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1   /*
2    * Copyright 2014 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    *   http://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.epoll;
17  
18  import io.netty.channel.Channel;
19  import io.netty.channel.ChannelException;
20  import io.netty.channel.socket.ServerSocketChannel;
21  import io.netty.channel.socket.SocketChannel;
22  import io.netty.util.concurrent.GlobalEventExecutor;
23  
24  import java.io.IOException;
25  import java.net.InetAddress;
26  import java.net.InetSocketAddress;
27  import java.util.Collection;
28  import java.util.Collections;
29  import java.util.Map;
30  import java.util.concurrent.Executor;
31  
32  import static io.netty.channel.epoll.LinuxSocket.newSocketStream;
33  
34  /**
35   * {@link SocketChannel} implementation that uses linux EPOLL Edge-Triggered Mode for
36   * maximal performance.
37   */
38  public final class EpollSocketChannel extends AbstractEpollStreamChannel implements SocketChannel {
39  
40      private final EpollSocketChannelConfig config;
41  
42      private volatile Collection<InetAddress> tcpMd5SigAddresses = Collections.emptyList();
43  
44      public EpollSocketChannel() {
45          super(newSocketStream(), false);
46          config = new EpollSocketChannelConfig(this);
47      }
48  
49      public EpollSocketChannel(int fd) {
50          super(fd);
51          config = new EpollSocketChannelConfig(this);
52      }
53  
54      EpollSocketChannel(LinuxSocket fd, boolean active) {
55          super(fd, active);
56          config = new EpollSocketChannelConfig(this);
57      }
58  
59      EpollSocketChannel(Channel parent, LinuxSocket fd, InetSocketAddress remoteAddress) {
60          super(parent, fd, remoteAddress);
61          config = new EpollSocketChannelConfig(this);
62  
63          if (parent instanceof EpollServerSocketChannel) {
64              tcpMd5SigAddresses = ((EpollServerSocketChannel) parent).tcpMd5SigAddresses();
65          }
66      }
67  
68      /**
69       * Returns the {@code TCP_INFO} for the current socket. See <a href="http://linux.die.net/man/7/tcp">man 7 tcp</a>.
70       */
71      public EpollTcpInfo tcpInfo() {
72          return tcpInfo(new EpollTcpInfo());
73      }
74  
75      /**
76       * Updates and returns the {@code TCP_INFO} for the current socket.
77       * See <a href="http://linux.die.net/man/7/tcp">man 7 tcp</a>.
78       */
79      public EpollTcpInfo tcpInfo(EpollTcpInfo info) {
80          try {
81              socket.getTcpInfo(info);
82              return info;
83          } catch (IOException e) {
84              throw new ChannelException(e);
85          }
86      }
87  
88      @Override
89      public InetSocketAddress remoteAddress() {
90          return (InetSocketAddress) super.remoteAddress();
91      }
92  
93      @Override
94      public InetSocketAddress localAddress() {
95          return (InetSocketAddress) super.localAddress();
96      }
97  
98      @Override
99      public EpollSocketChannelConfig config() {
100         return config;
101     }
102 
103     @Override
104     public ServerSocketChannel parent() {
105         return (ServerSocketChannel) super.parent();
106     }
107 
108     @Override
109     protected AbstractEpollUnsafe newUnsafe() {
110         return new EpollSocketChannelUnsafe();
111     }
112 
113     private final class EpollSocketChannelUnsafe extends EpollStreamUnsafe {
114         @Override
115         protected Executor prepareToClose() {
116             try {
117                 // Check isOpen() first as otherwise it will throw a RuntimeException
118                 // when call getSoLinger() as the fd is not valid anymore.
119                 if (isOpen() && config().getSoLinger() > 0) {
120                     // We need to cancel this key of the channel so we may not end up in a eventloop spin
121                     // because we try to read or write until the actual close happens which may be later due
122                     // SO_LINGER handling.
123                     // See https://github.com/netty/netty/issues/4449
124                     ((EpollEventLoop) eventLoop()).remove(EpollSocketChannel.this);
125                     return GlobalEventExecutor.INSTANCE;
126                 }
127             } catch (Throwable ignore) {
128                 // Ignore the error as the underlying channel may be closed in the meantime and so
129                 // getSoLinger() may produce an exception. In this case we just return null.
130                 // See https://github.com/netty/netty/issues/4449
131             }
132             return null;
133         }
134     }
135 
136     void setTcpMd5Sig(Map<InetAddress, byte[]> keys) throws IOException {
137         tcpMd5SigAddresses = TcpMd5Util.newTcpMd5Sigs(this, tcpMd5SigAddresses, keys);
138     }
139 }