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nagios-plugins  1.4.16
Defines | Functions | Variables
check_dns.c File Reference
#include "common.h"
#include "utils.h"
#include "utils_base.h"
#include "netutils.h"
#include "runcmd.h"

Go to the source code of this file.

Defines

#define ADDRESS_LENGTH   256

Functions

int process_arguments (int, char **)
int validate_arguments (void)
int error_scan (char *)
void print_help (void)
void print_usage (void)
static int qstrcmp (const void *p1, const void *p2)
int main (int argc, char **argv)

Variables

const char * progname = "check_dns"
const char * copyright = "2000-2008"
const char * email = "nagiosplug-devel@lists.sourceforge.net"
char query_address [ADDRESS_LENGTH] = ""
char dns_server [ADDRESS_LENGTH] = ""
char ptr_server [ADDRESS_LENGTH] = ""
int verbose = FALSE
char ** expected_address = NULL
int expected_address_cnt = 0
int expect_authority = FALSE
thresholdstime_thresholds = NULL

Define Documentation

#define ADDRESS_LENGTH   256

Definition at line 48 of file check_dns.c.


Function Documentation

int error_scan ( char *  input_buffer)

Definition at line 263 of file check_dns.c.

{

  /* the DNS lookup timed out */
  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;

  /* DNS server is not running... */
  else if (strstr (input_buffer, "No response from server"))
    die (STATE_CRITICAL, _("No response from DNS %s\n"), dns_server);

  /* Host name is valid, but server doesn't have records... */
  else if (strstr (input_buffer, "No records"))
    die (STATE_CRITICAL, _("DNS %s has no records\n"), dns_server);

  /* Connection was refused */
  else if (strstr (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, _("Connection to DNS %s was refused\n"), dns_server);

  /* Query refused (usually by an ACL in the namserver) */
  else if (strstr (input_buffer, "Query refused"))
    die (STATE_CRITICAL, _("Query was refused by DNS server at %s\n"), dns_server);

  /* No information (e.g. nameserver IP has two PTR records) */
  else if (strstr (input_buffer, "No information"))
    die (STATE_CRITICAL, _("No information returned by DNS server at %s\n"), 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, _("Domain %s was not found by the server\n"), query_address);

  /* Network is unreachable */
  else if (strstr (input_buffer, "Network is unreachable"))
    die (STATE_CRITICAL, _("Network is unreachable\n"));

  /* Internal server failure */
  else if (strstr (input_buffer, "Server failure"))
    die (STATE_CRITICAL, _("DNS failure for %s\n"), 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;

}

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int main ( int  argc,
char **  argv 
)

Definition at line 70 of file check_dns.c.

{
  char *command_line = NULL;
  char input_buffer[MAX_INPUT_BUFFER];
  char *address = NULL; /* comma seperated str with addrs/ptrs (sorted) */
  char **addresses = NULL;
  int n_addresses = 0;
  char *msg = NULL;
  char *temp_buffer = NULL;
  int non_authoritative = FALSE;
  int result = STATE_UNKNOWN;
  double elapsed_time;
  long microsec;
  struct timeval tv;
  int multi_address;
  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, popen_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 */
  asprintf (&command_line, "%s %s %s", NSLOOKUP_COMMAND, 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 = (char *)_("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]);

    if (strstr (chld_out.line[i], ".in-addr.arpa")) {
      if ((temp_buffer = strstr (chld_out.line[i], "name = ")))
        addresses[n_addresses++] = strdup (temp_buffer + 7);
      else {
        msg = (char *)_("Warning plugin error");
        result = STATE_WARNING;
      }
    }

    /* the server is responding, we just got the host name... */
    if (strstr (chld_out.line[i], "Name:"))
      parse_address = TRUE;
    else if (parse_address == TRUE && (strstr (chld_out.line[i], "Address:") ||
             strstr (chld_out.line[i], "Addresses:"))) {
      temp_buffer = index (chld_out.line[i], ':');
      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,
             _("DNS CRITICAL - '%s' returned empty host name string\n"),
             NSLOOKUP_COMMAND);
      }

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


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

  /* 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(input_buffer, ':');
      if(msg) msg++;
    }
  }

  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,
         _("DNS CRITICAL - '%s' msg parsing exited with no address\n"),
         NSLOOKUP_COMMAND);

  /* 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 (strcmp(address, expected_address[i]) == 0) result = STATE_OK;
      asprintf(&temp_buffer, "%s%s; ", temp_buffer, expected_address[i]);
    }
    if (result == STATE_CRITICAL) {
      /* Strip off last semicolon... */
      temp_buffer[strlen(temp_buffer)-2] = '\0';
      asprintf(&msg, _("expected '%s' but got '%s'"), temp_buffer, address);
    }
  }

  /* check if authoritative */
  if (result == STATE_OK && expect_authority && non_authoritative) {
    result = STATE_CRITICAL;
    asprintf(&msg, _("server %s is not authoritative for %s"), dns_server, query_address);
  }

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

  if (result == STATE_OK) {
    if (strchr (address, ',') == NULL)
      multi_address = FALSE;
    else
      multi_address = TRUE;

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

  return result;
}

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void print_help ( void  )
void print_usage ( void  )

Definition at line 389 of file check_cpqarray.c.

{
  printf("cpqarrayd [options]\n");
  printf("   -h         prints this text\n");
  printf("   -d         enables debugging\n");
}
int process_arguments ( int  argc,
char **  argv 
)
static int qstrcmp ( const void *  p1,
const void *  p2 
) [static]

Definition at line 60 of file check_dns.c.

{
       /* 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);
}

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int validate_arguments ( void  )

Variable Documentation

const char* copyright = "2000-2008"

Definition at line 33 of file check_dns.c.

Definition at line 50 of file check_dns.c.

const char* email = "nagiosplug-devel@lists.sourceforge.net"

Definition at line 34 of file check_dns.c.

Definition at line 56 of file check_dns.c.

Definition at line 53 of file check_dns.c.

Definition at line 54 of file check_dns.c.

const char* progname = "check_dns"

Definition at line 32 of file check_dns.c.

Definition at line 51 of file check_dns.c.

Definition at line 49 of file check_dns.c.

Definition at line 57 of file check_dns.c.

int verbose = FALSE

Definition at line 52 of file check_dns.c.