NetBSD/lib/libc/gen/syslog.c

346 lines
8.6 KiB
C

/* $NetBSD: syslog.c,v 1.28 2002/05/26 14:03:20 wiz Exp $ */
/*
* Copyright (c) 1983, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)syslog.c 8.5 (Berkeley) 4/29/95";
#else
__RCSID("$NetBSD: syslog.c,v 1.28 2002/05/26 14:03:20 wiz Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "reentrant.h"
#ifdef __weak_alias
__weak_alias(closelog,_closelog)
__weak_alias(openlog,_openlog)
__weak_alias(setlogmask,_setlogmask)
__weak_alias(syslog,_syslog)
__weak_alias(vsyslog,_vsyslog)
#endif
static int LogFile = -1; /* fd for log */
static int connected; /* have done connect */
static int LogStat = 0; /* status bits, set by openlog() */
static const char *LogTag = NULL; /* string to tag the entry with */
static int LogFacility = LOG_USER; /* default facility code */
static int LogMask = 0xff; /* mask of priorities to be logged */
static void openlog_unlocked __P((const char *, int, int));
static void closelog_unlocked __P((void));
#ifdef _REENT
static mutex_t syslog_mutex = MUTEX_INITIALIZER;
#endif
#ifdef lint
static const int ZERO = 0;
#else
#define ZERO 0
#endif
/*
* syslog, vsyslog --
* print message on log file; output is intended for syslogd(8).
*/
void
syslog(int pri, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vsyslog(pri, fmt, ap);
va_end(ap);
}
void
vsyslog(pri, fmt, ap)
int pri;
const char *fmt;
_BSD_VA_LIST_ ap;
{
size_t cnt;
char ch, *p, *t;
time_t now;
struct tm tmnow;
int fd, saved_errno, tries;
#define TBUF_LEN 2048
#define FMT_LEN 1024
char *stdp = NULL; /* pacify gcc */
char tbuf[TBUF_LEN], fmt_cpy[FMT_LEN];
size_t tbuf_left, fmt_left, prlen;
#define INTERNALLOG LOG_ERR|LOG_CONS|LOG_PERROR|LOG_PID
/* Check for invalid bits. */
if (pri & ~(LOG_PRIMASK|LOG_FACMASK)) {
syslog(INTERNALLOG,
"syslog: unknown facility/priority: %x", pri);
pri &= LOG_PRIMASK|LOG_FACMASK;
}
/* Check priority against setlogmask values. */
if (!(LOG_MASK(LOG_PRI(pri)) & LogMask))
return;
saved_errno = errno;
/* Set default facility if none specified. */
if ((pri & LOG_FACMASK) == 0)
pri |= LogFacility;
/* Build the message. */
/*
* Although it's tempting, we can't ignore the possibility of
* overflowing the buffer when assembling the "fixed" portion
* of the message. Strftime's "%h" directive expands to the
* locale's abbreviated month name, but if the user has the
* ability to construct to his own locale files, it may be
* arbitrarily long.
*/
(void)time(&now);
p = tbuf;
tbuf_left = TBUF_LEN;
#define DEC() \
do { \
if (prlen >= tbuf_left) \
prlen = tbuf_left - 1; \
p += prlen; \
tbuf_left -= prlen; \
} while (ZERO)
prlen = snprintf(p, tbuf_left, "<%d>", pri);
DEC();
tzset(); /* strftime() implies tzset(), localtime_r() doesn't. */
prlen = strftime(p, tbuf_left, "%h %e %T ", localtime_r(&now, &tmnow));
DEC();
if (LogStat & LOG_PERROR)
stdp = p;
if (LogTag == NULL)
LogTag = getprogname();
if (LogTag != NULL) {
prlen = snprintf(p, tbuf_left, "%s", LogTag);
DEC();
}
if (LogStat & LOG_PID) {
prlen = snprintf(p, tbuf_left, "[%d]", getpid());
DEC();
}
if (LogTag != NULL) {
if (tbuf_left > 1) {
*p++ = ':';
tbuf_left--;
}
if (tbuf_left > 1) {
*p++ = ' ';
tbuf_left--;
}
}
/*
* We wouldn't need this mess if printf handled %m, or if
* strerror() had been invented before syslog().
*/
for (t = fmt_cpy, fmt_left = FMT_LEN; (ch = *fmt) != '\0'; ++fmt) {
if (ch == '%' && fmt[1] == 'm') {
++fmt;
prlen = snprintf(t, fmt_left, "%s",
strerror(saved_errno));
if (prlen >= fmt_left)
prlen = fmt_left - 1;
t += prlen;
fmt_left -= prlen;
} else {
if (fmt_left > 1) {
*t++ = ch;
fmt_left--;
}
}
}
*t = '\0';
prlen = vsnprintf(p, tbuf_left, fmt_cpy, ap);
DEC();
cnt = p - tbuf;
/* Output to stderr if requested. */
if (LogStat & LOG_PERROR) {
struct iovec iov[2];
iov[0].iov_base = stdp;
iov[0].iov_len = cnt - (stdp - tbuf);
iov[1].iov_base = "\n";
iov[1].iov_len = 1;
(void)writev(STDERR_FILENO, iov, 2);
}
/* Get connected, output the message to the local logger. */
mutex_lock(&syslog_mutex);
/*
* Try to send it twice. If the first try fails, we might
* be able to simply reconnect and send the message (which
* means syslogd was restarted since we connected the first
* time). If the second attempt doesn't work, then something
* else is wrong and there's probably not much we can do
* here.
*/
for (tries = 1; tries <= 2; tries++) {
if (!connected)
openlog_unlocked(LogTag, LogStat | LOG_NDELAY, 0);
if (send(LogFile, tbuf, cnt, 0) >= 0) {
mutex_unlock(&syslog_mutex);
return;
}
else
closelog_unlocked();
}
mutex_unlock(&syslog_mutex);
/*
* Output the message to the console; don't worry about blocking,
* if console blocks everything will. Make sure the error reported
* is the one from the syslogd failure.
*/
if (LogStat & LOG_CONS &&
(fd = open(_PATH_CONSOLE, O_WRONLY, 0)) >= 0) {
struct iovec iov[2];
p = strchr(tbuf, '>') + 1;
iov[0].iov_base = p;
iov[0].iov_len = cnt - (p - tbuf);
iov[1].iov_base = "\r\n";
iov[1].iov_len = 2;
(void)writev(fd, iov, 2);
(void)close(fd);
}
}
static struct sockaddr_un SyslogAddr; /* AF_LOCAL address of local logger */
static void
openlog_unlocked(ident, logstat, logfac)
const char *ident;
int logstat, logfac;
{
if (ident != NULL)
LogTag = ident;
LogStat = logstat;
if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
LogFacility = logfac;
if (LogFile == -1) {
SyslogAddr.sun_family = AF_LOCAL;
(void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
sizeof(SyslogAddr.sun_path));
if (LogStat & LOG_NDELAY) {
if ((LogFile = socket(AF_LOCAL, SOCK_DGRAM, 0)) == -1)
return;
(void)fcntl(LogFile, F_SETFD, 1);
}
}
if (LogFile != -1 && !connected) {
if (connect(LogFile, (struct sockaddr *)(void *)&SyslogAddr,
SUN_LEN(&SyslogAddr)) == -1) {
(void)close(LogFile);
LogFile = -1;
} else
connected = 1;
}
}
void
openlog(ident, logstat, logfac)
const char *ident;
int logstat, logfac;
{
mutex_lock(&syslog_mutex);
openlog_unlocked(ident, logstat, logfac);
mutex_unlock(&syslog_mutex);
}
static void
closelog_unlocked()
{
(void)close(LogFile);
LogFile = -1;
connected = 0;
}
void
closelog()
{
mutex_lock(&syslog_mutex);
closelog_unlocked();
mutex_unlock(&syslog_mutex);
}
/* setlogmask -- set the log mask level */
int
setlogmask(pmask)
int pmask;
{
int omask;
omask = LogMask;
if (pmask != 0)
LogMask = pmask;
return (omask);
}