Merge remote-tracking branch 'github/tokkee/sh/check_dbi'

1 files changed, 817 insertions, 0 deletions

diff --git a/plugins/check_dbi.c b/plugins/check_dbi.c
new file mode 100644
index 00000000..8c4a511d
--- /dev/null
+++ b/plugins/check_dbi.c
@@ -0,0 +1,817 @@
+/*****************************************************************************
+* 
+* Nagios check_dbi plugin
+* 
+* License: GPL
+* Copyright (c) 2011 Nagios Plugins Development Team
+* Author: Sebastian 'tokkee' Harl <sh@teamix.net>
+* 
+* Description:
+* 
+* This file contains the check_dbi plugin
+* 
+* Runs an arbitrary (SQL) command and checks the result.
+* 
+* 
+* 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 3 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, see <http://www.gnu.org/licenses/>.
+* 
+* 
+*****************************************************************************/
+
+const char *progname = "check_dbi";
+const char *copyright = "2011";
+const char *email = "nagiosplug-devel@lists.sourceforge.net";
+
+#include "common.h"
+#include "utils.h"
+
+#include "netutils.h"
+
+#include "regex.h"
+
+/* required for NAN */
+#ifndef _ISOC99_SOURCE
+#define _ISOC99_SOURCE
+#endif
+
+#include <assert.h>
+#include <math.h>
+
+#include <dbi/dbi.h>
+
+#include <stdarg.h>
+
+typedef enum {
+        METRIC_CONN_TIME,
+        METRIC_SERVER_VERSION,
+        METRIC_QUERY_RESULT,
+        METRIC_QUERY_TIME,
+} np_dbi_metric_t;
+
+typedef enum {
+        TYPE_NUMERIC,
+        TYPE_STRING,
+} np_dbi_type_t;
+
+typedef struct {
+        char *key;
+        char *value;
+} driver_option_t;
+
+char *host = NULL;
+int verbose = 0;
+
+char *warning_range = NULL;
+char *critical_range = NULL;
+thresholds *dbi_thresholds = NULL;
+
+char *expect = NULL;
+
+regex_t expect_re;
+char *expect_re_str = NULL;
+int expect_re_cflags = 0;
+
+np_dbi_metric_t metric = METRIC_QUERY_RESULT;
+np_dbi_type_t type = TYPE_NUMERIC;
+
+char *np_dbi_driver = NULL;
+driver_option_t *np_dbi_options = NULL;
+int np_dbi_options_num = 0;
+char *np_dbi_database = NULL;
+char *np_dbi_query = NULL;
+
+int process_arguments (int, char **);
+int validate_arguments (void);
+void print_usage (void);
+void print_help (void);
+
+double timediff (struct timeval, struct timeval);
+
+void np_dbi_print_error (dbi_conn, char *, ...);
+
+int do_query (dbi_conn, const char **, double *, double *);
+
+int
+main (int argc, char **argv)
+{
+        int status = STATE_UNKNOWN;
+
+        dbi_driver driver;
+        dbi_conn conn;
+
+        unsigned int server_version;
+
+        struct timeval start_timeval, end_timeval;
+        double conn_time = 0.0;
+        double query_time = 0.0;
+
+        const char *query_val_str = NULL;
+        double query_val = 0.0;
+
+        int i;
+
+        setlocale (LC_ALL, "");
+        bindtextdomain (PACKAGE, LOCALEDIR);
+        textdomain (PACKAGE);
+
+        /* Parse extra opts if any */
+        argv = np_extra_opts (&argc, argv, progname);
+
+        if (process_arguments (argc, argv) == ERROR)
+                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);
+
+        if (verbose > 2)
+                printf ("Initializing DBI\n");
+
+        if (dbi_initialize (NULL) < 0) {
+                printf ("UNKNOWN - failed to initialize DBI; possibly you don't have any drivers installed.\n");
+                return STATE_UNKNOWN;
+        }
+
+        if (verbose)
+                printf ("Opening DBI driver '%s'\n", np_dbi_driver);
+
+        driver = dbi_driver_open (np_dbi_driver);
+        if (! driver) {
+                printf ("UNKNOWN - failed to open DBI driver '%s'; possibly it's not installed.\n",
+                                np_dbi_driver);
+
+                printf ("Known drivers:\n");
+                for (driver = dbi_driver_list (NULL); driver; driver = dbi_driver_list (driver)) {
+                        printf (" - %s\n", dbi_driver_get_name (driver));
+                }
+                return STATE_UNKNOWN;
+        }
+
+        /* make a connection to the database */
+        gettimeofday (&start_timeval, NULL);
+
+        conn = dbi_conn_open (driver);
+        if (! conn) {
+                printf ("UNKNOWN - failed top open connection object.\n");
+                dbi_conn_close (conn);
+                return STATE_UNKNOWN;
+        }
+
+        for (i = 0; i < np_dbi_options_num; ++i) {
+                const char *opt;
+
+                if (verbose > 1)
+                        printf ("Setting DBI driver option '%s' to '%s'\n",
+                                        np_dbi_options[i].key, np_dbi_options[i].value);
+
+                if (! dbi_conn_set_option (conn, np_dbi_options[i].key, np_dbi_options[i].value))
+                        continue;
+                /* else: status != 0 */
+
+                np_dbi_print_error (conn, "UNKNOWN - failed to set option '%s' to '%s'",
+                                np_dbi_options[i].key, np_dbi_options[i].value);
+                printf ("Known driver options:\n");
+
+                for (opt = dbi_conn_get_option_list (conn, NULL); opt;
+                                opt = dbi_conn_get_option_list (conn, opt)) {
+                        printf (" - %s\n", opt);
+                }
+                dbi_conn_close (conn);
+                return STATE_UNKNOWN;
+        }
+
+        if (host) {
+                if (verbose > 1)
+                        printf ("Setting DBI driver option 'host' to '%s'\n", host);
+                dbi_conn_set_option (conn, "host", host);
+        }
+
+        if (verbose) {
+                const char *dbname, *host;
+
+                dbname = dbi_conn_get_option (conn, "dbname");
+                host = dbi_conn_get_option (conn, "host");
+
+                if (! dbname)
+                        dbname = "<unspecified>";
+                if (! host)
+                        host = "<unspecified>";
+
+                printf ("Connecting to database '%s' at host '%s'\n",
+                                dbname, host);
+        }
+
+        if (dbi_conn_connect (conn) < 0) {
+                np_dbi_print_error (conn, "UNKOWN - failed to connect to database");
+                return STATE_UNKNOWN;
+        }
+
+        gettimeofday (&end_timeval, NULL);
+        conn_time = timediff (start_timeval, end_timeval);
+
+        server_version = dbi_conn_get_engine_version (conn);
+        if (verbose)
+                printf ("Connected to server version %u\n", server_version);
+
+        if (metric == METRIC_SERVER_VERSION)
+                status = get_status (server_version, dbi_thresholds);
+
+        if (verbose)
+                printf ("Time elapsed: %f\n", conn_time);
+
+        if (metric == METRIC_CONN_TIME)
+                status = get_status (conn_time, dbi_thresholds);
+
+        /* select a database */
+        if (np_dbi_database) {
+                if (verbose > 1)
+                        printf ("Selecting database '%s'\n", np_dbi_database);
+
+                if (dbi_conn_select_db (conn, np_dbi_database)) {
+                        np_dbi_print_error (conn, "UNKOWN - failed to select database '%s'",
+                                        np_dbi_database);
+                        return STATE_UNKNOWN;
+                }
+        }
+
+        if (np_dbi_query) {
+                /* execute query */
+                status = do_query (conn, &query_val_str, &query_val, &query_time);
+                if (status != STATE_OK)
+                        /* do_query prints an error message in this case */
+                        return status;
+
+                if (metric == METRIC_QUERY_RESULT) {
+                        if (expect) {
+                                if ((! query_val_str) || strcmp (query_val_str, expect))
+                                        status = STATE_CRITICAL;
+                                else
+                                        status = STATE_OK;
+                        }
+                        else if (expect_re_str) {
+                                int err;
+
+                                err = regexec (&expect_re, query_val_str, 0, NULL, /* flags = */ 0);
+                                if (! err)
+                                        status = STATE_OK;
+                                else if (err == REG_NOMATCH)
+                                        status = STATE_CRITICAL;
+                                else {
+                                        char errmsg[1024];
+                                        regerror (err, &expect_re, errmsg, sizeof (errmsg));
+                                        printf ("ERROR - failed to execute regular expression: %s\n",
+                                                        errmsg);
+                                        status = STATE_CRITICAL;
+                                }
+                        }
+                        else
+                                status = get_status (query_val, dbi_thresholds);
+                }
+                else if (metric == METRIC_QUERY_TIME)
+                        status = get_status (query_time, dbi_thresholds);
+        }
+
+        if (verbose)
+                printf("Closing connection\n");
+        dbi_conn_close (conn);
+
+        /* In case of METRIC_QUERY_RESULT, isnan(query_val) indicates an error
+         * which should have been reported and handled (abort) before
+         * ... unless we expected a string to be returned */
+        assert ((metric != METRIC_QUERY_RESULT) || (! isnan (query_val))
+                        || (type == TYPE_STRING));
+
+        assert ((type != TYPE_STRING) || (expect || expect_re_str));
+
+        printf ("%s - connection time: %fs", state_text (status), conn_time);
+        if (np_dbi_query) {
+                if (type == TYPE_STRING) {
+                        assert (expect || expect_re_str);
+                        printf (", '%s' returned '%s' in %fs", np_dbi_query,
+                                        query_val_str ? query_val_str : "<nothing>", query_time);
+                        if (status != STATE_OK) {
+                                if (expect)
+                                        printf (" (expected '%s')", expect);
+                                else if (expect_re_str)
+                                        printf (" (expected regex /%s/%s)", expect_re_str,
+                                                        ((expect_re_cflags & REG_ICASE) ? "i" : ""));
+                        }
+                }
+                else if (isnan (query_val))
+                        printf (", '%s' query execution time: %fs", np_dbi_query, query_time);
+                else
+                        printf (", '%s' returned %f in %fs", np_dbi_query, query_val, query_time);
+        }
+
+        printf (" | conntime=%fs;%s;%s;0; server_version=%u;%s;%s;0;", conn_time,
+                        ((metric == METRIC_CONN_TIME) && warning_range) ? warning_range : "",
+                        ((metric == METRIC_CONN_TIME) && critical_range) ? critical_range : "",
+                        server_version,
+                        ((metric == METRIC_SERVER_VERSION) && warning_range) ? warning_range : "",
+                        ((metric == METRIC_SERVER_VERSION) && critical_range) ? critical_range : "");
+        if (np_dbi_query) {
+                if (! isnan (query_val)) /* this is also true when -e is used */
+                        printf (" query=%f;%s;%s;;", query_val,
+                                        ((metric == METRIC_QUERY_RESULT) && warning_range) ? warning_range : "",
+                                        ((metric == METRIC_QUERY_RESULT) && critical_range) ? critical_range : "");
+                printf (" querytime=%fs;%s;%s;0;", query_time,
+                                ((metric == METRIC_QUERY_TIME) && warning_range) ? warning_range : "",
+                                ((metric == METRIC_QUERY_TIME) && critical_range) ? critical_range : "");
+        }
+        printf ("\n");
+        return status;
+}
+
+/* process command-line arguments */
+int
+process_arguments (int argc, char **argv)
+{
+        int c;
+
+        int option = 0;
+        static struct option longopts[] = {
+                STD_LONG_OPTS,
+
+                {"expect", required_argument, 0, 'e'},
+                {"regex", required_argument, 0, 'r'},
+                {"regexi", required_argument, 0, 'R'},
+                {"metric", required_argument, 0, 'm'},
+                {"driver", required_argument, 0, 'd'},
+                {"option", required_argument, 0, 'o'},
+                {"query", required_argument, 0, 'q'},
+                {"database", required_argument, 0, 'D'},
+                {0, 0, 0, 0}
+        };
+
+        while (1) {
+                c = getopt_long (argc, argv, "Vvht:c:w:e:r:R:m:H:d:o:q:D:",
+                                longopts, &option);
+
+                if (c == EOF)
+                        break;
+
+                switch (c) {
+                case '?':     /* usage */
+                        usage5 ();
+                case 'h':     /* help */
+                        print_help ();
+                        exit (STATE_OK);
+                case 'V':     /* version */
+                        print_revision (progname, NP_VERSION);
+                        exit (STATE_OK);
+
+                case 'c':     /* critical range */
+                        critical_range = optarg;
+                        type = TYPE_NUMERIC;
+                        break;
+                case 'w':     /* warning range */
+                        warning_range = optarg;
+                        type = TYPE_NUMERIC;
+                        break;
+                case 'e':
+                        expect = optarg;
+                        type = TYPE_STRING;
+                        break;
+                case 'R':
+                        expect_re_cflags = REG_ICASE;
+                        /* fall through */
+                case 'r':
+                        {
+                                int err;
+
+                                expect_re_cflags |= REG_EXTENDED | REG_NOSUB | REG_NEWLINE;
+                                expect_re_str = optarg;
+                                type = TYPE_STRING;
+
+                                err = regcomp (&expect_re, expect_re_str, expect_re_cflags);
+                                if (err) {
+                                        char errmsg[1024];
+                                        regerror (err, &expect_re, errmsg, sizeof (errmsg));
+                                        printf ("ERROR - failed to compile regular expression: %s\n",
+                                                        errmsg);
+                                        return ERROR;
+                                }
+                                break;
+                        }
+
+                case 'm':
+                        if (! strcasecmp (optarg, "CONN_TIME"))
+                                metric = METRIC_CONN_TIME;
+                        else if (! strcasecmp (optarg, "SERVER_VERSION"))
+                                metric = METRIC_SERVER_VERSION;
+                        else if (! strcasecmp (optarg, "QUERY_RESULT"))
+                                metric = METRIC_QUERY_RESULT;
+                        else if (! strcasecmp (optarg, "QUERY_TIME"))
+                                metric = METRIC_QUERY_TIME;
+                        else
+                                usage2 (_("Invalid metric"), optarg);
+                        break;
+                case 't':     /* timeout */
+                        if (!is_intnonneg (optarg))
+                                usage2 (_("Timeout interval must be a positive integer"), optarg);
+                        else
+                                timeout_interval = atoi (optarg);
+
+                case 'H':     /* host */
+                        if (!is_host (optarg))
+                                usage2 (_("Invalid hostname/address"), optarg);
+                        else
+                                host = optarg;
+                        break;
+                case 'v':
+                        verbose++;
+                        break;
+
+                case 'd':
+                        np_dbi_driver = optarg;
+                        break;
+                case 'o':
+                        {
+                                driver_option_t *new;
+
+                                char *k, *v;
+
+                                k = optarg;
+                                v = strchr (k, (int)'=');
+
+                                if (! v)
+                                        usage2 (_("Option must be '<key>=<value>'"), optarg);
+
+                                *v = '\0';
+                                ++v;
+
+                                new = realloc (np_dbi_options,
+                                                (np_dbi_options_num + 1) * sizeof (*new));
+                                if (! new) {
+                                        printf ("UNKOWN - failed to reallocate memory\n");
+                                        exit (STATE_UNKNOWN);
+                                }
+
+                                np_dbi_options = new;
+                                new = np_dbi_options + np_dbi_options_num;
+                                ++np_dbi_options_num;
+
+                                new->key = k;
+                                new->value = v;
+                        }
+                        break;
+                case 'q':
+                        np_dbi_query = optarg;
+                        break;
+                case 'D':
+                        np_dbi_database = optarg;
+                        break;
+                }
+        }
+
+        set_thresholds (&dbi_thresholds, warning_range, critical_range);
+
+        return validate_arguments ();
+}
+
+int
+validate_arguments ()
+{
+        if (! np_dbi_driver)
+                usage ("Must specify a DBI driver");
+
+        if (((metric == METRIC_QUERY_RESULT) || (metric == METRIC_QUERY_TIME))
+                        && (! np_dbi_query))
+                usage ("Must specify a query to execute (metric == QUERY_RESULT)");
+
+        if ((metric != METRIC_CONN_TIME)
+                        && (metric != METRIC_SERVER_VERSION)
+                        && (metric != METRIC_QUERY_RESULT)
+                        && (metric != METRIC_QUERY_TIME))
+                usage ("Invalid metric specified");
+
+        if (expect && (warning_range || critical_range || expect_re_str))
+                usage ("Do not mix -e and -w/-c/-r/-R");
+
+        if (expect_re_str && (warning_range || critical_range || expect))
+                usage ("Do not mix -r/-R and -w/-c/-e");
+
+        if (expect && (metric != METRIC_QUERY_RESULT))
+                usage ("Option -e requires metric QUERY_RESULT");
+
+        if (expect_re_str && (metric != METRIC_QUERY_RESULT))
+                usage ("Options -r/-R require metric QUERY_RESULT");
+
+        return OK;
+}
+
+void
+print_help (void)
+{
+        print_revision (progname, NP_VERSION);
+
+        printf (COPYRIGHT, copyright, email);
+
+        printf (_("This program connects to an (SQL) database using DBI and checks the\n"
+                        "specified metric against threshold levels. The default metric is\n"
+                        "the result of the specified query.\n"));
+
+        printf ("\n\n");
+
+        print_usage ();
+
+        printf (UT_HELP_VRSN);
+/* include this conditionally to avoid 'zero-length printf format string'
+ * compiler warnings */
+#ifdef NP_EXTRA_OPTS
+        printf (UT_EXTRA_OPTS);
+#endif
+        printf ("\n");
+
+        printf (" %s\n", "-d, --driver=STRING");
+        printf ("    %s\n", _("DBI driver to use"));
+        printf (" %s\n", "-o, --option=STRING");
+        printf ("    %s\n", _("DBI driver options"));
+        printf (" %s\n", "-q, --query=STRING");
+        printf ("    %s\n", _("query to execute"));
+        printf ("\n");
+
+        printf (UT_WARN_CRIT_RANGE);
+        printf (" %s\n", "-e, --expect=STRING");
+        printf ("    %s\n", _("String to expect as query result"));
+        printf ("    %s\n", _("Do not mix with -w, -c, -r, or -R!"));
+        printf (" %s\n", "-r, --regex=REGEX");
+        printf ("    %s\n", _("Extended POSIX regular expression to check query result against"));
+        printf ("    %s\n", _("Do not mix with -w, -c, -e, or -R!"));
+        printf (" %s\n", "-R, --regexi=REGEX");
+        printf ("    %s\n", _("Case-insensitive extended POSIX regex to check query result against"));
+        printf ("    %s\n", _("Do not mix with -w, -c, -e, or -r!"));
+        printf (" %s\n", "-m, --metric=METRIC");
+        printf ("    %s\n", _("Metric to check thresholds against. Available metrics:"));
+        printf ("    CONN_TIME    - %s\n", _("time used for setting up the database connection"));
+        printf ("    QUERY_RESULT - %s\n", _("result (first column of first row) of the query"));
+        printf ("    QUERY_TIME   - %s\n", _("time used to execute the query"));
+        printf ("                   %s\n", _("(ignore the query result)"));
+        printf ("\n");
+
+        printf (UT_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
+
+        printf (UT_VERBOSE);
+
+        printf ("\n");
+        printf (" %s\n", _("A DBI driver (-d option) is required. If the specified metric operates"));
+        printf (" %s\n\n", _("on a query, one has to be specified (-q option)."));
+
+        printf (" %s\n", _("This plugin connects to an (SQL) database using libdbi and, optionally,"));
+        printf (" %s\n", _("executes the specified query. The first column of the first row of the"));
+        printf (" %s\n", _("result will be parsed and, in QUERY_RESULT mode, compared with the"));
+        printf (" %s\n", _("warning and critical ranges. The result from the query has to be numeric"));
+        printf (" %s\n\n", _("(strings representing numbers are fine)."));
+
+        printf (" %s\n", _("The number and type of required DBI driver options depends on the actual"));
+        printf (" %s\n", _("driver. See its documentation at http://libdbi-drivers.sourceforge.net/"));
+        printf (" %s\n\n", _("for details."));
+
+        printf (" %s\n", _("Examples:"));
+        printf ("  check_dbi -d pgsql -o username=postgres -m QUERY_RESULT \\\n");
+        printf ("    -q 'SELECT COUNT(*) FROM pg_stat_activity' -w 5 -c 10\n");
+        printf ("  Warning if more than five connections; critical if more than ten.\n\n");
+
+        printf ("  check_dbi -d mysql -H localhost -o username=user -o password=secret \\\n");
+        printf ("    -q 'SELECT COUNT(*) FROM logged_in_users -w 5:20 -c 0:50\n");
+        printf ("  Warning if less than 5 or more than 20 users are logged in; critical\n");
+        printf ("  if more than 50 users.\n\n");
+
+        printf ("  check_dbi -d firebird -o username=user -o password=secret -o dbname=foo \\\n");
+        printf ("    -m CONN_TIME -w 0.5 -c 2\n");
+        printf ("  Warning if connecting to the database takes more than half of a second;\n");
+        printf ("  critical if it takes more than 2 seconds.\n\n");
+
+        printf ("  check_dbi -d mysql -H localhost -o username=user \\\n");
+        printf ("    -q 'SELECT concat(@@version, \" \", @@version_comment)' \\\n");
+        printf ("    -r '^5\\.[01].*MySQL Enterprise Server'\n");
+        printf ("  Critical if the database server is not a MySQL enterprise server in either\n");
+        printf ("  version 5.0.x or 5.1.x.\n\n");
+
+        printf ("  check_dbi -d pgsql -u username=user -m SERVER_VERSION \\\n");
+        printf ("    -w 090000:090099 -c 090000:090199\n");
+        printf ("  Warn if the PostgreSQL server version is not 9.0.x; critical if the version\n");
+        printf ("  is less than 9.x or higher than 9.1.x.\n");
+
+        printf (UT_SUPPORT);
+}
+
+void
+print_usage (void)
+{
+        printf ("%s\n", _("Usage:"));
+        printf ("%s -d <DBI driver> [-o <DBI driver option> [...]] [-q <query>]\n", progname);
+        printf (" [-H <host>] [-c <critical range>] [-w <warning range>] [-m <metric>]\n");
+        printf (" [-e <string>] [-r|-R <regex>]\n");
+}
+
+#define CHECK_IGNORE_ERROR(s) \
+        do { \
+                if (metric != METRIC_QUERY_RESULT) \
+                        return (s); \
+        } while (0)
+
+const char *
+get_field_str (dbi_conn conn, dbi_result res, unsigned short field_type)
+{
+        const char *str;
+
+        if (field_type != DBI_TYPE_STRING) {
+                printf ("CRITICAL - result value is not a string\n");
+                return NULL;
+        }
+
+        str = dbi_result_get_string_idx (res, 1);
+        if ((! str) || (strcmp (str, "ERROR") == 0)) {
+                CHECK_IGNORE_ERROR (NULL);
+                np_dbi_print_error (conn, "CRITICAL - failed to fetch string value");
+                return NULL;
+        }
+
+        if ((verbose && (type == TYPE_STRING)) || (verbose > 2))
+                printf ("Query returned string '%s'\n", str);
+        return str;
+}
+
+double
+get_field (dbi_conn conn, dbi_result res, unsigned short *field_type)
+{
+        double val = NAN;
+
+        if (*field_type == DBI_TYPE_INTEGER) {
+                val = (double)dbi_result_get_longlong_idx (res, 1);
+        }
+        else if (*field_type == DBI_TYPE_DECIMAL) {
+                val = dbi_result_get_double_idx (res, 1);
+        }
+        else if (*field_type == DBI_TYPE_STRING) {
+                const char *val_str;
+                char *endptr = NULL;
+
+                val_str = get_field_str (conn, res, *field_type);
+                if (! val_str) {
+                        CHECK_IGNORE_ERROR (NAN);
+                        *field_type = DBI_TYPE_ERROR;
+                        return NAN;
+                }
+
+                val = strtod (val_str, &endptr);
+                if (endptr == val_str) {
+                        CHECK_IGNORE_ERROR (NAN);
+                        printf ("CRITICAL - result value is not a numeric: %s\n", val_str);
+                        *field_type = DBI_TYPE_ERROR;
+                        return NAN;
+                }
+                else if ((endptr != NULL) && (*endptr != '\0')) {
+                        if (verbose)
+                                printf ("Garbage after value: %s\n", endptr);
+                }
+        }
+        else {
+                CHECK_IGNORE_ERROR (NAN);
+                printf ("CRITICAL - cannot parse value of type %s (%i)\n",
+                                (*field_type == DBI_TYPE_BINARY)
+                                        ? "BINARY"
+                                        : (*field_type == DBI_TYPE_DATETIME)
+                                                ? "DATETIME"
+                                                : "<unknown>",
+                                *field_type);
+                *field_type = DBI_TYPE_ERROR;
+                return NAN;
+        }
+        return val;
+}
+
+double
+get_query_result (dbi_conn conn, dbi_result res, const char **res_val_str, double *res_val)
+{
+        unsigned short field_type;
+        double val = NAN;
+
+        if (dbi_result_get_numrows (res) == DBI_ROW_ERROR) {
+                CHECK_IGNORE_ERROR (STATE_OK);
+                np_dbi_print_error (conn, "CRITICAL - failed to fetch rows");
+                return STATE_CRITICAL;
+        }
+
+        if (dbi_result_get_numrows (res) < 1) {
+                CHECK_IGNORE_ERROR (STATE_OK);
+                printf ("WARNING - no rows returned\n");
+                return STATE_WARNING;
+        }
+
+        if (dbi_result_get_numfields (res) == DBI_FIELD_ERROR) {
+                CHECK_IGNORE_ERROR (STATE_OK);
+                np_dbi_print_error (conn, "CRITICAL - failed to fetch fields");
+                return STATE_CRITICAL;
+        }
+
+        if (dbi_result_get_numfields (res) < 1) {
+                CHECK_IGNORE_ERROR (STATE_OK);
+                printf ("WARNING - no fields returned\n");
+                return STATE_WARNING;
+        }
+
+        if (dbi_result_first_row (res) != 1) {
+                CHECK_IGNORE_ERROR (STATE_OK);
+                np_dbi_print_error (conn, "CRITICAL - failed to fetch first row");
+                return STATE_CRITICAL;
+        }
+
+        field_type = dbi_result_get_field_type_idx (res, 1);
+        if (field_type != DBI_TYPE_ERROR) {
+                if (type == TYPE_STRING)
+                        /* the value will be freed in dbi_result_free */
+                        *res_val_str = strdup (get_field_str (conn, res, field_type));
+                else
+                        val = get_field (conn, res, &field_type);
+        }
+
+        *res_val = val;
+
+        if (field_type == DBI_TYPE_ERROR) {
+                CHECK_IGNORE_ERROR (STATE_OK);
+                np_dbi_print_error (conn, "CRITICAL - failed to fetch data");
+                return STATE_CRITICAL;
+        }
+
+        dbi_result_free (res);
+        return STATE_OK;
+}
+
+#undef CHECK_IGNORE_ERROR
+
+int
+do_query (dbi_conn conn, const char **res_val_str, double *res_val, double *res_time)
+{
+        dbi_result res;
+
+        struct timeval timeval_start, timeval_end;
+        int status = STATE_OK;
+
+        assert (np_dbi_query);
+
+        if (verbose)
+                printf ("Executing query '%s'\n", np_dbi_query);
+
+        gettimeofday (&timeval_start, NULL);
+
+        res = dbi_conn_query (conn, np_dbi_query);
+        if (! res) {
+                np_dbi_print_error (conn, "CRITICAL - failed to execute query '%s'", np_dbi_query);
+                return STATE_CRITICAL;
+        }
+
+        status = get_query_result (conn, res, res_val_str, res_val);
+
+        gettimeofday (&timeval_end, NULL);
+        *res_time = timediff (timeval_start, timeval_end);
+
+        if (verbose)
+                printf ("Time elapsed: %f\n", *res_time);
+
+        return status;
+}
+
+double
+timediff (struct timeval start, struct timeval end)
+{
+        double diff;
+
+        while (start.tv_usec > end.tv_usec) {
+                --end.tv_sec;
+                end.tv_usec += 1000000;
+        }
+        diff = (double)(end.tv_sec - start.tv_sec)
+                + (double)(end.tv_usec - start.tv_usec) / 1000000.0;
+        return diff;
+}
+
+void
+np_dbi_print_error (dbi_conn conn, char *fmt, ...)
+{
+        const char *errmsg = NULL;
+        va_list ap;
+
+        va_start (ap, fmt);
+
+        dbi_conn_error (conn, &errmsg);
+        vprintf (fmt, ap);
+        printf (": %s\n", errmsg);
+
+        va_end (ap);
+}
+