I2CP: More fixes after prop, w.r.t. restore after close-on-idle

- When socket is closed, set sessionID and LS to null,
    close subsession and set its sessionID and LS to null
  - Checks on client side for null session ID
  - Check for null session in Destroy Session message
  - Don't kill I2CP connection due to a bad session ID
    in a SendMessage, just drop the message and send
    a MessageStatusMessage
  - Log tweaks

core/java/src/net/i2p/client/I2CPMessageProducer.java

@@ -34,6 +34,7 @@ import net.i2p.data.i2cp.ReportAbuseMessage;
 import net.i2p.data.i2cp.SendMessageMessage;
 import net.i2p.data.i2cp.SendMessageExpiresMessage;
 import net.i2p.data.i2cp.SessionConfig;
+import net.i2p.data.i2cp.SessionId;
 import net.i2p.util.Log;
 
 /**
@@ -154,7 +155,12 @@ class I2CPMessageProducer {
         } else
             msg = new SendMessageMessage();
         msg.setDestination(dest);
-        msg.setSessionId(session.getSessionId());
+        SessionId sid = session.getSessionId();
+        if (sid == null) {
+            _log.error(session.toString() + " send message w/o session", new Exception());
+            return;
+        }
+        msg.setSessionId(sid);
         msg.setNonce(nonce);
         Payload data = createPayload(dest, payload, null, null, null, null);
         msg.setPayload(data);
@@ -176,7 +182,12 @@ class I2CPMessageProducer {
             return;
         SendMessageMessage msg = new SendMessageExpiresMessage(options);
         msg.setDestination(dest);
-        msg.setSessionId(session.getSessionId());
+        SessionId sid = session.getSessionId();
+        if (sid == null) {
+            _log.error(session.toString() + " send message w/o session", new Exception());
+            return;
+        }
+        msg.setSessionId(sid);
         msg.setNonce(nonce);
         Payload data = createPayload(dest, payload, null, null, null, null);
         msg.setPayload(data);
@@ -352,7 +363,12 @@ class I2CPMessageProducer {
         msg.setLeaseSet(leaseSet);
         msg.setPrivateKey(priv);
         msg.setSigningPrivateKey(signingPriv);
-        msg.setSessionId(session.getSessionId());
+        SessionId sid = session.getSessionId();
+        if (sid == null) {
+            _log.error(session.toString() + " create LS w/o session", new Exception());
+            return;
+        }
+        msg.setSessionId(sid);
         session.sendMessage(msg);
     }
 
@@ -381,7 +397,12 @@ class I2CPMessageProducer {
             throw new I2PSessionException("Unable to sign the session config", dfe);
         }
         msg.setSessionConfig(cfg);
-        msg.setSessionId(session.getSessionId());
+        SessionId sid = session.getSessionId();
+        if (sid == null) {
+            _log.error(session.toString() + " update config w/o session", new Exception());
+            return;
+        }
+        msg.setSessionId(sid);
         session.sendMessage(msg);
     }
 }

core/java/src/net/i2p/client/I2PSessionImpl.java

@@ -502,6 +502,8 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
     }
 
     protected void changeState(State state) {
+        if (_log.shouldInfo())
+            _log.info(getPrefix() + "Change state to " + state);
         synchronized (_stateLock) {
             _state = state;
             _stateLock.notifyAll();
@@ -891,8 +893,9 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
     public void messageReceived(I2CPMessageReader reader, I2CPMessage message) {
         int type = message.getType();
         SessionId id = message.sessionId();
-        if (id == null || id.equals(_sessionId) ||
-            (_sessionId == null && id != null && type == SessionStatusMessage.MESSAGE_TYPE)) {
+        SessionId currId = _sessionId;
+        if (id == null || id.equals(currId) ||
+            (currId == null && id != null && type == SessionStatusMessage.MESSAGE_TYPE)) {
             // it's for us
             I2CPMessageHandler handler = _handlerMap.getHandler(type);
             if (handler != null) {
@@ -1123,6 +1126,13 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
             locked_closeSocket();
             changeState(State.CLOSED);
         }
+        synchronized (_subsessionLock) {
+            for (SubSession sess : _subsessions) {
+                sess.changeState(State.CLOSED);
+                sess.setSessionId(null);
+                sess.setLeaseSet(null);
+            }
+        }
     }
 
     /**
@@ -1152,6 +1162,8 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
                 _socket = null; // so when propogateError calls closeSocket, it doesnt loop
             }
         }
+        setSessionId(null);
+        setLeaseSet(null);
     }
 
     /**
@@ -1238,8 +1250,10 @@ public abstract class I2PSessionImpl implements I2PSession, I2CPMessageReader.I2
             buf.append(s);
         else
             buf.append(getClass().getSimpleName());
-        if (_sessionId != null)
-            buf.append(" #").append(_sessionId.getSessionId());
+        SessionId id = _sessionId;
+        if (id != null)
+            buf.append(" #").append(id.getSessionId());
+        buf.append(' ').append(_state.toString());
         buf.append("]: ");
         return buf.toString();
     }