1 /*
2 * Copyright 2017 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * https://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.channel.unix;
17
18 import io.netty.buffer.ByteBuf;
19 import io.netty.util.internal.PlatformDependent;
20
21 import java.net.InetAddress;
22 import java.net.InetSocketAddress;
23 import java.net.UnknownHostException;
24
25 import static io.netty.channel.unix.Limits.IOV_MAX;
26
27 public final class UnixChannelUtil {
28
29 private UnixChannelUtil() {
30 }
31
32 /**
33 * Checks if the specified buffer has memory address or is composed of n(n <= IOV_MAX) NIO direct buffers.
34 * (We check this because otherwise we need to make it a new direct buffer.)
35 */
36 public static boolean isBufferCopyNeededForWrite(ByteBuf byteBuf) {
37 return isBufferCopyNeededForWrite(byteBuf, IOV_MAX);
38 }
39
40 static boolean isBufferCopyNeededForWrite(ByteBuf byteBuf, int iovMax) {
41 return !byteBuf.hasMemoryAddress() && (!byteBuf.isDirect() || byteBuf.nioBufferCount() > iovMax);
42 }
43
44 public static InetSocketAddress computeRemoteAddr(InetSocketAddress remoteAddr, InetSocketAddress osRemoteAddr) {
45 if (osRemoteAddr != null) {
46 if (PlatformDependent.javaVersion() >= 7) {
47 try {
48 // Only try to construct a new InetSocketAddress if we using java >= 7 as getHostString() does not
49 // exists in earlier releases and so the retrieval of the hostname could block the EventLoop if a
50 // reverse lookup would be needed.
51 return new InetSocketAddress(InetAddress.getByAddress(remoteAddr.getHostString(),
52 osRemoteAddr.getAddress().getAddress()),
53 osRemoteAddr.getPort());
54 } catch (UnknownHostException ignore) {
55 // Should never happen but fallback to osRemoteAddr anyway.
56 }
57 }
58 return osRemoteAddr;
59 }
60 return remoteAddr;
61 }
62 }