[2414] Removed hardcoded DNS_SERVERS option

DNS_SERVERS option is now sent only if requested by clients
 (as it should be)

src/bin/dhcp6/dhcp6_srv.cc

@@ -49,8 +49,6 @@ using namespace isc::util;
 using namespace std;
 using namespace boost;
 
-const std::string HARDCODED_DNS_SERVER = "2001:db8:1::1";
-
 Dhcpv6Srv::Dhcpv6Srv(uint16_t port) {
 
     LOG_DEBUG(dhcp6_logger, DBG_DHCP6_START, DHCP6_OPEN_SOCKET).arg(port);
@@ -322,18 +320,7 @@ void Dhcpv6Srv::appendDefaultOptions(const Pkt6Ptr& question, Pkt6Ptr& answer) {
             .arg(question->getRemoteAddr().toText());
         return;
     }
-    // Add DNS_SERVERS option. It should have been configured.
-    const Subnet::OptionContainer& options = subnet->getOptions();
-    const Subnet::OptionContainerTypeIndex& idx = options.get<1>();
-    const Subnet::OptionContainerTypeRange range =
-        idx.equal_range(D6O_NAME_SERVERS);
-    // In theory we may have multiple options with the same
-    // option code. They are not differentiated right now
-    // until support for option spaces is implemented.
-    // Until that's the case, simply add the first found option.
-    if (std::distance(range.first, range.second) > 0) {
-        answer->addOption(range.first->option);
-    }
+
 }
 
 void Dhcpv6Srv::appendRequestedOptions(const Pkt6Ptr& question, Pkt6Ptr& answer) {
@@ -345,11 +332,6 @@ void Dhcpv6Srv::appendRequestedOptions(const Pkt6Ptr& question, Pkt6Ptr& answer)
         return;
     }
 
-    // Add dns-servers option.
-    OptionPtr dnsservers(new Option6AddrLst(D6O_NAME_SERVERS,
-                                            IOAddress(HARDCODED_DNS_SERVER)));
-    answer->addOption(dnsservers);
-
     // Client requests some options using ORO option. Try to
     // get this option from client's message.
     boost::shared_ptr<Option6IntArray<uint16_t> > option_oro =

src/bin/dhcp6/tests/dhcp6_srv_unittest.cc

@@ -344,13 +344,16 @@ TEST_F(Dhcpv6SrvTest, advertiseOptions) {
     // We have not requested option with code 1000 so it should not
     // be included in the response.
     ASSERT_FALSE(adv->getOption(1000));
+    ASSERT_FALSE(adv->getOption(D6O_NAME_SERVERS));
 
     // Let's now request option with code 1000.
     // We expect that server will include this option in its reply.
     boost::shared_ptr<Option6IntArray<uint16_t> >
         option_oro(new Option6IntArray<uint16_t>(D6O_ORO));
-    // Create vector with one code equal to 1000.
-    std::vector<uint16_t> codes(1, 1000);
+    // Create vector with two option codes.
+    std::vector<uint16_t> codes(2);
+    codes[0] = 1000;
+    codes[1] = D6O_NAME_SERVERS;
     // Pass this code to option.
     option_oro->setValues(codes);
     // Append ORO to SOLICIT message.
@@ -407,7 +410,7 @@ TEST_F(Dhcpv6SrvTest, advertiseOptions) {
 // - copy of client-id
 // - server-id
 // - IA that includes IAADDR
-TEST_F(Dhcpv6SrvTest, SolicitBasic2) {
+TEST_F(Dhcpv6SrvTest, SolicitBasic) {
     boost::scoped_ptr<NakedDhcpv6Srv> srv;
     ASSERT_NO_THROW( srv.reset(new NakedDhcpv6Srv(0)) );