sysklogd/syslog.c
1997-06-02 17:21:41 +00:00

244 lines
5.8 KiB
C

/*
* Copyright (c) 1983, 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted provided
* that: (1) source distributions retain this entire copyright notice and
* comment, and (2) distributions including binaries display the following
* acknowledgement: ``This product includes software developed by the
* University of California, Berkeley and its contributors'' in the
* documentation or other materials provided with the distribution and in
* all advertising materials mentioning features or use of this software.
* 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)syslog.c 5.28 (Berkeley) 6/27/90";
#endif /* LIBC_SCCS and not lint */
/*
* SYSLOG -- print message on log file
*
* This routine looks a lot like printf, except that it outputs to the
* log file instead of the standard output. Also:
* adds a timestamp,
* prints the module name in front of the message,
* has some other formatting types (or will sometime),
* adds a newline on the end of the message.
*
* The output of this routine is intended to be read by syslogd(8).
*
* Author: Eric Allman
* Modified to use UNIX domain IPC by Ralph Campbell
*
* Sat Dec 11 11:58:31 CST 1993: Dr. Wettstein
* Changes to allow compilation with no complains under -Wall.
*
* Thu Jan 18 11:16:11 CST 1996: Dr. Wettstein
* Added patch to close potential security hole. This is the same
* patch which was announced in the linux-security mailing lists
* and incorporated into the libc version of syslog.c.
*
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/signal.h>
#include <sys/syslog.h>
#if 0
#include "syslog.h"
#include "pathnames.h"
#endif
#include <sys/uio.h>
#include <sys/wait.h>
#include <netdb.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <stdarg.h>
#include <paths.h>
#include <stdio.h>
#define _PATH_LOGNAME "/dev/log"
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 = "syslog"; /* string to tag the entry with */
static int LogFacility = LOG_USER; /* default facility code */
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;
{
register int cnt;
register char *p;
time_t now;
int fd, saved_errno;
char tbuf[2048], fmt_cpy[1024], *stdp = (char *) 0;
saved_errno = errno;
/* see if we should just throw out this message */
if (!LOG_MASK(LOG_PRI(pri)) || (pri &~ (LOG_PRIMASK|LOG_FACMASK)))
return;
if (LogFile < 0 || !connected)
openlog(LogTag, LogStat | LOG_NDELAY, 0);
/* set default facility if none specified */
if ((pri & LOG_FACMASK) == 0)
pri |= LogFacility;
/* build the message */
(void)time(&now);
(void)sprintf(tbuf, "<%d>%.15s ", pri, ctime(&now) + 4);
for (p = tbuf; *p; ++p);
if (LogStat & LOG_PERROR)
stdp = p;
if (LogTag) {
(void)strcpy(p, LogTag);
for (; *p; ++p);
}
if (LogStat & LOG_PID) {
(void)sprintf(p, "[%d]", getpid());
for (; *p; ++p);
}
if (LogTag) {
*p++ = ':';
*p++ = ' ';
}
/* substitute error message for %m */
{
register char ch, *t1, *t2;
char *strerror();
for (t1 = fmt_cpy;
(ch = *fmt) != '\0' && t1<fmt_cpy+sizeof(fmt_cpy);
++fmt)
if (ch == '%' && fmt[1] == 'm') {
++fmt;
for (t2 = strerror(saved_errno);
(*t1 = *t2++); ++t1);
}
else
*t1++ = ch;
*t1 = '\0';
}
(void)vsprintf(p, fmt_cpy, ap);
cnt = strlen(tbuf);
/* output to stderr if requested */
if (LogStat & LOG_PERROR) {
struct iovec iov[2];
register 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(2, iov, 2);
}
/* output the message to the local logger */
if (write(LogFile, tbuf, cnt + 1) >= 0 || !(LogStat&LOG_CONS))
return;
/*
* output the message to the console; don't worry about
* blocking, if console blocks everything will.
*/
if ((fd = open(_PATH_CONSOLE, O_WRONLY|O_NOCTTY, 0)) < 0)
return;
(void)strcat(tbuf, "\r\n");
cnt += 2;
p = index(tbuf, '>') + 1;
(void)write(fd, p, cnt - (p - tbuf));
(void)close(fd);
}
static struct sockaddr SyslogAddr; /* AF_UNIX address of local logger */
/*
* OPENLOG -- open system log
*/
void
openlog(ident, logstat, logfac)
const char *ident;
int logstat, logfac;
{
if (ident != NULL)
LogTag = ident;
LogStat = logstat;
#ifdef ALLOW_KERNEL_LOGGING
if ((logfac &~ LOG_FACMASK) == 0)
#else
if (logfac != 0 && (logfac &~ LOG_FACMASK) == 0)
#endif
LogFacility = logfac;
if (LogFile == -1) {
SyslogAddr.sa_family = AF_UNIX;
strncpy(SyslogAddr.sa_data, _PATH_LOGNAME,
sizeof(SyslogAddr.sa_data));
if (LogStat & LOG_NDELAY) {
LogFile = socket(AF_UNIX, SOCK_STREAM, 0);
/* fcntl(LogFile, F_SETFD, 1); */
}
}
if (LogFile != -1 && !connected &&
connect(LogFile, &SyslogAddr, sizeof(SyslogAddr.sa_family)+
strlen(SyslogAddr.sa_data)) != -1)
connected = 1;
}
/*
* CLOSELOG -- close the system log
*/
void
closelog()
{
(void) close(LogFile);
LogFile = -1;
connected = 0;
}
static int LogMask = 0xff; /* mask of priorities to be logged */
/*
* SETLOGMASK -- set the log mask level
*/
int
setlogmask(pmask)
int pmask;
{
int omask;
omask = LogMask;
if (pmask != 0)
LogMask = pmask;
return (omask);
}