xref: /onnv-gate/usr/src/lib/gss_mechs/mech_krb5/krb5/krb/getuid.c (revision 4271:dda1ded496b7)
1*4271Srie /*
2*4271Srie  * CDDL HEADER START
3*4271Srie  *
4*4271Srie  * The contents of this file are subject to the terms of the
5*4271Srie  * Common Development and Distribution License (the "License").
6*4271Srie  * You may not use this file except in compliance with the License.
7*4271Srie  *
8*4271Srie  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*4271Srie  * or http://www.opensolaris.org/os/licensing.
10*4271Srie  * See the License for the specific language governing permissions
11*4271Srie  * and limitations under the License.
12*4271Srie  *
13*4271Srie  * When distributing Covered Code, include this CDDL HEADER in each
14*4271Srie  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*4271Srie  * If applicable, add the following below this CDDL HEADER, with the
16*4271Srie  * fields enclosed by brackets "[]" replaced with your own identifying
17*4271Srie  * information: Portions Copyright [yyyy] [name of copyright owner]
18*4271Srie  *
19*4271Srie  * CDDL HEADER END
20*4271Srie  */
21*4271Srie 
22*4271Srie /*
23*4271Srie  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
24*4271Srie  * Use is subject to license terms.
25*4271Srie  */
26*4271Srie 
27*4271Srie #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*4271Srie 
29*4271Srie #include	<sys/types.h>
30*4271Srie #include	<unistd.h>
31*4271Srie #include	<dlfcn.h>
32*4271Srie #include	"k5-int.h"
33*4271Srie 
34*4271Srie #define		KRB5_UID	"app_krb5_user_uid"
35*4271Srie 
36*4271Srie /*
37*4271Srie  * mech_krb5 makes various calls to getuid().  When employed by gssd(1M) and
38*4271Srie  * ktkt_warnd(1M), app_krb5_user_uid() is used to select a given user's
39*4271Srie  * credential cache, rather than the id of the process.
40*4271Srie  */
41*4271Srie uid_t
krb5_getuid()42*4271Srie krb5_getuid()
43*4271Srie {
44*4271Srie 	static uid_t	(*gptr)() = NULL;
45*4271Srie 	void		*handle;
46*4271Srie 
47*4271Srie 	if (gptr == NULL) {
48*4271Srie 		/*
49*4271Srie 		 * Specifically look for app_krb5_user_uid() in the application,
50*4271Srie 		 * and don't fall into an exhaustive search through all of the
51*4271Srie 		 * process dependencies.  This interface is suplied from
52*4271Srie 		 * gssd(1M) and ktkt_warnd(1M).
53*4271Srie 		 */
54*4271Srie 		if (((handle = dlopen(0, (RTLD_LAZY | RTLD_FIRST))) == NULL) ||
55*4271Srie 		    ((gptr = (uid_t (*)())dlsym(handle, KRB5_UID)) == NULL)) {
56*4271Srie 			/*
57*4271Srie 			 * Fall back to the default getuid(), which is probably
58*4271Srie 			 * libc.
59*4271Srie 			 */
60*4271Srie 			gptr = &getuid;
61*4271Srie 		}
62*4271Srie 	}
63*4271Srie 
64*4271Srie 	/*
65*4271Srie 	 * Return the appropriate uid.  Note, if a default getuid() couldn't
66*4271Srie 	 * be found, the getuid assignment would have failed to relocate, and
67*4271Srie 	 * hence this module would fail to load.
68*4271Srie 	 */
69*4271Srie 	return ((*gptr)());
70*4271Srie }
71