how to use ethtool_drvinfo to collect driver information for a network interface?

Question

I have a network interface that shows data as under:

driver: r8152 
version: v1.12.12
firmware-version: rtl8153a-4 v2 02/07/20
expansion-rom-version:
bus-info: usb-0000:00:14.0-9
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no

However I am unable to collect driver information via an ioctl call like this:

socketfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
if (socketfd == -1)
    printf ("error:socketfd no open");

struct ethtool_drvinfo drvrinfo = {0};
drvrinfo.cmd = ETHTOOL_GDRVINFO;
int x = ioctl(socketfd, SIOCETHTOOL, &drvrinfo);`

I am not sure of the exact flow as I am using it for the first time. Please help

Answer 1

Simple Linux dump of this info. Change enp0s5 to your interface name.

Sample output:

% ./get-driver-info
driver: virtio_net
version: 1.0.0
firmware-version:
expansion-rom-version:
bus-info: 0000:00:05.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-priv-flags: no

Linux source:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <linux/ethtool.h>
#include <linux/sockios.h>
#include <net/if.h>

int main() {
  char *devname = "enp0s5";
  struct ifreq sif;
  struct ethtool_drvinfo d;
  int ret;

  int sd = socket(AF_INET, SOCK_DGRAM, 0);

  if (sd < 0){
    printf("Error socket\n");
    exit(1);
  }

  memset(&sif, 0, sizeof(struct ifreq));
  strncpy(sif.ifr_name, devname, strlen(devname));

  d.cmd = ETHTOOL_GDRVINFO;
  sif.ifr_data = (caddr_t)&d;
  ret = ioctl(sd, SIOCETHTOOL, &sif);

  if(ret == -1){
    perror("ioctl");
    return 1;
  }

  printf("driver: %s\nversion: %s\n", d.driver, d.version);
  printf("firmware-version: %s\n", d.fw_version);
  printf("expansion-rom-version: %s\n", d.fw_version);
  printf("bus-info: %s\n", d.bus_info);
  printf("supports-statistics: %s\n", d.n_stats ? "yes" : "no");
  printf("supports-test: %s\n", d.testinfo_len ? "yes" : "no");
  printf("supports-eeprom-access: %s\n", d.eedump_len ? "yes" : "no");
  printf("supports-priv-flags: %s\n", d.n_priv_flags ? "yes" : "no");
}

This information isn't stored in the socket, but having an open socket is a convenient way to query for information from the kernel about a specific network interface.