[2544] Added basic unit test for options parser.

src/bin/dhcp4/tests/config_parser_unittest.cc

@@ -1,3 +1,4 @@
+
 // Copyright (C) 2012 Internet Systems Consortium, Inc. ("ISC")
 //
 // Permission to use, copy, modify, and/or distribute this software for any
@@ -76,6 +77,46 @@ public:
         delete srv_;
     };
 
+    /// @brief Test option against given code and data.
+    ///
+    /// @param option_desc option descriptor that carries the option to
+    /// be tested.
+    /// @param expected_code expected code of the option.
+    /// @param expected_data expected data in the option.
+    /// @param expected_data_len length of the reference data.
+    /// @param extra_data if true extra data is allowed in an option
+    /// after tested data.
+    void testOption(const Subnet::OptionDescriptor& option_desc,
+                    uint16_t expected_code, const uint8_t* expected_data,
+                    size_t expected_data_len,
+                    bool extra_data = false) {
+        // Check if option descriptor contains valid option pointer.
+        ASSERT_TRUE(option_desc.option);
+        // Verify option type.
+        EXPECT_EQ(expected_code, option_desc.option->getType());
+        // We may have many different option types being created. Some of them
+        // have dedicated classes derived from Option class. In such case if
+        // we want to verify the option contents against expected_data we have
+        // to prepare raw buffer with the contents of the option. The easiest
+        // way is to call pack() which will prepare on-wire data.
+        util::OutputBuffer buf(option_desc.option->getData().size());
+        option_desc.option->pack(buf);
+        if (extra_data) {
+            // The length of the buffer must be at least equal to size of the
+            // reference data but it can sometimes be greater than that. This is
+            // because some options carry suboptions that increase the overall
+            // length.
+            ASSERT_GE(buf.getLength() - option_desc.option->getHeaderLen(),
+                      expected_data_len);
+        } else {
+            ASSERT_EQ(buf.getLength() - option_desc.option->getHeaderLen(),
+                      expected_data_len);
+        }
+        // Verify that the data is correct. However do not verify suboptions.
+        const uint8_t* data = static_cast<const uint8_t*>(buf.getData());
+        EXPECT_TRUE(memcmp(expected_data, data, expected_data_len));
+    }
+
     Dhcpv4Srv* srv_;
 
     int rcode_;
@@ -248,6 +289,75 @@ TEST_F(Dhcp4ParserTest, poolPrefixLen) {
     EXPECT_EQ(4000, subnet->getValid());
 }
 
+// Goal of this test is to verify that global option
+// data is configured for the subnet if the subnet
+// configuration does not include options configuration.
+TEST_F(Dhcp4ParserTest, optionDataDefaults) {
+    ConstElementPtr x;
+    string config = "{ \"interface\": [ \"all\" ],"
+        "\"rebind-timer\": 2000,"
+        "\"renew-timer\": 1000,"
+        "\"option-data\": [ {"
+        "    \"name\": \"option_foo\","
+        "    \"code\": 100,"
+        "    \"data\": \"AB CDEF0105\""
+        " },"
+        " {"
+        "    \"name\": \"option_foo2\","
+        "    \"code\": 101,"
+        "    \"data\": \"01\""
+        " } ],"
+        "\"subnet4\": [ { "
+        "    \"pool\": [ \"192.0.2.1 - 192.0.2.100\" ],"
+        "    \"subnet\": \"192.0.2.0/24\""
+        " } ],"
+        "\"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_);
+
+    Subnet4Ptr subnet = CfgMgr::instance().getSubnet4(IOAddress("192.0.2.200"));
+    ASSERT_TRUE(subnet);
+    const Subnet::OptionContainer& options = subnet->getOptions();
+    ASSERT_EQ(2, options.size());
+
+    // Get the search index. Index #1 is to search using option code.
+    const Subnet::OptionContainerTypeIndex& idx = options.get<1>();
+
+    // Get the options for specified index. Expecting one option to be
+    // returned but in theory we may have multiple options with the same
+    // code so we get the range.
+    std::pair<Subnet::OptionContainerTypeIndex::const_iterator,
+              Subnet::OptionContainerTypeIndex::const_iterator> range =
+        idx.equal_range(100);
+    // Expect single option with the code equal to 100.
+    ASSERT_EQ(1, std::distance(range.first, range.second));
+    const uint8_t foo_expected[] = {
+        0xAB, 0xCD, 0xEF, 0x01, 0x05
+    };
+    // Check if option is valid in terms of code and carried data.
+    testOption(*range.first, 100, foo_expected, sizeof(foo_expected));
+
+    range = idx.equal_range(101);
+    ASSERT_EQ(1, std::distance(range.first, range.second));
+    // Do another round of testing with second option.
+    const uint8_t foo2_expected[] = {
+        0x01
+    };
+    testOption(*range.first, 101, foo2_expected, sizeof(foo2_expected));
+
+    // Check that options with other option codes are not returned.
+    for (uint16_t code = 102; code < 110; ++code) {
+        range = idx.equal_range(code);
+        EXPECT_EQ(0, std::distance(range.first, range.second));
+    }
+}
+
+
 /// This test checks if Uint32Parser can really parse the whole range
 /// and properly err of out of range values. As we can't call Uint32Parser
 /// directly, we are exploiting the fact that it is used to parse global