[mirror_frr.git] / lib / zlog.h

/*
 * Copyright (c) 2015-19  David Lamparter, for NetDEF, Inc.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _FRR_ZLOG_H
#define _FRR_ZLOG_H

#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/uio.h>

#include "atomlist.h"
#include "frrcu.h"
#include "memory.h"
#include "hook.h"

#ifdef __cplusplus
extern "C" {
#endif

extern char zlog_prefix[];
extern size_t zlog_prefixsz;
extern int zlog_tmpdirfd;

struct xref_logmsg {
	struct xref xref;

	const char *fmtstring;
	uint32_t priority;
	uint32_t ec;
	const char *args;
};

struct xrefdata_logmsg {
	struct xrefdata xrefdata;

	/* nothing more here right now */
};

/* These functions are set up to write to stdout/stderr without explicit
 * initialization and/or before config load.  There is no need to call e.g.
 * fprintf(stderr, ...) just because it's "too early" at startup.  Depending
 * on context, it may still be the right thing to use fprintf though -- try to
 * determine wether something is a log message or something else.
 */

extern void vzlogx(const struct xref_logmsg *xref, int prio,
		   const char *fmt, va_list ap);
#define vzlog(prio, ...) vzlogx(NULL, prio, __VA_ARGS__)

PRINTFRR(2, 3)
static inline void zlog(int prio, const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vzlog(prio, fmt, ap);
	va_end(ap);
}

PRINTFRR(2, 3)
static inline void zlog_ref(const struct xref_logmsg *xref,
			    const char *fmt, ...)
{
	va_list ap;

	va_start(ap, fmt);
	vzlogx(xref, xref->priority, fmt, ap);
	va_end(ap);
}

#define _zlog_ref(prio, msg, ...)                                              \
	do {                                                                   \
		static struct xrefdata _xrefdata = {                           \
			.xref = NULL,                                          \
			.uid = {},                                             \
			.hashstr = (msg),                                      \
			.hashu32 = {(prio), 0},                                \
		};                                                             \
		static const struct xref_logmsg _xref __attribute__(           \
			(used)) = {                                            \
			.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
			.fmtstring = (msg),                                    \
			.priority = (prio),                                    \
			.args = (#__VA_ARGS__),                                \
		};                                                             \
		XREF_LINK(_xref.xref);                                         \
		zlog_ref(&_xref, (msg), ##__VA_ARGS__);                        \
	} while (0)

#define zlog_err(...)    _zlog_ref(LOG_ERR, __VA_ARGS__)
#define zlog_warn(...)   _zlog_ref(LOG_WARNING, __VA_ARGS__)
#define zlog_info(...)   _zlog_ref(LOG_INFO, __VA_ARGS__)
#define zlog_notice(...) _zlog_ref(LOG_NOTICE, __VA_ARGS__)
#define zlog_debug(...)  _zlog_ref(LOG_DEBUG, __VA_ARGS__)

#define _zlog_ecref(ec_, prio, msg, ...)                                       \
	do {                                                                   \
		static struct xrefdata _xrefdata = {                           \
			.xref = NULL,                                          \
			.uid = {},                                             \
			.hashstr = (msg),                                      \
			.hashu32 = {(prio), (ec_)},                            \
		};                                                             \
		static const struct xref_logmsg _xref __attribute__(           \
			(used)) = {                                            \
			.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
			.fmtstring = (msg),                                    \
			.priority = (prio),                                    \
			.ec = (ec_),                                           \
			.args = (#__VA_ARGS__),                                \
		};                                                             \
		XREF_LINK(_xref.xref);                                         \
		zlog_ref(&_xref, "[EC %u] " msg, ec_, ##__VA_ARGS__);          \
	} while (0)

#define flog_err(ferr_id, format, ...)                                         \
	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
#define flog_warn(ferr_id, format, ...)                                        \
	_zlog_ecref(ferr_id, LOG_WARNING, format, ## __VA_ARGS__)

#define flog_err_sys(ferr_id, format, ...)                                     \
	flog_err(ferr_id, format, ##__VA_ARGS__)
#define flog(priority, ferr_id, format, ...)                                   \
	zlog(priority, "[EC %u] " format, ferr_id, ##__VA_ARGS__)

extern void zlog_sigsafe(const char *text, size_t len);

/* extra priority value to disable a target without deleting it */
#define ZLOG_DISABLED	(LOG_EMERG-1)

/* zlog_msg encapsulates a particular logging call from somewhere in the code.
 * The same struct is passed around to all zlog_targets.
 *
 * This is used to defer formatting the log message until it is actually
 * requested by one of the targets.  If none of the targets needs the message
 * formatted, the formatting call is avoided entirely.
 *
 * This struct is opaque / private to the core zlog code.  Logging targets
 * should use zlog_msg_* functions to get text / timestamps / ... for a
 * message.
 */

struct zlog_msg;

extern int zlog_msg_prio(struct zlog_msg *msg);
extern const struct xref_logmsg *zlog_msg_xref(struct zlog_msg *msg);

/* pass NULL as textlen if you don't need it. */
extern const char *zlog_msg_text(struct zlog_msg *msg, size_t *textlen);

/* timestamp formatting control flags */

/* sub-second digit count */
#define ZLOG_TS_PREC		0xfU

/* 8601:   0000-00-00T00:00:00Z      (if used with ZLOG_TS_UTC)
 *         0000-00-00T00:00:00+00:00 (otherwise)
 * Legacy: 0000/00/00 00:00:00       (no TZ indicated!)
 */
#define ZLOG_TS_ISO8601		(1 << 8)
#define ZLOG_TS_LEGACY		(1 << 9)

/* default is local time zone */
#define ZLOG_TS_UTC		(1 << 10)

extern size_t zlog_msg_ts(struct zlog_msg *msg, char *out, size_t outsz,
			  uint32_t flags);

/* This list & struct implements the actual logging targets.  It is accessed
 * lock-free from all threads, and thus MUST only be changed atomically, i.e.
 * RCU.
 *
 * Since there's no atomic replace, the replacement action is an add followed
 * by a delete.  This means that during logging config changes, log messages
 * may be duplicated in the log target that is being changed.  The old entry
 * being changed MUST also at the very least not crash or do other stupid
 * things.
 *
 * This list and struct are NOT related to config.  Logging config is kept
 * separately, and results in creating appropriate zlog_target(s) to realize
 * the config.  Log targets may also be created from varying sources, e.g.
 * command line options, or VTY commands ("log monitor").
 *
 * struct zlog_target is intended to be embedded into a larger structure that
 * contains additional field for the specific logging target, e.g. an fd or
 * additional options.  It MUST be the first field in that larger struct.
 */

PREDECL_ATOMLIST(zlog_targets)
struct zlog_target {
	struct zlog_targets_item head;

	int prio_min;

	void (*logfn)(struct zlog_target *zt, struct zlog_msg *msg[],
		      size_t nmsgs);

	/* for crash handlers, set to NULL if log target can't write crash logs
	 * without possibly deadlocking (AS-Safe)
	 *
	 * text is not \0 terminated & split up into lines (e.g. no \n)
	 */
	void (*logfn_sigsafe)(struct zlog_target *zt, const char *text,
			      size_t len);

	struct rcu_head rcu_head;
};

/* make a copy for RCUpdating.  oldzt may be NULL to allocate a fresh one. */
extern struct zlog_target *zlog_target_clone(struct memtype *mt,
					     struct zlog_target *oldzt,
					     size_t size);

/* update the zlog_targets list;  both oldzt and newzt may be NULL.  You
 * still need to zlog_target_free() the old target afterwards if it wasn't
 * NULL.
 *
 * Returns oldzt so you can zlog_target_free(zlog_target_replace(old, new));
 * (Some log targets may need extra cleanup inbetween, but remember the old
 * target MUST remain functional until the end of the current RCU cycle.)
 */
extern struct zlog_target *zlog_target_replace(struct zlog_target *oldzt,
					       struct zlog_target *newzt);

/* Mostly for symmetry for zlog_target_clone(), just rcu_free() internally. */
#define zlog_target_free(mt, zt) \
	rcu_free(mt, zt, rcu_head)

extern void zlog_init(const char *progname, const char *protoname,
		      unsigned short instance, uid_t uid, gid_t gid);
DECLARE_HOOK(zlog_init, (const char *progname, const char *protoname,
			 unsigned short instance, uid_t uid, gid_t gid),
			(progname, protoname, instance, uid, gid));

extern void zlog_fini(void);
DECLARE_KOOH(zlog_fini, (), ());

/* for tools & test programs, i.e. anything not a daemon.
 * (no cleanup needed at exit)
 */
extern void zlog_aux_init(const char *prefix, int prio_min);
DECLARE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
			    (prefix, prio_min));

extern void zlog_startup_end(void);

extern void zlog_tls_buffer_init(void);
extern void zlog_tls_buffer_flush(void);
extern void zlog_tls_buffer_fini(void);

#ifdef __cplusplus
}
#endif

#endif /* _FRR_ZLOG_H */
Commit	Line	Data
0bdeb5e5 DL	1	/*
	2	* Copyright (c) 2015-19 David Lamparter, for NetDEF, Inc.
	3	*
	4	* Permission to use, copy, modify, and distribute this software for any
	5	* purpose with or without fee is hereby granted, provided that the above
	6	* copyright notice and this permission notice appear in all copies.
	7	*
	8	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	9	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	10	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	11	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	12	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	13	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	14	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	15	*/
	16
	17	#ifndef _FRR_ZLOG_H
	18	#define _FRR_ZLOG_H
	19
	20	#include <stdarg.h>
	21	#include <stdbool.h>
	22	#include <stdint.h>
	23	#include <string.h>
	24	#include <syslog.h>
	25	#include <unistd.h>
	26	#include <sys/uio.h>
	27
	28	#include "atomlist.h"
	29	#include "frrcu.h"
	30	#include "memory.h"
	31	#include "hook.h"
	32
17e38209 RW	33	#ifdef __cplusplus
	34	extern "C" {
	35	#endif
	36
0bdeb5e5 DL	37	extern char zlog_prefix[];
	38	extern size_t zlog_prefixsz;
	39	extern int zlog_tmpdirfd;
	40
131879fb DL	41	struct xref_logmsg {
	42	struct xref xref;
	43
	44	const char *fmtstring;
	45	uint32_t priority;
	46	uint32_t ec;
2621bb8b	47	const char *args;
131879fb DL	48	};
	49
	50	struct xrefdata_logmsg {
	51	struct xrefdata xrefdata;
	52
	53	/* nothing more here right now */
	54	};
	55
0bdeb5e5 DL	56	/* These functions are set up to write to stdout/stderr without explicit
	57	* initialization and/or before config load. There is no need to call e.g.
	58	* fprintf(stderr, ...) just because it's "too early" at startup. Depending
	59	* on context, it may still be the right thing to use fprintf though -- try to
	60	* determine wether something is a log message or something else.
	61	*/
	62
131879fb DL	63	extern void vzlogx(const struct xref_logmsg *xref, int prio,
	64	const char *fmt, va_list ap);
	65	#define vzlog(prio, ...) vzlogx(NULL, prio, __VA_ARGS__)
0bdeb5e5	66
c2527ed2	67	PRINTFRR(2, 3)
0bdeb5e5 DL	68	static inline void zlog(int prio, const char *fmt, ...)
	69	{
	70	va_list ap;
	71
	72	va_start(ap, fmt);
	73	vzlog(prio, fmt, ap);
	74	va_end(ap);
	75	}
	76
131879fb DL	77	PRINTFRR(2, 3)
	78	static inline void zlog_ref(const struct xref_logmsg *xref,
	79	const char *fmt, ...)
	80	{
	81	va_list ap;
	82
	83	va_start(ap, fmt);
	84	vzlogx(xref, xref->priority, fmt, ap);
	85	va_end(ap);
	86	}
	87
c364a096 EDP	88	#define _zlog_ref(prio, msg, ...) \
c364a096 EDP	89	do { \
131879fb	90	static struct xrefdata _xrefdata = { \
c364a096 EDP	91	.xref = NULL, \
c364a096 EDP	92	.uid = {}, \
131879fb	93	.hashstr = (msg), \
c364a096	94	.hashu32 = {(prio), 0}, \
131879fb	95	}; \
c364a096 EDP	96	static const struct xref_logmsg _xref __attribute__( \
c364a096 EDP	97	(used)) = { \
131879fb DL	98	.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
	99	.fmtstring = (msg), \
	100	.priority = (prio), \
2621bb8b	101	.args = (#__VA_ARGS__), \
131879fb DL	102	}; \
131879fb DL	103	XREF_LINK(_xref.xref); \
c364a096	104	zlog_ref(&_xref, (msg), ##__VA_ARGS__); \
131879fb DL	105	} while (0)
	106
	107	#define zlog_err(...) _zlog_ref(LOG_ERR, __VA_ARGS__)
	108	#define zlog_warn(...) _zlog_ref(LOG_WARNING, __VA_ARGS__)
	109	#define zlog_info(...) _zlog_ref(LOG_INFO, __VA_ARGS__)
	110	#define zlog_notice(...) _zlog_ref(LOG_NOTICE, __VA_ARGS__)
	111	#define zlog_debug(...) _zlog_ref(LOG_DEBUG, __VA_ARGS__)
	112
c364a096 EDP	113	#define _zlog_ecref(ec_, prio, msg, ...) \
c364a096 EDP	114	do { \
131879fb	115	static struct xrefdata _xrefdata = { \
c364a096 EDP	116	.xref = NULL, \
c364a096 EDP	117	.uid = {}, \
131879fb	118	.hashstr = (msg), \
c364a096	119	.hashu32 = {(prio), (ec_)}, \
131879fb	120	}; \
c364a096 EDP	121	static const struct xref_logmsg _xref __attribute__( \
c364a096 EDP	122	(used)) = { \
131879fb DL	123	.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
	124	.fmtstring = (msg), \
	125	.priority = (prio), \
	126	.ec = (ec_), \
2621bb8b	127	.args = (#__VA_ARGS__), \
131879fb DL	128	}; \
131879fb DL	129	XREF_LINK(_xref.xref); \
c364a096	130	zlog_ref(&_xref, "[EC %u] " msg, ec_, ##__VA_ARGS__); \
131879fb DL	131	} while (0)
	132
	133	#define flog_err(ferr_id, format, ...) \
	134	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
	135	#define flog_warn(ferr_id, format, ...) \
	136	_zlog_ecref(ferr_id, LOG_WARNING, format, ## __VA_ARGS__)
	137
	138	#define flog_err_sys(ferr_id, format, ...) \
	139	flog_err(ferr_id, format, ##__VA_ARGS__)
	140	#define flog(priority, ferr_id, format, ...) \
	141	zlog(priority, "[EC %u] " format, ferr_id, ##__VA_ARGS__)
0bdeb5e5 DL	142
	143	extern void zlog_sigsafe(const char *text, size_t len);
	144
	145	/* extra priority value to disable a target without deleting it */
	146	#define ZLOG_DISABLED (LOG_EMERG-1)
	147
	148	/* zlog_msg encapsulates a particular logging call from somewhere in the code.
	149	* The same struct is passed around to all zlog_targets.
	150	*
	151	* This is used to defer formatting the log message until it is actually
	152	* requested by one of the targets. If none of the targets needs the message
	153	* formatted, the formatting call is avoided entirely.
	154	*
	155	* This struct is opaque / private to the core zlog code. Logging targets
	156	* should use zlog_msg_* functions to get text / timestamps / ... for a
	157	* message.
	158	*/
	159
	160	struct zlog_msg;
	161
	162	extern int zlog_msg_prio(struct zlog_msg *msg);
131879fb	163	extern const struct xref_logmsg zlog_msg_xref(struct zlog_msg msg);
0bdeb5e5 DL	164
	165	/* pass NULL as textlen if you don't need it. */
	166	extern const char zlog_msg_text(struct zlog_msg msg, size_t *textlen);
	167
	168	/* timestamp formatting control flags */
	169
	170	/* sub-second digit count */
	171	#define ZLOG_TS_PREC 0xfU
	172
	173	/* 8601: 0000-00-00T00:00:00Z (if used with ZLOG_TS_UTC)
	174	* 0000-00-00T00:00:00+00:00 (otherwise)
	175	* Legacy: 0000/00/00 00:00:00 (no TZ indicated!)
	176	*/
	177	#define ZLOG_TS_ISO8601 (1 << 8)
	178	#define ZLOG_TS_LEGACY (1 << 9)
	179
	180	/* default is local time zone */
	181	#define ZLOG_TS_UTC (1 << 10)
	182
	183	extern size_t zlog_msg_ts(struct zlog_msg msg, char out, size_t outsz,
	184	uint32_t flags);
	185
	186	/* This list & struct implements the actual logging targets. It is accessed
	187	* lock-free from all threads, and thus MUST only be changed atomically, i.e.
	188	* RCU.
	189	*
	190	* Since there's no atomic replace, the replacement action is an add followed
	191	* by a delete. This means that during logging config changes, log messages
	192	* may be duplicated in the log target that is being changed. The old entry
	193	* being changed MUST also at the very least not crash or do other stupid
	194	* things.
	195	*
	196	* This list and struct are NOT related to config. Logging config is kept
	197	* separately, and results in creating appropriate zlog_target(s) to realize
	198	* the config. Log targets may also be created from varying sources, e.g.
	199	* command line options, or VTY commands ("log monitor").
	200	*
	201	* struct zlog_target is intended to be embedded into a larger structure that
	202	* contains additional field for the specific logging target, e.g. an fd or
	203	* additional options. It MUST be the first field in that larger struct.
	204	*/
	205
	206	PREDECL_ATOMLIST(zlog_targets)
	207	struct zlog_target {
	208	struct zlog_targets_item head;
	209
	210	int prio_min;
	211
	212	void (logfn)(struct zlog_target zt, struct zlog_msg *msg[],
	213	size_t nmsgs);
	214
	215	/* for crash handlers, set to NULL if log target can't write crash logs
	216	* without possibly deadlocking (AS-Safe)
	217	*
	218	* text is not \0 terminated & split up into lines (e.g. no \n)
	219	*/
	220	void (logfn_sigsafe)(struct zlog_target zt, const char *text,
	221	size_t len);
	222
	223	struct rcu_head rcu_head;
	224	};
	225
	226	/* make a copy for RCUpdating. oldzt may be NULL to allocate a fresh one. */
	227	extern struct zlog_target zlog_target_clone(struct memtype mt,
228	struct zlog_target *oldzt,
229	size_t size);
230
231	/* update the zlog_targets list; both oldzt and newzt may be NULL. You
232	* still need to zlog_target_free() the old target afterwards if it wasn't
233	* NULL.
234	*
235	* Returns oldzt so you can zlog_target_free(zlog_target_replace(old, new));
236	* (Some log targets may need extra cleanup inbetween, but remember the old
237	* target MUST remain functional until the end of the current RCU cycle.)
238	*/
239	extern struct zlog_target zlog_target_replace(struct zlog_target oldzt,
240	struct zlog_target *newzt);
241
242	/* Mostly for symmetry for zlog_target_clone(), just rcu_free() internally. */
243	#define zlog_target_free(mt, zt) \
244	rcu_free(mt, zt, rcu_head)
245
246	extern void zlog_init(const char progname, const char protoname,
247	unsigned short instance, uid_t uid, gid_t gid);
248	DECLARE_HOOK(zlog_init, (const char progname, const char protoname,
249	unsigned short instance, uid_t uid, gid_t gid),
8451921b	250	(progname, protoname, instance, uid, gid));
0bdeb5e5 DL	251
0bdeb5e5 DL	252	extern void zlog_fini(void);
8451921b	253	DECLARE_KOOH(zlog_fini, (), ());
0bdeb5e5 DL	254
	255	/* for tools & test programs, i.e. anything not a daemon.
	256	* (no cleanup needed at exit)
	257	*/
	258	extern void zlog_aux_init(const char *prefix, int prio_min);
	259	DECLARE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
8451921b	260	(prefix, prio_min));
0bdeb5e5 DL	261
	262	extern void zlog_startup_end(void);
	263
	264	extern void zlog_tls_buffer_init(void);
	265	extern void zlog_tls_buffer_flush(void);
	266	extern void zlog_tls_buffer_fini(void);
	267
17e38209 RW	268	#ifdef __cplusplus
	269	}
	270	#endif
	271
0bdeb5e5	272	#endif /* _FRR_ZLOG_H */