[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 <assert.h>

#include "atomlist.h"
#include "frrcu.h"
#include "memory.h"
#include "hook.h"
#include "printfrr.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);

extern void zlog_msg_args(struct zlog_msg *msg, size_t *hdrlen,
			  size_t *n_argpos, const struct fmt_outpos **argpos);

/* 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);

/* Enable or disable 'immediate' output - default is to buffer messages. */
extern void zlog_set_immediate(bool set_p);

#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
6a0eb688 DL	28	#include <assert.h>
6a0eb688 DL	29
0bdeb5e5 DL	30	#include "atomlist.h"
	31	#include "frrcu.h"
	32	#include "memory.h"
	33	#include "hook.h"
e3daa82c	34	#include "printfrr.h"
0bdeb5e5	35
17e38209 RW	36	#ifdef __cplusplus
	37	extern "C" {
	38	#endif
	39
0bdeb5e5 DL	40	extern char zlog_prefix[];
	41	extern size_t zlog_prefixsz;
	42	extern int zlog_tmpdirfd;
	43
131879fb DL	44	struct xref_logmsg {
	45	struct xref xref;
	46
	47	const char *fmtstring;
	48	uint32_t priority;
	49	uint32_t ec;
2621bb8b	50	const char *args;
131879fb DL	51	};
	52
	53	struct xrefdata_logmsg {
	54	struct xrefdata xrefdata;
	55
	56	/* nothing more here right now */
	57	};
	58
0bdeb5e5 DL	59	/* These functions are set up to write to stdout/stderr without explicit
	60	* initialization and/or before config load. There is no need to call e.g.
	61	* fprintf(stderr, ...) just because it's "too early" at startup. Depending
	62	* on context, it may still be the right thing to use fprintf though -- try to
	63	* determine wether something is a log message or something else.
	64	*/
	65
131879fb DL	66	extern void vzlogx(const struct xref_logmsg *xref, int prio,
	67	const char *fmt, va_list ap);
	68	#define vzlog(prio, ...) vzlogx(NULL, prio, __VA_ARGS__)
0bdeb5e5	69
c2527ed2	70	PRINTFRR(2, 3)
0bdeb5e5 DL	71	static inline void zlog(int prio, const char *fmt, ...)
	72	{
	73	va_list ap;
	74
	75	va_start(ap, fmt);
	76	vzlog(prio, fmt, ap);
	77	va_end(ap);
	78	}
	79
131879fb DL	80	PRINTFRR(2, 3)
	81	static inline void zlog_ref(const struct xref_logmsg *xref,
	82	const char *fmt, ...)
	83	{
	84	va_list ap;
	85
	86	va_start(ap, fmt);
	87	vzlogx(xref, xref->priority, fmt, ap);
	88	va_end(ap);
	89	}
	90
c364a096 EDP	91	#define _zlog_ecref(ec_, prio, msg, ...) \
c364a096 EDP	92	do { \
131879fb	93	static struct xrefdata _xrefdata = { \
c364a096 EDP	94	.xref = NULL, \
c364a096 EDP	95	.uid = {}, \
131879fb	96	.hashstr = (msg), \
c364a096	97	.hashu32 = {(prio), (ec_)}, \
131879fb	98	}; \
c364a096 EDP	99	static const struct xref_logmsg _xref __attribute__( \
c364a096 EDP	100	(used)) = { \
131879fb DL	101	.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
	102	.fmtstring = (msg), \
	103	.priority = (prio), \
	104	.ec = (ec_), \
2621bb8b	105	.args = (#__VA_ARGS__), \
131879fb DL	106	}; \
131879fb DL	107	XREF_LINK(_xref.xref); \
a3c67498	108	zlog_ref(&_xref, (msg), ##__VA_ARGS__); \
131879fb DL	109	} while (0)
131879fb DL	110
a3c67498 DL	111	#define zlog_err(...) _zlog_ecref(0, LOG_ERR, __VA_ARGS__)
	112	#define zlog_warn(...) _zlog_ecref(0, LOG_WARNING, __VA_ARGS__)
	113	#define zlog_info(...) _zlog_ecref(0, LOG_INFO, __VA_ARGS__)
	114	#define zlog_notice(...) _zlog_ecref(0, LOG_NOTICE, __VA_ARGS__)
	115	#define zlog_debug(...) _zlog_ecref(0, LOG_DEBUG, __VA_ARGS__)
	116
131879fb DL	117	#define flog_err(ferr_id, format, ...) \
	118	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
	119	#define flog_warn(ferr_id, format, ...) \
	120	_zlog_ecref(ferr_id, LOG_WARNING, format, ## __VA_ARGS__)
	121
	122	#define flog_err_sys(ferr_id, format, ...) \
a3c67498	123	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
0bdeb5e5 DL	124
	125	extern void zlog_sigsafe(const char *text, size_t len);
	126
	127	/* extra priority value to disable a target without deleting it */
	128	#define ZLOG_DISABLED (LOG_EMERG-1)
	129
	130	/* zlog_msg encapsulates a particular logging call from somewhere in the code.
	131	* The same struct is passed around to all zlog_targets.
	132	*
	133	* This is used to defer formatting the log message until it is actually
	134	* requested by one of the targets. If none of the targets needs the message
	135	* formatted, the formatting call is avoided entirely.
	136	*
	137	* This struct is opaque / private to the core zlog code. Logging targets
	138	* should use zlog_msg_* functions to get text / timestamps / ... for a
	139	* message.
	140	*/
	141
	142	struct zlog_msg;
	143
	144	extern int zlog_msg_prio(struct zlog_msg *msg);
131879fb	145	extern const struct xref_logmsg zlog_msg_xref(struct zlog_msg msg);
0bdeb5e5 DL	146
	147	/* pass NULL as textlen if you don't need it. */
	148	extern const char zlog_msg_text(struct zlog_msg msg, size_t *textlen);
	149
e3daa82c DL	150	extern void zlog_msg_args(struct zlog_msg msg, size_t hdrlen,
	151	size_t n_argpos, const struct fmt_outpos *argpos);
	152
0bdeb5e5 DL	153	/* timestamp formatting control flags */
	154
	155	/* sub-second digit count */
	156	#define ZLOG_TS_PREC 0xfU
	157
	158	/* 8601: 0000-00-00T00:00:00Z (if used with ZLOG_TS_UTC)
	159	* 0000-00-00T00:00:00+00:00 (otherwise)
	160	* Legacy: 0000/00/00 00:00:00 (no TZ indicated!)
	161	*/
	162	#define ZLOG_TS_ISO8601 (1 << 8)
	163	#define ZLOG_TS_LEGACY (1 << 9)
	164
	165	/* default is local time zone */
	166	#define ZLOG_TS_UTC (1 << 10)
	167
	168	extern size_t zlog_msg_ts(struct zlog_msg msg, char out, size_t outsz,
	169	uint32_t flags);
	170
	171	/* This list & struct implements the actual logging targets. It is accessed
	172	* lock-free from all threads, and thus MUST only be changed atomically, i.e.
	173	* RCU.
	174	*
	175	* Since there's no atomic replace, the replacement action is an add followed
	176	* by a delete. This means that during logging config changes, log messages
	177	* may be duplicated in the log target that is being changed. The old entry
	178	* being changed MUST also at the very least not crash or do other stupid
	179	* things.
	180	*
	181	* This list and struct are NOT related to config. Logging config is kept
	182	* separately, and results in creating appropriate zlog_target(s) to realize
	183	* the config. Log targets may also be created from varying sources, e.g.
	184	* command line options, or VTY commands ("log monitor").
	185	*
	186	* struct zlog_target is intended to be embedded into a larger structure that
	187	* contains additional field for the specific logging target, e.g. an fd or
	188	* additional options. It MUST be the first field in that larger struct.
	189	*/
	190
960b9a53	191	PREDECL_ATOMLIST(zlog_targets);
0bdeb5e5 DL	192	struct zlog_target {
	193	struct zlog_targets_item head;
	194
	195	int prio_min;
	196
	197	void (logfn)(struct zlog_target zt, struct zlog_msg *msg[],
	198	size_t nmsgs);
	199
	200	/* for crash handlers, set to NULL if log target can't write crash logs
	201	* without possibly deadlocking (AS-Safe)
	202	*
	203	* text is not \0 terminated & split up into lines (e.g. no \n)
	204	*/
	205	void (logfn_sigsafe)(struct zlog_target zt, const char *text,
	206	size_t len);
	207
	208	struct rcu_head rcu_head;
	209	};
	210
	211	/* make a copy for RCUpdating. oldzt may be NULL to allocate a fresh one. */
	212	extern struct zlog_target zlog_target_clone(struct memtype mt,
	213	struct zlog_target *oldzt,
	214	size_t size);
	215
	216	/* update the zlog_targets list; both oldzt and newzt may be NULL. You
	217	* still need to zlog_target_free() the old target afterwards if it wasn't
	218	* NULL.
	219	*
	220	* Returns oldzt so you can zlog_target_free(zlog_target_replace(old, new));
	221	* (Some log targets may need extra cleanup inbetween, but remember the old
	222	* target MUST remain functional until the end of the current RCU cycle.)
	223	*/
	224	extern struct zlog_target zlog_target_replace(struct zlog_target oldzt,
	225	struct zlog_target *newzt);
	226
	227	/* Mostly for symmetry for zlog_target_clone(), just rcu_free() internally. */
	228	#define zlog_target_free(mt, zt) \
	229	rcu_free(mt, zt, rcu_head)
	230
	231	extern void zlog_init(const char progname, const char protoname,
	232	unsigned short instance, uid_t uid, gid_t gid);
	233	DECLARE_HOOK(zlog_init, (const char progname, const char protoname,
	234	unsigned short instance, uid_t uid, gid_t gid),
8451921b	235	(progname, protoname, instance, uid, gid));
0bdeb5e5 DL	236
0bdeb5e5 DL	237	extern void zlog_fini(void);
8451921b	238	DECLARE_KOOH(zlog_fini, (), ());
0bdeb5e5	239
a3c67498 DL	240	extern void zlog_set_prefix_ec(bool enable);
	241	extern bool zlog_get_prefix_ec(void);
	242	extern void zlog_set_prefix_xid(bool enable);
	243	extern bool zlog_get_prefix_xid(void);
	244
0bdeb5e5 DL	245	/* for tools & test programs, i.e. anything not a daemon.
	246	* (no cleanup needed at exit)
	247	*/
	248	extern void zlog_aux_init(const char *prefix, int prio_min);
	249	DECLARE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
8451921b	250	(prefix, prio_min));
0bdeb5e5 DL	251
	252	extern void zlog_startup_end(void);
	253
	254	extern void zlog_tls_buffer_init(void);
	255	extern void zlog_tls_buffer_flush(void);
	256	extern void zlog_tls_buffer_fini(void);
	257
42ddefe8 MS	258	/* Enable or disable 'immediate' output - default is to buffer messages. */
	259	extern void zlog_set_immediate(bool set_p);
	260
17e38209 RW	261	#ifdef __cplusplus
	262	}
	263	#endif
	264
0bdeb5e5	265	#endif /* _FRR_ZLOG_H */