FreeBSD-5.3/lib/libc/gen/syslog.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 8.5 (Berkeley) 4/29/95";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/gen/syslog.c,v 1.30 2004/05/10 17:12:52 dds Exp $");
#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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <stdarg.h>
#include "un-namespace.h"
#include "libc_private.h"
static int LogFile = -1; /* fd for log */
static int connected; /* have done connect */
static int opened; /* have done openlog() */
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 disconnectlog(void); /* disconnect from syslogd */
static void connectlog(void); /* (re)connect to syslogd */
/*
* Format of the magic cookie passed through the stdio hook
*/
struct bufcookie {
char *base; /* start of buffer */
int left;
};
/*
* stdio write hook for writing to a static string buffer
* XXX: Maybe one day, dynamically allocate it so that the line length
* is `unlimited'.
*/
static
int writehook(cookie, buf, len)
void *cookie; /* really [struct bufcookie *] */
char *buf; /* characters to copy */
int len; /* length to copy */
{
struct bufcookie *h; /* private `handle' */
h = (struct bufcookie *)cookie;
if (len > h->left) {
/* clip in case of wraparound */
len = h->left;
}
if (len > 0) {
(void)memcpy(h->base, buf, len); /* `write' it. */
h->base += len;
h->left -= len;
}
return 0;
}
/*
* 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;
va_list ap;
{
int cnt;
char ch, *p;
time_t now;
int fd, saved_errno;
char *stdp, tbuf[2048], fmt_cpy[1024], timbuf[26];
FILE *fp, *fmt_fp;
struct bufcookie tbuf_cookie;
struct bufcookie fmt_cookie;
#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;
/* Create the primary stdio hook */
tbuf_cookie.base = tbuf;
tbuf_cookie.left = sizeof(tbuf);
fp = fwopen(&tbuf_cookie, writehook);
if (fp == NULL)
return;
/* Build the message. */
(void)time(&now);
(void)fprintf(fp, "<%d>", pri);
(void)fprintf(fp, "%.15s ", ctime_r(&now, timbuf) + 4);
if (LogStat & LOG_PERROR) {
/* Transfer to string buffer */
(void)fflush(fp);
stdp = tbuf + (sizeof(tbuf) - tbuf_cookie.left);
}
if (LogTag == NULL)
LogTag = _getprogname();
if (LogTag != NULL)
(void)fprintf(fp, "%s", LogTag);
if (LogStat & LOG_PID)
(void)fprintf(fp, "[%d]", getpid());
if (LogTag != NULL) {
(void)fprintf(fp, ": ");
}
/* Check to see if we can skip expanding the %m */
if (strstr(fmt, "%m")) {
/* Create the second stdio hook */
fmt_cookie.base = fmt_cpy;
fmt_cookie.left = sizeof(fmt_cpy) - 1;
fmt_fp = fwopen(&fmt_cookie, writehook);
if (fmt_fp == NULL) {
fclose(fp);
return;
}
/*
* Substitute error message for %m. Be careful not to
* molest an escaped percent "%%m". We want to pass it
* on untouched as the format is later parsed by vfprintf.
*/
for ( ; (ch = *fmt); ++fmt) {
if (ch == '%' && fmt[1] == 'm') {
++fmt;
fputs(strerror(saved_errno), fmt_fp);
} else if (ch == '%' && fmt[1] == '%') {
++fmt;
fputc(ch, fmt_fp);
fputc(ch, fmt_fp);
} else {
fputc(ch, fmt_fp);
}
}
/* Null terminate if room */
fputc(0, fmt_fp);
fclose(fmt_fp);
/* Guarantee null termination */
fmt_cpy[sizeof(fmt_cpy) - 1] = '\0';
fmt = fmt_cpy;
}
(void)vfprintf(fp, fmt, ap);
(void)fclose(fp);
cnt = sizeof(tbuf) - tbuf_cookie.left;
/* Remove a trailing newline */
if (tbuf[cnt - 1] == '\n')
cnt--;
/* Output to stderr if requested. */
if (LogStat & LOG_PERROR) {
struct iovec iov[2];
struct iovec *v = iov;
v->iov_base = stdp;
v->iov_len = cnt - (stdp - tbuf);
++v;
v->iov_base = "\n";
v->iov_len = 1;
(void)_writev(STDERR_FILENO, iov, 2);
}
/* Get connected, output the message to the local logger. */
if (!opened)
openlog(LogTag, LogStat | LOG_NDELAY, 0);
connectlog();
if (send(LogFile, tbuf, cnt, 0) >= 0)
return;
/*
* If the send() failed, the odds are syslogd was restarted.
* Make one (only) attempt to reconnect to /dev/log.
*/
disconnectlog();
connectlog();
if (send(LogFile, tbuf, cnt, 0) >= 0)
return;
/*
* Output the message to the console; try not to block
* as a blocking console should not stop other processes.
* Make sure the error reported is the one from the syslogd failure.
*/
if (LogStat & LOG_CONS &&
(fd = _open(_PATH_CONSOLE, O_WRONLY|O_NONBLOCK, 0)) >= 0) {
struct iovec iov[2];
struct iovec *v = iov;
p = strchr(tbuf, '>') + 1;
v->iov_base = p;
v->iov_len = cnt - (p - tbuf);
++v;
v->iov_base = "\r\n";
v->iov_len = 2;
(void)_writev(fd, iov, 2);
(void)_close(fd);
}
}
static void
disconnectlog()
{
/*
* If the user closed the FD and opened another in the same slot,
* that's their problem. They should close it before calling on
* system services.
*/
if (LogFile != -1) {
_close(LogFile);
LogFile = -1;
}
connected = 0; /* retry connect */
}
static void
connectlog()
{
struct sockaddr_un SyslogAddr; /* AF_UNIX address of local logger */
if (LogFile == -1) {
if ((LogFile = _socket(AF_UNIX, SOCK_DGRAM, 0)) == -1)
return;
(void)_fcntl(LogFile, F_SETFD, 1);
}
if (LogFile != -1 && !connected) {
SyslogAddr.sun_len = sizeof(SyslogAddr);
SyslogAddr.sun_family = AF_UNIX;
(void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
sizeof SyslogAddr.sun_path);
connected = _connect(LogFile, (struct sockaddr *)&SyslogAddr,
sizeof(SyslogAddr)) != -1;
if (!connected) {
/*
* Try the old "/dev/log" path, for backward
* compatibility.
*/
(void)strncpy(SyslogAddr.sun_path, _PATH_OLDLOG,
sizeof SyslogAddr.sun_path);
connected = _connect(LogFile,
(struct sockaddr *)&SyslogAddr,
sizeof(SyslogAddr)) != -1;
}
if (!connected) {
(void)_close(LogFile);
LogFile = -1;
}
}
}
void
openlog(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 (LogStat & LOG_NDELAY) /* open immediately */
connectlog();
opened = 1; /* ident and facility has been set */
}
void
closelog()
{
(void)_close(LogFile);
LogFile = -1;
LogTag = NULL;
connected = 0;
}
/* setlogmask -- set the log mask level */
int
setlogmask(pmask)
int pmask;
{
int omask;
omask = LogMask;
if (pmask != 0)
LogMask = pmask;
return (omask);
}