diff options
Diffstat (limited to 'common/framework/com/android/net/module/util/IpRange.java')
| -rw-r--r-- | common/framework/com/android/net/module/util/IpRange.java | 223 |
1 files changed, 0 insertions, 223 deletions
diff --git a/common/framework/com/android/net/module/util/IpRange.java b/common/framework/com/android/net/module/util/IpRange.java deleted file mode 100644 index 0a3f95be..00000000 --- a/common/framework/com/android/net/module/util/IpRange.java +++ /dev/null @@ -1,223 +0,0 @@ -/* - * Copyright (C) 2020 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -package com.android.net.module.util; - -import static com.android.internal.annotations.VisibleForTesting.Visibility; - -import android.annotation.NonNull; -import android.net.IpPrefix; - -import com.android.internal.annotations.VisibleForTesting; - -import java.math.BigInteger; -import java.net.InetAddress; -import java.net.UnknownHostException; -import java.util.ArrayList; -import java.util.Arrays; -import java.util.LinkedList; -import java.util.List; -import java.util.Objects; -import java.util.Queue; - -/** - * This class represents an IP range, i.e., a contiguous block of IP addresses defined by a starting - * and ending IP address. These addresses may not be power-of-two aligned. - * - * <p>Conversion to prefixes are deterministic, and will always return the same set of {@link - * IpPrefix}(es). Ordering of IpPrefix instances is not guaranteed. - * - * @hide - */ -public final class IpRange { - private static final int SIGNUM_POSITIVE = 1; - - private final byte[] mStartAddr; - private final byte[] mEndAddr; - - public IpRange(@NonNull InetAddress startAddr, @NonNull InetAddress endAddr) { - Objects.requireNonNull(startAddr, "startAddr must not be null"); - Objects.requireNonNull(endAddr, "endAddr must not be null"); - - if (!startAddr.getClass().equals(endAddr.getClass())) { - throw new IllegalArgumentException("Invalid range: Address family mismatch"); - } - if (addrToBigInteger(startAddr.getAddress()).compareTo( - addrToBigInteger(endAddr.getAddress())) >= 0) { - throw new IllegalArgumentException( - "Invalid range; start address must be before end address"); - } - - mStartAddr = startAddr.getAddress(); - mEndAddr = endAddr.getAddress(); - } - - @VisibleForTesting(visibility = Visibility.PRIVATE) - public IpRange(@NonNull IpPrefix prefix) { - Objects.requireNonNull(prefix, "prefix must not be null"); - - // Use masked address from IpPrefix to zero out lower order bits. - mStartAddr = prefix.getRawAddress(); - - // Set all non-prefix bits to max. - mEndAddr = prefix.getRawAddress(); - for (int bitIndex = prefix.getPrefixLength(); bitIndex < 8 * mEndAddr.length; ++bitIndex) { - mEndAddr[bitIndex / 8] |= (byte) (0x80 >> (bitIndex % 8)); - } - } - - private static InetAddress getAsInetAddress(byte[] address) { - try { - return InetAddress.getByAddress(address); - } catch (UnknownHostException e) { - // Cannot happen. InetAddress.getByAddress can only throw an exception if the byte - // array is the wrong length, but are always generated from InetAddress(es). - throw new IllegalArgumentException("Address is invalid"); - } - } - - @VisibleForTesting(visibility = Visibility.PRIVATE) - public InetAddress getStartAddr() { - return getAsInetAddress(mStartAddr); - } - - @VisibleForTesting(visibility = Visibility.PRIVATE) - public InetAddress getEndAddr() { - return getAsInetAddress(mEndAddr); - } - - /** - * Converts this IP range to a list of IpPrefix instances. - * - * <p>This method outputs the IpPrefix instances for use in the routing architecture. - * - * <p>For example, the range 192.0.2.4 - 192.0.3.1 converts to the following prefixes: - * - * <ul> - * <li>192.0.2.128/25 - * <li>192.0.2.64/26 - * <li>192.0.2.32/27 - * <li>192.0.2.16/28 - * <li>192.0.2.8/29 - * <li>192.0.2.4/30 - * <li>192.0.3.0/31 - * </ul> - */ - public List<IpPrefix> asIpPrefixes() { - final boolean isIpv6 = (mStartAddr.length == 16); - final List<IpPrefix> result = new ArrayList<>(); - final Queue<IpPrefix> workingSet = new LinkedList<>(); - - // Start with the any-address. Inet4/6Address.ANY requires compiling against - // core-platform-api. - workingSet.add(new IpPrefix(isIpv6 ? getAsInetAddress(new byte[16]) /* IPv6_ANY */ - : getAsInetAddress(new byte[4]) /* IPv4_ANY */, 0)); - - // While items are still in the queue, test and narrow to subsets. - while (!workingSet.isEmpty()) { - final IpPrefix workingPrefix = workingSet.poll(); - final IpRange workingRange = new IpRange(workingPrefix); - - // If the other range is contained within, it's part of the output. Do not test subsets, - // or we will end up with duplicates. - if (containsRange(workingRange)) { - result.add(workingPrefix); - continue; - } - - // If there is any overlap, split the working range into it's two subsets, and - // reevaluate those. - if (overlapsRange(workingRange)) { - workingSet.addAll(getSubsetPrefixes(workingPrefix)); - } - } - - return result; - } - - /** - * Returns the two prefixes that comprise the given prefix. - * - * <p>For example, for the prefix 192.0.2.0/24, this will return the two prefixes that combined - * make up the current prefix: - * - * <ul> - * <li>192.0.2.0/25 - * <li>192.0.2.128/25 - * </ul> - */ - private static List<IpPrefix> getSubsetPrefixes(IpPrefix prefix) { - final List<IpPrefix> result = new ArrayList<>(); - - final int currentPrefixLen = prefix.getPrefixLength(); - result.add(new IpPrefix(prefix.getAddress(), currentPrefixLen + 1)); - - final byte[] other = prefix.getRawAddress(); - other[currentPrefixLen / 8] = - (byte) (other[currentPrefixLen / 8] ^ (0x80 >> (currentPrefixLen % 8))); - result.add(new IpPrefix(getAsInetAddress(other), currentPrefixLen + 1)); - - return result; - } - - /** - * Checks if the other IP range is contained within this one - * - * <p>Checks based on byte values. For other to be contained within this IP range, other's - * starting address must be greater or equal to the current IpRange's starting address, and the - * other's ending address must be less than or equal to the current IP range's ending address. - */ - @VisibleForTesting(visibility = Visibility.PRIVATE) - public boolean containsRange(IpRange other) { - return addrToBigInteger(mStartAddr).compareTo(addrToBigInteger(other.mStartAddr)) <= 0 - && addrToBigInteger(mEndAddr).compareTo(addrToBigInteger(other.mEndAddr)) >= 0; - } - - /** - * Checks if the other IP range overlaps with this one - * - * <p>Checks based on byte values. For there to be overlap, this IpRange's starting address must - * be less than the other's ending address, and vice versa. - */ - @VisibleForTesting(visibility = Visibility.PRIVATE) - public boolean overlapsRange(IpRange other) { - return addrToBigInteger(mStartAddr).compareTo(addrToBigInteger(other.mEndAddr)) <= 0 - && addrToBigInteger(other.mStartAddr).compareTo(addrToBigInteger(mEndAddr)) <= 0; - } - - @Override - public int hashCode() { - return Objects.hash(Arrays.hashCode(mStartAddr), Arrays.hashCode(mEndAddr)); - } - - @Override - public boolean equals(Object obj) { - if (!(obj instanceof IpRange)) { - return false; - } - - final IpRange other = (IpRange) obj; - return Arrays.equals(mStartAddr, other.mStartAddr) - && Arrays.equals(mEndAddr, other.mEndAddr); - } - - /** Gets the InetAddress in BigInteger form */ - private static BigInteger addrToBigInteger(byte[] addr) { - // Since addr.getAddress() returns network byte order (big-endian), it is compatible with - // the BigInteger constructor (which assumes big-endian). - return new BigInteger(SIGNUM_POSITIVE, addr); - } -} |