summaryrefslogtreecommitdiff
path: root/src/charon/bus/bus.h
blob: 4b46c7e82dd5b423f20436d0a6e2894398a17046 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
/**
 * @file bus.h
 *
 * @brief Interface of bus_t.
 *
 */

/*
 * Copyright (C) 2006 Martin Willi
 * Hochschule fuer Technik Rapperswil
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 */

#ifndef BUS_H_
#define BUS_H_

typedef enum signal_t signal_t;
typedef enum level_t level_t;
typedef struct bus_listener_t bus_listener_t;
typedef struct bus_t bus_t;

#include <stdarg.h>

#include <sa/ike_sa.h>
#include <sa/child_sa.h>


/**
 * @brief signals emitted by the daemon.
 *
 * Signaling is for different purporses. First, it allows debugging via
 * "debugging signal messages", sencondly, it allows to follow certain
 * mechanisms currently going on in the daemon. As we are multithreaded, 
 * and of multiple transactions are involved, it's not possible to follow
 * one connection setup without further infrastructure. These infrastructure
 * is provided by the bus and the signals the daemon emits to the bus.
 *
 * There are different scenarios to follow these signals, but all have
 * the same scheme. First, a START signal is emitted to indicate the daemon
 * has started to 
 *
 * @ingroup bus
 */
enum signal_t {
	/** pseudo signal, representing any other signal */
	SIG_ANY,
	
	/** debugging message from daemon main loop */
	DBG_DMN,
	/** debugging message from IKE_SA_MANAGER */
	DBG_MGR,
	/** debugging message from an IKE_SA */
	DBG_IKE,
	/** debugging message from a CHILD_SA */
	DBG_CHD,
	/** debugging message from job processing */
	DBG_JOB,
	/** debugging message from configuration backends */
	DBG_CFG,
	/** debugging message from kernel interface */
	DBG_KNL,
	/** debugging message from networking */
	DBG_NET,
	/** debugging message from message encoding/decoding */
	DBG_ENC,
	/** debugging message from libstrongswan via logging hook */
	DBG_LIB,
	
	/** number of debug signals */
	DBG_MAX,
	
	/** signals for IKE_SA establishment */
	IKE_UP_START,
	IKE_UP_SUCCESS,
	IKE_UP_FAILED,
	
	/** signals for IKE_SA delete */
	IKE_DOWN_START,
	IKE_DOWN_SUCCESS,
	IKE_DOWN_FAILED,
	
	/** signals for IKE_SA rekeying */
	IKE_REKEY_START,
	IKE_REKEY_SUCCESS,
	IKE_REKEY_FAILED,
	
	/** signals for CHILD_SA establishment */
	CHILD_UP_START,
	CHILD_UP_SUCCESS,
	CHILD_UP_FAILED,
	
	/** signals for CHILD_SA delete */
	CHILD_DOWN_START,
	CHILD_DOWN_SUCCESS,
	CHILD_DOWN_FAILED,
	
	/** signals for CHILD_SA rekeying */
	CHILD_REKEY_START,
	CHILD_REKEY_SUCCESS,
	CHILD_REKEY_FAILED,
	
	/** signals for CHILD_SA routing */
	CHILD_ROUTE_START,
	CHILD_ROUTE_SUCCESS,
	CHILD_ROUTE_FAILED,
	
	/** signals for CHILD_SA routing */
	CHILD_UNROUTE_START,
	CHILD_UNROUTE_SUCCESS,
	CHILD_UNROUTE_FAILED,
	
	SIG_MAX
};

/**
 * short names of signals using 3 chars
 */
extern enum_name_t *signal_names;

/**
 * Signal levels used to control output verbosity.
 */
enum level_t {
	/** numerical levels from 0 to 4 */
	LEVEL_0 = 0,
	LEVEL_1 = 1,
	LEVEL_2 = 2,
	LEVEL_3 = 3,
	LEVEL_4 = 4,
	/** absolutely silent, no signal is emitted with this level */
	LEVEL_SILENT = -1,
	/** alias for numberical levels */
	LEVEL_AUDIT = LEVEL_0,
	LEVEL_CTRL = LEVEL_1,
	LEVEL_CTRLMORE = LEVEL_2,
	LEVEL_RAW = LEVEL_3,
	LEVEL_PRIVATE = LEVEL_4,
};

#ifndef DEBUG_LEVEL
# define DEBUG_LEVEL 4
#endif /* DEBUG_LEVEL */

#if DEBUG_LEVEL >= 1
/**
 * @brief Log a debug message via the signal bus.
 *
 * @param signal	signal_t signal description
 * @param format	printf() style format string
 * @param ...		printf() style agument list
 */
# define DBG1(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_1, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL */
#if DEBUG_LEVEL >= 2
#define DBG2(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_2, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL */
#if DEBUG_LEVEL >= 3
#define DBG3(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_3, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL */
#if DEBUG_LEVEL >= 4
#define DBG4(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_4, format, ##__VA_ARGS__)
#endif /* DEBUG_LEVEL */

#ifndef DBG1
# define DBG1(...) {}
#endif /* DBG1 */
#ifndef DBG2
# define DBG2(...) {}
#endif /* DBG2 */
#ifndef DBG3
# define DBG3(...) {}
#endif /* DBG3 */
#ifndef DBG4
# define DBG4(...) {}
#endif /* DBG4 */

/**
 * @brief Raise a signal for an occured event.
 *
 * @param sig		signal_t signal description
 * @param format	printf() style format string
 * @param ...		printf() style agument list
 */
#define SIG(sig, format, ...) charon->bus->signal(charon->bus, sig, LEVEL_0, format, ##__VA_ARGS__)

/**
 * @brief Get the type of a signal.
 *
 * A signal may be a debugging signal with a specific context. They have
 * a level specific for their context > 0. All audit signals use the
 * type 0. This allows filtering of singals by their type.
 *
 * @param signal	signal to get the type from
 * @return			type of the signal, between 0..(DBG_MAX-1)
 */
#define SIG_TYPE(sig) (sig > DBG_MAX ? SIG_ANY : sig)


/**
 * @brief Interface for registering at the signal bus.
 *
 * To receive signals from the bus, the client implementing the
 * bus_listener_t interface registers itself at the signal bus.
 *
 * @ingroup bus
 */
struct bus_listener_t {
	
	/**
	 * @brief Send a signal to a bus listener.
	 *
	 * A numerical identification for the thread is included, as the
	 * associated IKE_SA, if any. Signal specifies the type of
	 * the event occured. The format string specifies
	 * an additional informational or error message with a printf() like
	 * variable argument list. This is in the va_list form, as forwarding
	 * a "..." parameters to functions is not (cleanly) possible.
	 * The implementing signal function returns TRUE to stay registered
	 * to the bus, or FALSE to unregister itself.
	 *
	 * @param this		listener
	 * @param singal	kind of the signal (up, down, rekeyed, ...)
	 * @param level		verbosity level of the signal
	 * @param thread	ID of the thread raised this signal
	 * @param ike_sa	IKE_SA associated to the event
	 * @param format	printf() style format string
	 * @param args		vprintf() style va_list argument list
	 " @return			TRUE to stay registered, FALSE to unregister
	 */
	bool (*signal) (bus_listener_t *this, signal_t signal, level_t level,
					int thread, ike_sa_t *ike_sa, char* format, va_list args);
};

/**
 * @brief Signal bus which sends signals to registered listeners.
 *
 * The signal bus is not much more than a multiplexer. A listener interested
 * in receiving event signals registers at the bus. Any signals sent to
 * are delivered to all registered listeners.
 * To deliver signals to threads, the blocking listen() call may be used
 * to wait for a signal.
 *
 * @ingroup bus
 */
struct bus_t {
	
	/**
	 * @brief Register a listener to the bus.
	 *
	 * A registered listener receives all signals which are sent to the bus.
	 * The listener is passive; the thread which emitted the signal
	 * processes the listener routine.
	 *
	 * @param this		bus
	 * @param listener	listener to register.
	 */
	void (*add_listener) (bus_t *this, bus_listener_t *listener);
	
	/**
	 * @brief Unregister a listener from the bus.
	 *
	 * @param this		bus
	 * @param listener	listener to unregister.
	 */
	void (*remove_listener) (bus_t *this, bus_listener_t *listener);
	
	/**
	 * @brief Listen actively on the bus.
	 *
	 * As we are fully multithreaded, we must provide a mechanism
	 * for active threads to listen to the bus. With the listen() method,
	 * a thread waits until a signal occurs, and then processes it.
	 * To prevent the listen() calling thread to miss signals emitted while
	 * it processes a signal, registration is required. This is done through
	 * the set_listen_state() method, see below.
	 *
	 * The listen() function is (has) a thread cancellation point, so might
	 * want to register cleanup handlers.
	 *
	 * @param this		bus
	 * @param level		verbosity level of the signal
	 * @param thread	receives thread number emitted the signal
	 * @param ike_sa	receives the IKE_SA involved in the signal, or NULL
	 * @param format	receives the format string supplied with the signal
	 * @param va_list	receives the variable argument list for format
	 * @return			the emitted signal type
	 */
	signal_t (*listen) (bus_t *this, level_t* level, int *thread,
						ike_sa_t **ike_sa, char** format, va_list* args);
	
	/**
	 * @brief Set the listening state of the calling thread.
	 *
	 * To prevent message loss for active listeners using listen(), threads
	 * must register themself to the bus before starting to listen(). When
	 * a signal occurs, the emitter waits until all threads with listen_state
	 * TRUE are waiting in the listen() method to process the signal.
	 * It is important that a thread with liste_state TRUE calls listen()
	 * periodically, or sets it's listening state to FALSE; otherwise
	 * all signal emitting threads get blocked on the bus.
	 *
	 * @param this		bus
	 * @param active	TRUE to set to listening
	 */
	void (*set_listen_state) (bus_t *this, bool active);
	
	/**
	 * @brief Set the IKE_SA the calling thread is using.
	 *
	 * To associate an received signal to an IKE_SA without passing it as
	 * parameter each time, the thread registers it's used IKE_SA each
	 * time it checked it out. Before checking it in, the thread unregisters
	 * the IKE_SA (by passing NULL). This IKE_SA is stored per-thread, so each
	 * thread has one IKE_SA registered (or not).
	 * 
	 * @param this		bus
	 * @param ike_sa	ike_sa to register, or NULL to unregister
	 */
	void (*set_sa) (bus_t *this, ike_sa_t *ike_sa);
	
	/**
	 * @brief Send a signal to the bus.
	 *
	 * The signal specifies the type of the event occured. The format string
	 * specifies an additional informational or error message with a
	 * printf() like variable argument list.
	 * Some useful macros are available to shorten this call.
	 * @see SIG(), DBG1()
	 *
	 * @param this		bus
	 * @param singal	kind of the signal (up, down, rekeyed, ...)
	 * @param level		verbosity level of the signal
	 * @param format	printf() style format string
	 * @param ...		printf() style argument list
	 */
	void (*signal) (bus_t *this, signal_t signal, level_t level, char* format, ...);
	
	/**
	 * @brief Send a signal to the bus using va_list arguments.
	 *
	 * Same as bus_t.signal(), but uses va_list argument list.
	 *
	 * @param this		bus
	 * @param singal	kind of the signal (up, down, rekeyed, ...)
	 * @param level		verbosity level of the signal
	 * @param format	printf() style format string
	 * @param args		va_list arguments
	 */
	void (*vsignal) (bus_t *this, signal_t signal, level_t level, char* format, va_list args);
	
	/**
	 * @brief Destroy the signal bus.
	 *
	 * @param this		bus to destroy
	 */
	void (*destroy) (bus_t *this);
};

/**
 * @brief Create the signal bus which multiplexes signals to its listeners.
 *
 * @return		signal bus instance
 * 
 * @ingroup bus
 */
bus_t *bus_create();

#endif /* BUS_H_ */