/******************************************************************************
 *
 * Program: MRTG (Multi-Router Traffic Grapher) generic plugin for Nagios
 * License: GPL
 *
 * License Information:
 *
 * 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.
 *
 * $Id$
 *
 *****************************************************************************/

const char *progname = "check_mrtg";
#define REVISION "$Revision$"
#define COPYRIGHT "Copyright (c) 1999-2001 Ethan Galstad"

#define SUMMARY "\
This plugin will check either the average or maximum value of one of the\n\
two variables recorded in an MRTG log file.\n"

/* old command line: 
	 <log_file> <expire_minutes> <AVG|MAX> <variable> <vwl> <vcl> <label> [units] */
#define OPTIONS "\
-F log_file -a <AVG | MAX> -v variable -w warning -c critical\n\
            [-l label] [-u units] [-e expire_minutes] [-t timeout] [-v]"

#define LONGOPTIONS "\
 -F, --logfile=FILE\n\
   The MRTG log file containing the data you want to monitor\n\
 -e, --expires=MINUTES\n\
   Minutes before MRTG data is considered to be too old\n\
 -a, --aggregation=AVG|MAX\n\
   Should we check average or maximum values?\n\
 -v, --variable=INTEGER\n\
   Which variable set should we inspect? 1 or 2?\n\
 -w, --warning=INTEGER\n\
   Threshold value for data to result in WARNING status\n\
 -c, --critical=INTEGER\n\
   Threshold value for data to result in CRITICAL status\n\
 -l, --label=STRING\n\
   Type label for data (Examples: Conns, \"Processor Load\", In, Out)\n\
 -u, --units=STRING\n\
   Option units label for data (Example: Packets/Sec, Errors/Sec, \n\
   \"Bytes Per Second\", \"%% Utilization\")\n\
 -h, --help\n\
   Print detailed help screen\n\
 -V, --version\n\
   Print version information\n"

#define DESCRIPTION "\
If the value exceeds the <vwl> threshold, a WARNING status is returned.  If\n\
the value exceeds the <vcl> threshold, a CRITICAL status is returned.  If\n\
the data in the log file is older than <expire_minutes> old, a WARNING\n\
status is returned and a warning message is printed.\n\
\n\
This plugin is useful for monitoring MRTG data that does not correspond to\n\
bandwidth usage.  (Use the check_mrtgtraf plugin for monitoring bandwidth).\n\
It can be used to monitor any kind of data that MRTG is monitoring - errors,\n\
packets/sec, etc.  I use MRTG in conjuction with the Novell NLM that allows\n\
me to track processor utilization, user connections, drive space, etc and\n\
this plugin works well for monitoring that kind of data as well.\n\
\n\
Notes:\n\
- This plugin only monitors one of the two variables stored in the MRTG log\n\
  file.  If you want to monitor both values you will have to define two\n\
  commands with different values for the <variable> argument.  Of course,\n\
  you can always hack the code to make this plugin work for you...\n\
- MRTG stands for the Multi Router Traffic Grapher.  It can be downloaded from\n\
  http://ee-staff.ethz.ch/~oetiker/webtools/mrtg/mrtg.html\n"

#include "config.h"
#include "common.h"
#include "utils.h"

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

char *log_file = NULL;
int expire_minutes = 0;
int use_average = TRUE;
int variable_number = -1;
unsigned long value_warning_threshold = 0L;
unsigned long value_critical_threshold = 0L;
char *value_label = "";
char *units_label = "";

int
main (int argc, char **argv)
{
	int result = STATE_OK;
	FILE *fp;
	int line;
	char input_buffer[MAX_INPUT_BUFFER];
	char *temp_buffer;
	time_t current_time;
	char error_message[MAX_INPUT_BUFFER];
	time_t timestamp = 0L;
	unsigned long average_value_rate = 0L;
	unsigned long maximum_value_rate = 0L;
	unsigned long value_rate = 0L;

	if (process_arguments (argc, argv) != OK)
		usage ("Invalid command arguments supplied\n");

	/* open the MRTG log file for reading */
	fp = fopen (log_file, "r");
	if (fp == NULL) {
		printf ("Unable to open MRTG log file\n");
		return STATE_UNKNOWN;
	}

	line = 0;
	while (fgets (input_buffer, MAX_INPUT_BUFFER - 1, fp)) {

		line++;

		/* skip the first line of the log file */
		if (line == 1)
			continue;

		/* break out of read loop if we've passed the number of entries we want to read */
		if (line > 2)
			break;

		/* grab the timestamp */
		temp_buffer = strtok (input_buffer, " ");
		timestamp = strtoul (temp_buffer, NULL, 10);

		/* grab the average value 1 rate */
		temp_buffer = strtok (NULL, " ");
		if (variable_number == 1)
			average_value_rate = strtoul (temp_buffer, NULL, 10);

		/* grab the average value 2 rate */
		temp_buffer = strtok (NULL, " ");
		if (variable_number == 2)
			average_value_rate = strtoul (temp_buffer, NULL, 10);

		/* grab the maximum value 1 rate */
		temp_buffer = strtok (NULL, " ");
		if (variable_number == 1)
			maximum_value_rate = strtoul (temp_buffer, NULL, 10);

		/* grab the maximum value 2 rate */
		temp_buffer = strtok (NULL, " ");
		if (variable_number == 2)
			maximum_value_rate = strtoul (temp_buffer, NULL, 10);
	}

	/* close the log file */
	fclose (fp);

	/* if we couldn't read enough data, return an unknown error */
	if (line <= 2) {
		result = STATE_UNKNOWN;
		sprintf (error_message, "Unable to process MRTG log file\n");
	}

	/* make sure the MRTG data isn't too old */
	if (result == STATE_OK) {
		time (&current_time);
		if (expire_minutes > 0
				&& (current_time - timestamp) > (expire_minutes * 60)) {
			result = STATE_WARNING;
			sprintf (error_message, "MRTG data has expired (%d minutes old)\n",
							 (int) ((current_time - timestamp) / 60));
		}
	}

	/* else check the incoming/outgoing rates */
	if (result == STATE_OK) {

		if (use_average == TRUE)
			value_rate = average_value_rate;
		else
			value_rate = maximum_value_rate;

		if (value_rate > value_critical_threshold)
			result = STATE_CRITICAL;
		else if (value_rate > value_warning_threshold)
			result = STATE_WARNING;
	}

	sprintf (error_message, "%s. %s = %lu %s",
					 (use_average == TRUE) ? "Ave" : "Max", value_label, value_rate,
					 units_label);
	printf ("%s\n", error_message);

	return result;
}





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

#ifdef HAVE_GETOPT_H
	int option_index = 0;
	static struct option long_options[] = {
		{"logfile", required_argument, 0, 'F'},
		{"expires", required_argument, 0, 'e'},
		{"aggregation", required_argument, 0, 'a'},
		{"variable", required_argument, 0, 'v'},
		{"critical", required_argument, 0, 'c'},
		{"warning", required_argument, 0, 'w'},
		{"label", required_argument, 0, 'l'},
		{"units", required_argument, 0, 'u'},
		{"verbose", no_argument, 0, 'v'},
		{"version", no_argument, 0, 'V'},
		{"help", no_argument, 0, 'h'},
		{0, 0, 0, 0}
	};
#endif

	if (argc < 2)
		return ERROR;

	for (c = 1; c < argc; c++) {
		if (strcmp ("-to", argv[c]) == 0)
			strcpy (argv[c], "-t");
		else if (strcmp ("-wt", argv[c]) == 0)
			strcpy (argv[c], "-w");
		else if (strcmp ("-ct", argv[c]) == 0)
			strcpy (argv[c], "-c");
	}

	while (1) {
#ifdef HAVE_GETOPT_H
		c =
			getopt_long (argc, argv, "hVF:e:a:v:c:w:l:u:", long_options,
									 &option_index);
#else
		c = getopt (argc, argv, "hVF:e:a:v:c:w:l:u:");
#endif

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

		switch (c) {
		case 'F':									/* input file */
			log_file = optarg;
			break;
		case 'e':									/* ups name */
			expire_minutes = atoi (optarg);
			break;
		case 'a':									/* port */
			if (!strcmp (optarg, "MAX"))
				use_average = FALSE;
			else
				use_average = TRUE;
			break;
		case 'v':
			variable_number = atoi (optarg);
			if (variable_number < 1 || variable_number > 2)
				usage ("Invalid variable number\n");
			break;
		case 'w':									/* critical time threshold */
			value_warning_threshold = strtoul (optarg, NULL, 10);
			break;
		case 'c':									/* warning time threshold */
			value_critical_threshold = strtoul (optarg, NULL, 10);
			break;
		case 'l':									/* label */
			value_label = optarg;
			break;
		case 'u':									/* timeout */
			units_label = optarg;
			break;
		case 'V':									/* version */
			print_revision (progname, REVISION);
			exit (STATE_OK);
		case 'h':									/* help */
			print_help ();
			exit (STATE_OK);
		case '?':									/* help */
			usage ("Invalid argument\n");
		}
	}

	c = optind;
	if (log_file == NULL && argc > c) {
		log_file = argv[c++];
	}

	if (expire_minutes <= 0 && argc > c) {
		if (is_intpos (argv[c]))
			expire_minutes = atoi (argv[c++]);
		else
			terminate (STATE_UNKNOWN,
			           "%s is not a valid expiration time\nUse '%s -h' for additional help\n",
			           argv[c], progname);
	}

	if (argc > c && strcmp (argv[c], "MAX") == 0) {
		use_average = FALSE;
		c++;
	}
	else if (argc > c && strcmp (argv[c], "AVG") == 0) {
		use_average = TRUE;
		c++;
	}

	if (argc > c && variable_number == -1) {
		variable_number = atoi (argv[c++]);
		if (variable_number < 1 || variable_number > 2) {
			printf ("%s :", argv[c]);
			usage ("Invalid variable number\n");
		}
	}

	if (argc > c && value_warning_threshold == 0) {
		value_warning_threshold = strtoul (argv[c++], NULL, 10);
	}

	if (argc > c && value_critical_threshold == 0) {
		value_critical_threshold = strtoul (argv[c++], NULL, 10);
	}

	if (argc > c && strlen (value_label) == 0) {
		value_label = argv[c++];
	}

	if (argc > c && strlen (units_label) == 0) {
		units_label = argv[c++];
	}

	return validate_arguments ();
}

int
validate_arguments (void)
{
	if (variable_number == -1)
		usage ("You must supply the variable number\n");

	return OK;
}

void
print_help (void)
{
	print_revision (progname, REVISION);
	printf ("%s\n\n%s\n", COPYRIGHT, SUMMARY);
	print_usage ();
	printf ("\nOptions:\n" LONGOPTIONS "\n" DESCRIPTION "\n");
	support ();
}

void
print_usage (void)
{
	printf ("Usage:\n" " %s %s\n"
#ifdef HAVE_GETOPT_H
					" %s (-h | --help) for detailed help\n"
					" %s (-V | --version) for version information\n",
#else
					" %s -h for detailed help\n"
					" %s -V for version information\n",
#endif
					progname, OPTIONS, progname, progname);
}