Adding labellen indexer which counts the number of labels in a DNS me…

…ssage

src/Makefile.am

@@ -23,7 +23,7 @@ dsc_SOURCES = asn_index.c certain_qnames_index.c client_index.c \
   idn_qname_index.c inX_addr.c ip_direction_index.c ip_proto_index.c \
   ip_version_index.c md_array.c md_array_json_printer.c \
   md_array_xml_printer.c msglen_index.c null_index.c opcode_index.c \
-  parse_conf.c pcap.c qclass_index.c qname_index.c qnamelen_index.c \
+  parse_conf.c pcap.c qclass_index.c qname_index.c qnamelen_index.c labellen_index.c \
   qr_aa_bits_index.c qtype_index.c query_classification_index.c rcode_index.c \
   rd_bit_index.c server_ip_addr_index.c tc_bit_index.c tld_index.c \
   transport_index.c xmalloc.c response_time_index.c tld_list.c \
@@ -37,7 +37,7 @@ dist_dsc_SOURCES = asn_index.h base64.h certain_qnames_index.h client_index.h \
   do_bit_index.h edns_bufsiz_index.h edns_version_index.h geoip.h hashtbl.h \
   idn_qname_index.h inX_addr.h ip_direction_index.h ip_proto_index.h \
   ip_version_index.h md_array.h msglen_index.h null_index.h opcode_index.h \
-  parse_conf.h pcap.h qclass_index.h qname_index.h qnamelen_index.h \
+  parse_conf.h pcap.h qclass_index.h qname_index.h qnamelen_index.h labellen_index.h \
   qr_aa_bits_index.h qtype_index.h query_classification_index.h rcode_index.h \
   rd_bit_index.h server_ip_addr_index.h syslog_debug.h tc_bit_index.h \
   tld_index.h transport_index.h xmalloc.h response_time_index.h tld_list.h \

src/dns_message.c

@@ -52,6 +52,7 @@
 #include "client_subnet_index.h"
 #include "server_ip_addr_index.h"
 #include "qnamelen_index.h"
+#include "labellen_index.h"
 #include "qname_index.h"
 #include "msglen_index.h"
 #include "certain_qnames_index.h"
@@ -91,6 +92,7 @@ static indexer indexers[] = {
     { "null", 0, null_indexer, null_iterator },
     { "qclass", 0, qclass_indexer, qclass_iterator, qclass_reset },
     { "qnamelen", 0, qnamelen_indexer, qnamelen_iterator, qnamelen_reset },
+    { "labellen", 0, labellen_indexer, labellen_iterator, labellen_reset },
     { "qname", 0, qname_indexer, qname_iterator, qname_reset },
     { "second_ld", 0, second_ld_indexer, second_ld_iterator, second_ld_reset },
     { "third_ld", 0, third_ld_indexer, third_ld_iterator, third_ld_reset },

src/dsc.conf.5.in

@@ -535,6 +535,12 @@ section.
 Note this is the \*(lqexpanded\*(rq length if the message happens to take
 advantage of DNS message \*(lqcompression\*(rq.
 .TP
+\fBlabellen\fR
+The count of labels the first (and usually only) QNAME in a DNS message question
+section.
+Note this count is based on the full QNAME if the message happens to take
+advantage of DNS message \*(lqcompression\*(rq.
+.TP
 \fBqtype\fR
 The query type (QTYPE) for the first QNAME in the DNS message question
 section.

src/labellen_index.c

@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2008-2022, OARC, Inc.
+ * Copyright (c) 2007-2008, Internet Systems Consortium, Inc.
+ * Copyright (c) 2003-2007, The Measurement Factory, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+
+#include "labellen_index.h"
+
+#include <string.h>
+
+static int largest = 0;
+
+#define MAX_LABELS 64
+
+int labellen_indexer(const dns_message* m)
+{
+    if (m->malformed)
+        return -1;
+
+    int i, count = 1;
+    int len = strlen(m->qname);
+    if (len == 0 || (len == 1 && m->qname[0] == '.')) {
+        count = 0;
+    } else {
+        for (i = 0; i < len; i++)
+            if (m->qname[i] == '.')
+                count++;
+    }
+    if (count >= MAX_LABELS)
+        count = MAX_LABELS - 1;
+    if (count > largest)
+        largest = count;
+    return count;
+}
+
+static int next_iter;
+
+int labellen_iterator(const char** label)
+{
+    static char label_buf[10];
+    if (NULL == label) {
+        next_iter = 0;
+        return largest + 1;
+    }
+    if (next_iter > largest)
+        return -1;
+    snprintf(label_buf, sizeof(label_buf), "%d", next_iter);
+    *label = label_buf;
+    return next_iter++;
+}
+
+void labellen_reset()
+{
+    largest = 0;
+}

src/labellen_index.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2008-2022, OARC, Inc.
+ * Copyright (c) 2007-2008, Internet Systems Consortium, Inc.
+ * Copyright (c) 2003-2007, The Measurement Factory, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __dsc_labellen_index_h
+#define __dsc_labellen_index_h
+
+#include "dns_message.h"
+
+int  labellen_indexer(const dns_message*);
+int  labellen_iterator(const char** label);
+void labellen_reset(void);
+
+#endif /* __dsc_labellen_index_h */