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.
25 /* we are running this code in autoconf test mode to see which type of setuid
27 #if defined(HAVE_UNISTD_H)
32 #include <sys/types.h>
35 #ifdef HAVE_SYS_PRIV_H
42 #define DEBUG(x, y) printf y
43 #define smb_panic(x) exit(1)
47 /* are we running as non-root? This is used by the regresison test code,
48 and potentially also for sites that want non-root smbd */
49 static uid_t initial_uid;
50 static gid_t initial_gid;
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();
59 initial_gid = getegid();
62 /****************************************************************************
63 some code (eg. winbindd) needs to know what uid we started as
64 ****************************************************************************/
65 uid_t sec_initial_uid(void)
70 /****************************************************************************
71 some code (eg. winbindd, profiling shm) needs to know what gid we started as
72 ****************************************************************************/
73 gid_t sec_initial_gid(void)
78 /****************************************************************************
79 are we running in non-root mode?
80 ****************************************************************************/
81 BOOL non_root_mode(void)
83 return (initial_uid != (uid_t)0);
86 /****************************************************************************
87 abort if we haven't set the uid correctly
88 ****************************************************************************/
89 static void assert_uid(uid_t ruid, uid_t euid)
91 if ((euid != (uid_t)-1 && geteuid() != euid) ||
92 (ruid != (uid_t)-1 && getuid() != ruid)) {
93 if (!non_root_mode()) {
94 DEBUG(0,("Failed to set uid privileges to (%d,%d) now set to (%d,%d)\n",
96 (int)getuid(), (int)geteuid()));
97 smb_panic("failed to set uid\n");
103 /****************************************************************************
104 abort if we haven't set the gid correctly
105 ****************************************************************************/
106 static void assert_gid(gid_t rgid, gid_t egid)
108 if ((egid != (gid_t)-1 && getegid() != egid) ||
109 (rgid != (gid_t)-1 && getgid() != rgid)) {
110 if (!non_root_mode()) {
111 DEBUG(0,("Failed to set gid privileges to (%d,%d) now set to (%d,%d) uid=(%d,%d)\n",
112 (int)rgid, (int)egid,
113 (int)getgid(), (int)getegid(),
114 (int)getuid(), (int)geteuid()));
115 smb_panic("failed to set gid\n");
121 /****************************************************************************
122 Gain root privilege before doing something.
123 We want to end up with ruid==euid==0
124 ****************************************************************************/
125 void gain_root_privilege(void)
140 setuidx(ID_EFFECTIVE, 0);
144 /* this is needed on some systems */
151 /****************************************************************************
152 Ensure our real and effective groups are zero.
153 we want to end up with rgid==egid==0
154 ****************************************************************************/
155 void gain_root_group_privilege(void)
170 setgidx(ID_EFFECTIVE, 0);
180 /****************************************************************************
181 Set *only* the effective uid.
182 we want to end up with ruid==0 and euid==uid
183 ****************************************************************************/
184 void set_effective_uid(uid_t uid)
187 setresuid(-1,uid,-1);
199 setuidx(ID_EFFECTIVE, uid);
205 /****************************************************************************
206 Set *only* the effective gid.
207 we want to end up with rgid==0 and egid==gid
208 ****************************************************************************/
209 void set_effective_gid(gid_t gid)
212 setresgid(-1,gid,-1);
224 setgidx(ID_EFFECTIVE, gid);
230 static uid_t saved_euid, saved_ruid;
232 /****************************************************************************
233 save the real and effective uid for later restoration. Used by the quotas
235 ****************************************************************************/
236 void save_re_uid(void)
238 saved_ruid = getuid();
239 saved_euid = geteuid();
243 /****************************************************************************
245 ****************************************************************************/
246 void restore_re_uid(void)
248 set_effective_uid(0);
251 setresuid(saved_ruid, saved_euid, -1);
253 setreuid(saved_ruid, -1);
254 setreuid(-1,saved_euid);
256 setuidx(ID_REAL, saved_ruid);
257 setuidx(ID_EFFECTIVE, saved_euid);
259 set_effective_uid(saved_euid);
260 if (getuid() != saved_ruid)
262 set_effective_uid(saved_euid);
265 assert_uid(saved_ruid, saved_euid);
268 /****************************************************************************
269 set the real AND effective uid to the current effective uid in a way that
270 allows root to be regained.
271 This is only possible on some platforms.
272 ****************************************************************************/
275 uid_t uid = geteuid();
278 setresuid(geteuid(), -1, -1);
297 assert_uid(uid, uid);
302 /****************************************************************************
303 Become the specified uid and gid - permanently !
304 there should be no way back if possible
305 ****************************************************************************/
306 void become_user_permanently(uid_t uid, gid_t gid)
309 * First - gain root privilege. We do this to ensure
310 * we can lose it again.
313 gain_root_privilege();
314 gain_root_group_privilege();
317 setresgid(gid,gid,gid);
319 setresuid(uid,uid,uid);
339 setgidx(ID_REAL, gid);
340 setgidx(ID_EFFECTIVE, gid);
342 setuidx(ID_REAL, uid);
343 setuidx(ID_EFFECTIVE, uid);
347 assert_uid(uid, uid);
348 assert_gid(gid, gid);
353 /****************************************************************************
354 this function just checks that we don't get ENOSYS back
355 ****************************************************************************/
356 static int have_syscall(void)
373 setuidx(ID_EFFECTIVE, -1);
376 if (errno == ENOSYS) return -1;
384 #if (defined(AIX) && defined(USE_SETREUID))
385 /* setreuid is badly broken on AIX 4.1, we avoid it completely */
386 fprintf(stderr,"avoiding possibly broken setreuid\n");
390 /* if not running as root then at least check to see if we get ENOSYS - this
391 handles Linux 2.0.x with glibc 2.1 */
392 fprintf(stderr,"not running as root: checking for ENOSYS\n");
393 exit(have_syscall());
396 gain_root_privilege();
397 gain_root_group_privilege();
398 set_effective_gid(1);
399 set_effective_uid(1);
402 gain_root_privilege();
403 gain_root_group_privilege();
404 become_user_permanently(1, 1);
407 fprintf(stderr,"uid not set permanently\n");
417 /****************************************************************************
418 Check if we are setuid root. Used in libsmb and smbpasswd parinoia checks.
419 ****************************************************************************/
420 BOOL is_setuid_root(void)
422 return (geteuid() == (uid_t)0) && (getuid() != (uid_t)0);