simple_net.c

/* code taken and adapted from http://www.ecst.csuchico.edu/~beej/guide/net/ */

#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <signal.h>
#include <errno.h>

#include "simple_net.h"

int create_service(unsigned short port, int queue_size)
{
   int fd;  /* listen on sock_fd, new connection on new_fd */
   struct sockaddr_in local_addr;    /* my address information */
   int yes=1;

   if ((fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
   {
      return -1;
   }

   if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1)
   {
      return -1;
   }
        
   local_addr.sin_family = AF_INET;         /* host byte order */
   local_addr.sin_port = htons(port);       /* short, network byte order */
   local_addr.sin_addr.s_addr = INADDR_ANY; /* automatically fill with my IP */
   memset(&(local_addr.sin_zero), '\0', 8); /* zero the rest of the struct */

   if (bind(fd, (struct sockaddr *)&local_addr, sizeof(struct sockaddr)) == -1)
   {
      return -1;
   }

   if (listen(fd, queue_size) == -1)
   {
      return -1;
   }

   return fd;
}

int accept_connection(int fd)
{
   int new_fd;
   struct sockaddr_in remote_addr;
   socklen_t size = sizeof(struct sockaddr_in);

   errno = EINTR;
   while (errno == EINTR)
   {
      if ((new_fd = accept(fd, (struct sockaddr*)&remote_addr, &size)) == -1
         && errno != EINTR)
      {
         return -1;
      }
      else if (new_fd != -1)
      {
         break;
      }
   }

   return new_fd;
}