InfoMagic Internet Tools 1993 July/Internet Tools.iso/RockRidge/mail/sendmail/sendmail-5.65c+IDA-1.4.4.1/support/syslog.c

C/C++ Source or Header | 1989-01-19 | 4.9 KB | 203 lines

/*
 * 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 the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not 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 MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)syslog.c    5.20 (Berkeley) 1/19/89";
#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
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/signal.h>
#include <sys/syslog.h>
#include <netdb.h>
#include <strings.h>
#include <varargs.h>
#include <stdio.h>

#define    LOGNAME    "/dev/log"
#define    CONSOLE    "/dev/console"

static int    LogFile = -1;        /* fd for log */
static int    connected;        /* have done connect */
static int    LogStat = 0;        /* status bits, set by openlog() */
static char    *LogTag = "syslog";    /* string to tag the entry with */
static int    LogFacility = LOG_USER;    /* default facility code */

syslog(pri, fmt, args)
    int pri, args;
    char *fmt;
{
    vsyslog(pri, fmt, &args);
}

vsyslog(pri, fmt, ap)
    int pri;
    register char *fmt;
    va_list ap;
{
    extern int errno;
    register int cnt;
    register char *p;
    time_t now, time();
    int pid, saved_errno;
    char tbuf[2048], fmt_cpy[1024], *ctime();

    saved_errno = errno;

    /* see if we should just throw out this message */
    if ((u_int)LOG_FAC(pri) >= LOG_NFACILITIES ||
        !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 (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; ++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);

    /* output the message to the local logger */
    if (send(LogFile, tbuf, cnt = strlen(tbuf), 0) >= 0 ||
        !(LogStat&LOG_CONS))
        return;

    /* output the message to the console */
    pid = vfork();
    if (pid == -1)
        return;
    if (pid == 0) {
        int fd;
        long sigsetmask();

        (void)signal(SIGALRM, SIG_DFL);
        sigsetmask((long)~sigmask(SIGALRM));
        (void)alarm((u_int)5);
        if ((fd = open(CONSOLE, O_WRONLY, 0)) < 0)
            return;
        (void)alarm((u_int)0);
        (void)strcat(tbuf, "\r");
        p = index(tbuf, '>') + 1;
        (void)write(fd, p, cnt + 1 - (p - tbuf));
        (void)close(fd);
        _exit(0);
    }
    if (!(LogStat & LOG_NOWAIT))
        while ((cnt = wait((int *)0)) > 0 && cnt != pid);
}

static struct sockaddr SyslogAddr;    /* AF_UNIX address of local logger */
/*
 * OPENLOG -- open system log
 */
openlog(ident, logstat, logfac)
    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.sa_family = AF_UNIX;
        strncpy(SyslogAddr.sa_data, LOGNAME, sizeof SyslogAddr.sa_data);
        if (LogStat & LOG_NDELAY) {
            LogFile = socket(AF_UNIX, SOCK_DGRAM, 0);
            fcntl(LogFile, F_SETFD, 1);
        }
    }
    if (LogFile != -1 && !connected &&
        connect(LogFile, &SyslogAddr, sizeof(SyslogAddr)) != -1)
        connected = 1;
}

/*
 * CLOSELOG -- close the system log
 */
closelog()
{
    (void) close(LogFile);
    LogFile = -1;
    connected = 0;
}

static int    LogMask = 0xff;        /* mask of priorities to be logged */
/*
 * SETLOGMASK -- set the log mask level
 */
setlogmask(pmask)
    int pmask;
{
    int omask;

    omask = LogMask;
    if (pmask != 0)
        LogMask = pmask;
    return (omask);
}