4 files changed, 286 insertions, 152 deletions

diff --git a/src/include/gnunet_protocols.h b/src/include/gnunet_protocols.h
index 27a7034b0..7a089ad65 100644
--- a/src/include/gnunet_protocols.h
+++ b/src/include/gnunet_protocols.h
@@ -1089,10 +1089,18 @@ extern "C" {
 
 /**
  * Message telling transport to limit its receive rate.
+ * (FIXME: was the above comment ever accurate?)
+ *
+ * Note: dead in TNG, replaced by RECV_OK!
  */
 #define GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA 366
 
 /**
+ * Message telling transport to limit its receive rate.
+ */
+#define GNUNET_MESSAGE_TYPE_TRANSPORT_RECV_OK 366
+
+/**
  * Request to look addresses of peers in server.
  */
 #define GNUNET_MESSAGE_TYPE_TRANSPORT_ADDRESS_TO_STRING 367
diff --git a/src/include/gnunet_transport_communication_service.h b/src/include/gnunet_transport_communication_service.h
index ca5a86074..ea1ff732e 100644
--- a/src/include/gnunet_transport_communication_service.h
+++ b/src/include/gnunet_transport_communication_service.h
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     Copyright (C) 2009-2018 GNUnet e.V.
+     Copyright (C) 2009-2019 GNUnet e.V.
 
      GNUnet is free software: you can redistribute it and/or modify it
      under the terms of the GNU Affero General Public License as published
@@ -36,9 +36,8 @@
 #define GNUNET_TRANSPORT_COMMUNICATION_SERVICE_H
 
 #ifdef __cplusplus
-extern "C"
-{
-#if 0                           /* keep Emacsens' auto-indent happy */
+extern "C" {
+#if 0 /* keep Emacsens' auto-indent happy */
 }
 #endif
 #endif
@@ -67,12 +66,13 @@ extern "C"
  * @param peer identity of the other peer
  * @param address where to send the message, human-readable
  *        communicator-specific format, 0-terminated, UTF-8
- * @return #GNUNET_OK on success, #GNUNET_SYSERR if the provided address is invalid
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR if the provided address is
+ * invalid
  */
-typedef int
-(*GNUNET_TRANSPORT_CommunicatorMqInit) (void *cls,
-                                        const struct GNUNET_PeerIdentity *peer,
-                                        const char *address);
+typedef int (*GNUNET_TRANSPORT_CommunicatorMqInit) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *peer,
+  const char *address);
 
 
 /**
@@ -87,7 +87,8 @@ struct GNUNET_TRANSPORT_CommunicatorHandle;
  * FIXME: may want to distinguish bi-directional as well,
  * should we define a bit for that? Needed in DV logic (handle_dv_learn)!
  */
-enum GNUNET_TRANSPORT_CommunicatorCharacteristics {
+enum GNUNET_TRANSPORT_CommunicatorCharacteristics
+{
 
   /**
    * Characteristics are unknown (i.e. DV).
@@ -122,10 +123,10 @@ enum GNUNET_TRANSPORT_CommunicatorCharacteristics {
  * @param sender which peer sent the notification
  * @param msg payload
  */
-typedef void
-(*GNUNET_TRANSPORT_CommunicatorNotify) (void *cls,
-                                        const struct GNUNET_PeerIdentity *sender,
-                                        const struct GNUNET_MessageHeader *msg);
+typedef void (*GNUNET_TRANSPORT_CommunicatorNotify) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *sender,
+  const struct GNUNET_MessageHeader *msg);
 
 
 /**
@@ -145,14 +146,15 @@ typedef void
  * @return NULL on error
  */
 struct GNUNET_TRANSPORT_CommunicatorHandle *
-GNUNET_TRANSPORT_communicator_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                                       const char *config_section_name,
-                                       const char *addr_prefix,
-                                       enum GNUNET_TRANSPORT_CommunicatorCharacteristics cc,
-                                       GNUNET_TRANSPORT_CommunicatorMqInit mq_init,
-                                       void *mq_init_cls,
-                                       GNUNET_TRANSPORT_CommunicatorNotify notify_cb,
-                                       void *notify_cb_cls);
+GNUNET_TRANSPORT_communicator_connect (
+  const struct GNUNET_CONFIGURATION_Handle *cfg,
+  const char *config_section_name,
+  const char *addr_prefix,
+  enum GNUNET_TRANSPORT_CommunicatorCharacteristics cc,
+  GNUNET_TRANSPORT_CommunicatorMqInit mq_init,
+  void *mq_init_cls,
+  GNUNET_TRANSPORT_CommunicatorNotify notify_cb,
+  void *notify_cb_cls);
 
 
 /**
@@ -161,22 +163,23 @@ GNUNET_TRANSPORT_communicator_connect (const struct GNUNET_CONFIGURATION_Handle
  * @param ch handle returned from connect
  */
 void
-GNUNET_TRANSPORT_communicator_disconnect (struct GNUNET_TRANSPORT_CommunicatorHandle *ch);
+GNUNET_TRANSPORT_communicator_disconnect (
+  struct GNUNET_TRANSPORT_CommunicatorHandle *ch);
 
 
 /* ************************* Receiving *************************** */
 
 /**
  * Function called to notify communicator that we have received
- * and processed the message.
+ * and processed the message.  Used for flow control (if supported
+ * by the communicator).
  *
  * @param cls closure
  * @param success #GNUNET_SYSERR on failure (try to disconnect/reset connection)
  *                #GNUNET_OK on success
  */
-typedef void
-(*GNUNET_TRANSPORT_MessageCompletedCallback) (void *cls,
-                                              int success);
+typedef void (*GNUNET_TRANSPORT_MessageCompletedCallback) (void *cls,
+                                                           int success);
 
 
 /**
@@ -200,12 +203,13 @@ typedef void
  *         the tranport service is not yet up
  */
 int
-GNUNET_TRANSPORT_communicator_receive (struct GNUNET_TRANSPORT_CommunicatorHandle *handle,
-                                       const struct GNUNET_PeerIdentity *sender,
-                                       const struct GNUNET_MessageHeader *msg,
-                                       struct GNUNET_TIME_Relative expected_addr_validity,
-                                       GNUNET_TRANSPORT_MessageCompletedCallback cb,
-                                       void *cb_cls);
+GNUNET_TRANSPORT_communicator_receive (
+  struct GNUNET_TRANSPORT_CommunicatorHandle *handle,
+  const struct GNUNET_PeerIdentity *sender,
+  const struct GNUNET_MessageHeader *msg,
+  struct GNUNET_TIME_Relative expected_addr_validity,
+  GNUNET_TRANSPORT_MessageCompletedCallback cb,
+  void *cb_cls);
 
 
 /* ************************* Discovery *************************** */
@@ -220,7 +224,8 @@ struct GNUNET_TRANSPORT_QueueHandle;
 /**
  * Possible states of a connection.
  */
-enum GNUNET_TRANSPORT_ConnectionStatus {
+enum GNUNET_TRANSPORT_ConnectionStatus
+{
 
   /**
    * Connection is down.
@@ -255,13 +260,14 @@ enum GNUNET_TRANSPORT_ConnectionStatus {
  * @return API handle identifying the new MQ
  */
 struct GNUNET_TRANSPORT_QueueHandle *
-GNUNET_TRANSPORT_communicator_mq_add (struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
-                                      const struct GNUNET_PeerIdentity *peer,
-                                      const char *address,
-                                      uint32_t mtu,
-                                      enum GNUNET_NetworkType nt,
-                                      enum GNUNET_TRANSPORT_ConnectionStatus cs,
-                                      struct GNUNET_MQ_Handle *mq);
+GNUNET_TRANSPORT_communicator_mq_add (
+  struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
+  const struct GNUNET_PeerIdentity *peer,
+  const char *address,
+  uint32_t mtu,
+  enum GNUNET_NetworkType nt,
+  enum GNUNET_TRANSPORT_ConnectionStatus cs,
+  struct GNUNET_MQ_Handle *mq);
 
 
 /**
@@ -291,10 +297,11 @@ struct GNUNET_TRANSPORT_AddressIdentifier;
  * @param expiration when does the communicator forsee this address expiring?
  */
 struct GNUNET_TRANSPORT_AddressIdentifier *
-GNUNET_TRANSPORT_communicator_address_add (struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
-                                           const char *address,
-                                           enum GNUNET_NetworkType nt,
-                                           struct GNUNET_TIME_Relative expiration);
+GNUNET_TRANSPORT_communicator_address_add (
+  struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
+  const char *address,
+  enum GNUNET_NetworkType nt,
+  struct GNUNET_TIME_Relative expiration);
 
 
 /**
@@ -304,7 +311,8 @@ GNUNET_TRANSPORT_communicator_address_add (struct GNUNET_TRANSPORT_CommunicatorH
  * @param ai address that is no longer provided
  */
 void
-GNUNET_TRANSPORT_communicator_address_remove (struct GNUNET_TRANSPORT_AddressIdentifier *ai);
+GNUNET_TRANSPORT_communicator_address_remove (
+  struct GNUNET_TRANSPORT_AddressIdentifier *ai);
 
 
 /**
@@ -326,13 +334,14 @@ GNUNET_TRANSPORT_communicator_address_remove (struct GNUNET_TRANSPORT_AddressIde
  *        notify-API to @a pid's communicator @a comm
  */
 void
-GNUNET_TRANSPORT_communicator_notify (struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
-                                      const struct GNUNET_PeerIdentity *pid,
-                                      const char *comm,
-                                      const struct GNUNET_MessageHeader *header);
+GNUNET_TRANSPORT_communicator_notify (
+  struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
+  const struct GNUNET_PeerIdentity *pid,
+  const char *comm,
+  const struct GNUNET_MessageHeader *header);
 
 
-#if 0                           /* keep Emacsens' auto-indent happy */
+#if 0 /* keep Emacsens' auto-indent happy */
 {
 #endif
 #ifdef __cplusplus
@@ -342,6 +351,6 @@ GNUNET_TRANSPORT_communicator_notify (struct GNUNET_TRANSPORT_CommunicatorHandle
 /* ifndef GNUNET_TRANSPORT_COMMUNICATOR_SERVICE_H */
 #endif
 
-/** @} */  /* end of group */
+/** @} */ /* end of group */
 
 /* end of gnunet_transport_communicator_service.h */
diff --git a/src/include/gnunet_transport_core_service.h b/src/include/gnunet_transport_core_service.h
index f442b53c0..076514779 100644
--- a/src/include/gnunet_transport_core_service.h
+++ b/src/include/gnunet_transport_core_service.h
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     Copyright (C) 2009-2016 GNUnet e.V.
+     Copyright (C) 2009-2019 GNUnet e.V.
 
      GNUnet is free software: you can redistribute it and/or modify it
      under the terms of the GNU Affero General Public License as published
@@ -11,7 +11,7 @@
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      Affero General Public License for more details.
-    
+
      You should have received a copy of the GNU Affero General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
@@ -21,7 +21,7 @@
  * @author Christian Grothoff
  *
  * @file
- * API of the transport service towards the CORE service.
+ * API of the transport service towards the CORE service (TNG version)
  *
  * @defgroup transport TRANSPORT service
  * Communication with other peers
@@ -34,9 +34,8 @@
 #define GNUNET_TRANSPORT_CORE_SERVICE_H
 
 #ifdef __cplusplus
-extern "C"
-{
-#if 0                           /* keep Emacsens' auto-indent happy */
+extern "C" {
+#if 0 /* keep Emacsens' auto-indent happy */
 }
 #endif
 #endif
@@ -62,15 +61,15 @@ struct GNUNET_TRANSPORT_CoreHandle;
  * @param cls closure
  * @param peer the identity of the peer that connected; this
  *        pointer will remain valid until the disconnect, hence
- *        applications do not necessarily have to make a copy 
+ *        applications do not necessarily have to make a copy
  *        of the value if they only need it until disconnect
  * @param mq message queue to use to transmit to @a peer
  * @return closure to use in MQ handlers
  */
-typedef void *
-(*GNUNET_TRANSPORT_NotifyConnect) (void *cls,
-                                   const struct GNUNET_PeerIdentity *peer,
-                                   struct GNUNET_MQ_Handle *mq);
+typedef void *(*GNUNET_TRANSPORT_NotifyConnect) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *peer,
+  struct GNUNET_MQ_Handle *mq);
 
 
 /**
@@ -84,33 +83,10 @@ typedef void *
  * @param handlers_cls closure of the handlers, was returned from the
  *                    connect notification callback
  */
-typedef void
-(*GNUNET_TRANSPORT_NotifyDisconnect) (void *cls,
-                                      const struct GNUNET_PeerIdentity *peer,
-                                      void *handler_cls);
-
-
-/**
- * Function called if we have "excess" bandwidth to a peer.
- * The notification will happen the first time we have excess
- * bandwidth, and then only again after the client has performed
- * some transmission to the peer.
- *
- * Excess bandwidth is defined as being allowed (by ATS) to send
- * more data, and us reaching the limit of the capacity build-up
- * (which, if we go past it, means we don't use available bandwidth).
- * See also the "max carry" in `struct GNUNET_BANDWIDTH_Tracker`.
- *
- * @param cls the closure
- * @param neighbour peer that we have excess bandwidth to
- * @param handlers_cls closure of the handlers, was returned from the
- *                    connect notification callback
- */
-typedef void
-(*GNUNET_TRANSPORT_NotifyExcessBandwidth)(void *cls,
-                                          const struct GNUNET_PeerIdentity *neighbour,
-                                          void *handlers_cls);
-
+typedef void (*GNUNET_TRANSPORT_NotifyDisconnect) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *peer,
+  void *handler_cls);
 
 
 /**
@@ -136,8 +112,7 @@ GNUNET_TRANSPORT_core_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
                                const struct GNUNET_MQ_MessageHandler *handlers,
                                void *cls,
                                GNUNET_TRANSPORT_NotifyConnect nc,
-                               GNUNET_TRANSPORT_NotifyDisconnect nd,
-                               GNUNET_TRANSPORT_NotifyExcessBandwidth neb);
+                               GNUNET_TRANSPORT_NotifyDisconnect nd);
 
 
 /**
@@ -150,7 +125,33 @@ GNUNET_TRANSPORT_core_disconnect (struct GNUNET_TRANSPORT_CoreHandle *handle);
 
 
 /**
+ * Notification from the CORE service to the TRANSPORT service
+ * that the CORE service has finished processing a message from
+ * TRANSPORT (via the @code{handlers} of #GNUNET_TRANSPORT_core_connect())
+ * and that it is thus now OK for TRANSPORT to send more messages
+ * for @a pid.
+ *
+ * Used to provide flow control, this is our equivalent to
+ * #GNUNET_SERVICE_client_continue() of an ordinary service.
+ *
+ * Note that due to the use of a window, TRANSPORT may send multiple
+ * messages destined for the same peer even without an intermediate
+ * call to this function. However, CORE must still call this function
+ * once per message received, as otherwise eventually the window will
+ * be full and TRANSPORT will stop providing messages to CORE for @a
+ * pid.
+ *
+ * @param ch core handle
+ * @param pid which peer was the message from that was fully processed by CORE
+ */
+void
+GNUNET_TRANSPORT_core_receive_continue (struct GNUNET_TRANSPORT_CoreHandle *ch,
+                                        const struct GNUNET_PeerIdentity *pid);
+
+
+/**
  * Checks if a given peer is connected to us and get the message queue.
+ * Convenience function.
  *
  * @param handle connection to transport service
  * @param peer the peer to check
@@ -161,7 +162,7 @@ GNUNET_TRANSPORT_core_get_mq (struct GNUNET_TRANSPORT_CoreHandle *handle,
                               const struct GNUNET_PeerIdentity *peer);
 
 
-#if 0                           /* keep Emacsens' auto-indent happy */
+#if 0 /* keep Emacsens' auto-indent happy */
 {
 #endif
 #ifdef __cplusplus
@@ -171,6 +172,6 @@ GNUNET_TRANSPORT_core_get_mq (struct GNUNET_TRANSPORT_CoreHandle *handle,
 /* ifndef GNUNET_TRANSPORT_CORE_SERVICE_H */
 #endif
 
-/** @} */  /* end of group */
+/** @} */ /* end of group */
 
 /* end of gnunet_transport_core_service.h */
diff --git a/src/include/gnunet_transport_service.h b/src/include/gnunet_transport_service.h
index c5cb10ad8..80949b417 100644
--- a/src/include/gnunet_transport_service.h
+++ b/src/include/gnunet_transport_service.h
@@ -11,7 +11,7 @@
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      Affero General Public License for more details.
-    
+
      You should have received a copy of the GNU Affero General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
@@ -36,9 +36,8 @@
 #define GNUNET_TRANSPORT_SERVICE_H
 
 #ifdef __cplusplus
-extern "C"
-{
-#if 0                           /* keep Emacsens' auto-indent happy */
+extern "C" {
+#if 0 /* keep Emacsens' auto-indent happy */
 }
 #endif
 #endif
@@ -71,8 +70,8 @@ struct GNUNET_TRANSPORT_OfferHelloHandle;
  *      tc reason #GNUNET_SCHEDULER_REASON_TIMEOUT for fail
  *      tc reasong #GNUNET_SCHEDULER_REASON_READ_READY for success
  * @param cont_cls closure for @a cont
- * @return a `struct GNUNET_TRANSPORT_OfferHelloHandle` handle or NULL on failure,
- *      in case of failure @a cont will not be called
+ * @return a `struct GNUNET_TRANSPORT_OfferHelloHandle` handle or NULL on
+ * failure, in case of failure @a cont will not be called
  *
  */
 struct GNUNET_TRANSPORT_OfferHelloHandle *
@@ -88,7 +87,8 @@ GNUNET_TRANSPORT_offer_hello (const struct GNUNET_CONFIGURATION_Handle *cfg,
  * @param ohh the `struct GNUNET_TRANSPORT_OfferHelloHandle` to cancel
  */
 void
-GNUNET_TRANSPORT_offer_hello_cancel (struct GNUNET_TRANSPORT_OfferHelloHandle *ohh);
+GNUNET_TRANSPORT_offer_hello_cancel (
+  struct GNUNET_TRANSPORT_OfferHelloHandle *ohh);
 
 
 /* *********************** Address to String ******************* */
@@ -115,10 +115,9 @@ struct GNUNET_TRANSPORT_AddressToStringContext;
  *        if #GNUNET_NO: address was invalid (or not supported)
  *        if #GNUNET_SYSERR: communication error (IPC error)
  */
-typedef void
-(*GNUNET_TRANSPORT_AddressToStringCallback) (void *cls,
-                                             const char *address,
-                                             int res);
+typedef void (*GNUNET_TRANSPORT_AddressToStringCallback) (void *cls,
+                                                          const char *address,
+                                                          int res);
 
 
 /**
@@ -134,12 +133,13 @@ typedef void
  * @return handle to cancel the operation, NULL on error
  */
 struct GNUNET_TRANSPORT_AddressToStringContext *
-GNUNET_TRANSPORT_address_to_string (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                                    const struct GNUNET_HELLO_Address *address,
-                                    int numeric,
-                                    struct GNUNET_TIME_Relative timeout,
-                                    GNUNET_TRANSPORT_AddressToStringCallback aluc,
-                                    void *aluc_cls);
+GNUNET_TRANSPORT_address_to_string (
+  const struct GNUNET_CONFIGURATION_Handle *cfg,
+  const struct GNUNET_HELLO_Address *address,
+  int numeric,
+  struct GNUNET_TIME_Relative timeout,
+  GNUNET_TRANSPORT_AddressToStringCallback aluc,
+  void *aluc_cls);
 
 
 /**
@@ -148,14 +148,16 @@ GNUNET_TRANSPORT_address_to_string (const struct GNUNET_CONFIGURATION_Handle *cf
  * @param alc the context handle
  */
 void
-GNUNET_TRANSPORT_address_to_string_cancel (struct GNUNET_TRANSPORT_AddressToStringContext *alc);
+GNUNET_TRANSPORT_address_to_string_cancel (
+  struct GNUNET_TRANSPORT_AddressToStringContext *alc);
 
 
 /* *********************** Monitoring ************************** */
 
 
 /**
- * Possible state of a neighbour.  Initially, we are #GNUNET_TRANSPORT_PS_NOT_CONNECTED.
+ * Possible state of a neighbour.  Initially, we are
+ * #GNUNET_TRANSPORT_PS_NOT_CONNECTED.
  *
  * Then, there are two main paths. If we receive a SYN message, we give
  * the inbound address to ATS. After the check we ask ATS for a suggestion
@@ -174,14 +176,14 @@ GNUNET_TRANSPORT_address_to_string_cancel (struct GNUNET_TRANSPORT_AddressToStri
  * #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
- * SYN message.  If we receive a
- * SYN_ACK, we go to #GNUNET_TRANSPORT_PS_CONNECTED and nobody noticed that we had
- * trouble; we also send a 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).
+ * 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 SYN
+ * message.  If we receive a SYN_ACK, we go to #GNUNET_TRANSPORT_PS_CONNECTED
+ * and nobody noticed that we had trouble; we also send a 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_SYN_SENT
@@ -189,13 +191,14 @@ GNUNET_TRANSPORT_address_to_string_cancel (struct GNUNET_TRANSPORT_AddressToStri
  * primary connection to the suggested alternative from ATS, go back
  * to #GNUNET_TRANSPORT_PS_CONNECTED and send a 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").
+ * 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.
+ * 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 'SYN' request from the other peer.
@@ -323,12 +326,12 @@ struct GNUNET_TRANSPORT_PeerMonitoringContext;
  * @param state current state this peer is in
  * @param state_timeout timeout for the current state of the peer
  */
-typedef void
-(*GNUNET_TRANSPORT_PeerIterateCallback) (void *cls,
-                                         const struct GNUNET_PeerIdentity *peer,
-                                         const struct GNUNET_HELLO_Address *address,
-                                         enum GNUNET_TRANSPORT_PeerState state,
-                                         struct GNUNET_TIME_Absolute state_timeout);
+typedef void (*GNUNET_TRANSPORT_PeerIterateCallback) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *peer,
+  const struct GNUNET_HELLO_Address *address,
+  enum GNUNET_TRANSPORT_PeerState state,
+  struct GNUNET_TIME_Absolute state_timeout);
 
 
 /**
@@ -352,17 +355,18 @@ typedef void
  * @param cfg configuration to use
  * @param peer a specific peer identity to obtain information for,
  *      NULL for all peers
- * @param one_shot #GNUNET_YES to return the current state and then end (with NULL+NULL),
- *                 #GNUNET_NO to monitor peers continuously
+ * @param one_shot #GNUNET_YES to return the current state and then end (with
+ * NULL+NULL), #GNUNET_NO to monitor peers continuously
  * @param peer_callback function to call with the results
  * @param peer_callback_cls closure for @a peer_callback
  */
 struct GNUNET_TRANSPORT_PeerMonitoringContext *
-GNUNET_TRANSPORT_monitor_peers (const struct GNUNET_CONFIGURATION_Handle *cfg,
-                                const struct GNUNET_PeerIdentity *peer,
-                                int one_shot,
-                                GNUNET_TRANSPORT_PeerIterateCallback peer_callback,
-                                void *peer_callback_cls);
+GNUNET_TRANSPORT_monitor_peers (
+  const struct GNUNET_CONFIGURATION_Handle *cfg,
+  const struct GNUNET_PeerIdentity *peer,
+  int one_shot,
+  GNUNET_TRANSPORT_PeerIterateCallback peer_callback,
+  void *peer_callback_cls);
 
 
 /**
@@ -371,7 +375,8 @@ GNUNET_TRANSPORT_monitor_peers (const struct GNUNET_CONFIGURATION_Handle *cfg,
  * @param pic handle for the request to cancel
  */
 void
-GNUNET_TRANSPORT_monitor_peers_cancel (struct GNUNET_TRANSPORT_PeerMonitoringContext *pic);
+GNUNET_TRANSPORT_monitor_peers_cancel (
+  struct GNUNET_TRANSPORT_PeerMonitoringContext *pic);
 
 
 /* *********************** Blacklisting ************************ */
@@ -389,9 +394,9 @@ struct GNUNET_TRANSPORT_Blacklist;
  * @param pid peer to approve or disapproave
  * @return #GNUNET_OK if the connection is allowed, #GNUNET_SYSERR if not
  */
-typedef int
-(*GNUNET_TRANSPORT_BlacklistCallback) (void *cls,
-                                       const struct GNUNET_PeerIdentity *pid);
+typedef int (*GNUNET_TRANSPORT_BlacklistCallback) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *pid);
 
 
 /**
@@ -539,11 +544,11 @@ struct GNUNET_TRANSPORT_SessionInfo
  *        NULL with @a session being non-NULL if the monitor
  *        was being cancelled while sessions were active
  */
-typedef void
-(*GNUNET_TRANSPORT_SessionMonitorCallback) (void *cls,
-                                            struct GNUNET_TRANSPORT_PluginSession *session,
-                                            void **session_ctx,
-                                            const struct GNUNET_TRANSPORT_SessionInfo *info);
+typedef void (*GNUNET_TRANSPORT_SessionMonitorCallback) (
+  void *cls,
+  struct GNUNET_TRANSPORT_PluginSession *session,
+  void **session_ctx,
+  const struct GNUNET_TRANSPORT_SessionInfo *info);
 
 
 /**
@@ -569,11 +574,122 @@ GNUNET_TRANSPORT_monitor_plugins (const struct GNUNET_CONFIGURATION_Handle *cfg,
  * @param pm handle of the request that is to be cancelled
  */
 void
-GNUNET_TRANSPORT_monitor_plugins_cancel (struct GNUNET_TRANSPORT_PluginMonitor *pm);
+GNUNET_TRANSPORT_monitor_plugins_cancel (
+  struct GNUNET_TRANSPORT_PluginMonitor *pm);
+
+
+/**
+ * Opaque handle to the service.
+ */
+struct GNUNET_TRANSPORT_CoreHandle;
+
+
+/**
+ * Function called to notify transport users that another
+ * peer connected to us.
+ *
+ * @param cls closure
+ * @param peer the identity of the peer that connected; this
+ *        pointer will remain valid until the disconnect, hence
+ *        applications do not necessarily have to make a copy
+ *        of the value if they only need it until disconnect
+ * @param mq message queue to use to transmit to @a peer
+ * @return closure to use in MQ handlers
+ */
+typedef void *(*GNUNET_TRANSPORT_NotifyConnect) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *peer,
+  struct GNUNET_MQ_Handle *mq);
+
+
+/**
+ * Function called to notify transport users that another peer
+ * disconnected from us.  The message queue that was given to the
+ * connect notification will be destroyed and must not be used
+ * henceforth.
+ *
+ * @param cls closure from #GNUNET_TRANSPORT_core_connect
+ * @param peer the peer that disconnected
+ * @param handlers_cls closure of the handlers, was returned from the
+ *                    connect notification callback
+ */
+typedef void (*GNUNET_TRANSPORT_NotifyDisconnect) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *peer,
+  void *handler_cls);
+
+
+/**
+ * Function called if we have "excess" bandwidth to a peer.
+ * The notification will happen the first time we have excess
+ * bandwidth, and then only again after the client has performed
+ * some transmission to the peer.
+ *
+ * Excess bandwidth is defined as being allowed (by ATS) to send
+ * more data, and us reaching the limit of the capacity build-up
+ * (which, if we go past it, means we don't use available bandwidth).
+ * See also the "max carry" in `struct GNUNET_BANDWIDTH_Tracker`.
+ *
+ * @param cls the closure
+ * @param neighbour peer that we have excess bandwidth to
+ * @param handlers_cls closure of the handlers, was returned from the
+ *                    connect notification callback
+ */
+typedef void (*GNUNET_TRANSPORT_NotifyExcessBandwidth) (
+  void *cls,
+  const struct GNUNET_PeerIdentity *neighbour,
+  void *handlers_cls);
+
+
+/**
+ * Connect to the transport service.  Note that the connection may
+ * complete (or fail) asynchronously.
+ *
+ * @param cfg configuration to use
+ * @param self our own identity (API should check that it matches
+ *             the identity found by transport), or NULL (no check)
+ * @param handlers array of message handlers; note that the
+ *                 closures provided will be ignored and replaced
+ *                 with the respective return value from @a nc
+ * @param handlers array with handlers to call when we receive messages, or NULL
+ * @param cls closure for the @a nc, @a nd and @a neb callbacks
+ * @param nc function to call on connect events, or NULL
+ * @param nd function to call on disconnect events, or NULL
+ * @param neb function to call if we have excess bandwidth to a peer, or NULL
+ * @return NULL on error
+ */
+struct GNUNET_TRANSPORT_CoreHandle *
+GNUNET_TRANSPORT_core_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                               const struct GNUNET_PeerIdentity *self,
+                               const struct GNUNET_MQ_MessageHandler *handlers,
+                               void *cls,
+                               GNUNET_TRANSPORT_NotifyConnect nc,
+                               GNUNET_TRANSPORT_NotifyDisconnect nd,
+                               GNUNET_TRANSPORT_NotifyExcessBandwidth neb);
+
+
+/**
+ * Disconnect from the transport service.
+ *
+ * @param handle handle returned from connect
+ */
+void
+GNUNET_TRANSPORT_core_disconnect (struct GNUNET_TRANSPORT_CoreHandle *handle);
 
 
+/**
+ * Checks if a given peer is connected to us and get the message queue.
+ *
+ * @param handle connection to transport service
+ * @param peer the peer to check
+ * @return NULL if disconnected, otherwise message queue for @a peer
+ */
+struct GNUNET_MQ_Handle *
+GNUNET_TRANSPORT_core_get_mq (struct GNUNET_TRANSPORT_CoreHandle *handle,
+                              const struct GNUNET_PeerIdentity *peer);
+
 
-#if 0                           /* keep Emacsens' auto-indent happy */
+#if 0 /* keep Emacsens' auto-indent happy */
 {
 #endif
 #ifdef __cplusplus
@@ -583,6 +699,6 @@ GNUNET_TRANSPORT_monitor_plugins_cancel (struct GNUNET_TRANSPORT_PluginMonitor *
 /* ifndef GNUNET_TRANSPORT_SERVICE_H */
 #endif
 
-/** @} */  /* end of group */
+/** @} */ /* end of group */
 
 /* end of gnunet_transport_service.h */