::list<std::wstring> tokens;
 154                         tokenize(message, tokens);
 155
 156                         // Discard GetSwitch
 157                         if (!tokens.empty() && tokens.front().at(0) == L'/')
 158                                 tokens.pop_front();
 159
 160                         std::wstring request_id;
 161
 162                         if (!tokens.empty() && boost::iequals(tokens.front(), L"REQ"))
 163                         {
 164                                 tokens.pop_front();
 165
 166                                 if (tokens.empty())
 167                                 {
 168                                         result.error = error_state::parameters_error;
 169                                         return false;
 170                                 }
 171
 172                                 request_id = tokens.front();
 173                                 tokens.pop_front();
 174                         }
 175
 176                         // Fail if no more tokens.
 177                         if (tokens.empty())
 178                         {
 179                                 result.error = error_state::command_error;
 180                                 return false;
 181                         }
 182
 183                         // Consume command name
 184                         result.command_name = boost::to_upper_copy(tokens.front());
 185                         tokens.pop_front();
 186
 187                         // Determine whether the next parameter is a channel spec or not
 188                         int channel_index = -1;
 189                         int layer_index = -1;
 190                         std::wstring channel_spec;
 191
 192                         if (!tokens.empty())
 193                         {
 194                                 channel_spec = tokens.front();
 195                                 std::wstring channelid_str = boost::trim_copy(channel_spec);
 196                                 std::vector<std::wstring> split;
 197                                 boost::split(split, channelid_str, boost::is_any_of("-"));
 198
 199                                 // Use non_throwing lexical cast to not hit exception break point all the time.
 200                                 if (try_lexical_cast(split[0], channel_index))
 201                                 {
 202                                         --channel_index;
 203
 204                                         if (split.size() > 1)
 205                                                 try_lexical_cast(split[1], layer_index);
 206
 207                                         // Consume channel-spec
 208                                         tokens.pop_front();
 209                                 }
 210                         }
 211
 212                         bool is_channel_command = channel_index != -1;
 213
 214                         // Create command instance
 215                         if (is_channel_command)
 216                         {
 217                                 result.command = repo_->create_channel_command(result.command_name, client, channel_index, layer_index, tokens);
 218
 219                                 if (result.command)
 220                                 {
 221                                         result.lock = repo_->channels().at(channel_index).lock;
 222                                         result.queue = commandQueues_.at(channel_index + 1);
 223                                 }
 224                                 else // Might be a non channel command, although the first argument is numeric
 225                                 {
 226                                         // Restore backed up channel spec string.
 227                                         tokens.push_front(channel_spec);
 228                                         result.command = repo_->create_command(result.command_name, client, tokens);
 229
 230                                         if (result.command)
 231                                                 result.queue = commandQueues_.at(0);
 232                                 }
 233                         }
 234                         else
 235                         {
 236                                 result.command = repo_->create_command(result.command_name, client, tokens);
 237
 238                                 if (result.command)
 239                                         result.queue = commandQueues_.at(0);
 240                         }
 241
 242                         if (!result.command)
 243                                 result.error = error_state::command_error;
 244                         else
 245                         {
 246                                 std::vector<std::wstring> parameters(tokens.begin(), tokens.end());
 247
 248                                 result.command->parameters() = std::move(parameters);
 249
 250                                 if (result.command->parameters().size() < result.command->minimum_parameters())
 251                                         result.error = error_state::parameters_error;
 252                         }
 253
 254                         if (result.command)
 255                                 result.command->set_request_id(std::move(request_id));
 256                 }
 257                 catch (std::out_of_range&)
 258                 {
 259                         CASPAR_LOG(error) << "Invalid channel specified.";
 260                         result.error = error_state::channel_error;
 261                 }
 262                 catch (...)
 263                 {
 264                         CASPAR_LOG_CURRENT_EXCEPTION();
 265                         result.error = error_state::unknown_error;
 266                 }
 267
 268                 return result.error == error_state::no_error;
 269         }
 270
 271         template<typename C>
 272         std::size_t tokenize(const std::wstring& message, C& pTokenVector)
 273         {
 274                 //split on whitespace but keep strings within quotationmarks
 275                 //treat \ as the start of an escape-sequence: the following char will indicate what to actually put in the string
 276
 277                 std::wstring currentToken;
 278
 279                 bool inQuote = false;
 280                 bool getSpecialCode = false;
 281
 282                 for(unsigned int charIndex=0; charIndex<message.size(); ++charIndex)
 283                 {
 284                         if(getSpecialCode)
 285                         {
 286                                 //insert code-handling here
 287                                 switch(message[charIndex])
 288                                 {
 289                                 case L'\\':
 290                                         currentToken += L"\\";
 291                                         break;
 292                                 case L'\"':
 293                                         currentToken += L"\"";
 294                                         break;
 295                                 case L'n':
 296                                         currentToken += L"\n";
 297                                         break;
 298                                 default:
 299                                         break;
 300                                 };
 301                                 getSpecialCode = false;
 302                                 continue;
 303                         }
 304
 305                         if(message[charIndex]==L'\\')
 306                         {
 307                                 getSpecialCode = true;
 308                                 continue;
 309                         }
 310
 311                         if(message[charIndex]==L' ' && inQuote==false)
 312                         {
 313                                 if(!currentToken.empty())
 314                                 {
 315                                         pTokenVector.push_back(currentToken);
 316                                         currentToken.clear();
 317                                 }
 318                                 continue;
 319                         }
 320
 321                         if(message[charIndex]==L'\"')
 322                         {
 323                                 inQuote = !inQuote;
 324
 325                                 if(!currentToken.empty() || !inQuote)
 326                                 {
 327                                         pTokenVector.push_back(currentToken);
 328                                         currentToken.clear();
 329                                 }
 330                                 continue;
 331                         }
 332
 333                         currentToken += message[charIndex];
 334                 }
 335
 336                 if(!currentToken.empty())
 337                 {
 338                         pTokenVector.push_back(currentToken);
 339                         currentToken.clear();
 340                 }
 341
 342                 return pTokenVector.size();
 343         }
 344 };
 345
 346 AMCPProtocolStrategy::AMCPProtocolStrategy(const std::wstring& name, const spl::shared_ptr<amcp_command_repository>& repo)
 347         : impl_(spl::make_unique<impl>(name, repo))
 348 {
 349 }
 350 AMCPProtocolStrategy::~AMCPProtocolStrategy() {}
 351 void AMCPProtocolStrategy::Parse(const std::wstring& msg, IO::ClientInfoPtr pClientInfo) { impl_->Parse(msg, pClientInfo); }
 352
 353
 354 }       //namespace amcp
 355 }}      //namespace caspar