Get MAC address - no SIOCGIFHWADDR available

QNX DEVELOPERS General Programming
1

Hi,

using linux it is quite simple to retrieve the MAC address of an ethernet card: ioctl(s, SIOCGIFHWADDR, &ifr) returns it in ifr. Unfortunately the flag SIOCGIFHWADDR, doesn’T seem to exist in QNX.

So how can I retrieve the MAC address here?

Elmi

2

getifaddrs() / freeifaddrs()

Regards,

-seanb

3

I needed to do this. getifaddrs() is the place to start. It returns multiple entries for each item, en0, en1, etc. Also, the mac address is returned in a sockaddr structure, but at an offset. I couldn’t find any documentation on this but it was pretty obvious when you find it.

4

@maschoen: othermark.livejournal.com/3005.html

5

i am trying to use getifaddrs to get mac ip but when i compile the code it says error:undefined reference to getifaddrs i have included the header files …can anyone help me out

6

Amit,

Are you getting these errors at compile time or link time?

If it’s at link time did you remember to add ‘-l socket’ to include the socket library?

Tim

7

Tim ,

I have included that -l socket option,error is coming in compile time

#include <sys/socket.h>
#include <sys/types.h>
#include <netdb.h>
#include <ifaddrs.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include<netinet/in.h>

int main(int argc, char *argv[]) {

struct ifaddrs *ifaddr;
int family, s;

if (getifaddrs(&ifaddr) == -1) {
perror("getifaddrs");
exit(1);

}
/*collecting the data recived
*/
struct ifaddrs *ifa = ifaddr;

for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
if (ifa->ifa_addr != NULL) {
  int family = ifa->ifa_addr->sa_family;
  if (family == AF_INET || family == AF_INET6) {
    char ip_addr[NI_MAXHOST];
    int s = getnameinfo(ifa->ifa_addr,
                        ((family == AF_INET) ? sizeof(struct sockaddr_in) :
                                               sizeof(struct sockaddr_in6)),
                        ip_addr, sizeof(ip_addr), NULL, 0, NI_NUMERICHOST);
    if (s != 0) {
      printf("getnameinfo() failed: %s\n", gai_strerror(s));
      exit(1);
    } else {
      printf("%-7s: %s\n", ifa->ifa_name, ip_addr);
    }
  }/* else if (family == AF_PACKET) {
    struct rtnl_link_stats *stats = ifa->ifa_data;
    printf("%-7s:\n"
           "\ttx_packets = %12u, rx_packets = %12u\n"
           "\ttx_bytes   = %12u, rx_bytes   = %12u\n",
           ifa->ifa_name,
           stats->tx_packets, stats->rx_packets,
           stats->tx_bytes, stats->rx_bytes);
  } else {
    printf("%-7s: family=%d\n", ifa->ifa_name, family);
  }

*/
}
}

i am getting output:
lo0:123.0.0.1
en0:168.12.12.33

how to get the Mac address from abhove program…plz help

freeifaddrs(ifaddr);
exit(0);
}

8

Amit,

Do you not have ifaddrs.h in your /usr/include directory? It’s there for me so I am not sure why your compilation isn’t working.

This link might help (This assumes you are running QNX 6.5)

qnx.com/support/knowledgebas … 000000mosy

Tim

9

Hi,

thanks for the reply,and the link u have send i try it.

But i used the below code to find the mac id.Is there any difference b/w 2,and which one is better

#include <sys/ioctl.h>
#include <net/if.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
#include<hw/nicinfo.h>
#include<sys/dcmd_io-net.h>
#include<stdlib.h>
#include<stdio.h>
#include<fcntl.h>

int main()
{
nic_config_t nicconfig;
int fd,i;
char mac[10];
fd=open("/dev/io-net/en0",O_RDONLY);
devctl(fd, DCMD_IO_NET_GET_CONFIG, &nicconfig,sizeof(nicconfig), NULL);
printf(“Device id=”);
for (i=0;i<8;i++)
{
printf("%x",nicconfig.permanent_address[i]);
}
printf("\n");
return 1;
}