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

 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_pgsql";
const char *revision = "$Revision$";
const char *copyright = "1999-2004";
const char *email = "nagiosplug-devel@lists.sourceforge.net";

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

#include "netutils.h"
#include <libpq-fe.h>

#define DEFAULT_DB "template1"
#define DEFAULT_HOST "127.0.0.1"

enum {
	DEFAULT_PORT = 5432,
	DEFAULT_WARN = 2,
	DEFAULT_CRIT = 8
};



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

char *pghost = NULL;						/* host name of the backend server */
char *pgport = NULL;						/* port of the backend server */
int default_port = DEFAULT_PORT;
char *pgoptions = NULL;
char *pgtty = NULL;
char dbName[NAMEDATALEN] = DEFAULT_DB;
char *pguser = NULL;
char *pgpasswd = NULL;
double twarn = (double)DEFAULT_WARN;
double tcrit = (double)DEFAULT_CRIT;

PGconn *conn;
/*PGresult   *res;*/


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

The (psuedo?)literate programming XML is contained within \@\@\- <XML> \-\@\@
tags in the comments. With in the tags, the XML is assembled sequentially.
You can define entities in tags. You also have all the #defines available as
entities.

Please note that all tags must be lowercase to use the DocBook XML DTD.

@@-<article>

<sect1>
<title>Quick Reference</title>
<!-- The refentry forms a manpage -->
<refentry>
<refmeta>
<manvolnum>5<manvolnum>
</refmeta>
<refnamdiv>
<refname>&progname;</refname>
<refpurpose>&SUMMARY;</refpurpose>
</refnamdiv>
</refentry>
</sect1>

<sect1>
<title>FAQ</title>
</sect1>

<sect1>
<title>Theory, Installation, and Operation</title>

<sect2>
<title>General Description</title>
<para>
&DESCRIPTION;
</para>
</sect2>

<sect2>
<title>Future Enhancements</title>
<para>ToDo List</para>
<itemizedlist>
<listitem>Add option to get password from a secured file rather than the command line</listitem>
<listitem>Add option to specify the query to execute</listitem>
</itemizedlist>
</sect2>


<sect2>
<title>Functions</title>
-@@
******************************************************************************/



int
main (int argc, char **argv)
{
	int elapsed_time;
	int status = STATE_UNKNOWN;

	/* begin, by setting the parameters for a backend connection if the
	 * parameters are null, then the system will try to use reasonable
	 * defaults by looking up environment variables or, failing that,
	 * using hardwired constants */

	pgoptions = NULL;  /* special options to start up the backend server */
	pgtty = NULL;      /* debugging tty for the backend server */

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

	if (process_arguments (argc, argv) != TRUE)
		usage4 (_("Could not parse arguments"));

	/* Set signal handling and alarm */
	if (signal (SIGALRM, timeout_alarm_handler) == SIG_ERR) {
		usage4 (_("Cannot catch SIGALRM"));
	}
	alarm (timeout_interval);

	/* make a connection to the database */
	time (&start_time);
	conn =
		PQsetdbLogin (pghost, pgport, pgoptions, pgtty, dbName, pguser, pgpasswd);
	time (&end_time);
	elapsed_time = (int) (end_time - start_time);

	/* check to see that the backend connection was successfully made */
	if (PQstatus (conn) == CONNECTION_BAD) {
		printf (_("CRITICAL - no connection to '%s' (%s).\n"),
		        dbName,	PQerrorMessage (conn));
		PQfinish (conn);
		return STATE_CRITICAL;
	}
	else if (elapsed_time > tcrit) {
		status = STATE_CRITICAL;
	}
	else if (elapsed_time > twarn) {
		status = STATE_WARNING;
	}
	else {
		status = STATE_OK;
	}
	PQfinish (conn);
	printf (_(" %s - database %s (%d sec.)|%s\n"), 
	        state_text(status), dbName, elapsed_time,
	        fperfdata("time", elapsed_time, "s",
	                 (int)twarn, twarn, (int)tcrit, tcrit, TRUE, 0, FALSE,0));
	return status;
}



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

	int option = 0;
	static struct option longopts[] = {
		{"help", no_argument, 0, 'h'},
		{"version", no_argument, 0, 'V'},
		{"timeout", required_argument, 0, 't'},
		{"critical", required_argument, 0, 'c'},
		{"warning", required_argument, 0, 'w'},
		{"hostname", required_argument, 0, 'H'},
		{"logname", required_argument, 0, 'l'},
		{"password", required_argument, 0, 'p'},
		{"authorization", required_argument, 0, 'a'},
		{"port", required_argument, 0, 'P'},
		{"database", required_argument, 0, 'd'},
		{0, 0, 0, 0}
	};

	while (1) {
		c = getopt_long (argc, argv, "hVt:c:w:H:P:d:l:p:a:",
		                 longopts, &option);

		if (c == EOF)
			break;

		switch (c) {
		case '?':     /* usage */
			printf (_("%s: Unknown argument: %s\n\n"), progname, optarg);
			print_usage ();
			exit (STATE_UNKNOWN);
		case 'h':     /* help */
			print_help ();
			exit (STATE_OK);
		case 'V':     /* version */
			print_revision (progname, revision);
			exit (STATE_OK);
		case 't':     /* timeout period */
			if (!is_integer (optarg))
				usage2 (_("Timeout interval must be a positive integer"), optarg);
			else
				timeout_interval = atoi (optarg);
			break;
		case 'c':     /* critical time threshold */
			if (!is_nonnegative (optarg))
				usage2 (_("Critical threshold must be a positive integer"), optarg);
			else
				tcrit = strtod (optarg, NULL);
			break;
		case 'w':     /* warning time threshold */
			if (!is_nonnegative (optarg))
				usage2 (_("Critical threshold must be a positive integer"), optarg);
			else
				twarn = strtod (optarg, NULL);
			break;
		case 'H':     /* host */
			if (!is_host (optarg))
				usage2 (_("Invalid hostname/address"), optarg);
			else
				pghost = optarg;
			break;
		case 'P':     /* port */
			if (!is_integer (optarg))
				usage2 (_("Port must be a positive integer"), optarg);
			else
				pgport = optarg;
			break;
		case 'd':     /* database name */
			if (!is_pg_dbname (optarg)) /* checks length and valid chars */
				usage2 (_("Database name is not valid"), optarg);
			else /* we know length, and know optarg is terminated, so us strcpy */
				strcpy (dbName, optarg);
			break;
		case 'l':     /* login name */
			if (!is_pg_logname (optarg))
				usage2 (_("user name is not valid"), optarg);
			else
				pguser = optarg;
			break;
		case 'p':     /* authentication password */
		case 'a':
			pgpasswd = optarg;
			break;
		}
	}

	return validate_arguments ();
}


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

@@-
<sect3>
<title>validate_arguments</title>

<para>&PROTO_validate_arguments;</para>

<para>Given a database name, this function returns TRUE if the string
is a valid PostgreSQL database name, and returns false if it is
not.</para>

<para>Valid PostgreSQL database names are less than &NAMEDATALEN;
characters long and consist of letters, numbers, and underscores. The
first character cannot be a number, however.</para>

</sect3>
-@@
******************************************************************************/



int
validate_arguments ()
{
	return OK;
}


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

@@-
<sect3>
<title>is_pg_dbname</title>

<para>&PROTO_is_pg_dbname;</para>

<para>Given a database name, this function returns TRUE if the string
is a valid PostgreSQL database name, and returns false if it is
not.</para>

<para>Valid PostgreSQL database names are less than &NAMEDATALEN;
characters long and consist of letters, numbers, and underscores. The
first character cannot be a number, however.</para>

</sect3>
-@@
******************************************************************************/



int
is_pg_dbname (char *dbname)
{
	char txt[NAMEDATALEN];
	char tmp[NAMEDATALEN];
	if (strlen (dbname) > NAMEDATALEN - 1)
		return (FALSE);
	strncpy (txt, dbname, NAMEDATALEN - 1);
	txt[NAMEDATALEN - 1] = 0;
	if (sscanf (txt, "%[_a-zA-Z]%[^_a-zA-Z0-9]", tmp, tmp) == 1)
		return (TRUE);
	if (sscanf (txt, "%[_a-zA-Z]%[_a-zA-Z0-9]%[^_a-zA-Z0-9]", tmp, tmp, tmp) ==
			2) return (TRUE);
	return (FALSE);
}

/**

the tango program should eventually create an entity here based on the 
function prototype

@@-
<sect3>
<title>is_pg_logname</title>

<para>&PROTO_is_pg_logname;</para>

<para>Given a username, this function returns TRUE if the string is a
valid PostgreSQL username, and returns false if it is not. Valid PostgreSQL
usernames are less than &NAMEDATALEN; characters long and consist of
letters, numbers, dashes, and underscores, plus possibly some other
characters.</para>

<para>Currently this function only checks string length. Additional checks
should be added.</para>

</sect3>
-@@
******************************************************************************/



int
is_pg_logname (char *username)
{
	if (strlen (username) > NAMEDATALEN - 1)
		return (FALSE);
	return (TRUE);
}

/******************************************************************************
@@-
</sect2> 
</sect1>
</article>
-@@
******************************************************************************/



void
print_help (void)
{
	char *myport;

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

	print_revision (progname, revision);

	printf (_(COPYRIGHT), copyright, email);

	printf (_("Test whether a PostgreSQL Database is accepting connections.\n\n"));

	print_usage ();

	printf (_(UT_HELP_VRSN));

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

	printf (_(UT_IPv46));

	printf (S_("\
  -d, --database=STRING\n\
    Database to check (default: %s)\n\
  -l, --logname = STRING\n\
    Login name of user\n\
  -p, --password = STRING\n\
    Password (BIG SECURITY ISSUE)\n"), DEFAULT_DB);

	printf (_(UT_WARN_CRIT));

	printf (_(UT_TIMEOUT), DEFAULT_SOCKET_TIMEOUT);

	printf (_(UT_VERBOSE));

	printf (S_("\nAll parameters are optional.\n\
\n\
This plugin tests a PostgreSQL DBMS to determine whether it is active and\n\
accepting queries. In its current operation, it simply connects to the\n\
specified database, and then disconnects. If no database is specified, it\n\
connects to the template1 database, which is present in every functioning \n\
PostgreSQL DBMS.\n"));
	printf (S_("\n\
The plugin will connect to a local postmaster if no host is specified. To\n\
connect to a remote host, be sure that the remote postmaster accepts TCP/IP\n\
connections (start the postmaster with the -i option).\n"));
	printf (S_("\n\
Typically, the nagios user (unless the --logname option is used) should be\n\
able to connect to the database without a password. The plugin can also send\n\
a password, but no effort is made to obsure or encrypt the password.\n"));

	printf (_(UT_SUPPORT));
}



void
print_usage (void)
{
	printf (S_("\
Usage:\n %s [-H <host>] [-P <port>] [-c <critical time>] [-w <warning time>]\n\
            [-t <timeout>]"), progname);
	printf (S_("[-d <database>] [-l <logname>] [-p <password>]\n"));
	printf (S_("\
         %s (-h | --help) for detailed help\n\
         %s (-V | --version) for version information\n"),
					progname, progname);
}