nagios-plugins/plugins/check_by_ssh.c

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

 The Nagios Plugins are free software; you can redistribute them
 and/or modify them 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_by_ssh";
const char *revision = "$Revision$";
const char *copyright = "2000-2004";
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);

int commands = 0;
int services = 0;
int skip = 0;
char *remotecmd = NULL;
char *comm = NULL;
char *hostname = NULL;
char *outputfile = NULL;
char *host_shortname = NULL;
char **service;
int passive = FALSE;
int verbose = FALSE;

int
main (int argc, char **argv)
{

	char *status_text;
	int cresult;
	int result = STATE_UNKNOWN;
	int i;
	time_t local_time;
	FILE *fp = NULL;
	struct output chld_out, chld_err;

	remotecmd = "";
	comm = strdup (SSH_COMMAND);

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

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

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

	/* run the command */
	if (verbose)
		printf ("%s\n", comm);

	result = np_runcmd(comm, &chld_out, &chld_err, 0);
	/* UNKNOWN if output found on stderr */
	if(chld_err.buflen) {
		printf(_("Remote command execution failed: %s\n"),
			   chld_err.buflen ? chld_err.buf : _("Unknown error"));
		return STATE_UNKNOWN;
	}

	/* this is simple if we're not supposed to be passive.
	 * Wrap up quickly and keep the tricks below */
	if(!passive) {
		printf ("%s\n", skip < chld_out.lines ? chld_out.line[skip] : chld_out.buf);
		return result; 	/* return error status from remote command */
	}


	/*
	 * Passive mode
	 */

	/* process output */
	if (!(fp = fopen (outputfile, "a"))) {
		printf (_("SSH WARNING: could not open %s\n"), outputfile);
		exit (STATE_UNKNOWN);
	}

	local_time = time (NULL);
	commands = 0;
	for(i = skip; chld_out.line[i]; i++) {
		status_text = strstr (chld_out.line[i], "STATUS CODE: ");
		if (status_text == NULL) {
			printf ("%s", chld_out.line[i]);
			return result;
		}
		if (service[commands] && status_text
			&& sscanf (status_text, "STATUS CODE: %d", &cresult) == 1)
		{
			fprintf (fp, "[%d] PROCESS_SERVICE_CHECK_RESULT;%s;%s;%d;%s\n",
			         (int) local_time, host_shortname, service[commands++],
			         cresult, chld_out.line[i]);
		}
	}
	
	/* force an OK state */
	return result;
}

/* process command-line arguments */
int
process_arguments (int argc, char **argv)
{
	int c;
	char *p1, *p2;

	int option = 0;
	static struct option longopts[] = {
		{"version", no_argument, 0, 'V'},
		{"help", no_argument, 0, 'h'},
		{"verbose", no_argument, 0, 'v'},
		{"fork", no_argument, 0, 'f'},
		{"timeout", required_argument, 0, 't'},
		{"host", required_argument, 0, 'H'},
		{"port", required_argument,0,'p'},
		{"output", required_argument, 0, 'O'},
		{"name", required_argument, 0, 'n'},
		{"services", required_argument, 0, 's'},
		{"identity", required_argument, 0, 'i'},
		{"user", required_argument, 0, 'u'},
		{"logname", required_argument, 0, 'l'},
		{"command", required_argument, 0, 'C'},
		{"skip", required_argument, 0, 'S'},
		{"proto1", no_argument, 0, '1'},
		{"proto2", no_argument, 0, '2'},
		{"use-ipv4", no_argument, 0, '4'},
		{"use-ipv6", no_argument, 0, '6'},
		{0, 0, 0, 0}
	};

	if (argc < 2)
		return ERROR;

	for (c = 1; c < argc; c++)
		if (strcmp ("-to", argv[c]) == 0)
			strcpy (argv[c], "-t");

	while (1) {
		c = getopt_long (argc, argv, "Vvh1246ft:H:O:p:i:u:l:C:S:n:s:", longopts,
		                 &option);

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

		switch (c) {
		case 'V':									/* version */
			print_revision (progname, revision);
			exit (STATE_OK);
		case 'h':									/* help */
			print_help ();
			exit (STATE_OK);
		case 'v':									/* help */
			verbose = TRUE;
			break;
		case 't':									/* timeout period */
			if (!is_integer (optarg))
				usage_va(_("Timeout interval must be a positive integer"));
			else
				timeout_interval = atoi (optarg);
			break;
		case 'H':									/* host */
			host_or_die(optarg);
			hostname = optarg;
			break;
		case 'p': /* port number */
			if (!is_integer (optarg))
				usage_va(_("Port must be a positive integer"));
			asprintf (&comm,"%s -p %s", comm, optarg);
			break;
		case 'O':									/* output file */
			outputfile = optarg;
			passive = TRUE;
			break;
		case 's':									/* description of service to check */
			p1 = optarg;
			service = realloc (service, (++services) * sizeof(char *));
			while ((p2 = index (p1, ':'))) {
				*p2 = '\0';
				service[services - 1] = p1;
				service = realloc (service, (++services) * sizeof(char *));
				p1 = p2 + 1;
			}
			service[services - 1] = p1;
			break;
		case 'n':									/* short name of host in nagios configuration */
			host_shortname = optarg;
			break;

		case 'u':
			c = 'l';
		case 'l':									/* login name */
		case 'i':									/* identity */
			asprintf (&comm, "%s -%c %s", comm, c, optarg);
			break;

		case '1':									/* Pass these switches directly to ssh */
		case '2':									/* 1 to force version 1, 2 to force version 2 */
		case '4':									/* -4 for IPv4 */
		case '6': 								/* -6 for IPv6 */
		case 'f':									/* fork to background */
			asprintf (&comm, "%s -%c", comm, c);
			break;
		case 'C':									/* Command for remote machine */
			commands++;
			if (commands > 1)
				asprintf (&remotecmd, "%s;echo STATUS CODE: $?;", remotecmd);
			asprintf (&remotecmd, "%s%s", remotecmd, optarg);
			break;
		case 'S':									/* Skip n lines in the output to ignore system banner */
			if (!is_integer (optarg))
				usage_va(_("skip lines must be an integer"));
			else
				skip = atoi (optarg);
			break;
		default:									/* help */
			usage_va(_("Unknown argument - %s"), optarg);
		}
	}

	c = optind;
	if (hostname == NULL) {
		if (c <= argc) {
			die (STATE_UNKNOWN, _("%s: You must provide a host name\n"), progname);
		}
		host_or_die(argv[c]);
		hostname = argv[c++];
	}

	if (strlen(remotecmd) == 0) {
		for (; c < argc; c++)
			if (strlen(remotecmd) > 0)
				asprintf (&remotecmd, "%s %s", remotecmd, argv[c]);
			else
				asprintf (&remotecmd, "%s", argv[c]);
	}

	if (commands > 1)
		asprintf (&remotecmd, "%s;echo STATUS CODE: $?;", remotecmd);

	if (remotecmd == NULL || strlen (remotecmd) <= 1)
		usage_va(_("No remotecmd"));

	asprintf (&comm, "%s %s '%s'", comm, hostname, remotecmd);

	return validate_arguments ();
}



int
validate_arguments (void)
{
	if (remotecmd == NULL || hostname == NULL)
		return ERROR;

	if (passive && commands != services)
		die (STATE_UNKNOWN, _("%s: In passive mode, you must provide a service name for each command.\n"), progname);

	if (passive && host_shortname == NULL)
		die (STATE_UNKNOWN, _("%s: In passive mode, you must provide the host short name from the nagios configs.\n"), progname);

	return OK;
}


void
print_help (void)
{
	print_revision (progname, revision);

	printf ("Copyright (c) 1999 Karl DeBisschop <kdebisschop@users.sourceforge.net>\n");
	printf (COPYRIGHT, copyright, email);

	printf (_("This plugin uses SSH to execute commands on a remote host\n\n"));

	print_usage ();

	printf (_(UT_HELP_VRSN));

	printf (_(UT_HOST_PORT), 'p', "none");

	printf (_(UT_IPv46));

	printf (_("\
 -1, --proto1\n\
    tell ssh to use Protocol 1\n\
 -2, --proto2\n\
    tell ssh to use Protocol 2\n\
 -S, --skiplines=n\n\
    Ignore first n lines on STDERR (to suppress a logon banner)\n\
 -f\n\
    tells ssh to fork rather than create a tty\n"));

	printf (_("\
 -C, --command='COMMAND STRING'\n\
    command to execute on the remote machine\n\
 -l, --logname=USERNAME\n\
    SSH user name on remote host [optional]\n\
 -i, --identity=KEYFILE\n\
    identity of an authorized key [optional]\n\
 -O, --output=FILE\n\
    external command file for nagios [optional]\n\
 -s, --services=LIST\n\
    list of nagios service names, separated by ':' [optional]\n\
 -n, --name=NAME\n\
    short name of host in nagios configuration [optional]\n"));

	printf (_(UT_WARN_CRIT));

	printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);

	printf (_("\n\
The most common mode of use is to refer to a local identity file with\n\
the '-i' option. In this mode, the identity pair should have a null\n\
passphrase and the public key should be listed in the authorized_keys\n\
file of the remote host. Usually the key will be restricted to running\n\
only one command on the remote server. If the remote SSH server tracks\n\
invocation arguments, the one remote program may be an agent that can\n\
execute additional commands as proxy\n"));

	printf (_("\n\
To use passive mode, provide multiple '-C' options, and provide\n\
all of -O, -s, and -n options (servicelist order must match '-C'\n\
options)\n"));

	printf ("\n\
$ check_by_ssh -H localhost -n lh -s c1:c2:c3 \\\n\
    -C uptime -C uptime -C uptime -O /tmp/foo\n\
$ cat /tmp/foo\n\
[1080933700] PROCESS_SERVICE_CHECK_RESULT;flint;c1;0; up 2 days...\n\
[1080933700] PROCESS_SERVICE_CHECK_RESULT;flint;c2;0; up 2 days...\n\
[1080933700] PROCESS_SERVICE_CHECK_RESULT;flint;c3;0; up 2 days...\n");

	printf (_(UT_SUPPORT));
}



void
print_usage (void)
{
	printf ("\n\
Usage: %s [-f46] [-t timeout] [-i identity] [-l user] -H <host> -C <command>\n\
                  [-n name] [-s servicelist] [-O outputfile] [-p port]\n", progname);
}