glibc/misc/syslog.c

351 lines
9.1 KiB
C

/*
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)syslog.c 8.4 (Berkeley) 3/18/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/uio.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <stdlib.h>
#include <bits/libc-lock.h>
#include <signal.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
static int LogType = SOCK_DGRAM; /* type of socket connection */
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 */
extern char *__progname; /* Program name, from crt0. */
/* Define the lock. */
__libc_lock_define_initialized (static, syslog_lock)
static void openlog_internal(const char *, int, int) internal_function;
static void closelog_internal(void);
static void sigpipe_handler (int);
#ifdef _LIBC_REENTRANT
static void cancel_handler (void *);
#endif
/*
* syslog, vsyslog --
* print message on log file; output is intended for syslogd(8).
*/
void
#if __STDC__
syslog(int pri, const char *fmt, ...)
#else
syslog(pri, fmt, va_alist)
int pri;
char *fmt;
va_dcl
#endif
{
va_list ap;
#if __STDC__
va_start(ap, fmt);
#else
va_start(ap);
#endif
vsyslog(pri, fmt, ap);
va_end(ap);
}
void
vsyslog(pri, fmt, ap)
int pri;
register const char *fmt;
va_list ap;
{
struct tm now_tm;
time_t now;
int fd;
FILE *f;
char *buf = 0;
size_t bufsize = 0;
size_t prioff, msgoff;
struct sigaction action, oldaction;
struct sigaction *oldaction_ptr = NULL;
int sigpipe;
#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;
/* Set default facility if none specified. */
if ((pri & LOG_FACMASK) == 0)
pri |= LogFacility;
/* Build the message in a memory-buffer stream. */
f = open_memstream (&buf, &bufsize);
prioff = fprintf (f, "<%d>", pri);
(void) time (&now);
#ifdef USE_IN_LIBIO
f->_IO_write_ptr += strftime (f->_IO_write_ptr,
f->_IO_write_end - f->_IO_write_ptr,
"%h %e %T ",
__localtime_r (&now, &now_tm));
#else
f->__bufp += strftime (f->__bufp, f->__put_limit - f->__bufp,
"%h %e %T ", __localtime_r (&now, &now_tm));
#endif
msgoff = ftell (f);
if (LogTag == NULL)
LogTag = __progname;
if (LogTag != NULL)
fputs (LogTag, f);
if (LogStat & LOG_PID)
fprintf (f, "[%d]", getpid ());
if (LogTag != NULL)
putc (':', f), putc (' ', f);
/* We have the header. Print the user's format into the buffer. */
vfprintf (f, fmt, ap);
/* Close the memory stream; this will finalize the data
into a malloc'd buffer in BUF. */
fclose (f);
/* Output to stderr if requested. */
if (LogStat & LOG_PERROR) {
struct iovec iov[2];
register struct iovec *v = iov;
v->iov_base = buf + msgoff;
v->iov_len = bufsize - msgoff;
++v;
v->iov_base = (char *) "\n";
v->iov_len = 1;
(void)writev(STDERR_FILENO, iov, 2);
}
/* Prepare for multiple users. We have to take care: open and
write are cancellation points. */
__libc_cleanup_region_start ((void (*) (void *)) cancel_handler,
&oldaction_ptr);
__libc_lock_lock (syslog_lock);
/* Prepare for a broken connection. */
memset (&action, 0, sizeof (action));
action.sa_handler = sigpipe_handler;
sigemptyset (&action.sa_mask);
sigpipe = sigaction (SIGPIPE, &action, &oldaction);
if (sigpipe == 0)
oldaction_ptr = &oldaction;
/* Get connected, output the message to the local logger. */
if (!connected)
openlog_internal(LogTag, LogStat | LOG_NDELAY, 0);
/* If we have a SOCK_STREAM connection, also send ASCII NUL as
a record terminator. */
if (LogType == SOCK_STREAM)
++bufsize;
if (!connected || __send(LogFile, buf, bufsize, 0) < 0)
{
closelog_internal (); /* attempt re-open next time */
/*
* 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|O_NOCTTY, 0)) >= 0)
{
dprintf (fd, "%s\r\n", buf + msgoff);
(void)close(fd);
}
}
if (sigpipe == 0)
sigaction (SIGPIPE, &oldaction, (struct sigaction *) NULL);
/* End of critical section. */
__libc_cleanup_region_end (0);
__libc_lock_unlock (syslog_lock);
free (buf);
}
static struct sockaddr SyslogAddr; /* AF_UNIX address of local logger */
static void
internal_function
openlog_internal(const char *ident, int logstat, int logfac)
{
if (ident != NULL)
LogTag = ident;
LogStat = logstat;
if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
LogFacility = logfac;
while (1) {
if (LogFile == -1) {
SyslogAddr.sa_family = AF_UNIX;
(void)strncpy(SyslogAddr.sa_data, _PATH_LOG,
sizeof(SyslogAddr.sa_data));
if (LogStat & LOG_NDELAY) {
if ((LogFile = __socket(AF_UNIX, LogType, 0))
== -1)
return;
(void)fcntl(LogFile, F_SETFD, 1);
}
}
if (LogFile != -1 && !connected)
{
int old_errno = errno;
if (__connect(LogFile, &SyslogAddr, sizeof(SyslogAddr))
== -1)
{
int saved_errno = errno;
(void)close(LogFile);
LogFile = -1;
if (LogType == SOCK_DGRAM
&& saved_errno == EPROTOTYPE)
{
/* retry with next SOCK_STREAM: */
LogType = SOCK_STREAM;
__set_errno (old_errno);
continue;
}
} else
connected = 1;
}
break;
}
}
void
openlog (const char *ident, int logstat, int logfac)
{
/* Protect against multiple users. */
__libc_cleanup_region_start ((void (*) __P ((void *))) __libc_mutex_unlock,
&syslog_lock);
__libc_lock_lock (syslog_lock);
openlog_internal (ident, logstat, logfac);
/* Free the lock. */
__libc_cleanup_region_end (1);
}
static void
sigpipe_handler (int signo)
{
closelog_internal ();
}
static void
closelog_internal()
{
if (!connected)
return;
close (LogFile);
LogFile = -1;
connected = 0;
LogTag = NULL;
}
void
closelog ()
{
/* Protect against multiple users. */
__libc_cleanup_region_start ((void (*) __P ((void *))) __libc_mutex_unlock,
&syslog_lock);
__libc_lock_lock (syslog_lock);
closelog_internal ();
/* Free the lock. */
__libc_cleanup_region_end (1);
}
#ifdef _LIBC_REENTRANT
static void
cancel_handler (void *ptr)
{
/* Restore the old signal handler. */
struct sigaction *oldaction = *((struct sigaction **) ptr);
if (oldaction != (struct sigaction *) NULL)
sigaction (SIGPIPE, oldaction, (struct sigaction *) NULL);
/* Free the lock. */
__libc_lock_unlock (syslog_lock);
}
#endif
/* setlogmask -- set the log mask level */
int
setlogmask(pmask)
int pmask;
{
int omask;
omask = LogMask;
if (pmask != 0)
LogMask = pmask;
return (omask);
}