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bird/sysdep/unix/log.c

474 lines
9.9 KiB
C

/*
* BIRD Library -- Logging Functions
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Logging
*
* The Logging module offers a simple set of functions for writing
* messages to system logs and to the debug output. Message classes
* used by this module are described in |birdlib.h| and also in the
* user's manual.
*/
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include "nest/bird.h"
#include "nest/cli.h"
#include "conf/conf.h"
#include "lib/string.h"
#include "lib/lists.h"
#include "sysdep/unix/unix.h"
static struct rfile *dbg_rf;
static list *current_log_list;
static char *current_syslog_name; /* NULL -> syslog closed */
_Atomic uint max_thread_id = ATOMIC_VAR_INIT(1);
_Thread_local uint this_thread_id;
#include <pthread.h>
static pthread_mutex_t log_mutex;
static inline void log_lock(void) { pthread_mutex_lock(&log_mutex); }
static inline void log_unlock(void) { pthread_mutex_unlock(&log_mutex); }
/* Logging flags to validly prepare logging messages */
#define LOGGING_TO_TERMINAL 0x1
#define LOGGING_TO_FILE 0x2
static _Atomic uint logging_flags;
#ifdef HAVE_SYSLOG_H
#include <sys/syslog.h>
static int syslog_priorities[] = {
LOG_DEBUG,
LOG_DEBUG,
LOG_DEBUG,
LOG_INFO,
LOG_ERR,
LOG_WARNING,
LOG_ERR,
LOG_ERR,
LOG_CRIT,
LOG_CRIT
};
#endif
static char *class_names[] = {
"???",
"DBG",
"TRACE",
"INFO",
"RMT",
"WARN",
"ERR",
"AUTH",
"FATAL",
"BUG"
};
static inline off_t
log_size(struct log_config *l)
{
struct stat st;
return (!fstat(rf_fileno(l->rf), &st) && S_ISREG(st.st_mode)) ? st.st_size : 0;
}
static void
log_close(struct log_config *l)
{
if (l->rf != &rf_stderr)
rfree(l->rf);
l->rf = NULL;
}
static int
log_open(struct log_config *l)
{
l->rf = rf_open(config->pool, l->filename, RF_APPEND);
if (!l->rf)
{
/* Well, we cannot do much in case of error as log is closed */
l->mask = 0;
return -1;
}
l->pos = log_size(l);
return 0;
}
static int
log_rotate(struct log_config *l)
{
log_close(l);
/* If we cannot rename the logfile, we at least try to delete it
in order to continue logging and not exceeding logfile size */
if ((rename(l->filename, l->backup) < 0) &&
(unlink(l->filename) < 0))
{
l->mask = 0;
return -1;
}
return log_open(l);
}
#define LOG_MSG_OFFSET (TM_DATETIME_BUFFER_SIZE + 64)
/**
* log_commit - commit a log message
* @class: message class information (%L_DEBUG to %L_BUG, see |lib/birdlib.h|)
* @buf: message to write
*
* This function writes a message prepared in the log buffer to the
* log file (as specified in the configuration). The log buffer is
* reset after that. The log message is a full line, log_commit()
* terminates it.
*
* The message class is an integer, not a first char of a string like
* in log(), so it should be written like *L_INFO.
*/
void
log_commit(log_buffer *buf)
{
struct log_config *l;
if (buf->buf.pos == buf->buf.end)
#define TOO_LONG " ... <too long>"
memcpy(buf->buf.end - sizeof TOO_LONG, TOO_LONG, sizeof TOO_LONG);
#undef TOO_LONG
log_lock();
WALK_LIST(l, *current_log_list)
{
if (!(l->mask & (1 << buf->class)))
continue;
if (l->rf && buf->tm_pos)
{
*buf->buf.pos = '\n';
byte *begin = l->terminal_flag ? buf->buf.start : buf->tm_pos;
off_t msg_len = buf->buf.pos - begin + 1;
if (l->limit && (l->pos + msg_len > l->limit) && (log_rotate(l) < 0))
continue;
l->pos += msg_len;
while ((write(rf_fileno(l->rf), buf->tm_pos, msg_len) < 0) && (errno == EINTR))
;
}
#ifdef HAVE_SYSLOG_H
else
{
*buf->buf.pos = '\0';
syslog(syslog_priorities[buf->class], "%s", buf->msg_pos);
}
#endif
}
log_unlock();
buf->msg_pos = buf->tm_pos = NULL;
}
int buffer_vprint(buffer *buf, const char *fmt, va_list args);
void
log_prepare(log_buffer *buf, int class)
{
buf->buf.start = buf->buf.pos = buf->block;
buf->buf.end = buf->block + sizeof buf->block;
int lf = atomic_load_explicit(&logging_flags, memory_order_acquire);
if (lf & LOGGING_TO_TERMINAL)
buffer_puts(&buf->buf, "bird: ");
if (lf & LOGGING_TO_FILE)
{
const char *fmt = config ? config->tf_log.fmt1 : "%F %T.%3f";
buf->tm_pos = buf->buf.pos;
int t = tm_format_real_time(buf->buf.pos, buf->buf.end - buf->buf.pos, fmt, current_real_time());
if (t)
buf->buf.pos += t;
else
buffer_puts(&buf->buf, "<time format error>");
buffer_print(&buf->buf, " [%04x] <%s> ", THIS_THREAD_ID, class_names[class]);
}
buf->msg_pos = buf->buf.pos;
buf->class = class;
}
static void
vlog(int class, const char *msg, va_list args)
{
static _Thread_local log_buffer buf;
log_prepare(&buf, class);
buffer_vprint(&buf.buf, msg, args);
log_commit(&buf);
}
/**
* log - log a message
* @msg: printf-like formatting string with message class information
* prepended (%L_DEBUG to %L_BUG, see |lib/birdlib.h|)
*
* This function formats a message according to the format string @msg
* and writes it to the corresponding log file (as specified in the
* configuration). Please note that the message is automatically
* formatted as a full line, no need to include |\n| inside.
* It is essentially a sequence of log_reset(), logn() and log_commit().
*/
void
log_msg(const char *msg, ...)
{
int class = 1;
va_list args;
va_start(args, msg);
if (*msg >= 1 && *msg <= 8)
class = *msg++;
vlog(class, msg, args);
va_end(args);
}
void
log_rl(struct tbf *f, const char *msg, ...)
{
int class = 1;
va_list args;
/* Rate limiting is a bit tricky here as it also logs '...' during the first hit */
if (tbf_limit(f) && (f->drop > 1))
return;
if (*msg >= 1 && *msg <= 8)
class = *msg++;
va_start(args, msg);
vlog(class, (f->drop ? "..." : msg), args);
va_end(args);
}
/**
* bug - report an internal error
* @msg: a printf-like error message
*
* This function logs an internal error and aborts execution
* of the program.
*/
void
bug(const char *msg, ...)
{
va_list args;
va_start(args, msg);
vlog(L_BUG[0], msg, args);
va_end(args);
abort();
}
/**
* bug - report a fatal error
* @msg: a printf-like error message
*
* This function logs a fatal error and aborts execution
* of the program.
*/
void
die(const char *msg, ...)
{
va_list args;
va_start(args, msg);
vlog(L_FATAL[0], msg, args);
va_end(args);
exit(1);
}
static struct timespec dbg_time_start;
/**
* debug - write to debug output
* @msg: a printf-like message
*
* This function formats the message @msg and prints it out
* to the debugging output. No newline character is appended.
*/
void
debug(const char *msg, ...)
{
#define MAX_DEBUG_BUFSIZE 16384
va_list args;
char buf[MAX_DEBUG_BUFSIZE], *pos = buf;
int max = MAX_DEBUG_BUFSIZE;
va_start(args, msg);
if (dbg_rf)
{
int s = bvsnprintf(pos, max, msg, args);
if (s < 0)
bug("Extremely long debug output, split it.");
write(rf_fileno(dbg_rf), buf, s);
}
va_end(args);
}
/**
* debug_safe - async-safe write to debug output
* @msg: a string message
*
* This function prints the message @msg to the debugging output in a
* way that is async safe and can be used in signal handlers. No newline
* character is appended.
*/
void
debug_safe(const char *msg)
{
if (dbg_rf)
write(rf_fileno(dbg_rf), msg, strlen(msg));
}
static list *
default_log_list(int initial, const char **syslog_name)
{
static list log_list;
init_list(&log_list);
*syslog_name = NULL;
#ifdef HAVE_SYSLOG_H
if (!dbg_rf)
{
static struct log_config lc_syslog;
lc_syslog = (struct log_config){
.mask = ~0
};
add_tail(&log_list, &lc_syslog.n);
*syslog_name = bird_name;
}
#endif
if (dbg_rf && (dbg_rf != &rf_stderr))
{
static struct log_config lc_debug;
lc_debug = (struct log_config){
.mask = ~0,
.rf = dbg_rf,
};
add_tail(&log_list, &lc_debug.n);
}
if (initial || (dbg_rf == &rf_stderr))
{
static struct log_config lc_stderr;
lc_stderr = (struct log_config){
.mask = ~0,
.terminal_flag = 1,
.rf = &rf_stderr,
};
add_tail(&log_list, &lc_stderr.n);
}
return &log_list;
}
void
log_switch(int initial, list *logs, const char *new_syslog_name)
{
struct log_config *l;
/* We should not manipulate with log list when other threads may use it */
log_lock();
if (!logs || EMPTY_LIST(*logs))
logs = default_log_list(initial, &new_syslog_name);
/* Close the logs to avoid pinning them on disk when deleted */
if (current_log_list)
WALK_LIST(l, *current_log_list)
if (l->rf)
log_close(l);
/* Reopen the logs, needed for 'configure undo' */
uint flags = 0;
if (logs)
WALK_LIST(l, *logs)
{
if (l->terminal_flag)
flags |= LOGGING_TO_TERMINAL;
if (l->filename && !l->rf)
log_open(l);
if (l->rf)
flags |= LOGGING_TO_FILE;
}
atomic_store_explicit(&logging_flags, flags, memory_order_release);
current_log_list = logs;
#ifdef HAVE_SYSLOG_H
if (!bstrcmp(current_syslog_name, new_syslog_name))
goto done;
if (current_syslog_name)
{
closelog();
xfree(current_syslog_name);
current_syslog_name = NULL;
}
if (new_syslog_name)
{
current_syslog_name = xstrdup(new_syslog_name);
openlog(current_syslog_name, LOG_CONS | LOG_NDELAY, LOG_DAEMON);
}
#endif
done:
/* Logs exchange done, let the threads log as before */
log_unlock();
}
void
log_init_debug(char *f)
{
clock_gettime(CLOCK_MONOTONIC, &dbg_time_start);
if (dbg_rf && dbg_rf != &rf_stderr)
close(rf_fileno(dbg_rf));
if (!f)
dbg_rf = NULL;
else if (!*f)
dbg_rf = &rf_stderr;
else if (!(dbg_rf = rf_open(&root_pool, f, RF_APPEND)))
{
/* Cannot use die() nor log() here, logging is not yet initialized */
fprintf(stderr, "bird: Unable to open debug file %s: %s\n", f, strerror(errno));
exit(1);
}
}