[master] Merged trac4106_update (DHCP4o6 IPC)

src/bin/dhcp4/Makefile.am

@@ -62,7 +62,7 @@ libdhcp4_la_SOURCES += ctrl_dhcp4_srv.cc ctrl_dhcp4_srv.h
 libdhcp4_la_SOURCES += json_config_parser.cc json_config_parser.h
 libdhcp4_la_SOURCES += dhcp4_log.cc dhcp4_log.h
 libdhcp4_la_SOURCES += dhcp4_srv.cc dhcp4_srv.h
-libdhcp4_la_SOURCES += dhcp4_dhcp4o6_ipc.cc dhcp4_dhcp4o6_ipc.h
+libdhcp4_la_SOURCES += dhcp4to6_ipc.cc dhcp4to6_ipc.h
 
 libdhcp4_la_SOURCES += kea_controller.cc
 

src/bin/dhcp4/ctrl_dhcp4_srv.cc

@@ -8,7 +8,7 @@
 #include <cc/data.h>
 #include <dhcp4/ctrl_dhcp4_srv.h>
 #include <dhcp4/dhcp4_log.h>
-#include <dhcp4/dhcp4_dhcp4o6_ipc.h>
+#include <dhcp4/dhcp4to6_ipc.h>
 #include <hooks/hooks_manager.h>
 #include <dhcp4/json_config_parser.h>
 #include <dhcpsrv/cfgmgr.h>
@@ -192,7 +192,7 @@ ControlledDhcpv4Srv::processConfig(isc::data::ConstElementPtr config) {
 
     // Setup DHCPv4-over-DHCPv6 IPC
     try {
-        Dhcp4o6Ipc::instance().open();
+        Dhcp4to6Ipc::instance().open();
     } catch (const std::exception& ex) {
         std::ostringstream err;
         err << "error starting DHCPv4-over-DHCPv6 IPC "

src/bin/dhcp4/dhcp4_dhcp4o6_ipc.cc

@@ -1,75 +0,0 @@
-// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
-//
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
-
-#include <config.h>
-
-#include <util/buffer.h>
-#include <dhcp/iface_mgr.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <dhcp4/dhcp4_dhcp4o6_ipc.h>
-
-using namespace std;
-
-namespace isc {
-namespace dhcp {
-
-Dhcp4o6Ipc::Dhcp4o6Ipc() : Dhcp4o6IpcBase() {}
-
-Dhcp4o6Ipc& Dhcp4o6Ipc::instance() {
-    static Dhcp4o6Ipc dhcp4o6_ipc;
-    return (dhcp4o6_ipc);
-}
-
-void Dhcp4o6Ipc::open() {
-    uint32_t port = CfgMgr::instance().getStagingCfg()->getDhcp4o6Port();
-    if (port == 0) {
-        Dhcp4o6IpcBase::close();
-        return;
-    }
-    if (port > 65534) {
-        isc_throw(OutOfRange, "DHCP4o6 port " << port);
-    }
-
-    int old_fd = socket_fd_;
-    socket_fd_ = Dhcp4o6IpcBase::open(static_cast<uint16_t>(port), 4);
-    if ((old_fd == -1) && (socket_fd_ != old_fd)) {
-        IfaceMgr::instance().addExternalSocket(socket_fd_, Dhcp4o6Ipc::handler);
-    }
-}
-
-void Dhcp4o6Ipc::handler() {
-    Dhcp4o6Ipc& ipc = Dhcp4o6Ipc::instance();
-    Pkt6Ptr pkt = ipc.receive();
-    if (!pkt) {
-        return;
-    }
-
-    OptionCollection msgs = pkt->getOptions(D6O_DHCPV4_MSG);
-    if (msgs.size() != 1) {
-        return;
-    }
-    OptionPtr msg = pkt->getOption(D6O_DHCPV4_MSG);
-    if (!msg) {
-        isc_throw(Unexpected, "Can't get DHCPv4 message option");
-    }
-    instance().received_.reset(new Pkt4o6(msg->getData(), pkt));
-}
-
-Pkt4o6Ptr& Dhcp4o6Ipc::getReceived() {
-    return (received_);
-}
-
-};  // namespace dhcp
-
-};  // namespace isc

src/bin/dhcp4/dhcp4to6_ipc.cc

@@ -0,0 +1,84 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <util/buffer.h>
+#include <dhcp/iface_mgr.h>
+#include <dhcpsrv/cfgmgr.h>
+#include <dhcp4/dhcp4to6_ipc.h>
+
+using namespace std;
+
+namespace isc {
+namespace dhcp {
+
+Dhcp4to6Ipc::Dhcp4to6Ipc() : Dhcp4o6IpcBase() {}
+
+Dhcp4to6Ipc& Dhcp4to6Ipc::instance() {
+    static Dhcp4to6Ipc dhcp4to6_ipc;
+    return (dhcp4to6_ipc);
+}
+
+void Dhcp4to6Ipc::open() {
+    uint32_t port = CfgMgr::instance().getStagingCfg()->getDhcp4o6Port();
+    if (port == 0) {
+        Dhcp4o6IpcBase::close();
+        return;
+    }
+    if (port > 65534) {
+        isc_throw(OutOfRange, "DHCP4o6 port " << port);
+    }
+
+    int old_fd = socket_fd_;
+    socket_fd_ = Dhcp4o6IpcBase::open(static_cast<uint16_t>(port),
+                                      ENDPOINT_TYPE_V4);
+    if ((old_fd == -1) && (socket_fd_ != old_fd)) {
+        IfaceMgr::instance().addExternalSocket(socket_fd_,
+                                               Dhcp4to6Ipc::handler);
+    }
+}
+
+void Dhcp4to6Ipc::handler() {
+    Dhcp4to6Ipc& ipc = Dhcp4to6Ipc::instance();
+
+    // Reset received message in case we return from this method before the
+    // received message pointer is updated.
+    ipc.received_.reset();
+
+    // Receive message from the IPC socket.
+    Pkt6Ptr pkt = ipc.receive();
+    if (!pkt) {
+        return;
+    }
+
+    // Each message must contain option holding DHCPv4 message.
+    OptionCollection msgs = pkt->getOptions(D6O_DHCPV4_MSG);
+    if (msgs.empty()) {
+        isc_throw(Dhcp4o6IpcError, "DHCPv4 message option not present in the"
+                  " DHCPv4o6 message received by the DHCPv4 server");
+    } else if (msgs.size() > 1) {
+        isc_throw(Dhcp4o6IpcError, "expected exactly one DHCPv4 message within"
+                  " DHCPv4 message option received by the DHCPv4 server");
+    }
+
+    OptionPtr msg = msgs.begin()->second;
+    if (!msg) {
+        isc_throw(Dhcp4o6IpcError, "null DHCPv4 message option in the"
+                  " DHCPv4o6 message received by the DHCPv4 server");
+    }
+
+    // Record this message.
+    ipc.received_.reset(new Pkt4o6(msg->getData(), pkt));
+}
+
+Pkt4o6Ptr& Dhcp4to6Ipc::getReceived() {
+    return (received_);
+}
+
+};  // namespace dhcp
+
+};  // namespace isc

src/bin/dhcp4/dhcp4_dhcp4o6_ipc.h

@@ -1,21 +1,13 @@
 // Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
 //
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-#ifndef DHCP4_DHCP4O6_IPC_H
-#define DHCP4_DHCP4O6_IPC_H
+#ifndef DHCP4TO6_IPC_H
+#define DHCP4TO6_IPC_H
 
-/// @file dhcp4_dhcp4o6_ipc.h Defines the Dhcp4o6Ipc class.
+/// @file dhcp4to6_ipc.h Defines the Dhcp4o6Ipc class.
 /// This file defines the class Kea uses to act as the DHCPv4 server
 /// side of DHCPv4-over-DHCPv6 communication between servers.
 ///
@@ -28,23 +20,23 @@ namespace isc {
 namespace dhcp {
 
 /// @brief Handles DHCPv4-over-DHCPv6 IPC on the DHCPv4 server side
-class Dhcp4o6Ipc : public Dhcp4o6IpcBase {
+class Dhcp4to6Ipc : public Dhcp4o6IpcBase {
 protected:
     /// @brief Constructor
     ///
     /// Default constructor
-    Dhcp4o6Ipc();
+    Dhcp4to6Ipc();
 
     /// @brief Destructor.
-    virtual ~Dhcp4o6Ipc() { }
+    virtual ~Dhcp4to6Ipc() { }
 
 public:
-    /// @brief Returns pointer to the sole instance of Dhcp4o6Ipc
+    /// @brief Returns pointer to the sole instance of Dhcp4to6Ipc
     ///
-    /// Dhcp4o6Ipc is a singleton class
+    /// Dhcp4to6Ipc is a singleton class
     ///
     /// @return the only existing instance of DHCP4o6 IPC
-    static Dhcp4o6Ipc& instance();
+    static Dhcp4to6Ipc& instance();
 
     /// @brief Open communication socket
     ///

src/bin/dhcp4/tests/Makefile.am

@@ -94,6 +94,7 @@ dhcp4_unittests_SOURCES += release_unittest.cc
 dhcp4_unittests_SOURCES += out_of_range_unittest.cc
 dhcp4_unittests_SOURCES += decline_unittest.cc
 dhcp4_unittests_SOURCES += kea_controller_unittest.cc
+dhcp4_unittests_SOURCES += dhcp4to6_ipc_unittest.cc
 
 nodist_dhcp4_unittests_SOURCES = marker_file.h test_libraries.h
 

src/bin/dhcp4/tests/dhcp4to6_ipc_unittest.cc

@@ -0,0 +1,176 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+#include <asiolink/io_address.h>
+#include <dhcp/pkt4o6.h>
+#include <dhcp/pkt6.h>
+#include <dhcp/tests/iface_mgr_test_config.h>
+#include <dhcp4/dhcp4to6_ipc.h>
+#include <dhcpsrv/cfgmgr.h>
+#include <dhcpsrv/testutils/dhcp4o6_test_ipc.h>
+#include <gtest/gtest.h>
+#include <stdint.h>
+
+using namespace isc;
+using namespace isc::asiolink;
+using namespace isc::dhcp;
+using namespace isc::dhcp::test;
+using namespace isc::util;
+
+namespace {
+
+/// @brief Port number used in tests.
+const uint16_t TEST_PORT = 32000;
+
+/// @brief Define short name for the test IPC.
+typedef Dhcp4o6TestIpc TestIpc;
+
+/// @brief Test fixture class for DHCPv4 endpoint of DHCPv4o6 IPC.
+class Dhcp4to6IpcTest : public ::testing::Test {
+public:
+
+    /// @brief Constructor
+    ///
+    /// Configures IPC to use a test port. It also provides a fake
+    /// configuration of interfaces.
+    Dhcp4to6IpcTest()
+        : iface_mgr_test_config_(true) {
+        configurePort(TEST_PORT);
+    }
+
+    /// @brief Configure DHCP4o6 port.
+    ///
+    /// @param port New port.
+    void configurePort(uint16_t port);
+
+    /// @brief Creates an instance of the DHCPv4o6 Message option.
+    ///
+    /// The option will contain an empty DHCPREQUEST message, with
+    /// just the Message Type option inside and nothing else.
+    ///
+    /// @return Pointer to the instance of the DHCPv4-query Message option.
+    OptionPtr createDHCPv4MsgOption() const;
+
+private:
+
+    /// @brief Provides fake configuration of interfaces.
+    IfaceMgrTestConfig iface_mgr_test_config_;
+
+};
+
+void
+Dhcp4to6IpcTest::configurePort(uint16_t port) {
+    CfgMgr::instance().getStagingCfg()->setDhcp4o6Port(port);
+}
+
+OptionPtr
+Dhcp4to6IpcTest::createDHCPv4MsgOption() const {
+    // Create the DHCPv4 message.
+    Pkt4Ptr pkt(new Pkt4(DHCPREQUEST, 1234));
+    // Make a wire representation of the DHCPv4 message.
+    pkt->pack();
+    OutputBuffer& output_buffer = pkt->getBuffer();
+    const uint8_t* data = static_cast<const uint8_t*>(output_buffer.getData());
+    OptionBuffer option_buffer(data, data + output_buffer.getLength());
+
+    // Create the DHCPv4 Message option holding the created message.
+    OptionPtr opt_msg(new Option(Option::V6, D6O_DHCPV4_MSG, option_buffer));
+    return (opt_msg);
+}
+
+// This test verifies that the IPC returns an error when trying to bind
+// to the out of range port.
+TEST_F(Dhcp4to6IpcTest, invalidPortError) {
+    // Create instance of the IPC endpoint under test with out-of-range port.
+    configurePort(65535);
+    Dhcp4to6Ipc& ipc = Dhcp4to6Ipc::instance();
+    EXPECT_THROW(ipc.open(), isc::OutOfRange);
+}
+
+// This test verifies that the DHCPv4 endpoint of the DHCPv4o6 IPC can
+// receive messages.
+TEST_F(Dhcp4to6IpcTest, receive) {
+    // Create instance of the IPC endpoint under test.
+    Dhcp4to6Ipc& ipc = Dhcp4to6Ipc::instance();
+    // Create instance of the IPC endpoint being used as a source of messages.
+    TestIpc src_ipc(TEST_PORT, TestIpc::ENDPOINT_TYPE_V6);
+
+    // Open both endpoints.
+    ASSERT_NO_THROW(ipc.open());
+    ASSERT_NO_THROW(src_ipc.open());
+
+    // Create message to be sent over IPC.
+    Pkt6Ptr pkt(new Pkt6(DHCPV6_DHCPV4_QUERY, 1234));
+    pkt->addOption(createDHCPv4MsgOption());
+    pkt->setIface("eth0");
+    pkt->setRemoteAddr(IOAddress("2001:db8:1::123"));
+    ASSERT_NO_THROW(pkt->pack());
+
+    // Send and wait up to 1 second to receive it.
+    ASSERT_NO_THROW(src_ipc.send(pkt));
+    ASSERT_NO_THROW(IfaceMgr::instance().receive6(1, 0));
+
+    // Make sure that the message has been received.
+    Pkt4o6Ptr pkt_received = ipc.getReceived();
+    ASSERT_TRUE(pkt_received);
+    Pkt6Ptr pkt6_received = pkt_received->getPkt6();
+    ASSERT_TRUE(pkt6_received);
+    EXPECT_EQ("eth0", pkt6_received->getIface());
+    EXPECT_EQ("2001:db8:1::123", pkt6_received->getRemoteAddr().toText());
+}
+
+// This test verifies that message with multiple DHCPv4 query options
+// is rejected.
+TEST_F(Dhcp4to6IpcTest, receiveMultipleQueries) {
+    // Create instance of the IPC endpoint under test.
+    Dhcp4to6Ipc& ipc = Dhcp4to6Ipc::instance();
+    // Create instance of the IPC endpoint being used as a source of messages.
+    TestIpc src_ipc(TEST_PORT, TestIpc::ENDPOINT_TYPE_V6);
+
+    // Open both endpoints.
+    ASSERT_NO_THROW(ipc.open());
+    ASSERT_NO_THROW(src_ipc.open());
+
+    // Create message to be sent over IPC.
+    Pkt6Ptr pkt(new Pkt6(DHCPV6_DHCPV4_QUERY, 1234));
+    // Add two DHCPv4 query options.
+    pkt->addOption(createDHCPv4MsgOption());
+    pkt->addOption(createDHCPv4MsgOption());
+    pkt->setIface("eth0");
+    pkt->setRemoteAddr(IOAddress("2001:db8:1::123"));
+    ASSERT_NO_THROW(pkt->pack());
+
+    // Send message.
+    ASSERT_NO_THROW(src_ipc.send(pkt));
+    // Reception handler should throw exception.
+    EXPECT_THROW(IfaceMgr::instance().receive6(1, 0), Dhcp4o6IpcError);
+}
+
+// This test verifies that message with no DHCPv4 query options is rejected.
+TEST_F(Dhcp4to6IpcTest, receiveNoQueries) {
+    // Create instance of the IPC endpoint under test.
+    Dhcp4to6Ipc& ipc = Dhcp4to6Ipc::instance();
+    // Create instance of the IPC endpoint being used as a source of messages.
+    TestIpc src_ipc(TEST_PORT, TestIpc::ENDPOINT_TYPE_V6);
+
+    // Open both endpoints.
+    ASSERT_NO_THROW(ipc.open());
+    ASSERT_NO_THROW(src_ipc.open());
+
+    // Create message to be sent over IPC without DHCPv4 query option.
+    Pkt6Ptr pkt(new Pkt6(DHCPV6_DHCPV4_QUERY, 1234));
+    pkt->setIface("eth0");
+    pkt->setRemoteAddr(IOAddress("2001:db8:1::123"));
+    ASSERT_NO_THROW(pkt->pack());
+
+    // Send message.
+    ASSERT_NO_THROW(src_ipc.send(pkt));
+    // Reception handler should throw exception.
+    EXPECT_THROW(IfaceMgr::instance().receive6(1, 0), Dhcp4o6IpcError);
+}
+
+} // end of anonymous namespace

src/bin/dhcp6/Makefile.am

@@ -63,7 +63,7 @@ libdhcp6_la_SOURCES += dhcp6_log.cc dhcp6_log.h
 libdhcp6_la_SOURCES += dhcp6_srv.cc dhcp6_srv.h
 libdhcp6_la_SOURCES += ctrl_dhcp6_srv.cc ctrl_dhcp6_srv.h
 libdhcp6_la_SOURCES += json_config_parser.cc json_config_parser.h
-libdhcp6_la_SOURCES += dhcp6_dhcp4o6_ipc.cc dhcp6_dhcp4o6_ipc.h
+libdhcp6_la_SOURCES += dhcp6to4_ipc.cc dhcp6to4_ipc.h
 
 libdhcp6_la_SOURCES += kea_controller.cc
 

src/bin/dhcp6/ctrl_dhcp6_srv.cc

@@ -11,7 +11,7 @@
 #include <dhcpsrv/cfgmgr.h>
 #include <dhcpsrv/cfg_db_access.h>
 #include <dhcp6/ctrl_dhcp6_srv.h>
-#include <dhcp6/dhcp6_dhcp4o6_ipc.h>
+#include <dhcp6/dhcp6to4_ipc.h>
 #include <dhcp6/dhcp6_log.h>
 #include <dhcp6/json_config_parser.h>
 #include <hooks/hooks_manager.h>
@@ -216,7 +216,7 @@ ControlledDhcpv6Srv::processConfig(isc::data::ConstElementPtr config) {
 
     // Setup DHCPv4-over-DHCPv6 IPC
     try {
-        Dhcp4o6Ipc::instance().open();
+        Dhcp6to4Ipc::instance().open();
     } catch (const std::exception& ex) {
         std::ostringstream err;
         err << "error starting DHCPv4-over-DHCPv6 IPC "

src/bin/dhcp6/dhcp6_dhcp4o6_ipc.cc

@@ -1,75 +0,0 @@
-// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
-//
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
-
-#include <config.h>
-
-#include <util/buffer.h>
-#include <dhcp/iface_mgr.h>
-#include <dhcpsrv/cfgmgr.h>
-#include <dhcp6/dhcp6_dhcp4o6_ipc.h>
-
-using namespace std;
-
-namespace isc {
-namespace dhcp {
-
-Dhcp4o6Ipc::Dhcp4o6Ipc() : Dhcp4o6IpcBase() {}
-
-Dhcp4o6Ipc& Dhcp4o6Ipc::instance() {
-    static Dhcp4o6Ipc dhcp4o6_ipc;
-    return (dhcp4o6_ipc);
-}
-
-void Dhcp4o6Ipc::open() {
-    uint32_t port = CfgMgr::instance().getStagingCfg()->getDhcp4o6Port();
-    if (port == 0) {
-        Dhcp4o6IpcBase::close();
-        return;
-    }
-    if (port > 65534) {
-        isc_throw(OutOfRange, "DHCP4o6 port " << port);
-    }
-
-    int old_fd = socket_fd_;
-    socket_fd_ = Dhcp4o6IpcBase::open(static_cast<uint16_t>(port), 6);
-    if ((old_fd == -1) && (socket_fd_ != old_fd)) {
-        IfaceMgr::instance().addExternalSocket(socket_fd_, Dhcp4o6Ipc::handler);
-    }
-}
-
-void Dhcp4o6Ipc::handler() {
-    Dhcp4o6Ipc& ipc = Dhcp4o6Ipc::instance();
-    Pkt6Ptr pkt = ipc.receive();
-    if (!pkt) {
-        return;
-    }
-
-    isc::util::OutputBuffer& buf = pkt->getBuffer();
-    buf.clear();
-    pkt->pack();
-
-    uint8_t msg_type = buf[0];
-    if ((msg_type == DHCPV6_RELAY_FORW) || (msg_type == DHCPV6_RELAY_REPL)) {
-        pkt->setRemotePort(DHCP6_SERVER_PORT);
-    } else {
-        pkt->setRemotePort(DHCP6_CLIENT_PORT);
-    }
-
-    IfaceMgr::instance().send(pkt);
-    // processStatsSent(pkt);
-}
-
-};  // namespace dhcp
-
-};  // namespace isc

src/bin/dhcp6/dhcp6_dhcp4o6_ipc.h

@@ -1,61 +0,0 @@
-// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
-//
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
-
-#ifndef DHCP6_DHCP4O6_IPC_H
-#define DHCP6_DHCP4O6_IPC_H
-
-/// @file dhcp6_dhcp4o6_ipc.h Defines the Dhcp4o6Ipc class.
-/// This file defines the class Kea uses to act as the DHCPv6 server
-/// side of DHCPv4-over-DHCPv6 communication between servers.
-///
-#include <dhcpsrv/dhcp4o6_ipc.h>
-#include <boost/shared_ptr.hpp>
-
-namespace isc {
-namespace dhcp {
-
-/// @brief Handles DHCPv4-over-DHCPv6 IPC on the DHCPv6 server side
-class Dhcp4o6Ipc : public Dhcp4o6IpcBase {
-protected:
-    /// @brief Constructor
-    ///
-    /// Default constructor
-    Dhcp4o6Ipc();
-
-    /// @brief Destructor.
-    virtual ~Dhcp4o6Ipc() { }
-
-public:
-    /// @brief Returns pointer to the sole instance of Dhcp4o6Ipc
-    ///
-    /// Dhcp4o6Ipc is a singleton class
-    ///
-    /// @return the only existing instance of DHCP4o6 IPC
-    static Dhcp4o6Ipc& instance();
-
-    /// @brief Open communication socket
-    ///
-    /// Call base open method and sets the handler/callback when needed
-    virtual void open();
-
-    /// @brief On receive handler
-    ///
-    /// The handler sends the DHCPv6 packet back to the remote address
-    static void handler();
-};
-
-} // namespace isc
-} // namespace dhcp
-
-#endif

src/bin/dhcp6/dhcp6_srv.cc

@@ -25,7 +25,7 @@
 #include <dhcp/option_vendor_class.h>
 #include <dhcp/option_int_array.h>
 #include <dhcp/pkt6.h>
-#include <dhcp6/dhcp6_dhcp4o6_ipc.h>
+#include <dhcp6/dhcp6to4_ipc.h>
 #include <dhcp6/dhcp6_log.h>
 #include <dhcp6/dhcp6_srv.h>
 #include <dhcpsrv/callout_handle_store.h>
@@ -213,7 +213,7 @@ Dhcpv6Srv::~Dhcpv6Srv() {
     }
 
     try {
-        Dhcp4o6Ipc::instance().close();
+        Dhcp6to4Ipc::instance().close();
     } catch(const std::exception& ex) {
         // Highly unlikely, but lets Report it but go on
         // LOG_ERROR(dhcp6_logger, DHCP6_SRV_DHCP4O6_ERROR).arg(ex.what());

src/bin/dhcp6/dhcp6to4_ipc.cc

@@ -0,0 +1,75 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <util/buffer.h>
+#include <dhcp/iface_mgr.h>
+#include <dhcpsrv/cfgmgr.h>
+#include <dhcp6/dhcp6to4_ipc.h>
+
+using namespace std;
+
+namespace isc {
+namespace dhcp {
+
+Dhcp6to4Ipc::Dhcp6to4Ipc() : Dhcp4o6IpcBase() {}
+
+Dhcp6to4Ipc& Dhcp6to4Ipc::instance() {
+    static Dhcp6to4Ipc dhcp6to4_ipc;
+    return (dhcp6to4_ipc);
+}
+
+void Dhcp6to4Ipc::open() {
+    uint32_t port = CfgMgr::instance().getStagingCfg()->getDhcp4o6Port();
+    if (port == 0) {
+        Dhcp4o6IpcBase::close();
+        return;
+    }
+    if (port > 65534) {
+        isc_throw(OutOfRange, "DHCP4o6 port " << port);
+    }
+
+    int old_fd = socket_fd_;
+    socket_fd_ = Dhcp4o6IpcBase::open(static_cast<uint16_t>(port),
+                                      ENDPOINT_TYPE_V6);
+    if ((old_fd == -1) && (socket_fd_ != old_fd)) {
+        IfaceMgr::instance().addExternalSocket(socket_fd_,
+                                               Dhcp6to4Ipc::handler);
+    }
+}
+
+void Dhcp6to4Ipc::handler() {
+    Dhcp6to4Ipc& ipc = Dhcp6to4Ipc::instance();
+
+    // Receive message from IPC.
+    Pkt6Ptr pkt = ipc.receive();
+    if (!pkt) {
+        return;
+    }
+
+    // The received message has been unpacked by the receive() function. This
+    // method could have modified the message so it's better to pack() it
+    // again because we'll be forwarding it to a client.
+    isc::util::OutputBuffer& buf = pkt->getBuffer();
+    buf.clear();
+    pkt->pack();
+
+    uint8_t msg_type = pkt->getType();
+    if ((msg_type == DHCPV6_RELAY_FORW) || (msg_type == DHCPV6_RELAY_REPL)) {
+        pkt->setRemotePort(DHCP6_SERVER_PORT);
+    } else {
+        pkt->setRemotePort(DHCP6_CLIENT_PORT);
+    }
+
+    // Forward packet to the client.
+    IfaceMgr::instance().send(pkt);
+    // processStatsSent(pkt);
+}
+
+};  // namespace dhcp
+
+};  // namespace isc

src/bin/dhcp6/dhcp6to4_ipc.h

@@ -0,0 +1,53 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef DHCP6TO4_IPC_H
+#define DHCP6TO4_IPC_H
+
+/// @file dhcp6to4_ipc.h Defines the Dhcp6to4Ipc class.
+/// This file defines the class Kea uses to act as the DHCPv6 server
+/// side of DHCPv4-over-DHCPv6 communication between servers.
+///
+#include <dhcpsrv/dhcp4o6_ipc.h>
+#include <boost/shared_ptr.hpp>
+
+namespace isc {
+namespace dhcp {
+
+/// @brief Handles DHCPv4-over-DHCPv6 IPC on the DHCPv6 server side
+class Dhcp6to4Ipc : public Dhcp4o6IpcBase {
+protected:
+    /// @brief Constructor
+    ///
+    /// Default constructor
+    Dhcp6to4Ipc();
+
+    /// @brief Destructor.
+    virtual ~Dhcp6to4Ipc() { }
+
+public:
+    /// @brief Returns pointer to the sole instance of Dhcp6to4Ipc
+    ///
+    /// Dhcp6to4Ipc is a singleton class
+    ///
+    /// @return the only existing instance of DHCP4o6 IPC
+    static Dhcp6to4Ipc& instance();
+
+    /// @brief Open communication socket
+    ///
+    /// Call base open method and sets the handler/callback when needed
+    virtual void open();
+
+    /// @brief On receive handler
+    ///
+    /// The handler sends the DHCPv6 packet back to the remote address
+    static void handler();
+};
+
+} // namespace isc
+} // namespace dhcp
+
+#endif

src/bin/dhcp6/tests/Makefile.am

@@ -94,8 +94,8 @@ dhcp6_unittests_SOURCES += confirm_unittest.cc
 dhcp6_unittests_SOURCES += infrequest_unittest.cc
 dhcp6_unittests_SOURCES += decline_unittest.cc
 dhcp6_unittests_SOURCES += dhcp6_message_test.cc dhcp6_message_test.h
-
 dhcp6_unittests_SOURCES += kea_controller_unittest.cc
+dhcp6_unittests_SOURCES += dhcp6to4_ipc_unittest.cc
 
 nodist_dhcp6_unittests_SOURCES  = marker_file.h test_libraries.h
 

src/bin/dhcp6/tests/dhcp6to4_ipc_unittest.cc

@@ -0,0 +1,135 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+#include <asiolink/io_address.h>
+#include <dhcp/pkt6.h>
+#include <dhcp/iface_mgr.h>
+#include <dhcp/tests/iface_mgr_test_config.h>
+#include <dhcp/tests/pkt_filter6_test_stub.h>
+#include <dhcp6/dhcp6to4_ipc.h>
+#include <dhcpsrv/cfgmgr.h>
+#include <dhcpsrv/testutils/dhcp4o6_test_ipc.h>
+#include <gtest/gtest.h>
+#include <stdint.h>
+
+using namespace isc;
+using namespace isc::asiolink;
+using namespace isc::dhcp;
+using namespace isc::dhcp::test;
+using namespace isc::util;
+
+namespace {
+
+/// @brief Port number used in tests.
+const uint16_t TEST_PORT = 32000;
+
+/// @brief Define short name for the test IPC.
+typedef Dhcp4o6TestIpc TestIpc;
+
+/// @brief Test fixture class for DHCPv4 endpoint of DHCPv4o6 IPC.
+class Dhcp6to4IpcTest : public ::testing::Test {
+public:
+
+    /// @brief Constructor
+    ///
+    /// Configures IPC to use a test port. It also provides a fake
+    /// configuration of interfaces and opens IPv6 sockets.
+    Dhcp6to4IpcTest()
+        : iface_mgr_test_config_(true) {
+        IfaceMgr::instance().openSockets6();
+        configurePort(TEST_PORT);
+    }
+
+    /// @brief Configure DHCP4o6 port.
+    ///
+    /// @param port New port.
+    void configurePort(const uint16_t port);
+
+    /// @brief Creates an instance of the DHCPv4o6 Message option.
+    ///
+    /// The option will contain an empty DHCPREQUEST message, with
+    /// just the Message Type option inside and nothing else.
+    ///
+    /// @return Pointer to the instance of the DHCPv4-query Message option.
+    OptionPtr createDHCPv4MsgOption() const;
+
+private:
+
+    /// @brief Provides fake configuration of interfaces.
+    IfaceMgrTestConfig iface_mgr_test_config_;
+};
+
+void
+Dhcp6to4IpcTest::configurePort(const uint16_t port) {
+    CfgMgr::instance().getStagingCfg()->setDhcp4o6Port(port);
+}
+
+OptionPtr
+Dhcp6to4IpcTest::createDHCPv4MsgOption() const {
+    // Create the DHCPv4 message.
+    Pkt4Ptr pkt(new Pkt4(DHCPREQUEST, 1234));
+    // Make a wire representation of the DHCPv4 message.
+    pkt->pack();
+    OutputBuffer& output_buffer = pkt->getBuffer();
+    const uint8_t* data = static_cast<const uint8_t*>(output_buffer.getData());
+    OptionBuffer option_buffer(data, data + output_buffer.getLength());
+
+    // Create the DHCPv4 Message option holding the created message.
+    OptionPtr opt_msg(new Option(Option::V6, D6O_DHCPV4_MSG, option_buffer));
+    return (opt_msg);
+}
+
+// This test verifies that the IPC returns an error when trying to bind
+// to the out of range port.
+TEST_F(Dhcp6to4IpcTest, invalidPortError) {
+    // Create instance of the IPC endpoint under test with out-of-range port.
+    configurePort(65535);
+    Dhcp6to4Ipc& ipc = Dhcp6to4Ipc::instance();
+    EXPECT_THROW(ipc.open(), isc::OutOfRange);
+}
+
+// This test verifies that the DHCPv4 endpoint of the DHCPv4o6 IPC can
+// receive messages.
+TEST_F(Dhcp6to4IpcTest, receive) {
+    // Create instance of the IPC endpoint under test.
+    Dhcp6to4Ipc& ipc = Dhcp6to4Ipc::instance();
+    // Create instance of the IPC endpoint being used as a source of messages.
+    TestIpc src_ipc(TEST_PORT, TestIpc::ENDPOINT_TYPE_V4);
+
+    // Open both endpoints.
+    ASSERT_NO_THROW(ipc.open());
+    ASSERT_NO_THROW(src_ipc.open());
+
+    // Create message to be sent over IPC.
+    Pkt6Ptr pkt(new Pkt6(DHCPV6_DHCPV4_QUERY, 1234));
+    pkt->addOption(createDHCPv4MsgOption());
+    pkt->setIface("eth0");
+    pkt->setRemoteAddr(IOAddress("2001:db8:1::123"));
+    ASSERT_NO_THROW(pkt->pack());
+
+    // Send and wait up to 1 second to receive it.
+    ASSERT_NO_THROW(src_ipc.send(pkt));
+    ASSERT_NO_THROW(IfaceMgr::instance().receive6(1, 0));
+
+#if 0
+    // The stub packet filter exposes static function to retrieve messages
+    // sent over the fake sockets/interfaces. This is the message that the
+    // IPC endpoint should forward to the client after receiving it
+    // from the DHCPv4 server.
+    Pkt6Ptr forwarded = PktFilter6TestStub::popSent();
+    ASSERT_TRUE(forwarded);
+
+    // Verify the packet received.
+    EXPECT_EQ(DHCP6_CLIENT_PORT, forwarded->getRemotePort());
+    EXPECT_EQ(forwarded->getType(), pkt->getType());
+    EXPECT_TRUE(forwarded->getOption(D6O_DHCPV4_MSG));
+    EXPECT_EQ("eth0", forwarded->getIface());
+    EXPECT_EQ("2001:db8:1::123", forwarded->getRemoteAddr().toText());
+#endif
+}
+
+} // end of anonymous namespace

src/lib/dhcpsrv/dhcp4o6_ipc.cc

@@ -1,27 +1,23 @@
 // Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
 //
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #include <config.h>
 
 #include <dhcp/dhcp6.h>
 #include <dhcp/iface_mgr.h>
 #include <dhcp/option6_addrlst.h>
+#include <dhcp/option_custom.h>
 #include <dhcp/option_string.h>
 #include <dhcp/option_vendor.h>
 #include <dhcpsrv/dhcp4o6_ipc.h>
 #include <dhcpsrv/dhcpsrv_log.h>
 
+#include <boost/pointer_cast.hpp>
+
+#include <errno.h>
 #include <netinet/in.h>
 #include <sys/fcntl.h>
 #include <string>
@@ -39,41 +35,26 @@ Dhcp4o6IpcBase::~Dhcp4o6IpcBase() {
     close();
 }
 
-int Dhcp4o6IpcBase::open(uint16_t port, int side) {
+int Dhcp4o6IpcBase::open(uint16_t port, EndpointType endpoint_type) {
+    // Don't check if the value is greater than 65534 as it is done
+    // by callers before they cast the value to 16 bits.
+
     if (port == port_) {
         // No change: nothing to do
         return (socket_fd_);
     }
 
-    // Port 0: closing
-    if (port == 0) {
-        port_ = 0;
-        if (socket_fd_ != -1) {
-            IfaceMgr::instance().deleteExternalSocket(socket_fd_);
-            ::close(socket_fd_);
-            socket_fd_ = -1;
-        }
-        return (socket_fd_);
-    }
-
     // Open socket
     int sock = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
     if (sock < 0) {
-        isc_throw(Unexpected, "Failed to create DHCP4o6 socket.");
-    }
-
-    // Set reuse address
-    int flag = 1;
-    if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
-                   (char *)&flag, sizeof(flag)) < 0) {
-        ::close(sock);
-        isc_throw(Unexpected, "Failed to set SO_REUSEADDR on DHCP4o6 socket.");
+        isc_throw(Dhcp4o6IpcError, "Failed to create DHCP4o6 socket.");
     }
 
     // Set no blocking
     if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
         ::close(sock);
-        isc_throw(Unexpected, "Failed to set O_NONBLOCK on DHCP4o6 socket.");
+        isc_throw(Dhcp4o6IpcError,
+                  "Failed to set O_NONBLOCK on DHCP4o6 socket.");
     }
 
     // Bind to the local address
@@ -83,7 +64,7 @@ int Dhcp4o6IpcBase::open(uint16_t port, int side) {
 #ifdef HAVE_SA_LEN
     local6.sin6_len = sizeof(local6);
 #endif
-    if (side == 6) {
+    if (endpoint_type == ENDPOINT_TYPE_V6) {
         local6.sin6_port = htons(port);
     } else {
         local6.sin6_port = htons(port + 1);
@@ -92,7 +73,7 @@ int Dhcp4o6IpcBase::open(uint16_t port, int side) {
     local6.sin6_addr.s6_addr[15] = 1;
     if (bind(sock, (struct sockaddr *)&local6, sizeof(local6)) < 0) {
         ::close(sock);
-        isc_throw(Unexpected, "Failed to bind DHCP4o6 socket.");
+        isc_throw(Dhcp4o6IpcError, "Failed to bind DHCP4o6 socket.");
     }
 
     // Connect to the remote address
@@ -102,7 +83,7 @@ int Dhcp4o6IpcBase::open(uint16_t port, int side) {
 #ifdef HAVE_SA_LEN
     remote6.sin6_len = sizeof(remote6);
 #endif
-    if (side == 6) {
+    if (endpoint_type == ENDPOINT_TYPE_V6) {
         remote6.sin6_port = htons(port + 1);
     } else {
         remote6.sin6_port = htons(port);
@@ -113,13 +94,13 @@ int Dhcp4o6IpcBase::open(uint16_t port, int side) {
     if (connect(sock, reinterpret_cast<const struct sockaddr*>(&remote6),
                 sizeof(remote6)) < 0) {
         ::close(sock);
-        isc_throw(Unexpected, "Failed to connect DHCP4o6 socket.");
+        isc_throw(Dhcp4o6IpcError, "Failed to connect DHCP4o6 socket.");
     }
 
     if (socket_fd_ != -1) {
         if (dup2(sock, socket_fd_) == -1) {
             ::close(sock);
-            isc_throw(Unexpected, "Failed to duplicate DHCP4o6 socket.");
+            isc_throw(Dhcp4o6IpcError, "Failed to duplicate DHCP4o6 socket.");
         }
         if (sock != socket_fd_) {
             ::close(sock);
@@ -134,113 +115,149 @@ int Dhcp4o6IpcBase::open(uint16_t port, int side) {
 }
 
 void Dhcp4o6IpcBase::close() {
-    static_cast<void>(open(0, 0));
+    port_ = 0;
+    if (socket_fd_ != -1) {
+        IfaceMgr::instance().deleteExternalSocket(socket_fd_);
+        ::close(socket_fd_);
+        socket_fd_ = -1;
+    }
 }
 
 Pkt6Ptr Dhcp4o6IpcBase::receive() {
     uint8_t buf[65536];
     ssize_t cc = recv(socket_fd_, buf, sizeof(buf), 0);
     if (cc < 0) {
-        isc_throw(Unexpected, "Failed to receive on DHCP4o6 socket.");
+        isc_throw(Dhcp4o6IpcError, "Failed to receive on DHCP4o6 socket.");
     }
     Pkt6Ptr pkt = Pkt6Ptr(new Pkt6(buf, cc));
     pkt->updateTimestamp();
 
     // Get interface name and remote address
     pkt->unpack();
-    OptionVendorPtr vendor =
-        boost::dynamic_pointer_cast<OptionVendor>(pkt->getOption(D6O_VENDOR_OPTS));
-    if (!vendor) {
-        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE_DETAIL,
-                  DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
-            .arg("no vendor option");
-        return (Pkt6Ptr());
-    }
-    if (vendor->getVendorId() != ENTERPRISE_ID_ISC) {
-        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE_DETAIL,
-                  DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
-            .arg("vendor option enterprise ID is not ISC");
-        return (Pkt6Ptr());
-    }
-    OptionStringPtr ifname =
-        boost::dynamic_pointer_cast<OptionString>(vendor->getOption(ISC_V6_4O6_INTERFACE));
+
+    // Vendor option is initially NULL. If we find the instance of the vendor
+    // option with the ISC enterprise id this pointer will point to it.
+    OptionVendorPtr option_vendor;
+
+    // Get all vendor option and look for the one with the ISC enterprise id.
+    OptionCollection vendor_options = pkt->getOptions(D6O_VENDOR_OPTS);
+    for (OptionCollection::const_iterator opt = vendor_options.begin();
+         opt != vendor_options.end(); ++opt) {
+        option_vendor = boost::dynamic_pointer_cast<OptionVendor>(opt->second);
+        if (option_vendor) {
+            if (option_vendor->getVendorId() == ENTERPRISE_ID_ISC) {
+                break;
+            }
+            option_vendor.reset();
+        }
+    }
+         
+    // Vendor option must exist.
+    if (!option_vendor) {
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+            .arg("no ISC vendor option");
+        isc_throw(Dhcp4o6IpcError, "option " << D6O_VENDOR_OPTS
+                  << " with ISC enterprise id is not present in the DHCP4o6"
+                  " message sent between the servers");
+    }
+
+    // The option carrying interface name is required.
+    OptionStringPtr ifname = boost::dynamic_pointer_cast<
+        OptionString>(option_vendor->getOption(ISC_V6_4O6_INTERFACE));
     if (!ifname) {
-        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE_DETAIL,
-                  DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
             .arg("no interface suboption");
-        return (Pkt6Ptr());
+        isc_throw(Dhcp4o6IpcError, "option " << D6O_VENDOR_OPTS
+                  << " doesn't contain the " << ISC_V6_4O6_INTERFACE
+                  << " option required in the DHCP4o6 message sent"
+                  " between Kea servers");
     }
+
+    // Check if this interface is present in the system.
     IfacePtr iface = IfaceMgr::instance().getIface(ifname->getValue());
     if (!iface) {
-        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE_DETAIL,
-                  DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
             .arg("can't get interface " + ifname->getValue());
-        return (Pkt6Ptr());
+        isc_throw(Dhcp4o6IpcError, "option " << ISC_V6_4O6_INTERFACE
+                  << " sent in the DHCP4o6 message contains non-existing"
+                  " interface name '" << ifname->getValue() << "'");
     }
-    Option6AddrLstPtr srcs =
-        boost::dynamic_pointer_cast<Option6AddrLst>(vendor->getOption(ISC_V6_4O6_SRC_ADDRESS));
+
+    // Get the option holding source IPv6 address.
+    OptionCustomPtr srcs = boost::dynamic_pointer_cast<
+        OptionCustom>(option_vendor->getOption(ISC_V6_4O6_SRC_ADDRESS));
     if (!srcs) {
-        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE_DETAIL,
-                  DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
             .arg("no source address suboption");
-        return (Pkt6Ptr());
-    }
-    Option6AddrLst::AddressContainer addrs = srcs->getAddresses();
-    if (addrs.size() != 1) {
-        LOG_DEBUG(dhcpsrv_logger, DHCPSRV_DBG_TRACE_DETAIL,
-                  DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
-            .arg("bad source address suboption");
-        return (Pkt6Ptr());
+        isc_throw(Dhcp4o6IpcError, "option " << D6O_VENDOR_OPTS
+                  << " doesn't contain the " << ISC_V6_4O6_SRC_ADDRESS
+                  << " option required in the DHCP4o6 message sent"
+                  " between Kea servers");
     }
 
-    // Update the packet and return it
-    static_cast<void>(pkt->delOption(D6O_VENDOR_OPTS));
-    pkt->setRemoteAddr(addrs[0]);
+    // Update the packet.
+    pkt->setRemoteAddr(srcs->readAddress());
     pkt->setIface(iface->getName());
     pkt->setIndex(iface->getIndex());
+
+    // Remove options that have been added by the IPC sender.
+    static_cast<void>(option_vendor->delOption(ISC_V6_4O6_INTERFACE));
+    static_cast<void>(option_vendor->delOption(ISC_V6_4O6_SRC_ADDRESS));
+
+    // If there are no more options, the IPC sender has probably created the
+    // vendor option, in which case we should remove it here.
+    if (option_vendor->getOptions().empty()) {
+        static_cast<void>(pkt->delOption(D6O_VENDOR_OPTS));
+    }
+
     return (pkt);
 }
 
-void Dhcp4o6IpcBase::send(Pkt6Ptr pkt) {
-    // No packet: nothing to send
+void Dhcp4o6IpcBase::send(const Pkt6Ptr& pkt) {
+    // This shouldn't happen, i.e. send() shouldn't be called if there is
+    // no message.
     if (!pkt) {
-        return;
+        isc_throw(Dhcp4o6IpcError, "DHCP4o6 message must not be NULL while"
+                  " trying to send it over the IPC");
     }
 
     // Disabled: nowhere to send
     if (socket_fd_ == -1) {
-        return;
+        isc_throw(Dhcp4o6IpcError, "unable to send DHCP4o6 message because"
+                  " IPC socket is closed");
     }
 
     // Check if vendor option exists.
-    OptionVendorPtr vendor_opt = boost::dynamic_pointer_cast<
+    OptionVendorPtr option_vendor = boost::dynamic_pointer_cast<
         OptionVendor>(pkt->getOption(D6O_VENDOR_OPTS));
 
     // If vendor option doesn't exist or its enterprise id is not ISC's
     // enterprise id, let's create it.
-    if (!vendor_opt || (vendor_opt->getVendorId() != ENTERPRISE_ID_ISC)) {
-        vendor_opt.reset(new OptionVendor(Option::V6, ENTERPRISE_ID_ISC));
+    if (!option_vendor ||
+        (option_vendor->getVendorId() != ENTERPRISE_ID_ISC)) {
+        option_vendor.reset(new OptionVendor(Option::V6, ENTERPRISE_ID_ISC));
+        pkt->addOption(option_vendor);
 
     }
 
     // Push interface name and source address in it
-    vendor_opt->addOption(OptionPtr(new OptionString(Option::V6,
-                                                     ISC_V6_4O6_INTERFACE,
-                                                     pkt->getIface())));
-    vendor_opt->addOption(OptionPtr(new Option6AddrLst(ISC_V6_4O6_SRC_ADDRESS,
+    option_vendor->addOption(OptionStringPtr(new OptionString(Option::V6,
+                                                       ISC_V6_4O6_INTERFACE,
+                                                       pkt->getIface())));
+    option_vendor->addOption(Option6AddrLstPtr(new Option6AddrLst(
+                                                       ISC_V6_4O6_SRC_ADDRESS,
                                                        pkt->getRemoteAddr())));
-    pkt->addOption(vendor_opt);
-
     // Get packet content
     OutputBuffer& buf = pkt->getBuffer();
     buf.clear();
     pkt->pack();
 
-    // Send
-    if (::send(socket_fd_, buf.getData(), buf.getLength(), 0) < 0) {
-        isc_throw(Unexpected, "Failed to send over DHCP4o6 IPC socket");
-    }
-    return;
+    // Try to send the message.
+   if (::send(socket_fd_, buf.getData(), buf.getLength(), 0) < 0) {
+       isc_throw(Dhcp4o6IpcError,
+                 "failed to send DHCP4o6 message over the IPC: "
+                 << strerror(errno));
+   }
 }
 
 };  // namespace dhcp

src/lib/dhcpsrv/dhcp4o6_ipc.h

@@ -1,16 +1,8 @@
 // Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
 //
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #ifndef DHCP4O6_IPC_H
 #define DHCP4O6_IPC_H
@@ -19,18 +11,62 @@
 /// This file defines the class Kea uses as a base for
 /// DHCPv4-over-DHCPv6 communication between servers.
 ///
-#include <dhcp/pkt6.h>
 
+#include <exceptions/exceptions.h>
+#include <dhcp/pkt6.h>
 #include <boost/noncopyable.hpp>
-
 #include <stdint.h>
 
 namespace isc {
 namespace dhcp {
 
-/// @brief 
+/// @brief Exception thrown when error occurs as a result of use of IPC.
+class Dhcp4o6IpcError : public Exception {
+public:
+    Dhcp4o6IpcError(const char* file, size_t line, const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
+/// @brief This class implements the communication between the DHCPv4
+/// and DHCPv6 servers to allow for transmission of the DHCPv4 query
+/// and DHCPv4 response messages.
+///
+/// When the DHCPv6 server receives the DHCPv4 query message it needs
+/// to forward it to the DHCPv4 server for processing. The DHCPv4
+/// server processes the message and answers with the DHCPv4 response
+/// message to the DHCPv6 server. The server forwards it back to the
+/// client. This class implements the communication between the DHCPv4
+/// and DHCPv6 servers to allow for transmission of the DHCPv4 query
+/// and DHCPv6 response messages.
 ///
+/// This class creates a socket (when @c open is called) and binds it
+/// to a port, depending on the configuration. The port number is
+/// explicitly specified in the server configuration. This explicit
+/// port value is used directly on the DHCPv6 server side. The DHCPv4
+/// server uses the port specified + 1.
+///
+/// The DHCPv4 and DHCPv6 servers use distinct instances of classes derived
+/// from this base class. Each of these instances is used to send and
+/// receive messages sent by the other server.
+///
+/// In order to make address allocation decisions, the DHCPv4 server
+/// requires information about the interface and the source address of
+/// the original DHCPv4 query message sent by the client. This
+/// information is known by the DHCPv6 server and needs to be conveyed
+/// to the DHCPv4 server. The IPC conveys it in the
+/// @c ISC_V6_4O6_INTERFACE and @c ISC_V6_4O6_SRC_ADDRESS options
+/// within the Vendor Specific Information option, with ISC
+/// enterprise id. These options are added by the IPC sender and removed
+/// by the IPC receiver.
 class Dhcp4o6IpcBase : public boost::noncopyable {
+public:
+
+    /// @brief Endpoint type: DHCPv4 or DHCPv6 server.
+    enum EndpointType {
+        ENDPOINT_TYPE_V4 = 4,
+        ENDPOINT_TYPE_V6 = 6
+    };
+
 protected:
     /// @brief Constructor
     ///
@@ -40,38 +76,52 @@ protected:
     /// @brief Destructor.
     virtual ~Dhcp4o6IpcBase();
 
-    /// @brief Open communication socket (from base class)
+    /// @brief Open communication socket (from base class).
     ///
-    /// @param port port number to use (0 for disabled)
-    /// @param side side of the server (4 or 6)
+    /// @param port Port number to use. The socket is bound to this port
+    /// if the endpoint type is DHCPv6 server, otherwise the port + 1
+    /// value is used.
+    /// @param endpoint_type Endpoint type (DHCPv4 or DHCPv6 server).
     ///
-    /// @return new socket descriptor
-    int open(uint16_t port, int side);
+    /// @return New socket descriptor.
+    /// @throw isc::dhcp::Dhcp4o6IpcError on system call errors.
+    int open(uint16_t port, EndpointType endpoint_type);
 
 public:
-    /// @brief Open communication socket (for derived classes)
+
+    /// @brief Open communication socket (for derived classes).
     virtual void open() = 0;
 
-    /// @brief Close communication socket
+    /// @brief Close communication socket.
     void close();
 
-    /// @brief Receive IPC message
+    /// @brief Receive message over IPC.
     ///
     /// @return a pointer to a DHCPv6 message with interface and remote
     /// address set from the IPC message
+    /// @throw isc::dhcp::Dhcp4o6IpcError on system call error or
+    /// malformed packets.
     Pkt6Ptr receive();
 
-    /// @brief Send IPC message
+    /// @brief Send message over IPC.
     ///
-    /// @param a pointer to a DHCPv6 message with interface and remote
-    /// address set for the IPC message
-    void send(Pkt6Ptr pkt);
+    /// The IPC uses @c ISC_V6_4O6_INTERFACE and @c ISC_V6_4O6_SRC_ADDRESS
+    /// options conveyed within the Vendor Specific Information option, with
+    /// ISC enterprise id, to communicate the client remote address and the
+    /// interface on which the DHCPv4 query was received. These options will
+    /// be removed by the receiver.
+    ///
+    /// @param pkt Pointer to a DHCPv6 message with interface and remote
+    /// address.
+    /// @throw isc::dhcp::Dhcp4o6IpcError.
+    void send(const Pkt6Ptr& pkt);
 
 protected:
-    /// @brief Port number
+
+    /// @brief Port number configured for IPC communication.
     uint16_t port_;
 
-    /// @brief Socket descriptor
+    /// @brief Socket descriptor.
     int socket_fd_;
 };
 

src/lib/dhcpsrv/tests/Makefile.am

@@ -92,6 +92,7 @@ libdhcpsrv_unittests_SOURCES += d2_udp_unittest.cc
 libdhcpsrv_unittests_SOURCES += daemon_unittest.cc
 libdhcpsrv_unittests_SOURCES += database_connection_unittest.cc
 libdhcpsrv_unittests_SOURCES += dbaccess_parser_unittest.cc
+libdhcpsrv_unittests_SOURCES += dhcp4o6_ipc_unittest.cc
 libdhcpsrv_unittests_SOURCES += duid_config_parser_unittest.cc
 libdhcpsrv_unittests_SOURCES += expiration_config_parser_unittest.cc
 libdhcpsrv_unittests_SOURCES += host_mgr_unittest.cc

src/lib/dhcpsrv/tests/dhcp4o6_ipc_unittest.cc

@@ -1,16 +1,8 @@
 // Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
 //
-// Permission to use, copy, modify, and/or distribute this software for any
-// purpose with or without fee is hereby granted, provided that the above
-// copyright notice and this permission notice appear in all copies.
-//
-// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
-// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
-// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
-// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
-// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
-// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
-// PERFORMANCE OF THIS SOFTWARE.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 #include <config.h>
 #include <dhcp/iface_mgr.h>
@@ -42,7 +34,7 @@ const uint16_t TEST_PORT = 12345;
 const uint16_t TEST_ITERATIONS = 10;
 
 /// @brief Type definition for the function creating DHCP message.
-typedef boost::function<Pkt6Ptr(const uint16_t, const uint16_t)> CreateMsgFun;
+typedef boost::function<Pkt6Ptr(uint16_t, uint16_t)> CreateMsgFun;
 
 /// @brief Define short name for test IPC class.
 typedef Dhcp4o6TestIpc TestIpc;
@@ -65,7 +57,7 @@ protected:
     /// @param prefix Prefix.
     /// @param postfix Postfix.
     /// @return String representing concatenated prefix and postfix.
-    static std::string concatenate(const std::string& prefix, const uint16_t postfix);
+    static std::string concatenate(const std::string& prefix, uint16_t postfix);
 
     /// @brief Creates an instance of the DHCPv4o6 message.
     ////
@@ -77,19 +69,20 @@ protected:
     /// the "eth0" will be used, for odd postfix values "eth1" will be used.
     ///
     /// @return Pointer to the created message.
-    static Pkt6Ptr createDHCPv4o6Message(const uint16_t msg_type,
-                                         const uint16_t postfix = 0);
+    static Pkt6Ptr createDHCPv4o6Message(uint16_t msg_type,
+                                         uint16_t postfix = 0);
 
     /// @brief Creates an instance of the DHCPv4o6 message with vendor option.
     ///
     /// @param msg_type Message type.
     /// @param postfix Postfix to be appended to the remote address. See the
     /// documentation of @c createDHCPv4o6Message for details.
+    /// @param enterprise_id Enterprise ID for the vendor option.
     ///
     /// @return Pointer to the created message.
-    static Pkt6Ptr createDHCPv4o6MsgWithVendorOption(const uint16_t msg_type,
-                                                     const uint16_t postfix,
-                                                     const uint32_t enterprise_id);
+    static Pkt6Ptr createDHCPv4o6MsgWithVendorOption(uint16_t msg_type,
+                                                     uint16_t postfix,
+                                                     uint32_t enterprise_id);
 
     /// @brief Creates an instance of the DHCPv4o6 message with ISC
     /// vendor option.
@@ -102,8 +95,8 @@ protected:
     /// documentation of @c createDHCPv4o6Message for details.
     ///
     /// @return Pointer to the created message.
-    static Pkt6Ptr createDHCPv4o6MsgWithISCVendorOption(const uint16_t msg_type,
-                                                        const uint16_t postfix);
+    static Pkt6Ptr createDHCPv4o6MsgWithISCVendorOption(uint16_t msg_type,
+                                                        uint16_t postfix);
 
     /// @brief Creates an instance of the DHCPv4o6 message with vendor
     /// option holding enterprise id of 32000.
@@ -117,23 +110,24 @@ protected:
     /// documentation of @c createDHCPv4o6Message for details.
     ///
     /// @return Pointer to the created message.
-    static Pkt6Ptr createDHCPv4o6MsgWithAnyVendorOption(const uint16_t msg_type,
-                                                        const uint16_t postfix);
+    static Pkt6Ptr createDHCPv4o6MsgWithAnyVendorOption(uint16_t msg_type,
+                                                        uint16_t postfix);
 
     /// @brief Creates an instance of the DHCPv4o6 Message option.
     ///
     /// @param src Type of the source endpoint. It can be 4 or 6.
     /// @return Pointer to the instance of the option.
-    static OptionPtr createDHCPv4MsgOption(const TestIpc::EndpointType& src);
+    static OptionPtr createDHCPv4MsgOption(TestIpc::EndpointType src);
 
     /// @brief Tests sending and receiving packets over the IPC.
     ///
     /// @param iterations_num Number of packets to be sent over the IPC.
     /// @param src Type of the source IPC endpoint. It can be 4 or 6.
     /// @param dest Type of the destination IPC endpoint. It can be 4 or 6.
-    void testSendReceive(const uint16_t iterations_num,
-                         const TestIpc::EndpointType& src,
-                         const TestIpc::EndpointType& dest,
+    /// @param create_msg_fun Function called to create the packet.
+    void testSendReceive(uint16_t iterations_num,
+                         TestIpc::EndpointType src,
+                         TestIpc::EndpointType dest,
                          const CreateMsgFun& create_msg_fun);
 
     /// @brief Tests that error is reported when invalid message is received.
@@ -154,15 +148,15 @@ Dhcp4o6IpcBaseTest::Dhcp4o6IpcBaseTest()
 
 std::string
 Dhcp4o6IpcBaseTest::concatenate(const std::string& prefix,
-                                const uint16_t postfix) {
+                                uint16_t postfix) {
     std::ostringstream s;
     s << prefix << postfix;
     return (s.str());
 }
 
 Pkt6Ptr
-Dhcp4o6IpcBaseTest::createDHCPv4o6Message(const uint16_t msg_type,
-                                          const uint16_t postfix) {
+Dhcp4o6IpcBaseTest::createDHCPv4o6Message(uint16_t msg_type,
+                                          uint16_t postfix) {
     // Create the DHCPv4o6 message.
     Pkt6Ptr pkt(new Pkt6(msg_type, 0));
 
@@ -180,7 +174,7 @@ Dhcp4o6IpcBaseTest::createDHCPv4o6Message(const uint16_t msg_type,
     pkt->setRemoteAddr(IOAddress(concatenate("2001:db8:1::", postfix)));
 
     // Determine the endpoint type using the message type.
-    const TestIpc::EndpointType src = (msg_type ==  DHCPV6_DHCPV4_QUERY) ?
+    TestIpc::EndpointType src = (msg_type ==  DHCPV6_DHCPV4_QUERY) ?
         TestIpc::ENDPOINT_TYPE_V6 : TestIpc::ENDPOINT_TYPE_V4;
 
     // Add DHCPv4 Message option to make sure it is conveyed by the IPC.
@@ -190,9 +184,9 @@ Dhcp4o6IpcBaseTest::createDHCPv4o6Message(const uint16_t msg_type,
 }
 
 Pkt6Ptr
-Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithVendorOption(const uint16_t msg_type,
-                                                      const uint16_t postfix,
-                                                      const uint32_t enterprise_id) {
+Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithVendorOption(uint16_t msg_type,
+                                                      uint16_t postfix,
+                                                      uint32_t enterprise_id) {
     Pkt6Ptr pkt = createDHCPv4o6Message(msg_type, postfix);
 
     // Create vendor option with ISC enterprise id.
@@ -208,19 +202,19 @@ Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithVendorOption(const uint16_t msg_type,
 }
 
 Pkt6Ptr
-Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithISCVendorOption(const uint16_t msg_type,
-                                                         const uint16_t postfix) {
+Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithISCVendorOption(uint16_t msg_type,
+                                                         uint16_t postfix) {
     return (createDHCPv4o6MsgWithVendorOption(msg_type, postfix, ENTERPRISE_ID_ISC));
 }
 
 Pkt6Ptr
-Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithAnyVendorOption(const uint16_t msg_type,
-                                                         const uint16_t postfix) {
+Dhcp4o6IpcBaseTest::createDHCPv4o6MsgWithAnyVendorOption(uint16_t msg_type,
+                                                         uint16_t postfix) {
     return (createDHCPv4o6MsgWithVendorOption(msg_type, postfix, 32000));
 }
 
 OptionPtr
-Dhcp4o6IpcBaseTest::createDHCPv4MsgOption(const TestIpc::EndpointType& src) {
+Dhcp4o6IpcBaseTest::createDHCPv4MsgOption(TestIpc::EndpointType src) {
     // Create the DHCPv4 message.
     Pkt4Ptr pkt(new Pkt4(src == TestIpc::ENDPOINT_TYPE_V4 ? DHCPACK : DHCPREQUEST,
                          1234));
@@ -236,9 +230,9 @@ Dhcp4o6IpcBaseTest::createDHCPv4MsgOption(const TestIpc::EndpointType& src) {
 }
 
 void
-Dhcp4o6IpcBaseTest::testSendReceive(const uint16_t iterations_num,
-                                    const TestIpc::EndpointType& src,
-                                    const TestIpc::EndpointType& dest,
+Dhcp4o6IpcBaseTest::testSendReceive(uint16_t iterations_num,
+                                    TestIpc::EndpointType src,
+                                    TestIpc::EndpointType dest,
                                     const CreateMsgFun& create_msg_fun) {
     // Create IPC instances representing the source and destination endpoints.
     TestIpc ipc_src(TEST_PORT, src);
@@ -248,7 +242,7 @@ Dhcp4o6IpcBaseTest::testSendReceive(const uint16_t iterations_num,
     ASSERT_NO_THROW(ipc_src.open());
     ASSERT_NO_THROW(ipc_dest.open());
 
-    // Depnding if we're sending from DHCPv6 to DHCPv4 or the opposite
+    // Depending if we're sending from DHCPv6 to DHCPv4 or the opposite
     // direction we use different message type. This is not really required
     // for testing IPC, but it better simulates the real use case.
     uint16_t msg_type = (src == TestIpc::ENDPOINT_TYPE_V6 ? DHCPV6_DHCPV4_QUERY :
@@ -437,40 +431,17 @@ TEST_F(Dhcp4o6IpcBaseTest, openError) {
     ASSERT_NE(-1, ipc_bound.getSocketFd());
 
     ipc.setDesiredPort(TEST_PORT + 10);
-#if defined(OS_LINUX)
-    // Linux has a silly interpretation of SO_REUSEADDR so we use
-    // another way to raise an error.
-    ipc.setDesiredPort(65535);
-#endif
     ASSERT_THROW(ipc.open(), isc::dhcp::Dhcp4o6IpcError);
 
     EXPECT_EQ(sock_fd, ipc.getSocketFd());
     EXPECT_EQ(TEST_PORT, ipc.getPort());
 
     ASSERT_NO_THROW(ipc_bound.close());
-#if defined(OS_LINUX)
-    // Restore the expected value
-    ipc.setDesiredPort(TEST_PORT + 10);
-#endif
     ASSERT_NO_THROW(ipc.open());
     EXPECT_NE(-1, ipc.getSocketFd());
     EXPECT_EQ(TEST_PORT + 10, ipc.getPort());
 }
 
-// This test verifies that the IPC returns an error when trying to bind
-// to the out of range port.
-TEST_F(Dhcp4o6IpcBaseTest, invalidPortError4) {
-    TestIpc ipc(65535, TestIpc::ENDPOINT_TYPE_V4);
-    EXPECT_THROW(ipc.open(), Dhcp4o6IpcError);
-}
-
-// This test verifies that the IPC returns an error when trying to bind
-// to the out of range port.
-TEST_F(Dhcp4o6IpcBaseTest, invalidPortError6) {
-    TestIpc ipc(65535, TestIpc::ENDPOINT_TYPE_V6);
-    EXPECT_THROW(ipc.open(), Dhcp4o6IpcError);
-}
-
 // This test verifies that receiving packet over the IPC fails when there
 // is no vendor option present.
 TEST_F(Dhcp4o6IpcBaseTest, receiveWithoutVendorOption) {

src/lib/dhcpsrv/testutils/Makefile.am

@@ -12,7 +12,8 @@ if HAVE_GTEST
 
 noinst_LTLIBRARIES = libdhcpsrvtest.la
 
-libdhcpsrvtest_la_SOURCES = config_result_check.cc config_result_check.h
+libdhcpsrvtest_la_SOURCES  = config_result_check.cc config_result_check.h
+libdhcpsrvtest_la_SOURCES += dhcp4o6_test_ipc.cc dhcp4o6_test_ipc.h
 
 if HAVE_MYSQL
 libdhcpsrvtest_la_SOURCES += schema.cc schema.h

src/lib/dhcpsrv/testutils/dhcp4o6_test_ipc.cc

@@ -0,0 +1,41 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+#include <dhcp/iface_mgr.h>
+#include <dhcpsrv/testutils/dhcp4o6_test_ipc.h>
+#include <boost/bind.hpp>
+
+namespace isc {
+namespace dhcp {
+namespace test {
+
+Dhcp4o6TestIpc::Dhcp4o6TestIpc(uint16_t port, EndpointType endpoint_type)
+    : desired_port_(port), endpoint_type_(endpoint_type), pkt_received_() {
+}
+
+void
+Dhcp4o6TestIpc::open() {
+    // Use the base IPC to open the socket.
+    socket_fd_ = Dhcp4o6IpcBase::open(desired_port_, endpoint_type_);
+    // If the socket has been opened correctly, register it in the @c IfaceMgr.
+    // BTW if it has not an exception has been thrown so it is only
+    // a sanity / recommended check.
+    if (socket_fd_ != -1) {
+        IfaceMgr& iface_mgr = IfaceMgr::instance();
+        iface_mgr.addExternalSocket(socket_fd_,
+                boost::bind(&Dhcp4o6TestIpc::receiveHandler, this));
+    }
+}
+
+void
+Dhcp4o6TestIpc::receiveHandler() {
+    pkt_received_ = receive();
+}
+
+} // end of isc::dhcp::test namespace
+} // end of isc::dhcp namespace
+} // end of isc namespace

src/lib/dhcpsrv/testutils/dhcp4o6_test_ipc.h

@@ -0,0 +1,90 @@
+// Copyright (C) 2015-2016 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef DHCP4O6_TEST_IPC_H
+#define DHCP4O6_TEST_IPC_H
+
+#include <asiolink/io_address.h>
+#include <dhcp/iface_mgr.h>
+#include <dhcp/pkt6.h>
+#include <dhcpsrv/dhcp4o6_ipc.h>
+#include <boost/noncopyable.hpp>
+#include <stdint.h>
+
+namespace isc {
+namespace dhcp {
+namespace test {
+
+/// @brief Implements a simple IPC for the test.
+class Dhcp4o6TestIpc : public  Dhcp4o6IpcBase {
+public:
+
+    /// @brief Constructor.
+    ///
+    /// @param port Desired port.
+    /// @param endpoint_type Type of the IPC endpoint. It should be 4 or 6.
+    Dhcp4o6TestIpc(uint16_t port, EndpointType endpoint_type);
+
+    /// @brief Sets new port to be used with @c open.
+    ///
+    /// @param desired_port New desired port.
+    void setDesiredPort(uint16_t desired_port) {
+        desired_port_ = desired_port;
+    }
+
+    /// @brief Opens the IPC socket and registers it in @c IfaceMgr.
+    ///
+    /// This method opens the IPC socket and registers it as external
+    /// socket in the IfaceMgr. The @c TestIpc::receiveHandler is used as a
+    /// callback to be called by the @c IfaceMgr when the data is received
+    /// over the socket.
+    virtual void open();
+
+    /// @brief Retrieve port which socket is bound to.
+    uint16_t getPort() const {
+        return (port_);
+    }
+
+    /// @brief Retrieve socket descriptor.
+    int getSocketFd() const {
+        return (socket_fd_);
+    }
+
+    /// @brief Pops and returns a received message.
+    ///
+    /// @return Pointer to the received message over the IPC.
+    Pkt6Ptr popPktReceived() {
+        // Copy the received message.
+        Pkt6Ptr pkt_copy(pkt_received_);
+        // Set the received message to NULL (pop).
+        pkt_received_.reset();
+        // Return the copy.
+        return (pkt_copy);
+    }
+
+private:
+
+    /// @brief Callback for the IPC socket.
+    ///
+    /// This callback is called by the @c IfaceMgr when the data is received
+    /// over the IPC socket.
+    void receiveHandler();
+
+    /// @brief Port number.
+    uint16_t desired_port_;
+
+    /// @brief Endpoint type, i.e. 4 or 6.
+    EndpointType endpoint_type_;
+
+    /// @brief Pointer to the last received message.
+    Pkt6Ptr pkt_received_;
+};
+
+}; // end of isc::dhcp::test namespace
+}; // end of isc::dhcp namespace
+}; // end of isc namespace
+
+#endif // DHCP4O6_TEST_IPC_H