pcap_findalldevs on RH9 return invalid eth0 IP address about libpcap HOT 3 CLOSED

/*
 * x was here
 * cc iip.c -lpcap -o iip
 */

#define _GNU_SOURCE     /* needed by vasprintf */
#define __USE_BSD

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <pcap.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>



char            errbuf[PCAP_ERRBUF_SIZE];


char           *ipfromlong(unsigned long s_addr);
u_int32_t       get_interface_addr(char *interface);
void            fatal(char *pattern, ...);


int
main(int argc, char **argv)
{
    if (argc != 2) {
    printf("usage: %s interface\n\n", argv[0]);
    exit(0);
    }

    printf("device: %s address: %s\n", argv[1],
       ipfromlong(get_interface_addr(argv[1])));

    return 0;
}



void
fatal(char *pattern, ...)
{
    va_list         ap;
    int             len;
    char           *p;

    va_start(ap, pattern);
    len = vasprintf(&p, pattern, ap);
    va_end(ap);

    if (len > 0) {
        printf("%s; exit forced.\n", p);
        free(p);
    }

    exit(1);
}


char
               *
ipfromlong(unsigned long s_addr)
{
    struct in_addr  myaddr;

    myaddr.s_addr = s_addr;
    return inet_ntoa(myaddr);
}


u_int32_t
get_interface_addr(char *interface)
{
    pcap_if_t      *dev,
                   *alldevs;
    u_int32_t       ret;
    struct pcap_addr *addr;

    if (strcmp("lo", interface) == 0)
    return (htonl(INADDR_LOOPBACK));

    if (pcap_findalldevs(&alldevs, errbuf) < 0)
    fatal("pcap_findalldevs(): %s", errbuf);

    ret = INADDR_NONE;

    for (dev = alldevs; dev; dev = dev->next) {
    if (strcmp(dev->name, interface) == 0) {
        for (addr = dev->addresses; addr; addr = addr->next) {
        if (addr->addr && addr->addr->sa_family == AF_INET) {
            ret =
            ((struct sockaddr_in *) (addr->addr))->sin_addr.s_addr;
            break;
        }
        }
    }
    }

    pcap_freealldevs(alldevs);

    if (ret == INADDR_NONE)
    fatal("get_interface_addr(): address not found");

    return ret;
}