clean up lib64 linking paths the same way as lib
[Samba/gebeck_regimport.git] / source3 / smbd / sec_ctx.c
blob4b9e5d47276ca36ea27e286fe0d3a8d0441e0a3f
1 /*
2 Unix SMB/CIFS implementation.
3 uid/user handling
4 Copyright (C) Tim Potter 2000
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 3 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, see <http://www.gnu.org/licenses/>.
20 #include "includes.h"
21 #include "smbd/globals.h"
23 extern struct current_user current_user;
25 /****************************************************************************
26 Are two UNIX tokens equal ?
27 ****************************************************************************/
29 bool unix_token_equal(const UNIX_USER_TOKEN *t1, const UNIX_USER_TOKEN *t2)
31 if (t1->uid != t2->uid || t1->gid != t2->gid ||
32 t1->ngroups != t2->ngroups) {
33 return false;
35 if (memcmp(t1->groups, t2->groups,
36 t1->ngroups*sizeof(gid_t)) != 0) {
37 return false;
39 return true;
42 /****************************************************************************
43 Become the specified uid.
44 ****************************************************************************/
46 static bool become_uid(uid_t uid)
48 /* Check for dodgy uid values */
50 if (uid == (uid_t)-1 ||
51 ((sizeof(uid_t) == 2) && (uid == (uid_t)65535))) {
52 if (!become_uid_done) {
53 DEBUG(1,("WARNING: using uid %d is a security risk\n",
54 (int)uid));
55 become_uid_done = true;
59 /* Set effective user id */
61 set_effective_uid(uid);
63 DO_PROFILE_INC(uid_changes);
64 return True;
67 /****************************************************************************
68 Become the specified gid.
69 ****************************************************************************/
71 static bool become_gid(gid_t gid)
73 /* Check for dodgy gid values */
75 if (gid == (gid_t)-1 || ((sizeof(gid_t) == 2) &&
76 (gid == (gid_t)65535))) {
77 if (!become_gid_done) {
78 DEBUG(1,("WARNING: using gid %d is a security risk\n",
79 (int)gid));
80 become_gid_done = true;
84 /* Set effective group id */
86 set_effective_gid(gid);
87 return True;
90 /****************************************************************************
91 Become the specified uid and gid.
92 ****************************************************************************/
94 static bool become_id(uid_t uid, gid_t gid)
96 return become_gid(gid) && become_uid(uid);
99 /****************************************************************************
100 Drop back to root privileges in order to change to another user.
101 ****************************************************************************/
103 static void gain_root(void)
105 if (non_root_mode()) {
106 return;
109 if (geteuid() != 0) {
110 set_effective_uid(0);
112 if (geteuid() != 0) {
113 DEBUG(0,
114 ("Warning: You appear to have a trapdoor "
115 "uid system\n"));
119 if (getegid() != 0) {
120 set_effective_gid(0);
122 if (getegid() != 0) {
123 DEBUG(0,
124 ("Warning: You appear to have a trapdoor "
125 "gid system\n"));
130 /****************************************************************************
131 Get the list of current groups.
132 ****************************************************************************/
134 static int get_current_groups(gid_t gid, size_t *p_ngroups, gid_t **p_groups)
136 int i;
137 gid_t grp;
138 int ngroups;
139 gid_t *groups = NULL;
141 (*p_ngroups) = 0;
142 (*p_groups) = NULL;
144 /* this looks a little strange, but is needed to cope with
145 systems that put the current egid in the group list
146 returned from getgroups() (tridge) */
147 save_re_gid();
148 set_effective_gid(gid);
149 setgid(gid);
151 ngroups = sys_getgroups(0,&grp);
152 if (ngroups <= 0) {
153 goto fail;
156 if((groups = SMB_MALLOC_ARRAY(gid_t, ngroups+1)) == NULL) {
157 DEBUG(0,("setup_groups malloc fail !\n"));
158 goto fail;
161 if ((ngroups = sys_getgroups(ngroups,groups)) == -1) {
162 goto fail;
165 restore_re_gid();
167 (*p_ngroups) = ngroups;
168 (*p_groups) = groups;
170 DEBUG( 3, ( "get_current_groups: user is in %u groups: ", ngroups));
171 for (i = 0; i < ngroups; i++ ) {
172 DEBUG( 3, ( "%s%d", (i ? ", " : ""), (int)groups[i] ) );
174 DEBUG( 3, ( "\n" ) );
176 return ngroups;
178 fail:
179 SAFE_FREE(groups);
180 restore_re_gid();
181 return -1;
184 /****************************************************************************
185 Create a new security context on the stack. It is the same as the old
186 one. User changes are done using the set_sec_ctx() function.
187 ****************************************************************************/
189 bool push_sec_ctx(void)
191 struct sec_ctx *ctx_p;
193 /* Check we don't overflow our stack */
195 if (sec_ctx_stack_ndx == MAX_SEC_CTX_DEPTH) {
196 DEBUG(0, ("Security context stack overflow!\n"));
197 smb_panic("Security context stack overflow!");
200 /* Store previous user context */
202 sec_ctx_stack_ndx++;
204 ctx_p = &sec_ctx_stack[sec_ctx_stack_ndx];
206 ctx_p->ut.uid = geteuid();
207 ctx_p->ut.gid = getegid();
209 DEBUG(3, ("push_sec_ctx(%u, %u) : sec_ctx_stack_ndx = %d\n",
210 (unsigned int)ctx_p->ut.uid, (unsigned int)ctx_p->ut.gid, sec_ctx_stack_ndx ));
212 ctx_p->token = dup_nt_token(NULL,
213 sec_ctx_stack[sec_ctx_stack_ndx-1].token);
215 ctx_p->ut.ngroups = sys_getgroups(0, NULL);
217 if (ctx_p->ut.ngroups != 0) {
218 if (!(ctx_p->ut.groups = SMB_MALLOC_ARRAY(gid_t, ctx_p->ut.ngroups))) {
219 DEBUG(0, ("Out of memory in push_sec_ctx()\n"));
220 TALLOC_FREE(ctx_p->token);
221 return False;
224 sys_getgroups(ctx_p->ut.ngroups, ctx_p->ut.groups);
225 } else {
226 ctx_p->ut.groups = NULL;
229 return True;
232 /****************************************************************************
233 Change UNIX security context. Calls panic if not successful so no return value.
234 ****************************************************************************/
236 #ifndef HAVE_DARWIN_INITGROUPS
238 /* Normal credential switch path. */
240 static void set_unix_security_ctx(uid_t uid, gid_t gid, int ngroups, gid_t *groups)
242 /* Start context switch */
243 gain_root();
244 #ifdef HAVE_SETGROUPS
245 if (sys_setgroups(gid, ngroups, groups) != 0 && !non_root_mode()) {
246 smb_panic("sys_setgroups failed");
248 #endif
249 become_id(uid, gid);
250 /* end context switch */
253 #else /* HAVE_DARWIN_INITGROUPS */
255 /* The Darwin groups implementation is a little unusual. The list of
256 * groups in the kernel credential is not exhaustive, but more like
257 * a cache. The full group list is held in userspace and checked
258 * dynamically.
260 * This is an optional mechanism, and setgroups(2) opts out
261 * of it. That is, if you call setgroups, then the list of groups you
262 * set are the only groups that are ever checked. This is not what we
263 * want. We want to opt in to the dynamic resolution mechanism, so we
264 * need to specify the uid of the user whose group list (cache) we are
265 * setting.
267 * The Darwin rules are:
268 * 1. Thou shalt setegid, initgroups and seteuid IN THAT ORDER
269 * 2. Thou shalt not pass more that NGROUPS_MAX to initgroups
270 * 3. Thou shalt leave the first entry in the groups list well alone
273 #include <sys/syscall.h>
275 static void set_unix_security_ctx(uid_t uid, gid_t gid, int ngroups, gid_t *groups)
277 int max = groups_max();
279 /* Start context switch */
280 gain_root();
282 become_gid(gid);
285 if (syscall(SYS_initgroups, (ngroups > max) ? max : ngroups,
286 groups, uid) == -1 && !non_root_mode()) {
287 DEBUG(0, ("WARNING: failed to set group list "
288 "(%d groups) for UID %ld: %s\n",
289 ngroups, uid, strerror(errno)));
290 smb_panic("sys_setgroups failed");
293 become_uid(uid);
294 /* end context switch */
297 #endif /* HAVE_DARWIN_INITGROUPS */
299 /****************************************************************************
300 Set the current security context to a given user.
301 ****************************************************************************/
303 void set_sec_ctx(uid_t uid, gid_t gid, int ngroups, gid_t *groups, NT_USER_TOKEN *token)
305 struct sec_ctx *ctx_p = &sec_ctx_stack[sec_ctx_stack_ndx];
307 /* Set the security context */
309 DEBUG(3, ("setting sec ctx (%u, %u) - sec_ctx_stack_ndx = %d\n",
310 (unsigned int)uid, (unsigned int)gid, sec_ctx_stack_ndx));
312 debug_nt_user_token(DBGC_CLASS, 5, token);
313 debug_unix_user_token(DBGC_CLASS, 5, uid, gid, ngroups, groups);
315 /* Change uid, gid and supplementary group list. */
316 set_unix_security_ctx(uid, gid, ngroups, groups);
318 ctx_p->ut.ngroups = ngroups;
320 SAFE_FREE(ctx_p->ut.groups);
321 if (token && (token == ctx_p->token)) {
322 smb_panic("DUPLICATE_TOKEN");
325 TALLOC_FREE(ctx_p->token);
327 if (ngroups) {
328 ctx_p->ut.groups = (gid_t *)memdup(groups,
329 sizeof(gid_t) * ngroups);
330 if (!ctx_p->ut.groups) {
331 smb_panic("memdup failed");
333 } else {
334 ctx_p->ut.groups = NULL;
337 if (token) {
338 ctx_p->token = dup_nt_token(NULL, token);
339 if (!ctx_p->token) {
340 smb_panic("dup_nt_token failed");
342 } else {
343 ctx_p->token = NULL;
346 ctx_p->ut.uid = uid;
347 ctx_p->ut.gid = gid;
349 /* Update current_user stuff */
351 current_user.ut.uid = uid;
352 current_user.ut.gid = gid;
353 current_user.ut.ngroups = ngroups;
354 current_user.ut.groups = groups;
355 current_user.nt_user_token = ctx_p->token;
358 /****************************************************************************
359 Become root context.
360 ****************************************************************************/
362 void set_root_sec_ctx(void)
364 /* May need to worry about supplementary groups at some stage */
366 set_sec_ctx(0, 0, 0, NULL, NULL);
369 /****************************************************************************
370 Pop a security context from the stack.
371 ****************************************************************************/
373 bool pop_sec_ctx(void)
375 struct sec_ctx *ctx_p;
376 struct sec_ctx *prev_ctx_p;
378 /* Check for stack underflow */
380 if (sec_ctx_stack_ndx == 0) {
381 DEBUG(0, ("Security context stack underflow!\n"));
382 smb_panic("Security context stack underflow!");
385 ctx_p = &sec_ctx_stack[sec_ctx_stack_ndx];
387 /* Clear previous user info */
389 ctx_p->ut.uid = (uid_t)-1;
390 ctx_p->ut.gid = (gid_t)-1;
392 SAFE_FREE(ctx_p->ut.groups);
393 ctx_p->ut.ngroups = 0;
395 TALLOC_FREE(ctx_p->token);
397 /* Pop back previous user */
399 sec_ctx_stack_ndx--;
401 prev_ctx_p = &sec_ctx_stack[sec_ctx_stack_ndx];
403 /* Change uid, gid and supplementary group list. */
404 set_unix_security_ctx(prev_ctx_p->ut.uid,
405 prev_ctx_p->ut.gid,
406 prev_ctx_p->ut.ngroups,
407 prev_ctx_p->ut.groups);
409 /* Update current_user stuff */
411 current_user.ut.uid = prev_ctx_p->ut.uid;
412 current_user.ut.gid = prev_ctx_p->ut.gid;
413 current_user.ut.ngroups = prev_ctx_p->ut.ngroups;
414 current_user.ut.groups = prev_ctx_p->ut.groups;
415 current_user.nt_user_token = prev_ctx_p->token;
417 DEBUG(3, ("pop_sec_ctx (%u, %u) - sec_ctx_stack_ndx = %d\n",
418 (unsigned int)geteuid(), (unsigned int)getegid(), sec_ctx_stack_ndx));
420 return True;
423 /* Initialise the security context system */
425 void init_sec_ctx(void)
427 int i;
428 struct sec_ctx *ctx_p;
430 /* Initialise security context stack */
432 memset(sec_ctx_stack, 0, sizeof(struct sec_ctx) * MAX_SEC_CTX_DEPTH);
434 for (i = 0; i < MAX_SEC_CTX_DEPTH; i++) {
435 sec_ctx_stack[i].ut.uid = (uid_t)-1;
436 sec_ctx_stack[i].ut.gid = (gid_t)-1;
439 /* Initialise first level of stack. It is the current context */
440 ctx_p = &sec_ctx_stack[0];
442 ctx_p->ut.uid = geteuid();
443 ctx_p->ut.gid = getegid();
445 get_current_groups(ctx_p->ut.gid, &ctx_p->ut.ngroups, &ctx_p->ut.groups);
447 ctx_p->token = NULL; /* Maps to guest user. */
449 /* Initialise current_user global */
451 current_user.ut.uid = ctx_p->ut.uid;
452 current_user.ut.gid = ctx_p->ut.gid;
453 current_user.ut.ngroups = ctx_p->ut.ngroups;
454 current_user.ut.groups = ctx_p->ut.groups;
456 /* The conn and vuid are usually taken care of by other modules.
457 We initialise them here. */
459 current_user.conn = NULL;
460 current_user.vuid = UID_FIELD_INVALID;
461 current_user.nt_user_token = NULL;