db_vrfy.c

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	switch (pip->type) {
	case P_IBTREE:
	case P_LDUP:
		if (!LF_ISSET(ST_DUPSORT)) {
			EPRINT((dbenv,
	    "Page %lu: sorted duplicate set in unsorted-dup database",
			    (u_long)pgno));
			isbad = 1;
		}
		break;
	case P_IRECNO:
	case P_LRECNO:
		if (LF_ISSET(ST_DUPSORT)) {
			EPRINT((dbenv,
	    "Page %lu: unsorted duplicate set in sorted-dup database",
			    (u_long)pgno));
			isbad = 1;
		}
		break;
	default:
		/*
		 * If the page is entirely zeroed, its pip->type will be a lie
		 * (we assumed it was a hash page, as they're allowed to be
		 * zeroed);  handle this case specially.
		 */
		if (F_ISSET(pip, VRFY_IS_ALLZEROES))
			ZEROPG_ERR_PRINT(dbenv, pgno, "duplicate page");
		else
			EPRINT((dbenv,
		    "Page %lu: duplicate page of inappropriate type %lu",
			    (u_long)pgno, (u_long)pip->type));
		isbad = 1;
		break;
	}

	if ((ret = __db_vrfy_putpageinfo(dbenv, vdp, pip)) != 0)
		return (ret);
	return (isbad == 1 ? DB_VERIFY_BAD : 0);
}

/*
 * __db_salvage_duptree --
 *	Attempt to salvage a given duplicate tree, given its alleged root.
 *
 *	The key that corresponds to this dup set has been passed to us
 *	in DBT *key.  Because data items follow keys, though, it has been
 *	printed once already.
 *
 *	The basic idea here is that pgno ought to be a P_LDUP, a P_LRECNO, a
 *	P_IBTREE, or a P_IRECNO.  If it's an internal page, use the verifier
 *	functions to make sure it's safe;  if it's not, we simply bail and the
 *	data will have to be printed with no key later on.  if it is safe,
 *	recurse on each of its children.
 *
 *	Whether or not it's safe, if it's a leaf page, __bam_salvage it.
 *
 *	At all times, use the DB hanging off vdp to mark and check what we've
 *	done, so each page gets printed exactly once and we don't get caught
 *	in any cycles.
 *
 * PUBLIC: int __db_salvage_duptree __P((DB *, VRFY_DBINFO *, db_pgno_t,
 * PUBLIC:     DBT *, void *, int (*)(void *, const void *), u_int32_t));
 */
int
__db_salvage_duptree(dbp, vdp, pgno, key, handle, callback, flags)
	DB *dbp;
	VRFY_DBINFO *vdp;
	db_pgno_t pgno;
	DBT *key;
	void *handle;
	int (*callback) __P((void *, const void *));
	u_int32_t flags;
{
	DB_MPOOLFILE *mpf;
	PAGE *h;
	int ret, t_ret;

	mpf = dbp->mpf;

	if (pgno == PGNO_INVALID || !IS_VALID_PGNO(pgno))
		return (DB_VERIFY_BAD);

	/* We have a plausible page.  Try it. */
	if ((ret = mpf->get(mpf, &pgno, 0, &h)) != 0)
		return (ret);

	switch (TYPE(h)) {
	case P_IBTREE:
	case P_IRECNO:
		if ((ret = __db_vrfy_common(dbp, vdp, h, pgno, flags)) != 0)
			goto err;
		if ((ret = __bam_vrfy(dbp,
		    vdp, h, pgno, flags | DB_NOORDERCHK)) != 0 ||
		    (ret = __db_salvage_markdone(vdp, pgno)) != 0)
			goto err;
		/*
		 * We have a known-healthy internal page.  Walk it.
		 */
		if ((ret = __bam_salvage_walkdupint(dbp, vdp, h, key,
		    handle, callback, flags)) != 0)
			goto err;
		break;
	case P_LRECNO:
	case P_LDUP:
		if ((ret = __bam_salvage(dbp,
		    vdp, pgno, TYPE(h), h, handle, callback, key, flags)) != 0)
			goto err;
		break;
	default:
		ret = DB_VERIFY_BAD;
		goto err;
		/* NOTREACHED */
	}

err:	if ((t_ret = mpf->put(mpf, h, 0)) != 0 && ret == 0)
		ret = t_ret;
	return (ret);
}

/*
 * __db_salvage_subdbs --
 *	Check and see if this database has subdbs;  if so, try to salvage
 *	them independently.
 */
static int
__db_salvage_subdbs(dbp, vdp, handle, callback, flags, hassubsp)
	DB *dbp;
	VRFY_DBINFO *vdp;
	void *handle;
	int (*callback) __P((void *, const void *));
	u_int32_t flags;
	int *hassubsp;
{
	BTMETA *btmeta;
	DB *pgset;
	DBC *pgsc;
	DB_MPOOLFILE *mpf;
	PAGE *h;
	db_pgno_t p, meta_pgno;
	int ret, err_ret;

	pgset = NULL;
	pgsc = NULL;
	mpf = dbp->mpf;
	err_ret = 0;

	meta_pgno = PGNO_BASE_MD;
	if ((ret = mpf->get(mpf, &meta_pgno, 0, &h)) != 0)
		return (ret);

	if (TYPE(h) == P_BTREEMETA)
		btmeta = (BTMETA *)h;
	else {
		/* Not a btree metadata, ergo no subdbs, so just return. */
		ret = 0;
		goto err;
	}

	/* If it's not a safe page, bail on the attempt. */
	if ((ret = __db_vrfy_common(dbp, vdp, h, PGNO_BASE_MD, flags)) != 0 ||
	   (ret = __bam_vrfy_meta(dbp, vdp, btmeta, PGNO_BASE_MD, flags)) != 0)
		goto err;

	if (!F_ISSET(&btmeta->dbmeta, BTM_SUBDB)) {
		/* No subdbs, just return. */
		ret = 0;
		goto err;
	}

	/* We think we've got subdbs.  Mark it so. */
	*hassubsp = 1;

	if ((ret = mpf->put(mpf, h, 0)) != 0)
		return (ret);

	/*
	 * We have subdbs.  Try to crack them.
	 *
	 * To do so, get a set of leaf pages in the master
	 * database, and then walk each of the valid ones, salvaging
	 * subdbs as we go.  If any prove invalid, just drop them;  we'll
	 * pick them up on a later pass.
	 */
	if ((ret = __db_vrfy_pgset(dbp->dbenv, dbp->pgsize, &pgset)) != 0)
		return (ret);
	if ((ret =
	    __db_meta2pgset(dbp, vdp, PGNO_BASE_MD, flags, pgset)) != 0)
		goto err;

	if ((ret = pgset->cursor(pgset, NULL, &pgsc, 0)) != 0)
		goto err;
	while ((ret = __db_vrfy_pgset_next(pgsc, &p)) == 0) {
		if ((ret = mpf->get(mpf, &p, 0, &h)) != 0) {
			err_ret = ret;
			continue;
		}
		if ((ret = __db_vrfy_common(dbp, vdp, h, p, flags)) != 0 ||
		    (ret = __bam_vrfy(dbp,
		    vdp, h, p, flags | DB_NOORDERCHK)) != 0)
			goto nextpg;
		if (TYPE(h) != P_LBTREE)
			goto nextpg;
		else if ((ret = __db_salvage_subdbpg(
		    dbp, vdp, h, handle, callback, flags)) != 0)
			err_ret = ret;
nextpg:		if ((ret = mpf->put(mpf, h, 0)) != 0)
			err_ret = ret;
	}

	if (ret != DB_NOTFOUND)
		goto err;
	if ((ret = pgsc->c_close(pgsc)) != 0)
		goto err;

	ret = pgset->close(pgset, 0);
	return ((ret == 0 && err_ret != 0) ? err_ret : ret);

	/* NOTREACHED */

err:	if (pgsc != NULL)
		(void)pgsc->c_close(pgsc);
	if (pgset != NULL)
		(void)pgset->close(pgset, 0);
	(void)mpf->put(mpf, h, 0);
	return (ret);
}

/*
 * __db_salvage_subdbpg --
 *	Given a known-good leaf page in the master database, salvage all
 *	leaf pages corresponding to each subdb.
 */
static int
__db_salvage_subdbpg(dbp, vdp, master, handle, callback, flags)
	DB *dbp;
	VRFY_DBINFO *vdp;
	PAGE *master;
	void *handle;
	int (*callback) __P((void *, const void *));
	u_int32_t flags;
{
	BKEYDATA *bkkey, *bkdata;
	BOVERFLOW *bo;
	DB *pgset;
	DBC *pgsc;
	DBT key;
	DB_ENV *dbenv;
	DB_MPOOLFILE *mpf;
	PAGE *subpg;
	db_indx_t i;
	db_pgno_t meta_pgno, p;
	int ret, err_ret, t_ret;
	char *subdbname;

	dbenv = dbp->dbenv;
	mpf = dbp->mpf;
	ret = err_ret = 0;
	subdbname = NULL;

	if ((ret = __db_vrfy_pgset(dbenv, dbp->pgsize, &pgset)) != 0)
		return (ret);

	/*
	 * For each entry, get and salvage the set of pages
	 * corresponding to that entry.
	 */
	for (i = 0; i < NUM_ENT(master); i += P_INDX) {
		bkkey = GET_BKEYDATA(dbp, master, i);
		bkdata = GET_BKEYDATA(dbp, master, i + O_INDX);

		/* Get the subdatabase name. */
		if (B_TYPE(bkkey->type) == B_OVERFLOW) {
			/*
			 * We can, in principle anyway, have a subdb
			 * name so long it overflows.  Ick.
			 */
			bo = (BOVERFLOW *)bkkey;
			if ((ret = __db_safe_goff(dbp, vdp, bo->pgno, &key,
			    (void **)&subdbname, flags)) != 0) {
				err_ret = DB_VERIFY_BAD;
				continue;
			}

			/* Nul-terminate it. */
			if ((ret = __os_realloc(dbenv,
			    key.size + 1, &subdbname)) != 0)
				goto err;
			subdbname[key.size] = '\0';
		} else if (B_TYPE(bkkey->type == B_KEYDATA)) {
			if ((ret = __os_realloc(dbenv,
			    bkkey->len + 1, &subdbname)) != 0)
				goto err;
			memcpy(subdbname, bkkey->data, bkkey->len);
			subdbname[bkkey->len] = '\0';
		}

		/* Get the corresponding pgno. */
		if (bkdata->len != sizeof(db_pgno_t)) {
			err_ret = DB_VERIFY_BAD;
			continue;
		}
		memcpy(&meta_pgno, bkdata->data, sizeof(db_pgno_t));

		/*
		 * Subdatabase meta pgnos are stored in network byte
		 * order for cross-endian compatibility.  Swap if appropriate.
		 */
		DB_NTOHL(&meta_pgno);

		/* If we can't get the subdb meta page, just skip the subdb. */
		if (!IS_VALID_PGNO(meta_pgno) ||
		    (ret = mpf->get(mpf, &meta_pgno, 0, &subpg)) != 0) {
			err_ret = ret;
			continue;
		}

		/*
		 * Verify the subdatabase meta page.  This has two functions.
		 * First, if it's bad, we have no choice but to skip the subdb
		 * and let the pages just get printed on a later pass.  Second,
		 * the access-method-specific meta verification routines record
		 * the various state info (such as the presence of dups)
		 * that we need for __db_prheader().
		 */
		if ((ret =
		    __db_vrfy_common(dbp, vdp, subpg, meta_pgno, flags)) != 0) {
			err_ret = ret;
			(void)mpf->put(mpf, subpg, 0);
			continue;
		}
		switch (TYPE(subpg)) {
		case P_BTREEMETA:
			if ((ret = __bam_vrfy_meta(dbp,
			    vdp, (BTMETA *)subpg, meta_pgno, flags)) != 0) {
				err_ret = ret;
				(void)mpf->put(mpf, subpg, 0);
				continue;
			}
			break;
		case P_HASHMETA:
			if ((ret = __ham_vrfy_meta(dbp,
			    vdp, (HMETA *)subpg, meta_pgno, flags)) != 0) {
				err_ret = ret;
				(void)mpf->put(mpf, subpg, 0);
				continue;
			}
			break;
		default:
			/* This isn't an appropriate page;  skip this subdb. */
			err_ret = DB_VERIFY_BAD;
			continue;
			/* NOTREACHED */
		}

		if ((ret = mpf->put(mpf, subpg, 0)) != 0) {
			err_ret = ret;
			continue;
		}

		/* Print a subdatabase header. */
		if ((ret = __db_prheader(dbp,
		    subdbname, 0, 0, handle, callback, vdp, meta_pgno)) != 0)
			goto err;

		if ((ret = __db_meta2pgset(dbp, vdp, meta_pgno,
		    flags, pgset)) != 0) {
			err_ret = ret;
			continue;
		}

		if ((ret = pgset->cursor(pgset, NULL, &pgsc, 0)) != 0)
			goto err;
		while ((ret = __db_vrfy_pgset_next(pgsc, &p)) == 0) {
			if ((ret = mpf->get(mpf, &p, 0, &subpg)) != 0) {
				err_ret = ret;
				continue;
			}
			if ((ret = __db_salvage(dbp, vdp, p, subpg,
			    handle, callback, flags)) != 0)
				err_ret = ret;
			if ((ret = mpf->put(mpf, subpg, 0)) != 0)
				err_ret = ret;
		}

		if (ret != DB_NOTFOUND)
			goto err;

		if ((ret = pgsc->c_close(pgsc)) != 0)
			goto err;
		if ((ret = __db_prfooter(handle, callback)) != 0)
			goto err;
	}
err:	if (subdbname)
		__os_free(dbenv, subdbname);

	if ((t_ret = pgset->close(pgset, 0)) != 0)
		ret = t_ret;

	if ((t_ret = __db_salvage_markdone(vdp, PGNO(master))) != 0)
		return (t_ret);

	return ((err_ret != 0) ? err_ret : ret);
}

/*
 * __db_meta2pgset --
 *	Given a known-safe meta page number, return the set of pages
 *	corresponding to the database it represents.  Return DB_VERIFY_BAD if
 *	it's not a suitable meta page or is invalid.
 */
static int
__db_meta2pgset(dbp, vdp, pgno, flags, pgset)
	DB *dbp;
	VRFY_DBINFO *vdp;
	db_pgno_t pgno;
	u_int32_t flags;
	DB *pgset;
{
	DB_MPOOLFILE *mpf;
	PAGE *h;
	int ret, t_ret;

	mpf = dbp->mpf;

	if ((ret = mpf->get(mpf, &pgno, 0, &h)) != 0)
		return (ret);

	switch (TYPE(h)) {
	case P_BTREEMETA:
		ret = __bam_meta2pgset(dbp, vdp, (BTMETA *)h, flags, pgset);
		break;
	case P_HASHMETA:
		ret = __ham_meta2pgset(dbp, vdp, (HMETA *)h, flags, pgset);
		break;
	default:
		ret = DB_VERIFY_BAD;
		break;
	}

	if ((t_ret = mpf->put(mpf, h, 0)) != 0)
		return (t_ret);
	return (ret);
}

/*
 * __db_guesspgsize --
 *	Try to guess what the pagesize is if the one on the meta page
 *	and the one in the db are invalid.
 */
static int
__db_guesspgsize(dbenv, fhp)
	DB_ENV *dbenv;
	DB_FH *fhp;
{
	db_pgno_t i;
	size_t nr;
	u_int32_t guess;
	u_int8_t type;

	for (guess = DB_MAX_PGSIZE; guess >= DB_MIN_PGSIZE; guess >>= 1) {
		/*
		 * We try to read three pages ahead after the first one
		 * and make sure we have plausible types for all of them.
		 * If the seeks fail, continue with a smaller size;
		 * we're probably just looking past the end of the database.
		 * If they succeed and the types are reasonable, also continue
		 * with a size smaller;  we may be looking at pages N,
		 * 2N, and 3N for some N > 1.
		 *
		 * As soon as we hit an invalid type, we stop and return
		 * our previous guess; that last one was probably the page size.
		 */
		for (i = 1; i <= 3; i++) {
			if (__os_seek(dbenv, fhp, guess,
			    i, SSZ(DBMETA, type), 0, DB_OS_SEEK_SET) != 0)
				break;
			if (__os_read(dbenv,
			    fhp, &type, 1, &nr) != 0 || nr == 0)
				break;
			if (type == P_INVALID || type >= P_PAGETYPE_MAX)
				return (guess << 1);
		}
	}

	/*
	 * If we're just totally confused--the corruption takes up most of the
	 * beginning pages of the database--go with the default size.
	 */
	return (DB_DEF_IOSIZE);
}