syslogd.c

早期freebsd实现

	}
	(void)sigsetmask(omask);
}

void
fprintlog(f, flags, msg)
	struct filed *f;
	int flags;
	char *msg;
{
	struct iovec iov[6];
	struct iovec *v;
	int l;
	char line[MAXLINE + 1], repbuf[80], greetings[200];

	v = iov;
	if (f->f_type == F_WALL) {
		v->iov_base = greetings;
		v->iov_len = sprintf(greetings,
		    "\r\n\7Message from syslogd@%s at %.24s ...\r\n",
		    f->f_prevhost, ctime(&now));
		v++;
		v->iov_base = "";
		v->iov_len = 0;
		v++;
	} else {
		v->iov_base = f->f_lasttime;
		v->iov_len = 15;
		v++;
		v->iov_base = " ";
		v->iov_len = 1;
		v++;
	}
	v->iov_base = f->f_prevhost;
	v->iov_len = strlen(v->iov_base);
	v++;
	v->iov_base = " ";
	v->iov_len = 1;
	v++;

	if (msg) {
		v->iov_base = msg;
		v->iov_len = strlen(msg);
	} else if (f->f_prevcount > 1) {
		v->iov_base = repbuf;
		v->iov_len = sprintf(repbuf, "last message repeated %d times",
		    f->f_prevcount);
	} else {
		v->iov_base = f->f_prevline;
		v->iov_len = f->f_prevlen;
	}
	v++;

	dprintf("Logging to %s", TypeNames[f->f_type]);
	f->f_time = now;

	switch (f->f_type) {
	case F_UNUSED:
		dprintf("\n");
		break;

	case F_FORW:
		dprintf(" %s\n", f->f_un.f_forw.f_hname);
		l = sprintf(line, "<%d>%.15s %s", f->f_prevpri,
		    iov[0].iov_base, iov[4].iov_base);
		if (l > MAXLINE)
			l = MAXLINE;
		if (sendto(finet, line, l, 0,
		    (struct sockaddr *)&f->f_un.f_forw.f_addr,
		    sizeof(f->f_un.f_forw.f_addr)) != l) {
			int e = errno;
			(void)close(f->f_file);
			f->f_type = F_UNUSED;
			errno = e;
			logerror("sendto");
		}
		break;

	case F_CONSOLE:
		if (flags & IGN_CONS) {
			dprintf(" (ignored)\n");
			break;
		}
		/* FALLTHROUGH */

	case F_TTY:
	case F_FILE:
		dprintf(" %s\n", f->f_un.f_fname);
		if (f->f_type != F_FILE) {
			v->iov_base = "\r\n";
			v->iov_len = 2;
		} else {
			v->iov_base = "\n";
			v->iov_len = 1;
		}
	again:
		if (writev(f->f_file, iov, 6) < 0) {
			int e = errno;
			(void)close(f->f_file);
			/*
			 * Check for errors on TTY's due to loss of tty
			 */
			if ((e == EIO || e == EBADF) && f->f_type != F_FILE) {
				f->f_file = open(f->f_un.f_fname,
				    O_WRONLY|O_APPEND, 0);
				if (f->f_file < 0) {
					f->f_type = F_UNUSED;
					logerror(f->f_un.f_fname);
				} else
					goto again;
			} else {
				f->f_type = F_UNUSED;
				errno = e;
				logerror(f->f_un.f_fname);
			}
		} else if (flags & SYNC_FILE)
			(void)fsync(f->f_file);
		break;

	case F_USERS:
	case F_WALL:
		dprintf("\n");
		v->iov_base = "\r\n";
		v->iov_len = 2;
		wallmsg(f, iov);
		break;
	}
	f->f_prevcount = 0;
}

/*
 *  WALLMSG -- Write a message to the world at large
 *
 *	Write the specified message to either the entire
 *	world, or a list of approved users.
 */
void
wallmsg(f, iov)
	struct filed *f;
	struct iovec *iov;
{
	static int reenter;			/* avoid calling ourselves */
	FILE *uf;
	struct utmp ut;
	int i;
	char *p;
	char line[sizeof(ut.ut_line) + 1];

	if (reenter++)
		return;
	if ((uf = fopen(_PATH_UTMP, "r")) == NULL) {
		logerror(_PATH_UTMP);
		reenter = 0;
		return;
	}
	/* NOSTRICT */
	while (fread((char *)&ut, sizeof(ut), 1, uf) == 1) {
		if (ut.ut_name[0] == '\0')
			continue;
		strncpy(line, ut.ut_line, sizeof(ut.ut_line));
		line[sizeof(ut.ut_line)] = '\0';
		if (f->f_type == F_WALL) {
			if ((p = ttymsg(iov, 6, line, 60*5)) != NULL) {
				errno = 0;	/* already in msg */
				logerror(p);
			}
			continue;
		}
		/* should we send the message to this user? */
		for (i = 0; i < MAXUNAMES; i++) {
			if (!f->f_un.f_uname[i][0])
				break;
			if (!strncmp(f->f_un.f_uname[i], ut.ut_name,
			    UT_NAMESIZE)) {
				if ((p = ttymsg(iov, 6, line, 60*5)) != NULL) {
					errno = 0;	/* already in msg */
					logerror(p);
				}
				break;
			}
		}
	}
	(void)fclose(uf);
	reenter = 0;
}

void
reapchild(signo)
	int signo;
{
	union wait status;

	while (wait3((int *)&status, WNOHANG, (struct rusage *)NULL) > 0)
		;
}

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

	dprintf("cvthname(%s)\n", inet_ntoa(f->sin_addr));

	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));
	}
	if ((p = strchr(hp->h_name, '.')) && strcmp(p + 1, LocalDomain) == 0)
		*p = '\0';
	return (hp->h_name);
}

void
domark(signo)
	int signo;
{
	struct filed *f;

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

	for (f = Files; f; f = f->f_next) {
		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, 0, (char *)NULL);
			BACKOFF(f);
		}
	}
	(void)alarm(TIMERINTVL);
}

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

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

void
die(signo)
	int signo;
{
	struct filed *f;
	char buf[100];

	for (f = Files; f != NULL; f = f->f_next) {
		/* flush any pending output */
		if (f->f_prevcount)
			fprintlog(f, 0, (char *)NULL);
	}
	if (signo) {
		dprintf("syslogd: exiting on signal %d\n", signo);
		(void)sprintf(buf, "exiting on signal %d", signo);
		errno = 0;
		logerror(buf);
	}
	(void)unlink(LogName);
	exit(0);
}

/*
 *  INIT -- Initialize syslogd from configuration table
 */
void
init(signo)
	int signo;
{
	int i;
	FILE *cf;
	struct filed *f, *next, **nextp;
	char *p;
	char cline[LINE_MAX];

	dprintf("init\n");

	/*
	 *  Close all open log files.
	 */
	Initialized = 0;
	for (f = Files; f != NULL; f = next) {
		/* flush any pending output */
		if (f->f_prevcount)
			fprintlog(f, 0, (char *)NULL);

		switch (f->f_type) {
		case F_FILE:
		case F_TTY:
		case F_CONSOLE:
		case F_FORW:
			(void)close(f->f_file);
			break;
		}
		next = f->f_next;
		free((char *)f);
	}
	Files = NULL;
	nextp = &Files;

	/* open the configuration file */
	if ((cf = fopen(ConfFile, "r")) == NULL) {
		dprintf("cannot open %s\n", ConfFile);
		*nextp = (struct filed *)calloc(1, sizeof(*f));
		cfline("*.ERR\t/dev/console", *nextp);
		(*nextp)->f_next = (struct filed *)calloc(1, sizeof(*f));
		cfline("*.PANIC\t*", (*nextp)->f_next);
		Initialized = 1;
		return;
	}

	/*
	 *  Foreach line in the conf table, open that file.
	 */
	f = NULL;
	while (fgets(cline, sizeof(cline), cf) != NULL) {
		/*
		 * check for end-of-section, comments, strip off trailing
		 * spaces and newline character.
		 */
		for (p = cline; isspace(*p); ++p)
			continue;
		if (*p == NULL || *p == '#')
			continue;
		for (p = strchr(cline, '\0'); isspace(*--p);)
			continue;
		*++p = '\0';
		f = (struct filed *)calloc(1, sizeof(*f));
		*nextp = f;
		nextp = &f->f_next;
		cfline(cline, f);
	}

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

	Initialized = 1;

	if (Debug) {
		for (f = Files; f; f = f->f_next) {
			for (i = 0; i <= LOG_NFACILITIES; i++)
				if (f->f_pmask[i] == INTERNAL_NOPRI)
					printf("X ");
				else
					printf("%d ", f->f_pmask[i]);
			printf("%s: ", TypeNames[f->f_type]);
			switch (f->f_type) {
			case F_FILE:
			case F_TTY:
			case F_CONSOLE:
				printf("%s", f->f_un.f_fname);
				break;

			case F_FORW:
				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");
		}
	}

	logmsg(LOG_SYSLOG|LOG_INFO, "syslogd: restart", LocalHostName, ADDDATE);
	dprintf("syslogd: restarted\n");
}

/*
 * Crack a configuration file line
 */
void
cfline(line, f)
	char *line;
	struct filed *f;
{
	struct hostent *hp;
	int i, pri;
	char *bp, *p, *q;
	char buf[MAXLINE], ebuf[100];

	dprintf("cfline(%s)\n", line);

	errno = 0;	/* keep strerror() stuff out of logerror messages */

	/* clear out file entry */
	memset(f, 0, sizeof(*f));
	for (i = 0; i <= LOG_NFACILITIES; i++)
		f->f_pmask[i] = INTERNAL_NOPRI;

	/* scan through the list of selectors */
	for (p = line; *p && *p != '\t';) {

		/* find the end of this facility name list */
		for (q = p; *q && *q != '\t' && *q++ != '.'; )
			continue;

		/* collect priority name */
		for (bp = buf; *q && !strchr("\t,;", *q); )
			*bp++ = *q++;
		*bp = '\0';

		/* skip cruft */
		while (strchr(", ;", *q))
			q++;

		/* decode priority name */
		if (*buf == '*')
			pri = LOG_PRIMASK + 1;
		else {
			pri = decode(buf, prioritynames);
			if (pri < 0) {
				(void)sprintf(ebuf,
				    "unknown priority name \"%s\"", buf);
				logerror(ebuf);
				return;
			}
		}

		/* scan facilities */
		while (*p && !strchr("\t.;", *p)) {
			for (bp = buf; *p && !strchr("\t,;.", *p); )
				*bp++ = *p++;
			*bp = '\0';
			if (*buf == '*')
				for (i = 0; i < LOG_NFACILITIES; i++)
					f->f_pmask[i] = pri;
			else {
				i = decode(buf, facilitynames);
				if (i < 0) {
					(void)sprintf(ebuf,
					    "unknown facility name \"%s\"",
					    buf);
					logerror(ebuf);
					return;
				}
				f->f_pmask[i >> 3] = pri;
			}
			while (*p == ',' || *p == ' ')
				p++;
		}

		p = q;
	}

	/* skip to action part */
	while (*p == '\t')
		p++;

	switch (*p)
	{
	case '@':
		if (!InetInuse)
			break;
		(void)strcpy(f->f_un.f_forw.f_hname, ++p);
		hp = gethostbyname(p);
		if (hp == NULL) {
			extern int h_errno;

			logerror(hstrerror(h_errno));
			break;
		}
		memset(&f->f_un.f_forw.f_addr, 0,
			 sizeof(f->f_un.f_forw.f_addr));
		f->f_un.f_forw.f_addr.sin_family = AF_INET;
		f->f_un.f_forw.f_addr.sin_port = LogPort;
		memmove(&f->f_un.f_forw.f_addr.sin_addr, hp->h_addr, hp->h_length);
		f->f_type = F_FORW;
		break;

	case '/':
		(void)strcpy(f->f_un.f_fname, p);
		if ((f->f_file = open(p, O_WRONLY|O_APPEND, 0)) < 0) {
			f->f_file = F_UNUSED;
			logerror(p);
			break;
		}
		if (isatty(f->f_file))
			f->f_type = F_TTY;
		else
			f->f_type = F_FILE;
		if (strcmp(p, ctty) == 0)
			f->f_type = F_CONSOLE;
		break;

	case '*':
		f->f_type = F_WALL;
		break;

	default:
		for (i = 0; i < MAXUNAMES && *p; i++) {
			for (q = p; *q && *q != ','; )
				q++;
			(void)strncpy(f->f_un.f_uname[i], p, UT_NAMESIZE);
			if ((q - p) > UT_NAMESIZE)
				f->f_un.f_uname[i][UT_NAMESIZE] = '\0';
			else
				f->f_un.f_uname[i][q - p] = '\0';
			while (*q == ',' || *q == ' ')
				q++;
			p = q;
		}
		f->f_type = F_USERS;
		break;
	}
}


/*
 *  Decode a symbolic name to a numeric value
 */
int
decode(name, codetab)
	const char *name;
	CODE *codetab;
{
	CODE *c;
	char *p, buf[40];

	if (isdigit(*name))
		return (atoi(name));

	for (p = buf; *name && p < &buf[sizeof(buf) - 1]; p++, name++) {
		if (isupper(*name))
			*p = tolower(*name);
		else
			*p = *name;
	}
	*p = '\0';
	for (c = codetab; c->c_name; c++)
		if (!strcmp(buf, c->c_name))
			return (c->c_val);

	return (-1);
}