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Diffstat (limited to 'src/lib/dispatch/msgtypes.h')
-rw-r--r-- | src/lib/dispatch/msgtypes.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/lib/dispatch/msgtypes.h b/src/lib/dispatch/msgtypes.h new file mode 100644 index 0000000000..01d969dcb5 --- /dev/null +++ b/src/lib/dispatch/msgtypes.h @@ -0,0 +1,80 @@ +/* Copyright (c) 2001, Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file msgtypes.h + * \brief Types used for messages in the dispatcher code. + **/ + +#ifndef TOR_DISPATCH_MSGTYPES_H +#define TOR_DISPATCH_MSGTYPES_H + +#include <stdint.h> + +#include "ext/tor_queue.h" + +/** + * These types are aliases for subsystems, channels, and message IDs. + **/ +typedef uint16_t subsys_id_t; +typedef uint16_t channel_id_t; +typedef uint16_t message_id_t; + +/** + * This identifies a C type that can be sent along with a message. + **/ +typedef uint16_t msg_type_id_t; + +/** + * An ID value returned for *_type_t when none exists. + */ +#define ERROR_ID 65535 + +/** + * Auxiliary (untyped) data sent along with a message. + * + * We define this as a union of a pointer and a u64, so that the integer + * types will have the same range across platforms. + **/ +typedef union { + void *ptr; + uint64_t u64; +} msg_aux_data_t; + +/** + * Structure of a received message. + **/ +typedef struct msg_t { + TOR_SIMPLEQ_ENTRY(msg_t) next; + subsys_id_t sender; + channel_id_t channel; + message_id_t msg; + /** We could omit this field, since it is implicit in the message type, but + * IMO let's leave it in for safety. */ + msg_type_id_t type; + /** Untyped auxiliary data. You shouldn't have to mess with this + * directly. */ + msg_aux_data_t aux_data__; +} msg_t; + +/** + * A function that a subscriber uses to receive a message. + **/ +typedef void (*recv_fn_t)(const msg_t *m); + +/** + * Table of functions to use for a given C type. Any omitted (NULL) functions + * will be treated as no-ops. + **/ +typedef struct dispatch_typefns_t { + /** Release storage held for the auxiliary data of this type. */ + void (*free_fn)(msg_aux_data_t); + /** Format and return a newly allocated string describing the contents + * of this data element. */ + char *(*fmt_fn)(msg_aux_data_t); +} dispatch_typefns_t; + +#endif /* !defined(TOR_DISPATCH_MSGTYPES_H) */ |