REST/NAMESTORE: rework API
[oweals/gnunet.git] / src / transport / transport_api2_communication.c
index ffd7f208eec45981c6d960378860cdd1b7d2fe91..6d497c9676e618502d9ab0168a4f4d63aac49fb7 100644 (file)
@@ -14,6 +14,8 @@
 
      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/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
 */
 
 /**
@@ -25,6 +27,7 @@
 #include "gnunet_util_lib.h"
 #include "gnunet_protocols.h"
 #include "gnunet_transport_communication_service.h"
+#include "gnunet_ats_transport_service.h"
 #include "transport.h"
 
 
@@ -177,6 +180,18 @@ struct GNUNET_TRANSPORT_CommunicatorHandle
    */
   void *mq_init_cls;
 
+  /**
+   * Function to call when the transport service receives messages
+   * for a communicator (i.e. for NAT traversal or for non-bidirectional
+   * communicators).
+   */
+  GNUNET_TRANSPORT_CommunicatorNotify notify_cb;
+
+  /**
+   * Closure for @e notify_Cb.
+   */
+  void *notify_cb_cls;
+
   /**
    * Queue to talk to the transport service.
    */
@@ -258,11 +273,6 @@ struct GNUNET_TRANSPORT_QueueHandle
    */
   enum GNUNET_TRANSPORT_ConnectionStatus cs;
 
-  /**
-   * How many hops is the target away (DV-only)
-   */
-  uint32_t distance;
-
   /**
    * ID for this queue when talking to the transport service.
    */
@@ -403,7 +413,6 @@ send_add_queue (struct GNUNET_TRANSPORT_QueueHandle *qh)
   aqm->nt = htonl ((uint32_t) qh->nt);
   aqm->mtu = htonl (qh->mtu);
   aqm->cs = htonl ((uint32_t) qh->cs);
-  aqm->distance = htonl (qh->distance);
   memcpy (&aqm[1],
          qh->address,
          strlen (qh->address) + 1);
@@ -609,15 +618,8 @@ static int
 check_send_msg (void *cls,
                const struct GNUNET_TRANSPORT_SendMessageTo *smt)
 {
-  uint16_t len = ntohs (smt->header.size) - sizeof (*smt);
-  const struct GNUNET_MessageHeader *mh = (const struct GNUNET_MessageHeader *) &smt[1];
-
   (void) cls;
-  if (ntohs (mh->size) != len)
-  {
-    GNUNET_break (0);
-    return GNUNET_SYSERR;
-  }
+  GNUNET_MQ_check_boxed_message (smt);
   return GNUNET_OK;
 }
 
@@ -723,6 +725,46 @@ handle_send_msg (void *cls,
 }
 
 
+/**
+ * Transport service gives us backchannel message. Check if @a bi
+ * is well-formed.
+ *
+ * @param cls our `struct GNUNET_TRANSPORT_CommunicatorHandle *`
+ * @param bi the backchannel message
+ * @return #GNUNET_OK if @a smt is well-formed
+ */
+static int
+check_backchannel_incoming (void *cls,
+                           const struct GNUNET_TRANSPORT_CommunicatorBackchannelIncoming *bi)
+{
+  (void) cls;
+  GNUNET_MQ_check_boxed_message (bi);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Transport service gives us backchannel message. Handle it.
+ *
+ * @param cls our `struct GNUNET_TRANSPORT_CommunicatorHandle *`
+ * @param bi the backchannel message
+ */
+static void
+handle_backchannel_incoming (void *cls,
+                            const struct GNUNET_TRANSPORT_CommunicatorBackchannelIncoming *bi)
+{
+  struct GNUNET_TRANSPORT_CommunicatorHandle *ch = cls;
+
+  if (NULL != ch->notify_cb)
+    ch->notify_cb (ch->notify_cb_cls,
+                  &bi->pid,
+                  (const struct GNUNET_MessageHeader *) &bi[1]);
+  else
+    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+               _("Dropped backchanel message: handler not provided by communicator\n"));
+}
+
+
 /**
  * (re)connect our communicator to the transport service
  *
@@ -744,6 +786,10 @@ reconnect (struct GNUNET_TRANSPORT_CommunicatorHandle *ch)
                           GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_MSG,
                           struct GNUNET_TRANSPORT_SendMessageTo,
                           ch),
+    GNUNET_MQ_hd_var_size (backchannel_incoming,
+                          GNUNET_MESSAGE_TYPE_TRANSPORT_COMMUNICATOR_BACKCHANNEL_INCOMING,
+                          struct GNUNET_TRANSPORT_CommunicatorBackchannelIncoming,
+                          ch),
     GNUNET_MQ_handler_end()
   };
   struct GNUNET_TRANSPORT_CommunicatorAvailableMessage *cam;
@@ -790,6 +836,8 @@ reconnect (struct GNUNET_TRANSPORT_CommunicatorHandle *ch)
  *                the address of another peer, can be NULL if the
  *                communicator only supports receiving messages
  * @param mq_init_cls closure for @a mq_init
+ * @param notify_cb function to pass backchannel messages to communicator
+ * @param notify_cb_cls closure for @a notify_cb
  * @return NULL on error
  */
 struct GNUNET_TRANSPORT_CommunicatorHandle *
@@ -798,7 +846,9 @@ GNUNET_TRANSPORT_communicator_connect (const struct GNUNET_CONFIGURATION_Handle
                                       const char *addr_prefix,
                                        enum GNUNET_TRANSPORT_CommunicatorCharacteristics cc,
                                        GNUNET_TRANSPORT_CommunicatorMqInit mq_init,
-                                       void *mq_init_cls)
+                                       void *mq_init_cls,
+                                       GNUNET_TRANSPORT_CommunicatorNotify notify_cb,
+                                      void *notify_cb_cls)
 {
   struct GNUNET_TRANSPORT_CommunicatorHandle *ch;
 
@@ -808,6 +858,8 @@ GNUNET_TRANSPORT_communicator_connect (const struct GNUNET_CONFIGURATION_Handle
   ch->addr_prefix = addr_prefix;
   ch->mq_init = mq_init;
   ch->mq_init_cls = mq_init_cls;
+  ch->notify_cb = notify_cb;
+  ch->notify_cb_cls = notify_cb_cls;
   ch->cc = cc;
   reconnect (ch);
   if (GNUNET_OK !=
@@ -854,6 +906,9 @@ GNUNET_TRANSPORT_communicator_disconnect (struct GNUNET_TRANSPORT_CommunicatorHa
  * @param sender presumed sender of the message (details to be checked
  *        by higher layers)
  * @param msg the message
+ * @param expected_addr_validity how long does the communicator believe it
+ *        will continue to be able to receive messages from the same address
+ *        on which it received this message?
  * @param cb function to call once handling the message is done, NULL if
  *         flow control is not supported by this communicator
  * @param cb_cls closure for @a cb
@@ -867,6 +922,7 @@ int
 GNUNET_TRANSPORT_communicator_receive (struct GNUNET_TRANSPORT_CommunicatorHandle *ch,
                                        const struct GNUNET_PeerIdentity *sender,
                                        const struct GNUNET_MessageHeader *msg,
+                                       struct GNUNET_TIME_Relative expected_addr_validity,
                                        GNUNET_TRANSPORT_MessageCompletedCallback cb,
                                        void *cb_cls)
 {
@@ -880,24 +936,25 @@ GNUNET_TRANSPORT_communicator_receive (struct GNUNET_TRANSPORT_CommunicatorHandl
        (GNUNET_MQ_get_length (ch->mq) >= ch->max_queue_length) )
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-               "Dropping message: transprot is too slow, queue length %llu exceeded\n",
-               ch->max_queue_length);
+                "Dropping message: transprot is too slow, queue length %llu exceeded\n",
+                ch->max_queue_length);
     return GNUNET_NO;
   }
 
   msize = ntohs (msg->size);
   env = GNUNET_MQ_msg_extra (im,
-                            msize,
-                            GNUNET_MESSAGE_TYPE_TRANSPORT_INCOMING_MSG);
+                             msize,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_INCOMING_MSG);
   if (NULL == env)
   {
     GNUNET_break (0);
     return GNUNET_SYSERR;
   }
+  im->expected_address_validity = GNUNET_TIME_relative_hton (expected_addr_validity);
   im->sender = *sender;
   memcpy (&im[1],
-         msg,
-         msize);
+          msg,
+          msize);
   if (NULL != cb)
   {
     struct FlowControl *fc;
@@ -910,11 +967,11 @@ GNUNET_TRANSPORT_communicator_receive (struct GNUNET_TRANSPORT_CommunicatorHandl
     fc->cb = cb;
     fc->cb_cls = cb_cls;
     GNUNET_CONTAINER_DLL_insert (ch->fc_head,
-                                ch->fc_tail,
-                                fc);
+                                 ch->fc_tail,
+                                 fc);
   }
   GNUNET_MQ_send (ch->mq,
-                 env);
+                  env);
   return GNUNET_OK;
 }
 
@@ -934,7 +991,6 @@ GNUNET_TRANSPORT_communicator_receive (struct GNUNET_TRANSPORT_CommunicatorHandl
  *            sending is not supported, SIZE_MAX for no MTU
  * @param nt which network type does the @a address belong to?
  * @param cc what characteristics does the communicator have?
- * @param distance how many hops does this queue use (DV-only)?
  * @param cs what is the connection status of the queue?
  * @param mq message queue of the @a peer
  * @return API handle identifying the new MQ
@@ -945,7 +1001,6 @@ GNUNET_TRANSPORT_communicator_mq_add (struct GNUNET_TRANSPORT_CommunicatorHandle
                                       const char *address,
                                      uint32_t mtu,
                                       enum GNUNET_NetworkType nt,
-                                      uint32_t distance,
                                      enum GNUNET_TRANSPORT_ConnectionStatus cs,
                                       struct GNUNET_MQ_Handle *mq)
 {
@@ -957,7 +1012,6 @@ GNUNET_TRANSPORT_communicator_mq_add (struct GNUNET_TRANSPORT_CommunicatorHandle
   qh->address = GNUNET_strdup (address);
   qh->nt = nt;
   qh->mtu = mtu;
-  qh->distance = distance;
   qh->cs = cs;
   qh->mq = mq;
   qh->queue_id = ch->queue_gen++;
@@ -1041,4 +1095,48 @@ GNUNET_TRANSPORT_communicator_address_remove (struct GNUNET_TRANSPORT_AddressIde
 }
 
 
+/* ************************* Backchannel *************************** */
+
+
+/**
+ * The communicator asks the transport service to route a message via
+ * a different path to another communicator service at another peer.
+ * This must only be done for special control traffic (as there is no
+ * flow control for this API), such as acknowledgements, and generally
+ * only be done if the communicator is uni-directional (i.e. cannot
+ * send the message back itself).
+ *
+ * @param ch handle of this communicator
+ * @param pid peer to send the message to
+ * @param comm name of the communicator to send the message to
+ * @param header header of the message to transmit and pass via the
+ *        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)
+{
+  struct GNUNET_MQ_Envelope *env;
+  struct GNUNET_TRANSPORT_CommunicatorBackchannel *cb;
+  size_t slen = strlen (comm) + 1;
+  uint16_t mlen = ntohs (header->size);
+
+  GNUNET_assert (mlen + slen + sizeof (*cb) < UINT16_MAX);
+  env = GNUNET_MQ_msg_extra (cb,
+                             slen + mlen,
+                             GNUNET_MESSAGE_TYPE_TRANSPORT_COMMUNICATOR_BACKCHANNEL);
+  cb->pid = *pid;
+  memcpy (&cb[1],
+          header,
+          mlen);
+  memcpy (((char *)&cb[1]) + mlen,
+          comm,
+          slen);
+  GNUNET_MQ_send (ch->mq,
+                  env);
+}
+
+
 /* end of transport_api2_communication.c */