1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 /*static char sccsid[] = "from: @(#)testdb.c 8.1 (Berkeley) 6/6/93";*/ 36 static char *rcsid = "$Id: testdb.c,v 1.2 1994/06/11 07:57:42 mycroft Exp $"; 37 #endif /* not lint */ 38 39 #include <sys/param.h> 40 #include <sys/file.h> 41 #include <errno.h> 42 #include <limits.h> 43 #include <kvm.h> 44 #include <db.h> 45 #include <stdio.h> 46 #include <unistd.h> 47 #include <string.h> 48 #include <paths.h> 49 50 #include "extern.h" 51 52 /* Return true if the db file is valid, else false */ 53 int 54 testdb() 55 { 56 register DB *db; 57 register int cc, kd, ret, dbversionlen; 58 register char *cp, *uf; 59 DBT rec; 60 struct nlist nitem; 61 char dbname[MAXPATHLEN], dbversion[_POSIX2_LINE_MAX]; 62 char kversion[_POSIX2_LINE_MAX]; 63 64 ret = 0; 65 db = NULL; 66 67 if ((kd = open(_PATH_KMEM, O_RDONLY, 0)) < 0) 68 goto close; 69 70 uf = _PATH_UNIX; 71 if ((cp = rindex(uf, '/')) != 0) 72 uf = cp + 1; 73 (void) snprintf(dbname, sizeof(dbname), "%skvm_%s.db", _PATH_VARDB, uf); 74 if ((db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL)) == NULL) 75 goto close; 76 77 /* Read the version out of the database */ 78 rec.data = VRS_KEY; 79 rec.size = sizeof(VRS_KEY) - 1; 80 if ((db->get)(db, &rec, &rec, 0)) 81 goto close; 82 if (rec.data == 0 || rec.size > sizeof(dbversion)) 83 goto close; 84 bcopy(rec.data, dbversion, rec.size); 85 dbversionlen = rec.size; 86 87 /* Read version string from kernel memory */ 88 rec.data = VRS_SYM; 89 rec.size = sizeof(VRS_SYM) - 1; 90 if ((db->get)(db, &rec, &rec, 0)) 91 goto close; 92 if (rec.data == 0 || rec.size != sizeof(struct nlist)) 93 goto close; 94 bcopy(rec.data, &nitem, sizeof(nitem)); 95 /* 96 * Theoretically possible for lseek to be seeking to -1. Not 97 * that it's something to lie awake nights about, however. 98 */ 99 errno = 0; 100 if (lseek(kd, (off_t)nitem.n_value, SEEK_SET) == -1 && errno != 0) 101 goto close; 102 cc = read(kd, kversion, sizeof(kversion)); 103 if (cc < 0 || cc != sizeof(kversion)) 104 goto close; 105 106 /* If they match, we win */ 107 ret = bcmp(dbversion, kversion, dbversionlen) == 0; 108 109 close: if (kd >= 0) 110 (void)close(kd); 111 if (db) 112 (void)(db->close)(db); 113 return (ret); 114 } 115