ns_maint.c

早期freebsd实现

#if !defined(lint) && !defined(SABER)
static char sccsid[] = "@(#)ns_maint.c	4.39 (Berkeley) 3/2/91";
static char rcsid[] = "$Id: ns_maint.c,v 4.9.1.9 1993/12/06 00:43:02 vixie Exp $";
#endif /* not lint */

/*
 * ++Copyright++ 1986, 1988
 * -
 * Copyright (c) 1986, 1988
 *    The Regents of the University of California.  All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 * 	This product includes software developed by the University of
 * 	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * -
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 * -
 * --Copyright--
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <sys/wait.h>
#include <stdio.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>

#include "named.h"

#ifdef USE_UTIME
# include <utime.h>
#endif

static int		xfers_running,	/* # of xfers running */
			xfers_deferred,	/* # of needed xfers not run yet */
			alarm_pending;

static void		startxfer __P((struct zoneinfo *)),
			abortxfer __P((struct zoneinfo *)),
			qserial_query __P((struct zoneinfo *)),
			tryxfer __P((void));

/*
 * Invoked at regular intervals by signal interrupt; refresh all secondary
 * zones from primary name server and remove old cache entries.  Also,
 * ifdef'd ALLOW_UPDATES, dump database if it has changed since last
 * dump/bootup.
 */
void
ns_maint()
{
	register struct zoneinfo *zp;
	int zonenum;

	gettime(&tt);

	dprintf(1, (ddt, "\nns_maint(); now %s", ctime(&tt.tv_sec)));

	xfers_deferred = 0;
	alarm_pending = 0;
	for (zp = zones, zonenum = 0; zp < &zones[nzones]; zp++, zonenum++) {
#ifdef DEBUG
		if (debug >= 2)
			printzoneinfo(zonenum);
#endif
		if (tt.tv_sec >= zp->z_time && zp->z_refresh > 0) {
			/*
			 * Set default time for next action first,
			 * so that it can be changed later if necessary.
			 */
			zp->z_time = tt.tv_sec + zp->z_refresh;

			switch (zp->z_type) {

			case Z_CACHE:
				doachkpt();
				break;

			case Z_SECONDARY:
#ifdef STUBS
			case Z_STUB:
#endif
				if ((zp->z_state & Z_NEED_RELOAD) == 0) {
				    if (zp->z_state & Z_XFER_RUNNING)
					abortxfer(zp);
				    else if (!(zp->z_state & Z_QSERIAL))
					qserial_query(zp);
				}
				break;
#ifdef ALLOW_UPDATES
			case Z_PRIMARY:
				/*
				 * Checkpoint the zone if it has changed
				 * since we last checkpointed
				 */
				if (zp->z_state & Z_CHANGED)
					zonedump(zp);
				break;
#endif /* ALLOW_UPDATES */
			}
			gettime(&tt);
		}
	}
	sched_maint();
	dprintf(1, (ddt, "exit ns_maint()\n"));
}

/*
 * Find when the next refresh needs to be and set
 * interrupt time accordingly.
 */
void
sched_maint()
{
	register struct zoneinfo *zp;
	struct itimerval ival;
	time_t next_refresh = 0;
	static time_t next_alarm;

	for (zp = zones; zp < &zones[nzones]; zp++)
		if (zp->z_time != 0 &&
		    (next_refresh == 0 || next_refresh > zp->z_time))
			next_refresh = zp->z_time;
        /*
	 *  Schedule the next call to ns_maint.
	 *  Don't visit any sooner than maint_interval.
	 */
	bzero((char *)&ival, sizeof (ival));
	if (next_refresh != 0) {
		if (next_refresh == next_alarm && alarm_pending) {
			dprintf(1, (ddt, "sched_maint: no schedule change\n"));
			return;
		}
		/*
		 *  tv_sec can be an unsigned long, so we can't let
		 *  it go negative.
		 */
		if (next_refresh < tt.tv_sec)
			next_refresh = tt.tv_sec;
		ival.it_value.tv_sec = next_refresh - tt.tv_sec;
		if ((long) ival.it_value.tv_sec < maint_interval)
			ival.it_value.tv_sec = maint_interval;
		next_alarm = next_refresh;
		alarm_pending = 1;
	}
	(void) setitimer(ITIMER_REAL, &ival, (struct itimerval *)NULL);
	dprintf(1, (ddt, "sched_maint: Next interrupt in %d sec\n",
		    ival.it_value.tv_sec));
}

/*
 * Mark a zone "up to date" after named-xfer tells us this or we
 * discover it through the qserial_*() logic.
 */
static void
markUpToDate(zp)
	struct zoneinfo *zp;
{
	zp->z_state &= ~Z_SYSLOGGED;
	zp->z_lastupdate = tt.tv_sec;
	zp->z_time = tt.tv_sec + zp->z_refresh;
	/*
	 * Restore Z_AUTH in case expired,
	 * but only if there were no errors
	 * in the zone file.
	 */
	if ((zp->z_state & Z_DB_BAD) == 0)
		zp->z_state |= Z_AUTH;
	if (zp->z_source) {
#if defined(USE_UTIME)
		struct utimbuf t;

		t.actime = tt.tv_sec;
		t.modtime = tt.tv_sec;
		(void) utime(zp->z_source, &t);
#else
		struct timeval t[2];

		t[0] = tt;
		t[1] = tt;
		(void) utimes(zp->z_source, t);
#endif /* USE_UTIME */
	}
}

/*
 * Query for the serial number of a zone, so that
 * we can check to see if we need to transfer it.
 */
static void
qserial_query(zp)
	struct zoneinfo *zp;
{
	struct qinfo *qp;

	dprintf(1, (ddt, "qserial_query(%s)\n", zp->z_origin));
	qp = sysquery(zp->z_origin, zp->z_class, T_SOA,
		      zp->z_addr, zp->z_addrcnt);
	if (!qp) {
		dprintf(1, (ddt, "qserial_query(%s) FAILED\n", zp->z_origin));
		return;		/* XXX - this is bad, we should do something */
	}
	qp->q_flags |= Q_ZSERIAL;
	qp->q_zquery = zp;
	zp->z_state |= Z_QSERIAL;
	dprintf(1, (ddt, "qserial_query(%s) QUEUED\n", zp->z_origin));
}

void
qserial_answer(qp, serial)
	struct qinfo *qp;
	u_int32_t serial;
{
	struct zoneinfo *zp = qp->q_zquery;

	dprintf(1, (ddt, "qserial_answer(%s, %lu)\n", zp->z_origin, serial));
	zp->z_state &= ~Z_QSERIAL;
	if (serial == 0) {
		/* an error occurred, or the query timed out, or this is
		 * the qremove() being called from ns_resp after calling us.
		 * we have already turned off the Z_QSERIAL bit, so just 
		 * return.  this is _not_ an error.
		 */
		return;
	}
	if (SEQ_GT(serial, zp->z_serial)) {
		dprintf(1, (ddt, "qserial_answer: zone is out of date\n"));
		zp->z_state |= Z_NEED_XFER;
		zp->z_xaddr = from_addr.sin_addr; /* don't use qp->q_from */
		xfers_deferred++;
		tryxfer();
	} else if (SEQ_GT(zp->z_serial, serial)) {
		dprintf(1, (ddt, "qserial_answer: serial# went backward\n"));
		if (!haveComplained((char*)zp, "went backward")) {
			syslog(LOG_CRIT,
	"Zone \"%s\" SOA serial# (%lu) rcvd from [%s] lower than ours (%lu)\n",
			       zp->z_origin, serial,
			       inet_ntoa(from_addr.sin_addr),
			       zp->z_serial);
		}
	} else {
		dprintf(1, (ddt, "qserial_answer: zone serial is still OK\n"));
		markUpToDate(zp);
	}
}

/*
 * Start an asynchronous zone transfer for a zone.
 * Depends on current time being in tt.
 * The caller must call sched_maint after startxfer.
 */
static void
startxfer(zp)
	struct zoneinfo *zp;
{
	static char *argv[NSMAX + 20], argv_ns[NSMAX][MAXDNAME];
	int cnt, argc = 0, argc_ns = 0, pid, omask;
	char debug_str[10];
	char serial_str[10];
	char port_str[10];
#ifdef GEN_AXFR
	char class_str[10];
#endif

	dprintf(1, (ddt, "startxfer() %s\n", zp->z_origin));

	argv[argc++] = "named-xfer";
	argv[argc++] = "-z";
	argv[argc++] = zp->z_origin;
	argv[argc++] = "-f";
	argv[argc++] = zp->z_source;
	argv[argc++] = "-s";
	sprintf(serial_str, "%lu", zp->z_serial);
	argv[argc++] = serial_str;
#ifdef GEN_AXFR
	argv[argc++] = "-C";
	sprintf(class_str, "%d", zp->z_class);
	argv[argc++] = class_str;
#endif
 	if (zp->z_state & Z_SYSLOGGED)
		argv[argc++] = "-q";
	argv[argc++] = "-P";
	sprintf(port_str, "%d", ns_port);
	argv[argc++] = port_str;
#ifdef STUBS