/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.handler.codec.socks;
import io.netty.buffer.ByteBuf;
import io.netty.util.CharsetUtil;
import io.netty.util.NetUtil;
import java.net.IDN;
/**
* A socks cmd response.
*
* @see SocksCmdRequest
* @see SocksCmdResponseDecoder
*/
public final class SocksCmdResponse extends SocksResponse {
private final SocksCmdStatus cmdStatus;
private final SocksAddressType addressType;
private final String host;
private final int port;
// All arrays are initialized on construction time to 0/false/null remove array Initialization
private static final byte[] DOMAIN_ZEROED = {0x00};
private static final byte[] IPv4_HOSTNAME_ZEROED = {0x00, 0x00, 0x00, 0x00};
private static final byte[] IPv6_HOSTNAME_ZEROED = {0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00};
public SocksCmdResponse(SocksCmdStatus cmdStatus, SocksAddressType addressType) {
this(cmdStatus, addressType, null, 0);
}
/**
* Constructs new response and includes provided host and port as part of it.
*
* @param cmdStatus status of the response
* @param addressType type of host parameter
* @param host host (BND.ADDR field) is address that server used when connecting to the target host.
* When null a value of 4/8 0x00 octets will be used for IPv4/IPv6 and a single 0x00 byte will be
* used for domain addressType. Value is converted to ASCII using {@link IDN#toASCII(String)}.
* @param port port (BND.PORT field) that the server assigned to connect to the target host
* @throws NullPointerException in case cmdStatus or addressType are missing
* @throws IllegalArgumentException in case host or port cannot be validated
* @see IDN#toASCII(String)
*/
public SocksCmdResponse(SocksCmdStatus cmdStatus, SocksAddressType addressType, String host, int port) {
super(SocksResponseType.CMD);
if (cmdStatus == null) {
throw new NullPointerException("cmdStatus");
}
if (addressType == null) {
throw new NullPointerException("addressType");
}
if (host != null) {
switch (addressType) {
case IPv4:
if (!NetUtil.isValidIpV4Address(host)) {
throw new IllegalArgumentException(host + " is not a valid IPv4 address");
}
break;
case DOMAIN:
if (IDN.toASCII(host).length() > 255) {
throw new IllegalArgumentException(host + " IDN: " +
IDN.toASCII(host) + " exceeds 255 char limit");
}
break;
case IPv6:
if (!NetUtil.isValidIpV6Address(host)) {
throw new IllegalArgumentException(host + " is not a valid IPv6 address");
}
break;
case UNKNOWN:
break;
}
host = IDN.toASCII(host);
}
if (port < 0 || port > 65535) {
throw new IllegalArgumentException(port + " is not in bounds 0 <= x <= 65535");
}
this.cmdStatus = cmdStatus;
this.addressType = addressType;
this.host = host;
this.port = port;
}
/**
* Returns the {@link SocksCmdStatus} of this {@link SocksCmdResponse}
*
* @return The {@link SocksCmdStatus} of this {@link SocksCmdResponse}
*/
public SocksCmdStatus cmdStatus() {
return cmdStatus;
}
/**
* Returns the {@link SocksAddressType} of this {@link SocksCmdResponse}
*
* @return The {@link SocksAddressType} of this {@link SocksCmdResponse}
*/
public SocksAddressType addressType() {
return addressType;
}
/**
* Returns host that is used as a parameter in {@link io.netty.handler.codec.socks.SocksCmdType}.
* Host (BND.ADDR field in response) is address that server used when connecting to the target host.
* This is typically different from address which client uses to connect to the SOCKS server.
*
* @return host that is used as a parameter in {@link io.netty.handler.codec.socks.SocksCmdType}
* or null when there was no host specified during response construction
*/
public String host() {
if (host != null) {
return IDN.toUnicode(host);
} else {
return null;
}
}
/**
* Returns port that is used as a parameter in {@link io.netty.handler.codec.socks.SocksCmdType}.
* Port (BND.PORT field in response) is port that the server assigned to connect to the target host.
*
* @return port that is used as a parameter in {@link io.netty.handler.codec.socks.SocksCmdType}
*/
public int port() {
return port;
}
@Override
public void encodeAsByteBuf(ByteBuf byteBuf) {
byteBuf.writeByte(protocolVersion().byteValue());
byteBuf.writeByte(cmdStatus.byteValue());
byteBuf.writeByte(0x00);
byteBuf.writeByte(addressType.byteValue());
switch (addressType) {
case IPv4: {
byte[] hostContent = host == null ?
IPv4_HOSTNAME_ZEROED : NetUtil.createByteArrayFromIpAddressString(host);
byteBuf.writeBytes(hostContent);
byteBuf.writeShort(port);
break;
}
case DOMAIN: {
byte[] hostContent = host == null ?
DOMAIN_ZEROED : host.getBytes(CharsetUtil.US_ASCII);
byteBuf.writeByte(hostContent.length); // domain length
byteBuf.writeBytes(hostContent); // domain value
byteBuf.writeShort(port); // port value
break;
}
case IPv6: {
byte[] hostContent = host == null
? IPv6_HOSTNAME_ZEROED : NetUtil.createByteArrayFromIpAddressString(host);
byteBuf.writeBytes(hostContent);
byteBuf.writeShort(port);
break;
}
}
}
}