Colony

/** 

 * @file ColonetServer.cpp

 *

 * @brief colonet_server - primary server application for Colonet

 *

 * @author Jason Knichel

 * @author Eugene Marinelli

 * @date 10/31/06

 */

#include <colonet_wireless.h>

#include <sys/select.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <errno.h>

#include <arpa/inet.h>

#include <fcntl.h>

#include <colonet_wireless.h>

#include "includes/ColonetServer.h"

#include "includes/ConnectionPool.h"

#include "includes/client.h"

#include "includes/options.h"

#include "includes/Logging.h"

#define LISTEN_BACKLOG 5

#define LOG_BUFFER_LENGTH 128

ConnectionPool * connection_pool;

/**

 * @brief Default constructor for ColonetServer

 */

ColonetServer::ColonetServer(): logger("logFile.txt") {

  listen_socket = 0;

}

/**

 * @brief Destructor for ColonetServer

 */

ColonetServer::~ColonetServer() {

}

/**

 * @brief Initializes the various elements needed for the server to run

 *

 * @param argc The number of command line arguments passed to the program

 * @param argv The command line arguments passed to the program

 *

 * @return 0 on success, negative error code on failure

 */

int ColonetServer::initialize_server(int argc, char * argv[]) {

  printf("Initializing Server...\n");

  parseCmdLine(argc, argv);

  if (initialize_connection(optionsG.listen_port) < 0) {

    return -1;

  }

  if (initialize_wireless() < 0) {

    fprintf(stderr, "%s: initWireless failed\n", __FUNCTION__);

    return -1;

  }

  return 0;

}

/**

 * @brief Starts the server listening on the socket that was opened for listening

 *

 * @return 0 on success, negative error code on failure

 */

int ColonetServer::start_listening() {

  if (listen(listen_socket, LISTEN_BACKLOG) < 0) {

    log_error("\t\nThere was an error telling the socket to "

              "listen for connections from clients.  Terminating Server...\n");

    return -1;

  }

  return 0;

}

/**

 * @brief Logs an error message to the log file

 */

int ColonetServer::log_error(char * error_message) {

  return logger.logMessage(LOG_TYPE_ERROR, error_message);

}

/**

 * @brief Logs a message to the log file

 */

int ColonetServer::log_message(char * message) {

  return logger.logMessage(LOG_TYPE_MESSAGE, message);

}

/**

 * @brief Starts the server running (starts an infinite loop)

 */

int ColonetServer::run_server() {

  connection_pool.set_listen_socket_in_ready_set(listen_socket);

  //TODO: why is all of this in that if statement and not just conn_pool.maxfd = listen_socket ?

  if (listen_socket > connection_pool.get_max_file_descriptor()) {

    connection_pool.set_max_file_descriptor(listen_socket);

    int accept_socket = 0;

    struct sockaddr_in client_addr;

    socklen_t client_addr_size = sizeof(client_addr);

    struct timeval select_timeout;

    memset(&select_timeout, 0, sizeof(select_timeout));

    log_message("Server initialized.  About to start listening for connections");

    while(1) {

      connection_pool.perform_select(listen_socket, &select_timeout);

      //either no descriptors are ready or there was an error

      //TODO: check for specific errors

      if (connection_pool.get_number_clients_ready() <= 0) {

        continue;

      }

      if (connection_pool.is_socket_ready_to_read(listen_socket)) {

        printf("Something is trying to connect...\n");

        if ((accept_socket = accept(listen_socket, (struct sockaddr*) &client_addr, &client_addr_size)) < 0) {

          if (errno == EMFILE) {

            printf("\tWhen attempting to accept a connection, "

                   "reached the per process limit of file descriptors."

                   "  Dropping the new connection.\n");

            continue;

          } else {

            printf("\tThere was an error when attempting to accept a "

                   "connection");

          }

          continue;

        }

        char log_buffer[LOG_BUFFER_LENGTH];

        snprintf(log_buffer, LOG_BUFFER_LENGTH, "Client at address %s attempting to connect.", 

                 inet_ntoa(client_addr.sin_addr));

        logger.logMessage(LOG_TYPE_CONNECT, log_buffer);

        if (connection_pool.add_client(accept_socket) < 0) {

          printf("\tThere was an error when trying to add a client to the connection pool.");

          continue;

        }

        snprintf(log_buffer, LOG_BUFFER_LENGTH, "Client at address %s successfully added to connection pool.", 

                 inet_ntoa(client_addr.sin_addr));

        logger.logMessage(LOG_TYPE_CONNECT, log_buffer);

      }

      if (connection_pool.check_clients(wireless) < 0) {

        printf("\tThere was an error trying to update the clients.");

        continue;

      }

    }

  }

  return 0;

}

/**

 * @todo This method is here because the wireless message handler has a dependency on the connection_pool

 *  This should be removed when that dependency is broken

 *

 * @return A pointer to the connection pool

 */

ConnectionPool * ColonetServer::get_connection_pool_pointer() {

  return &connection_pool;

}

/**

 * @brief Initializes the wireless

 *

 * @return 0 on success, negative error code on error

 */

int ColonetServer::initialize_wireless() {

  char* log_filename = NULL;

  if (optionsG.logging_enabled) {

    log_filename = optionsG.log_filename;

  }

  wireless = new ColonetWireless(optionsG.wireless_port, 

                                 wirelessMessageHandler, log_filename, 

                                 /*!optionsG.listener_mode*/false, true);

  //Note: last arg set to true ignores token ring;  in general, this should

  //probably be false (changed for demo purposes)

  if (!wireless->run_listener_thread()) {

    return -1;

  }

  return 0;

}

/**

 * @brief Initialize a connection to listen on

 *

 * @port The port to try to open to listen on

 *

 * @return 0 on success, negative error code on error

 */

int ColonetServer::initialize_connection(int port) {

  printf("Initializing connection that will be used to listen for " 

         "clients...\n");

  int options = 1;

  struct sockaddr_in my_address;

  //get a socket fd

  if ((listen_socket = socket(AF_INET, SOCK_STREAM, 0)) < 0) {

    printf("\tThere was an error creating a socket\n");

    return -1;

  }

  //set up the address struct

  memset(&my_address,'\0',sizeof(my_address));

  my_address.sin_family = AF_INET;

  my_address.sin_addr.s_addr = htonl(INADDR_ANY);

  my_address.sin_port = htons(port);

  setsockopt(listen_socket, SOL_SOCKET, SO_REUSEADDR, &options, sizeof(options));

  //get the current socket options

  if ((options = fcntl(listen_socket, F_GETFL)) < 0) {

    printf("\tThere was an error getting the socket options.\n");

    return -1;

  }

  //set the socket to non blocking

  options = (options | O_NONBLOCK);

  if (fcntl(listen_socket, F_SETFL, options) < 0) {

    printf("\tThere was an error setting the socket to be non blocking.\n");

    return -1;

  }

  //bind the socket to listen on the specified port

  if (bind(listen_socket, (struct sockaddr *) &my_address, sizeof(my_address)) < 0) {

    printf("\tThere was an error binding the socket\n");

    return -1;

  }

  return 0;

}

/**

 * @brief The main function of the server

 *

 * @param argc The number of command line arguments passed to the program

 * @param argv The command line arguments passed to the program

 *

 * @return 0 on success, negative error code on error

 */

int main(int argc, char** argv) {

  ColonetServer colonet_server;

  connection_pool = colonet_server.get_connection_pool_pointer();

  if (colonet_server.initialize_server(argc, argv) < 0) {

    colonet_server.log_error("\t\nThere was an error initializing the server. "

                             "Terminating server...\n");

    return -1;

  }

  if (colonet_server.start_listening() < 0) {

    return -1;

  }

  colonet_server.run_server();

  return 0;

}

//this is old code that was commented out that I didn't want to delete yet

/*

int parseCommandLine(int argc, char * argv[], commandParams_t * params)

{

  printf("Parsing Command Line...\n");

  if (!params)

    return -1;

  //if no command line parameters were specified, set to defaults

  if (argc == 1) {

    printf("No port was specified for listening for client connections."

           "  Defaulting to %d\n", DEFAULTPORT);

    params->listenPort = DEFAULTPORT;

  }

  if (!argv)

    return -1;

  int i;

  for (i = 1; i < argc; i++) {

    char * temp = argv[i];

    if (temp[0] != '-')

      {

        printUsage(argv[0]);

        return -1;

      }

    switch(temp[1])

      {

      case 'h': printUsage(argv[0]);

        break;

      case 'p': 

        {

          if (i >= argc-1)

            {

              printUsage(argv[0]);

              return -1;

            }

          i++;

          char * portString = argv[i];

          char * endptr = NULL;

          int port = strtol(portString, &endptr, 10);

          if (*endptr != '\0')

            {

              printf("Invalid port specified...%s, %d\n", endptr, port);

              return -1;

            }

          if (port < SMALLEST_POSS_LISTEN_PORT)

            {

              printf("You cannot listen on a port less than %d.\n",

                     SMALLEST_POSS_LISTEN_PORT);

              return -1;

            }

          params->listenPort = port;

          printf("Setting port to listen on to %d.\n", params->listenPort);

        }

        break;

      default: printUsage(argv[0]);

        return -1;

        break;

      }

  }

  return 0;

}

*/