2 Unix SMB/Netbios implementation.
4 Copyright (C) Jeremy Allison 1998.
5 rewritten for version 2.0.6 by Tridge
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 extern int DEBUGLEVEL;
26 /* we are running this code in autoconf test mode to see which type of setuid
28 #if defined(HAVE_UNISTD_H)
33 #include <sys/types.h>
36 #ifdef HAVE_SYS_PRIV_H
43 #define DEBUG(x, y) printf y
44 #define smb_panic(x) exit(1)
47 /****************************************************************************
48 abort if we haven't set the uid correctly
49 ****************************************************************************/
50 static void assert_uid(uid_t ruid, uid_t euid)
52 if ((euid != (uid_t)-1 && geteuid() != euid) ||
53 (ruid != (uid_t)-1 && getuid() != ruid)) {
54 DEBUG(0,("Failed to set uid privileges to (%d,%d) now set to (%d,%d)\n",
56 (int)getuid(), (int)geteuid()));
57 smb_panic("failed to set uid\n");
62 /****************************************************************************
63 abort if we haven't set the gid correctly
64 ****************************************************************************/
65 static void assert_gid(gid_t rgid, gid_t egid)
67 if ((egid != (gid_t)-1 && getegid() != egid) ||
68 (rgid != (gid_t)-1 && getgid() != rgid)) {
69 DEBUG(0,("Failed to set gid privileges to (%d,%d) now set to (%d,%d) uid=(%d,%d)\n",
71 (int)getgid(), (int)getegid(),
72 (int)getuid(), (int)geteuid()));
73 smb_panic("failed to set gid\n");
78 /****************************************************************************
79 Gain root privilege before doing something.
80 We want to end up with ruid==euid==0
81 ****************************************************************************/
82 void gain_root_privilege(void)
97 setuidx(ID_EFFECTIVE, 0);
101 /* this is needed on some systems */
108 /****************************************************************************
109 Ensure our real and effective groups are zero.
110 we want to end up with rgid==egid==0
111 ****************************************************************************/
112 void gain_root_group_privilege(void)
127 setgidx(ID_EFFECTIVE, 0);
137 /****************************************************************************
138 Set *only* the effective uid.
139 we want to end up with ruid==0 and euid==uid
140 ****************************************************************************/
141 void set_effective_uid(uid_t uid)
144 setresuid(-1,uid,-1);
156 setuidx(ID_EFFECTIVE, uid);
162 /****************************************************************************
163 Set *only* the effective gid.
164 we want to end up with rgid==0 and egid==gid
165 ****************************************************************************/
166 void set_effective_gid(gid_t gid)
169 setresgid(-1,gid,-1);
181 setgidx(ID_EFFECTIVE, gid);
187 static uid_t saved_euid, saved_ruid;
189 /****************************************************************************
190 save the real and effective uid for later restoration. Used by the quotas
192 ****************************************************************************/
193 void save_re_uid(void)
195 saved_ruid = getuid();
196 saved_euid = geteuid();
200 /****************************************************************************
202 ****************************************************************************/
203 void restore_re_uid(void)
205 set_effective_uid(0);
208 setresuid(saved_ruid, saved_euid, -1);
210 setreuid(saved_ruid, -1);
211 setreuid(-1,saved_euid);
213 setuidx(ID_REAL, saved_ruid);
214 setuidx(ID_EFFECTIVE, saved_euid);
216 set_effective_uid(saved_euid);
217 if (getuid() != saved_ruid)
219 set_effective_uid(saved_euid);
222 assert_uid(saved_ruid, saved_euid);
225 /****************************************************************************
226 set the real AND effective uid to the current effective uid in a way that
227 allows root to be regained.
228 This is only possible on some platforms.
229 ****************************************************************************/
232 uid_t uid = geteuid();
235 setresuid(geteuid(), -1, -1);
254 assert_uid(uid, uid);
259 /****************************************************************************
260 Become the specified uid and gid - permanently !
261 there should be no way back if possible
262 ****************************************************************************/
263 void become_user_permanently(uid_t uid, gid_t gid)
266 * First - gain root privilege. We do this to ensure
267 * we can lose it again.
270 gain_root_privilege();
271 gain_root_group_privilege();
274 setresgid(gid,gid,gid);
276 setresuid(uid,uid,uid);
296 setgidx(ID_REAL, gid);
297 setgidx(ID_EFFECTIVE, gid);
299 setuidx(ID_REAL, uid);
300 setuidx(ID_EFFECTIVE, uid);
304 assert_uid(uid, uid);
305 assert_gid(gid, gid);
309 /****************************************************************************
310 this function just checks that we don't get ENOSYS back
311 ****************************************************************************/
312 static int have_syscall(void)
329 setuidx(ID_EFFECTIVE, -1);
332 if (errno == ENOSYS) return -1;
341 #if (defined(AIX) && defined(USE_SETREUID))
342 /* setreuid is badly broken on AIX 4.1, we avoid it completely */
343 fprintf(stderr,"avoiding possibly broken setreuid\n");
347 /* if not running as root then at least check to see if we get ENOSYS - this
348 handles Linux 2.0.x with glibc 2.1 */
349 fprintf(stderr,"not running as root: checking for ENOSYS\n");
350 exit(have_syscall());
353 gain_root_privilege();
354 gain_root_group_privilege();
355 set_effective_gid(1);
356 set_effective_uid(1);
359 gain_root_privilege();
360 gain_root_group_privilege();
361 become_user_permanently(1, 1);
364 fprintf(stderr,"uid not set permanently\n");