Re: how to read data with g_io_read_channel throwed it through a normal socket

[James Scott Jr <skoona verizon net>]

On Thu, 2007-04-12 at 13:36 -0700, nahuel9728 wrote:

> Hi everyone. Im developing a interface for a server program and I have some
> problems.Step by step:
> - I put the server in listen:
>   fd_dealer2server=socket......
>   bind....
>   listen(fd_dealer2server,MAX_CON)
>
> - I create a channel and I add a watch to the the port binded for everytime
> a data goes in
> io = g_io_channel_unix_new (fd_dealer2server);
> if (!g_io_add_watch (io, G_IO_IN, (GIOFunc) my_func, NULL)){g_error ....}
>
> -Tll here everything its ok.... Later in my_func:
> static void my_func (GIOChannel *gio, GIOCondition condition, gpointer
> data){
>         guint mensaje[1];
>       gsize bytes_read;
>          if(g_io_channel_read (gio, (gchar *) mensaje , sizeof(mensaje) , &
> bytes_read) != G_IO_ERROR_NONE){
>                       g_warning("Error\n");
>               }
>
> And Finally I have my client binded to the shame port....
>         fd=socket
>         connect(fd,
>         int sms = atoi(argv[2]);
>         send( fd, &sms, sizeof(int) ,0);
>
> It catch the event G_IO_IN but g_io_read doesnt works..Always get error. Any
> hint???
> Regards to every1, Nahuel


Nahuel,

You need to perform the socket accept() before the
g_io_channel_unix_new() is called.  

The http://gfhcmd.sourceforge.net/ package contains a gfhcmd server
module and the gfhcmc contains its matching client; I offer them as a
example of using g_io_channel... with sockets and gtk/glib.

Here is an example routine that picks up where you left off (at the
listen).  You should find the select(),  then accept(), then the
g_io_channel_unix_new() calls.  

[CODE]
/*     
 * Accept a TCP connection, waiting for upto 80 seconds.
 * Returns NULL on error, or connected GIOChannel
 * 
 */
extern GIOChannel *sknet_net_accept(PSKCOMM psk)
{
   socklen_t clilen = sizeof(struct sockaddr_in);
   int            newfd;
   struct sockaddr_in client_addr;
   GIOChannel    *ioc = NULL;
   gint           rc = 0, ecount = 0;
   fd_set         fdset;
   struct timeval timev, *tv = NULL;


   g_return_val_if_fail (psk != NULL, NULL);

   /*
    * Wait on an incoming connection 
    */
   ecount = 0;
   tv = &timev;
   rc = 0;
   while ( rc <= 0) {
      timev.tv_sec = 8;
      timev.tv_usec = 0;
      FD_ZERO(&fdset);
      FD_SET(psk->fd_server, &fdset);
      if ( ecount > 10 ) {
          g_snprintf(psk->ch_error_msg, sizeof(psk->ch_error_msg), 
                     "accept select(failed), retry=%d {%s}",
                     ecount, g_strerror(errno));
           psk->ioc = NULL;
           return NULL;
      }
      rc = select(psk->fd_server+1, &fdset, NULL, NULL, tv);
      if ( rc == 0 ) { continue; } /* timed out */
      if ( rc == -1 ) { 
          g_snprintf(psk->ch_error_msg, sizeof(psk->ch_error_msg), 
                     "tv.sec=%d, retrying=%d {%s}",
                     (int)timev.tv_sec, ecount, g_strerror(errno));
          sknet_util_log_msg("sknet_net_accept", "accept select()
failing", 
                             psk->ch_error_msg);

          g_usleep(1000000); 
      } /* error */  

      ecount++;     
   } /* end-while */

   /*
    * Prepare to accept the connection
    */
   memset (&client_addr, 0, sizeof(struct sockaddr_in));

   newfd = accept(psk->fd_server, (struct sockaddr *)&client_addr,
&clilen);

   if (newfd < 0) {
       sknet_util_log_msg("Net_Accept issue ", "newfd<0", (gchar
*)g_strerror(errno));
       g_snprintf(psk->ch_error_msg,
sizeof(psk->ch_error_msg),"sknet_net_accept(%s)",
                 (gchar *) g_strerror (errno));
       psk->ioc = NULL;          
      return NULL;                 /* error */
   }

   /*
    *  get session partners name */
   getnameinfo ((struct sockaddr *)&client_addr, clilen, 
                psk->ch_ip_client, sizeof(psk->ch_ip_client),
                psk->ch_ip_client_port, sizeof(psk->ch_ip_client_port), 
                NI_NUMERICSERV);

   ioc = g_io_channel_unix_new( newfd);
   g_io_channel_set_encoding (ioc, NULL, NULL);   
   g_io_channel_set_buffered (ioc, FALSE);

   psk->ioc = ioc;
   return ioc;
}

[/CODE]