AK: Add IPv6Address class

This is the IPv6 counter part to the IPv4Address class and implements
parsing strings into a in6_addr and formatting one as a string. It
supports the address compression scheme as well as IPv4 mapped
addresses.

2 files changed, 119 insertions, 0 deletions

diff --git a/Tests/AK/CMakeLists.txt b/Tests/AK/CMakeLists.txt
index eed34f479a..7a62045a7e 100644
--- a/Tests/AK/CMakeLists.txt
+++ b/Tests/AK/CMakeLists.txt
@@ -32,6 +32,7 @@ set(AK_TEST_SOURCES
     TestHashTable.cpp
     TestHex.cpp
     TestIPv4Address.cpp
+    TestIPv6Address.cpp
     TestIndexSequence.cpp
     TestIntegerMath.cpp
     TestIntrusiveList.cpp
diff --git a/Tests/AK/TestIPv6Address.cpp b/Tests/AK/TestIPv6Address.cpp
new file mode 100644
index 0000000000..a8cfb1f33b
--- /dev/null
+++ b/Tests/AK/TestIPv6Address.cpp
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2022, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibTest/TestCase.h>
+
+#include <AK/Endian.h>
+#include <AK/IPv6Address.h>
+
+TEST_CASE(should_default_contructor_with_0s)
+{
+    constexpr IPv6Address addr {};
+
+    static_assert(addr.is_zero());
+
+    EXPECT(addr.is_zero());
+}
+
+TEST_CASE(should_construct_from_c_array)
+{
+    constexpr auto addr = [] {
+        u8 const a[16] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
+        return IPv6Address(a);
+    }();
+
+    static_assert(!addr.is_zero());
+
+    EXPECT(!addr.is_zero());
+}
+
+TEST_CASE(should_get_groups_by_index)
+{
+    constexpr IPv6Address addr({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 });
+
+    static_assert(0x102 == addr[0]);
+    static_assert(0x304 == addr[1]);
+    static_assert(0x506 == addr[2]);
+    static_assert(0x708 == addr[3]);
+    static_assert(0x90a == addr[4]);
+    static_assert(0xb0c == addr[5]);
+    static_assert(0xd0e == addr[6]);
+    static_assert(0xf10 == addr[7]);
+
+    EXPECT_EQ(0x102, addr[0]);
+    EXPECT_EQ(0x304, addr[1]);
+    EXPECT_EQ(0x506, addr[2]);
+    EXPECT_EQ(0x708, addr[3]);
+    EXPECT_EQ(0x90a, addr[4]);
+    EXPECT_EQ(0xb0c, addr[5]);
+    EXPECT_EQ(0xd0e, addr[6]);
+    EXPECT_EQ(0xf10, addr[7]);
+}
+
+TEST_CASE(should_convert_to_string)
+{
+    EXPECT_EQ("102:304:506:708:90a:b0c:d0e:f10"sv, IPv6Address({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }).to_string());
+    EXPECT_EQ("::"sv, IPv6Address().to_string());
+    EXPECT_EQ("::1"sv, IPv6Address({ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }).to_string());
+    EXPECT_EQ("1::"sv, IPv6Address({ 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }).to_string());
+    EXPECT_EQ("102:0:506:708:900::10"sv, IPv6Address({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 16 }).to_string());
+    EXPECT_EQ("102:0:506:708:900::"sv, IPv6Address({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 0 }).to_string());
+    EXPECT_EQ("::304:506:708:90a:b0c:d0e:f10"sv, IPv6Address({ 0, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }).to_string());
+    EXPECT_EQ("102:304::708:90a:b0c:d0e:f10"sv, IPv6Address({ 1, 2, 3, 4, 0, 0, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }).to_string());
+}
+
+TEST_CASE(should_make_ipv6_address_from_string)
+{
+    EXPECT(!IPv6Address::from_string(":::"sv).has_value());
+    EXPECT(!IPv6Address::from_string(":::1"sv).has_value());
+    EXPECT(!IPv6Address::from_string("1:::"sv).has_value());
+    EXPECT_EQ(IPv6Address::from_string("102:304:506:708:90a:b0c:d0e:f10"sv).value(), IPv6Address({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
+    EXPECT_EQ(IPv6Address::from_string("::"sv).value(), IPv6Address());
+    EXPECT_EQ(IPv6Address::from_string("::1"sv).value(), IPv6Address({ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }));
+    EXPECT_EQ(IPv6Address::from_string("1::"sv).value(), IPv6Address({ 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }));
+    EXPECT_EQ(IPv6Address::from_string("102:0:506:708:900::10"sv).value(), IPv6Address({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 16 }));
+    EXPECT_EQ(IPv6Address::from_string("102:0:506:708:900::"sv).value(), IPv6Address({ 1, 2, 0, 0, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 0 }));
+    EXPECT_EQ(IPv6Address::from_string("::304:506:708:90a:b0c:d0e:f10"sv).value(), IPv6Address({ 0, 0, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
+    EXPECT_EQ(IPv6Address::from_string("102:304::708:90a:b0c:d0e:f10"sv).value(), IPv6Address({ 1, 2, 3, 4, 0, 0, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }));
+}
+
+TEST_CASE(ipv4_mapped_ipv6)
+{
+    auto ipv4_address_to_map = IPv4Address::from_string("192.168.0.1"sv).release_value();
+    IPv6Address mapped_address(ipv4_address_to_map);
+    EXPECT(mapped_address.is_ipv4_mapped());
+    EXPECT_EQ(ipv4_address_to_map, mapped_address.ipv4_mapped_address().value());
+    EXPECT_EQ("::ffff:192.168.0.1"sv, mapped_address.to_string());
+    EXPECT_EQ(IPv4Address(192, 168, 1, 9), IPv6Address::from_string("::FFFF:192.168.1.9"sv).value().ipv4_mapped_address().value());
+    EXPECT(!IPv6Address::from_string("::abcd:192.168.1.9"sv).has_value());
+}
+
+TEST_CASE(should_make_empty_optional_from_bad_string)
+{
+    auto const addr = IPv6Address::from_string("bad string"sv);
+
+    EXPECT(!addr.has_value());
+}
+
+TEST_CASE(should_make_empty_optional_from_out_of_range_values)
+{
+    auto const addr = IPv6Address::from_string("::10000"sv);
+
+    EXPECT(!addr.has_value());
+}
+
+TEST_CASE(should_compare)
+{
+    constexpr IPv6Address addr_a({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 });
+    constexpr IPv6Address addr_b({ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17 });
+
+    static_assert(addr_a != addr_b);
+    static_assert(addr_a == addr_a);
+
+    EXPECT(addr_a != addr_b);
+    EXPECT(addr_a == addr_a);
+}