Line data Source code
1 : /*
2 : * Zebra privileges.
3 : *
4 : * Copyright (C) 2003 Paul Jakma.
5 : * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
6 : *
7 : * This file is part of GNU Zebra.
8 : *
9 : * GNU Zebra is free software; you can redistribute it and/or modify it
10 : * under the terms of the GNU General Public License as published by the
11 : * Free Software Foundation; either version 2, or (at your option) any
12 : * later version.
13 : *
14 : * GNU Zebra is distributed in the hope that it will be useful, but
15 : * WITHOUT ANY WARRANTY; without even the implied warranty of
16 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 : * General Public License for more details.
18 : *
19 : * You should have received a copy of the GNU General Public License along
20 : * with this program; see the file COPYING; if not, write to the Free Software
21 : * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 : */
23 : #include <zebra.h>
24 : #include "log.h"
25 : #include "privs.h"
26 : #include "memory.h"
27 : #include "frr_pthread.h"
28 : #include "lib_errors.h"
29 : #include "lib/queue.h"
30 :
31 27 : DEFINE_MTYPE_STATIC(LIB, PRIVS, "Privilege information");
32 :
33 : /*
34 : * Different capabilities/privileges apis have different characteristics: some
35 : * are process-wide, and some are per-thread.
36 : */
37 : #ifdef HAVE_CAPABILITIES
38 : #ifdef HAVE_LCAPS
39 : static const bool privs_per_process; /* = false */
40 : #else
41 : static const bool privs_per_process = true;
42 : #endif /* HAVE_LCAPS */
43 : #else /* HAVE_CAPABILITIES */
44 : static const bool privs_per_process = true;
45 : #endif
46 :
47 : #ifdef HAVE_CAPABILITIES
48 :
49 : /* sort out some generic internal types for:
50 : *
51 : * privilege values (cap_value_t, priv_t) -> pvalue_t
52 : * privilege set (..., priv_set_t) -> pset_t
53 : * privilege working storage (cap_t, ...) -> pstorage_t
54 : *
55 : * values we think of as numeric (they're ints really, but we dont know)
56 : * sets are mostly opaque, to hold a set of privileges, related in some way.
57 : * storage binds together a set of sets we're interested in.
58 : * (in reality: cap_value_t and priv_t are ints)
59 : */
60 : #ifdef HAVE_LCAPS
61 : /* Linux doesn't have a 'set' type: a set of related privileges */
62 : struct _pset {
63 : int num;
64 : cap_value_t *caps;
65 : };
66 : typedef cap_value_t pvalue_t;
67 : typedef struct _pset pset_t;
68 : typedef cap_t pstorage_t;
69 :
70 : #else /* no LCAPS */
71 : #error "HAVE_CAPABILITIES defined, but neither LCAPS nor Solaris Capabilties!"
72 : #endif /* HAVE_LCAPS */
73 : #endif /* HAVE_CAPABILITIES */
74 :
75 : /* the default NULL state we report is RAISED, but could be LOWERED if
76 : * zprivs_terminate is called and the NULL handler is installed.
77 : */
78 : static zebra_privs_current_t zprivs_null_state = ZPRIVS_RAISED;
79 :
80 : /* internal privileges state */
81 : static struct _zprivs_t {
82 : #ifdef HAVE_CAPABILITIES
83 : pstorage_t caps; /* working storage */
84 : pset_t *syscaps_p; /* system-type requested permitted caps */
85 : pset_t *syscaps_i; /* system-type requested inheritable caps */
86 : #endif /* HAVE_CAPABILITIES */
87 : uid_t zuid, /* uid to run as */
88 : zsuid; /* saved uid */
89 : gid_t zgid; /* gid to run as */
90 : gid_t vtygrp; /* gid for vty sockets */
91 : } zprivs_state;
92 :
93 : /* externally exported but not directly accessed functions */
94 : #ifdef HAVE_CAPABILITIES
95 : int zprivs_change_caps(zebra_privs_ops_t);
96 : zebra_privs_current_t zprivs_state_caps(void);
97 : #endif /* HAVE_CAPABILITIES */
98 : int zprivs_change_uid(zebra_privs_ops_t);
99 : zebra_privs_current_t zprivs_state_uid(void);
100 : int zprivs_change_null(zebra_privs_ops_t);
101 : zebra_privs_current_t zprivs_state_null(void);
102 :
103 : #ifdef HAVE_CAPABILITIES
104 : /* internal capability API */
105 : static pset_t *zcaps2sys(zebra_capabilities_t *, int);
106 : static void zprivs_caps_init(struct zebra_privs_t *);
107 : static void zprivs_caps_terminate(void);
108 :
109 : /* Map of Quagga abstract capabilities to system capabilities */
110 : static struct {
111 : int num;
112 : pvalue_t *system_caps;
113 : } cap_map[ZCAP_MAX] = {
114 : #ifdef HAVE_LCAPS /* Quagga -> Linux capabilities mappings */
115 : [ZCAP_SETID] =
116 : {
117 : 2, (pvalue_t[]){CAP_SETGID, CAP_SETUID},
118 : },
119 : [ZCAP_BIND] =
120 : {
121 : 1, (pvalue_t[]){CAP_NET_BIND_SERVICE},
122 : },
123 : [ZCAP_NET_ADMIN] =
124 : {
125 : 1, (pvalue_t[]){CAP_NET_ADMIN},
126 : },
127 : [ZCAP_NET_RAW] =
128 : {
129 : 1, (pvalue_t[]){CAP_NET_RAW},
130 : },
131 : [ZCAP_CHROOT] =
132 : {
133 : 1,
134 : (pvalue_t[]){
135 : CAP_SYS_CHROOT,
136 : },
137 : },
138 : [ZCAP_NICE] =
139 : {
140 : 1, (pvalue_t[]){CAP_SYS_NICE},
141 : },
142 : [ZCAP_PTRACE] =
143 : {
144 : 1, (pvalue_t[]){CAP_SYS_PTRACE},
145 : },
146 : [ZCAP_DAC_OVERRIDE] =
147 : {
148 : 1, (pvalue_t[]){CAP_DAC_OVERRIDE},
149 : },
150 : [ZCAP_READ_SEARCH] =
151 : {
152 : 1, (pvalue_t[]){CAP_DAC_READ_SEARCH},
153 : },
154 : [ZCAP_SYS_ADMIN] =
155 : {
156 : 1, (pvalue_t[]){CAP_SYS_ADMIN},
157 : },
158 : [ZCAP_FOWNER] =
159 : {
160 : 1, (pvalue_t[]){CAP_FOWNER},
161 : },
162 : [ZCAP_IPC_LOCK] =
163 : {
164 : 1, (pvalue_t[]){CAP_IPC_LOCK},
165 : },
166 : [ZCAP_SYS_RAWIO] =
167 : {
168 : 1, (pvalue_t[]){CAP_SYS_RAWIO},
169 : },
170 : #endif /* HAVE_LCAPS */
171 : };
172 :
173 : #ifdef HAVE_LCAPS
174 : /* Linux forms of capabilities methods */
175 : /* convert zebras privileges to system capabilities */
176 18 : static pset_t *zcaps2sys(zebra_capabilities_t *zcaps, int num)
177 : {
178 18 : pset_t *syscaps;
179 18 : int i, j = 0, count = 0;
180 :
181 18 : if (!num)
182 : return NULL;
183 :
184 : /* first count up how many system caps we have */
185 27 : for (i = 0; i < num; i++)
186 21 : count += cap_map[zcaps[i]].num;
187 :
188 6 : if ((syscaps = XCALLOC(MTYPE_PRIVS, (sizeof(pset_t) * num))) == NULL) {
189 : fprintf(stderr, "%s: could not allocate syscaps!", __func__);
190 : return NULL;
191 : }
192 :
193 6 : syscaps->caps = XCALLOC(MTYPE_PRIVS, (sizeof(pvalue_t) * count));
194 :
195 6 : if (!syscaps->caps) {
196 : fprintf(stderr, "%s: could not XCALLOC caps!", __func__);
197 : return NULL;
198 : }
199 :
200 : /* copy the capabilities over */
201 : count = 0;
202 27 : for (i = 0; i < num; i++)
203 42 : for (j = 0; j < cap_map[zcaps[i]].num; j++)
204 21 : syscaps->caps[count++] =
205 21 : cap_map[zcaps[i]].system_caps[j];
206 :
207 : /* iterations above should be exact same as previous count, obviously..
208 : */
209 6 : syscaps->num = count;
210 :
211 6 : return syscaps;
212 : }
213 :
214 : /* set or clear the effective capabilities to/from permitted */
215 308 : int zprivs_change_caps(zebra_privs_ops_t op)
216 : {
217 308 : cap_flag_value_t cflag;
218 :
219 : /* should be no possibility of being called without valid caps */
220 308 : assert(zprivs_state.syscaps_p && zprivs_state.caps);
221 308 : if (!(zprivs_state.syscaps_p && zprivs_state.caps))
222 0 : exit(1);
223 :
224 308 : if (op == ZPRIVS_RAISE)
225 : cflag = CAP_SET;
226 154 : else if (op == ZPRIVS_LOWER)
227 : cflag = CAP_CLEAR;
228 : else
229 : return -1;
230 :
231 308 : if (!cap_set_flag(zprivs_state.caps, CAP_EFFECTIVE,
232 : zprivs_state.syscaps_p->num,
233 308 : zprivs_state.syscaps_p->caps, cflag))
234 308 : return cap_set_proc(zprivs_state.caps);
235 : return -1;
236 : }
237 :
238 0 : zebra_privs_current_t zprivs_state_caps(void)
239 : {
240 0 : int i;
241 0 : cap_flag_value_t val;
242 :
243 : /* should be no possibility of being called without valid caps */
244 0 : assert(zprivs_state.syscaps_p && zprivs_state.caps);
245 0 : if (!(zprivs_state.syscaps_p && zprivs_state.caps))
246 0 : exit(1);
247 :
248 0 : for (i = 0; i < zprivs_state.syscaps_p->num; i++) {
249 0 : if (cap_get_flag(zprivs_state.caps,
250 0 : zprivs_state.syscaps_p->caps[i], CAP_EFFECTIVE,
251 : &val)) {
252 0 : flog_err(
253 : EC_LIB_SYSTEM_CALL,
254 : "zprivs_state_caps: could not cap_get_flag, %s",
255 : safe_strerror(errno));
256 0 : return ZPRIVS_UNKNOWN;
257 : }
258 0 : if (val == CAP_SET)
259 : return ZPRIVS_RAISED;
260 : }
261 : return ZPRIVS_LOWERED;
262 : }
263 :
264 : /** Release private cap state if allocated. */
265 18 : static void zprivs_state_free_caps(void)
266 : {
267 18 : if (zprivs_state.syscaps_p) {
268 6 : if (zprivs_state.syscaps_p->num)
269 6 : XFREE(MTYPE_PRIVS, zprivs_state.syscaps_p->caps);
270 :
271 6 : XFREE(MTYPE_PRIVS, zprivs_state.syscaps_p);
272 : }
273 :
274 18 : if (zprivs_state.syscaps_i) {
275 0 : if (zprivs_state.syscaps_i->num)
276 0 : XFREE(MTYPE_PRIVS, zprivs_state.syscaps_i->caps);
277 :
278 0 : XFREE(MTYPE_PRIVS, zprivs_state.syscaps_i);
279 : }
280 :
281 18 : if (zprivs_state.caps) {
282 9 : cap_free(zprivs_state.caps);
283 9 : zprivs_state.caps = NULL;
284 : }
285 18 : }
286 :
287 9 : static void zprivs_caps_init(struct zebra_privs_t *zprivs)
288 : {
289 : /* Release allocated zcaps if this function was called before. */
290 9 : zprivs_state_free_caps();
291 :
292 9 : zprivs_state.syscaps_p = zcaps2sys(zprivs->caps_p, zprivs->cap_num_p);
293 9 : zprivs_state.syscaps_i = zcaps2sys(zprivs->caps_i, zprivs->cap_num_i);
294 :
295 : /* Tell kernel we want caps maintained across uid changes */
296 9 : if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) {
297 0 : fprintf(stderr,
298 : "privs_init: could not set PR_SET_KEEPCAPS, %s\n",
299 0 : safe_strerror(errno));
300 0 : exit(1);
301 : }
302 :
303 : /* we have caps, we have no need to ever change back the original user
304 : */
305 : /* only change uid if we don't have the correct one */
306 9 : if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) {
307 0 : if (setreuid(zprivs_state.zuid, zprivs_state.zuid)) {
308 0 : fprintf(stderr,
309 : "zprivs_init (cap): could not setreuid, %s\n",
310 0 : safe_strerror(errno));
311 0 : exit(1);
312 : }
313 : }
314 :
315 9 : if (!(zprivs_state.caps = cap_init())) {
316 0 : fprintf(stderr, "privs_init: failed to cap_init, %s\n",
317 0 : safe_strerror(errno));
318 0 : exit(1);
319 : }
320 :
321 9 : if (cap_clear(zprivs_state.caps)) {
322 0 : fprintf(stderr, "privs_init: failed to cap_clear, %s\n",
323 0 : safe_strerror(errno));
324 0 : exit(1);
325 : }
326 :
327 : /* set permitted caps, if any */
328 9 : if (zprivs_state.syscaps_p && zprivs_state.syscaps_p->num) {
329 6 : cap_set_flag(zprivs_state.caps, CAP_PERMITTED,
330 : zprivs_state.syscaps_p->num,
331 6 : zprivs_state.syscaps_p->caps, CAP_SET);
332 : }
333 :
334 : /* set inheritable caps, if any */
335 9 : if (zprivs_state.syscaps_i && zprivs_state.syscaps_i->num) {
336 0 : cap_set_flag(zprivs_state.caps, CAP_INHERITABLE,
337 : zprivs_state.syscaps_i->num,
338 0 : zprivs_state.syscaps_i->caps, CAP_SET);
339 : }
340 :
341 : /* apply caps. CAP_EFFECTIVE is cleared. we'll raise the caps as
342 : * and when, and only when, they are needed.
343 : */
344 9 : if (cap_set_proc(zprivs_state.caps)) {
345 0 : cap_t current_caps;
346 0 : char *current_caps_text = NULL;
347 0 : char *wanted_caps_text = NULL;
348 :
349 0 : fprintf(stderr, "privs_init: initial cap_set_proc failed: %s\n",
350 0 : safe_strerror(errno));
351 :
352 0 : current_caps = cap_get_proc();
353 0 : if (current_caps) {
354 0 : current_caps_text = cap_to_text(current_caps, NULL);
355 0 : cap_free(current_caps);
356 : }
357 :
358 0 : wanted_caps_text = cap_to_text(zprivs_state.caps, NULL);
359 0 : fprintf(stderr, "Wanted caps: %s\n",
360 : wanted_caps_text ? wanted_caps_text : "???");
361 0 : fprintf(stderr, "Have caps: %s\n",
362 : current_caps_text ? current_caps_text : "???");
363 0 : if (current_caps_text)
364 0 : cap_free(current_caps_text);
365 0 : if (wanted_caps_text)
366 0 : cap_free(wanted_caps_text);
367 :
368 0 : exit(1);
369 : }
370 :
371 : /* set methods for the caller to use */
372 9 : zprivs->change = zprivs_change_caps;
373 9 : zprivs->current_state = zprivs_state_caps;
374 9 : }
375 :
376 9 : static void zprivs_caps_terminate(void)
377 : {
378 : /* Clear all capabilities, if we have any. */
379 9 : if (zprivs_state.caps)
380 9 : cap_clear(zprivs_state.caps);
381 : else
382 : return;
383 :
384 : /* and boom, capabilities are gone forever */
385 9 : if (cap_set_proc(zprivs_state.caps)) {
386 0 : fprintf(stderr, "privs_terminate: cap_set_proc failed, %s",
387 0 : safe_strerror(errno));
388 0 : exit(1);
389 : }
390 :
391 9 : zprivs_state_free_caps();
392 : }
393 : #else /* !HAVE_LCAPS */
394 : #error "no Linux capabilities, dazed and confused..."
395 : #endif /* HAVE_LCAPS */
396 : #endif /* HAVE_CAPABILITIES */
397 :
398 0 : int zprivs_change_uid(zebra_privs_ops_t op)
399 : {
400 0 : if (zprivs_state.zsuid == zprivs_state.zuid)
401 : return 0;
402 0 : if (op == ZPRIVS_RAISE)
403 0 : return seteuid(zprivs_state.zsuid);
404 0 : else if (op == ZPRIVS_LOWER)
405 0 : return seteuid(zprivs_state.zuid);
406 : else
407 : return -1;
408 : }
409 :
410 0 : zebra_privs_current_t zprivs_state_uid(void)
411 : {
412 0 : return ((zprivs_state.zuid == geteuid()) ? ZPRIVS_LOWERED
413 0 : : ZPRIVS_RAISED);
414 : }
415 :
416 0 : int zprivs_change_null(zebra_privs_ops_t op)
417 : {
418 0 : return 0;
419 : }
420 :
421 0 : zebra_privs_current_t zprivs_state_null(void)
422 : {
423 0 : return zprivs_null_state;
424 : }
425 :
426 : #ifndef HAVE_GETGROUPLIST
427 : /* Solaris 11 has no getgrouplist() */
428 : static int getgrouplist(const char *user, gid_t group, gid_t *groups,
429 : int *ngroups)
430 : {
431 : struct group *grp;
432 : size_t usridx;
433 : int pos = 0, ret;
434 :
435 : if (pos < *ngroups)
436 : groups[pos] = group;
437 : pos++;
438 :
439 : setgrent();
440 : while ((grp = getgrent())) {
441 : if (grp->gr_gid == group)
442 : continue;
443 : for (usridx = 0; grp->gr_mem[usridx] != NULL; usridx++)
444 : if (!strcmp(grp->gr_mem[usridx], user)) {
445 : if (pos < *ngroups)
446 : groups[pos] = grp->gr_gid;
447 : pos++;
448 : break;
449 : }
450 : }
451 : endgrent();
452 :
453 : ret = (pos <= *ngroups) ? pos : -1;
454 : *ngroups = pos;
455 : return ret;
456 : }
457 : #endif /* HAVE_GETGROUPLIST */
458 :
459 : /*
460 : * Helper function that locates a refcounting object to use: a process-wide
461 : * object or a per-pthread object.
462 : */
463 308 : static struct zebra_privs_refs_t *get_privs_refs(struct zebra_privs_t *privs)
464 : {
465 308 : struct zebra_privs_refs_t *temp, *refs = NULL;
466 308 : pthread_t tid;
467 :
468 308 : if (privs_per_process)
469 : refs = &(privs->process_refs);
470 : else {
471 : /* Locate - or create - the object for the current pthread. */
472 308 : tid = pthread_self();
473 :
474 338 : STAILQ_FOREACH(temp, &(privs->thread_refs), entry) {
475 329 : if (pthread_equal(temp->tid, tid)) {
476 : refs = temp;
477 : break;
478 : }
479 : }
480 :
481 : /* Need to create a new refcounting object. */
482 308 : if (refs == NULL) {
483 9 : refs = XCALLOC(MTYPE_PRIVS,
484 : sizeof(struct zebra_privs_refs_t));
485 9 : refs->tid = tid;
486 9 : STAILQ_INSERT_TAIL(&(privs->thread_refs), refs, entry);
487 : }
488 : }
489 :
490 308 : return refs;
491 : }
492 :
493 157 : struct zebra_privs_t *_zprivs_raise(struct zebra_privs_t *privs,
494 : const char *funcname)
495 : {
496 157 : int save_errno = errno;
497 157 : struct zebra_privs_refs_t *refs;
498 :
499 157 : if (!privs)
500 : return NULL;
501 :
502 : /*
503 : * Serialize 'raise' operations; particularly important for
504 : * OSes where privs are process-wide.
505 : */
506 308 : frr_with_mutex (&(privs->mutex)) {
507 : /* Locate ref-counting object to use */
508 154 : refs = get_privs_refs(privs);
509 :
510 154 : if (++(refs->refcount) == 1) {
511 154 : errno = 0;
512 154 : if (privs->change(ZPRIVS_RAISE)) {
513 0 : zlog_err("%s: Failed to raise privileges (%s)",
514 : funcname, safe_strerror(errno));
515 : }
516 154 : errno = save_errno;
517 154 : refs->raised_in_funcname = funcname;
518 : }
519 : }
520 :
521 154 : return privs;
522 : }
523 :
524 157 : void _zprivs_lower(struct zebra_privs_t **privs)
525 : {
526 157 : int save_errno = errno;
527 157 : struct zebra_privs_refs_t *refs;
528 :
529 157 : if (!*privs)
530 : return;
531 :
532 : /* Serialize 'lower privs' operation - particularly important
533 : * when OS privs are process-wide.
534 : */
535 308 : frr_with_mutex (&(*privs)->mutex) {
536 154 : refs = get_privs_refs(*privs);
537 :
538 154 : if (--(refs->refcount) == 0) {
539 154 : errno = 0;
540 154 : if ((*privs)->change(ZPRIVS_LOWER)) {
541 0 : zlog_err("%s: Failed to lower privileges (%s)",
542 : refs->raised_in_funcname,
543 : safe_strerror(errno));
544 : }
545 154 : errno = save_errno;
546 154 : refs->raised_in_funcname = NULL;
547 : }
548 : }
549 :
550 154 : *privs = NULL;
551 : }
552 :
553 9 : void zprivs_preinit(struct zebra_privs_t *zprivs)
554 : {
555 9 : struct passwd *pwentry = NULL;
556 9 : struct group *grentry = NULL;
557 :
558 9 : if (!zprivs) {
559 0 : fprintf(stderr, "zprivs_init: called with NULL arg!\n");
560 0 : exit(1);
561 : }
562 :
563 9 : pthread_mutex_init(&(zprivs->mutex), NULL);
564 9 : zprivs->process_refs.refcount = 0;
565 9 : zprivs->process_refs.raised_in_funcname = NULL;
566 9 : STAILQ_INIT(&zprivs->thread_refs);
567 :
568 9 : if (zprivs->vty_group) {
569 : /* in a "NULL" setup, this is allowed to fail too, but still
570 : * try. */
571 9 : if ((grentry = getgrnam(zprivs->vty_group)))
572 9 : zprivs_state.vtygrp = grentry->gr_gid;
573 : else
574 0 : zprivs_state.vtygrp = (gid_t)-1;
575 : }
576 :
577 : /* NULL privs */
578 9 : if (!(zprivs->user || zprivs->group || zprivs->cap_num_p
579 : || zprivs->cap_num_i)) {
580 0 : zprivs->change = zprivs_change_null;
581 0 : zprivs->current_state = zprivs_state_null;
582 0 : return;
583 : }
584 :
585 9 : if (zprivs->user) {
586 9 : if ((pwentry = getpwnam(zprivs->user)) == NULL) {
587 : /* cant use log.h here as it depends on vty */
588 0 : fprintf(stderr,
589 : "privs_init: could not lookup user %s\n",
590 : zprivs->user);
591 0 : exit(1);
592 : }
593 :
594 9 : zprivs_state.zuid = pwentry->pw_uid;
595 9 : zprivs_state.zgid = pwentry->pw_gid;
596 : }
597 :
598 9 : grentry = NULL;
599 :
600 9 : if (zprivs->group) {
601 9 : if ((grentry = getgrnam(zprivs->group)) == NULL) {
602 0 : fprintf(stderr,
603 : "privs_init: could not lookup group %s\n",
604 : zprivs->group);
605 0 : exit(1);
606 : }
607 :
608 9 : zprivs_state.zgid = grentry->gr_gid;
609 : }
610 : }
611 :
612 : struct zebra_privs_t *lib_privs;
613 :
614 9 : void zprivs_init(struct zebra_privs_t *zprivs)
615 : {
616 9 : gid_t groups[NGROUPS_MAX] = {};
617 9 : int i, ngroups = 0;
618 9 : int found = 0;
619 :
620 : /* NULL privs */
621 9 : if (!(zprivs->user || zprivs->group || zprivs->cap_num_p
622 : || zprivs->cap_num_i))
623 0 : return;
624 :
625 9 : lib_privs = zprivs;
626 :
627 9 : if (zprivs->user) {
628 9 : ngroups = array_size(groups);
629 9 : if (getgrouplist(zprivs->user, zprivs_state.zgid, groups,
630 : &ngroups)
631 : < 0) {
632 : /* cant use log.h here as it depends on vty */
633 0 : fprintf(stderr,
634 : "privs_init: could not getgrouplist for user %s\n",
635 : zprivs->user);
636 0 : exit(1);
637 : }
638 : }
639 :
640 9 : if (zprivs->vty_group)
641 : /* Add the vty_group to the supplementary groups so it can be chowned to
642 : */
643 : {
644 9 : if (zprivs_state.vtygrp == (gid_t)-1) {
645 0 : fprintf(stderr,
646 : "privs_init: could not lookup vty group %s\n",
647 : zprivs->vty_group);
648 0 : exit(1);
649 : }
650 :
651 9 : for (i = 0; i < ngroups; i++)
652 9 : if (groups[i] == zprivs_state.vtygrp) {
653 : found++;
654 : break;
655 : }
656 :
657 9 : if (!found) {
658 0 : fprintf(stderr,
659 : "privs_init: user(%s) is not part of vty group specified(%s)\n",
660 : zprivs->user, zprivs->vty_group);
661 0 : exit(1);
662 : }
663 9 : if (i >= ngroups && ngroups < (int)array_size(groups)) {
664 0 : groups[i] = zprivs_state.vtygrp;
665 : }
666 : }
667 :
668 9 : zprivs_state.zsuid = geteuid(); /* initial uid */
669 : /* add groups only if we changed uid - otherwise skip */
670 9 : if ((ngroups) && (zprivs_state.zsuid != zprivs_state.zuid)) {
671 0 : if (setgroups(ngroups, groups)) {
672 0 : fprintf(stderr, "privs_init: could not setgroups, %s\n",
673 0 : safe_strerror(errno));
674 0 : exit(1);
675 : }
676 : }
677 :
678 : /* change gid only if we changed uid - otherwise skip */
679 9 : if ((zprivs_state.zgid) && (zprivs_state.zsuid != zprivs_state.zuid)) {
680 : /* change group now, forever. uid we do later */
681 0 : if (setregid(zprivs_state.zgid, zprivs_state.zgid)) {
682 0 : fprintf(stderr, "zprivs_init: could not setregid, %s\n",
683 0 : safe_strerror(errno));
684 0 : exit(1);
685 : }
686 : }
687 :
688 : #ifdef HAVE_CAPABILITIES
689 9 : zprivs_caps_init(zprivs);
690 :
691 : /*
692 : * If we have initialized the system with no requested
693 : * capabilities, change will not have been set
694 : * to anything by zprivs_caps_init, As such
695 : * we should make sure that when we attempt
696 : * to raize privileges that we actually have
697 : * a do nothing function to call instead of a
698 : * crash :).
699 : */
700 9 : if (!zprivs->change)
701 0 : zprivs->change = zprivs_change_null;
702 :
703 : #else /* !HAVE_CAPABILITIES */
704 : /* we dont have caps. we'll need to maintain rid and saved uid
705 : * and change euid back to saved uid (who we presume has all necessary
706 : * privileges) whenever we are asked to raise our privileges.
707 : *
708 : * This is not worth that much security wise, but all we can do.
709 : */
710 : zprivs_state.zsuid = geteuid();
711 : /* only change uid if we don't have the correct one */
712 : if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) {
713 : if (setreuid(-1, zprivs_state.zuid)) {
714 : fprintf(stderr,
715 : "privs_init (uid): could not setreuid, %s\n",
716 : safe_strerror(errno));
717 : exit(1);
718 : }
719 : }
720 :
721 : zprivs->change = zprivs_change_uid;
722 : zprivs->current_state = zprivs_state_uid;
723 : #endif /* HAVE_CAPABILITIES */
724 : }
725 :
726 9 : void zprivs_terminate(struct zebra_privs_t *zprivs)
727 : {
728 9 : struct zebra_privs_refs_t *refs;
729 :
730 9 : lib_privs = NULL;
731 :
732 9 : if (!zprivs) {
733 0 : fprintf(stderr, "%s: no privs struct given, terminating",
734 : __func__);
735 0 : exit(0);
736 : }
737 :
738 : #ifdef HAVE_CAPABILITIES
739 9 : if (zprivs->user || zprivs->group || zprivs->cap_num_p
740 0 : || zprivs->cap_num_i)
741 9 : zprivs_caps_terminate();
742 : #else /* !HAVE_CAPABILITIES */
743 : /* only change uid if we don't have the correct one */
744 : if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) {
745 : if (setreuid(zprivs_state.zuid, zprivs_state.zuid)) {
746 : fprintf(stderr,
747 : "privs_terminate: could not setreuid, %s",
748 : safe_strerror(errno));
749 : exit(1);
750 : }
751 : }
752 : #endif /* HAVE_LCAPS */
753 :
754 18 : while ((refs = STAILQ_FIRST(&(zprivs->thread_refs))) != NULL) {
755 9 : STAILQ_REMOVE_HEAD(&(zprivs->thread_refs), entry);
756 18 : XFREE(MTYPE_PRIVS, refs);
757 : }
758 :
759 9 : zprivs->change = zprivs_change_null;
760 9 : zprivs->current_state = zprivs_state_null;
761 9 : zprivs_null_state = ZPRIVS_LOWERED;
762 9 : return;
763 : }
764 :
765 21 : void zprivs_get_ids(struct zprivs_ids_t *ids)
766 : {
767 :
768 21 : ids->uid_priv = getuid();
769 0 : (zprivs_state.zuid) ? (ids->uid_normal = zprivs_state.zuid)
770 21 : : (ids->uid_normal = (uid_t)-1);
771 0 : (zprivs_state.zgid) ? (ids->gid_normal = zprivs_state.zgid)
772 21 : : (ids->gid_normal = (uid_t)-1);
773 0 : (zprivs_state.vtygrp) ? (ids->gid_vty = zprivs_state.vtygrp)
774 21 : : (ids->gid_vty = (uid_t)-1);
775 :
776 21 : return;
777 : }
|
