<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <style>  </style> </head> <body lang=EN-AU link=blue vlink=purple> <div class=Section1> Hi. I use round-robin settings on my DNS, which renders the “-a” (check address) option useless. This is because you can’t predict the order in which the DNS will respond to your DNS queries.<o:p></o:p> <o:p> </o:p> I’ve patched check_dns.c v 1.4.10 to include a “-o” option, allowing you to sort the DNS response. This way you always know what order the response will come in.<o:p></o:p> <o:p> </o:p> I’m attaching the patched file to this message and pasting the diff on the message, below my sig. Hope it helps other people.<o:p></o:p> <o:p> </o:p> Regards,<o:p></o:p> ________________ Thiago Figueiro Technical Operations Manager Digital Business T +61 9358 7123 F +61 9358 7690 W westfield.com E <a href="mailto:tfigueiro@au.westfield.com">tfigueiro@au.westfield.com</a> <o:p></o:p> <o:p> </o:p> <o:p> </o:p> --- /tmp/nagios-plugins-1.4.10/plugins/check_dns.c Mon Jan 29 08:46:41 2007<o:p></o:p> +++ check_dns.c Mon Nov 26 17:29:59 2007<o:p></o:p> @@ -62,6 +62,9 @@<o:p></o:p> int expect_authority = FALSE;<o:p></o:p> thresholds *time_thresholds = NULL;<o:p></o:p> <o:p> </o:p> +#define IPV4_SIZE 16*sizeof(char)<o:p></o:p> +int order_results = FALSE;<o:p></o:p> +<o:p></o:p> int<o:p></o:p> main (int argc, char **argv)<o:p></o:p> {<o:p></o:p> @@ -178,6 +181,56 @@<o:p></o:p> _("DNS CRITICAL - '%s' msg parsing exited with no address\n"),<o:p></o:p> NSLOOKUP_COMMAND);<o:p></o:p> <o:p> </o:p> + /* Order the results from DNS server */<o:p></o:p> + if (order_results) {<o:p></o:p> + int num_result = 1; /* No commas? only one address */<o:p></o:p> + int i = 0;<o:p></o:p> + char *ipv4_sort = NULL;<o:p></o:p> + char *pstrtmp;<o:p></o:p> + char *pstrtok;<o:p></o:p> +<o:p></o:p> + pstrtmp = strchr(address, ',');<o:p></o:p> + while (pstrtmp) {<o:p></o:p> + num_result++;<o:p></o:p> + pstrtmp += sizeof(char);<o:p></o:p> + pstrtmp = strchr(pstrtmp, ',');<o:p></o:p> + }<o:p></o:p> +<o:p></o:p> + if (num_result > 1) {<o:p></o:p> + ipv4_sort = malloc(IPV4_SIZE*num_result);<o:p></o:p> + if (NULL == ipv4_sort)<o:p></o:p> + die (STATE_UNKNOWN,<o:p></o:p> + _("DNS UNKNOWN - Failed allocating %d bytes for ordering results\n"),<o:p></o:p> + IPV4_SIZE*num_result);<o:p></o:p> +<o:p></o:p> + memset(ipv4_sort, 0, IPV4_SIZE*num_result);<o:p></o:p> + pstrtmp = strdup(address);<o:p></o:p> + pstrtok = strtok(pstrtmp, ",");<o:p></o:p> + i = 0;<o:p></o:p> + while (pstrtok) {<o:p></o:p> + strncpy(ipv4_sort+(i*IPV4_SIZE), pstrtok, IPV4_SIZE);<o:p></o:p> + pstrtok = strtok(NULL, ",");<o:p></o:p> + i++;<o:p></o:p> + }<o:p></o:p> + free(pstrtmp);<o:p></o:p> +<o:p></o:p> + qsort(ipv4_sort, num_result, IPV4_SIZE, strcmp);<o:p></o:p> +<o:p></o:p> + pstrtmp = address;<o:p></o:p> + for (i = 0; i < num_result; i++) {<o:p></o:p> + strcpy(pstrtmp, ipv4_sort+(i*IPV4_SIZE));<o:p></o:p> + pstrtmp += (strlen(pstrtmp));<o:p></o:p> + if (i+1 < num_result) {<o:p></o:p> + *pstrtmp = ',';<o:p></o:p> + pstrtmp += sizeof(char);<o:p></o:p> + }<o:p></o:p> + *pstrtmp = '\0';<o:p></o:p> + }<o:p></o:p> +<o:p></o:p> + free(ipv4_sort);<o:p></o:p> + }<o:p></o:p> + }<o:p></o:p> +<o:p></o:p> /* compare to expected address */<o:p></o:p> if (result == STATE_OK && match_expected_address && strcmp(address, expected_address)) {<o:p></o:p> result = STATE_CRITICAL;<o:p></o:p> @@ -316,7 +369,7 @@<o:p></o:p> strcpy (argv[c], "-t");<o:p></o:p> <o:p> </o:p> while (1) {<o:p></o:p> - c = getopt_long (argc, argv, "hVvAt:H:s:r:a:w:c:", long_opts, &opt_index);<o:p></o:p> + c = getopt_long (argc, argv, "hVvAot:H:s:r:a:w:c:", long_opts, &opt_index);<o:p></o:p> <o:p> </o:p> if (c == -1 || c == EOF)<o:p></o:p> break;<o:p></o:p> @@ -331,6 +384,9 @@<o:p></o:p> case 'v': /* version */<o:p></o:p> verbose = TRUE;<o:p></o:p> break;<o:p></o:p> + case 'o':<o:p></o:p> + order_results = TRUE;<o:p></o:p> + break;<o:p></o:p> case 't': /* timeout period */<o:p></o:p> timeout_interval = atoi (optarg);<o:p></o:p> break;<o:p></o:p> @@ -431,6 +487,8 @@<o:p></o:p> printf (" %s\n", _("Optional IP-ADDRESS you expect the DNS server to return. HOST must end with ."));<o:p></o:p> printf (" -A, --expect-authority\n");<o:p></o:p> printf (" %s\n", _("Optionally expect the DNS server to be authoritative for the lookup"));<o:p></o:p> + printf (" -o\n");<o:p></o:p> + printf (" %s\n", _("Order the results from DNS server. Useful for round-robind setups."));<o:p></o:p> printf (" -w, --warning=seconds\n");<o:p></o:p> printf (" %s\n", _("Return warning if elapsed time exceeds value. Default off"));<o:p></o:p> printf (" -c, --critical=seconds\n");<o:p></o:p> <o:p> </o:p> </div> ______________________________________________________ CONFIDENTIALITY NOTICE This electronic mail message, including any and/or all attachments, is for the sole use of the intended recipient(s), and may contain confidential and/or privileged information, pertaining to business conducted under the direction and supervision of the sending organization. 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