Merge "Disable closing idle Ssh connections again" into stable-2.6

Documentation/config-gerrit.txt

@@ -2368,6 +2368,20 @@ unit suffixes to express their setting:
 +
 By default, 2 minutes.
 
+[[sshd.idleTimeout]]sshd.idleTimeout::
++
+Time in seconds after which the server automatically terminates idle
+connections (or 0 to disable closing of idle connections).  Values
+should use common unit suffixes to express their setting:
++
+* s, sec, second, seconds
+* m, min, minute, minutes
+* h, hr, hour, hours
+* d, day, days
+
++
+By default, 0.
+
 [[sshd.maxConnectionsPerUser]]sshd.maxConnectionsPerUser::
 +
 Maximum number of concurrent SSH sessions that a user account

gerrit-sshd/src/main/java/com/google/gerrit/sshd/SshDaemon.java

@@ -152,6 +152,18 @@ public class SshDaemon extends SshServer implements SshInfo, LifecycleListener {
         String.valueOf(MILLISECONDS.convert(ConfigUtil.getTimeUnit(cfg, "sshd",
             null, "loginGraceTime", 120, SECONDS), SECONDS)));
 
+    long idleTimeoutSeconds = ConfigUtil.getTimeUnit(cfg, "sshd", null,
+        "idleTimeout", 0, SECONDS);
+    if (idleTimeoutSeconds == 0) {
+      // Since Apache SSHD does not allow to turn off closing idle connections,
+      // we fake it by using the highest timeout allowed by Apache SSHD, which
+      // amounts to ~24 days.
+      idleTimeoutSeconds = MILLISECONDS.toSeconds(Integer.MAX_VALUE);
+    }
+    getProperties().put(
+        IDLE_TIMEOUT,
+        String.valueOf(SECONDS.toMillis(idleTimeoutSeconds)));
+
     final int maxConnectionsPerUser =
         cfg.getInt("sshd", "maxConnectionsPerUser", 64);
     if (0 < maxConnectionsPerUser) {