src/org/ibex/mail/protocol/SMTP.java

   1 package org.ibex.mail.protocol;
   2 import org.ibex.mail.*;
   3 import org.ibex.mail.target.*;
   4 import org.ibex.util.*;
   5 import org.ibex.io.*;
   6 import org.ibex.net.*;
   7 import java.net.*;
   8 import java.io.*;
   9 import java.util.*;
  10 import java.text.*;
  11 import javax.naming.*;
  12 import javax.naming.directory.*;
  13
  14 // FEATURE: exponential backoff on retry time?
  15 public class SMTP {
  16
  17     private static final Mailbox spool =
  18         FileBasedMailbox.getFileBasedMailbox(Mailbox.STORAGE_ROOT,false).slash("spool",true).slash("smtp",true);
  19
  20     static { new Thread() { public void run() { Outgoing.runq(); } }.start(); }
  21
  22     // Server //////////////////////////////////////////////////////////////////////////////
  23
  24     public static class Server implements Worker {
  25         public void handleRequest(Connection conn) {
  26             conn.setTimeout(5 * 60 * 1000);
  27             conn.out.println("220 " + conn.vhost + " SMTP " + this.getClass().getName());
  28             Address from = null;
  29             Vector to = new Vector();
  30             for(String command = conn.in.readln(); ; command = conn.in.readln()) {
  31                 String c = command.toUpperCase();
  32                 if (c.startsWith("HELO"))        { conn.out.println("250 HELO " + conn.vhost); from = null; to = new Vector();
  33                 } else if (c.startsWith("EHLO")) { conn.out.println("250");                    from = null; to = new Vector();
  34                 } else if (c.startsWith("RSET")) { conn.out.println("250 reset ok");           from = null; to = new Vector();
  35                 } else if (c.startsWith("HELP")) { conn.out.println("214 you are beyond help.  see a trained professional.");
  36                 } else if (c.startsWith("VRFY")) { conn.out.println("252 We don't VRFY; proceed anyway");
  37                 } else if (c.startsWith("EXPN")) { conn.out.println("550 EXPN not available");
  38                 } else if (c.startsWith("NOOP")) { conn.out.println("250 OK");
  39                 } else if (c.startsWith("QUIT")) { conn.out.println("221 " + conn.vhost + " closing connection"); return;
  40                 } else if (c.startsWith("MAIL FROM:")) {
  41                     conn.out.println("250 " + (from = new Address(command.substring(10).trim())) + " is syntactically correct");
  42                 } else if (c.startsWith("RCPT TO:")) {
  43                     if (from == null) { conn.out.println("503 MAIL FROM must precede RCPT TO"); continue; }
  44                     command = command.substring(8).trim();
  45                     if(command.indexOf(' ') != -1) command = command.substring(0, command.indexOf(' '));
  46                     Address addr = new Address(command);
  47                     InetAddress[] mx = getMailExchangerIPs(addr.host);
  48                     to.addElement(addr);
  49                     if (conn.getRemoteAddress().isLoopbackAddress()) {
  50                         conn.out.println("250 you are connected locally, so I will let you send");
  51                     } else {
  52                         boolean good = false;
  53                         for(int i=0; !good && i<mx.length; i++) {
  54                             try {
  55                                 if (NetworkInterface.getByInetAddress(mx[i]) != null) good = true;
  56                             } catch (Exception e) { /* DELIBERATE */ }
  57                         }
  58                         if (!good) { conn.out.println("551 sorry, " + addr + " is not on this machine"); return; }
  59                         conn.out.println("250 " + addr + " is on this machine; I will deliver it");
  60                     }
  61                 } else if (c.startsWith("DATA")) {
  62                     if (from == null) { conn.out.println("503 MAIL FROM command must precede DATA"); continue; }
  63                     if (to == null) { conn.out.println("503 RCPT TO command must precede DATA"); continue; }
  64                     conn.out.println("354 Enter message, ending with \".\" on a line by itself");
  65                     try {
  66                         StringBuffer buf = new StringBuffer();
  67                         for(String s = conn.in.readln(); ; s = conn.in.readln()) {
  68                             if (s == null) throw new RuntimeException("connection closed");
  69                             if (s.equals(".")) break;
  70                             if (s.startsWith(".")) s = s.substring(1);
  71                             buf.append(s);
  72                         }
  73                         String body = buf.toString();
  74                         for(int i=0; i<to.size(); i++) {
  75                             Message m = new Message(from, (Address)to.elementAt(i), new Stream(body));
  76                             Target.root.accept(m);
  77                         }
  78                         conn.out.println("250 message accepted");
  79                         from = null; to = new Vector();
  80                     } catch (MailException.Malformed mfe) {   conn.out.println("501 " + mfe.toString());
  81                     } catch (MailException.MailboxFull mbf) { conn.out.println("452 " + mbf);
  82                     } catch (IOException ioe) {               conn.out.println("554 " + ioe.toString());
  83                     }
  84                 } else                           { conn.out.println("500 unrecognized command"); }
  85             }
  86         }
  87     }
  88
  89
  90     // Outgoing Mail Thread //////////////////////////////////////////////////////////////////////////////
  91
  92     public static class Outgoing {
  93         private static final HashSet deadHosts = new HashSet();
  94         public static void send(Message m) throws IOException {
  95             if (m.traces.length >= 100)
  96                 Log.warn(SMTP.Outgoing.class, "Message with " + m.traces.length + " trace hops; dropping\n" + m.summary());
  97             else synchronized(Outgoing.class) {
  98                 spool.add(m);
  99                 Outgoing.class.notify();
 100             }
 101         }
 102
 103         private static boolean attempt(Message m) throws IOException {
 104             InetAddress[] mx = getMailExchangerIPs(m.envelopeTo.host);
 105             if (mx.length == 0) {
 106                 Log.warn(SMTP.Outgoing.class, "could not resolve " + m.envelopeTo.host + "; bouncing it\n" + m.summary());
 107                 send(m.bounce("could not resolve " + m.envelopeTo.host));
 108                 return true;
 109             }
 110             if (new Date().getTime() - m.arrival.getTime() > 1000 * 60 * 60 * 24 * 5) {
 111                 Log.warn(SMTP.Outgoing.class, "could not send message after 5 days; bouncing it\n" + m.summary());
 112                 send(m.bounce("could not send for 5 days"));
 113                 return true;
 114             }
 115             for(int i=0; i<mx.length; i++) {
 116                 if (deadHosts.contains(mx[i])) continue;
 117                 if (attempt(m, mx[i])) { return true; }
 118             }
 119             return false;
 120         }
 121
 122         private static void check(String s) { if (s.startsWith("4")||s.startsWith("5")) throw new MailException(s); }
 123         private static boolean attempt(final Message m, final InetAddress mx) {
 124             boolean accepted = false;
 125             try {
 126                 Log.info(SMTP.Outgoing.class, "connecting...");
 127                 Connection conn = new Connection(new Socket(mx, 25), InetAddress.getLocalHost().getHostName());
 128                 Log.info(SMTP.Outgoing.class, "connected");
 129                 check(conn.in.readln());  // banner
 130                 conn.out.println("HELO " + conn.vhost);            check(conn.in.readln());
 131                 conn.out.println("MAIL FROM: " + m.envelopeFrom);  check(conn.in.readln());
 132                 conn.out.println("RCPT TO: " + m.envelopeTo);      check(conn.in.readln());
 133                 conn.out.println("DATA");                          check(conn.in.readln());
 134                 conn.out.println(m.body);
 135                 conn.out.println(".");
 136                 check(conn.in.readln());
 137                 Log.info(SMTP.Outgoing.class, "message accepted by " + mx);
 138                 accepted = true;
 139                 conn.close();
 140             } catch (Exception e) {
 141                 if (accepted) return true;
 142                 Log.warn(SMTP.Outgoing.class, "unable to send; error=" + e);
 143                 Log.warn(SMTP.Outgoing.class, e);
 144                 return false;
 145             } finally { Log.setThreadAnnotation("[outgoing smtp] "); }
 146             return accepted;
 147         }
 148
 149         static void runq() {
 150             try {
 151                 Log.setThreadAnnotation("[outgoing smtp] ");
 152                 Log.info(SMTP.Outgoing.class, "outgoing thread started; " + spool.count(Query.all()) + " messages to send");
 153                 while(true) {
 154                     for(Mailbox.Iterator it = spool.iterator(); it.next(); )
 155                         try                   { if (attempt(it.cur())) it.delete(); }
 156                         catch (IOException e) { Log.error(SMTP.Outgoing.class, e); }
 157                     synchronized(Outgoing.class) {
 158                         Log.info(SMTP.Outgoing.class, "outgoing thread going to sleep");
 159                         Outgoing.class.wait(10 * 60 * 1000);
 160                         deadHosts.clear();
 161                         Log.info(SMTP.Outgoing.class,"outgoing thread woke up; "+spool.count(Query.all())+" messages in queue");
 162                     }
 163                 }
 164             } catch (Exception e) { Log.error(SMTP.Outgoing.class, e); }
 165         }
 166     }
 167
 168     public static InetAddress[] getMailExchangerIPs(String hostName) {
 169         InetAddress[] ret;
 170         try {
 171             Hashtable env = new Hashtable();
 172             env.put("java.naming.factory.initial", "com.sun.jndi.dns.DnsContextFactory");
 173             DirContext ictx = new InitialDirContext(env);
 174             Attributes attrs = ictx.getAttributes(hostName, new String[] { "MX" });
 175             Attribute attr = attrs.get("MX");
 176             if (attr == null) {
 177                 ret = new InetAddress[1];
 178                 try {
 179                     ret[0] = InetAddress.getByName(hostName);
 180                     return ret;
 181                 } catch (UnknownHostException uhe) {
 182                     Log.warn(SMTP.class, "no MX hosts or A record for " + hostName);
 183                     return new InetAddress[0];
 184                 }
 185             } else {
 186                 ret = new InetAddress[attr.size()];
 187                 NamingEnumeration ne = attr.getAll();
 188                 for(int i=0; ne.hasMore(); i++) {
 189                     String mx = (String)ne.next();
 190                     // FIXME we should be sorting here
 191                     mx = mx.substring(mx.indexOf(" ") + 1);
 192                     if (mx.charAt(mx.length() - 1) == '.') mx = mx.substring(0, mx.length() - 1);
 193                     ret[i] = InetAddress.getByName(mx);
 194                 }
 195             }
 196         } catch (Exception e) {
 197             Log.warn(SMTP.class, "couldn't find MX host for " + hostName + " due to");
 198             Log.warn(SMTP.class, e);
 199             return new InetAddress[0];
 200         }
 201         return ret;
 202     }
 203 }