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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #pragma ident "%Z%%M% %I% %E% SMI"
28
29 #include <sys/types.h>
30 #include <unistd.h>
31 #include <dlfcn.h>
32 #include "k5-int.h"
33
34 #define KRB5_UID "app_krb5_user_uid"
35
36 /*
37 * mech_krb5 makes various calls to getuid(). When employed by gssd(1M) and
38 * ktkt_warnd(1M), app_krb5_user_uid() is used to select a given user's
39 * credential cache, rather than the id of the process.
40 */
41 uid_t
krb5_getuid()42 krb5_getuid()
43 {
44 static uid_t (*gptr)() = NULL;
45 void *handle;
46
47 if (gptr == NULL) {
48 /*
49 * Specifically look for app_krb5_user_uid() in the application,
50 * and don't fall into an exhaustive search through all of the
51 * process dependencies. This interface is suplied from
52 * gssd(1M) and ktkt_warnd(1M).
53 */
54 if (((handle = dlopen(0, (RTLD_LAZY | RTLD_FIRST))) == NULL) ||
55 ((gptr = (uid_t (*)())dlsym(handle, KRB5_UID)) == NULL)) {
56 /*
57 * Fall back to the default getuid(), which is probably
58 * libc.
59 */
60 gptr = &getuid;
61 }
62 }
63
64 /*
65 * Return the appropriate uid. Note, if a default getuid() couldn't
66 * be found, the getuid assignment would have failed to relocate, and
67 * hence this module would fail to load.
68 */
69 return ((*gptr)());
70 }
71