db_dump.c

早期freebsd实现

#if !defined(lint) && !defined(SABER)
static char sccsid[] = "@(#)db_dump.c	4.33 (Berkeley) 3/3/91";
static char rcsid[] = "$Id: db_dump.c,v 4.9.1.2 1993/09/08 00:01:17 vixie Exp $";
#endif /* not lint */

/*
 * ++Copyright++ 1986, 1988, 1990
 * -
 * Copyright (c) 1986, 1988, 1990
 *    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/stat.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#include <resolv.h>
#include <errno.h>

#include "named.h"

static int		scan_root __P((struct hashbuf *));

/*
 * Dump current cache in a format similar to RFC 883.
 *
 * We try to be careful and determine whether the operation succeeded
 * so that the new cache file can be installed.
 */

void
doachkpt()
{
    FILE *fp;
    char tmpcheckfile[256];

    /* nowhere to checkpoint cache... */
    if (cache_file == NULL) {
	dprintf(3, (ddt, "skipping doachkpt (cache_file == NULL)\n"));
        return;
    }

    dprintf(3, (ddt, "doachkpt()\n"));

    (void) sprintf(tmpcheckfile, "%s.chk", cache_file);
    if ((fp = fopen(tmpcheckfile, "w")) == NULL) {
	dprintf(3, (ddt,
		    "doachkpt(can't open %s for write)\n", tmpcheckfile));
        return;
    }

    (void) gettime(&tt);
    fprintf(fp, "; Dumped at %s", ctime(&tt.tv_sec));
    fflush(fp);
    if (ferror(fp)) {
	dprintf(3, (ddt, "doachkpt(write to checkpoint file failed)\n"));
        return;
    }

    if (fcachetab != NULL) {
	int n = scan_root(hashtab);

	if (n < MINROOTS) {
	    syslog(LOG_ERR, "%d root hints... (too low)", n);
	    fprintf(fp, "; ---- Root hint cache dump ----\n");
	    (void) db_dump(fcachetab, fp, DB_Z_CACHE, "");
	}
    }

    if (hashtab != NULL) {
        fprintf(fp, "; ---- Cache dump ----\n");
        if (db_dump(hashtab, fp, DB_Z_CACHE, "") == NODBFILE) {
	    dprintf(3, (ddt, "doachkpt(checkpoint failed)\n"));
            (void) my_fclose(fp);
            return;
        }
    }

    (void) fsync(fileno(fp));
    if (my_fclose(fp) == EOF) {
        return;
    }

    if (rename(tmpcheckfile, cache_file)) {
	dprintf(3, (ddt, "doachkpt(install %s to %s failed, %d)\n",
		    tmpcheckfile, cache_file, errno));
    }
}

/*
 * What we do is scan the root hint cache to make sure there are at least
 * MINROOTS root pointers with non-0 TTL's so that the checkpoint will not
 * lose the root.  Failing this, all pointers are written out w/ TTL ~0
 * (root pointers timed out and prime_cache() not done or failed).
 */

static int
scan_root(htp)
	struct hashbuf *htp;
{
	register struct databuf *dp;
	register struct namebuf *np;
	struct timeval soon;
	int roots = 0;

	dprintf(1, (ddt, "scan_root(0x%x)\n", htp));

	/* metric by which we determine whether a root NS pointer is still */
	/* valid (will be written out if we do a dump).  we also add some */
	/* time buffer for safety... */
	(void) gettime(&soon);
	soon.tv_sec += TIMBUF;

	for (np = htp->h_tab[0]; np != NULL; np = np->n_next) {
		if (np->n_dname[0] == '\0') {
			dp = np->n_data;
			while (dp != NULL) {
				if (dp->d_type == T_NS &&
				    dp->d_ttl > soon.tv_sec) {
					roots++;
					if (roots >= MINROOTS)
						return (roots);
				}
				dp = dp->d_next;
			}
		}
	}
	return (roots);
}

#ifdef notdef
mark_cache(htp, ttl)
    struct hashbuf *htp;
    int ttl;
{
    register struct databuf *dp;
    register struct namebuf *np;
    struct namebuf **npp, **nppend;
    struct timeval soon;

    dprintf(1, (ddt, "mark_cache()\n"));

    (void) gettime(&soon);
    soon.tv_sec += TIMBUF;

    npp = htp->h_tab;
    nppend = npp + htp->h_size;
    while (npp < nppend) {
        for (np = *npp++; np != NULL; np = np->n_next) {
            if (np->n_data == NULL)
                continue;
            for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
                if (dp->d_ttl < soon.tv_sec)
                    dp->d_ttl = ttl;
            }
        }
    }

    npp = htp->h_tab;
    nppend = npp + htp->h_size;
    while (npp < nppend) {
        for (np = *npp++; np != NULL; np = np->n_next) {
            if (np->n_hash == NULL)
                continue;
            mark_cache(np->n_hash, ttl);
        }
    }
}
#endif /* notdef */

/*
 * Dump current data base in a format similar to RFC 883.
 */

void
doadump()
{
	FILE	*fp;

	dprintf(3, (ddt, "doadump()\n"));

	if ((fp = fopen(dumpfile, "w")) == NULL)
		return;
	gettime(&tt);
	fprintf(fp, "; Dumped at %s", ctime(&tt.tv_sec));
#ifdef CRED
	fputs(
"; Note: Cr=(auth,answer,addtnl,cache) tag only shown for non-auth RR's\n",
	      fp);
#endif
	fputs(
"; Note: NT=milliseconds for any A RR which we've used as a nameserver\n",
	      fp);
	fprintf(fp, "; --- Cache & Data ---\n");
	if (hashtab != NULL)
		(void) db_dump(hashtab, fp, DB_Z_ALL, "");
	fprintf(fp, "; --- Hints ---\n");
	if (fcachetab != NULL)
		(void) db_dump(fcachetab, fp, DB_Z_ALL, "");
	(void) my_fclose(fp);
}

#ifdef ALLOW_UPDATES
/* Create a disk database to back up zones 
 */
void
zonedump(zp)
	register struct zoneinfo *zp;
{
	FILE		*fp;
	char		*fname;
	struct hashbuf	*htp;
	char		*op;
	struct stat	st;

	/* Only dump zone if there is a cache specified */
	if (zp->z_source && *(zp->z_source)) {
	    dprintf(1, (ddt, "zonedump(%s)\n", zp->z_source));

	    if ((fp = fopen(zp->z_source, "w")) == NULL)
		    return;
	    if (op = strchr(zp->z_origin, '.'))
		op++;
	    gettime(&tt);
	    htp = hashtab;
	    if (nlookup(zp->z_origin, &htp, &fname, 0) != NULL) {
		    db_dump(htp, fp, zp-zones, (op == NULL ? "" : op));
		    zp->z_state &= ~Z_CHANGED;		/* Checkpointed */
	    }
	    (void) my_fclose(fp);
	    if (stat(zp->z_source, &st) == 0)
		    zp->z_ftime = st.st_mtime;
	} else {
	    dprintf(1, (ddt, "zonedump: no zone to dump\n"));
	}
}
#endif

int
db_dump(htp, fp, zone, origin)
	int zone;
	struct hashbuf *htp;
	FILE *fp;
	char *origin;
{
	register struct databuf *dp;
	register struct namebuf *np;
	struct namebuf **npp, **nppend;
	char dname[MAXDNAME];
	u_int32_t n;
	u_int32_t addr;
	int j, i;
	register u_char *cp;
	u_char *end;
	char *proto, *sep;
	int found_data, tab, printed_origin = 0;

	npp = htp->h_tab;
	nppend = npp + htp->h_size;
	while (npp < nppend) {
	    for (np = *npp++; np != NULL; np = np->n_next) {
		if (np->n_data == NULL)
			continue;
		/* Blecch - can't tell if there is data here for the
		 * right zone, so can't print name yet
		 */
		found_data = 0;
		/* we want a snapshot in time... */
		for (dp = np->n_data; dp != NULL; dp = dp->d_next) {
			/* Is the data for this zone? */
			if (zone != DB_Z_ALL && dp->d_zone != zone)
			    continue;
			if (dp->d_zone == DB_Z_CACHE &&
			    dp->d_ttl <= tt.tv_sec &&
			    (dp->d_flags & DB_F_HINT) == 0)
				continue;
			if (!printed_origin) {
			    fprintf(fp, "$ORIGIN %s.\n", origin);
			    printed_origin++;
			}
			tab = 0;
#ifdef NCACHE
			if (dp->d_rcode == NXDOMAIN ||
			    dp->d_rcode == NOERROR_NODATA) {
				fputc(';', fp);
			}
#endif /*NCACHE*/
			if (!found_data) {
			    if (np->n_dname[0] == 0) {
				if (origin[0] == 0)
				    fprintf(fp, ".\t");
				else
				    fprintf(fp, ".%s.\t", origin); /* ??? */
			    } else
				fprintf(fp, "%s\t", np->n_dname);
			    if (strlen(np->n_dname) < 8)
				tab = 1;
			    found_data++;
			} else {
			    (void) putc('\t', fp);
			    tab = 1;
			}
			if (dp->d_zone == DB_Z_CACHE) {
			    if (dp->d_flags & DB_F_HINT
				&& (int32_t)(dp->d_ttl - tt.tv_sec)
				    < DB_ROOT_TIMBUF)
				    fprintf(fp, "%d\t", DB_ROOT_TIMBUF);
			    else
				    fprintf(fp, "%d\t",
				        (int)(dp->d_ttl - tt.tv_sec));
			} else if (dp->d_ttl != 0 &&
			    dp->d_ttl != zones[dp->d_zone].z_minimum)
				fprintf(fp, "%d\t", (int)dp->d_ttl);
			else if (tab)
			    (void) putc('\t', fp);
			fprintf(fp, "%s\t%s\t",
				p_class(dp->d_class),
				p_type(dp->d_type));
			cp = (u_char *)dp->d_data;
			sep = "\t;";
#ifdef NCACHE
			if (dp->d_rcode == NXDOMAIN ||
			    dp->d_rcode == NOERROR_NODATA) {
				fprintf(fp, "%s%s-$",
					(dp->d_rcode == NXDOMAIN)
						?"NXDOMAIN" :"NODATA",
					sep);
				goto eoln;
			}
#endif
			/*
			 * Print type specific data
			 */
			switch (dp->d_type) {
			case T_A:
				switch (dp->d_class) {
				case C_IN:
				case C_HS:
					GETLONG(n, cp);
					n = htonl(n);
					fprintf(fp, "%s",
					   inet_ntoa(*(struct in_addr *)&n));
					break;
				}
				if (dp->d_nstime) {
					fprintf(fp, "%sNT=%d",
						sep, dp->d_nstime);
					sep = " ";
				}
				break;
			case T_CNAME:
			case T_MB:
			case T_MG:
			case T_MR:
			case T_PTR:
				fprintf(fp, "%s.", cp);
				break;