KlugyTools/CheckResolv/checkresolv.c

/*
 *		CheckResolv
 *		===========
 *
 *	quick and dirty debugging hack.
 *
 */

#include  <stdio.h>
#include  <unistd.h>
#include  <stdlib.h>
#define __USE_BSD
#include  <string.h>
/* #undef __USE_BSD */
#include  <sys/time.h>
#include  <getopt.h>

#define __USE_MISC
#include  <netdb.h>			/* herror ? */

#include  <sys/socket.h>
#include  <netinet/in.h>
#include  <arpa/inet.h>

#include  "fonctions.h"

char * strdup(char *);			/* DIRTY HACK */

/* ------------------------------------------------------------ */
/*	quick and dirty global variables			*/

int	verbose = 0;
int	do_reverse = 0;
int	do_environ = 0;
int	do_timing = 0;	

/* ------------------------------------------------------------ */
/* parameter '*txt' is not used 				*/
int	print_hostent(struct hostent *ph, char *txt)
{
char		*ptr, **pptr;

printf("h_name:       %s\n", ph->h_name);

pptr = ph->h_aliases;
if (verbose) {
	printf("h_aliases:    %p -> %p\n", pptr, *pptr);
	}

while ( (ptr = *(pptr)) != NULL ) {
	printf("   alias:     %s\n", ptr);
	pptr++;
	}

if (verbose) {
	printf("h_addrtype:   %d\n", ph->h_addrtype);
	printf("h_length:     %d\n", ph->h_length);
	}

print_ip((struct in_addr **)ph->h_addr_list);	/* strange cast */

return 0;
}
/* ------------------------------------------------------------ */
/*
 *	If we have a list of IP addr, we can try a 
 *	reverse lookup, no ?
 */
int check_reverse(struct hostent *ph)
{
struct in_addr		**liste;
struct in_addr		*addr;
struct in_addr		l_addr;				/* Jules */
struct hostent		*revph;
int			nbre;
double			t1 , t2;
char			*ptmp;

if (do_timing)	t1 = chronometre();

nbre = 0;
liste = (struct in_addr **)ph->h_addr_list;

while (NULL != (addr = *liste++)) {
	l_addr = *addr;					/* Jules */
#if TRACE
	fprintf(stderr, "---> %p  %p\n", addr, l_addr);
#endif
	revph = gethostbyaddr(&l_addr, ph->h_length, ph->h_addrtype);
	if (NULL != revph) {
		/* taking over hidden string vars  */
		ptmp = strdup(inet_ntoa(l_addr));
		if (NULL == ptmp) {
			fprintf(stderr, "no memory in %s, line %d\n",
							__FILE__, __LINE__);
			abort();
			}
#if TRACE
		fprintf(stderr, "%s:%d %p %p\n", __func__, __LINE__, 
					ptmp, revph->h_name);
#endif
		printf("reverse %-16s -> %s\n", ptmp, revph->h_name); 
		free(ptmp);
		}
	else	{
		/* fprintf(stderr, "reverse ? wtf ?\n"); */
		herror("reverse lookup");	/* this func is obsolete ! */
		}
	nbre++;
	}

if (do_timing) {
	t2 = chronometre();
	if (nbre > 1)
		printf("reverse take %.3f s (%.3f s)\n", t2-t1, (t2-t1)/nbre);
	else
		printf("reverse take %.3f s.\n", t2-t1);
	}

return 0;
}
/* ------------------------------------------------------------ */
struct hostent *direct_lookup(char *hostname)
{
struct hostent	*p_host;
double		t1 , t2;
int		foo;

if (do_timing)	t1 = chronometre();
p_host = gethostbyname(hostname);
if (do_timing)	t2 = chronometre();

if (p_host==NULL)
	{
	fprintf(stderr, "error %d on '%s'", h_errno, hostname);
	herror(" ");
	return NULL;
	}

foo = print_hostent(p_host, NULL);

if (do_timing)	printf("gethostbyname take %.3f s.\n", t2 - t1);

return p_host;
}
/* ------------------------------------------------------------ */
int	analyse(char *nom, int flag)
{
struct hostent	*p_host;

p_host = direct_lookup(nom);

/*
 *  new, 31 jan 2005, v 0.19
 *	if the requested 'hostname' seems to be an ip address, can we 
 *	force a valid reverse lookup ?
 */
if (is_IP_addr(nom) && !do_reverse)
	{
	fprintf(stderr, "* if %s is a valid ip addr, try the '-r' switch.\n",
				nom);
	} 

if (do_reverse && (p_host!=NULL))
	check_reverse(p_host);

return 0;
}
/* ------------------------------------------------------------ */
/*
 *	Set some global flags, based on our environment
 *	variable.
 */
void analyze_environ(void)
{
char	*ptr;

ptr = getenv("CHECKRESOLV");
if (ptr == NULL)
	return;
if ( ! strcmp("tech", ptr) ) {
	do_reverse = 1;
	do_timing = 1;
	}
if ( ! strcmp("all", ptr) ) {
	do_reverse = 1;
	do_timing = 1;
	verbose = 1;
	do_environ = 1;
	}
}
/* ------------------------------------------------------------ */
int main (int argc, char *argv[])
{
int		foo;

char		* liste_opt = "vrhteV";
int		option;

if (argc == 1)		help_options();
	
while ((option=getopt(argc, argv, liste_opt)) != -1)
	{
	switch(option)
		{
		case 'v':	verbose++;		break;
		case 'r':	do_reverse=1;		break;
		case 'e':	do_environ=1;		break;
		case 't':	do_timing=1;		break;
		case 'h':	usage();		break;
		case 'V':	version();		break;
		}
	}

#if TRACE
fprintf(stderr, "argc %d  optind %d\n", argc, optind);
for (foo=optind; foo<argc; foo++)
	{
	fprintf(stderr, "     %4d %s\n", foo, argv[foo]);
	}
#endif

/*
 *	env vars can override command line options.
 */
analyze_environ();

for (foo=optind; foo<argc; foo++)
	{
	printf("------------( %s \n", argv[foo]);
	analyse(argv[foo], 0);
	}

if (do_environ)	print_envvars(0);

return 0;
}
/* ------------------------------------------------------------ */