socket_comm.c

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/* socket_comm.c --- 
 * 
 * Filename: socket_comm.c
 * Description: 
 * Author: Bryce Himebaugh
 * Maintainer: 
 * Created: Tue Oct  3 10:53:28 2006
 * Version: 
 * Last-Updated: 
 *           By: 
 *     Update #: 0
 * Keywords: 
 * Compatibility: 
 * 
 */

/* Commentary: 
 * 
 * 
 * 
 */

/* Change log:
 * 
 * 
 */

/* This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* Code: */

#include <stdio.h>
#include <sys/types.h> 
#include <sys/socket.h>
#include <netinet/in.h>
#include <strings.h>
#include <string.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <pthread.h>
#include <fcntl.h>
#include "command_line_parser.h"
#include "frame_comm.h"

int socket_comm(command_options_t *options) {
  static struct sockaddr_in serv_addr, cli_addr;
  enum {INIT,UNCONNECTED,QUEUE_FRAME};
  static int bridge_state=INIT; 
  int oldopts;
  static int sockfd=0;
  static int clilen=0;
  static int newsockfd=0;
  char buffer[256];
  int n;
  char write_buffer[500]; 
  int write_chars;

  switch (bridge_state) {
  case INIT:
    sockfd = socket(AF_INET, SOCK_STREAM, 0);        // Load file descriptor, sockfd
    if (sockfd < 0) {
      printf("ERROR opening socket\n");
        exit(0);
    }
    oldopts = fcntl(sockfd, F_GETFL, 0);
    fcntl(sockfd, F_SETFL, oldopts | O_NONBLOCK);
    bzero((char *) &serv_addr, sizeof(serv_addr));   // zero the 
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    serv_addr.sin_port = htons(options->port);
    if (bind(sockfd, (struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) {
      printf("ERROR on binding\n");
      exit(0);
    }
    listen(sockfd,5);
    bridge_state=UNCONNECTED;
    break;
  case UNCONNECTED:
    errno=0;
    if ((newsockfd = accept(sockfd,(struct sockaddr *) &cli_addr, &clilen))==-1) {
      if (errno==EWOULDBLOCK) {
      }
    }
    else {
      bridge_state=QUEUE_FRAME;
      oldopts = fcntl(newsockfd, F_GETFL, 0);
      fcntl(newsockfd, F_SETFL, oldopts | O_NONBLOCK);
    }
    break;
  case QUEUE_FRAME:
    bzero(buffer,256);
    n = read(newsockfd,buffer,255);
    if (n<0) {
      // no data available
      writeMessage(&msg,write_buffer);
      write_chars=write(newsockfd,write_buffer,strlen(write_buffer));
    }
    else if (n==0) {
      // socket closed at the other end
      close(newsockfd);
      bridge_state=UNCONNECTED;
    }
    else {
      // data of length n was read into the buffer
      // take this data and load it into the struct 
    }
    break;
  default:
    printf("Error: Unknown Communication State\n");
    exit(1);
    break;
  }
  return 0;    
}




/* socket_comm.c ends here */

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