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
20 import java.io.IOException;
21 import java.net.InetAddress;
22 import java.net.InetSocketAddress;
23 import java.net.UnknownHostException;
24 import java.nio.file.Files;
25 import java.nio.file.InvalidPathException;
26 import java.nio.file.LinkOption;
27 import java.nio.file.Path;
28 import java.nio.file.Paths;
29 import java.nio.file.attribute.BasicFileAttributes;
30
31 import static io.netty.channel.unix.Limits.IOV_MAX;
32
33 public final class UnixChannelUtil {
34
35 private UnixChannelUtil() {
36 }
37
38 /**
39 * Checks if the specified buffer has memory address or is composed of n(n <= IOV_MAX) NIO direct buffers.
40 * (We check this because otherwise we need to make it a new direct buffer.)
41 */
42 public static boolean isBufferCopyNeededForWrite(ByteBuf byteBuf) {
43 return isBufferCopyNeededForWrite(byteBuf, IOV_MAX);
44 }
45
46 static boolean isBufferCopyNeededForWrite(ByteBuf byteBuf, int iovMax) {
47 return !byteBuf.hasMemoryAddress() && (!byteBuf.isDirect() || byteBuf.nioBufferCount() > iovMax);
48 }
49
50 /**
51 * Delete the file at {@code path} but only if it is not a regular file, directory or symbolic link (i.e. it is
52 * a socket inode as left behind by a bound domain socket). Symbolic links are never followed.
53 *
54 * @return {@code true} if the file was deleted.
55 */
56 public static boolean deleteDomainSocketFile(String path) {
57 try {
58 Path file = Paths.get(path);
59 BasicFileAttributes attrs = Files.readAttributes(file, BasicFileAttributes.class,
60 LinkOption.NOFOLLOW_LINKS);
61 if (!attrs.isOther()) {
62 return false;
63 }
64 Files.delete(file);
65 return true;
66 } catch (IOException ignore) {
67 return false;
68 } catch (InvalidPathException ignore) {
69 // For example abstract namespace addresses, which have no file system presence.
70 return false;
71 }
72 }
73
74 public static InetSocketAddress computeRemoteAddr(InetSocketAddress remoteAddr, InetSocketAddress osRemoteAddr) {
75 if (osRemoteAddr != null) {
76 try {
77 // Only try to construct a new InetSocketAddress if we using java >= 7 as getHostString() does not
78 // exists in earlier releases and so the retrieval of the hostname could block the EventLoop if a
79 // reverse lookup would be needed.
80 return new InetSocketAddress(InetAddress.getByAddress(remoteAddr.getHostString(),
81 osRemoteAddr.getAddress().getAddress()),
82 osRemoteAddr.getPort());
83 } catch (UnknownHostException ignore) {
84 // Should never happen but fallback to osRemoteAddr anyway.
85 }
86 return osRemoteAddr;
87 }
88 return remoteAddr;
89 }
90 }