add assertion to make static analysis happy
[oweals/gnunet.git] / src / cadet / cadet_protocol.h
index ba2044b0d8a1943a8416963282469d200c1e1620..d2426addbd67cad26531acdea192034093c3f244 100644 (file)
@@ -56,20 +56,23 @@ GNUNET_NETWORK_STRUCT_BEGIN
 /**
  * Message for cadet connection creation.
  */
-struct GNUNET_CADET_ConnectionCreate
+struct GNUNET_CADET_ConnectionCreateMessage
 {
   /**
    * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE
    *
-   * Size: sizeof (struct GNUNET_CADET_ConnectionCreate) +
+   * Size: sizeof (struct GNUNET_CADET_ConnectionCreateMessage) +
    *       path_length * sizeof (struct GNUNET_PeerIdentity)
    */
   struct GNUNET_MessageHeader header;
 
   /**
-   * For alignment.
+   * Connection options in network byte order.
+   * #GNUNET_CADET_OPTION_DEFAULT for buffered;
+   * #GNUNET_CADET_OPTION_NOBUFFER for unbuffered.
+   * Other flags are ignored and should not be set at this level.
    */
-  uint32_t reserved GNUNET_PACKED;
+  uint32_t options GNUNET_PACKED;
 
   /**
    * ID of the connection
@@ -87,10 +90,10 @@ struct GNUNET_CADET_ConnectionCreate
 /**
  * Message for ack'ing a connection
  */
-struct GNUNET_CADET_ConnectionACK
+struct GNUNET_CADET_ConnectionCreateAckMessage
 {
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_ACK
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_CREATE_ACK
    */
   struct GNUNET_MessageHeader header;
 
@@ -110,10 +113,10 @@ struct GNUNET_CADET_ConnectionACK
 /**
  * Message for notifying a disconnection in a path
  */
-struct GNUNET_CADET_ConnectionBroken
+struct GNUNET_CADET_ConnectionBrokenMessage
 {
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_BROKEN.
    */
   struct GNUNET_MessageHeader header;
 
@@ -142,7 +145,7 @@ struct GNUNET_CADET_ConnectionBroken
 /**
  * Message to destroy a connection.
  */
-struct GNUNET_CADET_ConnectionDestroy
+struct GNUNET_CADET_ConnectionDestroyMessage
 {
   /**
    * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_DESTROY
@@ -161,56 +164,27 @@ struct GNUNET_CADET_ConnectionDestroy
 };
 
 
-/**
- * Message to acknowledge cadet encrypted traffic.
- */
-struct GNUNET_CADET_ACK
-{
-  /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_ACK
-   */
-  struct GNUNET_MessageHeader header;
-
-  /**
-   * Maximum packet ID authorized.
-   */
-  uint32_t ack GNUNET_PACKED;
-
-  /**
-   * ID of the connection.
-   */
-  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
-};
-
+/******************************************************************************/
+/*******************************   TUNNEL   ***********************************/
+/******************************************************************************/
 
 /**
- * Message to query a peer about its Flow Control status regarding a tunnel.
+ * Unique identifier (counter) for an encrypted message in a channel.
+ * Used to match #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK
+ * and  #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED_POLL messages
+ * against the respective  #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED
+ * messages.
  */
-struct GNUNET_CADET_Poll
+struct CadetEncryptedMessageIdentifier
 {
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_POLL
-   */
-  struct GNUNET_MessageHeader header;
-
-  /**
-   * Last packet sent.
+   * This number is incremented by one per message. It may wrap around.
+   * In network byte order.
    */
   uint32_t pid GNUNET_PACKED;
-
-  /**
-   * ID of the connection.
-   */
-  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
-
 };
 
 
-
-/******************************************************************************/
-/*******************************   TUNNEL   ***********************************/
-/******************************************************************************/
-
 /**
  * Flags to be used in GNUNET_CADET_KX.
  */
@@ -231,10 +205,12 @@ enum GNUNET_CADET_KX_Flags {
 /**
  * Message for a Key eXchange for a tunnel.
  */
-struct GNUNET_CADET_KX
+struct GNUNET_CADET_TunnelKeyExchangeMessage
 {
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_KX.
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX or
+   * #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_KX_AUTH as part
+   * of `struct GNUNET_CADET_TunnelKeyExchangeAuthMessage`.
    */
   struct GNUNET_MessageHeader header;
 
@@ -262,23 +238,77 @@ struct GNUNET_CADET_KX
    * using 'gcry_sexp_sprint'.
    */
   struct GNUNET_CRYPTO_EcdhePublicKey ratchet_key;
+
+};
+
+
+/**
+ * Message for a Key eXchange for a tunnel, with authentication.
+ * Used as a response to the initial KX as well as for rekeying.
+ */
+struct GNUNET_CADET_TunnelKeyExchangeAuthMessage
+{
+
+  /**
+   * Message header with key material.
+   */
+  struct GNUNET_CADET_TunnelKeyExchangeMessage kx;
+
+  /**
+   * KDF-proof that sender could compute the 3-DH, used in lieu of a
+   * signature or payload data.
+   */
+  struct GNUNET_HashCode auth;
+
 };
 
 
 /**
- * Axolotl tunnel message.
+ * Encrypted axolotl header with numbers that identify which
+ * keys in which ratchet are to be used to decrypt the body.
  */
-struct GNUNET_CADET_Encrypted
+struct GNUNET_CADET_AxHeader
 {
+
+  /**
+   * Number of messages sent with the current ratchet key.
+   */
+  uint32_t Ns GNUNET_PACKED;
+
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_ENCRYPTED
+   * Number of messages sent with the previous ratchet key.
+   */
+  uint32_t PNs GNUNET_PACKED;
+
+  /**
+   * Current ratchet key.
+   */
+  struct GNUNET_CRYPTO_EcdhePublicKey DHRs;
+
+};
+
+
+/**
+ * Axolotl-encrypted tunnel message with application payload.
+ */
+struct GNUNET_CADET_TunnelEncryptedMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED
    */
   struct GNUNET_MessageHeader header;
 
+#if NEW_CADET
   /**
-   * ID of the packet (hop by hop).
+   * Reserved, for alignment.
    */
-  uint32_t pid GNUNET_PACKED;
+  uint32_t reserved GNUNET_PACKED;
+#else
+  /**
+   * Maximum packet ID authorized.
+   */
+  struct CadetEncryptedMessageIdentifier cemi;
+#endif
 
   /**
    * ID of the connection.
@@ -290,10 +320,15 @@ struct GNUNET_CADET_Encrypted
    * Everything after this value  will be encrypted with the header key
    * and authenticated.
    */
-  struct GNUNET_CADET_Hash hmac;
-
-  /**************** AX_HEADER start ****************/
+  struct GNUNET_ShortHashCode hmac;
 
+  #if NEW_CADET
+  /**
+   * Axolotl-header that specifies which keys to use in which ratchet
+   * to decrypt the body that follows.
+   */
+  struct GNUNET_CADET_AxHeader ax_header;
+#else
   /**
    * Number of messages sent with the current ratchet key.
    */
@@ -308,15 +343,67 @@ struct GNUNET_CADET_Encrypted
    * Current ratchet key.
    */
   struct GNUNET_CRYPTO_EcdhePublicKey DHRs;
+#endif
+  /**
+   * Encrypted content follows.
+   */
+};
 
-  /**************** AX_HEADER  end  ****************/
 
+#ifndef NEW_CADET
+
+/**
+ * Message to query a peer about its Flow Control status regarding a tunnel.
+ *
+ * It is NOT yet clear if we need this.
+ */
+struct GNUNET_CADET_ConnectionHopByHopPollMessage
+{
   /**
-   * Encrypted content follows.
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_TUNNEL_ENCRYPTED_POLL
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Last packet sent.
    */
+  struct CadetEncryptedMessageIdentifier cemi;
+
+  /**
+   * ID of the connection.
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+
 };
 
 
+/**
+ * Message to acknowledge cadet encrypted traffic, used for
+ * flow-control on a hop-by-hop basis on the connection-level. Note
+ * that we do use the @e cemi from the tunnel layer as the connection
+ * layer's header is included/shared with the tunnel layer messages,
+ * and we only do flow control for the payload.
+ */
+struct GNUNET_CADET_ConnectionEncryptedAckMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CONNECTION_HOP_BY_HOP_ENCRYPTED_ACK
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Maximum packet ID authorized.
+   */
+  struct CadetEncryptedMessageIdentifier cemi_max;
+
+  /**
+   * ID of the connection.
+   */
+  struct GNUNET_CADET_ConnectionTunnelIdentifier cid;
+};
+
+#endif
+
 
 /******************************************************************************/
 /*******************************   CHANNEL  ***********************************/
@@ -326,10 +413,10 @@ struct GNUNET_CADET_Encrypted
 /**
  * Message to create a Channel.
  */
-struct GNUNET_CADET_ChannelCreate
+struct GNUNET_CADET_ChannelOpenMessage
 {
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_CREATE
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN
    */
   struct GNUNET_MessageHeader header;
 
@@ -344,33 +431,45 @@ struct GNUNET_CADET_ChannelCreate
   struct GNUNET_HashCode port;
 
   /**
-   * ID of the channel
+   * ID of the channel within the tunnel.
    */
-  struct GNUNET_CADET_ChannelNumber chid;
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
 };
 
 
 /**
- * Message to manage a Channel (ACK, NACK, Destroy).
+ * Message to manage a Channel
+ * (#GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK,
+ * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY).
  */
-struct GNUNET_CADET_ChannelManage
+struct GNUNET_CADET_ChannelManageMessage
 {
   /**
-   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_{ACK|NACK|DESTROY}
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_OPEN_ACK or
+   * #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_DESTROY
    */
   struct GNUNET_MessageHeader header;
 
+#ifdef NEW_CADET
+  /**
+   * For alignment.
+   */
+  uint32_t reserved GNUNET_PACKED;
+#endif
+
   /**
    * ID of the channel
    */
-  struct GNUNET_CADET_ChannelNumber chid;
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
 };
 
 
+#ifndef NEW_CADET
+
 /**
  * Message for cadet data traffic.
  */
-struct GNUNET_CADET_Data
+struct GNUNET_CADET_ChannelAppDataMessage
 {
   /**
    * Type: #GNUNET_MESSAGE_TYPE_CADET_UNICAST,
@@ -381,12 +480,13 @@ struct GNUNET_CADET_Data
   /**
    * Unique ID of the payload message
    */
+  /* NEW: struct ChannelMessageIdentifier */
   uint32_t mid GNUNET_PACKED;
 
   /**
    * ID of the channel
    */
-  struct GNUNET_CADET_ChannelNumber chid;
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
 
   /**
    * Payload follows
@@ -397,20 +497,20 @@ struct GNUNET_CADET_Data
 /**
  * Message to acknowledge end-to-end data.
  */
-struct GNUNET_CADET_DataACK
+struct GNUNET_CADET_ChannelDataAckMessage
 {
   /**
-   * Type: GNUNET_MESSAGE_TYPE_CADET_DATA_ACK
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK
    */
   struct GNUNET_MessageHeader header;
 
   /**
    * ID of the channel
    */
-  struct GNUNET_CADET_ChannelNumber chid;
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
 
   /**
-   * Bitfield of already-received newer messages
+   * Bitfield of already-received messages past @e mid.
    * pid +  1 @ LSB
    * pid + 64 @ MSB
    */
@@ -419,11 +519,84 @@ struct GNUNET_CADET_DataACK
   /**
    * Last message ID received.
    */
+  /* NEW: struct ChannelMessageIdentifier */
   uint32_t mid GNUNET_PACKED;
 };
 
+#else
 
 
+/**
+ * Number used to uniquely identify messages in a CADET Channel.
+ */
+struct ChannelMessageIdentifier
+{
+  /**
+   * Unique ID of the message, cycles around, in NBO.
+   */
+  uint32_t mid GNUNET_PACKED;
+};
+
+
+/**
+ * Message for cadet data traffic.
+ */
+struct GNUNET_CADET_ChannelAppDataMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA.
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * Unique ID of the payload message.
+   */
+  struct ChannelMessageIdentifier mid;
+
+  /**
+   * ID of the channel
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+
+  /**
+   * Payload follows
+   */
+};
+
+
+/**
+ * Message to acknowledge end-to-end data.
+ */
+struct GNUNET_CADET_ChannelDataAckMessage
+{
+  /**
+   * Type: #GNUNET_MESSAGE_TYPE_CADET_CHANNEL_APP_DATA_ACK
+   */
+  struct GNUNET_MessageHeader header;
+
+  /**
+   * ID of the channel
+   */
+  struct GNUNET_CADET_ChannelTunnelNumber ctn;
+
+  /**
+   * Bitfield of already-received newer messages.  Note that bit 0
+   * corresponds to @e mid + 1.
+   *
+   * pid +  0 @ LSB
+   * pid + 63 @ MSB
+   */
+  uint64_t futures GNUNET_PACKED;
+
+  /**
+   * Next message ID expected.
+   */
+  struct ChannelMessageIdentifier mid;
+};
+
+
+#endif
+
 GNUNET_NETWORK_STRUCT_END
 
 #if 0                           /* keep Emacsens' auto-indent happy */