dns plugin: Implement the `SelectNumericQueryTypes' option.

I've added this patch to my collectd because I have my data dir overpopulated
by unknown query types (those not found in nameserv.h which are converted to
their #xxxx numeric form).

When enabled in configuration file, this option just prevent registering these
qtypes to the list.

I don't see any issues, so I decided to contribute this patch to the list.

This has being tested against 4.6.2, but shouldn't have problems with 4.7.0

Your comments are welcome.

Mirko

Signed-off-by: Florian Forster <octo@huhu.verplant.org>

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index ec5010f..a279d0b 100644 (file)
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -921,6 +921,10 @@ may not work on certain platforms, such as MacE<nbsp>OSE<nbsp>X.
 
 Ignore packets that originate from this address.
 
+=item B<SelectNumericQueryTypes> B<true>|B<false>
+
+Enabled by default, collects unknown (and thus presented as numeric only) query types.
+
 =back
 
 =head2 Plugin C<email>

diff --git a/src/dns.c b/src/dns.c
index 8339377..bf341a7 100644 (file)
--- a/src/dns.c
+++ b/src/dns.c
@@ -49,9 +49,10 @@ static const char *config_keys[] =
 {
        "Interface",
        "IgnoreSource",
-       NULL
+       "SelectNumericQueryTypes"
 };
-static int config_keys_num = 2;
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
+static int select_numeric_qtype = 1;
 
 #define PCAP_SNAPLEN 1460
 static char   *pcap_device = NULL;
@@ -158,6 +159,13 @@ static int dns_config (const char *key, const char *value)
                if (value != NULL)
                        ignore_list_add_name (value);
        }
+       else if (strcasecmp (key, "SelectNumericQueryTypes") == 0)
+       {
+               if ((value != NULL) && IS_FALSE (value))
+                       select_numeric_qtype = 0;
+               else
+                       select_numeric_qtype = 1;
+       }
        else
        {
                return (-1);
@@ -171,13 +179,24 @@ static void dns_child_callback (const rfc1035_header_t *dns)
        if (dns->qr == 0)
        {
                /* This is a query */
+               int skip = 0;
+               if (!select_numeric_qtype)
+               {
+                       char *str = qtype_str(dns->qtype);
+                       if ((str == NULL) || (str[0] == '#'))
+                               skip = 1;
+               }
+
                pthread_mutex_lock (&traffic_mutex);
                tr_queries += dns->length;
                pthread_mutex_unlock (&traffic_mutex);
 
-               pthread_mutex_lock (&qtype_mutex);
-               counter_list_add (&qtype_list,  dns->qtype,  1);
-               pthread_mutex_unlock (&qtype_mutex);
+               if (skip == 0)
+               {
+                       pthread_mutex_lock (&qtype_mutex);
+                       counter_list_add (&qtype_list, dns->qtype,  1);
+                       pthread_mutex_unlock (&qtype_mutex);
+               }
        }
        else
        {