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0810f723b137cb73d41b9021b3ea945f98001159
busybox/syslogd.c

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/* vi: set sw=4 ts=4: */
/*
* Mini syslogd implementation for busybox
*
* Copyright (C) 1999,2000 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
*
* Copyright (C) 2000 by Karl M. Hegbloom <karlheg@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 "busybox.h"
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <paths.h>
#include <signal.h>
#include <stdarg.h>
#include <time.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <sys/param.h>
#if ! defined __GLIBC__ && ! defined __UCLIBC__
typedef unsigned int socklen_t;
#ifndef __alpha__
# define __NR_klogctl __NR_syslog
static inline _syscall3(int, klogctl, int, type, char *, b, int, len);
#else /* __alpha__ */
#define klogctl syslog
#endif
#else
# include <sys/klog.h>
#endif
/* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
#define SYSLOG_NAMES
#include <sys/syslog.h>
#include <sys/uio.h>
/* Path for the file where all log messages are written */
#define __LOG_FILE "/var/log/messages"
/* Path to the unix socket */
char lfile[BUFSIZ] = "";
static char *logFilePath = __LOG_FILE;
/* interval between marks in seconds */
static int MarkInterval = 20 * 60;
/* localhost's name */
static char LocalHostName[32];
#ifdef BB_FEATURE_REMOTE_LOG
#include <netinet/in.h>
/* udp socket for logging to remote host */
static int remotefd = -1;
/* where do we log? */
static char *RemoteHost;
/* what port to log to? */
static int RemotePort = 514;
/* To remote log or not to remote log, that is the question. */
static int doRemoteLog = FALSE;
static int local_logging = FALSE;
#endif
/* Note: There is also a function called "message()" in init.c */
/* Print a message to the log file. */
static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
static void message (char *fmt, ...)
{
int fd;
struct flock fl;
va_list arguments;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 1;
if ((fd = device_open (logFilePath,
O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND |
O_NONBLOCK)) >= 0) {
fl.l_type = F_WRLCK;
fcntl (fd, F_SETLKW, &fl);
va_start (arguments, fmt);
vdprintf (fd, fmt, arguments);
va_end (arguments);
fl.l_type = F_UNLCK;
fcntl (fd, F_SETLKW, &fl);
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;
if (pri != 0) {
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 == NULL || c_pri->c_name == NULL)
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 */
#ifdef BB_FEATURE_REMOTE_LOG
/* send message to remote logger */
if ( -1 != remotefd){
#define IOV_COUNT 2
struct iovec iov[IOV_COUNT];
struct iovec *v = iov;
bzero(&res, sizeof(res));
snprintf(res, sizeof(res), "<%d>", pri);
v->iov_base = res ;
v->iov_len = strlen(res);
v++;
v->iov_base = msg;
v->iov_len = strlen(msg);
if ( -1 == writev(remotefd,iov, IOV_COUNT)){
error_msg_and_die("syslogd: cannot write to remote file handle on"
"%s:%d\n",RemoteHost,RemotePort);
}
}
if (local_logging == TRUE)
#endif
/* 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(0, "System log daemon exiting.");
unlink(lfile);
exit(TRUE);
}
static void domark(int sig)
{
if (MarkInterval > 0) {
logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
alarm(MarkInterval);
}
}
#define BUFSIZE 1023
static int serveConnection (int conn)
{
char buf[ BUFSIZE + 1 ];
int n_read;
while ((n_read = read (conn, buf, BUFSIZE )) > 0) {
int pri = (LOG_USER | LOG_NOTICE);
char line[ BUFSIZE + 1 ];
unsigned char c;
char *p = buf, *q = line;
buf[ n_read - 1 ] = '\0';
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);
}
return (0);
}
#ifdef BB_FEATURE_REMOTE_LOG
static void init_RemoteLog (void){
struct sockaddr_in remoteaddr;
struct hostent *hostinfo;
int len = sizeof(remoteaddr);
bzero(&remoteaddr, len);
remotefd = socket(AF_INET, SOCK_DGRAM, 0);
if (remotefd < 0) {
error_msg_and_die("syslogd: cannot create socket\n");
}
hostinfo = (struct hostent *) gethostbyname(RemoteHost);
if (!hostinfo) {
error_msg_and_die("syslogd: cannot resolve remote host name [%s]\n", RemoteHost);
}
remoteaddr.sin_family = AF_INET;
remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
remoteaddr.sin_port = htons(RemotePort);
/*
Since we are using UDP sockets, connect just sets the default host and port
for future operations
*/
if ( 0 != (connect(remotefd, (struct sockaddr *) &remoteaddr, len))){
error_msg_and_die("syslogd: cannot connect to remote host %s:%d\n", RemoteHost, RemotePort);
}
}
#endif
static void doSyslogd (void) __attribute__ ((noreturn));
static void doSyslogd (void)
{
struct sockaddr_un sunx;
socklen_t addrLength;
int sock_fd;
fd_set fds;
char lfile[BUFSIZ];
/* Set up signal handlers. */
signal (SIGINT, quit_signal);
signal (SIGTERM, quit_signal);
signal (SIGQUIT, quit_signal);
signal (SIGHUP, SIG_IGN);
signal (SIGCHLD, SIG_IGN);
#ifdef SIGCLD
signal (SIGCLD, SIG_IGN);
#endif
signal (SIGALRM, domark);
alarm (MarkInterval);
/* Create the syslog file so realpath() can work. */
close (open (_PATH_LOG, O_RDWR | O_CREAT, 0644));
if (realpath (_PATH_LOG, lfile) == NULL)
perror_msg_and_die ("Could not resolve path to " _PATH_LOG);
unlink (lfile);
memset (&sunx, 0, sizeof (sunx));
sunx.sun_family = AF_UNIX;
strncpy (sunx.sun_path, lfile, sizeof (sunx.sun_path));
if ((sock_fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
perror_msg_and_die ("Couldn't obtain descriptor for socket " _PATH_LOG);
addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
if ((bind (sock_fd, (struct sockaddr *) &sunx, addrLength)) || (listen (sock_fd, 5)))
perror_msg_and_die ("Could not connect to socket " _PATH_LOG);
if (chmod (lfile, 0666) < 0)
perror_msg_and_die ("Could not set permission on " _PATH_LOG);
FD_ZERO (&fds);
FD_SET (sock_fd, &fds);
#ifdef BB_FEATURE_REMOTE_LOG
if (doRemoteLog == TRUE){
init_RemoteLog();
}
#endif
logMessage (0, "syslogd started: BusyBox v" BB_VER " (" BB_BT ")");
for (;;) {
fd_set readfds;
int n_ready;
int fd;
memcpy (&readfds, &fds, sizeof (fds));
if ((n_ready = select (FD_SETSIZE, &readfds, NULL, NULL, NULL)) < 0) {
if (errno == EINTR) continue; /* alarm may have happened. */
perror_msg_and_die ("select error");
}
for (fd = 0; (n_ready > 0) && (fd < FD_SETSIZE); fd++) {
if (FD_ISSET (fd, &readfds)) {
--n_ready;
if (fd == sock_fd) {
int conn;
pid_t pid;
if ((conn = accept (sock_fd, (struct sockaddr *) &sunx, &addrLength)) < 0) {
perror_msg_and_die ("accept error");
}
pid = fork();
if (pid < 0) {
perror ("syslogd: fork");
close (conn);
continue;
}
if (pid == 0) {
serveConnection (conn);
close (conn);
exit( TRUE);
}
close (conn);
}
}
}
}
}
#ifdef BB_FEATURE_KLOGD
static void klogd_signal(int sig)
{
klogctl(7, NULL, 0);
klogctl(0, 0, 0);
logMessage(0, "Kernel log daemon exiting.");
exit(TRUE);
}
static void doKlogd (void) __attribute__ ((noreturn));
static void doKlogd (void)
{
int priority = LOG_INFO;
char log_buffer[4096];
int i, n, lastc;
char *start;
/* Set up sig handlers */
signal(SIGINT, klogd_signal);
signal(SIGKILL, klogd_signal);
signal(SIGTERM, klogd_signal);
signal(SIGHUP, SIG_IGN);
#ifdef BB_FEATURE_REMOTE_LOG
if (doRemoteLog == TRUE){
init_RemoteLog();
}
#endif
logMessage(0, "klogd started: "
"BusyBox v" BB_VER " (" BB_BT ")");
/* "Open the log. Currently a NOP." */
klogctl(1, NULL, 0);
while (1) {
/* Use kernel syscalls */
memset(log_buffer, '\0', sizeof(log_buffer));
n = klogctl(2, log_buffer, sizeof(log_buffer));
if (n < 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);
}
/* klogctl buffer parsing modelled after code in dmesg.c */
start=&log_buffer[0];
lastc='\0';
for (i=0; i<n; i++) {
if (lastc == '\0' && log_buffer[i] == '<') {
priority = 0;
i++;
while (isdigit(log_buffer[i])) {
priority = priority*10+(log_buffer[i]-'0');
i++;
}
if (log_buffer[i] == '>') i++;
start = &log_buffer[i];
}
if (log_buffer[i] == '\n') {
log_buffer[i] = '\0'; /* zero terminate this message */
logMessage(LOG_KERN | priority, start);
start = &log_buffer[i+1];
priority = LOG_INFO;
}
lastc = log_buffer[i];
}
}
}
#endif
static void daemon_init (char **argv, char *dz, void fn (void))
{
setsid();
chdir ("/");
strncpy(argv[0], dz, strlen(argv[0]));
fn();
exit(0);
}
extern int syslogd_main(int argc, char **argv)
{
int opt, pid, klogd_pid;
int doFork = TRUE;
#ifdef BB_FEATURE_KLOGD
int startKlogd = TRUE;
#endif
char *p;
/* do normal option parsing */
while ((opt = getopt(argc, argv, "m:nKO:R:L")) > 0) {
switch (opt) {
case 'm':
MarkInterval = atoi(optarg) * 60;
break;
case 'n':
doFork = FALSE;
break;
#ifdef BB_FEATURE_KLOGD
case 'K':
startKlogd = FALSE;
break;
#endif
case 'O':
logFilePath = strdup(optarg);
break;
#ifdef BB_FEATURE_REMOTE_LOG
case 'R':
RemoteHost = strdup(optarg);
if ( (p = strchr(RemoteHost, ':'))){
RemotePort = atoi(p+1);
*p = '\0';
}
doRemoteLog = TRUE;
break;
case 'L':
local_logging = TRUE;
break;
#endif
default:
usage(syslogd_usage);
}
}
#ifdef BB_FEATURE_REMOTE_LOG
/* If they have not specified remote logging, then log locally */
if (doRemoteLog == FALSE)
local_logging = TRUE;
#endif
/* Store away localhost's name before the fork */
gethostname(LocalHostName, sizeof(LocalHostName));
if ((p = strchr(LocalHostName, '.'))) {
*p++ = '\0';
}
umask(0);
#ifdef BB_FEATURE_KLOGD
/* Start up the klogd process */
if (startKlogd == TRUE) {
klogd_pid = fork();
if (klogd_pid == 0) {
daemon_init (argv, "klogd", doKlogd);
}
}
#endif
if (doFork == TRUE) {
pid = fork();
if (pid < 0)
exit(pid);
else if (pid == 0) {
daemon_init (argv, "syslogd", doSyslogd);
}
} else {
doSyslogd();
}
return EXIT_SUCCESS;
}
/*
Local Variables
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/
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