4 files changed, 262 insertions, 0 deletions

diff --git a/src/main/java/org/gnunet/transport/PeerState.java b/src/main/java/org/gnunet/transport/PeerState.java
new file mode 100644
index 0000000..538c189
--- /dev/null
+++ b/src/main/java/org/gnunet/transport/PeerState.java
@@ -0,0 +1,148 @@
+/*
+ This file is part of GNUnet.
+  (C) 2014 Christian Grothoff (and other contributing authors)
+
+  GNUnet is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published
+  by the Free Software Foundation; either version 3, or (at your
+  option) any later version.
+
+  GNUnet is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with GNUnet; see the file COPYING.  If not, write to the
+  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+  Boston, MA 02111-1307, USA.
+ */
+
+package org.gnunet.transport;
+
+
+/**
+ * Possible state of a neighbour.  Initially, we are #GNUNET_TRANSPORT_PS_NOT_CONNECTED.
+ *
+ * Then, there are two main paths. If we receive a CONNECT message, we give
+ * the inbound address to ATS. After the check we ask ATS for a suggestion
+ * (#GNUNET_TRANSPORT_PS_CONNECT_RECV_ATS). If ATS makes a suggestion, we
+ * send our CONNECT_ACK and go to #GNUNET_TRANSPORT_PS_CONNECT_RECV_ACK.
+ * If we receive a SESSION_ACK, we go to #GNUNET_TRANSPORT_PS_CONNECTED
+ * (and notify everyone about the new connection). If the operation times out,
+ * we go to #GNUNET_TRANSPORT_PS_DISCONNECT.
+ *
+ * The other case is where we transmit a CONNECT message first.  We
+ * start with #GNUNET_TRANSPORT_PS_INIT_ATS.  If we get an address, we send
+ * the CONNECT message and go to state #GNUNET_TRANSPORT_PS_CONNECT_SENT.
+ * Once we receive a CONNECT_ACK, we go to #GNUNET_TRANSPORT_PS_CONNECTED
+ * (and notify everyone about the new connection and send
+ * back a SESSION_ACK).  If the operation times out, we go to
+ * #GNUNET_TRANSPORT_PS_DISCONNECT.
+ *
+ * If the session is in trouble (i.e. transport-level disconnect or
+ * timeout), we go to #GNUNET_TRANSPORT_PS_RECONNECT_ATS where we ask ATS for a new
+ * address (we don't notify anyone about the disconnect yet).  Once we
+ * have a new address, we enter #GNUNET_TRANSPORT_PS_RECONNECT_SENT and send a
+ * CONNECT message.  If we receive a
+ * CONNECT_ACK, we go to #GNUNET_TRANSPORT_PS_CONNECTED and nobody noticed that we had
+ * trouble; we also send a SESSION_ACK at this time just in case.  If
+ * the operation times out, we go to #GNUNET_TRANSPORT_PS_DISCONNECT (and notify everyone
+ * about the lost connection).
+ *
+ * If ATS decides to switch addresses while we have a normal
+ * connection, we go to #GNUNET_TRANSPORT_PS_CONNECTED_SWITCHING_CONNECT_SENT
+ * and send a SESSION_CONNECT.  If we get a SESSION_ACK back, we switch the
+ * primary connection to the suggested alternative from ATS, go back
+ * to #GNUNET_TRANSPORT_PS_CONNECTED and send a SESSION_ACK to the other peer just to be
+ * sure.  If the operation times out
+ * we go to #GNUNET_TRANSPORT_PS_CONNECTED (and notify ATS that the given alternative
+ * address is "invalid").
+ *
+ * Once a session is in #GNUNET_TRANSPORT_PS_DISCONNECT, it is cleaned up and then goes
+ * to (#GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED).  If we receive an explicit disconnect
+ * request, we can go from any state to #GNUNET_TRANSPORT_PS_DISCONNECT, possibly after
+ * generating disconnect notifications.
+ *
+ * Note that it is quite possible that while we are in any of these
+ * states, we could receive a 'CONNECT' request from the other peer.
+ * We then enter a 'weird' state where we pursue our own primary state
+ * machine (as described above), but with the 'send_connect_ack' flag
+ * set to 1.  If our state machine allows us to send a 'CONNECT_ACK'
+ * (because we have an acceptable address), we send the 'CONNECT_ACK'
+ * and set the 'send_connect_ack' to 2.  If we then receive a
+ * 'SESSION_ACK', we go to #GNUNET_TRANSPORT_PS_CONNECTED (and reset 'send_connect_ack'
+ * to 0).
+ *
+ */
+class PeerState
+{
+  /**
+   * Fresh peer or completely disconnected
+   */
+  public static final int NOT_CONNECTED = 0;
+
+  /**
+   * Asked to initiate connection, trying to get address from ATS
+   */
+  public static final int INIT_ATS = 1;
+
+  /**
+   * Sent CONNECT message to other peer, waiting for CONNECT_ACK
+   */
+  public static final int CONNECT_SENT = 2;
+
+  /**
+   * Received a CONNECT, asking ATS about address suggestions.
+   */
+  public static final int CONNECT_RECV_ATS = 3;
+
+  /**
+   * CONNECT request from other peer was CONNECT_ACK'ed, waiting for
+   * SESSION_ACK.
+   */
+  public static final int CONNECT_RECV_ACK = 4;
+
+  /**
+   * Got our CONNECT_ACK/SESSION_ACK, connection is up.
+   */
+  public static final int CONNECTED = 5;
+
+  /**
+   * Connection got into trouble, rest of the system still believes
+   * it to be up, but we're getting a new address from ATS.
+   */
+  public static final int RECONNECT_ATS = 6;
+
+  /**
+   * Sent CONNECT over new address (either by ATS telling us to switch
+   * addresses or from RECONNECT_ATS); if this fails, we need to tell
+   * the rest of the system about a disconnect.
+   */
+  public static final int RECONNECT_SENT = 7;
+
+  /**
+   * We have some primary connection, but ATS suggested we switch
+   * to some alternative; we now sent a CONNECT message for the
+   * alternative session to the other peer and waiting for a
+   * CONNECT_ACK to make this our primary connection.
+   */
+  public static final int CONNECTED_SWITCHING_CONNECT_SENT = 8;
+
+  /**
+   * Disconnect in progress (we're sending the DISCONNECT message to the
+   * other peer; after that is finished, the state will be cleaned up).
+   */
+  public static final int DISCONNECT = 9;
+
+  /**
+   * We're finished with the disconnect; and are cleaning up the state
+   * now!  We put the struct into this state when we are really in the
+   * task that calls 'free' on it and are about to remove the record
+   * from the map.  We should never find a 'struct NeighbourMapEntry'
+   * in this state in the map.  Accessing a 'struct NeighbourMapEntry'
+   * in this state virtually always means using memory that has been
+   * freed (the exception being the cleanup code in #free_neighbour()).
+   */
+  public static final int DISCONNECT_FINISHED = 10;
+}
diff --git a/src/main/java/org/gnunet/transport/messages/ConnectMessage.java b/src/main/java/org/gnunet/transport/messages/ConnectMessage.java
new file mode 100644
index 0000000..4467926
--- /dev/null
+++ b/src/main/java/org/gnunet/transport/messages/ConnectMessage.java
@@ -0,0 +1,38 @@
+/*
+ This file is part of GNUnet.
+ (C) 2014 Christian Grothoff (and other contributing authors)
+
+ GNUnet is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3, or (at your
+ option) any later version.
+
+ GNUnet is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GNUnet; see the file COPYING.  If not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+ */
+package org.gnunet.transport.messages;
+
+import org.gnunet.construct.*;
+import org.gnunet.util.GnunetMessage;
+import org.gnunet.util.PeerIdentity;
+
+/**
+ * Message from the transport service, notifying the client
+ * about a connected peer.
+ */
+@UnionCase(361)
+public class ConnectMessage implements GnunetMessage.Body {
+  /**
+   * FIXME: just a placeholder.
+   */
+  @FillWith @UInt8
+  public byte[] body;
+}
+
diff --git a/src/main/java/org/gnunet/transport/messages/DisconnectMessage.java b/src/main/java/org/gnunet/transport/messages/DisconnectMessage.java
new file mode 100644
index 0000000..3f63dfc
--- /dev/null
+++ b/src/main/java/org/gnunet/transport/messages/DisconnectMessage.java
@@ -0,0 +1,38 @@
+/*
+ This file is part of GNUnet.
+ (C) 2014 Christian Grothoff (and other contributing authors)
+
+ GNUnet is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3, or (at your
+ option) any later version.
+
+ GNUnet is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GNUnet; see the file COPYING.  If not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+ */
+package org.gnunet.transport.messages;
+
+import org.gnunet.construct.*;
+import org.gnunet.util.GnunetMessage;
+import org.gnunet.util.PeerIdentity;
+
+/**
+ * Message from the transport service, notifying the client
+ * about a disconnected peer.
+ */
+@UnionCase(362)
+public class DisconnectMessage implements GnunetMessage.Body {
+  /**
+   * FIXME: just a placeholder.
+   */
+  @FillWith @UInt8
+  public byte[] body;
+}
+
diff --git a/src/main/java/org/gnunet/transport/messages/RecvMessage.java b/src/main/java/org/gnunet/transport/messages/RecvMessage.java
new file mode 100644
index 0000000..0fb0d26
--- /dev/null
+++ b/src/main/java/org/gnunet/transport/messages/RecvMessage.java
@@ -0,0 +1,38 @@
+/*
+ This file is part of GNUnet.
+ (C) 2014 Christian Grothoff (and other contributing authors)
+
+ GNUnet is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; either version 3, or (at your
+ option) any later version.
+
+ GNUnet is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GNUnet; see the file COPYING.  If not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+ */
+package org.gnunet.transport.messages;
+
+import org.gnunet.construct.*;
+import org.gnunet.util.GnunetMessage;
+import org.gnunet.util.PeerIdentity;
+
+/**
+ * Message from service to client to notify about
+ * a received message.
+ */
+@UnionCase(365)
+public class RecvMessage implements GnunetMessage.Body {
+  /**
+   * FIXME: just a placeholder.
+   */
+  @FillWith @UInt8
+  public byte[] body;
+}
+