nagios-plugins/plugins/check_dns.c

/*****************************************************************************
* 
* Nagios check_dns plugin
* 
* License: GPL
* Copyright (c) 2000-2018 Nagios Plugins Development Team
* 
* Description:
* 
* This file contains the check_dns plugin
* 
* LIMITATION: nslookup on Solaris 7 can return output over 2 lines, which
* will not be picked up by this plugin
* 
* 
* 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/>.
* 
* 
*****************************************************************************/
#define IF_RECORD(label, querytype, verb_str, comp_str) if (strstr (chld_out.line[i], label) && (strncmp(query_type, querytype, query_size) == 0 || strncmp(query_type, "-querytype=ANY", query_size) == 0)) { \
      if (verbose) { \
          printf(verb_str); \
      } \
      temp_buffer = rindex (chld_out.line[i], comp_str); \
      addresses[n_addresses++] = check_new_address(temp_buffer); \
      memset(query_found, '\0', sizeof(query_found)); \
      strncpy(query_found, querytype, sizeof(query_found)); 

const char *progname = "check_dns";
const char *copyright = "2000-2018";
const char *email = "devel@nagios-plugins.org";

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

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

/* Allow up to 4096 input length, this is helpful
   when the TXT records returned have multiple 255 legth values returned */
#define ADDRESS_LENGTH 4096
char query_address[ADDRESS_LENGTH] = "";
char dns_server[ADDRESS_LENGTH] = "";
char tmp_dns_server[ADDRESS_LENGTH] = "";
char ptr_server[ADDRESS_LENGTH] = "";
char query_type[32] = "";
int query_set = FALSE;
int verbose = FALSE;
char **expected_address = NULL;
int expected_address_cnt = 0;

int expect_authority = FALSE;
int accept_cname = FALSE;
thresholds *time_thresholds = NULL;


static int
qstrcmp(const void *p1, const void *p2)
{
    /* The actual arguments to this function are "pointers to
       pointers to char", but strcmp() arguments are "pointers
       to char", hence the following cast plus dereference */
    return strcmp(* (char * const *) p1, * (char * const *) p2);
}


char *
check_new_address(char *temp_buffer)
{
    temp_buffer++;
    /* Strip leading spaces */
    for (; *temp_buffer != '\0' && *temp_buffer == ' '; temp_buffer++) {
        /* NOOP */;
    }

    strip(temp_buffer);
    if (temp_buffer==NULL || strlen(temp_buffer)==0) {
        die (STATE_CRITICAL, "%s%s%s\n", _("DNS CRITICAL - '"), NSLOOKUP_COMMAND, _("' returned empty host name string"));
    }

    return temp_buffer;
}


int
main (int argc, char **argv)
{
    char *command_line = NULL;
    char input_buffer[MAX_INPUT_BUFFER];
    char *address = NULL; /* comma separated str with addrs/ptrs (sorted) */
    char **addresses = NULL;
    int n_addresses = 0;
    char *msg = NULL;
    char query_found[24] = "";
    int query_size = 24;
    char *temp_buffer = NULL;
    int non_authoritative = FALSE;
    int result = STATE_UNKNOWN;
    double elapsed_time;
    long microsec;
    struct timeval tv;
    int parse_address = FALSE; /* This flag scans for Address: but only after Name: */
    output chld_out, chld_err;
    size_t i;

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

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

    /* Parse extra opts if any */
    argv=np_extra_opts (&argc, argv, progname);

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

    /* get the command to run */
    xasprintf (&command_line, "%s %s %s %s", NSLOOKUP_COMMAND, query_type, query_address, dns_server);

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

    if (verbose) {
        printf ("%s\n", command_line);
    }

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

    /* scan stdout */
    for(i = 0; i < chld_out.lines; i++) {
        if (addresses == NULL) {
            addresses = malloc(sizeof(*addresses)*10);
        }
        else if (!(n_addresses % 10)) {
            addresses = realloc(addresses,sizeof(*addresses) * (n_addresses + 10));
        }

        if (verbose) {
            puts(chld_out.line[i]);
        }

        /* bug ID: 2946553 - Older versions of bind will use all available dns
        + servers, we have to match the one specified */
        if (strlen(dns_server) > 0 && strstr(chld_out.line[i], "Server:")) {
            temp_buffer = strchr(chld_out.line[i], ':');
            temp_buffer++;

            if (temp_buffer > (char *)1) {
                /* Strip leading tabs */
                for (; *temp_buffer != '\0' && *temp_buffer == '\t'; temp_buffer++) {
                    /* NOOP */;
                }

                strip(temp_buffer);
                if (temp_buffer==NULL || strlen(temp_buffer)==0) {
                    die (STATE_CRITICAL, "%s%s%s\n", _("DNS CRITICAL - '"), NSLOOKUP_COMMAND, _("' returned empty server string"));
                }

                if (strcmp(temp_buffer, dns_server) != 0) {
                    die (STATE_CRITICAL, "%s %s\n", _("DNS CRITICAL - No response from DNS server:"), dns_server);
                }
            }
        }
        /* Provide the server name\ip to error_scan when not using -s */
        else if (strlen(tmp_dns_server) == 0) {
            temp_buffer = strchr(chld_out.line[i], ':');
            temp_buffer++;
            if (temp_buffer > (char *)1) {
                /* Strip leading tabs */
                for (; *temp_buffer != '\0' && *temp_buffer == '\t'; temp_buffer++) {
                    /* NOOP */;
                }
                strip(temp_buffer);
                strncpy(tmp_dns_server, temp_buffer, ADDRESS_LENGTH);
            }
        }

        if (strstr (chld_out.line[i], "Authoritative answers can be found from:")) {
            break;
        }
        /* the server is responding, we just got the host name...*/
        if (strstr (chld_out.line[i], "Name:")) {
            parse_address = TRUE;
        }
        /* begin handling types of records */
        IF_RECORD("AAAA address", "-querytype=AAAA", "Found AAAA record\n", ' ') }
        else IF_RECORD("exchanger =", "-querytype=MX", "Found MX record\n", '=') }
        else IF_RECORD("service =", "-querytype=SRV", "Found SRV record\n", ' ') }
        else IF_RECORD("nameserver =", "-querytype=NS", "Found NS record\n", ' ') }
        else IF_RECORD("dname =", "-querytype=DNAME", "Found DNAME record\n", ' ') }
        else IF_RECORD("protocol =", "-querytype=WKS", "Found WKS record\n", ' ') }
        else if (strstr (chld_out.line[i], "text =") && (strncmp(query_type, "-querytype=TXT", query_size) == 0 || strncmp(query_type, "-querytype=ANY", query_size) == 0)) {
            if (verbose) {
                printf("Found TXT record\n");
            }
            temp_buffer = index(chld_out.line[i], '"');
            --temp_buffer;
            addresses[n_addresses++] = check_new_address(temp_buffer);
            memset(query_found, '\0', sizeof(query_found));
            strncpy(query_found, "-querytype=TXT", sizeof(query_found)); 
        }

        /* only matching for origin records, if requested other fields could be included at a later date */
        else IF_RECORD("origin =", "-querytype=SOA", "Found SOA record\n", ' ') }
        /* cnames cannot use macro as we must check for accepting them separately */
        else if (accept_cname && strstr (chld_out.line[i], "canonical name =") && (strncmp(query_type, "-querytype=CNAME", query_size) == 0 || strncmp(query_type, "-querytype=ANY", query_size) == 0)) {
            if (verbose) {
                printf("Found CNAME record\n");
            }
            temp_buffer = index (chld_out.line[i], '=');
            addresses[n_addresses++] = check_new_address(temp_buffer);
            strncpy(query_found, "-querytype=CNAME", sizeof(query_found));
        }
        /* does not need strncmp as we want A at all times unless another record match */
        else if (parse_address == TRUE && (strstr (chld_out.line[i], "Address:") || strstr (chld_out.line[i], "Addresses:"))) {
            temp_buffer = index (chld_out.line[i], ':');
            char *temp_address = check_new_address(temp_buffer);
            addresses[n_addresses++] = temp_address;
            /* Bind 9.11.x onwards reports AAAA records the same as A records */
            /* It is assumed that nslookup returns a valid IPv4 or IPv6 address */
            /* Hence we'll look for a colon : in the address to detect an IPv6 address */
            if (strstr(temp_address, ":")) {
                if (verbose) {
                    printf("Found AAAA record\n");
                }
                strncpy(query_found, "-querytype=AAAA", sizeof(query_found));
            }
            else {
                if (verbose) {
                    printf("Found A record\n");
                }
                strncpy(query_found, "-querytype=A", sizeof(query_found));
            }
        }
        /* must be after other records with "name" as an identifier, as ptr does not spefify */
        else IF_RECORD("name =", "-querytype=PTR", "Found PTR record\n", ' ') }
        /* needed for non-query ptr\reverse lookup checks */
        else if (strstr(chld_out.line[i], ".in-addr.arpa") && !query_set) {
            if ((temp_buffer = strstr(chld_out.line[i], "name = "))) {
                addresses[n_addresses++] = strdup(temp_buffer);
            }
            else {
                xasprintf(&msg, "%s %s %s %s", _("Warning plugin error"));
                result = STATE_WARNING;
            }
        }

        if (strstr (chld_out.line[i], _("Non-authoritative answer:"))) {
            non_authoritative = TRUE;
        }

        int tmp = error_scan(chld_out.line[i]);
        if (result == STATE_UNKNOWN || result < tmp) {
            result = tmp;
            if (result != STATE_OK) {
                msg = strchr (chld_out.line[i], ':');
                if (msg) {
                    msg++;
                }
                else {
                    msg = chld_out.line[i];
                }
                break;
            }
        }
    }  /*This is the end of the scan stdout loop */

    /* scan stderr */
    for(i = 0; i < chld_err.lines; i++) {
        if (verbose) {
            puts(chld_err.line[i]);
        }

        if (error_scan (chld_err.line[i]) != STATE_OK) {
            result = max_state (result, error_scan (chld_err.line[i]));
            msg = strchr(chld_err.line[i], ':');
            if(msg) {
                msg++;
            }
            else {
                msg = chld_err.line[i];
            }
        }
    }

    if (addresses) {
        int i,slen;
        char *adrp;
        qsort(addresses, n_addresses, sizeof(*addresses), qstrcmp);
        for(i=0, slen=1; i < n_addresses; i++) {
            slen += strlen(addresses[i])+1;
        }

        adrp = address = malloc(slen);
        for(i=0; i < n_addresses; i++) {
            if (i) *adrp++ = ',';
            strcpy(adrp, addresses[i]);
            adrp += strlen(addresses[i]);
        }
        *adrp = 0;
      }
    else {
        die (STATE_CRITICAL, "%s%s%s\n", _("DNS CRITICAL - '"), NSLOOKUP_COMMAND, _("' msg parsing exited with no address"));
    }

    /* compare to expected address */
    if (result == STATE_OK && expected_address_cnt > 0) {
        result = STATE_CRITICAL;
        temp_buffer = "";
        for (i=0; i<expected_address_cnt; i++) {
            /* check if we get a match and prepare an error string */
            if (strcasecmp(address, expected_address[i]) == 0) result = STATE_OK;
            xasprintf(&temp_buffer, "%s%s; ", temp_buffer, expected_address[i]);
        }
        if (result == STATE_CRITICAL) {
            /* Strip off last semicolon... */
            temp_buffer[strlen(temp_buffer)-2] = '\0';
            xasprintf(&msg, "%s%s%s%s%s", _("expected '"), temp_buffer, _("' but got '"), address, "'");
        }
    }

    /* check if authoritative */
    if (result == STATE_OK && expect_authority && non_authoritative) {
        result = STATE_CRITICAL;

        if (strncmp(dns_server, "", 1)) {
            xasprintf(&msg, "%s %s %s %s", _("server"), dns_server, _("is not authoritative for"), query_address);
        }
        else {
            xasprintf(&msg, "%s %s", _("there is no authoritative server for"), query_address);
        }
    }

    /* compare query type to query found, if query type is ANY we can skip as any record is accepted*/
    if (result == STATE_OK && strncmp(query_type, "", 1) && (strncmp(query_type, "-querytype=ANY", 15) != 0)) {
        if (strncmp(query_type, query_found, 16) != 0) {
          if (verbose) {
              printf( "%s %s %s %s %s\n", _("Failed query for"), query_type, _("only found"), query_found, _(", or nothing"));
          }
          result = STATE_CRITICAL;
          xasprintf(&msg, "%s %s %s %s", _("query type of"), query_type, _("was not found for"), query_address);
        }
    }

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

    if (result == STATE_OK) {
        result = get_status(elapsed_time, time_thresholds);
        if (result == STATE_OK) {
            printf ("%s %s: ", _("DNS"), _("OK"));
        }
        else if (result == STATE_WARNING) {
            printf ("%s %s: ", _("DNS"), _("WARNING"));
        }
        else if (result == STATE_CRITICAL) {
            printf ("%s %s: ", _("DNS"), _("CRITICAL"));
        }
        printf (ngettext("%.3f second response time", "%.3f seconds response time", elapsed_time), elapsed_time);
        printf (". %s %s %s", query_address, _("returns"), address);
        if ((time_thresholds->warning != NULL) && (time_thresholds->critical != NULL)) {
            printf ("|%s\n", fperfdata ("time", elapsed_time, "s",
                    TRUE, time_thresholds->warning->end,
                    TRUE, time_thresholds->critical->end,
                    TRUE, 0, FALSE, 0));
        }
        else if ((time_thresholds->warning == NULL) && (time_thresholds->critical != NULL)) {
            printf ("|%s\n", fperfdata ("time", elapsed_time, "s",
                    FALSE, 0,
                    TRUE, time_thresholds->critical->end,
                    TRUE, 0, FALSE, 0));
        }
        else if ((time_thresholds->warning != NULL) && (time_thresholds->critical == NULL)) {
            printf ("|%s\n", fperfdata ("time", elapsed_time, "s",
                    TRUE, time_thresholds->warning->end,
                    FALSE, 0,
                    TRUE, 0, FALSE, 0));
        }
        else {
          printf ("|%s\n", fperfdata ("time", elapsed_time, "s", FALSE, 0, FALSE, 0, TRUE, 0, FALSE, 0));
        }
    }
    else if (result == STATE_WARNING) {
        printf ("%s %s\n", _("DNS WARNING -"), !strcmp (msg, "") ? _("Probably a non-existent host/domain") : msg);
    }
    else if (result == STATE_CRITICAL) {
        printf ("%s %s\n", _("DNS CRITICAL -"), !strcmp (msg, "") ? _("Probably a non-existent host/domain") : msg);
    }
    else {
        printf ("%s %s\n", _("DNS UNKNOWN -"), !strcmp (msg, "") ? _("Probably a non-existent host/domain") : msg);
    }

    return result;
}


int
error_scan (char *input_buffer)
{
    if (strstr (input_buffer, _("Note: nslookup is deprecated and may be removed from future releases.")) ||
        strstr (input_buffer, _("Consider using the `dig' or `host' programs instead.  Run nslookup with")) ||
        strstr (input_buffer, _("the `-sil[ent]' option to prevent this message from appearing.")))
    {
        return STATE_OK;
    }
    /* the DNS lookup timed out */
    else if (strcasestr (input_buffer, "connection timed out")) {
        die (STATE_CRITICAL, "%s %s %s\n", _("Connection to DNS"), (strlen(dns_server)==0)?tmp_dns_server:dns_server, _("timed out"));
    }
    /* DNS server is not running... */
    else if (strstr (input_buffer, "No response from server")) {
        die (STATE_CRITICAL, "%s %s\n", _("No response from DNS"), (strlen(dns_server)==0)?tmp_dns_server:dns_server);
    }
    /* Host name is valid, but server doesn't have records... */
    else if (strstr (input_buffer, "No records") || strstr (input_buffer, "No answer")) {
        die (STATE_CRITICAL, "%s %s %s\n", _("DNS"), (strlen(dns_server)==0)?tmp_dns_server:dns_server, _("has no records"));
    }
    /* Connection was refused */
    else if (strcasestr (input_buffer, "Connection refused") ||
             strstr (input_buffer, "Couldn't find server") ||
             strstr (input_buffer, "Refused") ||
             (strstr (input_buffer, "** server can't find") &&
              strstr (input_buffer, ": REFUSED")))
    {
        die (STATE_CRITICAL, "%s %s %s\n", _("Connection to DNS"), (strlen(dns_server)==0)?tmp_dns_server:dns_server, _("was refused"));
    }
    /* Query refused (usually by an ACL in the namserver) */
    else if (strstr (input_buffer, "Query refused")) {
        die (STATE_CRITICAL, "%s %s\n", _("Query was refused by DNS server at"), (strlen(dns_server)==0)?tmp_dns_server:dns_server);
    }
    /* No information (e.g. nameserver IP has two PTR records) */
    else if (strstr (input_buffer, "No information")) {
        die (STATE_CRITICAL, "%s %s\n", _("No information returned by DNS server at"), (strlen(dns_server)==0)?tmp_dns_server:dns_server);
    }
    /* Host or domain name does not exist */
    else if (strstr (input_buffer, "Non-existent") ||
             strstr (input_buffer, "** server can't find") ||
             strstr (input_buffer,"NXDOMAIN"))
    {
        die (STATE_CRITICAL, "%s %s %s\n", _("Domain"), query_address, _("was not found by the server"));
    }

    /* Network is unreachable */
    else if (strstr (input_buffer, "Network is unreachable")) {
        die (STATE_CRITICAL, "%s\n", _("Network is unreachable"));
    }
    /* Internal server failure */
    else if (strstr (input_buffer, "Server failure")) {
        die (STATE_CRITICAL, "%s %s\n", _("DNS failure for"), (strlen(dns_server)==0)?tmp_dns_server:dns_server);
    }
    /* Request error or the DNS lookup timed out */
    else if (strstr (input_buffer, "Format error") ||
             strstr (input_buffer, "Timed out"))
    {
        return STATE_WARNING;
    }
    return STATE_OK;
}


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

    int opt_index = 0;
    static struct option long_opts[] = {
        {"help", no_argument, 0, 'h'},
        {"version", no_argument, 0, 'V'},
        {"verbose", no_argument, 0, 'v'},
        {"timeout", required_argument, 0, 't'},
        {"hostname", required_argument, 0, 'H'},
        {"server", required_argument, 0, 's'},
        {"reverse-server", required_argument, 0, 'r'},
        {"querytype", required_argument, 0, 'q'},
        {"expected-address", required_argument, 0, 'a'},
        {"expect-authority", no_argument, 0, 'A'},
        {"accept-cname", no_argument, 0, 'n'},
        {"warning", required_argument, 0, 'w'},
        {"critical", required_argument, 0, 'c'},
        {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, "hVvAnt:H:s:r:a:q:w:c:", long_opts, &opt_index);

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

        switch (c) {
        /* help */
        case 'h':
            print_help ();
            exit (STATE_OK);
       /* version */
        case 'V':
            print_revision (progname, NP_VERSION);
            exit (STATE_OK);
        /* verbose */
        case 'v':
            verbose = TRUE;
            break;
        /* timeout period */
        case 't':
            timeout_interval = parse_timeout_string (optarg);
            break;
        /* hostname */
        case 'H':
            if (strlen (optarg) >= ADDRESS_LENGTH) {
                die (STATE_UNKNOWN, "%s\n", _("Input buffer overflow"));
            }
            strcpy (query_address, optarg);
            break;
        /* server name */
        case 's':
            /* TODO: this host_or_die check is probably unnecessary.
            * Better to confirm nslookup response matches */
            host_or_die(optarg);
            if (strlen (optarg) >= ADDRESS_LENGTH) {
                die (STATE_UNKNOWN, "%s\n", _("Input buffer overflow"));
            }
            strcpy (dns_server, optarg);
            break;
        /* reverse server name */
        case 'r':
            /* TODO: Is this host_or_die necessary? */
            host_or_die(optarg);
            if (strlen (optarg) >= ADDRESS_LENGTH) {
                die (STATE_UNKNOWN, "%s\n", _("Input buffer overflow"));
            }
            strcpy (ptr_server, optarg);
            break;
        /* expected address */
        case 'a':
            if (strlen (optarg) >= ADDRESS_LENGTH) {
                die (STATE_UNKNOWN, "%s\n", _("Input buffer overflow"));
            }
            expected_address = (char **)realloc(expected_address, (expected_address_cnt+1) * sizeof(char*));
            expected_address[expected_address_cnt] = strdup(optarg);
            expected_address_cnt++;
            break;
        /* querytype -- A or AAAA or ANY or SRV or TXT, etc. */
        case 'q':
            if (strlen (optarg) < 1 || strlen (optarg) > 5) {
                die (STATE_UNKNOWN, "%s\n", _("Missing valid querytype parameter.  Try using 'A' or 'AAAA' or 'SRV' or 'ANY'"));
            }
            strntoupper(optarg, strlen(optarg));
            strcpy(query_type, "-querytype=");
            strcat(query_type, optarg);
            query_set = TRUE;
            /* logic is set such that we must accept cnames if they are querying for them */
            if (strcmp(query_type, "-querytype=CNAME") != 0) {
                break;
            }
        /* accept cname responses as a result */
        case 'n':
            accept_cname = TRUE;
            break;
        /* expect authority */
        case 'A':
            expect_authority = TRUE;
            break;
        case 'w':
            warning = optarg;
            break;
        case 'c':
            critical = optarg;
            break;
        /* args not parsable */
        default:
            usage5();
        }
    }

    set_thresholds(&time_thresholds, warning, critical);

    return validate_arguments ();
}


int
validate_arguments ()
{
    if (query_address[0] == 0) {
        return ERROR;
    }

    /* Bind 9.11.x onwards performs a query for both A and AAAA records */
    /* The previous default behavior of nslookup was just A records. */
    /* To ensure that exisitng users of this plugin do not get incorrect results */
    /* set the querytype to A if it has not already been specified. */
    /* If an end user wants both A and AAAA then they need to use ANY. */
    if (strcmp(query_type, "") == 0) {
        /*query_type = "-querytype=A";*/
        strcpy(query_type, "-querytype=");
        strcat(query_type, "A");
        query_set = TRUE;
    }

    return OK;
}


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

    printf ("%s\n", "Copyright (c) 1999 Ethan Galstad <nagios@nagios.org>");
    printf (COPYRIGHT, copyright, email);

    printf ("%s\n", _("This plugin uses the nslookup program to obtain the IP address for the given host/domain query."));
    printf ("%s\n", _("An optional DNS server to use may be specified."));
    printf ("%s\n", _("If no DNS server is specified, the default server(s) specified in /etc/resolv.conf will be used."));

    printf ("\n\n");

    print_usage ();

    printf (UT_HELP_VRSN);
    printf (UT_EXTRA_OPTS);

    printf ("%s\n", " -H, --hostname=HOST");
    printf ("    %s\n", _("The name or address you want to query"));
    printf ("%s\n", " -s, --server=HOST");
    printf ("    %s\n", _("Optional DNS server you want to use for the lookup"));
    printf ("%s\n", " -q, --querytype=TYPE");
    printf ("    %s\n", _("Optional DNS record query type where TYPE =(A, AAAA, SRV, TXT, MX, ANY)"));
    printf ("    %s\n", _("The default query type is 'A' (IPv4 host entry)"));
    printf ("    %s\n", _("BIND 9.11.x onwards supports both 'A' and 'AAAA', if you want both use 'ANY'"));
    printf ("%s\n", " -a, --expected-address=IP-ADDRESS|HOST");
    printf ("    %s\n", _("Optional IP-ADDRESS you expect the DNS server to return. HOST must end with"));
    printf ("    %s\n", _("a dot (.). This option can be repeated multiple times (Returns OK if any"));
    printf ("    %s\n", _("value match). If multiple addresses are returned at once, you have to match"));
    printf ("    %s\n", _("the whole string of addresses separated with commas (sorted alphabetically)."));
    printf ("    %s\n", _("If you would like to test for the presence of a cname, combine with -n param."));
    printf ("%s\n", " -A, --expect-authority");
    printf ("    %s\n", _("Optionally expect the DNS server to be authoritative for the lookup"));
    printf ("%s\n", " -n, --accept-cname");
    printf ("    %s\n", _("Optionally accept cname responses as a valid result to a query"));
    printf ("    %s\n", _("The default is to ignore cname responses as part of the result"));
    printf ("%s\n", " -w, --warning=seconds");
    printf ("    %s\n", _("Return warning if elapsed time exceeds value. Default off"));
    printf ("%s\n", " -c, --critical=seconds");
    printf ("    %s\n", _("Return critical if elapsed time exceeds value. Default off"));

    printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);

    printf (UT_SUPPORT);
}


void
print_usage (void)
{
    printf ("%s\n", _("Usage:"));
    printf ("%s %s\n", progname, "-H host [-s server] [-q type ] [-a expected-address] [-A] [-n] [-t timeout] [-w warn] [-c crit]");
}