1 /*	$OpenBSD: pt_file.c,v 1.9 2003/06/11 06:22:14 deraadt Exp $	*/
2 /*	$NetBSD: pt_file.c,v 1.7 1995/06/06 19:54:30 mycroft Exp $	*/
3 
4 /*
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  * All rights reserved.
8  *
9  * This code is derived from software donated to Berkeley by
10  * Jan-Simon Pendry.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: Id: pt_file.c,v 1.1 1992/05/25 21:43:09 jsp Exp
37  *	@(#)pt_file.c	8.3 (Berkeley) 7/3/94
38  */
39 
40 #include <stdio.h>
41 #include <unistd.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <errno.h>
45 #include <fcntl.h>
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/syslog.h>
49 
50 #include "portald.h"
51 
52 int
portal_file(struct portal_cred * pcr,char * key,char ** v,int so,int * fdp)53 portal_file(struct portal_cred *pcr, char *key, char **v, int so, int *fdp)
54 {
55 	int fd;
56 	char pbuf[MAXPATHLEN];
57 	int error;
58 
59 	pbuf[0] = '/';
60 	(void)strncpy(pbuf+1, key + (v[1] ? strlen(v[1]) : 0), sizeof pbuf-2);
61 	pbuf[sizeof pbuf-1] = '\0';
62 
63 #ifdef DEBUG
64 	(void)printf("path = %s, uid = %u, gid = %u\n", pbuf, pcr->pcr_uid,
65 	    pcr->pcr_gid);
66 #endif
67 
68 	if (setegid(pcr->pcr_gid) < 0 ||
69 	    setgroups(pcr->pcr_ngroups, pcr->pcr_groups) < 0)
70 		return (errno);
71 
72 	if (seteuid(pcr->pcr_uid) < 0)
73 		return (errno);
74 
75 
76 	error = 0;
77 
78 	fd = open(pbuf, O_RDWR|O_CREAT, 0666);
79 	if (fd < 0) {
80 	        if (errno == EISDIR) {
81 			errno = 0;
82 			fd = open(pbuf, O_RDONLY);
83 		}
84 		if (fd < 0)
85 			error = errno;
86 	}
87 
88 	if (seteuid((uid_t) 0) < 0) {	/* XXX - should reset gidset too */
89 		error = errno;
90 		syslog(LOG_ERR, "setcred: %m");
91 		if (fd >= 0) {
92 			(void)close(fd);
93 			fd = -1;
94 		}
95 	}
96 
97 	if (error == 0)
98 		*fdp = fd;
99 
100 #ifdef DEBUG
101 	(void)fprintf(stderr, "pt_file returns *fdp = %d, error = %d\n",
102 	    *fdp, error);
103 #endif
104 
105 	return (error);
106 }
107