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1
21 package org.jsmtpd.plugins.smtpExtension;
22
23 import java.io.IOException  ;
24 import java.net.InetAddress ;
25 import java.net.InetSocketAddress ;
26 import java.net.Socket ;
27 import java.net.SocketAddress ;
28 import java.util.List ;
29
30 import org.apache.commons.logging.Log;
31 import org.apache.commons.logging.LogFactory;
32 import org.jsmtpd.core.common.PluginInitException;
33 import org.jsmtpd.core.common.PluginStore;
34 import org.jsmtpd.core.common.acl.IACL;
35 import org.jsmtpd.core.common.dnsService.IDNSResolver;
36 import org.jsmtpd.core.common.io.BareLFException;
37 import org.jsmtpd.core.common.io.InputSizeToBig;
38 import org.jsmtpd.core.common.smtpExtension.IProtocolHandler;
39 import org.jsmtpd.core.common.smtpExtension.ISmtpExtension;
40 import org.jsmtpd.core.common.smtpExtension.SmtpExtensionException;
41
42
52 public class ConnectBackCheck implements ISmtpExtension {
53 private IACL acl;
54 private Log log = LogFactory.getLog(ConnectBackCheck.class);
55 private IDNSResolver resolver;
56 public boolean smtpTrigger(String command, IProtocolHandler protocol) throws SmtpExtensionException, IOException , InputSizeToBig, IOException , BareLFException {
57 return true;
58 }
59
60 public boolean smtpPreTrigger(String command, IProtocolHandler protocol) throws SmtpExtensionException, IOException , InputSizeToBig, IOException , BareLFException {
61
62 if (command==null) {
63 log.error("Null command, skipping...");
64 return false;
65 }
66
67 if (command.toLowerCase().equals("data")) {
68 log.debug("Data command issued, checking...");
69 if (protocol.isRelayed()) {
70 log.info("Protocol is marked relayed.");
71 return true;
72 }
73
74 String remoteHost= ((InetSocketAddress ) protocol.getSock().getRemoteSocketAddress()).getAddress().getHostAddress();
75 if (acl.isValidRelay(remoteHost)) {
76 log.info("ACL said remote is to be relayed.");
77 return true;
78 }
79
80 if (!performSmtpCheck(protocol)) {
81 log.error("I could not contact any smtp servers for domain "+protocol.getMail().getFrom().getHost());
82 return true;
84 }
85
86 }
87
88 return false;
89 }
90 public String getWelcome() {
91 return null;
92 }
93
94
99 private boolean performSmtpCheck (IProtocolHandler protocol) throws IOException {
100 String domain = protocol.getMail().getFrom().getHost();
101 List <InetAddress > mxs= resolver.doMXLookup(domain);
102 if ((mxs==null) || (mxs.size()==0)) {
103 log.error("There are no MX configured for the domain "+domain+", rejecting DATA command");
104 return false;
105 }
106
107 for (InetAddress address : mxs) {
108 log.debug("trying mx "+address);
109 if (checkSmtpServer(address,protocol.getMail().getFrom().toString())) {
110 log.debug("success with mx "+address);
111 return true;
112 }
113 }
114 log.error("Smtp check(s) failed, data not allowed.");
115 return false;
116 }
117
118 private boolean checkSmtpServer (InetAddress smtpAdress, String targetRcpt) {
119 try {
120 Socket client = new Socket ();
121 client.setSoTimeout(30*1000);
122 SocketAddress sockaddr = new InetSocketAddress (smtpAdress.getHostAddress(), 25);
123 client.connect(sockaddr);
124 client.close();
125 return true;
126 } catch (Exception e) {
127 log.error("Error connecting to "+smtpAdress.getHostAddress(),e);
128 }
129
130 return false;
131 }
132
133 public String getPluginName() {
134 return "Callback on DATA verifier";
135 }
136
137 public void initPlugin() throws PluginInitException {
138 acl = PluginStore.getInstance().getAcl();
139 if (acl==null) {
140 log.error("Could not get ACL plugin !");
141 throw new PluginInitException("Could not get ACL plugin");
142 }
143 resolver = PluginStore.getInstance().getResolver();
144 if (resolver==null) {
145 log.error("Could not get Resolver plugin !");
146 throw new PluginInitException("Could not get Resolver plugin");
147 }
148 }
149
150 public void shutdownPlugin() {
151 }
152
153 }
154 |
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