syslogd.c

linux下记录系统日志代码以及记录内核日志代码

				/* open the terminal */
				ttyf = open(p, O_WRONLY|O_NOCTTY);
				if (ttyf >= 0) {
					struct stat statb;

					if (fstat(ttyf, &statb) == 0 &&
					    (statb.st_mode & S_IWRITE))
						(void) writev(ttyf, iov, 6);
					close(ttyf);
					ttyf = -1;
				}
			}
			(void) alarm(0);
		}
		exit(0);
	}
	/* close the user login file */
	endutent();
	reenter = 0;
}

void reapchild()
{
	int saved_errno = errno;
#if defined(SYSV) && !defined(linux)
	(void) signal(SIGCHLD, reapchild);	/* reset signal handler -ASP */
	wait ((int *)0);
#else
	union wait status;

	while (wait3(&status, WNOHANG, (struct rusage *) NULL) > 0)
		;
#endif
#ifdef linux
	(void) signal(SIGCHLD, reapchild);	/* reset signal handler -ASP */
#endif
	errno = saved_errno;
}

/*
 * Return a printable representation of a host address.
 */
const char *cvthname(f)
	struct sockaddr_in *f;
{
	struct hostent *hp;
	register char *p;
	int count;

	if (f->sin_family != AF_INET) {
		dprintf("Malformed from address.\n");
		return ("???");
	}
	hp = gethostbyaddr((char *) &f->sin_addr, sizeof(struct in_addr), \
			   f->sin_family);
	if (hp == 0) {
		dprintf("Host name for your address (%s) unknown.\n",
			inet_ntoa(f->sin_addr));
		return (inet_ntoa(f->sin_addr));
	}
	/*
	 * Convert to lower case, just like LocalDomain above
	 */
	for (p = (char *)hp->h_name; *p ; p++)
		if (isupper(*p))
			*p = tolower(*p);

	/*
	 * Notice that the string still contains the fqdn, but your
	 * hostname and domain are separated by a '\0'.
	 */
	if ((p = strchr(hp->h_name, '.'))) {
		if (strcmp(p + 1, LocalDomain) == 0) {
			*p = '\0';
			return (hp->h_name);
		} else {
			if (StripDomains) {
				count=0;
				while (StripDomains[count]) {
					if (strcmp(p + 1, StripDomains[count]) == 0) {
						*p = '\0';
						return (hp->h_name);
					}
					count++;
				}
			}
			if (LocalHosts) {
				count=0;
				while (LocalHosts[count]) {
					if (!strcmp(hp->h_name, LocalHosts[count])) {
						*p = '\0';
						return (hp->h_name);
					}
					count++;
				}
			}
		}
	}

	return (hp->h_name);
}

void domark()
{
	register struct filed *f;
#ifdef SYSV
	int lognum;
#endif

	if (MarkInterval > 0) {
	now = time(0);
	MarkSeq += TIMERINTVL;
	if (MarkSeq >= MarkInterval) {
		logmsg(LOG_INFO, "-- MARK --", LocalHostName, ADDDATE|MARK);
		MarkSeq = 0;
	}

#ifdef SYSV
	for (lognum = 0; lognum <= nlogs; lognum++) {
		f = &Files[lognum];
#else
	for (f = Files; f; f = f->f_next) {
#endif
		if (f->f_prevcount && now >= REPEATTIME(f)) {
			dprintf("flush %s: repeated %d times, %d sec.\n",
			    TypeNames[f->f_type], f->f_prevcount,
			    repeatinterval[f->f_repeatcount]);
			fprintlog(f, LocalHostName, 0, (char *)NULL);
			BACKOFF(f);
		}
	}
	}
	(void) signal(SIGALRM, domark);
	(void) alarm(TIMERINTVL);
}

void debug_switch()

{
	dprintf("Switching debugging_on to %s\n", (debugging_on == 0) ? "true" : "false");
	debugging_on = (debugging_on == 0) ? 1 : 0;
	signal(SIGUSR1, debug_switch);
}


/*
 * Print syslogd errors some place.
 */
void logerror(type)
	char *type;
{
	char buf[100];

	dprintf("Called logerr, msg: %s\n", type);

	if (errno == 0)
		(void) snprintf(buf, sizeof(buf), "syslogd: %s", type);
	else
		(void) snprintf(buf, sizeof(buf), "syslogd: %s: %s", type, strerror(errno));
	errno = 0;
	logmsg(LOG_SYSLOG|LOG_ERR, buf, LocalHostName, ADDDATE);
	return;
}

void die(sig)

	int sig;
	
{
	register struct filed *f;
	char buf[100];
	int lognum;
	int i;
	int was_initialized = Initialized;

	Initialized = 0;	/* Don't log SIGCHLDs in case we
				   receive one during exiting */

	for (lognum = 0; lognum <= nlogs; lognum++) {
		f = &Files[lognum];
		/* flush any pending output */
		if (f->f_prevcount)
			fprintlog(f, LocalHostName, 0, (char *)NULL);
	}

	Initialized = was_initialized;
	if (sig) {
		dprintf("syslogd: exiting on signal %d\n", sig);
		(void) snprintf(buf, sizeof(buf), "exiting on signal %d", sig);
		errno = 0;
		logmsg(LOG_SYSLOG|LOG_INFO, buf, LocalHostName, ADDDATE);
	}

	/* Close the UNIX sockets. */
        for (i = 0; i < nfunix; i++)
		if (funix[i] != -1)
			close(funix[i]);
	/* Close the inet socket. */
	if (InetInuse) close(inetm);

	/* Clean-up files. */
        for (i = 0; i < nfunix; i++)
		if (funixn[i] && funix[i] != -1)
			(void)unlink(funixn[i]);
#ifndef TESTING
	(void) remove_pid(PidFile);
#endif
	exit(0);
}

/*
 * Signal handler to terminate the parent process.
 */
#ifndef TESTING
void doexit(sig)
	int sig;
{
	exit (0);
}
#endif

/*
 *  INIT -- Initialize syslogd from configuration table
 */

void init()
{
	register int i, lognum;
	register FILE *cf;
	register struct filed *f;
#ifndef TESTING
#ifndef SYSV
	register struct filed **nextp = (struct filed **) 0;
#endif
#endif
	register char *p;
	register unsigned int Forwarding = 0;
#ifdef CONT_LINE
	char cbuf[BUFSIZ];
	char *cline;
#else
	char cline[BUFSIZ];
#endif
	struct servent *sp;

	sp = getservbyname("syslog", "udp");
	if (sp == NULL) {
		errno = 0;
		logerror("network logging disabled (syslog/udp service unknown).");
		logerror("see syslogd(8) for details of whether and how to enable it.");
		return;
	}
	LogPort = sp->s_port;

	/*
	 *  Close all open log files and free log descriptor array.
	 */
	dprintf("Called init.\n");
	Initialized = 0;
	if ( nlogs > -1 )
	{
		dprintf("Initializing log structures.\n");

		for (lognum = 0; lognum <= nlogs; lognum++ ) {
			f = &Files[lognum];

			/* flush any pending output */
			if (f->f_prevcount)
				fprintlog(f, LocalHostName, 0, (char *)NULL);

			switch (f->f_type) {
				case F_FILE:
				case F_PIPE:
				case F_TTY:
				case F_CONSOLE:
					(void) close(f->f_file);
				break;
			}
		}

		/*
		 * This is needed especially when HUPing syslogd as the
		 * structure would grow infinitively.  -Joey
		 */
		nlogs = -1;
		free((void *) Files);
		Files = (struct filed *) 0;
	}
	

#ifdef SYSV
	lognum = 0;
#else
	f = NULL;
#endif

	/* open the configuration file */
	if ((cf = fopen(ConfFile, "r")) == NULL) {
		dprintf("cannot open %s.\n", ConfFile);
#ifdef SYSV
		allocate_log();
		f = &Files[lognum++];
#ifndef TESTING
		cfline("*.err\t" _PATH_CONSOLE, f);
#else
		snprintf(cbuf,sizeof(cbuf), "*.*\t%s", ttyname(0));
		cfline(cbuf, f);
#endif
#else
		*nextp = (struct filed *)calloc(1, sizeof(*f));
		cfline("*.ERR\t" _PATH_CONSOLE, *nextp);
		(*nextp)->f_next = (struct filed *)calloc(1, sizeof(*f))	/* ASP */
		cfline("*.PANIC\t*", (*nextp)->f_next);
#endif
		Initialized = 1;
		return;
	}

	/*
	 *  Foreach line in the conf table, open that file.
	 */
#if CONT_LINE
	cline = cbuf;
	while (fgets(cline, sizeof(cbuf) - (cline - cbuf), cf) != NULL) {
#else
	while (fgets(cline, sizeof(cline), cf) != NULL) {
#endif
		/*
		 * check for end-of-section, comments, strip off trailing
		 * spaces and newline character.
		 */
		for (p = cline; isspace(*p); ++p);
		if (*p == '\0' || *p == '#')
			continue;
#if CONT_LINE
		strcpy(cline, p);
#endif
		for (p = strchr(cline, '\0'); isspace(*--p););
#if CONT_LINE
		if (*p == '\\') {
			if ((p - cbuf) > BUFSIZ - 30) {
				/* Oops the buffer is full - what now? */
				cline = cbuf;
			} else {
				*p = 0;
				cline = p;
				continue;
			}
		}  else
			cline = cbuf;
#endif
		*++p = '\0';
#ifndef SYSV
		f = (struct filed *)calloc(1, sizeof(*f));
		*nextp = f;
		nextp = &f->f_next;
#endif
		allocate_log();
		f = &Files[lognum++];
#if CONT_LINE
		cfline(cbuf, f);
#else
		cfline(cline, f);
#endif
		if (f->f_type == F_FORW || f->f_type == F_FORW_SUSP || f->f_type == F_FORW_UNKN) {
			Forwarding++;
		}
	}

	/* close the configuration file */
	(void) fclose(cf);

#ifdef SYSLOG_UNIXAF
	for (i = 0; i < nfunix; i++) {
		if (funix[i] != -1)
			/* Don't close the socket, preserve it instead
			close(funix[i]);
			*/
			continue;
		if ((funix[i] = create_unix_socket(funixn[i])) != -1)
			dprintf("Opened UNIX socket `%s'.\n", funixn[i]);
	}
#endif

#ifdef SYSLOG_INET
	if (Forwarding || AcceptRemote) {
		if (finet < 0) {
			finet = create_inet_socket();
			if (finet >= 0) {
				InetInuse = 1;
				dprintf("Opened syslog UDP port.\n");
			}
		}
	}
	else {
		if (finet >= 0)
			close(finet);
		finet = -1;
		InetInuse = 0;
	}
	inetm = finet;
#endif

	Initialized = 1;

	if ( Debug ) {
#ifdef SYSV
		for (lognum = 0; lognum <= nlogs; lognum++) {
			f = &Files[lognum];
			if (f->f_type != F_UNUSED) {
				printf ("%2d: ", lognum);
#else
		for (f = Files; f; f = f->f_next) {
			if (f->f_type != F_UNUSED) {
#endif
				for (i = 0; i <= LOG_NFACILITIES; i++)
					if (f->f_pmask[i] == TABLE_NOPRI)
						printf(" X ");
					else
						printf("%2X ", f->f_pmask[i]);
				printf("%s: ", TypeNames[f->f_type]);
				switch (f->f_type) {
				case F_FILE:
				case F_PIPE:
				case F_TTY:
				case F_CONSOLE:
					printf("%s", f->f_un.f_fname);
					if (f->f_file == -1)
						printf(" (unused)");
					break;

				case F_FORW:
				case F_FORW_SUSP:
				case F_FORW_UNKN:
					printf("%s", f->f_un.f_forw.f_hname);
					break;

				case F_USERS:
					for (i = 0; i < MAXUNAMES && *f->f_un.f_uname[i]; i++)
						printf("%s, ", f->f_un.f_uname[i]);
					break;
				}
				printf("\n");
			}
		}
	}

	if ( AcceptRemote )
#ifdef DEBRELEASE
		logmsg(LOG_SYSLOG|LOG_INFO, "syslogd " VERSION "." PATCHLEVEL "#" DEBRELEASE \
		       ": restart (remote reception)." , LocalHostName, \
		       	ADDDATE);
#else
		logmsg(LOG_SYSLOG|LOG_INFO, "syslogd " VERSION "." PATCHLEVEL \
		       ": restart (remote reception)." , LocalHostName, \
		       	ADDDATE);
#endif
	else
#ifdef DEBRELEASE
		logmsg(LOG_SYSLOG|LOG_INFO, "syslogd " VERSION "." PATCHLEVEL "#" DEBRELEASE \
		       ": restart." , LocalHostName, ADDDATE);
#else
		logmsg(LOG_SYSLOG|LOG_INFO, "syslogd " VERSION "." PATCHLEVEL \
		       ": restart." , LocalHostName, ADDDATE);
#endif
	(void) signal(SIGHUP, sighup_handler);
	dprintf("syslogd: restarted.\n");
}
#if FALSE
	}}} /* balance parentheses for emacs */
#endif

/*
 * Crack a configuration file line
 */

void cfline(line, f)
	char *line;
	register struct filed *f;
{
	register char *p;
	register char *q;
	register int i, i2;
	char *bp;
	int pri;
	int singlpri = 0;