1 /* $OpenBSD: testdb.c,v 1.7 2004/11/24 17:57:16 millert Exp $ */ 2 3 /*- 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #ifndef lint 33 #if 0 34 static char sccsid[] = "from: @(#)testdb.c 8.1 (Berkeley) 6/6/93"; 35 #else 36 static char *rcsid = "$OpenBSD: testdb.c,v 1.7 2004/11/24 17:57:16 millert Exp $"; 37 #endif 38 #endif /* not lint */ 39 40 #include <sys/param.h> 41 #include <sys/sysctl.h> 42 43 #include <db.h> 44 #include <fcntl.h> 45 #include <kvm.h> 46 #include <limits.h> 47 #include <paths.h> 48 #include <stdio.h> 49 #include <string.h> 50 #include <unistd.h> 51 52 #include "extern.h" 53 54 /* Return true if the db file is valid, else false */ 55 int 56 testdb(char *dbname) 57 { 58 DBT rec; 59 DB *db = NULL; 60 size_t kversionlen; 61 char kversion[LINE_MAX]; 62 int mib[2], ret = 0; 63 64 /* Read version string of running kernel */ 65 mib[0] = CTL_KERN; 66 mib[1] = KERN_VERSION; 67 kversionlen = sizeof(kversion); 68 if (sysctl(mib, 2, kversion, &kversionlen, NULL, 0) < 0) 69 goto close; 70 71 /* Read the version out of the database */ 72 if ((db = dbopen(dbname, O_RDONLY, 0, DB_HASH, NULL)) == NULL) 73 goto close; 74 rec.data = VRS_KEY; 75 rec.size = sizeof(VRS_KEY) - 1; 76 if ((db->get)(db, &rec, &rec, 0)) 77 goto close; 78 if (rec.data == NULL || rec.size > kversionlen) 79 goto close; 80 81 /* If they match, we win */ 82 ret = memcmp(kversion, rec.data, rec.size) == 0; 83 84 close: 85 if (db) 86 (void)(db->close)(db); 87 return (ret); 88 } 89