[mirror_frr.git] / lib / zlog.h

// SPDX-License-Identifier: ISC
/*
 * Copyright (c) 2015-19  David Lamparter, for NetDEF, Inc.
 */

#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

DECLARE_MGROUP(LOG);

extern char zlog_prefix[];
extern size_t zlog_prefixsz;
extern int zlog_tmpdirfd;
extern int zlog_instance;
extern const char *zlog_progname;

struct xref_logmsg {
	struct xref xref;

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

/* whether flag was added in config mode or enable mode */
#define LOGMSG_FLAG_EPHEMERAL	(1 << 0)
#define LOGMSG_FLAG_PERSISTENT	(1 << 1)

struct xrefdata_logmsg {
	struct xrefdata xrefdata;

	uint8_t fl_print_bt;
};

/* 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 whether something is a log message or something else.
 */

extern void vzlogx(const struct xref_logmsg *xref, int prio, const char *fmt,
		   va_list ap) PRINTFRR(3, 0);
#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_logmsg _xrefdata = {                    \
			.xrefdata =                                            \
				{                                              \
					.xref = NULL,                          \
					.uid = {},                             \
					.hashstr = (msg),                      \
					.hashu32 = {(prio), (ec_)},            \
				},                                             \
		};                                                             \
		static const struct xref_logmsg _xref __attribute__(           \
			(used)) = {                                            \
			.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata.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);

/* text is NOT \0 terminated; instead there is a \n after textlen since the
 * logging targets would jump extra hoops otherwise for a single byte.  (the
 * \n is not included in textlen)
 *
 * calling this with NULL textlen is likely wrong.
 * use  "%.*s", (int)textlen, text  when passing to printf-like functions
 */
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)

struct timespec;

extern size_t zlog_msg_ts(struct zlog_msg *msg, struct fbuf *out,
			  uint32_t flags);
extern void zlog_msg_tsraw(struct zlog_msg *msg, struct timespec *ts);

/* "mmm dd hh:mm:ss" for RFC3164 syslog.  Only ZLOG_TS_UTC for flags. */
extern size_t zlog_msg_ts_3164(struct zlog_msg *msg, struct fbuf *out,
			       uint32_t flags);

/* currently just returns the current PID/TID since we never write another
 * thread's messages
 */
extern void zlog_msg_pid(struct zlog_msg *msg, intmax_t *pid, intmax_t *tid);

/* 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);

extern const char *zlog_priority_str(int priority);

#ifdef __cplusplus
}
#endif

#endif /* _FRR_ZLOG_H */
Commit	Line	Data
acddc0ed	1	// SPDX-License-Identifier: ISC
0bdeb5e5 DL	2	/*
0bdeb5e5 DL	3	* Copyright (c) 2015-19 David Lamparter, for NetDEF, Inc.
0bdeb5e5 DL	4	*/
	5
	6	#ifndef _FRR_ZLOG_H
	7	#define _FRR_ZLOG_H
	8
	9	#include <stdarg.h>
	10	#include <stdbool.h>
	11	#include <stdint.h>
	12	#include <string.h>
	13	#include <syslog.h>
	14	#include <unistd.h>
	15	#include <sys/uio.h>
	16
6a0eb688 DL	17	#include <assert.h>
6a0eb688 DL	18
0bdeb5e5 DL	19	#include "atomlist.h"
	20	#include "frrcu.h"
	21	#include "memory.h"
	22	#include "hook.h"
e3daa82c	23	#include "printfrr.h"
0bdeb5e5	24
17e38209 RW	25	#ifdef __cplusplus
	26	extern "C" {
	27	#endif
	28
c6610ea9 DL	29	DECLARE_MGROUP(LOG);
c6610ea9 DL	30
0bdeb5e5 DL	31	extern char zlog_prefix[];
	32	extern size_t zlog_prefixsz;
	33	extern int zlog_tmpdirfd;
5c58f5d3	34	extern int zlog_instance;
c6610ea9	35	extern const char *zlog_progname;
0bdeb5e5	36
131879fb DL	37	struct xref_logmsg {
	38	struct xref xref;
	39
	40	const char *fmtstring;
	41	uint32_t priority;
	42	uint32_t ec;
2621bb8b	43	const char *args;
131879fb DL	44	};
131879fb DL	45
ef990bd9 DL	46	/* whether flag was added in config mode or enable mode */
	47	#define LOGMSG_FLAG_EPHEMERAL (1 << 0)
	48	#define LOGMSG_FLAG_PERSISTENT (1 << 1)
	49
131879fb DL	50	struct xrefdata_logmsg {
	51	struct xrefdata xrefdata;
	52
ef990bd9	53	uint8_t fl_print_bt;
131879fb DL	54	};
131879fb DL	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
f89c0aed	60	* determine whether something is a log message or something else.
0bdeb5e5 DL	61	*/
0bdeb5e5 DL	62
c695bdbe DL	63	extern void vzlogx(const struct xref_logmsg xref, int prio, const char fmt,
c695bdbe DL	64	va_list ap) PRINTFRR(3, 0);
131879fb	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 { \
ef990bd9 DL	90	static struct xrefdata_logmsg _xrefdata = { \
	91	.xrefdata = \
	92	{ \
	93	.xref = NULL, \
	94	.uid = {}, \
	95	.hashstr = (msg), \
	96	.hashu32 = {(prio), (ec_)}, \
	97	}, \
131879fb	98	}; \
c364a096 EDP	99	static const struct xref_logmsg _xref __attribute__( \
c364a096 EDP	100	(used)) = { \
ef990bd9 DL	101	.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata.xrefdata, \
ef990bd9 DL	102	__func__), \
131879fb DL	103	.fmtstring = (msg), \
	104	.priority = (prio), \
	105	.ec = (ec_), \
2621bb8b	106	.args = (#__VA_ARGS__), \
131879fb DL	107	}; \
131879fb DL	108	XREF_LINK(_xref.xref); \
a3c67498	109	zlog_ref(&_xref, (msg), ##__VA_ARGS__); \
131879fb DL	110	} while (0)
131879fb DL	111
a3c67498 DL	112	#define zlog_err(...) _zlog_ecref(0, LOG_ERR, __VA_ARGS__)
	113	#define zlog_warn(...) _zlog_ecref(0, LOG_WARNING, __VA_ARGS__)
	114	#define zlog_info(...) _zlog_ecref(0, LOG_INFO, __VA_ARGS__)
	115	#define zlog_notice(...) _zlog_ecref(0, LOG_NOTICE, __VA_ARGS__)
	116	#define zlog_debug(...) _zlog_ecref(0, LOG_DEBUG, __VA_ARGS__)
	117
131879fb DL	118	#define flog_err(ferr_id, format, ...) \
	119	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
	120	#define flog_warn(ferr_id, format, ...) \
	121	_zlog_ecref(ferr_id, LOG_WARNING, format, ## __VA_ARGS__)
	122
	123	#define flog_err_sys(ferr_id, format, ...) \
a3c67498	124	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
0bdeb5e5 DL	125
	126	extern void zlog_sigsafe(const char *text, size_t len);
	127
	128	/* extra priority value to disable a target without deleting it */
	129	#define ZLOG_DISABLED (LOG_EMERG-1)
	130
	131	/* zlog_msg encapsulates a particular logging call from somewhere in the code.
	132	* The same struct is passed around to all zlog_targets.
	133	*
	134	* This is used to defer formatting the log message until it is actually
	135	* requested by one of the targets. If none of the targets needs the message
	136	* formatted, the formatting call is avoided entirely.
	137	*
	138	* This struct is opaque / private to the core zlog code. Logging targets
	139	* should use zlog_msg_* functions to get text / timestamps / ... for a
	140	* message.
	141	*/
	142
	143	struct zlog_msg;
	144
	145	extern int zlog_msg_prio(struct zlog_msg *msg);
131879fb	146	extern const struct xref_logmsg zlog_msg_xref(struct zlog_msg msg);
0bdeb5e5	147
8b94cb43 DL	148	/* text is NOT \0 terminated; instead there is a \n after textlen since the
	149	* logging targets would jump extra hoops otherwise for a single byte. (the
	150	* \n is not included in textlen)
	151	*
	152	* calling this with NULL textlen is likely wrong.
	153	* use "%.*s", (int)textlen, text when passing to printf-like functions
	154	*/
0bdeb5e5 DL	155	extern const char zlog_msg_text(struct zlog_msg msg, size_t *textlen);
0bdeb5e5 DL	156
e3daa82c DL	157	extern void zlog_msg_args(struct zlog_msg msg, size_t hdrlen,
	158	size_t n_argpos, const struct fmt_outpos *argpos);
	159
0bdeb5e5 DL	160	/* timestamp formatting control flags */
	161
	162	/* sub-second digit count */
	163	#define ZLOG_TS_PREC 0xfU
	164
	165	/* 8601: 0000-00-00T00:00:00Z (if used with ZLOG_TS_UTC)
	166	* 0000-00-00T00:00:00+00:00 (otherwise)
	167	* Legacy: 0000/00/00 00:00:00 (no TZ indicated!)
	168	*/
	169	#define ZLOG_TS_ISO8601 (1 << 8)
	170	#define ZLOG_TS_LEGACY (1 << 9)
	171
	172	/* default is local time zone */
	173	#define ZLOG_TS_UTC (1 << 10)
	174
df45017f DL	175	struct timespec;
df45017f DL	176
f6caaa65	177	extern size_t zlog_msg_ts(struct zlog_msg msg, struct fbuf out,
0bdeb5e5	178	uint32_t flags);
df45017f	179	extern void zlog_msg_tsraw(struct zlog_msg msg, struct timespec ts);
0bdeb5e5	180
243ff228 DL	181	/* "mmm dd hh:mm:ss" for RFC3164 syslog. Only ZLOG_TS_UTC for flags. */
	182	extern size_t zlog_msg_ts_3164(struct zlog_msg msg, struct fbuf out,
	183	uint32_t flags);
	184
78598fd0 DL	185	/* currently just returns the current PID/TID since we never write another
	186	* thread's messages
	187	*/
	188	extern void zlog_msg_pid(struct zlog_msg msg, intmax_t pid, intmax_t *tid);
	189
0bdeb5e5 DL	190	/* This list & struct implements the actual logging targets. It is accessed
	191	* lock-free from all threads, and thus MUST only be changed atomically, i.e.
	192	* RCU.
	193	*
	194	* Since there's no atomic replace, the replacement action is an add followed
	195	* by a delete. This means that during logging config changes, log messages
	196	* may be duplicated in the log target that is being changed. The old entry
	197	* being changed MUST also at the very least not crash or do other stupid
	198	* things.
	199	*
	200	* This list and struct are NOT related to config. Logging config is kept
	201	* separately, and results in creating appropriate zlog_target(s) to realize
	202	* the config. Log targets may also be created from varying sources, e.g.
	203	* command line options, or VTY commands ("log monitor").
	204	*
	205	* struct zlog_target is intended to be embedded into a larger structure that
	206	* contains additional field for the specific logging target, e.g. an fd or
	207	* additional options. It MUST be the first field in that larger struct.
	208	*/
	209
960b9a53	210	PREDECL_ATOMLIST(zlog_targets);
0bdeb5e5 DL	211	struct zlog_target {
	212	struct zlog_targets_item head;
	213
	214	int prio_min;
	215
	216	void (logfn)(struct zlog_target zt, struct zlog_msg *msg[],
	217	size_t nmsgs);
	218
	219	/* for crash handlers, set to NULL if log target can't write crash logs
	220	* without possibly deadlocking (AS-Safe)
	221	*
	222	* text is not \0 terminated & split up into lines (e.g. no \n)
	223	*/
	224	void (logfn_sigsafe)(struct zlog_target zt, const char *text,
	225	size_t len);
	226
	227	struct rcu_head rcu_head;
	228	};
	229
	230	/* make a copy for RCUpdating. oldzt may be NULL to allocate a fresh one. */
	231	extern struct zlog_target zlog_target_clone(struct memtype mt,
	232	struct zlog_target *oldzt,
	233	size_t size);
	234
	235	/* update the zlog_targets list; both oldzt and newzt may be NULL. You
	236	* still need to zlog_target_free() the old target afterwards if it wasn't
	237	* NULL.
	238	*
	239	* Returns oldzt so you can zlog_target_free(zlog_target_replace(old, new));
	240	* (Some log targets may need extra cleanup inbetween, but remember the old
	241	* target MUST remain functional until the end of the current RCU cycle.)
	242	*/
	243	extern struct zlog_target zlog_target_replace(struct zlog_target oldzt,
	244	struct zlog_target *newzt);
	245
	246	/* Mostly for symmetry for zlog_target_clone(), just rcu_free() internally. */
	247	#define zlog_target_free(mt, zt) \
	248	rcu_free(mt, zt, rcu_head)
	249
	250	extern void zlog_init(const char progname, const char protoname,
	251	unsigned short instance, uid_t uid, gid_t gid);
	252	DECLARE_HOOK(zlog_init, (const char progname, const char protoname,
	253	unsigned short instance, uid_t uid, gid_t gid),
8451921b	254	(progname, protoname, instance, uid, gid));
0bdeb5e5 DL	255
0bdeb5e5 DL	256	extern void zlog_fini(void);
8451921b	257	DECLARE_KOOH(zlog_fini, (), ());
0bdeb5e5	258
a3c67498 DL	259	extern void zlog_set_prefix_ec(bool enable);
	260	extern bool zlog_get_prefix_ec(void);
	261	extern void zlog_set_prefix_xid(bool enable);
	262	extern bool zlog_get_prefix_xid(void);
	263
0bdeb5e5 DL	264	/* for tools & test programs, i.e. anything not a daemon.
	265	* (no cleanup needed at exit)
	266	*/
	267	extern void zlog_aux_init(const char *prefix, int prio_min);
	268	DECLARE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
8451921b	269	(prefix, prio_min));
0bdeb5e5 DL	270
	271	extern void zlog_startup_end(void);
	272
	273	extern void zlog_tls_buffer_init(void);
	274	extern void zlog_tls_buffer_flush(void);
	275	extern void zlog_tls_buffer_fini(void);
	276
42ddefe8 MS	277	/* Enable or disable 'immediate' output - default is to buffer messages. */
	278	extern void zlog_set_immediate(bool set_p);
	279
c6610ea9 DL	280	extern const char *zlog_priority_str(int priority);
c6610ea9 DL	281
17e38209 RW	282	#ifdef __cplusplus
	283	}
	284	#endif
	285
0bdeb5e5	286	#endif /* _FRR_ZLOG_H */