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* Licensed to the Apache Software Foundation (ASF) under one *
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* distributed with this work for additional information *
* regarding copyright ownership. The ASF 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 *
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package org.apache.james.protocols.smtp.core.fastfail;
import java.net.UnknownHostException;
import org.apache.james.protocols.smtp.DNSService;
import org.apache.james.protocols.smtp.SMTPRetCode;
import org.apache.james.protocols.smtp.SMTPSession;
import org.apache.james.protocols.smtp.dsn.DSNStatus;
import org.apache.james.protocols.smtp.hook.HeloHook;
import org.apache.james.protocols.smtp.hook.HookResult;
import org.apache.james.protocols.smtp.hook.HookReturnCode;
import org.apache.james.protocols.smtp.hook.RcptHook;
import org.apache.mailet.MailAddress;
/**
* This CommandHandler can be used to reject not resolvable EHLO/HELO
*/
public class ResolvableEhloHeloHandler implements RcptHook, HeloHook {
public final static String BAD_EHLO_HELO = "BAD_EHLO_HELO";
protected DNSService dnsService = null;
/**
* Gets the DNS service.
* @return the dnsService
*/
public final DNSService getDNSService() {
return dnsService;
}
/**
* Sets the DNS service.
* @param dnsService the dnsService to set
*/
public final void setDNSService(DNSService dnsService) {
this.dnsService = dnsService;
}
/**
* Check if EHLO/HELO is resolvable
*
* @param session
* The SMTPSession
* @param argument
* The argument
*/
protected void checkEhloHelo(SMTPSession session, String argument) {
if (isBadHelo(session, argument)) {
session.getState().put(BAD_EHLO_HELO, "true");
}
}
/**
* @param session the SMTPSession
* @param argument the argument
* @return true if the helo is bad.
*/
protected boolean isBadHelo(SMTPSession session, String argument) {
// try to resolv the provided helo. If it can not resolved do not
// accept it.
try {
dnsService.getByName(argument);
} catch (UnknownHostException e) {
return true;
}
return false;
}
/**
* @see org.apache.james.smtpserver.core.filter.fastfail.AbstractJunkHandler#check(org.apache.james.protocols.smtp.SMTPSession)
*/
protected boolean check(SMTPSession session,MailAddress rcpt) {
// not reject it
if (session.getState().get(BAD_EHLO_HELO) == null) {
return false;
}
return true;
}
/**
* @see org.apache.james.protocols.smtp.hook.RcptHook#doRcpt(org.apache.james.protocols.smtp.SMTPSession, org.apache.mailet.MailAddress, org.apache.mailet.MailAddress)
*/
public HookResult doRcpt(SMTPSession session, MailAddress sender, MailAddress rcpt) {
if (check(session,rcpt)) {
return new HookResult(HookReturnCode.DENY,SMTPRetCode.SYNTAX_ERROR_ARGUMENTS,DSNStatus.getStatus(DSNStatus.PERMANENT, DSNStatus.DELIVERY_INVALID_ARG)
+ " Provided EHLO/HELO " + session.getState().get(SMTPSession.CURRENT_HELO_NAME) + " can not resolved.");
} else {
return new HookResult(HookReturnCode.DECLINED);
}
}
/**
* @see org.apache.james.protocols.smtp.hook.HeloHook#doHelo(org.apache.james.protocols.smtp.SMTPSession, java.lang.String)
*/
public HookResult doHelo(SMTPSession session, String helo) {
checkEhloHelo(session, helo);
return new HookResult(HookReturnCode.DECLINED);
}
}