busybox/syslogd.c
1999-12-16 20:59:36 +00:00

405 lines
9.3 KiB
C

/*
* Mini syslogd implementation for busybox
*
* Copyright (C) 1999 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include "internal.h"
#include <stdio.h>
#include <stdarg.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <ctype.h>
#include <netdb.h>
#include <sys/klog.h>
#include <errno.h>
#include <paths.h>
#define ksyslog klogctl
extern int ksyslog(int type, char *buf, int len);
/* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
#define SYSLOG_NAMES
#include <sys/syslog.h>
/* Path for the file where all log messages are written */
#define __LOG_FILE "/var/log/messages"
static char* logFilePath = __LOG_FILE;
/* interval between marks in seconds */
static int MarkInterval = 20*60;
/* localhost's name */
static char LocalHostName[32];
static const char syslogd_usage[] =
"syslogd [OPTION]...\n\n"
"Linux system and kernel (provides klogd) logging utility.\n"
"Note that this version of syslogd/klogd ignores /etc/syslog.conf.\n\n"
"Options:\n"
"\t-m\tChange the mark timestamp interval. default=20min. 0=off\n"
"\t-n\tDo not fork into the background (for when run by init)\n"
#ifdef BB_KLOGD
"\t-K\tDo not start up the klogd process (by default syslogd spawns klogd).\n"
#endif
"\t-O\tSpecify an alternate log file. default=/var/log/messages\n";
/* try to open up the specified device */
static int device_open(char *device, int mode)
{
int m, f, fd = -1;
m = mode | O_NONBLOCK;
/* Retry up to 5 times */
for (f = 0; f < 5; f++)
if ((fd = open(device, m)) >= 0)
break;
if (fd < 0)
return fd;
/* Reset original flags. */
if (m != mode)
fcntl(fd, F_SETFL, mode);
return fd;
}
/* print a message to the log file */
static void message(char *fmt, ...)
{
int fd;
va_list arguments;
if ((fd = device_open(logFilePath, O_WRONLY|O_CREAT|O_NOCTTY|O_APPEND|O_NONBLOCK)) >= 0) {
va_start(arguments, fmt);
vdprintf(fd, fmt, arguments);
va_end(arguments);
close(fd);
} else {
/* Always send console messages to /dev/console so people will see them. */
if ((fd = device_open(_PATH_CONSOLE, O_WRONLY|O_NOCTTY|O_NONBLOCK)) >= 0) {
va_start(arguments, fmt);
vdprintf(fd, fmt, arguments);
va_end(arguments);
close(fd);
} else {
fprintf(stderr, "Bummer, can't print: ");
va_start(arguments, fmt);
vfprintf(stderr, fmt, arguments);
fflush(stderr);
va_end(arguments);
}
}
}
static void logMessage( int pri, char* msg)
{
time_t now;
char *timestamp;
static char res[20];
CODE *c_pri, *c_fac;
for (c_fac=facilitynames; c_fac->c_name && !(c_fac->c_val==LOG_FAC(pri)<<3); c_fac++);
for (c_pri=prioritynames; c_pri->c_name && !(c_pri->c_val==LOG_PRI(pri)); c_pri++);
if (*c_fac->c_name=='\0' || *c_pri->c_name=='\0')
snprintf (res, sizeof(res), "<%d>", pri);
else
snprintf (res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name);
if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' ||
msg[9] != ':' || msg[12] != ':' || msg[15] != ' ')
{
time(&now);
timestamp = ctime(&now) + 4;
timestamp[15] = '\0';
} else {
timestamp = msg;
timestamp[15] = '\0';
msg += 16;
}
/* todo: supress duplicates */
/* now spew out the message to wherever it is supposed to go */
message( "%s %s %s %s\n", timestamp, LocalHostName, res, msg);
}
static void quit_signal(int sig)
{
logMessage(LOG_SYSLOG|LOG_INFO, "System log daemon exiting.");
unlink( _PATH_LOG);
exit( TRUE);
}
static void restart_signal(int sig)
{
/* pretend to restart */
logMessage(LOG_SYSLOG|LOG_INFO, "syslogd restarting");
}
static void domark(int sig)
{
if (MarkInterval > 0) {
logMessage(LOG_SYSLOG|LOG_INFO, "-- MARK --");
alarm(MarkInterval);
}
}
static void doSyslogd(void)
{
struct sockaddr_un sunx;
int fd, conn;
size_t addrLength;
char buf[1024];
char *q, *p = buf;
int readSize;
/* Remove any preexisting socket/file */
unlink(_PATH_LOG);
/* Set up sig handlers */
signal(SIGINT, quit_signal);
signal(SIGTERM, quit_signal);
signal(SIGQUIT, quit_signal);
signal(SIGHUP, restart_signal);
signal(SIGALRM, domark);
alarm(MarkInterval);
unlink( _PATH_LOG);
memset(&sunx, 0, sizeof(sunx));
sunx.sun_family = AF_UNIX; /* Unix domain socket */
strncpy(sunx.sun_path, _PATH_LOG, sizeof(sunx.sun_path));
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0 ) {
perror("Couldn't obtain descriptor for socket " _PATH_LOG);
exit( FALSE);
}
addrLength = sizeof(sunx.sun_family) + strlen(sunx.sun_path);
if ( (bind(fd, (struct sockaddr *) &sunx, addrLength)) ||
(fchmod(fd, 0666) < 0) || (listen(fd, 5)) )
{
perror("Could not connect to socket " _PATH_LOG);
exit( FALSE);
}
logMessage(LOG_SYSLOG|LOG_INFO, "syslogd started: "
"BusyBox v" BB_VER " (" BB_BT ")");
while ((conn = accept(fd, (struct sockaddr *) &sunx,
&addrLength)) >= 0)
{
while ((readSize=read(conn, buf, sizeof(buf))) > 0)
{
char line[1025];
unsigned char c;
int pri = (LOG_USER|LOG_NOTICE);
memset (line, 0, sizeof(line));
p = buf;
q = line;
while ( p && (c = *p) && q < &line[sizeof(line) - 1]) {
if (c == '<') {
/* Parse the magic priority number */
pri = 0;
while (isdigit(*(++p))) {
pri = 10 * pri + (*p - '0');
}
if (pri &~ (LOG_FACMASK|LOG_PRIMASK))
pri = (LOG_USER|LOG_NOTICE);
} else if (c == '\n') {
*q++ = ' ';
} else if (iscntrl(c)&&(c<0177)) {
*q++ = '^';
*q++ = c ^ 0100;
} else {
*q++ = c;
}
p++;
}
*q = '\0';
/* Now log it */
logMessage( pri, line);
}
close(conn);
}
close(fd);
}
#ifdef BB_KLOGD
static void klogd_signal(int sig)
{
ksyslog(7, NULL, 0);
ksyslog(0, 0, 0);
logMessage(LOG_SYSLOG|LOG_INFO, "Kernel log daemon exiting.");
exit( TRUE);
}
static void doKlogd(void)
{
int priority=LOG_INFO;
char log_buffer[4096];
char *logp;
/* Set up sig handlers */
signal(SIGINT, klogd_signal);
signal(SIGKILL, klogd_signal);
signal(SIGTERM, klogd_signal);
signal(SIGHUP, klogd_signal);
logMessage(LOG_SYSLOG|LOG_INFO, "klogd started: "
"BusyBox v" BB_VER " (" BB_BT ")");
ksyslog(1, NULL, 0);
while (1) {
/* Use kernel syscalls */
memset(log_buffer, '\0', sizeof(log_buffer));
if ( ksyslog(2, log_buffer, sizeof(log_buffer)) < 0 ) {
char message[80];
if ( errno == EINTR )
continue;
snprintf(message, 79, "klogd: Error return from sys_sycall: " \
"%d - %s.\n", errno, strerror(errno));
logMessage(LOG_SYSLOG|LOG_ERR, message);
exit(1);
}
logp=log_buffer;
if ( *log_buffer == '<' )
{
switch ( *(log_buffer+1) )
{
case '0':
priority = LOG_EMERG;
break;
case '1':
priority = LOG_ALERT;
break;
case '2':
priority = LOG_CRIT;
break;
case '3':
priority = LOG_ERR;
break;
case '4':
priority = LOG_WARNING;
break;
case '5':
priority = LOG_NOTICE;
break;
case '6':
priority = LOG_INFO;
break;
case '7':
default:
priority = LOG_DEBUG;
}
logp+=3;
}
logMessage(LOG_KERN|priority, logp);
}
}
#endif
extern int syslogd_main(int argc, char **argv)
{
int pid, klogd_pid;
int doFork = TRUE;
#ifdef BB_KLOGD
int startKlogd = TRUE;
#endif
char *p;
char **argv1=argv;
while (--argc > 0 && **(++argv1) == '-') {
while (*(++(*argv1))) {
switch (**argv1) {
case 'm':
if (--argc == 0) {
usage(syslogd_usage);
}
MarkInterval = atoi(*(++argv1))*60;
break;
case 'n':
doFork = FALSE;
break;
#ifdef BB_KLOGD
case 'K':
startKlogd = FALSE;
break;
#endif
case 'O':
if (--argc == 0) {
usage(syslogd_usage);
}
logFilePath = *(++argv1);
break;
default:
usage(syslogd_usage);
}
}
}
/* Store away localhost's name before the fork */
gethostname(LocalHostName, sizeof(LocalHostName));
if ( (p = strchr(LocalHostName, '.')) ) {
*p++ = '\0';
}
if (doFork == TRUE) {
pid = fork();
if ( pid < 0 )
exit( pid);
else if ( pid == 0 ) {
strncpy(argv[0], "syslogd",strlen(argv[0]));
doSyslogd();
}
} else {
doSyslogd();
}
#ifdef BB_KLOGD
/* Start up the klogd process */
if (startKlogd == TRUE) {
klogd_pid = fork();
if (klogd_pid == 0 ) {
strncpy(argv[0], "klogd", strlen(argv[0]));
doKlogd();
}
}
#endif
exit( TRUE);
}