Re: [LARTC] CBQ DEVICE BW?

[Srikanth <srikanth_w@xxxxxxxxxxxxxx>]

One more question,

Stef Coene wrote:
> On Friday 23 May 2003 10:44, Srikanth wrote:
> > Hi,
> >
> > The CBQ config file shud be some thing like this.
> >
> > DEVICE=eth0,10Mbit,1Mbit
> > RATE=50Kbit
> > WEIGHT=5Kbit
> >
> > Shall i hardcode the DEVICE BW as 10/100 Mbit
> > or
> > Shall i use any other tool like ethtool for getting this.
> > ethtool gives Speed: 10Mbps
> >
> > If so, how about, if i use some other Interfaces other than eth0,
> > like ppp0 or some other?
> >
> > C'd anybody can give a suggestion over this?
> >   
> Bandwidth should be the real physical bandwidth of the device.
How do i get the real physical bandwidth of the device?

The below program attached is giving the value 6, on my system.
In some other systems, it's giving 2 (don't know whether Kbps/Mbps).
> Stef
/*
 *    Gets the bandwidth of the interface.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <errno.h>

#include <db.h>
#include <sys/types.h>
#include <sys/time.h>
#include <fcntl.h>

#include <sys/socket.h>
#include <sys/ioctl.h>
//#include <netdb.h>

#include <linux/in.h>
#include <linux/if.h>
#include "ifstats.h"

extern int errno;

int
IFSGetBandwidth (if_stats_desc_struct * ifsd)
{
//#ifdef HAS_SIOCGIFINDEX
  int s, status;
  struct ifreq ifr;
  struct in_addr ina;
  if_ip_addr_union ip;


  if (ifsd == NULL)
    {
        printf("case 1\n");              
        return (-1);
    }     

  /* Must have a specified interface. */
  if (ifsd->interface == NULL)
    {             
        printf("case 2\n");              
    return (-1);
    }

  /* Create a UDP socket. */
  s = socket (AF_INET, SOCK_DGRAM, 0);
  if (s < 0)
    {             
        printf("case 3\n");              
    return (-1);
    }
  
  /* Set interface name explicitly from ifsd. */
  strncpy (ifr.ifr_name, ifsd->interface, IFNAMSIZ);
  ifr.ifr_name[IFNAMSIZ - 1] = '\0';

  /*   Get bandwidth of interface and put into interface request
     *            *   structure.
     *                     */
  status = ioctl(s, SIOCGIFINDEX, &ifr);

  /* Close socket. */
  close (s);

  /* ioctl() failed? */
  if (status < 0)
    {             
        perror("! Ioctl");        
      printf("case 4\n");              
    return (-1);
    }     

  ifsd->bandwidth = ifr.ifr_bandwidth;
 printf("Hello World\n"); 
  printf("Bandwidth: %i\n", ifsd->bandwidth);
  
//#endif /* HAS_SIOCGIFINDEX */

  return (0);
}


main ()
{
      int retVal;
    if_stats_desc_struct * ifsd;

    ifsd = (if_stats_desc_struct *) malloc(sizeof(if_stats_desc_struct));
    if (ifsd == NULL)
        perror("! Malloc");

    ifsd->interface = (char *) malloc(20);
    if (ifsd->interface == NULL)
        perror("! Malloc");
    strcpy(ifsd->interface, "eth0");    
      retVal = IFSGetBandwidth (ifsd);
    free(ifsd->interface);
    free(ifsd);
    printf("retVal = %d\n", retVal);
}



regards,
Srikanth.
>