Add IPPrefix.contains()

Add helper methods to check whether the specified prefix is
entirely contained in this prefix, or the specified address
is contained in this prefix.

Bug: 184750836
Test: atest IPPrefixTest
Change-Id: I838510b347ac5741c589ee8f3983111209155588
(cherry picked from commit abe2e7fab4702113df60511f4642a6277321eb20)
Merged-In: I838510b347ac5741c589ee8f3983111209155588

2 files changed, 193 insertions, 0 deletions

diff --git a/common/netd/libnetdutils/InternetAddressesTest.cpp b/common/netd/libnetdutils/InternetAddressesTest.cpp
index f75fa76..9e37d11 100644
--- a/common/netd/libnetdutils/InternetAddressesTest.cpp
+++ b/common/netd/libnetdutils/InternetAddressesTest.cpp
@@ -21,6 +21,7 @@
 #include <vector>
 
 #include <android-base/macros.h>
+#include <fmt/format.h>
 #include <gtest/gtest.h>
 
 #include "netdutils/InternetAddresses.h"
@@ -438,6 +439,192 @@ TEST(IPPrefixTest, TruncationOther) {
     }
 }
 
+TEST(IPPrefixTest, containsPrefix) {
+    const struct {
+        const char* prefix;
+        const char* otherPrefix;
+        const bool expected;
+        std::string asParameters() const {
+            return fmt::format("prefix={}, other={}, expect={}", prefix, otherPrefix, expected);
+        }
+    } testExpectations[] = {
+            {"192.0.0.0/8", "192.0.0.0/8", true},
+            {"192.1.0.0/16", "192.1.0.0/16", true},
+            {"192.1.2.0/24", "192.1.2.0/24", true},
+            {"192.1.2.3/32", "192.1.2.3/32", true},
+            {"0.0.0.0/0", "192.0.0.0/8", true},
+            {"0.0.0.0/0", "192.1.0.0/16", true},
+            {"0.0.0.0/0", "192.1.2.0/24", true},
+            {"0.0.0.0/0", "192.1.2.3/32", true},
+            {"192.0.0.0/8", "192.1.0.0/16", true},
+            {"192.0.0.0/8", "192.1.2.0/24", true},
+            {"192.0.0.0/8", "192.1.2.5/32", true},
+            {"192.1.0.0/16", "192.1.2.0/24", true},
+            {"192.1.0.0/16", "192.1.3.6/32", true},
+            {"192.5.6.0/24", "192.5.6.7/32", true},
+            {"192.1.2.3/32", "192.1.2.0/24", false},
+            {"192.1.2.3/32", "192.1.0.0/16", false},
+            {"192.1.2.3/32", "192.0.0.0/8", false},
+            {"192.1.2.3/32", "0.0.0.0/0", false},
+            {"192.1.2.0/24", "192.1.0.0/16", false},
+            {"192.1.2.0/24", "192.0.0.0/8", false},
+            {"192.1.2.0/24", "0.0.0.0/0", false},
+            {"192.9.0.0/16", "192.0.0.0/8", false},
+            {"192.9.0.0/16", "0.0.0.0/0", false},
+            {"192.0.0.0/8", "0.0.0.0/0", false},
+            {"192.0.0.0/8", "191.0.0.0/8", false},
+            {"191.0.0.0/8", "192.0.0.0/8", false},
+            {"192.8.0.0/16", "192.7.0.0/16", false},
+            {"192.7.0.0/16", "192.8.0.0/16", false},
+            {"192.8.6.0/24", "192.7.5.0/24", false},
+            {"192.7.5.0/24", "192.8.6.0/24", false},
+            {"192.8.6.100/32", "192.8.6.200/32", false},
+            {"192.8.6.200/32", "192.8.6.100/32", false},
+            {"192.0.0.0/8", "192.0.0.0/12", true},
+            {"192.0.0.0/12", "192.0.0.0/8", false},
+            {"2001::/16", "2001::/16", true},
+            {"2001:db8::/32", "2001:db8::/32", true},
+            {"2001:db8:cafe::/48", "2001:db8:cafe::/48", true},
+            {"2001:db8:cafe:d00d::/64", "2001:db8:cafe:d00d::/64", true},
+            {"2001:db8:cafe:d00d:fec0::/80", "2001:db8:cafe:d00d:fec0::/80", true},
+            {"2001:db8:cafe:d00d:fec0:de::/96", "2001:db8:cafe:d00d:fec0:de::/96", true},
+            {"2001:db8:cafe:d00d:fec0:de:ac::/112", "2001:db8:cafe:d00d:fec0:de:ac::/112", true},
+            {"2001:db8::cafe:0:1/128", "2001:db8::cafe:0:1/128", true},
+            {"2001::/16", "2001:db8::/32", true},
+            {"2001::/16", "2001:db8:cafe::/48", true},
+            {"2001::/16", "2001:db8:cafe:d00d::/64", true},
+            {"2001::/16", "2001:db8:cafe:d00d:fec0::/80", true},
+            {"2001::/16", "2001:db8:cafe:d00d:fec0:de::/96", true},
+            {"2001::/16", "2001:db8:cafe:d00d:fec0:de:ac::/112", true},
+            {"2001::/16", "2001:db8:cafe:d00d:fec0:de:ac:dd/128", true},
+            {"::/0", "2001::/16", true},
+            {"::/0", "2001:db8::/32", true},
+            {"::/0", "2001:db8:cafe::/48", true},
+            {"::/0", "2001:db8:cafe:d00d::/64", true},
+            {"::/0", "2001:db8:cafe:d00d:fec0::/80", true},
+            {"::/0", "2001:db8:cafe:d00d:fec0:de::/96", true},
+            {"::/0", "2001:db8:cafe:d00d:fec0:de:ac::/112", true},
+            {"::/0", "2001:db8:cafe:d00d:fec0:de:ac:dd/128", true},
+            {"2001:db8::dd/128", "2001::/16", false},
+            {"2001:db8::dd/128", "2001:db8::/32", false},
+            {"2001:db8::dd/128", "2001:db8:cafe::/48", false},
+            {"2001:db8::dd/128", "2001:db8:cafe:d00d::/64", false},
+            {"2001:db8::dd/128", "2001:db8:cafe:d00d:fec0::/80", false},
+            {"2001:db8::dd/128", "2001:db8:cafe:d00d:fec0:de::/96", false},
+            {"2001:db8::dd/128", "2001:db8:cafe:d00d:fec0:de:ac::/112", false},
+            {"2001:db7::/32", "2001:db8::/32", false},
+            {"2001:db8::/32", "2001:db7::/32", false},
+            {"2001:db8:caff::/48", "2001:db8:cafe::/48", false},
+            {"2001:db8:cafe::/48", "2001:db8:caff::/48", false},
+            {"2001:db8:cafe:a00d::/64", "2001:db8:cafe:d00d::/64", false},
+            {"2001:db8:cafe:d00d::/64", "2001:db8:cafe:a00d::/64", false},
+            {"2001:db8:cafe:d00d:fec1::/80", "2001:db8:cafe:d00d:fec0::/80", false},
+            {"2001:db8:cafe:d00d:fec0::/80", "2001:db8:cafe:d00d:fec1::/80", false},
+            {"2001:db8:cafe:d00d:fec0:dd::/96", "2001:db8:cafe:d00d:fec0:ae::/96", false},
+            {"2001:db8:cafe:d00d:fec0:ae::/96", "2001:db8:cafe:d00d:fec0:dd::/96", false},
+            {"2001:db8:cafe:d00d:fec0:de:aa::/112", "2001:db8:cafe:d00d:fec0:de:ac::/112", false},
+            {"2001:db8:cafe:d00d:fec0:de:ac::/112", "2001:db8:cafe:d00d:fec0:de:aa::/112", false},
+            {"2001:db8::cafe:0:123/128", "2001:db8::cafe:0:456/128", false},
+            {"2001:db8::cafe:0:456/128", "2001:db8::cafe:0:123/128", false},
+            {"2001:db8::/32", "2001:db8::/64", true},
+            {"2001:db8::/64", "2001:db8::/32", false},
+            {"::/0", "0.0.0.0/0", false},
+            {"::/0", "1.0.0.0/8", false},
+            {"::/0", "1.2.0.0/16", false},
+            {"::/0", "1.2.3.0/24", false},
+            {"::/0", "1.2.3.4/32", false},
+            {"2001::/16", "1.2.3.4/32", false},
+            {"2001::db8::/32", "1.2.3.4/32", false},
+            {"2001:db8:cafe::/48", "1.2.3.4/32", false},
+            {"2001:db8:cafe:d00d::/64", "1.2.3.4/32", false},
+            {"2001:db8:cafe:d00d:fec0::/80", "1.2.3.4/32", false},
+            {"2001:db8:cafe:d00d:fec0:ae::/96", "1.2.3.4/32", false},
+            {"2001:db8:cafe:d00d:fec0:de:aa::/112", "1.2.3.4/32", false},
+            {"0.0.0.0/0", "::/0", false},
+            {"0.0.0.0/0", "2001::/16", false},
+            {"0.0.0.0/0", "2001::db8::/32", false},
+            {"0.0.0.0/0", "2001:db8:cafe::/48", false},
+            {"0.0.0.0/0", "2001:db8:cafe:d00d::/64", false},
+            {"0.0.0.0/0", "2001:db8:cafe:d00d:fec0::/80", false},
+            {"0.0.0.0/0", "2001:db8:cafe:d00d:fec0:ae::/96", false},
+            {"0.0.0.0/0", "2001:db8:cafe:d00d:fec0:de:aa::/112", false},
+            {"1.2.3.4/32", "2001:db8:cafe:d00d:fec0:de:aa::/112", false},
+            {"1.2.3.0/24", "2001:db8:cafe:d00d:fec0:de:aa::/112", false},
+            {"1.2.0.0/16", "2001:db8:cafe:d00d:fec0:de:aa::/112", false},
+            {"1.0.0.0/8", "2001:db8:cafe:d00d:fec0:de:aa::/112", false},
+    };
+
+    for (const auto& expectation : testExpectations) {
+        SCOPED_TRACE(expectation.asParameters());
+        IPPrefix a = IPPrefix::forString(expectation.prefix);
+        IPPrefix b = IPPrefix::forString(expectation.otherPrefix);
+        EXPECT_EQ(expectation.expected, a.contains(b));
+    }
+}
+
+TEST(IPPrefixTest, containsAddress) {
+    const struct {
+        const char* prefix;
+        const char* address;
+        const bool expected;
+        std::string asParameters() const {
+            return fmt::format("prefix={}, address={}, expect={}", prefix, address, expected);
+        }
+    } testExpectations[] = {
+        {"0.0.0.0/0", "255.255.255.255", true},
+        {"0.0.0.0/0", "1.2.3.4", true},
+        {"0.0.0.0/0", "1.2.3.0", true},
+        {"0.0.0.0/0", "1.2.0.0", true},
+        {"0.0.0.0/0", "1.0.0.0", true},
+        {"0.0.0.0/0", "0.0.0.0", true},
+        {"0.0.0.0/0", "2001:4868:4860::8888", false},
+        {"0.0.0.0/0", "::/0", false},
+        {"192.0.2.0/23", "192.0.2.0", true},
+        {"192.0.2.0/23", "192.0.2.43", true},
+        {"192.0.2.0/23", "192.0.3.21", true},
+        {"192.0.2.0/23", "192.0.0.21", false},
+        {"192.0.2.0/23", "8.8.8.8", false},
+        {"192.0.2.0/23", "2001:4868:4860::8888", false},
+        {"192.0.2.0/23", "::/0", false},
+        {"1.2.3.4/32", "1.2.3.4", true},
+        {"1.2.3.4/32", "1.2.3.5", false},
+        {"10.0.0.0/8", "10.2.0.0", true},
+        {"10.0.0.0/8", "10.2.3.5", true},
+        {"10.0.0.0/8", "10.0.0.0", true},
+        {"10.0.0.0/8", "10.255.255.254", true},
+        {"10.0.0.0/8", "11.0.0.0", false},
+        {"::/0", "2001:db8:f000::ace:d00c", true},
+        {"::/0", "2002:db8:f00::ace:d00d", true},
+        {"::/0", "2001:db7:f00::ace:d00e", true},
+        {"::/0", "2001:db8:f01::bad:d00d", true},
+        {"::/0", "::", true},
+        {"::/0", "0.0.0.0", false},
+        {"::/0", "1.2.3.4", false},
+        {"2001:db8:f00::ace:d00d/127", "2001:db8:f00::ace:d00c", true},
+        {"2001:db8:f00::ace:d00d/127", "2001:db8:f00::ace:d00d", true},
+        {"2001:db8:f00::ace:d00d/127", "2001:db8:f00::ace:d00e", false},
+        {"2001:db8:f00::ace:d00d/127", "2001:db8:f00::bad:d00d", false},
+        {"2001:db8:f00::ace:d00d/127", "2001:4868:4860::8888", false},
+        {"2001:db8:f00::ace:d00d/127", "8.8.8.8", false},
+        {"2001:db8:f00::ace:d00d/127", "0.0.0.0", false},
+        {"2001:db8:f00::ace:d00d/128", "2001:db8:f00::ace:d00d", true},
+        {"2001:db8:f00::ace:d00d/128", "2001:db8:f00::ace:d00c", false},
+        {"2001::/16", "2001::", true},
+        {"2001::/16", "2001:db8:f00::ace:d00d", true},
+        {"2001::/16", "2001:db8:f00::bad:d00d", true},
+        {"2001::/16", "2001::abc", true},
+        {"2001::/16", "2001:ffff:ffff:ffff:ffff:ffff:ffff:ffff", true},
+        {"2001::/16", "2000::", false},
+    };
+
+    for (const auto& expectation : testExpectations) {
+        SCOPED_TRACE(expectation.asParameters());
+        IPPrefix a = IPPrefix::forString(expectation.prefix);
+        IPAddress b = IPAddress::forString(expectation.address);
+        EXPECT_EQ(expectation.expected, a.contains(b));
+    }
+}
+
 TEST(IPPrefixTest, GamutOfOperators) {
     const std::vector<OperatorExpectation<IPPrefix>> kExpectations{
             {EQ, IPPrefix(), IPPrefix()},
diff --git a/common/netd/libnetdutils/include/netdutils/InternetAddresses.h b/common/netd/libnetdutils/include/netdutils/InternetAddresses.h
index d5cbe2b..d10cec7 100644
--- a/common/netd/libnetdutils/include/netdutils/InternetAddresses.h
+++ b/common/netd/libnetdutils/include/netdutils/InternetAddresses.h
@@ -221,6 +221,12 @@ class IPPrefix {
     in_addr addr4() const noexcept { return mData.ip.v4; }
     in6_addr addr6() const noexcept { return mData.ip.v6; }
     constexpr int length() const noexcept { return mData.cidrlen; }
+    bool contains(const IPPrefix& other) {
+        return length() <= other.length() && IPPrefix(other.ip(), length()).ip() == ip();
+    }
+    bool contains(const IPAddress& other) {
+        return IPPrefix(other, length()).ip() == ip();
+    }
 
     bool isUninitialized() const noexcept;
     std::string toString() const noexcept;