Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1058 insertions, 0 deletions

diff --git a/lib/zlog.c b/lib/zlog.c
new file mode 100644
index 0000000..309a955
--- /dev/null
+++ b/lib/zlog.c
@@ -0,0 +1,1058 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2015-19  David Lamparter, for NetDEF, Inc.
+ */
+
+#include "zebra.h"
+
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <time.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+#include <pthread.h>
+
+/* gettid() & co. */
+#ifdef HAVE_PTHREAD_NP_H
+#include <pthread_np.h>
+#endif
+#ifdef linux
+#include <sys/syscall.h>
+#endif
+#ifdef __FreeBSD__
+#include <sys/thr.h>
+#endif
+#ifdef __NetBSD__
+#include <lwp.h>
+#endif
+#ifdef __DragonFly__
+#include <sys/lwp.h>
+#endif
+#ifdef __APPLE__
+#include <mach/mach_traps.h>
+#endif
+
+#ifdef HAVE_LIBUNWIND
+#define UNW_LOCAL_ONLY
+#include <libunwind.h>
+#include <dlfcn.h>
+#endif
+
+#include "memory.h"
+#include "atomlist.h"
+#include "printfrr.h"
+#include "frrcu.h"
+#include "zlog.h"
+#include "libfrr_trace.h"
+#include "frrevent.h"
+
+DEFINE_MTYPE_STATIC(LIB, LOG_MESSAGE,  "log message");
+DEFINE_MTYPE_STATIC(LIB, LOG_TLSBUF,   "log thread-local buffer");
+
+DEFINE_HOOK(zlog_init, (const char *progname, const char *protoname,
+			unsigned short instance, uid_t uid, gid_t gid),
+		       (progname, protoname, instance, uid, gid));
+DEFINE_KOOH(zlog_fini, (), ());
+DEFINE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
+			   (prefix, prio_min));
+
+char zlog_prefix[128];
+size_t zlog_prefixsz;
+int zlog_tmpdirfd = -1;
+int zlog_instance = -1;
+
+static atomic_bool zlog_ec = true, zlog_xid = true;
+
+/* these are kept around because logging is initialized (and directories
+ * & files created) before zprivs code switches to the FRR user;  therefore
+ * we need to chown() things so we don't get permission errors later when
+ * trying to delete things on shutdown
+ */
+static uid_t zlog_uid = -1;
+static gid_t zlog_gid = -1;
+
+DECLARE_ATOMLIST(zlog_targets, struct zlog_target, head);
+static struct zlog_targets_head zlog_targets;
+
+/* Global setting for buffered vs immediate output. The default is
+ * per-pthread buffering.
+ */
+static bool default_immediate;
+
+/* cf. zlog.h for additional comments on this struct.
+ *
+ * Note: you MUST NOT pass the format string + va_list to non-FRR format
+ * string functions (e.g. vsyslog, sd_journal_printv, ...) since FRR uses an
+ * extended prinf() with additional formats (%pI4 and the like).
+ *
+ * Also remember to use va_copy() on args.
+ */
+
+struct zlog_msg {
+	struct timespec ts;
+	int prio;
+
+	const char *fmt;
+	va_list args;
+	const struct xref_logmsg *xref;
+
+	char *stackbuf;
+	size_t stackbufsz;
+	char *text;
+	size_t textlen;
+	size_t hdrlen;
+
+	/* This is always ISO8601 with sub-second precision 9 here, it's
+	 * converted for callers as needed.  ts_dot points to the "."
+	 * separating sub-seconds.  ts_zonetail is "Z" or "+00:00" for the
+	 * local time offset.
+	 *
+	 * Valid if ZLOG_TS_ISO8601 is set.
+	 * (0 if timestamp has not been formatted yet)
+	 */
+	char ts_str[32], *ts_dot, ts_zonetail[8];
+	uint32_t ts_flags;
+
+	/* "mmm dd hh:mm:ss" for 3164 legacy syslog - too dissimilar from
+	 * the above, so just kept separately here.
+	 */
+	uint32_t ts_3164_flags;
+	char ts_3164_str[16];
+
+	/* at the time of writing, 16 args was the actual maximum of arguments
+	 * to a single zlog call.  Particularly printing flag bitmasks seems
+	 * to drive this.  That said, the overhead of dynamically sizing this
+	 * probably outweighs the value.  If anything, a printfrr extension
+	 * for printing flag bitmasks might be a good idea.
+	 */
+	struct fmt_outpos argpos[24];
+	size_t n_argpos;
+};
+
+/* thread-local log message buffering
+ *
+ * This is strictly optional and set up by calling zlog_tls_buffer_init()
+ * on a particular thread.
+ *
+ * If in use, this will create a temporary file in /var/tmp which is used as
+ * memory-mapped MAP_SHARED log message buffer.  The idea there is that buffer
+ * access doesn't require any syscalls, but in case of a crash the kernel
+ * knows to sync the memory back to disk.  This way the user can still get the
+ * last log messages if there were any left unwritten in the buffer.
+ *
+ * Sizing this dynamically isn't particularly useful, so here's an 8k buffer
+ * with a message limit of 64 messages.  Message metadata (e.g. priority,
+ * timestamp) aren't in the mmap region, so they're lost on crash, but we can
+ * live with that.
+ */
+
+#if defined(HAVE_OPENAT) && defined(HAVE_UNLINKAT)
+#define CAN_DO_TLS 1
+#endif
+
+#define TLS_LOG_BUF_SIZE	8192
+#define TLS_LOG_MAXMSG		64
+
+struct zlog_tls {
+	char *mmbuf;
+	size_t bufpos;
+	bool do_unlink;
+
+	size_t nmsgs;
+	struct zlog_msg msgs[TLS_LOG_MAXMSG];
+	struct zlog_msg *msgp[TLS_LOG_MAXMSG];
+};
+
+static inline void zlog_tls_free(void *arg);
+
+/* proper ELF TLS is a bit faster than pthread_[gs]etspecific, so if it's
+ * available we'll use it here
+ */
+
+#ifdef __OpenBSD__
+static pthread_key_t zlog_tls_key;
+
+static void zlog_tls_key_init(void) __attribute__((_CONSTRUCTOR(500)));
+static void zlog_tls_key_init(void)
+{
+	pthread_key_create(&zlog_tls_key, zlog_tls_free);
+}
+
+static void zlog_tls_key_fini(void) __attribute__((_DESTRUCTOR(500)));
+static void zlog_tls_key_fini(void)
+{
+	pthread_key_delete(zlog_tls_key);
+}
+
+static inline struct zlog_tls *zlog_tls_get(void)
+{
+	return pthread_getspecific(zlog_tls_key);
+}
+
+static inline void zlog_tls_set(struct zlog_tls *val)
+{
+	pthread_setspecific(zlog_tls_key, val);
+}
+#else
+# ifndef thread_local
+#  define thread_local __thread
+# endif
+
+static thread_local struct zlog_tls *zlog_tls_var
+	__attribute__((tls_model("initial-exec")));
+
+static inline struct zlog_tls *zlog_tls_get(void)
+{
+	return zlog_tls_var;
+}
+
+static inline void zlog_tls_set(struct zlog_tls *val)
+{
+	zlog_tls_var = val;
+}
+#endif
+
+#ifdef CAN_DO_TLS
+static intmax_t zlog_gettid(void)
+{
+#ifndef __OpenBSD__
+	/* accessing a TLS variable is much faster than a syscall */
+	static thread_local intmax_t cached_tid = -1;
+	if (cached_tid != -1)
+		return cached_tid;
+#endif
+
+	long rv = -1;
+#ifdef HAVE_PTHREAD_GETTHREADID_NP
+	rv = pthread_getthreadid_np();
+#elif defined(linux)
+	rv = syscall(__NR_gettid);
+#elif defined(__NetBSD__)
+	rv = _lwp_self();
+#elif defined(__FreeBSD__)
+	thr_self(&rv);
+#elif defined(__DragonFly__)
+	rv = lwp_gettid();
+#elif defined(__OpenBSD__)
+	rv = getthrid();
+#elif defined(__sun)
+	rv = pthread_self();
+#elif defined(__APPLE__)
+	rv = mach_thread_self();
+	mach_port_deallocate(mach_task_self(), rv);
+#endif
+
+#ifndef __OpenBSD__
+	cached_tid = rv;
+#endif
+	return rv;
+}
+
+void zlog_tls_buffer_init(void)
+{
+	struct zlog_tls *zlog_tls;
+	char mmpath[MAXPATHLEN];
+	int mmfd;
+	size_t i;
+
+	zlog_tls = zlog_tls_get();
+
+	if (zlog_tls || zlog_tmpdirfd < 0)
+		return;
+
+	zlog_tls = XCALLOC(MTYPE_LOG_TLSBUF, sizeof(*zlog_tls));
+	for (i = 0; i < array_size(zlog_tls->msgp); i++)
+		zlog_tls->msgp[i] = &zlog_tls->msgs[i];
+
+	snprintfrr(mmpath, sizeof(mmpath), "logbuf.%jd", zlog_gettid());
+
+	mmfd = openat(zlog_tmpdirfd, mmpath,
+		      O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC, 0600);
+	if (mmfd < 0) {
+		zlog_err("failed to open thread log buffer \"%s\": %s",
+			 mmpath, strerror(errno));
+		goto out_anon;
+	}
+	fchown(mmfd, zlog_uid, zlog_gid);
+
+#ifdef HAVE_POSIX_FALLOCATE
+	if (posix_fallocate(mmfd, 0, TLS_LOG_BUF_SIZE) != 0)
+	/* note next statement is under above if() */
+#endif
+	if (ftruncate(mmfd, TLS_LOG_BUF_SIZE) < 0) {
+		zlog_err("failed to allocate thread log buffer \"%s\": %s",
+			 mmpath, strerror(errno));
+		goto out_anon_unlink;
+	}
+
+	zlog_tls->mmbuf = mmap(NULL, TLS_LOG_BUF_SIZE, PROT_READ | PROT_WRITE,
+			      MAP_SHARED, mmfd, 0);
+	if (zlog_tls->mmbuf == MAP_FAILED) {
+		zlog_err("failed to mmap thread log buffer \"%s\": %s",
+			 mmpath, strerror(errno));
+		goto out_anon_unlink;
+	}
+	zlog_tls->do_unlink = true;
+
+	close(mmfd);
+	zlog_tls_set(zlog_tls);
+	return;
+
+out_anon_unlink:
+	unlinkat(zlog_tmpdirfd, mmpath, 0);
+	close(mmfd);
+out_anon:
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+	zlog_tls->mmbuf = mmap(NULL, TLS_LOG_BUF_SIZE, PROT_READ | PROT_WRITE,
+			      MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+
+	if (!zlog_tls->mmbuf) {
+		zlog_err("failed to anonymous-mmap thread log buffer: %s",
+			 strerror(errno));
+		XFREE(MTYPE_LOG_TLSBUF, zlog_tls);
+		zlog_tls_set(NULL);
+		return;
+	}
+
+	zlog_tls_set(zlog_tls);
+}
+
+void zlog_tls_buffer_fini(void)
+{
+	char mmpath[MAXPATHLEN];
+	struct zlog_tls *zlog_tls = zlog_tls_get();
+	bool do_unlink = zlog_tls ? zlog_tls->do_unlink : false;
+
+	zlog_tls_buffer_flush();
+
+	zlog_tls_free(zlog_tls);
+	zlog_tls_set(NULL);
+
+	snprintfrr(mmpath, sizeof(mmpath), "logbuf.%jd", zlog_gettid());
+	if (do_unlink && unlinkat(zlog_tmpdirfd, mmpath, 0))
+		zlog_err("unlink logbuf: %s (%d)", strerror(errno), errno);
+}
+
+#else /* !CAN_DO_TLS */
+void zlog_tls_buffer_init(void)
+{
+}
+
+void zlog_tls_buffer_fini(void)
+{
+}
+#endif
+
+void zlog_msg_pid(struct zlog_msg *msg, intmax_t *pid, intmax_t *tid)
+{
+#ifndef __OpenBSD__
+	static thread_local intmax_t cached_pid = -1;
+	if (cached_pid != -1)
+		*pid = cached_pid;
+	else
+		cached_pid = *pid = (intmax_t)getpid();
+#else
+	*pid = (intmax_t)getpid();
+#endif
+#ifdef CAN_DO_TLS
+	*tid = zlog_gettid();
+#else
+	*tid = *pid;
+#endif
+}
+
+static inline void zlog_tls_free(void *arg)
+{
+	struct zlog_tls *zlog_tls = arg;
+
+	if (!zlog_tls)
+		return;
+
+	munmap(zlog_tls->mmbuf, TLS_LOG_BUF_SIZE);
+	XFREE(MTYPE_LOG_TLSBUF, zlog_tls);
+}
+
+void zlog_tls_buffer_flush(void)
+{
+	struct zlog_target *zt;
+	struct zlog_tls *zlog_tls = zlog_tls_get();
+
+	if (!zlog_tls)
+		return;
+	if (!zlog_tls->nmsgs)
+		return;
+
+	rcu_read_lock();
+	frr_each_safe (zlog_targets, &zlog_targets, zt) {
+		if (!zt->logfn)
+			continue;
+
+		zt->logfn(zt, zlog_tls->msgp, zlog_tls->nmsgs);
+	}
+	rcu_read_unlock();
+
+	zlog_tls->bufpos = 0;
+	zlog_tls->nmsgs = 0;
+}
+
+
+static void vzlog_notls(const struct xref_logmsg *xref, int prio,
+			const char *fmt, va_list ap)
+{
+	struct zlog_target *zt;
+	struct zlog_msg stackmsg = {
+		.prio = prio & LOG_PRIMASK,
+		.fmt = fmt,
+		.xref = xref,
+	}, *msg = &stackmsg;
+	char stackbuf[512];
+
+	clock_gettime(CLOCK_REALTIME, &msg->ts);
+	va_copy(msg->args, ap);
+	msg->stackbuf = stackbuf;
+	msg->stackbufsz = sizeof(stackbuf);
+
+	rcu_read_lock();
+	frr_each_safe (zlog_targets, &zlog_targets, zt) {
+		if (prio > zt->prio_min)
+			continue;
+		if (!zt->logfn)
+			continue;
+
+		zt->logfn(zt, &msg, 1);
+	}
+	rcu_read_unlock();
+
+	va_end(msg->args);
+	if (msg->text && msg->text != stackbuf)
+		XFREE(MTYPE_LOG_MESSAGE, msg->text);
+}
+
+static void vzlog_tls(struct zlog_tls *zlog_tls, const struct xref_logmsg *xref,
+		      int prio, const char *fmt, va_list ap)
+{
+	struct zlog_target *zt;
+	struct zlog_msg *msg;
+	char *buf;
+	bool ignoremsg = true;
+	bool immediate = default_immediate;
+
+	/* avoid further processing cost if no target wants this message */
+	rcu_read_lock();
+	frr_each (zlog_targets, &zlog_targets, zt) {
+		if (prio > zt->prio_min)
+			continue;
+		ignoremsg = false;
+		break;
+	}
+	rcu_read_unlock();
+
+	if (ignoremsg)
+		return;
+
+	msg = &zlog_tls->msgs[zlog_tls->nmsgs];
+	zlog_tls->nmsgs++;
+	if (zlog_tls->nmsgs == array_size(zlog_tls->msgs))
+		immediate = true;
+
+	memset(msg, 0, sizeof(*msg));
+	clock_gettime(CLOCK_REALTIME, &msg->ts);
+	va_copy(msg->args, ap);
+	msg->stackbuf = buf = zlog_tls->mmbuf + zlog_tls->bufpos;
+	msg->stackbufsz = TLS_LOG_BUF_SIZE - zlog_tls->bufpos - 1;
+	msg->fmt = fmt;
+	msg->prio = prio & LOG_PRIMASK;
+	msg->xref = xref;
+	if (msg->prio < LOG_INFO)
+		immediate = true;
+
+	if (!immediate) {
+		/* messages written later need to take the formatting cost
+		 * immediately since we can't hold a reference on varargs
+		 */
+		zlog_msg_text(msg, NULL);
+
+		if (msg->text != buf)
+			/* zlog_msg_text called malloc() on us :( */
+			immediate = true;
+		else {
+			zlog_tls->bufpos += msg->textlen + 1;
+			/* write a second \0 to mark current end position
+			 * (in case of crash this signals end of unwritten log
+			 * messages in mmap'd logbuf file)
+			 */
+			zlog_tls->mmbuf[zlog_tls->bufpos] = '\0';
+
+			/* avoid malloc() for next message */
+			if (TLS_LOG_BUF_SIZE - zlog_tls->bufpos < 256)
+				immediate = true;
+		}
+	}
+
+	if (immediate)
+		zlog_tls_buffer_flush();
+
+	va_end(msg->args);
+	if (msg->text && msg->text != buf)
+		XFREE(MTYPE_LOG_MESSAGE, msg->text);
+}
+
+static void zlog_backtrace_msg(const struct xref_logmsg *xref, int prio)
+{
+	struct event *tc = pthread_getspecific(thread_current);
+	const char *uid = xref->xref.xrefdata->uid;
+	bool found_thread = false;
+
+	zlog(prio, "| (%s) message in thread %jd, at %s(), %s:%d", uid,
+	     zlog_gettid(), xref->xref.func, xref->xref.file, xref->xref.line);
+
+#ifdef HAVE_LIBUNWIND
+	const char *threadfunc = tc ? tc->xref->funcname : NULL;
+	bool found_caller = false;
+	unw_cursor_t cursor;
+	unw_context_t uc;
+	unw_word_t ip, off, sp;
+	Dl_info dlinfo;
+
+	unw_getcontext(&uc);
+
+	unw_init_local(&cursor, &uc);
+	while (unw_step(&cursor) > 0) {
+		char buf[96], name[128] = "?";
+		bool is_thread = false;
+
+		unw_get_reg(&cursor, UNW_REG_IP, &ip);
+		unw_get_reg(&cursor, UNW_REG_SP, &sp);
+
+		if (unw_is_signal_frame(&cursor))
+			zlog(prio, "| (%s)    ---- signal ----", uid);
+
+		if (!unw_get_proc_name(&cursor, buf, sizeof(buf), &off)) {
+			if (!strcmp(buf, xref->xref.func))
+				found_caller = true;
+			if (threadfunc && !strcmp(buf, threadfunc))
+				found_thread = is_thread = true;
+
+			snprintf(name, sizeof(name), "%s+%#lx", buf, (long)off);
+		}
+
+		if (!found_caller)
+			continue;
+
+		if (dladdr((void *)ip, &dlinfo))
+			zlog(prio, "| (%s) %-36s %16lx+%08lx %16lx %s", uid,
+			     name, (long)dlinfo.dli_fbase,
+			     (long)ip - (long)dlinfo.dli_fbase, (long)sp,
+			     dlinfo.dli_fname);
+		else
+			zlog(prio, "| (%s) %-36s %16lx %16lx", uid, name,
+			     (long)ip, (long)sp);
+
+		if (is_thread)
+			zlog(prio, "| (%s) ^- scheduled from %s(), %s:%u", uid,
+			     tc->xref->xref.func, tc->xref->xref.file,
+			     tc->xref->xref.line);
+	}
+#elif defined(HAVE_GLIBC_BACKTRACE)
+	void *frames[64];
+	char **names = NULL;
+	int n_frames, i;
+
+	n_frames = backtrace(frames, array_size(frames));
+	if (n_frames < 0)
+		n_frames = 0;
+	if (n_frames)
+		names = backtrace_symbols(frames, n_frames);
+
+	for (i = 0; i < n_frames; i++) {
+		void *retaddr = frames[i];
+		char *loc = names[i];
+
+		zlog(prio, "| (%s) %16lx %-36s", uid, (long)retaddr, loc);
+	}
+	free(names);
+#endif
+	if (!found_thread && tc)
+		zlog(prio, "| (%s) scheduled from %s(), %s:%u", uid,
+		     tc->xref->xref.func, tc->xref->xref.file,
+		     tc->xref->xref.line);
+}
+
+void vzlogx(const struct xref_logmsg *xref, int prio,
+	    const char *fmt, va_list ap)
+{
+	struct zlog_tls *zlog_tls = zlog_tls_get();
+
+#ifdef HAVE_LTTNG
+	va_list copy;
+	va_copy(copy, ap);
+	char *msg = vasprintfrr(MTYPE_LOG_MESSAGE, fmt, copy);
+
+	switch (prio) {
+	case LOG_ERR:
+		frrtracelog(TRACE_ERR, msg);
+		break;
+	case LOG_WARNING:
+		frrtracelog(TRACE_WARNING, msg);
+		break;
+	case LOG_DEBUG:
+		frrtracelog(TRACE_DEBUG, msg);
+		break;
+	case LOG_NOTICE:
+		frrtracelog(TRACE_DEBUG, msg);
+		break;
+	case LOG_INFO:
+	default:
+		frrtracelog(TRACE_INFO, msg);
+		break;
+	}
+
+	va_end(copy);
+	XFREE(MTYPE_LOG_MESSAGE, msg);
+#endif
+
+	if (zlog_tls)
+		vzlog_tls(zlog_tls, xref, prio, fmt, ap);
+	else
+		vzlog_notls(xref, prio, fmt, ap);
+
+	if (xref) {
+		struct xrefdata_logmsg *xrdl;
+
+		xrdl = container_of(xref->xref.xrefdata, struct xrefdata_logmsg,
+				    xrefdata);
+		if (xrdl->fl_print_bt)
+			zlog_backtrace_msg(xref, prio);
+	}
+}
+
+void zlog_sigsafe(const char *text, size_t len)
+{
+	struct zlog_target *zt;
+	const char *end = text + len, *nlpos;
+
+	while (text < end) {
+		nlpos = memchr(text, '\n', end - text);
+		if (!nlpos)
+			nlpos = end;
+
+		frr_each (zlog_targets, &zlog_targets, zt) {
+			if (LOG_CRIT > zt->prio_min)
+				continue;
+			if (!zt->logfn_sigsafe)
+				continue;
+
+			zt->logfn_sigsafe(zt, text, nlpos - text);
+		}
+
+		if (nlpos == end)
+			break;
+		text = nlpos + 1;
+	}
+}
+
+void _zlog_assert_failed(const struct xref_assert *xref, const char *extra, ...)
+{
+	va_list ap;
+	static bool assert_in_assert; /* "global-ish" variable, init to 0 */
+
+	if (assert_in_assert)
+		abort();
+	assert_in_assert = true;
+
+	if (extra) {
+		struct va_format vaf;
+
+		va_start(ap, extra);
+		vaf.fmt = extra;
+		vaf.va = &ap;
+
+		zlog(LOG_CRIT,
+		     "%s:%d: %s(): assertion (%s) failed, extra info: %pVA",
+		     xref->xref.file, xref->xref.line, xref->xref.func,
+		     xref->expr, &vaf);
+
+		va_end(ap);
+	} else
+		zlog(LOG_CRIT, "%s:%d: %s(): assertion (%s) failed",
+		     xref->xref.file, xref->xref.line, xref->xref.func,
+		     xref->expr);
+
+	/* abort() prints backtrace & memstats in SIGABRT handler */
+	abort();
+}
+
+int zlog_msg_prio(struct zlog_msg *msg)
+{
+	return msg->prio;
+}
+
+const struct xref_logmsg *zlog_msg_xref(struct zlog_msg *msg)
+{
+	return msg->xref;
+}
+
+const char *zlog_msg_text(struct zlog_msg *msg, size_t *textlen)
+{
+	if (!msg->text) {
+		va_list args;
+		bool do_xid, do_ec;
+		size_t need = 0, hdrlen;
+		struct fbuf fb = {
+			.buf = msg->stackbuf,
+			.pos = msg->stackbuf,
+			.len = msg->stackbufsz,
+		};
+
+		do_ec = atomic_load_explicit(&zlog_ec, memory_order_relaxed);
+		do_xid = atomic_load_explicit(&zlog_xid, memory_order_relaxed);
+
+		if (msg->xref && do_xid && msg->xref->xref.xrefdata->uid[0]) {
+			need += bputch(&fb, '[');
+			need += bputs(&fb, msg->xref->xref.xrefdata->uid);
+			need += bputch(&fb, ']');
+		}
+		if (msg->xref && do_ec && msg->xref->ec)
+			need += bprintfrr(&fb, "[EC %u]", msg->xref->ec);
+		if (need)
+			need += bputch(&fb, ' ');
+
+		msg->hdrlen = hdrlen = need;
+		assert(hdrlen < msg->stackbufsz);
+
+		fb.outpos = msg->argpos;
+		fb.outpos_n = array_size(msg->argpos);
+		fb.outpos_i = 0;
+
+		va_copy(args, msg->args);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+		/* format-string checking is done further up the chain */
+		need += vbprintfrr(&fb, msg->fmt, args);
+#pragma GCC diagnostic pop
+		va_end(args);
+
+		msg->textlen = need;
+		need += bputch(&fb, '\n');
+
+		if (need <= msg->stackbufsz)
+			msg->text = msg->stackbuf;
+		else {
+			msg->text = XMALLOC(MTYPE_LOG_MESSAGE, need);
+
+			memcpy(msg->text, msg->stackbuf, hdrlen);
+
+			fb.buf = msg->text;
+			fb.len = need;
+			fb.pos = msg->text + hdrlen;
+			fb.outpos_i = 0;
+
+			va_copy(args, msg->args);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wformat-nonliteral"
+			/* same as above */
+			vbprintfrr(&fb, msg->fmt, args);
+#pragma GCC diagnostic pop
+			va_end(args);
+
+			bputch(&fb, '\n');
+		}
+
+		msg->n_argpos = fb.outpos_i;
+	}
+	if (textlen)
+		*textlen = msg->textlen;
+	return msg->text;
+}
+
+void zlog_msg_args(struct zlog_msg *msg, size_t *hdrlen, size_t *n_argpos,
+		   const struct fmt_outpos **argpos)
+{
+	if (!msg->text)
+		zlog_msg_text(msg, NULL);
+
+	if (hdrlen)
+		*hdrlen = msg->hdrlen;
+	if (n_argpos)
+		*n_argpos = msg->n_argpos;
+	if (argpos)
+		*argpos = msg->argpos;
+}
+
+#define ZLOG_TS_FORMAT		(ZLOG_TS_ISO8601 | ZLOG_TS_LEGACY)
+#define ZLOG_TS_FLAGS		~ZLOG_TS_PREC
+
+size_t zlog_msg_ts(struct zlog_msg *msg, struct fbuf *out, uint32_t flags)
+{
+	size_t outsz = out ? (out->buf + out->len - out->pos) : 0;
+	size_t len1;
+
+	if (!(flags & ZLOG_TS_FORMAT))
+		return 0;
+
+	if (!(msg->ts_flags & ZLOG_TS_FORMAT) ||
+	    ((msg->ts_flags ^ flags) & ZLOG_TS_UTC)) {
+		struct tm tm;
+
+		if (flags & ZLOG_TS_UTC)
+			gmtime_r(&msg->ts.tv_sec, &tm);
+		else
+			localtime_r(&msg->ts.tv_sec, &tm);
+
+		strftime(msg->ts_str, sizeof(msg->ts_str),
+			 "%Y-%m-%dT%H:%M:%S", &tm);
+
+		if (flags & ZLOG_TS_UTC) {
+			msg->ts_zonetail[0] = 'Z';
+			msg->ts_zonetail[1] = '\0';
+		} else
+			snprintfrr(msg->ts_zonetail, sizeof(msg->ts_zonetail),
+				   "%+03d:%02d",
+				   (int)(tm.tm_gmtoff / 3600),
+				   (int)(labs(tm.tm_gmtoff) / 60) % 60);
+
+		msg->ts_dot = msg->ts_str + strlen(msg->ts_str);
+		snprintfrr(msg->ts_dot,
+			   msg->ts_str + sizeof(msg->ts_str) - msg->ts_dot,
+			   ".%09lu", (unsigned long)msg->ts.tv_nsec);
+
+		msg->ts_flags = ZLOG_TS_ISO8601 | (flags & ZLOG_TS_UTC);
+	}
+
+	len1 = flags & ZLOG_TS_PREC;
+	len1 = (msg->ts_dot - msg->ts_str) + (len1 ? len1 + 1 : 0);
+
+	if (len1 > strlen(msg->ts_str))
+		len1 = strlen(msg->ts_str);
+
+	if (flags & ZLOG_TS_LEGACY) {
+		if (!out)
+			return len1;
+
+		if (len1 > outsz) {
+			memset(out->pos, 0, outsz);
+			out->pos += outsz;
+			return len1;
+		}
+
+		/* just swap out the formatting, faster than redoing it */
+		for (char *p = msg->ts_str; p < msg->ts_str + len1; p++) {
+			switch (*p) {
+			case '-':
+				*out->pos++ = '/';
+				break;
+			case 'T':
+				*out->pos++ = ' ';
+				break;
+			default:
+				*out->pos++ = *p;
+			}
+		}
+		return len1;
+	} else {
+		size_t len2 = strlen(msg->ts_zonetail);
+
+		if (!out)
+			return len1 + len2;
+
+		if (len1 + len2 > outsz) {
+			memset(out->pos, 0, outsz);
+			out->pos += outsz;
+			return len1 + len2;
+		}
+
+		memcpy(out->pos, msg->ts_str, len1);
+		out->pos += len1;
+		memcpy(out->pos, msg->ts_zonetail, len2);
+		out->pos += len2;
+		return len1 + len2;
+	}
+}
+
+size_t zlog_msg_ts_3164(struct zlog_msg *msg, struct fbuf *out, uint32_t flags)
+{
+	flags &= ZLOG_TS_UTC;
+
+	if (!msg->ts_3164_str[0] || flags != msg->ts_3164_flags) {
+		/* these are "hardcoded" in RFC3164, so they're here too... */
+		static const char *const months[12] = {
+			"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+			"Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
+		};
+		struct tm tm;
+
+		/* RFC3164 explicitly asks for local time, but common usage
+		 * also includes UTC.
+		 */
+		if (flags & ZLOG_TS_UTC)
+			gmtime_r(&msg->ts.tv_sec, &tm);
+		else
+			localtime_r(&msg->ts.tv_sec, &tm);
+
+		snprintfrr(msg->ts_3164_str, sizeof(msg->ts_3164_str),
+			   "%3s %2d %02d:%02d:%02d", months[tm.tm_mon],
+			   tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
+
+		msg->ts_3164_flags = flags;
+	}
+	return bputs(out, msg->ts_3164_str);
+}
+
+void zlog_msg_tsraw(struct zlog_msg *msg, struct timespec *ts)
+{
+	memcpy(ts, &msg->ts, sizeof(*ts));
+}
+
+void zlog_set_prefix_ec(bool enable)
+{
+	atomic_store_explicit(&zlog_ec, enable, memory_order_relaxed);
+}
+
+bool zlog_get_prefix_ec(void)
+{
+	return atomic_load_explicit(&zlog_ec, memory_order_relaxed);
+}
+
+void zlog_set_prefix_xid(bool enable)
+{
+	atomic_store_explicit(&zlog_xid, enable, memory_order_relaxed);
+}
+
+bool zlog_get_prefix_xid(void)
+{
+	return atomic_load_explicit(&zlog_xid, memory_order_relaxed);
+}
+
+/* setup functions */
+
+struct zlog_target *zlog_target_clone(struct memtype *mt,
+				      struct zlog_target *oldzt, size_t size)
+{
+	struct zlog_target *newzt;
+
+	newzt = XCALLOC(mt, size);
+	if (oldzt) {
+		newzt->prio_min = oldzt->prio_min;
+		newzt->logfn = oldzt->logfn;
+		newzt->logfn_sigsafe = oldzt->logfn_sigsafe;
+	}
+
+	return newzt;
+}
+
+struct zlog_target *zlog_target_replace(struct zlog_target *oldzt,
+					struct zlog_target *newzt)
+{
+	if (newzt)
+		zlog_targets_add_tail(&zlog_targets, newzt);
+	if (oldzt)
+		zlog_targets_del(&zlog_targets, oldzt);
+	return oldzt;
+}
+
+/*
+ * Enable or disable 'immediate' output - default is to buffer
+ * each pthread's messages.
+ */
+void zlog_set_immediate(bool set_p)
+{
+	default_immediate = set_p;
+}
+
+/* common init */
+
+#define TMPBASEDIR "/var/tmp/frr"
+
+static char zlog_tmpdir[MAXPATHLEN];
+
+void zlog_aux_init(const char *prefix, int prio_min)
+{
+	if (prefix)
+		strlcpy(zlog_prefix, prefix, sizeof(zlog_prefix));
+
+	hook_call(zlog_aux_init, prefix, prio_min);
+}
+
+void zlog_init(const char *progname, const char *protoname,
+	       unsigned short instance, uid_t uid, gid_t gid)
+{
+	zlog_uid = uid;
+	zlog_gid = gid;
+	zlog_instance = instance;
+
+	if (instance) {
+		snprintfrr(zlog_tmpdir, sizeof(zlog_tmpdir), "%s/%s-%d.%ld",
+			   TMPBASEDIR, progname, instance, (long)getpid());
+
+		zlog_prefixsz = snprintfrr(zlog_prefix, sizeof(zlog_prefix),
+					   "%s[%d]: ", protoname, instance);
+	} else {
+		snprintfrr(zlog_tmpdir, sizeof(zlog_tmpdir), "%s/%s.%ld",
+			   TMPBASEDIR, progname, (long)getpid());
+
+		zlog_prefixsz = snprintfrr(zlog_prefix, sizeof(zlog_prefix),
+					   "%s: ", protoname);
+	}
+
+	if (mkdir(TMPBASEDIR, 0700) != 0) {
+		if (errno != EEXIST) {
+			zlog_err("failed to mkdir \"%s\": %s",
+				 TMPBASEDIR, strerror(errno));
+			goto out_warn;
+		}
+	}
+	chown(TMPBASEDIR, zlog_uid, zlog_gid);
+
+	if (mkdir(zlog_tmpdir, 0700) != 0) {
+		zlog_err("failed to mkdir \"%s\": %s",
+			 zlog_tmpdir, strerror(errno));
+		goto out_warn;
+	}
+
+#ifdef O_PATH
+	zlog_tmpdirfd = open(zlog_tmpdir,
+			     O_PATH | O_RDONLY | O_CLOEXEC);
+#else
+	zlog_tmpdirfd = open(zlog_tmpdir,
+			     O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+#endif
+	if (zlog_tmpdirfd < 0) {
+		zlog_err("failed to open \"%s\": %s",
+			 zlog_tmpdir, strerror(errno));
+		goto out_warn;
+	}
+
+#ifdef AT_EMPTY_PATH
+	fchownat(zlog_tmpdirfd, "", zlog_uid, zlog_gid, AT_EMPTY_PATH);
+#else
+	chown(zlog_tmpdir, zlog_uid, zlog_gid);
+#endif
+
+	hook_call(zlog_init, progname, protoname, instance, uid, gid);
+	return;
+
+out_warn:
+	zlog_err("crashlog and per-thread log buffering unavailable!");
+	hook_call(zlog_init, progname, protoname, instance, uid, gid);
+}
+
+void zlog_fini(void)
+{
+	hook_call(zlog_fini);
+
+	if (zlog_tmpdirfd >= 0) {
+		close(zlog_tmpdirfd);
+		zlog_tmpdirfd = -1;
+
+		if (rmdir(zlog_tmpdir))
+			zlog_err("failed to rmdir \"%s\": %s",
+				 zlog_tmpdir, strerror(errno));
+	}
+}