1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 1995 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include "mail.h" 33 /* 34 If mail file does not exist create it 35 */ 36 #ifdef OLD 37 void createmf(uid, file) 38 uid_t uid; 39 char *file; 40 { 41 int fd; 42 43 void (*istat)(), (*qstat)(), (*hstat)(); 44 45 if (access(file, A_EXIST) == CERROR) { 46 istat = signal(SIGINT, SIG_IGN); 47 qstat = signal(SIGQUIT, SIG_IGN); 48 hstat = signal(SIGHUP, SIG_IGN); 49 umask(0); 50 if ((fd = creat(file, MFMODE)) == -1) 51 sav_errno = errno; 52 else 53 close(fd); 54 umask(7); 55 (void) signal(SIGINT, istat); 56 (void) signal(SIGQUIT, qstat); 57 (void) signal(SIGHUP, hstat); 58 } 59 } 60 #else 61 62 #include <sys/stat.h> 63 #include <fcntl.h> 64 #include <stdio.h> 65 66 int accessmf(path) 67 char *path; 68 { 69 70 struct stat fsb,sb; 71 int mbfd; 72 tryagain: 73 if (lstat(path, &sb)) { 74 /* file/symlink does not exist, so create one */ 75 mbfd = open(path, 76 O_APPEND|O_CREAT|O_EXCL|O_WRONLY, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP); 77 chmod(path, 0660); 78 /* if someone create a symlink/file just ahead */ 79 /* of us, the create will failed with EEXIST */ 80 /* This is what we want, because we do not */ 81 /* want someone to re-direct our "create" */ 82 /* request to a another location. */ 83 if (mbfd == -1) { 84 if (errno == EEXIST) 85 goto tryagain; 86 } 87 88 /* file/symlink exist, make sure it is not linked */ 89 } else if (sb.st_nlink != 1 || S_ISLNK(sb.st_mode)) { 90 fprintf(stderr, 91 "%s: security violation, '%s' should not be linked to other file\n", program, path); 92 sav_errno = errno; 93 return -1; 94 } else { 95 /* if we get here, there is a pre-existing file, */ 96 /* and it is not a symlink... */ 97 /* open it, and make sure it is the same file */ 98 /* we lstat() before... */ 99 /* this is to guard against someone deleting the */ 100 /* old file and creat a new symlink in its place */ 101 /* We are not createing a new file here, but we */ 102 /* do not want append to the worng file either */ 103 mbfd = open(path, O_APPEND|O_WRONLY, 0); 104 if (mbfd != -1 && 105 (fstat(mbfd, &fsb) || fsb.st_nlink != 1 || 106 S_ISLNK(fsb.st_mode) || sb.st_dev != fsb.st_dev || 107 sb.st_ino != fsb.st_ino)) { 108 /* file changed after open */ 109 fprintf(stderr, "%s: security violation, '%s' inode changed after open\n", program, path); 110 (void)close(mbfd); 111 return -1; 112 } 113 } 114 115 if (mbfd == -1) { 116 sav_errno = errno; 117 return -1; 118 } 119 120 return mbfd; 121 } 122 #endif 123