#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#if defined(sun)
#include <sys/sockio.h>
#else
#include <sys/sysctl.h>
#endif
#include <sys/time.h>
#include <net/if.h>
#include <netinet/in.h>
#if !defined(linux)
#include <netinet/in_var.h>
#endif
#include <netdb.h>
void check_inter (char *, char **);
void usage (char **);
int main (int argc, char **argv)
{
int s;
char *buffer;
struct ifconf ifc;
char name[100];
struct ifreq *ifptr, *end;
struct ifreq ifr;
int ifflags, selectflag = -1;
int oldbufsize, bufsize = sizeof (struct ifreq);
if(!argv[1])
{
usage(argv);
exit(0);
}
printf ("This program should print out valid hosts on all network devices\n");
s = socket (AF_INET, SOCK_DGRAM, 0);
if (s < 0)
{
perror ("ifconfig: socket");
exit (1);
}
buffer = malloc (bufsize);
ifc.ifc_len = bufsize;
do
{
oldbufsize = ifc.ifc_len;
bufsize += 1 + sizeof (struct ifreq);
buffer = realloc ((void *) buffer, bufsize);
ifc.ifc_len = bufsize;
ifc.ifc_buf = buffer;
if (ioctl (s, SIOCGIFCONF, (char *) &ifc) < 0)
{
perror ("ifconfig (SIOCGIFCONF)");
exit (1);
}
}
while (ifc.ifc_len > oldbufsize);
ifflags = ifc.ifc_req->ifr_flags;
end = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
ifptr = ifc.ifc_req;
while (ifptr < end)
{
sprintf (ifr.ifr_name, "%s", ifptr->ifr_name);
sprintf (name, "%s", ifptr->ifr_name);
close (s);
check_inter (name, argv);
ifptr++;
}
return 0;
}
void
check_inter (char *interface, char **argv)
{
struct in_addr i;
struct hostent *he;
struct ifreq ifr;
char rhost[256], fhost[30];
int fd;
char *ip;
register int flags;
ip = malloc (sizeof (ip));
if ((fd = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
return;
strcpy (ifr.ifr_name, interface);
if (ioctl (fd, SIOCGIFADDR, &ifr) < 0)
{
close (fd);
return;
}
if (ioctl (fd, SIOCGIFFLAGS, &ifr) < 0)
{
close (fd);
return;
}
ip = (char *) inet_ntoa (((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr);
if (ifr.ifr_flags & IFF_UP)
{
i.s_addr = inet_addr (ip);
he = gethostbyaddr ((char *) &i, sizeof (struct in_addr), AF_INET);
bzero(rhost, sizeof(rhost));
if (he != NULL)
{
strncpy (rhost, he->h_name, 255);
he = gethostbyname (rhost);
if (he != NULL)
sprintf (fhost, "%u.%u.%u.%u", he->h_addr[0] & 0xff, he->h_addr[1] & 0xff, he->h_addr[2] & 0xff, he->h_addr[3] & 0xff);
}
if (rhost)
{
if (strcasecmp (ip, fhost) == 0)
{
if ((strcmp ("-m", argv[1]) == 0) || (strcmp ("-a", argv[1]) == 0))
{
printf ("Interface %s: %s %s (matching)\n", interface, ip, rhost);
bzero (rhost, sizeof (rhost));
bzero (fhost, sizeof (fhost));
}
}
else if ((strcmp("-r", argv[1])==0) || (strcmp("-a", argv[1]) == 0))
{
printf ("Interface %s: %s %s\n", interface, ip, rhost);
bzero (rhost, sizeof (rhost));
}
}
else if ((strcmp("-i", argv[1]) ==0) || (strcmp("-a", argv[1]) == 0))
printf ("Interface %s: %s\n", interface, ip);
}
close (fd);
}
void usage(char **argv)
{
printf("\nVirtual Host checking system by Warren Rees\n");
printf("Support for reverse dns and dns matching by Matt Watson\n\n");
printf("Usage: %s [-amri]\n\n", argv[0]);
printf("\t-a : Show all ips\n");
printf("\t-m : Show only ips & hostname with matching forward and reverse dns\n");
printf("\t-r : Show only ips that have reverse dns but no forward dns\n");
printf("\t-i : Show only non-resolving ips no forward or reverse dns\n\n\n");
}
