/*****************************************************************************

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 $Id$
 
*****************************************************************************/

/* Hackers note:
 *  There are typecasts to (char *) from _("foo bar") in this file.
 *  They prevent compiler warnings. Never (ever), permute strings obtained
 *  that are typecast from (const char *) (which happens when --disable-nls)
 *  because on some architectures those strings are in non-writable memory */

const char *progname = "check_dig";
const char *revision = "$Revision$";
const char *copyright = "2002-2004";
const char *email = "nagiosplug-devel@lists.sourceforge.net";

#include "common.h"
#include "netutils.h"
#include "utils.h"
#include "runcmd.h"

int process_arguments (int, char **);
int validate_arguments (void);
void print_help (void);
void print_usage (void);

#define UNDEFINED 0
#define DEFAULT_PORT 53

char *query_address = NULL;
char *record_type = "A";
char *expected_address = NULL;
char *dns_server = NULL;
int verbose = FALSE;
int server_port = DEFAULT_PORT;
double warning_interval = UNDEFINED;
double critical_interval = UNDEFINED;
struct timeval tv;

int
main (int argc, char **argv)
{
	char *command_line;
	output chld_out, chld_err;
	char *msg = NULL;
	size_t i;
	char *t;
	long microsec;
	double elapsed_time;
	int result = STATE_UNKNOWN;

	setlocale (LC_ALL, "");
	bindtextdomain (PACKAGE, LOCALEDIR);
	textdomain (PACKAGE);

	/* Set signal handling and alarm */
	if (signal (SIGALRM, popen_timeout_alarm_handler) == SIG_ERR)
		usage_va(_("Cannot catch SIGALRM"));

	if (process_arguments (argc, argv) == ERROR)
		usage_va(_("Could not parse arguments"));

	/* get the command to run */
	asprintf (&command_line, "%s @%s -p %d %s -t %s",
	          PATH_TO_DIG, dns_server, server_port, query_address, record_type);

	alarm (timeout_interval);
	gettimeofday (&tv, NULL);

	if (verbose) {
		printf ("%s\n", command_line);
		if(expected_address != NULL) {
			printf (_("Looking for: '%s'\n"), expected_address);
		} else {
			printf (_("Looking for: '%s'\n"), query_address);
		}
	}

	/* run the command */
	if(np_runcmd(command_line, &chld_out, &chld_err, 0) != 0) {
		result = STATE_WARNING;
		msg = (char *)_("dig returned an error status");
	}

	for(i = 0; i < chld_out.lines; i++) {
		/* the server is responding, we just got the host name... */
		if (strstr (chld_out.line[i], ";; ANSWER SECTION:")) {

			/* loop through the whole 'ANSWER SECTION' */
			for(; i < chld_out.lines; i++) {
				/* get the host address */
				if (verbose)
					printf ("%s\n", chld_out.line[i]);

				if (strstr (chld_out.line[i], (expected_address == NULL ? query_address : expected_address)) != NULL) {
					msg = chld_out.line[i];
					result = STATE_OK;

					/* Translate output TAB -> SPACE */
					t = msg;
					while ((t = strchr(t, '\t')) != NULL) *t = ' ';
					break;
				}
			}

			if (result == STATE_UNKNOWN) {
				msg = (char *)_("Server not found in ANSWER SECTION");
				result = STATE_WARNING;
			}

			/* we found the answer section, so break out of the loop */
			break;
		}
	}

	if (result == STATE_UNKNOWN)
		msg = (char *)_("No ANSWER SECTION found");

	/* If we get anything on STDERR, at least set warning */
	if(chld_err.buflen > 0) {
		result = max_state(result, STATE_WARNING);
		if(!msg) for(i = 0; i < chld_err.lines; i++) {
			msg = strchr(chld_err.line[0], ':');
			if(msg) {
				msg++;
				break;
			}
		}
	}

	microsec = deltime (tv);
	elapsed_time = (double)microsec / 1.0e6;

	if (critical_interval > UNDEFINED && elapsed_time > critical_interval)
		result = STATE_CRITICAL;

	else if (warning_interval > UNDEFINED && elapsed_time > warning_interval)
		result = STATE_WARNING;

	printf ("DNS %s - %.3f seconds response time (%s)|%s\n",
	        state_text (result), elapsed_time,
	        msg ? msg : _("Probably a non-existent host/domain"),
	        fperfdata("time", elapsed_time, "s",
	                  (warning_interval>UNDEFINED?TRUE:FALSE),
	                  warning_interval,
	                  (critical_interval>UNDEFINED?TRUE:FALSE),
					  critical_interval,
					  TRUE, 0, FALSE, 0));
	return result;
}



/* process command-line arguments */
int
process_arguments (int argc, char **argv)
{
	int c;

	int option = 0;
	static struct option longopts[] = {
		{"hostname", required_argument, 0, 'H'},
		{"query_address", required_argument, 0, 'l'},
		{"warning", required_argument, 0, 'w'},
		{"critical", required_argument, 0, 'c'},
		{"timeout", required_argument, 0, 't'},
		{"verbose", no_argument, 0, 'v'},
		{"version", no_argument, 0, 'V'},
		{"help", no_argument, 0, 'h'},
		{"record_type", required_argument, 0, 'T'},
		{"expected_address", required_argument, 0, 'a'},
		{0, 0, 0, 0}
	};

	if (argc < 2)
		return ERROR;

	while (1) {
		c = getopt_long (argc, argv, "hVvt:l:H:w:c:T:a:", longopts, &option);

		if (c == -1 || c == EOF)
			break;

		switch (c) {
		case 'h':									/* help */
			print_help ();
			exit (STATE_OK);
		case 'V':									/* version */
			print_revision (progname, revision);
			exit (STATE_OK);
		case 'H':									/* hostname */
			host_or_die(optarg);
			dns_server = optarg;
			break;
		case 'p':                 /* server port */
			if (is_intpos (optarg)) {
				server_port = atoi (optarg);
			}
			else {
				usage_va(_("Port must be a positive integer - %s"), optarg);
			}
			break;
		case 'l':									/* address to lookup */
			query_address = optarg;
			break;
		case 'w':									/* warning */
			if (is_nonnegative (optarg)) {
				warning_interval = strtod (optarg, NULL);
			}
			else {
				usage_va(_("Warning interval must be a positive integer - %s"), optarg);
			}
			break;
		case 'c':									/* critical */
			if (is_nonnegative (optarg)) {
				critical_interval = strtod (optarg, NULL);
			}
			else {
				usage_va(_("Critical interval must be a positive integer - %s"), optarg);
			}
			break;
		case 't':									/* timeout */
			if (is_intnonneg (optarg)) {
				timeout_interval = atoi (optarg);
			}
			else {
				usage_va(_("Timeout interval must be a positive integer - %s"), optarg);
			}
			break;
		case 'v':									/* verbose */
			verbose = TRUE;
			break;
		case 'T':
			record_type = optarg;
			break;
		case 'a':
			expected_address = optarg;
			break;
		default:									/* usage_va */
			usage_va(_("Unknown argument - %s"), optarg);
		}
	}

	c = optind;
	if (dns_server == NULL) {
		if (c < argc) {
			host_or_die(argv[c]);
			dns_server = argv[c];
		}
		else {
			dns_server = strdup ("127.0.0.1");
		}
	}

	return validate_arguments ();
}



int
validate_arguments (void)
{
	return OK;
}



void
print_help (void)
{
	char *myport;

	asprintf (&myport, "%d", DEFAULT_PORT);

	print_revision (progname, revision);

	printf ("Copyright (c) 2000 Karl DeBisschop <kdebisschop@users.sourceforge.net>\n");
	printf (COPYRIGHT, copyright, email);

	printf (_("Test the DNS service on the specified host using dig\n\n"));

	print_usage ();

	printf (_(UT_HELP_VRSN));

	printf (_(UT_HOST_PORT), 'P', myport);

	printf (_("\
 -l, --lookup=STRING\n\
   machine name to lookup\n"));

        printf (_("\
 -T, --record_type=STRING\n\
   record type to lookup (default: A)\n"));

        printf (_("\
 -a, --expected_address=STRING\n\
   an address expected to be in the answer section.\n\
   if not set, uses whatever was in -l\n"));

	printf (_(UT_WARN_CRIT));

	printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);

	printf (_(UT_VERBOSE));

	printf (_(UT_SUPPORT));
}



void
print_usage (void)
{
	printf ("\
Usage: %s -H host -l lookup [-p <server port>] [-T <query type>]\n\
              [-w <warning interval>] [-c <critical interval>] [-t <timeout>]\n\
              [-a <expected answer address>] [-v]\n", progname);
}