[#1139] Host based classes used in allocation

The change made for DHCPv6 server.

3 files changed, 196 insertions, 10 deletions

diff --git a/src/bin/dhcp6/dhcp6_srv.cc b/src/bin/dhcp6/dhcp6_srv.cc
index b3c1145b03..049f3329b8 100644
--- a/src/bin/dhcp6/dhcp6_srv.cc
+++ b/src/bin/dhcp6/dhcp6_srv.cc
@@ -424,6 +424,17 @@ Dhcpv6Srv::initContext(const Pkt6Ptr& pkt,
         alloc_engine_->findReservation(ctx);
     }
 
+    // Global host reservations are independent of a selected subnet. If the
+    // global reservations contain client classes we should use them in case
+    // they are meant to affect pool selection.
+    auto global_host = ctx.globalHost();
+    if (global_host && !global_host->getClientClasses6().empty()) {
+        // Previously evaluated classes must be ignored because having new
+        // classes fetched from the hosts db may eliminate some of them.
+        pkt->classes_.clear();
+        setReservedClientClasses(pkt, ctx);
+    }
+
     // Set KNOWN builtin class if something was found, UNKNOWN if not.
     if (!ctx.hosts_.empty()) {
         pkt->addClass("KNOWN");
@@ -2979,7 +2990,7 @@ Dhcpv6Srv::processSolicit(AllocEngine::ClientContext6& ctx) {
     processClientFqdn(solicit, response, ctx);
     assignLeases(solicit, response, ctx);
 
-    setReservedClientClasses(solicit, ctx);
+    setNonGlobalReservedClientClasses(solicit, ctx);
     requiredClassify(solicit, ctx);
 
     copyClientOptions(solicit, response);
@@ -3009,7 +3020,7 @@ Dhcpv6Srv::processRequest(AllocEngine::ClientContext6& ctx) {
     processClientFqdn(request, reply, ctx);
     assignLeases(request, reply, ctx);
 
-    setReservedClientClasses(request, ctx);
+    setNonGlobalReservedClientClasses(request, ctx);
     requiredClassify(request, ctx);
 
     copyClientOptions(request, reply);
@@ -3035,7 +3046,7 @@ Dhcpv6Srv::processRenew(AllocEngine::ClientContext6& ctx) {
     processClientFqdn(renew, reply, ctx);
     extendLeases(renew, reply, ctx);
 
-    setReservedClientClasses(renew, ctx);
+    setNonGlobalReservedClientClasses(renew, ctx);
     requiredClassify(renew, ctx);
 
     copyClientOptions(renew, reply);
@@ -3061,7 +3072,7 @@ Dhcpv6Srv::processRebind(AllocEngine::ClientContext6& ctx) {
     processClientFqdn(rebind, reply, ctx);
     extendLeases(rebind, reply, ctx);
 
-    setReservedClientClasses(rebind, ctx);
+    setNonGlobalReservedClientClasses(rebind, ctx);
     requiredClassify(rebind, ctx);
 
     copyClientOptions(rebind, reply);
@@ -3082,7 +3093,7 @@ Pkt6Ptr
 Dhcpv6Srv::processConfirm(AllocEngine::ClientContext6& ctx) {
 
     Pkt6Ptr confirm = ctx.query_;
-    setReservedClientClasses(confirm, ctx);
+    setNonGlobalReservedClientClasses(confirm, ctx);
     requiredClassify(confirm, ctx);
 
     // Get IA_NAs from the Confirm. If there are none, the message is
@@ -3172,7 +3183,7 @@ Pkt6Ptr
 Dhcpv6Srv::processRelease(AllocEngine::ClientContext6& ctx) {
 
     Pkt6Ptr release = ctx.query_;
-    setReservedClientClasses(release, ctx);
+    setNonGlobalReservedClientClasses(release, ctx);
     requiredClassify(release, ctx);
 
     // Create an empty Reply message.
@@ -3198,7 +3209,7 @@ Pkt6Ptr
 Dhcpv6Srv::processDecline(AllocEngine::ClientContext6& ctx) {
 
     Pkt6Ptr decline = ctx.query_;
-    setReservedClientClasses(decline, ctx);
+    setNonGlobalReservedClientClasses(decline, ctx);
     requiredClassify(decline, ctx);
 
     // Create an empty Reply message.
@@ -3493,7 +3504,7 @@ Pkt6Ptr
 Dhcpv6Srv::processInfRequest(AllocEngine::ClientContext6& ctx) {
 
     Pkt6Ptr inf_request = ctx.query_;
-    setReservedClientClasses(inf_request, ctx);
+    setNonGlobalReservedClientClasses(inf_request, ctx);
     requiredClassify(inf_request, ctx);
 
     // Create a Reply packet, with the same trans-id as the client's.
@@ -3645,6 +3656,14 @@ Dhcpv6Srv::setReservedClientClasses(const Pkt6Ptr& pkt,
 }
 
 void
+Dhcpv6Srv::setNonGlobalReservedClientClasses(const Pkt6Ptr& pkt,
+                                             const AllocEngine::ClientContext6& ctx) {
+    if (!ctx.globalHost()) {
+        setReservedClientClasses(pkt, ctx);
+    }
+}
+
+void
 Dhcpv6Srv::requiredClassify(const Pkt6Ptr& pkt, AllocEngine::ClientContext6& ctx) {
     // First collect required classes
     ClientClasses classes = pkt->getClasses(true);
diff --git a/src/bin/dhcp6/dhcp6_srv.h b/src/bin/dhcp6/dhcp6_srv.h
index b1716340ac..c2a4943b6c 100644
--- a/src/bin/dhcp6/dhcp6_srv.h
+++ b/src/bin/dhcp6/dhcp6_srv.h
@@ -821,6 +821,14 @@ protected:
     void setReservedClientClasses(const Pkt6Ptr& pkt,
                                   const AllocEngine::ClientContext6& ctx);
 
+    /// @brief Assigns non-global classes retrieved from host reservation
+    /// database.
+    ///
+    /// @param pkt Pointer to the packet to which classes will be assigned.
+    /// @param ctx Reference to the client context.
+    void setNonGlobalReservedClientClasses(const Pkt6Ptr& pkt,
+                                           const AllocEngine::ClientContext6& ctx);
+
     /// @brief Assigns incoming packet to zero or more classes (required pass).
     ///
     /// @note This required classification evaluates all classes which
diff --git a/src/bin/dhcp6/tests/host_unittest.cc b/src/bin/dhcp6/tests/host_unittest.cc
index 596470f4c7..d6905ab60f 100644
--- a/src/bin/dhcp6/tests/host_unittest.cc
+++ b/src/bin/dhcp6/tests/host_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2015-2018 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2015-2020 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
@@ -419,7 +419,111 @@ const char* CONFIGS[] = {
         "    }] \n"
         " }"
         " ] \n"
-    "} \n"
+    "} \n",
+
+    // Configuration 10: client-class reservation in global, shared network
+    // and client-class guarded pools.
+    "{ \"interfaces-config\": {\n"
+        "      \"interfaces\": [ \"*\" ]\n"
+        "},\n"
+        "\"host-reservation-identifiers\": [ \"duid\", \"hw-address\" ], \n"
+        "\"client-classes\": ["
+        "{"
+        "     \"name\": \"reserved_class\""
+        "},"
+        "{"
+        "     \"name\": \"unreserved_class\","
+        "     \"test\": \"not member('reserved_class')\""
+        "}"
+        "],\n"
+        "\"reservation-mode\": \"global\","
+        "\"valid-lifetime\": 4000,\n"
+        "\"reservations\": [ \n"
+        "{\n"
+        "   \"duid\": \"01:02:03:05\",\n"
+        "   \"client-classes\": [ \"reserved_class\" ]\n"
+        "}\n"
+        "],\n"
+        "\"shared-networks\": [{"
+        "    \"name\": \"frog\",\n"
+        "    \"subnet6\": [\n"
+        "        {\n"
+        "            \"subnet\": \"2001:db8:1::/64\", \n"
+        "            \"id\": 10,"
+        "            \"pools\": ["
+        "                {"
+        "                    \"pool\": \"2001:db8:1::10-2001:db8:1::11\","
+        "                    \"client-class\": \"reserved_class\""
+        "                }"
+        "            ],\n"
+        "            \"interface\": \"eth0\"\n"
+        "        },\n"
+        "        {\n"
+        "            \"subnet\": \"2001:db8:2::/64\", \n"
+        "            \"id\": 11,"
+        "            \"pools\": ["
+        "                {"
+        "                    \"pool\": \"2001:db8:2::10-2001:db8:2::11\","
+        "                    \"client-class\": \"unreserved_class\""
+        "                }"
+        "            ],\n"
+        "            \"interface\": \"eth0\"\n"
+        "        }\n"
+        "    ]\n"
+        "}]\n"
+    "}",
+
+    // Configuration 11: client-class reservation in global, shared network
+    // and client-class guarded subnets.
+    "{ \"interfaces-config\": {\n"
+        "      \"interfaces\": [ \"*\" ]\n"
+        "},\n"
+        "\"host-reservation-identifiers\": [ \"duid\", \"hw-address\" ], \n"
+        "\"client-classes\": ["
+        "{"
+        "     \"name\": \"reserved_class\""
+        "},"
+        "{"
+        "     \"name\": \"unreserved_class\","
+        "     \"test\": \"not member('reserved_class')\""
+        "}"
+        "],\n"
+        "\"reservation-mode\": \"global\","
+        "\"valid-lifetime\": 4000,\n"
+        "\"reservations\": [ \n"
+        "{\n"
+        "   \"duid\": \"01:02:03:05\",\n"
+        "   \"client-classes\": [ \"reserved_class\" ]\n"
+        "}\n"
+        "],\n"
+    "\"shared-networks\": [{"
+        "    \"name\": \"frog\",\n"
+        "    \"subnet6\": [\n"
+        "        {\n"
+        "            \"subnet\": \"2001:db8:1::/64\", \n"
+        "            \"client-class\": \"reserved_class\","
+        "            \"id\": 10,"
+        "            \"pools\": ["
+        "                {"
+        "                    \"pool\": \"2001:db8:1::10-2001:db8:1::11\""
+        "                }"
+        "            ],\n"
+        "            \"interface\": \"eth0\"\n"
+        "        },\n"
+        "        {\n"
+        "            \"subnet\": \"2001:db8:2::/64\", \n"
+        "            \"client-class\": \"unreserved_class\","
+        "            \"id\": 11,"
+        "            \"pools\": ["
+        "                {"
+        "                    \"pool\": \"2001:db8:2::10-2001:db8:2::11\""
+        "                }"
+        "            ],\n"
+        "            \"interface\": \"eth0\"\n"
+        "        }\n"
+        "    ]\n"
+        "}]\n"
+    "}"
 };
 
 /// @brief Base class representing leases and hints conveyed within IAs.
@@ -813,6 +917,15 @@ public:
     /// @param hint Const reference to an object holding the hint.
     static void requestIA(Dhcp6Client& client, const Hint& hint);
 
+    /// @brief Test pool or subnet selection using global class reservation.
+    ///
+    /// Verifies that client class specified in the global reservation
+    /// may be used to influence pool or subnet selection.
+    ///
+    /// @param config_idx Index of the server configuration from the
+    /// @c CONFIGS array.
+    void testGlobalClassSubnetPoolSelection(const int config_idx);
+
     /// @brief Configures client to include 6 IAs without hints.
     ///
     /// This method configures the client to include 3 IA_NAs and
@@ -1159,6 +1272,40 @@ HostTest::testOverrideVendorOptions(const uint16_t msg_type) {
 }
 
 void
+HostTest::testGlobalClassSubnetPoolSelection(const int config_idx) {
+    Dhcp6Client client_resrv;
+
+    // Use DUID for which we have host reservation including client class.
+    client_resrv.setDUID("01:02:03:05");
+
+    ASSERT_NO_FATAL_FAILURE(configure(CONFIGS[config_idx], *client_resrv.getServer()));
+
+    // This client should be given an address from the 2001:db8:1::/64 subnet.
+    // Let's use the 2001:db8:2::10 as a hint to make sure that the server
+    // refuses allocating it and uses the sole pool available for this
+    // client.
+    client_resrv.requestAddress(1, IOAddress("2001:db8:2::10"));
+    ASSERT_NO_THROW(client_resrv.doSARR());
+    ASSERT_EQ(1, client_resrv.getLeaseNum());
+    Lease6 lease_client = client_resrv.getLease(0);
+    EXPECT_EQ("2001:db8:1::10", lease_client.addr_.toText());
+
+    // This client has no reservation and therefore should be
+    // assigned to the unreserved_class and be given an address
+    // from the other pool.
+    Dhcp6Client client_no_resrv(client_resrv.getServer());
+    client_no_resrv.setDUID("01:02:03:04");
+
+    // Let's use the address of 2001:db8:1::10 as a hint to make sure that the
+    // server refuses it in favor of the 2001:db8:2::10.
+    client_no_resrv.requestAddress(1, IOAddress("2001:db8:1::10"));
+    ASSERT_NO_THROW(client_no_resrv.doSARR());
+    ASSERT_EQ(1, client_no_resrv.getLeaseNum());
+    lease_client = client_no_resrv.getLease(0);
+    EXPECT_EQ("2001:db8:2::10", lease_client.addr_.toText());
+}
+
+void
 HostTest::requestEmptyIAs(Dhcp6Client& client) {
     // Create IAs with IAIDs between 1 and 6.
     client.requestAddress(1);
@@ -2147,4 +2294,16 @@ TEST_F(HostTest, globalReservationsPD) {
     }
 }
 
+// Verifies that client class specified in the global reservation
+// may be used to influence pool selection.
+TEST_F(HostTest, clientClassGlobalPoolSelection) {
+    ASSERT_NO_FATAL_FAILURE(testGlobalClassSubnetPoolSelection(10));
+}
+
+// Verifies that client class specified in the global reservation
+// may be used to influence subnet selection within shared network.
+TEST_F(HostTest, clientClassGlobalSubnetSelection) {
+    ASSERT_NO_FATAL_FAILURE(testGlobalClassSubnetPoolSelection(11));
+}
+
 } // end of anonymous namespace