xref: /illumos-gate/usr/src/cmd/mail/createmf.c (revision 7c478bd9)
1*7c478bd9Sstevel@tonic-gate /*
2*7c478bd9Sstevel@tonic-gate  * CDDL HEADER START
3*7c478bd9Sstevel@tonic-gate  *
4*7c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*7c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*7c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*7c478bd9Sstevel@tonic-gate  * with the License.
8*7c478bd9Sstevel@tonic-gate  *
9*7c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*7c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*7c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*7c478bd9Sstevel@tonic-gate  * and limitations under the License.
13*7c478bd9Sstevel@tonic-gate  *
14*7c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*7c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*7c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*7c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*7c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*7c478bd9Sstevel@tonic-gate  *
20*7c478bd9Sstevel@tonic-gate  * CDDL HEADER END
21*7c478bd9Sstevel@tonic-gate  */
22*7c478bd9Sstevel@tonic-gate /*
23*7c478bd9Sstevel@tonic-gate  * Copyright 1995 Sun Microsystems, Inc.  All rights reserved.
24*7c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
25*7c478bd9Sstevel@tonic-gate  */
27*7c478bd9Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28*7c478bd9Sstevel@tonic-gate /*	  All Rights Reserved  	*/
30*7c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
32*7c478bd9Sstevel@tonic-gate #include "mail.h"
33*7c478bd9Sstevel@tonic-gate /*
34*7c478bd9Sstevel@tonic-gate 	If mail file does not exist create it
35*7c478bd9Sstevel@tonic-gate */
36*7c478bd9Sstevel@tonic-gate #ifdef OLD
createmf(uid,file)37*7c478bd9Sstevel@tonic-gate void createmf(uid, file)
38*7c478bd9Sstevel@tonic-gate uid_t uid;
39*7c478bd9Sstevel@tonic-gate char *file;
40*7c478bd9Sstevel@tonic-gate {
41*7c478bd9Sstevel@tonic-gate 	int fd;
43*7c478bd9Sstevel@tonic-gate 	void (*istat)(), (*qstat)(), (*hstat)();
45*7c478bd9Sstevel@tonic-gate 	if (access(file, A_EXIST) == CERROR) {
46*7c478bd9Sstevel@tonic-gate 		istat = signal(SIGINT, SIG_IGN);
47*7c478bd9Sstevel@tonic-gate 		qstat = signal(SIGQUIT, SIG_IGN);
48*7c478bd9Sstevel@tonic-gate 		hstat = signal(SIGHUP, SIG_IGN);
49*7c478bd9Sstevel@tonic-gate 		umask(0);
50*7c478bd9Sstevel@tonic-gate 		if ((fd = creat(file, MFMODE)) == -1)
51*7c478bd9Sstevel@tonic-gate 			sav_errno = errno;
52*7c478bd9Sstevel@tonic-gate 		else
53*7c478bd9Sstevel@tonic-gate 			close(fd);
54*7c478bd9Sstevel@tonic-gate 		umask(7);
55*7c478bd9Sstevel@tonic-gate 		(void) signal(SIGINT, istat);
56*7c478bd9Sstevel@tonic-gate 		(void) signal(SIGQUIT, qstat);
57*7c478bd9Sstevel@tonic-gate 		(void) signal(SIGHUP, hstat);
58*7c478bd9Sstevel@tonic-gate 	}
59*7c478bd9Sstevel@tonic-gate }
60*7c478bd9Sstevel@tonic-gate #else
62*7c478bd9Sstevel@tonic-gate #include <sys/stat.h>
63*7c478bd9Sstevel@tonic-gate #include <fcntl.h>
64*7c478bd9Sstevel@tonic-gate #include <stdio.h>
accessmf(path)66*7c478bd9Sstevel@tonic-gate int accessmf(path)
67*7c478bd9Sstevel@tonic-gate char *path;
68*7c478bd9Sstevel@tonic-gate {
70*7c478bd9Sstevel@tonic-gate struct stat fsb,sb;
71*7c478bd9Sstevel@tonic-gate int mbfd;
72*7c478bd9Sstevel@tonic-gate tryagain:
73*7c478bd9Sstevel@tonic-gate 	if (lstat(path, &sb)) {
74*7c478bd9Sstevel@tonic-gate 		/* file/symlink does not exist, so create one */
75*7c478bd9Sstevel@tonic-gate 		mbfd = open(path,
76*7c478bd9Sstevel@tonic-gate 		    O_APPEND|O_CREAT|O_EXCL|O_WRONLY, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP);
77*7c478bd9Sstevel@tonic-gate 		chmod(path, 0660);
78*7c478bd9Sstevel@tonic-gate 		/* if someone create a symlink/file just ahead */
79*7c478bd9Sstevel@tonic-gate 		/* of us, the create will failed with EEXIST   */
80*7c478bd9Sstevel@tonic-gate 		/* This is what we want, because we do not     */
81*7c478bd9Sstevel@tonic-gate 		/* want someone to re-direct our "create"      */
82*7c478bd9Sstevel@tonic-gate 	        /* request to a another location.              */
83*7c478bd9Sstevel@tonic-gate 		if (mbfd == -1) {
84*7c478bd9Sstevel@tonic-gate 			if (errno == EEXIST)
85*7c478bd9Sstevel@tonic-gate 				goto tryagain;
86*7c478bd9Sstevel@tonic-gate 		}
88*7c478bd9Sstevel@tonic-gate 	/* file/symlink  exist, make sure it is not linked */
89*7c478bd9Sstevel@tonic-gate 	} else if (sb.st_nlink != 1 || S_ISLNK(sb.st_mode)) {
90*7c478bd9Sstevel@tonic-gate 		fprintf(stderr,
91*7c478bd9Sstevel@tonic-gate "%s: security violation, '%s' should not be linked to other file\n", program, path);
92*7c478bd9Sstevel@tonic-gate 		sav_errno = errno;
93*7c478bd9Sstevel@tonic-gate 		return -1;
94*7c478bd9Sstevel@tonic-gate 	} else {
95*7c478bd9Sstevel@tonic-gate 		/* if we get here, there is a pre-existing file, */
96*7c478bd9Sstevel@tonic-gate 		/* and it is not a symlink...			 */
97*7c478bd9Sstevel@tonic-gate 		/* open it, and make sure it is the same file    */
98*7c478bd9Sstevel@tonic-gate 		/* we lstat() before...                          */
99*7c478bd9Sstevel@tonic-gate 		/* this is to guard against someone deleting the */
100*7c478bd9Sstevel@tonic-gate 		/* old file and creat a new symlink in its place */
101*7c478bd9Sstevel@tonic-gate 		/* We are not createing a new file here, but we  */
102*7c478bd9Sstevel@tonic-gate 		/* do not want append to the worng file either   */
103*7c478bd9Sstevel@tonic-gate 		mbfd = open(path, O_APPEND|O_WRONLY, 0);
104*7c478bd9Sstevel@tonic-gate 		if (mbfd != -1 &&
105*7c478bd9Sstevel@tonic-gate 		    (fstat(mbfd, &fsb) || fsb.st_nlink != 1 ||
106*7c478bd9Sstevel@tonic-gate 		    S_ISLNK(fsb.st_mode) || sb.st_dev != fsb.st_dev ||
107*7c478bd9Sstevel@tonic-gate 		    sb.st_ino != fsb.st_ino)) {
108*7c478bd9Sstevel@tonic-gate 			/*  file changed after open */
109*7c478bd9Sstevel@tonic-gate 			fprintf(stderr, "%s: security violation, '%s' inode changed after open\n", program, path);
110*7c478bd9Sstevel@tonic-gate 			(void)close(mbfd);
111*7c478bd9Sstevel@tonic-gate 			return -1;
112*7c478bd9Sstevel@tonic-gate 		}
113*7c478bd9Sstevel@tonic-gate 	}
115*7c478bd9Sstevel@tonic-gate 	if (mbfd == -1) {
116*7c478bd9Sstevel@tonic-gate 		sav_errno = errno;
117*7c478bd9Sstevel@tonic-gate 		return -1;
118*7c478bd9Sstevel@tonic-gate 	}
120*7c478bd9Sstevel@tonic-gate 	return mbfd;
121*7c478bd9Sstevel@tonic-gate }
122*7c478bd9Sstevel@tonic-gate #endif