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 #include "mail.h" 31 /* 32 If mail file does not exist create it 33 */ 34 #ifdef OLD 35 void createmf(uid, file) 36 uid_t uid; 37 char *file; 38 { 39 int fd; 40 41 void (*istat)(), (*qstat)(), (*hstat)(); 42 43 if (access(file, A_EXIST) == CERROR) { 44 istat = signal(SIGINT, SIG_IGN); 45 qstat = signal(SIGQUIT, SIG_IGN); 46 hstat = signal(SIGHUP, SIG_IGN); 47 umask(0); 48 if ((fd = creat(file, MFMODE)) == -1) 49 sav_errno = errno; 50 else 51 close(fd); 52 umask(7); 53 (void) signal(SIGINT, istat); 54 (void) signal(SIGQUIT, qstat); 55 (void) signal(SIGHUP, hstat); 56 } 57 } 58 #else 59 60 #include <sys/stat.h> 61 #include <fcntl.h> 62 #include <stdio.h> 63 64 int accessmf(path) 65 char *path; 66 { 67 68 struct stat fsb,sb; 69 int mbfd; 70 tryagain: 71 if (lstat(path, &sb)) { 72 /* file/symlink does not exist, so create one */ 73 mbfd = open(path, 74 O_APPEND|O_CREAT|O_EXCL|O_WRONLY, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP); 75 chmod(path, 0660); 76 /* if someone create a symlink/file just ahead */ 77 /* of us, the create will failed with EEXIST */ 78 /* This is what we want, because we do not */ 79 /* want someone to re-direct our "create" */ 80 /* request to a another location. */ 81 if (mbfd == -1) { 82 if (errno == EEXIST) 83 goto tryagain; 84 } 85 86 /* file/symlink exist, make sure it is not linked */ 87 } else if (sb.st_nlink != 1 || S_ISLNK(sb.st_mode)) { 88 fprintf(stderr, 89 "%s: security violation, '%s' should not be linked to other file\n", program, path); 90 sav_errno = errno; 91 return -1; 92 } else { 93 /* if we get here, there is a pre-existing file, */ 94 /* and it is not a symlink... */ 95 /* open it, and make sure it is the same file */ 96 /* we lstat() before... */ 97 /* this is to guard against someone deleting the */ 98 /* old file and creat a new symlink in its place */ 99 /* We are not createing a new file here, but we */ 100 /* do not want append to the worng file either */ 101 mbfd = open(path, O_APPEND|O_WRONLY, 0); 102 if (mbfd != -1 && 103 (fstat(mbfd, &fsb) || fsb.st_nlink != 1 || 104 S_ISLNK(fsb.st_mode) || sb.st_dev != fsb.st_dev || 105 sb.st_ino != fsb.st_ino)) { 106 /* file changed after open */ 107 fprintf(stderr, "%s: security violation, '%s' inode changed after open\n", program, path); 108 (void)close(mbfd); 109 return -1; 110 } 111 } 112 113 if (mbfd == -1) { 114 sav_errno = errno; 115 return -1; 116 } 117 118 return mbfd; 119 } 120 #endif 121