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Diffstat (limited to 'lib/zlog.h')
| -rw-r--r-- | lib/zlog.h | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/lib/zlog.h b/lib/zlog.h new file mode 100644 index 0000000..a207b29 --- /dev/null +++ b/lib/zlog.h @@ -0,0 +1,286 @@ +// 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 */ |