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)
48 /* are we running as non-root? This is used by the regresison test code,
49 and potentially also for sites that want non-root smbd */
50 static uid_t initial_uid;
52 /****************************************************************************
53 remember what uid we got started as - this allows us to run correctly
54 as non-root while catching trapdoor systems
55 ****************************************************************************/
58 initial_uid = geteuid();
61 /****************************************************************************
62 some code (eg. winbindd) needs to know what uid we started as
63 ****************************************************************************/
64 uid_t sec_initial_uid(void)
69 /****************************************************************************
70 are we running in non-root mode?
71 ****************************************************************************/
72 BOOL non_root_mode(void)
74 return (initial_uid != (uid_t)0);
77 /****************************************************************************
78 abort if we haven't set the uid correctly
79 ****************************************************************************/
80 static void assert_uid(uid_t ruid, uid_t euid)
82 if ((euid != (uid_t)-1 && geteuid() != euid) ||
83 (ruid != (uid_t)-1 && getuid() != ruid)) {
84 if (!non_root_mode()) {
85 DEBUG(0,("Failed to set uid privileges to (%d,%d) now set to (%d,%d)\n",
87 (int)getuid(), (int)geteuid()));
88 smb_panic("failed to set uid\n");
94 /****************************************************************************
95 abort if we haven't set the gid correctly
96 ****************************************************************************/
97 static void assert_gid(gid_t rgid, gid_t egid)
99 if ((egid != (gid_t)-1 && getegid() != egid) ||
100 (rgid != (gid_t)-1 && getgid() != rgid)) {
101 if (!non_root_mode()) {
102 DEBUG(0,("Failed to set gid privileges to (%d,%d) now set to (%d,%d) uid=(%d,%d)\n",
103 (int)rgid, (int)egid,
104 (int)getgid(), (int)getegid(),
105 (int)getuid(), (int)geteuid()));
106 smb_panic("failed to set gid\n");
112 /****************************************************************************
113 Gain root privilege before doing something.
114 We want to end up with ruid==euid==0
115 ****************************************************************************/
116 void gain_root_privilege(void)
131 setuidx(ID_EFFECTIVE, 0);
135 /* this is needed on some systems */
142 /****************************************************************************
143 Ensure our real and effective groups are zero.
144 we want to end up with rgid==egid==0
145 ****************************************************************************/
146 void gain_root_group_privilege(void)
161 setgidx(ID_EFFECTIVE, 0);
171 /****************************************************************************
172 Set *only* the effective uid.
173 we want to end up with ruid==0 and euid==uid
174 ****************************************************************************/
175 void set_effective_uid(uid_t uid)
178 setresuid(-1,uid,-1);
190 setuidx(ID_EFFECTIVE, uid);
196 /****************************************************************************
197 Set *only* the effective gid.
198 we want to end up with rgid==0 and egid==gid
199 ****************************************************************************/
200 void set_effective_gid(gid_t gid)
203 setresgid(-1,gid,-1);
215 setgidx(ID_EFFECTIVE, gid);
221 static uid_t saved_euid, saved_ruid;
223 /****************************************************************************
224 save the real and effective uid for later restoration. Used by the quotas
226 ****************************************************************************/
227 void save_re_uid(void)
229 saved_ruid = getuid();
230 saved_euid = geteuid();
234 /****************************************************************************
236 ****************************************************************************/
237 void restore_re_uid(void)
239 set_effective_uid(0);
242 setresuid(saved_ruid, saved_euid, -1);
244 setreuid(saved_ruid, -1);
245 setreuid(-1,saved_euid);
247 setuidx(ID_REAL, saved_ruid);
248 setuidx(ID_EFFECTIVE, saved_euid);
250 set_effective_uid(saved_euid);
251 if (getuid() != saved_ruid)
253 set_effective_uid(saved_euid);
256 assert_uid(saved_ruid, saved_euid);
259 /****************************************************************************
260 set the real AND effective uid to the current effective uid in a way that
261 allows root to be regained.
262 This is only possible on some platforms.
263 ****************************************************************************/
266 uid_t uid = geteuid();
269 setresuid(geteuid(), -1, -1);
288 assert_uid(uid, uid);
293 /****************************************************************************
294 Become the specified uid and gid - permanently !
295 there should be no way back if possible
296 ****************************************************************************/
297 void become_user_permanently(uid_t uid, gid_t gid)
300 * First - gain root privilege. We do this to ensure
301 * we can lose it again.
304 gain_root_privilege();
305 gain_root_group_privilege();
308 setresgid(gid,gid,gid);
310 setresuid(uid,uid,uid);
330 setgidx(ID_REAL, gid);
331 setgidx(ID_EFFECTIVE, gid);
333 setuidx(ID_REAL, uid);
334 setuidx(ID_EFFECTIVE, uid);
338 assert_uid(uid, uid);
339 assert_gid(gid, gid);
344 /****************************************************************************
345 this function just checks that we don't get ENOSYS back
346 ****************************************************************************/
347 static int have_syscall(void)
364 setuidx(ID_EFFECTIVE, -1);
367 if (errno == ENOSYS) return -1;
375 #if (defined(AIX) && defined(USE_SETREUID))
376 /* setreuid is badly broken on AIX 4.1, we avoid it completely */
377 fprintf(stderr,"avoiding possibly broken setreuid\n");
381 /* if not running as root then at least check to see if we get ENOSYS - this
382 handles Linux 2.0.x with glibc 2.1 */
383 fprintf(stderr,"not running as root: checking for ENOSYS\n");
384 exit(have_syscall());
387 gain_root_privilege();
388 gain_root_group_privilege();
389 set_effective_gid(1);
390 set_effective_uid(1);
393 gain_root_privilege();
394 gain_root_group_privilege();
395 become_user_permanently(1, 1);
398 fprintf(stderr,"uid not set permanently\n");