syslogd.c

手机嵌入式Linux下可用的busybox源码

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){
static const int IOV_COUNT = 2;
		struct iovec iov[IOV_COUNT];
		struct iovec *v = iov;

		memset(&res, 0, 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);
writev_retry:
		if ( -1 == writev(remotefd,iov, IOV_COUNT)){
			if (errno == EINTR) goto writev_retry;
			error_msg_and_die("cannot write to remote file handle on"
					"%s:%d",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(LOG_SYSLOG | LOG_INFO, "System log daemon exiting.");
	unlink(lfile);
#ifdef BB_FEATURE_IPC_SYSLOG
	ipcsyslog_cleanup();
#endif

	exit(TRUE);
}

static void domark(int sig)
{
	if (MarkInterval > 0) {
		logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --");
		alarm(MarkInterval);
	}
}

/* This must be a #define, since when DODEBUG and BUFFERS_GO_IN_BSS are
 * enabled, we otherwise get a "storage size isn't constant error. */
static int serveConnection (char* tmpbuf, int n_read)
{
	char *p = tmpbuf;

	while (p < tmpbuf + n_read) {

		int           pri = (LOG_USER | LOG_NOTICE);
		char          line[ MAXLINE + 1 ];
		unsigned char c;

		char *q = line;

		while ( (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';
		p++;
		/* Now log it */
		logMessage (pri, line);
	}
	return n_read;
}


#ifdef BB_FEATURE_REMOTE_LOG
static void init_RemoteLog (void)
{

  struct sockaddr_in remoteaddr;
  struct hostent *hostinfo;
  int len = sizeof(remoteaddr);

  memset(&remoteaddr, 0, len);

  remotefd = socket(AF_INET, SOCK_DGRAM, 0);

  if (remotefd < 0) {
    error_msg_and_die("cannot create socket");
  }

  hostinfo = xgethostbyname(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("cannot connect to remote host %s:%d", 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;

	/* 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. */
	if (realpath (_PATH_LOG, lfile) != NULL)
		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_DGRAM, 0)) < 0)
		perror_msg_and_die ("Couldn't get file descriptor for socket " _PATH_LOG);

	addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path);
	if (bind(sock_fd, (struct sockaddr *) &sunx, addrLength) < 0)
		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);


#ifdef BB_FEATURE_IPC_SYSLOG
	if (circular_logging == TRUE ){
	   ipcsyslog_init();
	}
#endif

#ifdef BB_FEATURE_REMOTE_LOG
	if (doRemoteLog == TRUE){
	  init_RemoteLog();
	}
#endif

	logMessage (LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER);

	for (;;) {

		FD_ZERO (&fds);
		FD_SET (sock_fd, &fds);

		if (select (sock_fd+1, &fds, NULL, NULL, NULL) < 0) {
			if (errno == EINTR) {
				/* alarm may have happened. */
				continue;
			}
			perror_msg_and_die ("select error");
		}

		if (FD_ISSET (sock_fd, &fds)) {
		       int   i;
		       RESERVE_BB_BUFFER(tmpbuf, BUFSIZ + 1);

		       memset(tmpbuf, '\0', BUFSIZ+1);
		       if ( (i = recv(sock_fd, tmpbuf, BUFSIZ, 0)) > 0) {
			       serveConnection(tmpbuf, i);
		       } else {
			       perror_msg_and_die ("UNIX socket error");
		       }
		       RELEASE_BB_BUFFER (tmpbuf);
		}/* FD_ISSET() */
	} /* for main loop */
}

extern int syslogd_main(int argc, char **argv)
{
	int opt;
#if ! defined(__uClinux__)
	int doFork = TRUE;
#endif

	char *p;

	/* do normal option parsing */
	while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) {
		switch (opt) {
			case 'm':
				MarkInterval = atoi(optarg) * 60;
				break;
#if ! defined(__uClinux__)
			case 'n':
				doFork = FALSE;
				break;
#endif
			case 'O':
				logFilePath = xstrdup(optarg);
				break;
#ifdef BB_FEATURE_REMOTE_LOG
			case 'R':
				RemoteHost = xstrdup(optarg);
				if ( (p = strchr(RemoteHost, ':'))){
					RemotePort = atoi(p+1);
					*p = '\0';
				}
				doRemoteLog = TRUE;
				break;
			case 'L':
				local_logging = TRUE;
				break;
#endif
#ifdef BB_FEATURE_IPC_SYSLOG
			case 'C':
				circular_logging = TRUE;
				break;
#endif
			default:
				show_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);

#if ! defined(__uClinux__)
	if (doFork == TRUE) {
		if (daemon(0, 1) < 0)
			perror_msg_and_die("daemon");
	}
#endif
	doSyslogd();

	return EXIT_SUCCESS;
}

/*
Local Variables
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/