Set additional header in DNS message explicitly

Some DNS Queries include an optional RR in the additional record section of
DNS, so simply copying the non-zero DNS Header for the additional records, but
not adding any leads to broken DNS packages.

This patch explicitly sets the additional records entry in the DNS header to 0.

Closes #114
Submitted-at: #115
Signed-off-by: Sven Haardiek <sven.haardiek@uni-muenster.de>
Signed-off-by: Numan Siddique <numans@ovn.org>

AUTHORS.rst

@@ -365,6 +365,7 @@ Steve Ruan                         ruansx@cn.ibm.com
 Stuart Cardall                     developer@it-offshore.co.uk
 Sugesh Chandran                    sugesh.chandran@intel.com
 SUGYO Kazushi                      sugyo.org@gmail.com
+Sven Haardiek                      sven.haardiek@uni-muenster.de
 Tadaaki Nagao                      nagao@stratosphere.co.jp
 Terry Wilson                       twilson@redhat.com
 Tetsuo NAKAGAWA                    nakagawa@mxc.nes.nec.co.jp

controller/pinctrl.c

@@ -3023,8 +3023,9 @@ pinctrl_handle_dns_lookup(
     /* Set the response bit to 1 in the flags. */
     out_dns_header->lo_flag |= 0x80;
 
-    /* Set the answer RR. */
+    /* Set the answer RRs. */
     out_dns_header->ancount = htons(ancount);
+    out_dns_header->arcount = 0;
 
     /* Copy the Query section. */
     dp_packet_put(&pkt_out, dp_packet_data(pkt_in), dp_packet_size(pkt_in));