[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_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, (msg), ##__VA_ARGS__);                        \
	} while (0)

#define zlog_err(...)    _zlog_ecref(0, LOG_ERR, __VA_ARGS__)
#define zlog_warn(...)   _zlog_ecref(0, LOG_WARNING, __VA_ARGS__)
#define zlog_info(...)   _zlog_ecref(0, LOG_INFO, __VA_ARGS__)
#define zlog_notice(...) _zlog_ecref(0, LOG_NOTICE, __VA_ARGS__)
#define zlog_debug(...)  _zlog_ecref(0, LOG_DEBUG, __VA_ARGS__)

#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, ...)                                     \
	_zlog_ecref(ferr_id, LOG_ERR, format, ## __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, (), ());

extern void zlog_set_prefix_ec(bool enable);
extern bool zlog_get_prefix_ec(void);
extern void zlog_set_prefix_xid(bool enable);
extern bool zlog_get_prefix_xid(void);

/* 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_ecref(ec_, 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), (ec_)}, \
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), \
	101	.ec = (ec_), \
2621bb8b	102	.args = (#__VA_ARGS__), \
131879fb DL	103	}; \
131879fb DL	104	XREF_LINK(_xref.xref); \
a3c67498	105	zlog_ref(&_xref, (msg), ##__VA_ARGS__); \
131879fb DL	106	} while (0)
131879fb DL	107
a3c67498 DL	108	#define zlog_err(...) _zlog_ecref(0, LOG_ERR, __VA_ARGS__)
	109	#define zlog_warn(...) _zlog_ecref(0, LOG_WARNING, __VA_ARGS__)
	110	#define zlog_info(...) _zlog_ecref(0, LOG_INFO, __VA_ARGS__)
	111	#define zlog_notice(...) _zlog_ecref(0, LOG_NOTICE, __VA_ARGS__)
	112	#define zlog_debug(...) _zlog_ecref(0, LOG_DEBUG, __VA_ARGS__)
	113
131879fb DL	114	#define flog_err(ferr_id, format, ...) \
	115	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
	116	#define flog_warn(ferr_id, format, ...) \
	117	_zlog_ecref(ferr_id, LOG_WARNING, format, ## __VA_ARGS__)
	118
	119	#define flog_err_sys(ferr_id, format, ...) \
a3c67498	120	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
0bdeb5e5 DL	121
	122	extern void zlog_sigsafe(const char *text, size_t len);
	123
	124	/* extra priority value to disable a target without deleting it */
	125	#define ZLOG_DISABLED (LOG_EMERG-1)
	126
	127	/* zlog_msg encapsulates a particular logging call from somewhere in the code.
	128	* The same struct is passed around to all zlog_targets.
	129	*
	130	* This is used to defer formatting the log message until it is actually
	131	* requested by one of the targets. If none of the targets needs the message
	132	* formatted, the formatting call is avoided entirely.
	133	*
	134	* This struct is opaque / private to the core zlog code. Logging targets
	135	* should use zlog_msg_* functions to get text / timestamps / ... for a
	136	* message.
	137	*/
	138
	139	struct zlog_msg;
	140
	141	extern int zlog_msg_prio(struct zlog_msg *msg);
131879fb	142	extern const struct xref_logmsg zlog_msg_xref(struct zlog_msg msg);
0bdeb5e5 DL	143
	144	/* pass NULL as textlen if you don't need it. */
	145	extern const char zlog_msg_text(struct zlog_msg msg, size_t *textlen);
	146
	147	/* timestamp formatting control flags */
	148
	149	/* sub-second digit count */
	150	#define ZLOG_TS_PREC 0xfU
	151
	152	/* 8601: 0000-00-00T00:00:00Z (if used with ZLOG_TS_UTC)
	153	* 0000-00-00T00:00:00+00:00 (otherwise)
	154	* Legacy: 0000/00/00 00:00:00 (no TZ indicated!)
	155	*/
	156	#define ZLOG_TS_ISO8601 (1 << 8)
	157	#define ZLOG_TS_LEGACY (1 << 9)
	158
	159	/* default is local time zone */
	160	#define ZLOG_TS_UTC (1 << 10)
	161
	162	extern size_t zlog_msg_ts(struct zlog_msg msg, char out, size_t outsz,
	163	uint32_t flags);
	164
	165	/* This list & struct implements the actual logging targets. It is accessed
	166	* lock-free from all threads, and thus MUST only be changed atomically, i.e.
	167	* RCU.
	168	*
	169	* Since there's no atomic replace, the replacement action is an add followed
	170	* by a delete. This means that during logging config changes, log messages
	171	* may be duplicated in the log target that is being changed. The old entry
	172	* being changed MUST also at the very least not crash or do other stupid
	173	* things.
	174	*
	175	* This list and struct are NOT related to config. Logging config is kept
	176	* separately, and results in creating appropriate zlog_target(s) to realize
	177	* the config. Log targets may also be created from varying sources, e.g.
	178	* command line options, or VTY commands ("log monitor").
	179	*
	180	* struct zlog_target is intended to be embedded into a larger structure that
	181	* contains additional field for the specific logging target, e.g. an fd or
	182	* additional options. It MUST be the first field in that larger struct.
	183	*/
	184
960b9a53	185	PREDECL_ATOMLIST(zlog_targets);
0bdeb5e5 DL	186	struct zlog_target {
	187	struct zlog_targets_item head;
	188
	189	int prio_min;
	190
	191	void (logfn)(struct zlog_target zt, struct zlog_msg *msg[],
	192	size_t nmsgs);
	193
	194	/* for crash handlers, set to NULL if log target can't write crash logs
	195	* without possibly deadlocking (AS-Safe)
	196	*
	197	* text is not \0 terminated & split up into lines (e.g. no \n)
	198	*/
	199	void (logfn_sigsafe)(struct zlog_target zt, const char *text,
	200	size_t len);
	201
	202	struct rcu_head rcu_head;
	203	};
	204
	205	/* make a copy for RCUpdating. oldzt may be NULL to allocate a fresh one. */
	206	extern struct zlog_target zlog_target_clone(struct memtype mt,
	207	struct zlog_target *oldzt,
	208	size_t size);
	209
	210	/* update the zlog_targets list; both oldzt and newzt may be NULL. You
	211	* still need to zlog_target_free() the old target afterwards if it wasn't
	212	* NULL.
	213	*
	214	* Returns oldzt so you can zlog_target_free(zlog_target_replace(old, new));
	215	* (Some log targets may need extra cleanup inbetween, but remember the old
	216	* target MUST remain functional until the end of the current RCU cycle.)
	217	*/
	218	extern struct zlog_target zlog_target_replace(struct zlog_target oldzt,
	219	struct zlog_target *newzt);
	220
	221	/* Mostly for symmetry for zlog_target_clone(), just rcu_free() internally. */
	222	#define zlog_target_free(mt, zt) \
	223	rcu_free(mt, zt, rcu_head)
	224
	225	extern void zlog_init(const char progname, const char protoname,
	226	unsigned short instance, uid_t uid, gid_t gid);
	227	DECLARE_HOOK(zlog_init, (const char progname, const char protoname,
	228	unsigned short instance, uid_t uid, gid_t gid),
8451921b	229	(progname, protoname, instance, uid, gid));
0bdeb5e5 DL	230
0bdeb5e5 DL	231	extern void zlog_fini(void);
8451921b	232	DECLARE_KOOH(zlog_fini, (), ());
0bdeb5e5	233
a3c67498 DL	234	extern void zlog_set_prefix_ec(bool enable);
	235	extern bool zlog_get_prefix_ec(void);
	236	extern void zlog_set_prefix_xid(bool enable);
	237	extern bool zlog_get_prefix_xid(void);
	238
0bdeb5e5 DL	239	/* for tools & test programs, i.e. anything not a daemon.
	240	* (no cleanup needed at exit)
	241	*/
	242	extern void zlog_aux_init(const char *prefix, int prio_min);
	243	DECLARE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
8451921b	244	(prefix, prio_min));
0bdeb5e5 DL	245
	246	extern void zlog_startup_end(void);
	247
	248	extern void zlog_tls_buffer_init(void);
	249	extern void zlog_tls_buffer_flush(void);
	250	extern void zlog_tls_buffer_fini(void);
	251
17e38209 RW	252	#ifdef __cplusplus
	253	}
	254	#endif
	255
0bdeb5e5	256	#endif /* _FRR_ZLOG_H */