[3281] DHCPv4 configuration parser sets the subnet id specified by user.

src/bin/dhcp4/config_parser.cc

@@ -201,7 +201,8 @@ protected:
         DhcpConfigParser* parser = NULL;
         if ((config_id.compare("valid-lifetime") == 0)  ||
             (config_id.compare("renew-timer") == 0)  ||
-            (config_id.compare("rebind-timer") == 0))  {
+            (config_id.compare("rebind-timer") == 0) ||
+            (config_id.compare("id") == 0)) {
             parser = new Uint32Parser(config_id, uint32_values_);
         } else if ((config_id.compare("subnet") == 0) ||
                    (config_id.compare("interface") == 0) ||
@@ -271,6 +272,10 @@ protected:
         Triplet<uint32_t> t1 = getParam("renew-timer");
         Triplet<uint32_t> t2 = getParam("rebind-timer");
         Triplet<uint32_t> valid = getParam("valid-lifetime");
+        // Subnet ID is optional. If it is not supplied the value of 0 is used,
+        // which means autogenerate.
+        SubnetID subnet_id =
+            static_cast<SubnetID>(uint32_values_->getOptionalParam("id", 0));
 
         stringstream tmp;
         tmp << addr << "/" << (int)len
@@ -278,7 +283,7 @@ protected:
 
         LOG_INFO(dhcp4_logger, DHCP4_CONFIG_NEW_SUBNET).arg(tmp.str());
 
-        Subnet4Ptr subnet4(new Subnet4(addr, len, t1, t2, valid));
+        Subnet4Ptr subnet4(new Subnet4(addr, len, t1, t2, valid, subnet_id));
         subnet_ = subnet4;
 
         // Try global value first

src/bin/dhcp4/dhcp4.spec

@@ -213,6 +213,12 @@
                   "item_default": ""
                 },
 
+                { "item_name": "id",
+                  "item_type": "integer",
+                  "item_optional": false,
+                  "item_default": 0
+                },
+
                 { "item_name": "renew-timer",
                   "item_type": "integer",
                   "item_optional": false,

src/bin/dhcp4/tests/config_parser_unittest.cc

@@ -550,6 +550,8 @@ TEST_F(Dhcp4ParserTest, subnetGlobalDefaults) {
 // multiple times.
 TEST_F(Dhcp4ParserTest, multipleSubnets) {
     ConstElementPtr x;
+    // Collection of four subnets for which subnet ids should be
+    // autogenerated - ids are unspecified or set to 0.
     string config = "{ \"interfaces\": [ \"*\" ],"
         "\"rebind-timer\": 2000, "
         "\"renew-timer\": 1000, "
@@ -559,7 +561,8 @@ TEST_F(Dhcp4ParserTest, multipleSubnets) {
         " },"
         " {"
         "    \"pool\": [ \"192.0.3.101 - 192.0.3.150\" ],"
-        "    \"subnet\": \"192.0.3.0/24\" "
+        "    \"subnet\": \"192.0.3.0/24\", "
+        "    \"id\": 0 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.4.101 - 192.0.4.150\" ],"
@@ -605,6 +608,106 @@ TEST_F(Dhcp4ParserTest, multipleSubnets) {
     } while (++cnt < 10);
 }
 
+// This test checks that it is possible to assign arbitrary ids for subnets.
+TEST_F(Dhcp4ParserTest, multipleSubnetsExplicitIDs) {
+    ConstElementPtr x;
+    // Collection of four subnets for which subnet ids should be
+    // autogenerated - ids are unspecified or set to 0.
+    string config = "{ \"interfaces\": [ \"*\" ],"
+        "\"rebind-timer\": 2000, "
+        "\"renew-timer\": 1000, "
+        "\"subnet4\": [ { "
+        "    \"pool\": [ \"192.0.2.1 - 192.0.2.100\" ],"
+        "    \"subnet\": \"192.0.2.0/24\", "
+        "    \"id\": 1024 "
+        " },"
+        " {"
+        "    \"pool\": [ \"192.0.3.101 - 192.0.3.150\" ],"
+        "    \"subnet\": \"192.0.3.0/24\", "
+        "    \"id\": 100 "
+        " },"
+        " {"
+        "    \"pool\": [ \"192.0.4.101 - 192.0.4.150\" ],"
+        "    \"subnet\": \"192.0.4.0/24\", "
+        "    \"id\": 1 "
+        " },"
+        " {"
+        "    \"pool\": [ \"192.0.5.101 - 192.0.5.150\" ],"
+        "    \"subnet\": \"192.0.5.0/24\", "
+        "    \"id\": 34 "
+        " } ],"
+        "\"valid-lifetime\": 4000 }";
+
+    ElementPtr json = Element::fromJSON(config);
+
+    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
+    ASSERT_TRUE(x);
+    comment_ = parseAnswer(rcode_, x);
+    ASSERT_EQ(0, rcode_);
+
+    int cnt = 0; // Number of reconfigurations
+
+    do {
+        ElementPtr json = Element::fromJSON(config);
+
+        EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
+        ASSERT_TRUE(x);
+        comment_ = parseAnswer(rcode_, x);
+        ASSERT_EQ(0, rcode_);
+
+        const Subnet4Collection* subnets = CfgMgr::instance().getSubnets4();
+        ASSERT_TRUE(subnets);
+        ASSERT_EQ(4, subnets->size()); // We expect 4 subnets
+
+        // Verify that subnet ids are as expected.
+        EXPECT_EQ(1024, subnets->at(0)->getID());
+        EXPECT_EQ(100, subnets->at(1)->getID());
+        EXPECT_EQ(1, subnets->at(2)->getID());
+        EXPECT_EQ(34, subnets->at(3)->getID());
+
+        // Repeat reconfiguration process 10 times and check that the subnet-id
+        // is set to the same value.
+    } while (++cnt < 10);
+}
+
+// Check that the configuration with two subnets having the same id is rejected.
+TEST_F(Dhcp4ParserTest, multipleSubnetsOverlapingIDs) {
+    ConstElementPtr x;
+    // Collection of four subnets for which subnet ids should be
+    // autogenerated - ids are unspecified or set to 0.
+    string config = "{ \"interfaces\": [ \"*\" ],"
+        "\"rebind-timer\": 2000, "
+        "\"renew-timer\": 1000, "
+        "\"subnet4\": [ { "
+        "    \"pool\": [ \"192.0.2.1 - 192.0.2.100\" ],"
+        "    \"subnet\": \"192.0.2.0/24\", "
+        "    \"id\": 1024 "
+        " },"
+        " {"
+        "    \"pool\": [ \"192.0.3.101 - 192.0.3.150\" ],"
+        "    \"subnet\": \"192.0.3.0/24\", "
+        "    \"id\": 100 "
+        " },"
+        " {"
+        "    \"pool\": [ \"192.0.4.101 - 192.0.4.150\" ],"
+        "    \"subnet\": \"192.0.4.0/24\", "
+        "    \"id\": 1024 "
+        " },"
+        " {"
+        "    \"pool\": [ \"192.0.5.101 - 192.0.5.150\" ],"
+        "    \"subnet\": \"192.0.5.0/24\", "
+        "    \"id\": 34 "
+        " } ],"
+        "\"valid-lifetime\": 4000 }";
+
+    ElementPtr json = Element::fromJSON(config);
+
+    EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
+    ASSERT_TRUE(x);
+    comment_ = parseAnswer(rcode_, x);
+    EXPECT_NE(rcode_, 0);
+}
+
 // Goal of this test is to verify that a previously configured subnet can be
 // deleted in subsequent reconfiguration.
 TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
@@ -616,19 +719,23 @@ TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
         "\"renew-timer\": 1000, "
         "\"subnet4\": [ { "
         "    \"pool\": [ \"192.0.2.1 - 192.0.2.100\" ],"
-        "    \"subnet\": \"192.0.2.0/24\" "
+        "    \"subnet\": \"192.0.2.0/24\", "
+        "    \"id\": 1 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.3.101 - 192.0.3.150\" ],"
-        "    \"subnet\": \"192.0.3.0/24\" "
+        "    \"subnet\": \"192.0.3.0/24\", "
+        "    \"id\": 2 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.4.101 - 192.0.4.150\" ],"
-        "    \"subnet\": \"192.0.4.0/24\" "
+        "    \"subnet\": \"192.0.4.0/24\", "
+        "    \"id\": 3 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.5.101 - 192.0.5.150\" ],"
-        "    \"subnet\": \"192.0.5.0/24\" "
+        "    \"subnet\": \"192.0.5.0/24\", "
+        "    \"id\": 4 "
         " } ],"
         "\"valid-lifetime\": 4000 }";
 
@@ -638,15 +745,18 @@ TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
         "\"renew-timer\": 1000, "
         "\"subnet4\": [ { "
         "    \"pool\": [ \"192.0.2.1 - 192.0.2.100\" ],"
-        "    \"subnet\": \"192.0.2.0/24\" "
+        "    \"subnet\": \"192.0.2.0/24\", "
+        "    \"id\": 1 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.3.101 - 192.0.3.150\" ],"
-        "    \"subnet\": \"192.0.3.0/24\" "
+        "    \"subnet\": \"192.0.3.0/24\", "
+        "    \"id\": 2 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.4.101 - 192.0.4.150\" ],"
-        "    \"subnet\": \"192.0.4.0/24\" "
+        "    \"subnet\": \"192.0.4.0/24\", "
+        "    \"id\": 3 "
         " } ],"
         "\"valid-lifetime\": 4000 }";
 
@@ -656,15 +766,18 @@ TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
         "\"renew-timer\": 1000, "
         "\"subnet4\": [ { "
         "    \"pool\": [ \"192.0.2.1 - 192.0.2.100\" ],"
-        "    \"subnet\": \"192.0.2.0/24\" "
+        "    \"subnet\": \"192.0.2.0/24\", "
+        "    \"id\": 1 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.4.101 - 192.0.4.150\" ],"
-        "    \"subnet\": \"192.0.4.0/24\" "
+        "    \"subnet\": \"192.0.4.0/24\", "
+        "    \"id\": 3 "
         " },"
         " {"
         "    \"pool\": [ \"192.0.5.101 - 192.0.5.150\" ],"
-        "    \"subnet\": \"192.0.5.0/24\" "
+        "    \"subnet\": \"192.0.5.0/24\", "
+        "    \"id\": 4 "
         " } ],"
         "\"valid-lifetime\": 4000 }";
 
@@ -700,7 +813,6 @@ TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
     /// CASE 2: Configure 4 subnets, then reconfigure and remove one
     /// from in between (not first, not last)
 
-#if 0
     /// @todo: Uncomment subnet removal test as part of #3281.
     json = Element::fromJSON(config4);
     EXPECT_NO_THROW(x = configureDhcp4Server(*srv_, json));
@@ -723,7 +835,6 @@ TEST_F(Dhcp4ParserTest, reconfigureRemoveSubnet) {
     // The second subnet (with subnet-id = 2) is no longer there
     EXPECT_EQ(3, subnets->at(1)->getID());
     EXPECT_EQ(4, subnets->at(2)->getID());
-#endif
 
 }