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
createmf(uid,file)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
accessmf(path)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