1 files changed, 125 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/mail/receive/Pop3MailReceiver.java b/java/com/google/gerrit/server/mail/receive/Pop3MailReceiver.java
new file mode 100644
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+++ b/java/com/google/gerrit/server/mail/receive/Pop3MailReceiver.java
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+// Copyright (C) 2016 The Android Open Source Project
+//
+// Licensed 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 com.google.gerrit.server.mail.receive;
+
+import com.google.common.flogger.FluentLogger;
+import com.google.common.primitives.Ints;
+import com.google.gerrit.mail.MailMessage;
+import com.google.gerrit.mail.MailParsingException;
+import com.google.gerrit.mail.RawMailParser;
+import com.google.gerrit.server.git.WorkQueue;
+import com.google.gerrit.server.mail.EmailSettings;
+import com.google.gerrit.server.mail.Encryption;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import org.apache.commons.net.pop3.POP3Client;
+import org.apache.commons.net.pop3.POP3MessageInfo;
+import org.apache.commons.net.pop3.POP3SClient;
+
+/** An implementation of {@link MailReceiver} for POP3. */
+@Singleton
+public class Pop3MailReceiver extends MailReceiver {
+  private static final FluentLogger logger = FluentLogger.forEnclosingClass();
+
+  @Inject
+  Pop3MailReceiver(EmailSettings mailSettings, MailProcessor mailProcessor, WorkQueue workQueue) {
+    super(mailSettings, mailProcessor, workQueue);
+  }
+
+  /**
+   * Opens a connection to the mail server, removes emails where deletion is pending, reads new
+   * email and closes the connection.
+   *
+   * @param async determines if processing messages should happen asynchronously
+   * @throws MailTransferException in case of a known transport failure
+   * @throws IOException in case of a low-level transport failure
+   */
+  @Override
+  public synchronized void handleEmails(boolean async) throws MailTransferException, IOException {
+    POP3Client pop3;
+    if (mailSettings.encryption != Encryption.NONE) {
+      pop3 = new POP3SClient(mailSettings.encryption.name(), true);
+    } else {
+      pop3 = new POP3Client();
+    }
+    if (mailSettings.port > 0) {
+      pop3.setDefaultPort(mailSettings.port);
+    }
+    pop3.connect(mailSettings.host);
+    try {
+      if (!pop3.login(mailSettings.username, mailSettings.password)) {
+        throw new MailTransferException(
+            "Could not login to POP3 email server. Check username and password");
+      }
+      try {
+        POP3MessageInfo[] messages = pop3.listMessages();
+        if (messages == null) {
+          throw new MailTransferException("Could not retrieve message list via POP3");
+        }
+        logger.atInfo().log("Received %d messages via POP3", messages.length);
+        // Fetch messages
+        List<MailMessage> mailMessages = new ArrayList<>();
+        for (POP3MessageInfo msginfo : messages) {
+          if (msginfo == null) {
+            // Message was deleted
+            continue;
+          }
+          try (BufferedReader reader = (BufferedReader) pop3.retrieveMessage(msginfo.number)) {
+            if (reader == null) {
+              throw new MailTransferException(
+                  "Could not retrieve POP3 message header for message " + msginfo.identifier);
+            }
+            int[] message = fetchMessage(reader);
+            MailMessage mailMessage = RawMailParser.parse(message);
+            // Delete messages where deletion is pending. This requires
+            // knowing the integer message ID of the email. We therefore parse
+            // the message first and extract the Message-ID specified in RFC
+            // 822 and delete the message if deletion is pending.
+            if (pendingDeletion.contains(mailMessage.id())) {
+              if (pop3.deleteMessage(msginfo.number)) {
+                pendingDeletion.remove(mailMessage.id());
+              } else {
+                logger.atSevere().log("Could not delete message %d", msginfo.number);
+              }
+            } else {
+              // Process message further
+              mailMessages.add(mailMessage);
+            }
+          } catch (MailParsingException e) {
+            logger.atSevere().log("Could not parse message %d", msginfo.number);
+          }
+        }
+        dispatchMailProcessor(mailMessages, async);
+      } finally {
+        pop3.logout();
+      }
+    } finally {
+      pop3.disconnect();
+    }
+  }
+
+  public final int[] fetchMessage(BufferedReader reader) throws IOException {
+    List<Integer> character = new ArrayList<>();
+    int ch;
+    while ((ch = reader.read()) != -1) {
+      character.add(ch);
+    }
+    return Ints.toArray(character);
+  }
+}