DLI/Ethernet interface questions

[Jeff Michaud]

In article <810 at uhnix2.uh.edu>, jh at allez.uh.edu (Jeff Hayward) writes:
> How can I obtain the Ethernet address of a given interface?  

As promised, here is the sample program:

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <sys/ioctl.h>

main(argc, argv)
    int argc;
    char *argv[];
{
    struct ifdevea address;
    int sock;

    if( argc <= 1 ) {
        fprintf(stderr, "Usage: %s device\n", argv[0]);
        exit();
    }

    bzero(&address, sizeof(address));
    strcpy(address.ifr_name, argv[1]);

    sock = socket(AF_UNIX, SOCK_DGRAM, 0);
    if( sock < 0 ) {
        perror("socket(AF_UNIX, SOCK_DGRAM, 0)");
        exit();
    }

    if( ioctl(sock, SIOCRPHYSADDR, &address) < 0 ) {
        perror("ioctl(SIOCRPHYSADDR)");
        exit();
    }

    close(sock);

    printf("Current Physical Address: %02x-%02x-%02x-%02x-%02x-%02x\n",
        address.current_pa[0], address.current_pa[1], address.current_pa[2],
        address.current_pa[3], address.current_pa[4], address.current_pa[5]);

    printf("Default Hardware Address: %02x-%02x-%02x-%02x-%02x-%02x\n",
        address.default_pa[0], address.default_pa[1], address.default_pa[2],
        address.default_pa[3], address.default_pa[4], address.default_pa[5]);
}
-- 
/--------------------------------------------------------------\
|Jeff Michaud    michaud at decwrl.dec.com  michaud at decvax.dec.com|
|DECnet-ULTRIX   #include <standard/disclaimer.h>              |
\--------------------------------------------------------------/