MESSENGER: Implement linked deletion of transcript and private message

Signed-off-by: TheJackiMonster <thejackimonster@gmail.com>

5 files changed, 223 insertions, 61 deletions

diff --git a/src/include/gnunet_protocols.h b/src/include/gnunet_protocols.h
index 17aeff63f..42524d490 100644
--- a/src/include/gnunet_protocols.h
+++ b/src/include/gnunet_protocols.h
@@ -1,6 +1,6 @@
 /*
      This file is part of GNUnet.
-     Copyright (C) 2001--2020 GNUnet e.V.
+     Copyright (C) 2001--2024 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
@@ -3560,17 +3560,9 @@ extern "C" {
 
 #define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_CREATE 1600
 
-#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_UPDATE 1601
+#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_DESTROY 1601
 
-#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_DESTROY 1602
-
-#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_GET_NAME 1603
-
-#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_SET_NAME 1604
-
-#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_GET_KEY 1605
-
-#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_MEMBER_ID 1606
+#define GNUNET_MESSAGE_TYPE_MESSENGER_CONNECTION_MEMBER_ID 1602
 
 /************************************  Room  *************************************/
 
@@ -3588,6 +3580,8 @@ extern "C" {
 
 #define GNUNET_MESSAGE_TYPE_MESSENGER_ROOM_SYNC 1617
 
+#define GNUNET_MESSAGE_TYPE_MESSENGER_ROOM_LINK 1618
+
 /*********************************************************************************/
 
 /*********************************************************************************/
diff --git a/src/service/messenger/gnunet-service-messenger.h b/src/service/messenger/gnunet-service-messenger.h
index c3e762734..4d629d2e1 100644
--- a/src/service/messenger/gnunet-service-messenger.h
+++ b/src/service/messenger/gnunet-service-messenger.h
@@ -27,6 +27,7 @@
 #define GNUNET_SERVICE_MESSENGER_H
 
 #include "gnunet_util_lib.h"
+#include <stdint.h>
 
 /**
  * Message to create a handle for a client
@@ -37,14 +38,6 @@ struct GNUNET_MESSENGER_CreateMessage
 };
 
 /**
- * Message to update the handle (its public key) for a client
- */
-struct GNUNET_MESSENGER_UpdateMessage
-{
-  struct GNUNET_MessageHeader header;
-};
-
-/**
  * Message to destroy the handle for a client
  */
 struct GNUNET_MESSENGER_DestroyMessage
@@ -53,22 +46,6 @@ struct GNUNET_MESSENGER_DestroyMessage
 };
 
 /**
- * Message to receive the current name of a handle
- */
-struct GNUNET_MESSENGER_NameMessage
-{
-  struct GNUNET_MessageHeader header;
-};
-
-/**
- * Message to receive the current public key of a handle
- */
-struct GNUNET_MESSENGER_KeyMessage
-{
-  struct GNUNET_MessageHeader header;
-};
-
-/**
  * General message to confirm interaction with a room
  */
 struct GNUNET_MESSENGER_RoomMessage
@@ -127,4 +104,16 @@ struct GNUNET_MESSENGER_RecvMessage
   uint32_t flags;
 };
 
+/**
+ * Message to link something in a room
+ */
+struct GNUNET_MESSENGER_LinkMessage
+{
+  struct GNUNET_MessageHeader header;
+
+  struct GNUNET_HashCode key;
+  struct GNUNET_HashCode hashes [2];
+  uint32_t bidirectional;
+};
+
 #endif //GNUNET_SERVICE_MESSENGER_H
diff --git a/src/service/messenger/messenger_api.c b/src/service/messenger/messenger_api.c
index e69309573..240a5e018 100644
--- a/src/service/messenger/messenger_api.c
+++ b/src/service/messenger/messenger_api.c
@@ -225,6 +225,12 @@ handle_member_id (void *cls,
 }
 
 
+static void
+delete_message_in_room (struct GNUNET_MESSENGER_Room *room,
+                        const struct GNUNET_HashCode *hash,
+                        const struct GNUNET_TIME_Relative delay);
+
+
 static enum GNUNET_GenericReturnValue
 check_recv_message (void *cls,
                     const struct GNUNET_MESSENGER_RecvMessage *msg)
@@ -285,6 +291,8 @@ handle_recv_message (void *cls,
   decode_message (&message, length, buffer, GNUNET_YES, NULL);
 
   struct GNUNET_MESSENGER_Message *private_message = NULL;
+  const struct GNUNET_MESSENGER_Message *handle_msg = &message;
+
   if (GNUNET_MESSENGER_KIND_PRIVATE == message.header.kind)
   {
     private_message = copy_message (&message);
@@ -351,8 +359,25 @@ handle_recv_message (void *cls,
   recipient = get_store_contact(store, context, recipient_key);
 
 skip_recipient:
-  contact = handle_room_message (room, contact, recipient, private_message ?
-                                 private_message : &message, hash, flags);
+  if (private_message)
+    handle_msg = private_message;
+
+  if (GNUNET_MESSENGER_KIND_DELETE == handle_msg->header.kind)
+  {
+    struct GNUNET_TIME_Relative delay;
+    struct GNUNET_TIME_Absolute action;
+
+    delay = GNUNET_TIME_relative_ntoh (handle_msg->body.deletion.delay);
+    
+    action = GNUNET_TIME_absolute_ntoh (handle_msg->header.timestamp);
+    action = GNUNET_TIME_absolute_add (action, delay);
+    
+    delay = GNUNET_TIME_absolute_get_difference (GNUNET_TIME_absolute_get (), action);
+
+    link_room_deletion (room, &(handle_msg->body.deletion.hash), delay, delete_message_in_room);
+  }
+
+  contact = handle_room_message (room, contact, recipient, handle_msg, hash, flags);
 
   const struct GNUNET_MESSENGER_Message *stored_message = get_room_message (
     room, hash);
@@ -693,8 +718,8 @@ GNUNET_MESSENGER_disconnect (struct GNUNET_MESSENGER_Handle *handle)
 static void
 send_message_to_room (struct GNUNET_MESSENGER_Room *room,
                       struct GNUNET_MESSENGER_Message *message,
-                      struct GNUNET_MESSENGER_Message *transcript,
-                      const struct GNUNET_CRYPTO_PrivateKey *key)
+                      const struct GNUNET_CRYPTO_PrivateKey *key,
+                      struct GNUNET_HashCode *hash)
 {
   const struct GNUNET_ShortHashCode *sender_id = get_room_sender_id (room);
 
@@ -723,14 +748,10 @@ send_message_to_room (struct GNUNET_MESSENGER_Room *room,
   char *msg_buffer = ((char*) msg) + sizeof(*msg);
   encode_message (message, msg_length, msg_buffer, GNUNET_YES);
 
-  struct GNUNET_HashCode hash;
-  hash_message (message, msg_length, msg_buffer, &hash);
-  sign_message (message, msg_length, msg_buffer, &hash, key);
-
-  if (transcript)
-    GNUNET_memcpy (&(transcript->body.transcript.hash), &hash, sizeof(hash));
+  hash_message (message, msg_length, msg_buffer, hash);
+  sign_message (message, msg_length, msg_buffer, hash, key);
 
-  GNUNET_memcpy (&(room->last_message), &hash, sizeof(room->last_message));
+  GNUNET_memcpy (&(room->last_message), hash, sizeof(room->last_message));
 
   GNUNET_MQ_send (room->handle->mq, env);
 
@@ -772,13 +793,14 @@ enqueue_message_to_room (struct GNUNET_MESSENGER_Room *room,
 static enum GNUNET_GenericReturnValue
 dequeue_messages_from_room (struct GNUNET_MESSENGER_Room *room)
 {
+  if (GNUNET_YES != is_room_available (room))
+    return room->queue.head ? GNUNET_NO : GNUNET_YES;
+
   struct GNUNET_MESSENGER_Message *message = NULL;
   struct GNUNET_MESSENGER_Message *transcript = NULL;
   struct GNUNET_CRYPTO_PublicKey pubkey;
   struct GNUNET_CRYPTO_PrivateKey key;
-
-  if (GNUNET_YES != is_room_available (room))
-    return room->queue.head ? GNUNET_NO : GNUNET_YES;
+  struct GNUNET_HashCode hash, other;
 
   do {
     if (message)
@@ -792,15 +814,21 @@ dequeue_messages_from_room (struct GNUNET_MESSENGER_Room *room)
       continue;
     }
     
-    send_message_to_room (room, message, transcript, &key);
+    send_message_to_room (room, message, &key, &hash);
 
     if (!transcript)
       continue;
 
-    GNUNET_CRYPTO_key_get_public(&key, &pubkey);
+    GNUNET_memcpy (&(transcript->body.transcript.hash), &hash, sizeof(hash));
+    GNUNET_CRYPTO_key_get_public (&key, &pubkey);
     
     if (GNUNET_YES == encrypt_message(transcript, &pubkey))
-      send_message_to_room (room, transcript, NULL, &key);
+    {
+      send_message_to_room (room, transcript, &key, &other);
+      
+      link_room_message(room, &hash, &other);
+      link_room_message(room, &other, &hash);
+    }
     else
     {
       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
@@ -1210,19 +1238,16 @@ GNUNET_MESSENGER_send_message (struct GNUNET_MESSENGER_Room *room,
   else
     public_key = NULL;
 
-  send_message_to_room_with_key (room, copy_message(message), public_key);
+  send_message_to_room_with_key (room, copy_message (message), public_key);
 }
 
 
-void
-GNUNET_MESSENGER_delete_message (struct GNUNET_MESSENGER_Room *room,
-                                 const struct GNUNET_HashCode *hash,
-                                 const struct GNUNET_TIME_Relative delay)
+static void
+delete_message_in_room (struct GNUNET_MESSENGER_Room *room,
+                        const struct GNUNET_HashCode *hash,
+                        const struct GNUNET_TIME_Relative delay)
 {
-  if ((! room) || (! hash))
-    return;
-
-  struct GNUNET_MESSENGER_Message *message = create_message_delete(hash, delay);
+  struct GNUNET_MESSENGER_Message *message = create_message_delete (hash, delay);
 
   if (! message)
   {
@@ -1235,6 +1260,18 @@ GNUNET_MESSENGER_delete_message (struct GNUNET_MESSENGER_Room *room,
 }
 
 
+void
+GNUNET_MESSENGER_delete_message (struct GNUNET_MESSENGER_Room *room,
+                                 const struct GNUNET_HashCode *hash,
+                                 const struct GNUNET_TIME_Relative delay)
+{
+  if ((! room) || (! hash))
+    return;
+
+  delete_message_in_room (room, hash, delay);
+}
+
+
 const struct GNUNET_MESSENGER_Message*
 GNUNET_MESSENGER_get_message (const struct GNUNET_MESSENGER_Room *room,
                               const struct GNUNET_HashCode *hash)
diff --git a/src/service/messenger/messenger_api_room.c b/src/service/messenger/messenger_api_room.c
index e7de430ae..c66f0e594 100644
--- a/src/service/messenger/messenger_api_room.c
+++ b/src/service/messenger/messenger_api_room.c
@@ -25,6 +25,7 @@
 
 #include "messenger_api_room.h"
 
+#include "gnunet_time_lib.h"
 #include "messenger_api_handle.h"
 #include "messenger_api_message.h"
 
@@ -52,6 +53,7 @@ create_room (struct GNUNET_MESSENGER_Handle *handle,
 
   room->messages = GNUNET_CONTAINER_multihashmap_create (8, GNUNET_NO);
   room->members = GNUNET_CONTAINER_multishortmap_create (8, GNUNET_NO);
+  room->links = GNUNET_CONTAINER_multihashmap_create (8, GNUNET_NO);
 
   init_queue_messages (&(room->queue));
 
@@ -73,6 +75,17 @@ iterate_destroy_message (void *cls,
 }
 
 
+static enum GNUNET_GenericReturnValue
+iterate_destroy_link (void *cls,
+                      const struct GNUNET_HashCode *key,
+                      void *value)
+{
+  struct GNUNET_HashCode *hash = value;
+  GNUNET_free (hash);
+  return GNUNET_YES;
+}
+
+
 void
 destroy_room (struct GNUNET_MESSENGER_Room *room)
 {
@@ -92,6 +105,14 @@ destroy_room (struct GNUNET_MESSENGER_Room *room)
   if (room->members)
     GNUNET_CONTAINER_multishortmap_destroy (room->members);
 
+  if (room->links)
+  {
+    GNUNET_CONTAINER_multihashmap_iterate (room->links,
+                                           iterate_destroy_link, NULL);
+
+    GNUNET_CONTAINER_multihashmap_destroy (room->links);
+  }
+
   if (room->sender_id)
     GNUNET_free (room->sender_id);
 
@@ -513,3 +534,88 @@ find_room_member (const struct GNUNET_MESSENGER_Room *room,
 
   return find.result;
 }
+
+
+static enum GNUNET_GenericReturnValue
+find_linked_hash (void *cls,
+                  const struct GNUNET_HashCode *key,
+                  void *value)
+{
+  const struct GNUNET_HashCode **result = cls;
+  struct GNUNET_HashCode *hash = value;
+
+  if (0 == GNUNET_CRYPTO_hash_cmp (hash, *result))
+  {
+    *result = NULL;
+    return GNUNET_NO;
+  }
+
+  return GNUNET_YES;
+}
+
+
+void
+link_room_message (struct GNUNET_MESSENGER_Room *room,
+                   const struct GNUNET_HashCode *hash,
+                   const struct GNUNET_HashCode *other)
+{
+  GNUNET_assert ((room) && (hash) && (other));
+
+  const struct GNUNET_HashCode **result = &other;
+  GNUNET_CONTAINER_multihashmap_get_multiple (room->links, hash, 
+                                              find_linked_hash, result);
+
+  if (! *result)
+    return;
+
+  struct GNUNET_HashCode *value = GNUNET_memdup(other, sizeof(struct GNUNET_HashCode));
+  if (! value)
+    return;
+
+  if (GNUNET_OK != GNUNET_CONTAINER_multihashmap_put (room->links, hash, value, 
+                                                      GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE))
+    GNUNET_free (value);
+}
+
+
+struct GNUNET_MESSENGER_RoomLinkDeletionInfo
+{
+  struct GNUNET_MESSENGER_Room *room;
+  struct GNUNET_TIME_Relative delay;
+  GNUNET_MESSENGER_RoomLinkDeletion deletion;
+};
+
+
+static enum GNUNET_GenericReturnValue
+delete_linked_hash (void *cls,
+                    const struct GNUNET_HashCode *key,
+                    void *value)
+{
+  struct GNUNET_MESSENGER_RoomLinkDeletionInfo *info = cls;
+  struct GNUNET_HashCode *hash = value;
+
+  if (info->deletion)
+    info->deletion (info->room, hash, info->delay);
+
+  GNUNET_free (hash);
+  return GNUNET_YES;
+}
+
+
+void
+link_room_deletion (struct GNUNET_MESSENGER_Room *room,
+                    const struct GNUNET_HashCode *hash,
+                    const struct GNUNET_TIME_Relative delay,
+                    GNUNET_MESSENGER_RoomLinkDeletion deletion)
+{
+  GNUNET_assert ((room) && (hash));
+
+  struct GNUNET_MESSENGER_RoomLinkDeletionInfo info;
+  info.room = room;
+  info.delay = delay;
+  info.deletion = deletion;
+
+  GNUNET_CONTAINER_multihashmap_get_multiple (room->links, hash, 
+                                              delete_linked_hash, &info);
+  GNUNET_CONTAINER_multihashmap_remove_all (room->links, hash);
+}
diff --git a/src/service/messenger/messenger_api_room.h b/src/service/messenger/messenger_api_room.h
index 855405337..79571bc2e 100644
--- a/src/service/messenger/messenger_api_room.h
+++ b/src/service/messenger/messenger_api_room.h
@@ -26,6 +26,8 @@
 #ifndef GNUNET_MESSENGER_API_ROOM_H
 #define GNUNET_MESSENGER_API_ROOM_H
 
+#include "gnunet_common.h"
+#include "gnunet_time_lib.h"
 #include "gnunet_util_lib.h"
 
 #include "gnunet_messenger_service.h"
@@ -58,10 +60,15 @@ struct GNUNET_MESSENGER_Room
 
   struct GNUNET_CONTAINER_MultiHashMap *messages;
   struct GNUNET_CONTAINER_MultiShortmap *members;
+  struct GNUNET_CONTAINER_MultiHashMap *links;
 
   struct GNUNET_MESSENGER_QueueMessages queue;
 };
 
+typedef void (*GNUNET_MESSENGER_RoomLinkDeletion) (struct GNUNET_MESSENGER_Room *room,
+                                                   const struct GNUNET_HashCode *hash,
+                                                   const struct GNUNET_TIME_Relative delay);
+
 /**
  * Creates and allocates a new room for a <i>handle</i> with a given <i>key</i> for the client API.
  *
@@ -194,4 +201,33 @@ enum GNUNET_GenericReturnValue
 find_room_member (const struct GNUNET_MESSENGER_Room *room,
                   const struct GNUNET_MESSENGER_Contact *contact);
 
+/**
+ * Links a message identified by its <i>hash</i> inside a given <i>room</i> with another
+ * message identified by its <i>other</i> hash. Linked messages will be deleted automatically,
+ * if any linked message to it gets deleted.
+ *
+ * @param[in,out] room Room
+ * @param[in] hash Hash of message
+ * @param[in] other Hash of other message
+ */
+void
+link_room_message (struct GNUNET_MESSENGER_Room *room,
+                   const struct GNUNET_HashCode *hash,
+                   const struct GNUNET_HashCode *other);
+
+/**
+ * Delete all remaining links to a certain message identified by its <i>hash</i> inside a given
+ * <i>room</i> and cause a <i>deletion</i> process to all of the linked messages.
+ *
+ * @param[in,out] room Room
+ * @param[in] hash Hash of message
+ * @param[in] delay Delay for linked deletion
+ * @param[in] deletion Function called for each linked deletion 
+ */
+void
+link_room_deletion (struct GNUNET_MESSENGER_Room *room,
+                    const struct GNUNET_HashCode *hash,
+                    const struct GNUNET_TIME_Relative delay,
+                    GNUNET_MESSENGER_RoomLinkDeletion deletion);
+
 #endif //GNUNET_MESSENGER_API_ROOM_H