2 Unix SMB/CIFS implementation.
3 Copyright (C) Jeremy Allison 1998.
4 rewritten for version 2.0.6 by Tridge
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 /* we are running this code in autoconf test mode to see which type of setuid
26 #if defined(HAVE_UNISTD_H)
31 #include <sys/types.h>
34 #ifdef HAVE_SYS_PRIV_H
41 #define DEBUG(x, y) printf y
42 #define smb_panic(x) exit(1)
46 /* are we running as non-root? This is used by the regresison test code,
47 and potentially also for sites that want non-root smbd */
48 static uid_t initial_uid;
49 static gid_t initial_gid;
51 /****************************************************************************
52 remember what uid we got started as - this allows us to run correctly
53 as non-root while catching trapdoor systems
54 ****************************************************************************/
57 initial_uid = geteuid();
58 initial_gid = getegid();
61 /****************************************************************************
62 some code (eg. winbindd) needs to know what uid we started as
63 ****************************************************************************/
64 uid_t sec_initial_uid(void)
69 /****************************************************************************
70 some code (eg. winbindd, profiling shm) needs to know what gid we started as
71 ****************************************************************************/
72 gid_t sec_initial_gid(void)
77 /****************************************************************************
78 are we running in non-root mode?
79 ****************************************************************************/
80 BOOL non_root_mode(void)
82 return (initial_uid != (uid_t)0);
85 /****************************************************************************
86 abort if we haven't set the uid correctly
87 ****************************************************************************/
88 static void assert_uid(uid_t ruid, uid_t euid)
90 if ((euid != (uid_t)-1 && geteuid() != euid) ||
91 (ruid != (uid_t)-1 && getuid() != ruid)) {
92 if (!non_root_mode()) {
93 DEBUG(0,("Failed to set uid privileges to (%d,%d) now set to (%d,%d)\n",
95 (int)getuid(), (int)geteuid()));
96 smb_panic("failed to set uid\n");
102 /****************************************************************************
103 abort if we haven't set the gid correctly
104 ****************************************************************************/
105 static void assert_gid(gid_t rgid, gid_t egid)
107 if ((egid != (gid_t)-1 && getegid() != egid) ||
108 (rgid != (gid_t)-1 && getgid() != rgid)) {
109 if (!non_root_mode()) {
110 DEBUG(0,("Failed to set gid privileges to (%d,%d) now set to (%d,%d) uid=(%d,%d)\n",
111 (int)rgid, (int)egid,
112 (int)getgid(), (int)getegid(),
113 (int)getuid(), (int)geteuid()));
114 smb_panic("failed to set gid\n");
120 /****************************************************************************
121 Gain root privilege before doing something.
122 We want to end up with ruid==euid==0
123 ****************************************************************************/
124 void gain_root_privilege(void)
139 setuidx(ID_EFFECTIVE, 0);
143 /* this is needed on some systems */
150 /****************************************************************************
151 Ensure our real and effective groups are zero.
152 we want to end up with rgid==egid==0
153 ****************************************************************************/
154 void gain_root_group_privilege(void)
169 setgidx(ID_EFFECTIVE, 0);
179 /****************************************************************************
180 Set effective uid, and possibly the real uid too.
181 We want to end up with either:
183 ruid==uid and euid==uid
187 ruid==0 and euid==uid
189 depending on what the local OS will allow us to regain root from.
190 ****************************************************************************/
191 void set_effective_uid(uid_t uid)
194 /* Set the effective as well as the real uid. */
195 setresuid(uid,uid,-1);
207 setuidx(ID_EFFECTIVE, uid);
213 /****************************************************************************
214 Set *only* the effective gid.
215 we want to end up with rgid==0 and egid==gid
216 ****************************************************************************/
217 void set_effective_gid(gid_t gid)
220 setresgid(-1,gid,-1);
232 setgidx(ID_EFFECTIVE, gid);
238 static uid_t saved_euid, saved_ruid;
239 static gid_t saved_egid, saved_rgid;
241 /****************************************************************************
242 save the real and effective uid for later restoration. Used by the quotas
244 ****************************************************************************/
245 void save_re_uid(void)
247 saved_ruid = getuid();
248 saved_euid = geteuid();
252 /****************************************************************************
254 ****************************************************************************/
255 void restore_re_uid(void)
257 set_effective_uid(0);
260 setresuid(saved_ruid, saved_euid, -1);
262 setreuid(saved_ruid, -1);
263 setreuid(-1,saved_euid);
265 setuidx(ID_REAL, saved_ruid);
266 setuidx(ID_EFFECTIVE, saved_euid);
268 set_effective_uid(saved_euid);
269 if (getuid() != saved_ruid)
271 set_effective_uid(saved_euid);
274 assert_uid(saved_ruid, saved_euid);
278 /****************************************************************************
279 save the real and effective gid for later restoration. Used by the
281 ****************************************************************************/
282 void save_re_gid(void)
284 saved_rgid = getgid();
285 saved_egid = getegid();
288 /****************************************************************************
290 ****************************************************************************/
291 void restore_re_gid(void)
294 setresgid(saved_rgid, saved_egid, -1);
296 setregid(saved_rgid, -1);
297 setregid(-1,saved_egid);
299 setgidx(ID_REAL, saved_rgid);
300 setgidx(ID_EFFECTIVE, saved_egid);
302 set_effective_gid(saved_egid);
303 if (getgid() != saved_rgid)
305 set_effective_gid(saved_egid);
308 assert_gid(saved_rgid, saved_egid);
312 /****************************************************************************
313 set the real AND effective uid to the current effective uid in a way that
314 allows root to be regained.
315 This is only possible on some platforms.
316 ****************************************************************************/
319 uid_t uid = geteuid();
322 setresuid(geteuid(), -1, -1);
341 assert_uid(uid, uid);
346 /****************************************************************************
347 Become the specified uid and gid - permanently !
348 there should be no way back if possible
349 ****************************************************************************/
350 void become_user_permanently(uid_t uid, gid_t gid)
353 * First - gain root privilege. We do this to ensure
354 * we can lose it again.
357 gain_root_privilege();
358 gain_root_group_privilege();
361 setresgid(gid,gid,gid);
363 setresuid(uid,uid,uid);
383 setgidx(ID_REAL, gid);
384 setgidx(ID_EFFECTIVE, gid);
386 setuidx(ID_REAL, uid);
387 setuidx(ID_EFFECTIVE, uid);
391 assert_uid(uid, uid);
392 assert_gid(gid, gid);
397 /****************************************************************************
398 this function just checks that we don't get ENOSYS back
399 ****************************************************************************/
400 static int have_syscall(void)
417 setuidx(ID_EFFECTIVE, -1);
420 if (errno == ENOSYS) return -1;
428 #if (defined(AIX) && defined(USE_SETREUID))
429 /* setreuid is badly broken on AIX 4.1, we avoid it completely */
430 fprintf(stderr,"avoiding possibly broken setreuid\n");
434 /* if not running as root then at least check to see if we get ENOSYS - this
435 handles Linux 2.0.x with glibc 2.1 */
436 fprintf(stderr,"not running as root: checking for ENOSYS\n");
437 exit(have_syscall());
440 gain_root_privilege();
441 gain_root_group_privilege();
442 set_effective_gid(1);
443 set_effective_uid(1);
446 gain_root_privilege();
447 gain_root_group_privilege();
448 become_user_permanently(1, 1);
451 fprintf(stderr,"uid not set permanently\n");
461 /****************************************************************************
462 Check if we are setuid root. Used in libsmb and smbpasswd paranoia checks.
463 ****************************************************************************/
464 BOOL is_setuid_root(void)
466 return (geteuid() == (uid_t)0) && (getuid() != (uid_t)0);