1 /* $NetBSD: checkmount_default.c,v 1.1.1.3 2015/01/17 16:34:16 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1997-2014 Erez Zadok 5 * Copyright (c) 1990 Jan-Simon Pendry 6 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine 7 * Copyright (c) 1990 The Regents of the University of California. 8 * All rights reserved. 9 * 10 * This code is derived from software contributed to Berkeley by 11 * Jan-Simon Pendry at Imperial College, London. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * 38 * File: am-utils/conf/checkmount/checkmount_default.c 39 * 40 */ 41 42 #ifdef HAVE_CONFIG_H 43 # include <config.h> 44 #endif /* HAVE_CONFIG_H */ 45 #include <am_defs.h> 46 47 #ifndef _PATH_MTAB 48 #define _PATH_MTAB "/etc/mtab" 49 #endif /* not _PATH_MTAB */ 50 51 extern int is_same_host(char *name1, char *name2, struct in_addr addr2); 52 53 54 int 55 fixmount_check_mount(char *host, struct in_addr hostaddr, char *path) 56 { 57 FILE *mtab; 58 mntent_t *ment; 59 int found = 0; 60 61 /* scan mtab for path */ 62 if (!(mtab = setmntent(_PATH_MTAB, "r"))) { 63 perror(_PATH_MTAB); 64 exit(1); 65 } 66 67 /* 68 * setmntent() doesn't do locking in read-only mode. Too bad -- it seems to 69 * rely on mount() and friends to do atomic updates by renaming the file. 70 * Well, our patched amd rewrites mtab in place to avoid NFS lossage, so 71 * better do the locking ourselves. 72 */ 73 #ifdef HAVE_FLOCK 74 if (flock(fileno(mtab), LOCK_SH) < 0) { 75 #else /* not HAVE_FLOCK */ 76 if (lockf(fileno(mtab), F_LOCK, 0) < 0) { 77 #endif /* not HAVE_FLOCK */ 78 perror(_PATH_MTAB); 79 exit(1); 80 } 81 82 while (!found && (ment = getmntent(mtab))) { 83 char *colon; 84 85 if ((colon = strchr(ment->mnt_fsname, ':'))) { 86 *colon = '\0'; 87 if ((STREQ(colon + 1, path) || 88 STREQ(ment->mnt_dir, path)) && 89 is_same_host(ment->mnt_fsname, host, hostaddr)) 90 found = 1; 91 } 92 } 93 94 (void) endmntent(mtab); 95 96 if (!found) { 97 char *swap; 98 99 /* swap files never show up in mtab, only root fs */ 100 if ((swap = strstr(path, "swap"))) { 101 strncpy(swap, "root", 4); /* this should NOT use xstrlcpy */ 102 found = fixmount_check_mount(host, hostaddr, path); 103 strncpy(swap, "swap", 4); /* this should NOT use xstrlcpy */ 104 } 105 } 106 return found; 107 } 108