server.c

Go to the documentation of this file.

/* serialT_proxy.c --- 
 * 
 * Filename: serialT_proxy.c
 * Description: 
 * Author: Bryce Himebaugh
 * Maintainer: 
 * Created: Tue Sep  5 08:46:53 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: */

/* A simple server in the internet domain using TCP
   The port number is passed as an argument */

#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 "ftdi_helper.h"
#include "server_command_line_parser.h"

#define STATE_DELAY_US 10000

void error(char *msg) {
    perror(msg);
    exit(1);
}

int delay_uS(int);

void sigproc();
void quitproc();
int print_sock_error(int);

int sockfd, portno, clilen;
int newsockfd=0;


int main(int argc, char *argv[]) {
  char buffer[256];
  struct sockaddr_in serv_addr, cli_addr;
  int n;
  
  int select_status;
  fd_set readfds;
  struct timeval to;
  
  enum {EUNCONNECTED,EREAD,FTDI,EWRITE};
  static int bridge_state=EUNCONNECTED; 

  char local_buffer[QUEUE_LENGTH];
  int read_chars=0;
  int write_chars=0;

  command_options_t options;
  unsigned int yes=1;

  // Setup signal handlers 
  signal(SIGINT,sigproc);
  signal(SIGQUIT,quitproc);

  // Handle Command Line Options
  init_command_line_options(&options);
  command_line_parser (argc, argv, &options);
  
  // Initialize the FTDI console channel 
  if (ftd2xx_init(ftd2xx_console_desc,!options.attach)) {
    printf("Initialization Failed\n");
    return (1);
  }
 
  // Setup to listen on the socket
  sockfd = socket(AF_INET, SOCK_STREAM, 0);        // Load file descriptor, sockfd
  if (sockfd < 0) {
    error("ERROR opening socket");
  }
  
/*   if (setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes))<0) { */
/*     perror("Reusing ADDR failed"); */
/*     exit(1); */
/*   } */
  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) {
    error("ERROR on binding");
  }
  listen(sockfd,5);
  
  while (1) {
    switch (bridge_state) {
    case EUNCONNECTED:
      printf("Waiting for a connection on port %d...",options.port);
      fflush(stdout);
      newsockfd = accept(sockfd,(struct sockaddr *) &cli_addr, &clilen);
      printf("Connection Accepted from %s\n",inet_ntoa(cli_addr.sin_addr));
      purge_ftdi();
      init_queue(&ftdi_tx_queue);
      init_queue(&ftdi_rx_queue);
      bridge_state=EREAD;
      break;
    case EREAD:
      bzero(buffer,256);
      FD_ZERO(&readfds);                    // clear the read file descriptor set
      FD_SET(newsockfd,&readfds);           // listen to the new socket for data 
      to.tv_sec = 0;
      to.tv_usec = 1000;    
      select_status=select(newsockfd+1,&readfds,NULL,NULL,&to);
      switch (select_status) {
      case -1:
        printf("Select Error\n");
        bridge_state=EUNCONNECTED;
        close(newsockfd);
        break;
      case 0:
        bridge_state=FTDI;
        break;
      default:
        bridge_state=FTDI;
        if (FD_ISSET(newsockfd,&readfds)) {
          n = read(newsockfd,buffer,255);
          if (n) {
            enqueue(&ftdi_tx_queue,buffer,n);
          } 
          else {
            bridge_state=EUNCONNECTED;
            close(newsockfd);
          }
        }
      }
      break;
    case FTDI:
      eval_ftdi_console();
      bridge_state=EWRITE;
      break;
    case EWRITE:
      bzero(local_buffer,QUEUE_LENGTH);
      if ((read_chars=dequeue(&ftdi_rx_queue,local_buffer,FTDI_RX_TRANSFER_SIZE))) {
        write_chars=write(newsockfd,local_buffer,read_chars);
      }
      bridge_state=EREAD;
      break;
    default:
      printf("Error: Unknown Communication State\n");
      exit(1);
      break;
    }
    delay_uS(STATE_DELAY_US);
  }
  return 0; 
}

int delay_uS(int uS) {
  struct timeval to;
  to.tv_sec = 0;
  to.tv_usec = uS;    
  select(0,NULL,NULL,NULL,&to);
  return (0);
}

void sigproc() {
  close(newsockfd);
  close(sockfd);
  exit(0);
}

void quitproc() {
  close(newsockfd);
  close(sockfd);
  exit(0);
}

int print_sock_error(int sock_error) {
  switch (sock_error) {
  case EBADF:
    printf("EBADF: The socket argument is not a valid file descriptor.\n");
    break;
  case EINVAL:
    printf("EINVAL: The socket shutdown method argument is  invalid.\n");
    break;
  case ENOTCONN:
    printf("ENOTCONN: The socket is not connected.\n");
    break;
  case ENOTSOCK:
    printf("ENOTCONN: The socket argument does not refer to a socket.\n");
    break;
  default:
    printf("%d:Unrecognized Socket Error\n",sock_error);
  }
  return(0);
}

/* server.c ends here */

---