tor

The Tor anonymity network
git clone https://git.dasho.dev/tor.git
Log | Files | Refs | README | LICENSE

msgtypes.h (2079B)

      1 /* Copyright (c) 2001, Matej Pfajfar.
      2 * Copyright (c) 2001-2004, Roger Dingledine.
      3 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
      4 * Copyright (c) 2007-2021, The Tor Project, Inc. */
      5 /* See LICENSE for licensing information */
      6 
      7 /**
      8 * \file msgtypes.h
      9 * \brief Types used for messages in the dispatcher code.
     10 **/
     11 
     12 #ifndef TOR_DISPATCH_MSGTYPES_H
     13 #define TOR_DISPATCH_MSGTYPES_H
     14 
     15 #include <stdint.h>
     16 
     17 #include "ext/tor_queue.h"
     18 
     19 /**
     20 * These types are aliases for subsystems, channels, and message IDs.
     21 **/
     22 typedef uint16_t subsys_id_t;
     23 typedef uint16_t channel_id_t;
     24 typedef uint16_t message_id_t;
     25 
     26 /**
     27 * This identifies a C type that can be sent along with a message.
     28 **/
     29 typedef uint16_t msg_type_id_t;
     30 
     31 /**
     32 * An ID value returned for *_type_t when none exists.
     33 */
     34 #define ERROR_ID 65535
     35 
     36 /**
     37 * Auxiliary (untyped) data sent along with a message.
     38 *
     39 * We define this as a union of a pointer and a u64, so that the integer
     40 * types will have the same range across platforms.
     41 **/
     42 typedef union {
     43  void *ptr;
     44  uint64_t u64;
     45 } msg_aux_data_t;
     46 
     47 /**
     48 * Structure of a received message.
     49 **/
     50 typedef struct msg_t {
     51  TOR_SIMPLEQ_ENTRY(msg_t) next;
     52  subsys_id_t sender;
     53  channel_id_t channel;
     54  message_id_t msg;
     55  /** We could omit this field, since it is implicit in the message type, but
     56   * IMO let's leave it in for safety. */
     57  msg_type_id_t type;
     58  /** Untyped auxiliary data. You shouldn't have to mess with this
     59   * directly. */
     60  msg_aux_data_t aux_data__;
     61 } msg_t;
     62 
     63 /**
     64 * A function that a subscriber uses to receive a message.
     65 **/
     66 typedef void (*recv_fn_t)(const msg_t *m);
     67 
     68 /**
     69 * Table of functions to use for a given C type.  Any omitted (NULL) functions
     70 * will be treated as no-ops.
     71 **/
     72 typedef struct dispatch_typefns_t {
     73  /** Release storage held for the auxiliary data of this type. */
     74  void (*free_fn)(msg_aux_data_t);
     75  /** Format and return a newly allocated string describing the contents
     76   * of this data element. */
     77  char *(*fmt_fn)(msg_aux_data_t);
     78 } dispatch_typefns_t;
     79 
     80 #endif /* !defined(TOR_DISPATCH_MSGTYPES_H) */