busybox/sysklogd/syslogd.c
Eric Andersen 3843e96252 Stuf
1999-11-25 07:30:46 +00:00

297 lines
7.1 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 <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>
/* 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"
/* Path to the current console device */
#define __DEV_CONSOLE "/dev/console"
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 logging utility.\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"
"\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(__DEV_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, "syslogd exiting");
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 --");
signal(SIGALRM, domark);
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);
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(PF_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)) ||
(chmod(_PATH_LOG, 0666) < 0) ||
(listen(fd, 5)) )
{
perror("Could not connect to socket " _PATH_LOG);
exit( FALSE);
}
/* Get localhost's name */
gethostname(LocalHostName, sizeof(LocalHostName));
if ( (p = strchr(LocalHostName, '.')) ) {
*p++ = '\0';
}
logMessage(LOG_SYSLOG|LOG_INFO, "syslogd started: "
"BusyBox v" BB_VER " (" BB_BT ") multi-call binary");
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);
}
extern int syslogd_main(int argc, char **argv)
{
int pid;
int doFork = TRUE;
while (--argc > 0 && **(++argv) == '-') {
while (*(++(*argv))) {
switch (**argv) {
case 'm':
if (--argc == 0) {
usage(syslogd_usage);
}
MarkInterval = atoi(*(++argv))*60;
break;
case 'n':
doFork = FALSE;
break;
case 'O':
if (--argc == 0) {
usage(syslogd_usage);
}
logFilePath = *(++argv);
break;
default:
usage(syslogd_usage);
}
}
}
if (doFork == TRUE) {
pid = fork();
if ( pid < 0 )
exit( pid);
else if ( pid == 0 ) {
doSyslogd();
}
} else {
doSyslogd();
}
exit( TRUE);
}