[3320] Basic implementation of the Requested IP Address support.

src/bin/dhcp4/dhcp4_srv.cc

@@ -942,7 +942,15 @@ Dhcpv4Srv::assignLease(const Pkt4Ptr& question, Pkt4Ptr& answer) {
     }
     // client-id is not mandatory in DHCPv4
 
-    IOAddress hint = question->getYiaddr();
+    // Try to get the Requested IP Address option and use the address as a hint
+    // for the allocation engine. If the server doesn't already have a lease
+    // for this client it will try to allocate the one requested.
+    OptionCustomPtr opt_requested_address = boost::dynamic_pointer_cast<
+        OptionCustom>(question->getOption(DHO_DHCP_REQUESTED_ADDRESS));
+    IOAddress hint("0.0.0.0");
+    if (opt_requested_address) {
+        hint = opt_requested_address->readAddress();
+    }
 
     HWAddrPtr hwaddr = question->getHWAddr();
 
@@ -1078,7 +1086,7 @@ Dhcpv4Srv::assignLease(const Pkt4Ptr& question, Pkt4Ptr& answer) {
 
     } else {
         // Allocation engine did not allocate a lease. The engine logged
-        // cause of that failure. The only thing left is to insert
+        // cause of that failure. The onlxy thing left is to insert
         // status code to pass the sad news to the client.
 
         LOG_DEBUG(dhcp4_logger, DBG_DHCP4_DETAIL, fake_allocation?

src/bin/dhcp4/tests/Makefile.am

@@ -90,6 +90,7 @@ dhcp4_unittests_SOURCES += fqdn_unittest.cc
 dhcp4_unittests_SOURCES += marker_file.cc
 dhcp4_unittests_SOURCES += dhcp4_client.cc dhcp4_client.h
 dhcp4_unittests_SOURCES += inform_unittest.cc
+dhcp4_unittests_SOURCES += dora_unittest.cc
 
 if CONFIG_BACKEND_BUNDY
 # For Bundy backend, we only need to run the usual tests. There are no

src/bin/dhcp4/tests/dhcp4_client.cc

@@ -21,6 +21,8 @@
 #include <boost/pointer_cast.hpp>
 #include <cstdlib>
 
+using namespace isc::asiolink;
+
 namespace isc {
 namespace dhcp {
 namespace test {
@@ -38,9 +40,10 @@ Dhcp4Client::Configuration::reset() {
     log_servers_.clear();
     quotes_servers_.clear();
     serverid_ = asiolink::IOAddress("0.0.0.0");
+    lease_ = Lease4();
 }
 
-Dhcp4Client::Dhcp4Client() :
+Dhcp4Client::Dhcp4Client(const Dhcp4Client::State& state) :
     config_(),
     curr_transid_(0),
     dest_addr_("255.255.255.255"),
@@ -49,10 +52,12 @@ Dhcp4Client::Dhcp4Client() :
     requested_options_(),
     server_facing_relay_addr_("10.0.0.2"),
     srv_(boost::shared_ptr<NakedDhcpv4Srv>(new NakedDhcpv4Srv(0))),
+    state_(state),
     use_relay_(false) {
 }
 
-Dhcp4Client::Dhcp4Client(boost::shared_ptr<NakedDhcpv4Srv>& srv) :
+Dhcp4Client::Dhcp4Client(boost::shared_ptr<NakedDhcpv4Srv>& srv,
+                         const Dhcp4Client::State& state) :
     config_(),
     curr_transid_(0),
     dest_addr_("255.255.255.255"),
@@ -61,6 +66,7 @@ Dhcp4Client::Dhcp4Client(boost::shared_ptr<NakedDhcpv4Srv>& srv) :
     requested_options_(),
     server_facing_relay_addr_("10.0.0.2"),
     srv_(srv),
+    state_(state),
     use_relay_(false) {
 }
 
@@ -104,7 +110,12 @@ Dhcp4Client::applyConfiguration() {
         config_.serverid_ = opt_serverid->readAddress();
     }
 
-    /// @todo Other possible configuration, e.g. lease.
+    /// @todo Set the valid lifetime, t1, t2 etc.
+    config_.lease_ = Lease4(IOAddress(context_.response_->getYiaddr()),
+                            &context_.response_->getHWAddr()->hwaddr_[0],
+                            context_.response_->getHWAddr()->hwaddr_.size(),
+                            0, 0, 0, 0, 0, time(NULL), 0, false, false,
+                            "");
 }
 
 void
@@ -124,20 +135,36 @@ Dhcp4Client::createMsg(const uint8_t msg_type) {
 }
 
 void
+Dhcp4Client::doDiscover(const boost::shared_ptr<IOAddress>& requested_addr) {
+    context_.query_ = createMsg(DHCPDISCOVER);
+    // Request options if any.
+    includePRL();
+    if (requested_addr) {
+        Option4AddrLstPtr
+            opt_requested_addr(new Option4AddrLst(DHO_DHCP_REQUESTED_ADDRESS,
+                                                  IOAddress(*requested_addr)));
+        context_.query_->addOption(opt_requested_addr);
+    }
+    // Send the message to the server.
+    sendMsg(context_.query_);
+    // Expect response.
+    context_.response_ = receiveOneMsg();
+}
+
+void
+Dhcp4Client::doDORA(const boost::shared_ptr<IOAddress>& requested_addr) {
+    doDiscover(requested_addr);
+    if (context_.response_ && (context_.response_->getType() == DHCPOFFER)) {
+        doRequest(requested_addr);
+    }
+}
+
+
+void
 Dhcp4Client::doInform(const bool set_ciaddr) {
     context_.query_ = createMsg(DHCPINFORM);
     // Request options if any.
-    if (!requested_options_.empty()) {
-        // Include Parameter Request List if at least one option code
-        // has been specified to be requested.
-        OptionUint8ArrayPtr prl(new OptionUint8Array(Option::V4,
-                                  DHO_DHCP_PARAMETER_REQUEST_LIST));
-        for (std::set<uint8_t>::const_iterator opt = requested_options_.begin();
-             opt != requested_options_.end(); ++opt) {
-            prl->addValue(*opt);
-        }
-        context_.query_->addOption(prl);
-    }
+    includePRL();
     // The client sending a DHCPINFORM message has an IP address obtained
     // by some other means, e.g. static configuration. The lease which we
     // are using here is most likely set by the createLease method.
@@ -159,6 +186,72 @@ Dhcp4Client::doInform(const bool set_ciaddr) {
     }
 }
 
+void
+Dhcp4Client::doRequest(const boost::shared_ptr<IOAddress>& requested_addr) {
+    context_.query_ = createMsg(DHCPREQUEST);
+
+    // Set ciaddr.
+    if ((state_ == SELECTING) || (state_ == INIT_REBOOT)) {
+        context_.query_->setCiaddr(IOAddress("0.0.0.0"));
+    } else {
+        context_.query_->setCiaddr(IOAddress(config_.lease_.addr_));
+    }
+
+    // Requested IP address.
+    if ((state_ == SELECTING) || (state_ == INIT_REBOOT)) {
+        if (context_.response_ &&
+            (context_.response_->getType() == DHCPOFFER) &&
+            (context_.response_->getYiaddr() != IOAddress("0.0.0.0"))) {
+            Option4AddrLstPtr
+                opt_requested_addr(new Option4AddrLst(DHO_DHCP_REQUESTED_ADDRESS,
+                                                      IOAddress(context_.response_->getYiaddr())));
+            context_.query_->addOption(opt_requested_addr);
+        } else {
+            isc_throw(Dhcp4ClientError, "error sending the DHCPREQUEST because"
+                      " the received DHCPOFFER message was invalid");
+        }
+    }
+
+    // Server identifier.
+    if (state_ == SELECTING) {
+        if (context_.response_) {
+            OptionPtr opt_serverid =
+                context_.response_->getOption(DHO_DHCP_SERVER_IDENTIFIER);
+            if (!opt_serverid) {
+                isc_throw(Dhcp4ClientError, "missing server identifier in the"
+                          " server's response");
+            }
+            context_.query_->addOption(opt_serverid);
+        }
+    }
+
+    // Request options if any.
+    includePRL();
+    // Send the message to the server.
+    sendMsg(context_.query_);
+    // Expect response.
+    context_.response_ = receiveOneMsg();
+    // If the server has responded, store the configuration received.
+    if (context_.response_) {
+        applyConfiguration();
+    }
+}
+
+void
+Dhcp4Client::includePRL() {
+    if (!requested_options_.empty() && context_.query_) {
+        // Include Parameter Request List if at least one option code
+        // has been specified to be requested.
+        OptionUint8ArrayPtr prl(new OptionUint8Array(Option::V4,
+                                  DHO_DHCP_PARAMETER_REQUEST_LIST));
+        for (std::set<uint8_t>::const_iterator opt = requested_options_.begin();
+             opt != requested_options_.end(); ++opt) {
+            prl->addValue(*opt);
+        }
+        context_.query_->addOption(prl);
+    }
+}
+
 HWAddrPtr
 Dhcp4Client::generateHWAddr(const uint8_t htype) const {
     if (htype != HTYPE_ETHER) {

src/bin/dhcp4/tests/dhcp4_client.h

@@ -27,6 +27,13 @@ namespace isc {
 namespace dhcp {
 namespace test {
 
+/// @brief General error emitted by the DHCP4 test client.
+class Dhcp4ClientError : public isc::Exception {
+public:
+    Dhcp4ClientError(const char* file, size_t line, const char* what) :
+        isc::Exception(file, line, what) { };
+};
+
 /// @brief DHCPv4 client used for unit testing.
 ///
 /// This class implements a DHCPv4 "client" which interoperates with the
@@ -45,6 +52,14 @@ namespace test {
 class Dhcp4Client : public boost::noncopyable {
 public:
 
+    /// @brief States of the DHCP client.
+    enum State {
+        SELECTING,
+        INIT_REBOOT,
+        RENEWING,
+        REBINDING
+    };
+
     /// @brief Holds the DHCPv4 messages taking part in transaction between
     /// the client and the server.
     struct Context {
@@ -79,12 +94,16 @@ public:
     };
 
     /// @brief Creates a new client.
-    Dhcp4Client();
+    ///
+    /// @param Initial client's state.
+    Dhcp4Client(const State& state = SELECTING);
 
     /// @brief Creates a new client that communicates with a specified server.
     ///
     /// @param srv An instance of the DHCPv4 server to be used.
-    Dhcp4Client(boost::shared_ptr<NakedDhcpv4Srv>& srv);
+    /// @param state Initial client's state.
+    Dhcp4Client(boost::shared_ptr<NakedDhcpv4Srv>& srv,
+                const State& state = SELECTING);
 
     /// @brief Creates a lease for the client using the specified address
     /// and valid lifetime.
@@ -101,6 +120,21 @@ public:
     /// @param valid_lft Valid lifetime.
     void createLease(const asiolink::IOAddress& addr, const uint32_t valid_lft);
 
+    /// @brief Sends DHCPDISCOVER message to the server and receives response.
+    ///
+    /// @param requested_addr A pointer to the IP Address to be sent in the
+    /// Requested IP Address option or NULL if the option should not be
+    /// included.
+    void doDiscover(const boost::shared_ptr<asiolink::IOAddress>&
+                    requested_addr = boost::shared_ptr<asiolink::IOAddress>());
+
+    /// @brief Perform 4-way exchange with a server.
+    ///
+    /// @param requested_addr A pointer to the address to be requested using the
+    /// Requested IP Address option.
+    void doDORA(const boost::shared_ptr<asiolink::IOAddress>&
+                requested_addr = boost::shared_ptr<asiolink::IOAddress>());
+
     /// @brief Sends DHCPINFORM message to the server and receives response.
     ///
     /// This function simulates sending the DHCPINFORM message to the server
@@ -121,6 +155,14 @@ public:
     /// an error occurs.
     void doInform(const bool set_ciaddr = true);
 
+    /// @brief Sends DHCPREQUEST Message to the server and receives a response.
+    ///
+    /// @param requested_addr A pointer to the IP Address to be sent in the
+    /// Requested IP Address option or NULL if the option should not be
+    /// included.
+    void doRequest(const boost::shared_ptr<asiolink::IOAddress>&
+                   requested_addr = boost::shared_ptr<asiolink::IOAddress>());
+
     /// @brief Generates a hardware address used by the client.
     ///
     /// It assigns random values to the bytes of the hardware address.
@@ -195,6 +237,16 @@ public:
         dest_addr_ = dest_addr;
     }
 
+    /// @brief Sets client state.
+    ///
+    /// Depending on the current state the client's behavior is different
+    /// when sending Request messages as per RFC2131, section 4.3.2.
+    ///
+    /// @param state New client's state.
+    void setState(const State& state) {
+        state_ = state;
+    }
+
     /// @brief Simulate sending messages through a relay.
     ///
     /// @param use Parameter which 'true' value indicates that client should
@@ -236,6 +288,13 @@ private:
     /// @return An instance of the message created.
     Pkt4Ptr createMsg(const uint8_t msg_type);
 
+    /// @brief Include PRL Option in the query message.
+    ///
+    /// This function creates the instance of the PRL option and adds
+    /// option codes from the @c requested_options_ to it. It later adds
+    /// the PRL option to the @c context_.query_ message if it is non-NULL.
+    void includePRL();
+
     /// @brief Simulates reception of the message from the server.
     ///
     /// @return Received message.
@@ -274,6 +333,9 @@ private:
     /// @brief Pointer to the server that the client is communicating with.
     boost::shared_ptr<NakedDhcpv4Srv> srv_;
 
+    /// @brief Current state of the client.
+    State state_;
+
     /// @brief Enable relaying messages to the server.
     bool use_relay_;
 };

src/bin/dhcp4/tests/dora_unittest.cc

@@ -0,0 +1,167 @@
+// Copyright (C) 2014 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 <asiolink/io_address.h>
+#include <cc/data.h>
+#include <dhcp/dhcp4.h>
+#include <dhcp/tests/iface_mgr_test_config.h>
+#include <dhcp4/tests/dhcp4_test_utils.h>
+#include <dhcp4/tests/dhcp4_client.h>
+#include <boost/shared_ptr.hpp>
+
+using namespace isc;
+using namespace isc::asiolink;
+using namespace isc::data;
+using namespace isc::dhcp;
+using namespace isc::dhcp::test;
+
+namespace {
+
+/// @brief Set of JSON configurations used throughout the DORA tests.
+///
+/// - Configuration 0:
+///   - Used for testing direct traffic
+///   - 1 subnet: 10.0.0.0/24
+///   - 1 pool: 10.0.0.10-10.0.0.100
+///   - Router option present: 10.0.0.200 and 10.0.0.201
+///   - Domain Name Server option present: 10.0.0.202, 10.0.0.203.
+///   - Log Servers option present: 192.0.2.200 and 192.0.2.201
+///   - Quotes Servers option present: 192.0.2.202, 192.0.2.203.
+///
+/// - Configuration 1:
+///   - Use for testing relayed messages
+///   - 1 subnet: 192.0.2.0/24
+///   - Router option present: 192.0.2.200 and 192.0.2.201
+///   - Domain Name Server option present: 192.0.2.202, 192.0.2.203.
+///   - Log Servers option present: 192.0.2.200 and 192.0.2.201
+///   - Quotes Servers option present: 192.0.2.202, 192.0.2.203.
+const char* DORA_CONFIGS[] = {
+// Configuration 0
+    "{ \"interfaces\": [ \"all\" ],"
+        "\"valid-lifetime\": 600,"
+        "\"subnet4\": [ { "
+        "    \"subnet\": \"10.0.0.0/24\", "
+        "    \"pool\": [ \"10.0.0.10-10.0.0.100\" ],"
+        "    \"option-data\": [ {"
+        "        \"name\": \"routers\","
+        "        \"code\": 3,"
+        "        \"data\": \"10.0.0.200,10.0.0.201\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    },"
+        "    {"
+        "        \"name\": \"domain-name-servers\","
+        "        \"code\": 6,"
+        "        \"data\": \"10.0.0.202,10.0.0.203\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    },"
+        "    {"
+        "        \"name\": \"log-servers\","
+        "        \"code\": 7,"
+        "        \"data\": \"10.0.0.200,10.0.0.201\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    },"
+        "    {"
+        "        \"name\": \"cookie-servers\","
+        "        \"code\": 8,"
+        "        \"data\": \"10.0.0.202,10.0.0.203\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    } ]"
+        " } ]"
+    "}",
+
+// Configuration 1
+    "{ \"interfaces\": [ \"all\" ],"
+        "\"valid-lifetime\": 600,"
+        "\"subnet4\": [ { "
+        "    \"subnet\": \"192.0.2.0/24\", "
+        "    \"option-data\": [ {"
+        "        \"name\": \"routers\","
+        "        \"code\": 3,"
+        "        \"data\": \"192.0.2.200,192.0.2.201\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    },"
+        "    {"
+        "        \"name\": \"domain-name-servers\","
+        "        \"code\": 6,"
+        "        \"data\": \"192.0.2.202,192.0.2.203\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    },"
+        "    {"
+        "        \"name\": \"log-servers\","
+        "        \"code\": 7,"
+        "        \"data\": \"10.0.0.200,10.0.0.201\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    },"
+        "    {"
+        "        \"name\": \"cookie-servers\","
+        "        \"code\": 8,"
+        "        \"data\": \"10.0.0.202,10.0.0.203\","
+        "        \"csv-format\": true,"
+        "        \"space\": \"dhcp4\""
+        "    } ]"
+        " } ]"
+    "}"
+};
+
+/// @brief Test fixture class for testing 4-way (DORA) exchanges.
+class DORATest : public Dhcpv4SrvTest {
+public:
+
+    /// @brief Constructor.
+    ///
+    /// Sets up fake interfaces.
+    DORATest()
+        : Dhcpv4SrvTest(),
+          iface_mgr_test_config_(true) {
+        IfaceMgr::instance().openSockets4();
+    }
+
+    /// @brief Interface Manager's fake configuration control.
+    IfaceMgrTestConfig iface_mgr_test_config_;
+
+};
+
+// This test verifies that the client in a SELECTING state can request
+// a specific address and that this address will be assigned when
+// available.
+TEST_F(DORATest, selectingRequestAvailableAddress) {
+    Dhcp4Client client(Dhcp4Client::SELECTING);
+    // Configure DHCP server.
+    configure(DORA_CONFIGS[0], *client.getServer());
+
+    // Perform 4-way exchange with the server.
+    ASSERT_NO_THROW(client.doDORA(boost::shared_ptr<IOAddress>(new IOAddress("10.0.0.50"))));
+
+    // Make sure that the server responded.
+    ASSERT_TRUE(client.getContext().response_);
+    Pkt4Ptr resp = client.getContext().response_;
+    // Make sure that the server has responded with DHCPACK.
+    ASSERT_EQ(DHCPACK, static_cast<int>(resp->getType()));
+    // Response must not be relayed.
+    EXPECT_FALSE(resp->isRelayed());
+    // Make sure that the server id is present.
+    EXPECT_EQ("10.0.0.1", client.config_.serverid_.toText());
+    // Make sure that the client has got the lease with the requested address.
+    EXPECT_EQ("10.0.0.50", client.config_.lease_.addr_.toText());
+}
+
+} // end of anonymous namespace

src/bin/dhcp4/tests/inform_unittest.cc

@@ -28,7 +28,7 @@ using namespace isc::dhcp::test;
 
 namespace {
 
-/// @brief Set of JSON configurations used throughout the Rebind tests.
+/// @brief Set of JSON configurations used throughout the Inform tests.
 ///
 /// - Configuration 0:
 ///   - Used for testing direct traffic