1 files changed, 170 insertions, 0 deletions
diff --git a/src/lib/dhcp/tests/option6_pdexclude_unittest.cc b/src/lib/dhcp/tests/option6_pdexclude_unittest.cc
new file mode 100644
index 0000000..b119fc2
--- /dev/null
+++ b/src/lib/dhcp/tests/option6_pdexclude_unittest.cc
@@ -0,0 +1,170 @@
+// Copyright (C) 2016-2023 Internet Systems Consortium, Inc. ("ISC")
+//
+// Author: Andrei Pavel <andrei.pavel@qualitance.com>
+//
+// 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 <exceptions/exceptions.h>
+#include <dhcp/option6_pdexclude.h>
+#include <util/buffer.h>
+#include <util/encode/hex.h>
+#include <gtest/gtest.h>
+
+using namespace isc;
+using namespace isc::dhcp;
+using namespace asiolink;
+
+namespace {
+
+// Prefix constants used in unit tests.
+const IOAddress v4("192.0.2.0");
+const IOAddress bee0("2001:db8:dead:bee0::");
+const IOAddress beef("2001:db8:dead:beef::");
+const IOAddress cafe("2001:db8:dead:cafe::");
+const IOAddress beef01("2001:db8:dead:beef::01");
+
+// This test verifies that the constructor sets parameters appropriately.
+TEST(Option6PDExcludeTest, constructor) {
+    Option6PDExclude option = Option6PDExclude(beef, 56, beef01, 60);
+
+    EXPECT_EQ(bee0, option.getExcludedPrefix(beef, 56));
+    EXPECT_EQ(60, option.getExcludedPrefixLength());
+    EXPECT_EQ("E0", util::encode::encodeHex(option.getExcludedPrefixSubnetID()));
+
+    // Total length is a sum of option header length, excluded prefix
+    // length (always 1 byte) and delegated prefix length - excluded prefix
+    // length rounded to bytes.
+    EXPECT_EQ(Option::OPTION6_HDR_LEN + 1 + 1, option.len());
+
+    // v4 prefix is not accepted.
+    EXPECT_THROW(Option6PDExclude(v4, 56, beef01, 64), BadValue);
+    EXPECT_THROW(Option6PDExclude(beef, 56, v4, 64), BadValue);
+    // Length greater than 128 is not accepted.
+    EXPECT_THROW(Option6PDExclude(beef, 128, beef01, 129), BadValue);
+    // Excluded prefix length must be greater than delegated prefix length.
+    EXPECT_THROW(Option6PDExclude(beef, 56, beef01, 56), BadValue);
+    // Both prefixes shifted by 56 must be equal (see RFC6603, section 4.2).
+    EXPECT_THROW(Option6PDExclude(cafe, 56, beef01, 64), BadValue);
+}
+
+// This test verifies that on-wire format of the Prefix Exclude option is
+// created properly.
+TEST(Option6PDExcludeTest, pack) {
+    // Expected wire format of the option.
+    const uint8_t expected_data[] = {
+        0x00, 0x43, // option code 67
+        0x00, 0x02, // option length 2
+        0x3F, 0x70  // excluded prefix length 63 + subnet id
+    };
+    std::vector<uint8_t> expected_vec(expected_data,
+                                      expected_data + sizeof(expected_data));
+    // Generate wire format of the option.
+    util::OutputBuffer buf(128);
+    Option6PDExcludePtr option;
+    ASSERT_NO_THROW(option.reset(new Option6PDExclude(IOAddress("2001:db8:dead:bee0::"),
+                                                      59,
+                                                      IOAddress("2001:db8:dead:beef::"),
+                                                      63)));
+    ASSERT_NO_THROW(option->pack(buf));
+
+    // Check that size matches.
+    ASSERT_EQ(expected_vec.size(), buf.getLength());
+
+    // Check that the generated wire format is correct.
+    const uint8_t* data = static_cast<const uint8_t*>(buf.getData());
+    std::vector<uint8_t> vec(data, data + buf.getLength());
+    ASSERT_TRUE(std::equal(vec.begin(), vec.end(), expected_vec.begin()));
+}
+
+// This test verifies parsing option wire format with subnet id of
+// 1 byte.
+TEST(Option6PDExcludeTest, unpack1ByteSubnetId) {
+    const uint8_t data[] = {
+        0x00, 0x43, // option code 67
+        0x00, 0x02, // option length 2
+        0x40, 0x78  // excluded prefix length 60 + subnet id
+    };
+    std::vector<uint8_t> vec(data, data + sizeof(data));
+
+    // Parse option.
+    Option6PDExcludePtr option;
+    ASSERT_NO_THROW(
+        option.reset(new Option6PDExclude(vec.begin() + 4, vec.end()))
+    );
+
+    // Make sure that the option has been parsed correctly.
+    EXPECT_EQ("2001:db8:dead:beef::",
+              option->getExcludedPrefix(IOAddress("2001:db8:dead:bee0::1"), 59).toText());
+    EXPECT_EQ(64, static_cast<int>(option->getExcludedPrefixLength()));
+}
+
+// This test verifies parsing option wire format with subnet id of
+// 2 bytes.
+TEST(Option6PDExcludeTest, unpack2ByteSubnetId) {
+    const uint8_t data[] = {
+        0x00, 0x43,       // option code 67
+        0x00, 0x02,       // option length
+        0x40, 0xbe, 0xef  // excluded prefix length 60 + subnet id
+    };
+    std::vector<uint8_t> vec(data, data + sizeof(data));
+
+    // Parse option.
+    Option6PDExcludePtr option;
+    ASSERT_NO_THROW(
+        option.reset(new Option6PDExclude(vec.begin() + 4, vec.end()))
+    );
+
+    // Make sure that the option has been parsed correctly.
+    EXPECT_EQ("2001:db8:dead:beef::",
+              option->getExcludedPrefix(IOAddress("2001:db8:dead::"), 48).toText());
+    EXPECT_EQ(64, static_cast<int>(option->getExcludedPrefixLength()));
+}
+
+// This test verifies that errors are reported when option buffer contains
+// invalid option data.
+TEST(Option6PDExcludeTest, unpackErrors) {
+    const uint8_t data[] = {
+        0x00, 0x43,
+        0x00, 0x02,
+        0x40, 0x78
+    };
+    std::vector<uint8_t> vec(data, data + sizeof(data));
+
+    // Option has no IPv6 subnet id.
+    EXPECT_THROW(Option6PDExclude(vec.begin() + 4, vec.end() - 1),
+                 BadValue);
+
+    // IPv6 subnet id is 0.
+    vec[4] = 0x00;
+    EXPECT_THROW(Option6PDExclude(vec.begin() + 4, vec.end()),
+                 BadValue);
+}
+
+// This test verifies conversion of the Prefix Exclude option to the
+// textual format.
+TEST(Option6PDExcludeTest, toText) {
+    Option6PDExclude option(bee0, 59, beef, 64);
+    EXPECT_EQ("type=00067, len=00002: excluded-prefix-len=64, subnet-id=0x78",
+              option.toText());
+}
+
+// This test verifies calculation of the Prefix Exclude option length.
+TEST(Option6PDExcludeTest, len) {
+   Option6PDExcludePtr option;
+   // The IPv6 subnet id is 2 bytes long. Hence the total length is
+   // 2 bytes (option code) +  2 bytes (option length) + 1 byte
+   // (excluded prefix length) + 2 bytes (IPv6 subnet id) = 7 bytes.
+   ASSERT_NO_THROW(option.reset(new Option6PDExclude(bee0, 48, beef, 64)));
+   EXPECT_EQ(7, option->len());
+
+   // IPv6 subnet id is 1 byte long. The total length is 6.
+   ASSERT_NO_THROW(option.reset(new Option6PDExclude(bee0, 59, beef, 64)));
+   EXPECT_EQ(6, option->len());
+}
+
+} // anonymous namespace