text: /* Copyright (c) 2019, The Tor Project, Inc. */
  /* See LICENSE for licensing information */
  
  /**
   * \file sendme.h
   * \brief Header file for sendme.c.
   **/
  
  #ifndef TOR_SENDME_H
  #define TOR_SENDME_H
  
  #include "core/or/edge_connection_st.h"
  #include "core/or/crypt_path_st.h"
  #include "core/or/circuit_st.h"
  
  /* Sending SENDME cell. */
  void sendme_connection_edge_consider_sending(edge_connection_t *edge_conn);
  void sendme_circuit_consider_sending(circuit_t *circ,
                                       crypt_path_t *layer_hint);
  
  /* Processing SENDME cell. */
  int sendme_process_circuit_level(crypt_path_t *layer_hint,
                                   circuit_t *circ, const uint8_t *cell_payload,
                                   uint16_t cell_payload_len);
  int sendme_process_stream_level(edge_connection_t *conn, circuit_t *circ,
                                  uint16_t cell_body_len);
  
  /* Update deliver window functions. */
  int sendme_stream_data_received(edge_connection_t *conn);
  int sendme_circuit_data_received(circuit_t *circ, crypt_path_t *layer_hint);
  
  /* Update package window functions. */
  int sendme_note_circuit_data_packaged(circuit_t *circ,
                                        crypt_path_t *layer_hint);
  int sendme_note_stream_data_packaged(edge_connection_t *conn);
  
  /* Record cell digest on circuit. */
  void sendme_record_cell_digest_on_circ(circuit_t *circ, crypt_path_t *cpath);
  /* Record cell digest as the SENDME digest. */
  void sendme_record_received_cell_digest(circuit_t *circ, crypt_path_t *cpath);
  void sendme_record_sending_cell_digest(circuit_t *circ, crypt_path_t *cpath);
  
  /* Private section starts. */
  #ifdef SENDME_PRIVATE
  
  /* The maximum supported version. Above that value, the cell can't be
   * recognized as a valid SENDME. */
  #define SENDME_MAX_SUPPORTED_VERSION 1
  
  /* The cell version constants for when emitting a cell. */
  #define SENDME_EMIT_MIN_VERSION_DEFAULT 0
  #define SENDME_EMIT_MIN_VERSION_MIN 0
  #define SENDME_EMIT_MIN_VERSION_MAX UINT8_MAX
  
  /* The cell version constants for when accepting a cell. */
  #define SENDME_ACCEPT_MIN_VERSION_DEFAULT 0
  #define SENDME_ACCEPT_MIN_VERSION_MIN 0
  #define SENDME_ACCEPT_MIN_VERSION_MAX UINT8_MAX
  
  /*
   * Unit tests declaractions.
   */
  #ifdef TOR_UNIT_TESTS
  
  STATIC int get_emit_min_version(void);
  STATIC int get_accept_min_version(void);
  
  STATIC bool cell_version_can_be_handled(uint8_t cell_version);
  
  STATIC ssize_t build_cell_payload_v1(const uint8_t *cell_digest,
                                       uint8_t *payload);
  STATIC bool sendme_is_valid(const circuit_t *circ,
                              const uint8_t *cell_payload,
                              size_t cell_payload_len);
  
  #endif /* TOR_UNIT_TESTS */
  
  #endif /* SENDME_PRIVATE */
  
  #endif /* !defined(TOR_SENDME_H) */
  