break out special local mail processing (e.g., mapping to the

[unix-history] / usr / src / usr.sbin / kvm_mkdb / testdb.c

/*-
* Copyright (c) 1992, 1993
*      The Regents of the University of California.  All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)testdb.c    8.1 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#include <sys/file.h>
#include <errno.h>
#include <limits.h>
#include <kvm.h>
#include <db.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <paths.h>

#include "extern.h"

/* Return true if the db file is valid, else false */
int
testdb()
{
       register DB *db;
       register int cc, kd, ret, dbversionlen;
       register char *cp, *uf;
       DBT rec;
       struct nlist nitem;
       char dbname[MAXPATHLEN], dbversion[_POSIX2_LINE_MAX];
       char kversion[_POSIX2_LINE_MAX];

       ret = 0;
       db = NULL;

       if ((kd = open(_PATH_KMEM, O_RDONLY, 0)) < 0)
               goto close;

       uf = _PATH_UNIX;
       if ((cp = rindex(uf, '/')) != 0)
               uf = cp + 1;
       (void) snprintf(dbname, sizeof(dbname), "%skvm_%s.db", _PATH_VARDB, uf);
       if ((db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL)) == NULL)
               goto close;

       /* Read the version out of the database */
       rec.data = VRS_KEY;
       rec.size = sizeof(VRS_KEY) - 1;
       if ((db->get)(db, &rec, &rec, 0))
               goto close;
       if (rec.data == 0 || rec.size > sizeof(dbversion))
               goto close;
       bcopy(rec.data, dbversion, rec.size);
       dbversionlen = rec.size;

       /* Read version string from kernel memory */
       rec.data = VRS_SYM;
       rec.size = sizeof(VRS_SYM) - 1;
       if ((db->get)(db, &rec, &rec, 0))
               goto close;
       if (rec.data == 0 || rec.size != sizeof(struct nlist))
               goto close;
       bcopy(rec.data, &nitem, sizeof(nitem));
       /*
        * Theoretically possible for lseek to be seeking to -1.  Not
        * that it's something to lie awake nights about, however.
        */
       errno = 0;
       if (lseek(kd, (off_t)nitem.n_value, SEEK_SET) == -1 && errno != 0)
               goto close;
       cc = read(kd, kversion, sizeof(kversion));
       if (cc < 0 || cc != sizeof(kversion))
               goto close;

       /* If they match, we win */
       ret = bcmp(dbversion, kversion, dbversionlen) == 0;

close:  if (kd >= 0)
               (void)close(kd);
       if (db)
               (void)(db->close)(db);
       return (ret);
}