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d62a17ae | 1 | /* |
01245821 | 2 | * Zebra privileges. |
3 | * | |
4 | * Copyright (C) 2003 Paul Jakma. | |
01070b9e | 5 | * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved. |
01245821 | 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 | * | |
896014f4 DL |
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 | |
01245821 | 22 | */ |
01245821 | 23 | #include <zebra.h> |
24 | #include "log.h" | |
25 | #include "privs.h" | |
26 | #include "memory.h" | |
ff245f0e | 27 | #include "lib_errors.h" |
01245821 | 28 | |
ceacedba | 29 | #ifdef HAVE_CAPABILITIES |
4a1ab8e4 DL |
30 | |
31 | DEFINE_MTYPE_STATIC(LIB, PRIVS, "Privilege information") | |
32 | ||
ceacedba | 33 | /* sort out some generic internal types for: |
34 | * | |
35 | * privilege values (cap_value_t, priv_t) -> pvalue_t | |
36 | * privilege set (..., priv_set_t) -> pset_t | |
37 | * privilege working storage (cap_t, ...) -> pstorage_t | |
38 | * | |
39 | * values we think of as numeric (they're ints really, but we dont know) | |
40 | * sets are mostly opaque, to hold a set of privileges, related in some way. | |
41 | * storage binds together a set of sets we're interested in. | |
42 | * (in reality: cap_value_t and priv_t are ints) | |
d62a17ae | 43 | */ |
ceacedba | 44 | #ifdef HAVE_LCAPS |
45 | /* Linux doesn't have a 'set' type: a set of related privileges */ | |
46 | struct _pset { | |
d62a17ae | 47 | int num; |
48 | cap_value_t *caps; | |
ceacedba | 49 | }; |
50 | typedef cap_value_t pvalue_t; | |
51 | typedef struct _pset pset_t; | |
52 | typedef cap_t pstorage_t; | |
6b0655a2 | 53 | |
d62a17ae | 54 | #elif defined(HAVE_SOLARIS_CAPABILITIES) |
ceacedba | 55 | typedef priv_t pvalue_t; |
56 | typedef priv_set_t pset_t; | |
57 | typedef priv_set_t *pstorage_t; | |
58 | #else /* neither LCAPS nor SOLARIS_CAPABILITIES */ | |
59 | #error "HAVE_CAPABILITIES defined, but neither LCAPS nor Solaris Capabilties!" | |
60 | #endif /* HAVE_LCAPS */ | |
61 | #endif /* HAVE_CAPABILITIES */ | |
6b0655a2 | 62 | |
ceacedba | 63 | /* the default NULL state we report is RAISED, but could be LOWERED if |
64 | * zprivs_terminate is called and the NULL handler is installed. | |
65 | */ | |
66 | static zebra_privs_current_t zprivs_null_state = ZPRIVS_RAISED; | |
67 | ||
01245821 | 68 | /* internal privileges state */ |
d62a17ae | 69 | static struct _zprivs_t { |
ceacedba | 70 | #ifdef HAVE_CAPABILITIES |
d62a17ae | 71 | pstorage_t caps; /* working storage */ |
72 | pset_t *syscaps_p; /* system-type requested permitted caps */ | |
73 | pset_t *syscaps_i; /* system-type requested inheritable caps */ | |
74 | #endif /* HAVE_CAPABILITIES */ | |
75 | uid_t zuid, /* uid to run as */ | |
76 | zsuid; /* saved uid */ | |
77 | gid_t zgid; /* gid to run as */ | |
78 | gid_t vtygrp; /* gid for vty sockets */ | |
01245821 | 79 | } zprivs_state; |
80 | ||
81 | /* externally exported but not directly accessed functions */ | |
ceacedba | 82 | #ifdef HAVE_CAPABILITIES |
d62a17ae | 83 | int zprivs_change_caps(zebra_privs_ops_t); |
84 | zebra_privs_current_t zprivs_state_caps(void); | |
ceacedba | 85 | #endif /* HAVE_CAPABILITIES */ |
d62a17ae | 86 | int zprivs_change_uid(zebra_privs_ops_t); |
87 | zebra_privs_current_t zprivs_state_uid(void); | |
88 | int zprivs_change_null(zebra_privs_ops_t); | |
89 | zebra_privs_current_t zprivs_state_null(void); | |
01245821 | 90 | |
ceacedba | 91 | #ifdef HAVE_CAPABILITIES |
92 | /* internal capability API */ | |
d62a17ae | 93 | static pset_t *zcaps2sys(zebra_capabilities_t *, int); |
94 | static void zprivs_caps_init(struct zebra_privs_t *); | |
95 | static void zprivs_caps_terminate(void); | |
ceacedba | 96 | |
97 | /* Map of Quagga abstract capabilities to system capabilities */ | |
d62a17ae | 98 | static struct { |
99 | int num; | |
100 | pvalue_t *system_caps; | |
101 | } cap_map[ZCAP_MAX] = { | |
ceacedba | 102 | #ifdef HAVE_LCAPS /* Quagga -> Linux capabilities mappings */ |
9d303b37 DL |
103 | [ZCAP_SETID] = |
104 | { | |
105 | 2, (pvalue_t[]){CAP_SETGID, CAP_SETUID}, | |
106 | }, | |
107 | [ZCAP_BIND] = | |
108 | { | |
109 | 1, (pvalue_t[]){CAP_NET_BIND_SERVICE}, | |
110 | }, | |
111 | [ZCAP_NET_ADMIN] = | |
112 | { | |
113 | 1, (pvalue_t[]){CAP_NET_ADMIN}, | |
114 | }, | |
115 | [ZCAP_NET_RAW] = | |
116 | { | |
117 | 1, (pvalue_t[]){CAP_NET_RAW}, | |
118 | }, | |
119 | [ZCAP_CHROOT] = | |
120 | { | |
121 | 1, | |
122 | (pvalue_t[]){ | |
123 | CAP_SYS_CHROOT, | |
124 | }, | |
125 | }, | |
126 | [ZCAP_NICE] = | |
127 | { | |
128 | 1, (pvalue_t[]){CAP_SYS_NICE}, | |
129 | }, | |
130 | [ZCAP_PTRACE] = | |
131 | { | |
132 | 1, (pvalue_t[]){CAP_SYS_PTRACE}, | |
133 | }, | |
134 | [ZCAP_DAC_OVERRIDE] = | |
135 | { | |
136 | 1, (pvalue_t[]){CAP_DAC_OVERRIDE}, | |
137 | }, | |
138 | [ZCAP_READ_SEARCH] = | |
139 | { | |
140 | 1, (pvalue_t[]){CAP_DAC_READ_SEARCH}, | |
141 | }, | |
142 | [ZCAP_SYS_ADMIN] = | |
143 | { | |
144 | 1, (pvalue_t[]){CAP_SYS_ADMIN}, | |
145 | }, | |
146 | [ZCAP_FOWNER] = | |
147 | { | |
148 | 1, (pvalue_t[]){CAP_FOWNER}, | |
d62a17ae | 149 | }, |
ceacedba | 150 | #elif defined(HAVE_SOLARIS_CAPABILITIES) /* HAVE_LCAPS */ |
9d303b37 DL |
151 | /* Quagga -> Solaris privilege mappings */ |
152 | [ZCAP_SETID] = | |
153 | { | |
154 | 1, (pvalue_t[]){PRIV_PROC_SETID}, | |
155 | }, | |
156 | [ZCAP_BIND] = | |
157 | { | |
158 | 1, (pvalue_t[]){PRIV_NET_PRIVADDR}, | |
159 | }, | |
d62a17ae | 160 | /* IP_CONFIG is a subset of NET_CONFIG and is allowed in zones */ |
6b148faa | 161 | #ifdef PRIV_SYS_IP_CONFIG |
9d303b37 DL |
162 | [ZCAP_NET_ADMIN] = |
163 | { | |
164 | 1, (pvalue_t[]){PRIV_SYS_IP_CONFIG}, | |
165 | }, | |
6b148faa | 166 | #else |
9d303b37 DL |
167 | [ZCAP_NET_ADMIN] = |
168 | { | |
169 | 1, (pvalue_t[]){PRIV_SYS_NET_CONFIG}, | |
170 | }, | |
6b148faa | 171 | #endif |
9d303b37 DL |
172 | [ZCAP_NET_RAW] = |
173 | { | |
174 | 2, (pvalue_t[]){PRIV_NET_RAWACCESS, | |
175 | PRIV_NET_ICMPACCESS}, | |
176 | }, | |
177 | [ZCAP_CHROOT] = | |
178 | { | |
179 | 1, (pvalue_t[]){PRIV_PROC_CHROOT}, | |
180 | }, | |
181 | [ZCAP_NICE] = | |
182 | { | |
183 | 1, (pvalue_t[]){PRIV_PROC_PRIOCNTL}, | |
184 | }, | |
185 | [ZCAP_PTRACE] = | |
186 | { | |
187 | 1, (pvalue_t[]){PRIV_PROC_SESSION}, | |
188 | }, | |
189 | [ZCAP_DAC_OVERRIDE] = | |
190 | { | |
191 | 5, (pvalue_t[]){PRIV_FILE_DAC_EXECUTE, | |
192 | PRIV_FILE_DAC_READ, | |
193 | PRIV_FILE_DAC_SEARCH, | |
194 | PRIV_FILE_DAC_WRITE, | |
195 | PRIV_FILE_DAC_SEARCH}, | |
196 | }, | |
197 | [ZCAP_READ_SEARCH] = | |
198 | { | |
199 | 2, (pvalue_t[]){PRIV_FILE_DAC_SEARCH, | |
200 | PRIV_FILE_DAC_READ}, | |
201 | }, | |
202 | [ZCAP_SYS_ADMIN] = | |
203 | { | |
204 | 1, (pvalue_t[]){PRIV_SYS_ADMIN}, | |
205 | }, | |
206 | [ZCAP_FOWNER] = | |
207 | { | |
208 | 1, (pvalue_t[]){PRIV_FILE_OWNER}, | |
209 | }, | |
ceacedba | 210 | #endif /* HAVE_SOLARIS_CAPABILITIES */ |
01245821 | 211 | }; |
6b0655a2 | 212 | |
ceacedba | 213 | #ifdef HAVE_LCAPS |
214 | /* Linux forms of capabilities methods */ | |
01245821 | 215 | /* convert zebras privileges to system capabilities */ |
d62a17ae | 216 | static pset_t *zcaps2sys(zebra_capabilities_t *zcaps, int num) |
01245821 | 217 | { |
d62a17ae | 218 | pset_t *syscaps; |
219 | int i, j = 0, count = 0; | |
220 | ||
221 | if (!num) | |
222 | return NULL; | |
223 | ||
224 | /* first count up how many system caps we have */ | |
225 | for (i = 0; i < num; i++) | |
226 | count += cap_map[zcaps[i]].num; | |
227 | ||
228 | if ((syscaps = XCALLOC(MTYPE_PRIVS, (sizeof(pset_t) * num))) == NULL) { | |
229 | fprintf(stderr, "%s: could not allocate syscaps!", __func__); | |
230 | return NULL; | |
231 | } | |
232 | ||
233 | syscaps->caps = XCALLOC(MTYPE_PRIVS, (sizeof(pvalue_t) * count)); | |
234 | ||
235 | if (!syscaps->caps) { | |
236 | fprintf(stderr, "%s: could not XCALLOC caps!", __func__); | |
237 | return NULL; | |
238 | } | |
239 | ||
240 | /* copy the capabilities over */ | |
241 | count = 0; | |
242 | for (i = 0; i < num; i++) | |
243 | for (j = 0; j < cap_map[zcaps[i]].num; j++) | |
244 | syscaps->caps[count++] = | |
245 | cap_map[zcaps[i]].system_caps[j]; | |
246 | ||
247 | /* iterations above should be exact same as previous count, obviously.. | |
248 | */ | |
249 | syscaps->num = count; | |
250 | ||
251 | return syscaps; | |
01245821 | 252 | } |
253 | ||
254 | /* set or clear the effective capabilities to/from permitted */ | |
d62a17ae | 255 | int zprivs_change_caps(zebra_privs_ops_t op) |
01245821 | 256 | { |
d62a17ae | 257 | cap_flag_value_t cflag; |
258 | ||
259 | /* should be no possibility of being called without valid caps */ | |
260 | assert(zprivs_state.syscaps_p && zprivs_state.caps); | |
261 | if (!(zprivs_state.syscaps_p && zprivs_state.caps)) | |
262 | exit(1); | |
263 | ||
264 | if (op == ZPRIVS_RAISE) | |
265 | cflag = CAP_SET; | |
266 | else if (op == ZPRIVS_LOWER) | |
267 | cflag = CAP_CLEAR; | |
268 | else | |
269 | return -1; | |
270 | ||
271 | if (!cap_set_flag(zprivs_state.caps, CAP_EFFECTIVE, | |
272 | zprivs_state.syscaps_p->num, | |
273 | zprivs_state.syscaps_p->caps, cflag)) | |
274 | return cap_set_proc(zprivs_state.caps); | |
275 | return -1; | |
01245821 | 276 | } |
277 | ||
d62a17ae | 278 | zebra_privs_current_t zprivs_state_caps(void) |
01245821 | 279 | { |
d62a17ae | 280 | int i; |
281 | cap_flag_value_t val; | |
282 | ||
283 | /* should be no possibility of being called without valid caps */ | |
284 | assert(zprivs_state.syscaps_p && zprivs_state.caps); | |
285 | if (!(zprivs_state.syscaps_p && zprivs_state.caps)) | |
286 | exit(1); | |
287 | ||
288 | for (i = 0; i < zprivs_state.syscaps_p->num; i++) { | |
289 | if (cap_get_flag(zprivs_state.caps, | |
290 | zprivs_state.syscaps_p->caps[i], CAP_EFFECTIVE, | |
291 | &val)) { | |
ff245f0e | 292 | flog_err( |
450971aa | 293 | EC_LIB_SYSTEM_CALL, |
d62a17ae | 294 | "zprivs_state_caps: could not cap_get_flag, %s", |
295 | safe_strerror(errno)); | |
296 | return ZPRIVS_UNKNOWN; | |
297 | } | |
298 | if (val == CAP_SET) | |
299 | return ZPRIVS_RAISED; | |
300 | } | |
301 | return ZPRIVS_LOWERED; | |
01245821 | 302 | } |
303 | ||
d62a17ae | 304 | static void zprivs_caps_init(struct zebra_privs_t *zprivs) |
ceacedba | 305 | { |
d62a17ae | 306 | zprivs_state.syscaps_p = zcaps2sys(zprivs->caps_p, zprivs->cap_num_p); |
307 | zprivs_state.syscaps_i = zcaps2sys(zprivs->caps_i, zprivs->cap_num_i); | |
308 | ||
309 | /* Tell kernel we want caps maintained across uid changes */ | |
310 | if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) { | |
311 | fprintf(stderr, | |
312 | "privs_init: could not set PR_SET_KEEPCAPS, %s\n", | |
313 | safe_strerror(errno)); | |
314 | exit(1); | |
315 | } | |
316 | ||
317 | /* we have caps, we have no need to ever change back the original user | |
318 | */ | |
319 | /* only change uid if we don't have the correct one */ | |
320 | if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) { | |
321 | if (setreuid(zprivs_state.zuid, zprivs_state.zuid)) { | |
322 | fprintf(stderr, | |
323 | "zprivs_init (cap): could not setreuid, %s\n", | |
324 | safe_strerror(errno)); | |
325 | exit(1); | |
326 | } | |
327 | } | |
328 | ||
329 | if (!zprivs_state.syscaps_p) | |
330 | return; | |
331 | ||
332 | if (!(zprivs_state.caps = cap_init())) { | |
333 | fprintf(stderr, "privs_init: failed to cap_init, %s\n", | |
334 | safe_strerror(errno)); | |
335 | exit(1); | |
336 | } | |
337 | ||
338 | if (cap_clear(zprivs_state.caps)) { | |
339 | fprintf(stderr, "privs_init: failed to cap_clear, %s\n", | |
340 | safe_strerror(errno)); | |
341 | exit(1); | |
342 | } | |
343 | ||
344 | /* set permitted caps */ | |
345 | cap_set_flag(zprivs_state.caps, CAP_PERMITTED, | |
346 | zprivs_state.syscaps_p->num, zprivs_state.syscaps_p->caps, | |
347 | CAP_SET); | |
348 | ||
349 | /* set inheritable caps, if any */ | |
350 | if (zprivs_state.syscaps_i && zprivs_state.syscaps_i->num) { | |
351 | cap_set_flag(zprivs_state.caps, CAP_INHERITABLE, | |
352 | zprivs_state.syscaps_i->num, | |
353 | zprivs_state.syscaps_i->caps, CAP_SET); | |
354 | } | |
355 | ||
356 | /* apply caps. CAP_EFFECTIVE is cleared. we'll raise the caps as | |
357 | * and when, and only when, they are needed. | |
358 | */ | |
359 | if (cap_set_proc(zprivs_state.caps)) { | |
360 | cap_t current_caps; | |
361 | char *current_caps_text = NULL; | |
362 | char *wanted_caps_text = NULL; | |
363 | ||
364 | fprintf(stderr, "privs_init: initial cap_set_proc failed: %s\n", | |
365 | safe_strerror(errno)); | |
366 | ||
367 | current_caps = cap_get_proc(); | |
368 | if (current_caps) { | |
369 | current_caps_text = cap_to_text(current_caps, NULL); | |
370 | cap_free(current_caps); | |
371 | } | |
372 | ||
373 | wanted_caps_text = cap_to_text(zprivs_state.caps, NULL); | |
374 | fprintf(stderr, "Wanted caps: %s\n", | |
375 | wanted_caps_text ? wanted_caps_text : "???"); | |
376 | fprintf(stderr, "Have caps: %s\n", | |
377 | current_caps_text ? current_caps_text : "???"); | |
378 | if (current_caps_text) | |
379 | cap_free(current_caps_text); | |
380 | if (wanted_caps_text) | |
381 | cap_free(wanted_caps_text); | |
382 | ||
383 | exit(1); | |
384 | } | |
385 | ||
386 | /* set methods for the caller to use */ | |
387 | zprivs->change = zprivs_change_caps; | |
388 | zprivs->current_state = zprivs_state_caps; | |
ceacedba | 389 | } |
390 | ||
d62a17ae | 391 | static void zprivs_caps_terminate(void) |
ceacedba | 392 | { |
d62a17ae | 393 | /* clear all capabilities */ |
394 | if (zprivs_state.caps) | |
395 | cap_clear(zprivs_state.caps); | |
396 | ||
397 | /* and boom, capabilities are gone forever */ | |
398 | if (cap_set_proc(zprivs_state.caps)) { | |
399 | fprintf(stderr, "privs_terminate: cap_set_proc failed, %s", | |
400 | safe_strerror(errno)); | |
401 | exit(1); | |
402 | } | |
403 | ||
404 | /* free up private state */ | |
405 | if (zprivs_state.syscaps_p->num) { | |
406 | XFREE(MTYPE_PRIVS, zprivs_state.syscaps_p->caps); | |
407 | XFREE(MTYPE_PRIVS, zprivs_state.syscaps_p); | |
408 | } | |
409 | ||
410 | if (zprivs_state.syscaps_i && zprivs_state.syscaps_i->num) { | |
411 | XFREE(MTYPE_PRIVS, zprivs_state.syscaps_i->caps); | |
412 | XFREE(MTYPE_PRIVS, zprivs_state.syscaps_i); | |
413 | } | |
414 | ||
415 | cap_free(zprivs_state.caps); | |
ceacedba | 416 | } |
d62a17ae | 417 | #elif defined(HAVE_SOLARIS_CAPABILITIES) /* !HAVE_LCAPS */ |
6b0655a2 | 418 | |
d62a17ae | 419 | /* Solaris specific capability/privilege methods |
ceacedba | 420 | * |
421 | * Resources: | |
422 | * - the 'privileges' man page | |
423 | * - http://cvs.opensolaris.org | |
d62a17ae | 424 | * - |
425 | * http://blogs.sun.com/roller/page/gbrunett?entry=privilege_enabling_set_id_programs1 | |
ceacedba | 426 | */ |
427 | ||
d62a17ae | 428 | static pset_t *zprivs_caps_minimal() |
01070b9e | 429 | { |
d62a17ae | 430 | pset_t *minimal; |
01070b9e | 431 | |
d62a17ae | 432 | if ((minimal = priv_str_to_set("basic", ",", NULL)) == NULL) { |
433 | fprintf(stderr, "%s: couldn't get basic set!\n", __func__); | |
434 | exit(1); | |
435 | } | |
01070b9e | 436 | |
d62a17ae | 437 | /* create a minimal privilege set from the basic set */ |
438 | (void)priv_delset(minimal, PRIV_PROC_EXEC); | |
439 | (void)priv_delset(minimal, PRIV_PROC_INFO); | |
440 | (void)priv_delset(minimal, PRIV_PROC_SESSION); | |
441 | (void)priv_delset(minimal, PRIV_FILE_LINK_ANY); | |
01070b9e | 442 | |
d62a17ae | 443 | return minimal; |
01070b9e BB |
444 | } |
445 | ||
ceacedba | 446 | /* convert zebras privileges to system capabilities */ |
d62a17ae | 447 | static pset_t *zcaps2sys(zebra_capabilities_t *zcaps, int num) |
ceacedba | 448 | { |
d62a17ae | 449 | pset_t *syscaps; |
450 | int i, j = 0; | |
451 | ||
452 | if ((syscaps = priv_allocset()) == NULL) { | |
453 | fprintf(stderr, "%s: could not allocate syscaps!\n", __func__); | |
454 | exit(1); | |
455 | } | |
456 | ||
457 | priv_emptyset(syscaps); | |
458 | ||
459 | for (i = 0; i < num; i++) | |
460 | for (j = 0; j < cap_map[zcaps[i]].num; j++) | |
461 | priv_addset(syscaps, cap_map[zcaps[i]].system_caps[j]); | |
462 | ||
463 | return syscaps; | |
ceacedba | 464 | } |
465 | ||
466 | /* callback exported to users to RAISE and LOWER effective privileges | |
467 | * from nothing to the given permitted set and back down | |
468 | */ | |
d62a17ae | 469 | int zprivs_change_caps(zebra_privs_ops_t op) |
ceacedba | 470 | { |
d62a17ae | 471 | pset_t *privset; |
472 | ||
473 | /* should be no possibility of being called without valid caps */ | |
474 | assert(zprivs_state.syscaps_p); | |
475 | if (!zprivs_state.syscaps_p) { | |
476 | fprintf(stderr, "%s: Eek, missing privileged caps!", __func__); | |
477 | exit(1); | |
478 | } | |
479 | ||
480 | assert(zprivs_state.caps); | |
481 | if (!zprivs_state.caps) { | |
482 | fprintf(stderr, "%s: Eek, missing caps!", __func__); | |
483 | exit(1); | |
484 | } | |
485 | ||
486 | /* to raise: copy original permitted as our working effective set | |
487 | * to lower: copy regular effective set stored in zprivs_state.caps | |
488 | */ | |
489 | if (op == ZPRIVS_RAISE) | |
490 | privset = zprivs_state.syscaps_p; | |
491 | else if (op == ZPRIVS_LOWER) | |
492 | privset = zprivs_state.caps; | |
493 | else | |
494 | return -1; | |
495 | ||
496 | if (setppriv(PRIV_SET, PRIV_EFFECTIVE, privset) != 0) | |
497 | return -1; | |
498 | ||
499 | return 0; | |
ceacedba | 500 | } |
501 | ||
502 | /* Retrieve current privilege state, is it RAISED or LOWERED? */ | |
d62a17ae | 503 | zebra_privs_current_t zprivs_state_caps(void) |
ceacedba | 504 | { |
d62a17ae | 505 | zebra_privs_current_t result; |
506 | pset_t *effective; | |
507 | ||
508 | if ((effective = priv_allocset()) == NULL) { | |
509 | fprintf(stderr, "%s: failed to get priv_allocset! %s\n", | |
510 | __func__, safe_strerror(errno)); | |
511 | return ZPRIVS_UNKNOWN; | |
512 | } | |
513 | ||
514 | if (getppriv(PRIV_EFFECTIVE, effective)) { | |
515 | fprintf(stderr, "%s: failed to get state! %s\n", __func__, | |
516 | safe_strerror(errno)); | |
517 | result = ZPRIVS_UNKNOWN; | |
518 | } else { | |
519 | if (priv_isequalset(effective, zprivs_state.syscaps_p)) | |
520 | result = ZPRIVS_RAISED; | |
521 | else if (priv_isequalset(effective, zprivs_state.caps)) | |
522 | result = ZPRIVS_LOWERED; | |
523 | else | |
524 | result = ZPRIVS_UNKNOWN; | |
525 | } | |
526 | ||
527 | priv_freeset(effective); | |
528 | return result; | |
ceacedba | 529 | } |
530 | ||
d62a17ae | 531 | static void zprivs_caps_init(struct zebra_privs_t *zprivs) |
ceacedba | 532 | { |
d62a17ae | 533 | pset_t *basic; |
534 | pset_t *minimal; | |
535 | ||
536 | /* the specified sets */ | |
537 | zprivs_state.syscaps_p = zcaps2sys(zprivs->caps_p, zprivs->cap_num_p); | |
538 | zprivs_state.syscaps_i = zcaps2sys(zprivs->caps_i, zprivs->cap_num_i); | |
539 | ||
540 | /* nonsensical to have gotten here but not have capabilities */ | |
541 | if (!zprivs_state.syscaps_p) { | |
542 | fprintf(stderr, | |
543 | "%s: capabilities enabled, " | |
544 | "but no valid capabilities supplied\n", | |
545 | __func__); | |
546 | } | |
547 | ||
548 | /* We retain the basic set in our permitted set, as Linux has no | |
549 | * equivalent. The basic set on Linux hence is implicit, always | |
550 | * there. | |
551 | */ | |
552 | if ((basic = priv_str_to_set("basic", ",", NULL)) == NULL) { | |
553 | fprintf(stderr, "%s: couldn't get basic set!\n", __func__); | |
554 | exit(1); | |
555 | } | |
556 | ||
557 | /* Add the basic set to the permitted set */ | |
558 | priv_union(basic, zprivs_state.syscaps_p); | |
559 | priv_freeset(basic); | |
560 | ||
561 | /* Hey kernel, we know about privileges! | |
562 | * this isn't strictly required, use of setppriv should have same effect | |
563 | */ | |
564 | if (setpflags(PRIV_AWARE, 1)) { | |
565 | fprintf(stderr, "%s: error setting PRIV_AWARE!, %s\n", __func__, | |
566 | safe_strerror(errno)); | |
567 | exit(1); | |
568 | } | |
569 | ||
570 | /* need either valid or empty sets for both p and i.. */ | |
571 | assert(zprivs_state.syscaps_i && zprivs_state.syscaps_p); | |
572 | ||
573 | /* we have caps, we have no need to ever change back the original user | |
574 | * change real, effective and saved to the specified user. | |
575 | */ | |
576 | /* only change uid if we don't have the correct one */ | |
577 | if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) { | |
578 | if (setreuid(zprivs_state.zuid, zprivs_state.zuid)) { | |
579 | fprintf(stderr, "%s: could not setreuid, %s\n", | |
580 | __func__, safe_strerror(errno)); | |
581 | exit(1); | |
582 | } | |
583 | } | |
584 | ||
585 | /* set the permitted set */ | |
586 | if (setppriv(PRIV_SET, PRIV_PERMITTED, zprivs_state.syscaps_p)) { | |
587 | fprintf(stderr, "%s: error setting permitted set!, %s\n", | |
588 | __func__, safe_strerror(errno)); | |
589 | exit(1); | |
590 | } | |
591 | ||
592 | /* set the inheritable set */ | |
593 | if (setppriv(PRIV_SET, PRIV_INHERITABLE, zprivs_state.syscaps_i)) { | |
594 | fprintf(stderr, "%s: error setting inheritable set!, %s\n", | |
595 | __func__, safe_strerror(errno)); | |
596 | exit(1); | |
597 | } | |
598 | ||
599 | /* we need a minimal basic set for 'effective', potentially for | |
600 | * inheritable too */ | |
601 | minimal = zprivs_caps_minimal(); | |
602 | ||
603 | /* now set the effective set with a subset of basic privileges */ | |
604 | if (setppriv(PRIV_SET, PRIV_EFFECTIVE, minimal)) { | |
605 | fprintf(stderr, "%s: error setting effective set!, %s\n", | |
606 | __func__, safe_strerror(errno)); | |
607 | exit(1); | |
608 | } | |
609 | ||
610 | /* we'll use the minimal set as our working-storage privset */ | |
611 | zprivs_state.caps = minimal; | |
612 | ||
613 | /* set methods for the caller to use */ | |
614 | zprivs->change = zprivs_change_caps; | |
615 | zprivs->current_state = zprivs_state_caps; | |
ceacedba | 616 | } |
617 | ||
d62a17ae | 618 | static void zprivs_caps_terminate(void) |
ceacedba | 619 | { |
d62a17ae | 620 | assert(zprivs_state.caps); |
621 | ||
622 | /* clear all capabilities by using working-storage privset */ | |
623 | setppriv(PRIV_SET, PRIV_EFFECTIVE, zprivs_state.caps); | |
624 | setppriv(PRIV_SET, PRIV_PERMITTED, zprivs_state.caps); | |
625 | setppriv(PRIV_SET, PRIV_INHERITABLE, zprivs_state.caps); | |
626 | ||
627 | /* free up private state */ | |
628 | if (zprivs_state.syscaps_p) | |
629 | priv_freeset(zprivs_state.syscaps_p); | |
630 | if (zprivs_state.syscaps_i) | |
631 | priv_freeset(zprivs_state.syscaps_i); | |
632 | ||
633 | priv_freeset(zprivs_state.caps); | |
ceacedba | 634 | } |
635 | #else /* !HAVE_LCAPS && ! HAVE_SOLARIS_CAPABILITIES */ | |
636 | #error "Neither Solaris nor Linux capabilities, dazed and confused..." | |
637 | #endif /* HAVE_LCAPS */ | |
638 | #endif /* HAVE_CAPABILITIES */ | |
6b0655a2 | 639 | |
d62a17ae | 640 | int zprivs_change_uid(zebra_privs_ops_t op) |
01245821 | 641 | { |
d62a17ae | 642 | if (zprivs_state.zsuid == zprivs_state.zuid) |
643 | return 0; | |
644 | if (op == ZPRIVS_RAISE) | |
645 | return seteuid(zprivs_state.zsuid); | |
646 | else if (op == ZPRIVS_LOWER) | |
647 | return seteuid(zprivs_state.zuid); | |
648 | else | |
649 | return -1; | |
01245821 | 650 | } |
651 | ||
d62a17ae | 652 | zebra_privs_current_t zprivs_state_uid(void) |
01245821 | 653 | { |
d62a17ae | 654 | return ((zprivs_state.zuid == geteuid()) ? ZPRIVS_LOWERED |
655 | : ZPRIVS_RAISED); | |
01245821 | 656 | } |
657 | ||
d62a17ae | 658 | int zprivs_change_null(zebra_privs_ops_t op) |
01245821 | 659 | { |
d62a17ae | 660 | return 0; |
01245821 | 661 | } |
662 | ||
d62a17ae | 663 | zebra_privs_current_t zprivs_state_null(void) |
01245821 | 664 | { |
d62a17ae | 665 | return zprivs_null_state; |
01245821 | 666 | } |
667 | ||
4a9ea50e DL |
668 | #ifndef HAVE_GETGROUPLIST |
669 | /* Solaris 11 has no getgrouplist() */ | |
d62a17ae | 670 | static int getgrouplist(const char *user, gid_t group, gid_t *groups, |
671 | int *ngroups) | |
4a9ea50e | 672 | { |
d62a17ae | 673 | struct group *grp; |
674 | size_t usridx; | |
675 | int pos = 0, ret; | |
676 | ||
677 | if (pos < *ngroups) | |
678 | groups[pos] = group; | |
679 | pos++; | |
680 | ||
681 | setgrent(); | |
682 | while ((grp = getgrent())) { | |
683 | if (grp->gr_gid == group) | |
684 | continue; | |
685 | for (usridx = 0; grp->gr_mem[usridx] != NULL; usridx++) | |
686 | if (!strcmp(grp->gr_mem[usridx], user)) { | |
687 | if (pos < *ngroups) | |
688 | groups[pos] = grp->gr_gid; | |
689 | pos++; | |
690 | break; | |
691 | } | |
692 | } | |
693 | endgrent(); | |
694 | ||
695 | ret = (pos <= *ngroups) ? pos : -1; | |
696 | *ngroups = pos; | |
697 | return ret; | |
4a9ea50e DL |
698 | } |
699 | #endif /* HAVE_GETGROUPLIST */ | |
700 | ||
6017c3a2 DL |
701 | struct zebra_privs_t *_zprivs_raise(struct zebra_privs_t *privs, |
702 | const char *funcname) | |
703 | { | |
704 | int save_errno = errno; | |
705 | ||
706 | if (!privs) | |
707 | return NULL; | |
708 | ||
709 | errno = 0; | |
710 | if (privs->change(ZPRIVS_RAISE)) { | |
711 | zlog_err("%s: Failed to raise privileges (%s)", | |
712 | funcname, safe_strerror(errno)); | |
713 | } | |
714 | errno = save_errno; | |
715 | privs->raised_in_funcname = funcname; | |
716 | return privs; | |
717 | } | |
718 | ||
719 | void _zprivs_lower(struct zebra_privs_t **privs) | |
720 | { | |
721 | int save_errno = errno; | |
722 | ||
723 | if (!*privs) | |
724 | return; | |
725 | ||
726 | errno = 0; | |
727 | if ((*privs)->change(ZPRIVS_LOWER)) { | |
728 | zlog_err("%s: Failed to lower privileges (%s)", | |
729 | (*privs)->raised_in_funcname, safe_strerror(errno)); | |
730 | } | |
731 | errno = save_errno; | |
732 | (*privs)->raised_in_funcname = NULL; | |
733 | *privs = NULL; | |
734 | } | |
735 | ||
37a1f2fb | 736 | void zprivs_preinit(struct zebra_privs_t *zprivs) |
01245821 | 737 | { |
d62a17ae | 738 | struct passwd *pwentry = NULL; |
739 | struct group *grentry = NULL; | |
d62a17ae | 740 | |
741 | if (!zprivs) { | |
742 | fprintf(stderr, "zprivs_init: called with NULL arg!\n"); | |
743 | exit(1); | |
744 | } | |
745 | ||
746 | if (zprivs->vty_group) { | |
747 | /* in a "NULL" setup, this is allowed to fail too, but still | |
748 | * try. */ | |
749 | if ((grentry = getgrnam(zprivs->vty_group))) | |
750 | zprivs_state.vtygrp = grentry->gr_gid; | |
751 | else | |
752 | zprivs_state.vtygrp = (gid_t)-1; | |
753 | } | |
754 | ||
755 | /* NULL privs */ | |
756 | if (!(zprivs->user || zprivs->group || zprivs->cap_num_p | |
757 | || zprivs->cap_num_i)) { | |
758 | zprivs->change = zprivs_change_null; | |
759 | zprivs->current_state = zprivs_state_null; | |
760 | return; | |
761 | } | |
762 | ||
763 | if (zprivs->user) { | |
764 | if ((pwentry = getpwnam(zprivs->user)) == NULL) { | |
765 | /* cant use log.h here as it depends on vty */ | |
766 | fprintf(stderr, | |
767 | "privs_init: could not lookup user %s\n", | |
768 | zprivs->user); | |
769 | exit(1); | |
770 | } | |
771 | ||
772 | zprivs_state.zuid = pwentry->pw_uid; | |
773 | zprivs_state.zgid = pwentry->pw_gid; | |
774 | } | |
775 | ||
776 | grentry = NULL; | |
777 | ||
778 | if (zprivs->group) { | |
779 | if ((grentry = getgrnam(zprivs->group)) == NULL) { | |
780 | fprintf(stderr, | |
781 | "privs_init: could not lookup group %s\n", | |
782 | zprivs->group); | |
783 | exit(1); | |
784 | } | |
785 | ||
786 | zprivs_state.zgid = grentry->gr_gid; | |
787 | } | |
37a1f2fb DL |
788 | } |
789 | ||
790 | void zprivs_init(struct zebra_privs_t *zprivs) | |
791 | { | |
792 | gid_t groups[NGROUPS_MAX]; | |
793 | int i, ngroups = 0; | |
794 | int found = 0; | |
795 | ||
796 | /* NULL privs */ | |
797 | if (!(zprivs->user || zprivs->group || zprivs->cap_num_p | |
798 | || zprivs->cap_num_i)) | |
799 | return; | |
d62a17ae | 800 | |
801 | if (zprivs->user) { | |
802 | ngroups = sizeof(groups); | |
803 | if (getgrouplist(zprivs->user, zprivs_state.zgid, groups, | |
804 | &ngroups) | |
805 | < 0) { | |
806 | /* cant use log.h here as it depends on vty */ | |
807 | fprintf(stderr, | |
808 | "privs_init: could not getgrouplist for user %s\n", | |
809 | zprivs->user); | |
810 | exit(1); | |
811 | } | |
812 | } | |
813 | ||
814 | if (zprivs->vty_group) | |
815 | /* Add the vty_group to the supplementary groups so it can be chowned to | |
9d303b37 | 816 | */ |
d62a17ae | 817 | { |
818 | if (zprivs_state.vtygrp == (gid_t)-1) { | |
819 | fprintf(stderr, | |
820 | "privs_init: could not lookup vty group %s\n", | |
821 | zprivs->vty_group); | |
822 | exit(1); | |
823 | } | |
824 | ||
825 | for (i = 0; i < ngroups; i++) | |
826 | if (groups[i] == zprivs_state.vtygrp) { | |
827 | found++; | |
828 | break; | |
829 | } | |
830 | ||
831 | if (!found) { | |
832 | fprintf(stderr, | |
833 | "privs_init: user(%s) is not part of vty group specified(%s)\n", | |
834 | zprivs->user, zprivs->vty_group); | |
835 | exit(1); | |
836 | } | |
837 | if (i >= ngroups && ngroups < (int)ZEBRA_NUM_OF(groups)) { | |
838 | groups[i] = zprivs_state.vtygrp; | |
839 | } | |
840 | } | |
841 | ||
842 | zprivs_state.zsuid = geteuid(); /* initial uid */ | |
843 | /* add groups only if we changed uid - otherwise skip */ | |
844 | if ((ngroups) && (zprivs_state.zsuid != zprivs_state.zuid)) { | |
845 | if (setgroups(ngroups, groups)) { | |
846 | fprintf(stderr, "privs_init: could not setgroups, %s\n", | |
847 | safe_strerror(errno)); | |
848 | exit(1); | |
849 | } | |
850 | } | |
851 | ||
852 | /* change gid only if we changed uid - otherwise skip */ | |
853 | if ((zprivs_state.zgid) && (zprivs_state.zsuid != zprivs_state.zuid)) { | |
854 | /* change group now, forever. uid we do later */ | |
855 | if (setregid(zprivs_state.zgid, zprivs_state.zgid)) { | |
856 | fprintf(stderr, "zprivs_init: could not setregid, %s\n", | |
857 | safe_strerror(errno)); | |
858 | exit(1); | |
859 | } | |
860 | } | |
861 | ||
ceacedba | 862 | #ifdef HAVE_CAPABILITIES |
d62a17ae | 863 | zprivs_caps_init(zprivs); |
8e04538c DS |
864 | |
865 | /* | |
866 | * If we have initialized the system with no requested | |
867 | * capabilities, change will not have been set | |
868 | * to anything by zprivs_caps_init, As such | |
869 | * we should make sure that when we attempt | |
870 | * to raize privileges that we actually have | |
871 | * a do nothing function to call instead of a | |
872 | * crash :). | |
873 | */ | |
874 | if (!zprivs->change) | |
875 | zprivs->change = zprivs_change_null; | |
876 | ||
d62a17ae | 877 | #else /* !HAVE_CAPABILITIES */ |
878 | /* we dont have caps. we'll need to maintain rid and saved uid | |
879 | * and change euid back to saved uid (who we presume has all neccessary | |
880 | * privileges) whenever we are asked to raise our privileges. | |
881 | * | |
882 | * This is not worth that much security wise, but all we can do. | |
883 | */ | |
884 | zprivs_state.zsuid = geteuid(); | |
885 | /* only change uid if we don't have the correct one */ | |
886 | if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) { | |
887 | if (setreuid(-1, zprivs_state.zuid)) { | |
888 | fprintf(stderr, | |
889 | "privs_init (uid): could not setreuid, %s\n", | |
890 | safe_strerror(errno)); | |
891 | exit(1); | |
892 | } | |
893 | } | |
894 | ||
895 | zprivs->change = zprivs_change_uid; | |
896 | zprivs->current_state = zprivs_state_uid; | |
ceacedba | 897 | #endif /* HAVE_CAPABILITIES */ |
01245821 | 898 | } |
899 | ||
d62a17ae | 900 | void zprivs_terminate(struct zebra_privs_t *zprivs) |
01245821 | 901 | { |
d62a17ae | 902 | if (!zprivs) { |
903 | fprintf(stderr, "%s: no privs struct given, terminating", | |
904 | __func__); | |
905 | exit(0); | |
906 | } | |
907 | ||
ceacedba | 908 | #ifdef HAVE_CAPABILITIES |
4093d47b DL |
909 | if (zprivs->user || zprivs->group || zprivs->cap_num_p |
910 | || zprivs->cap_num_i) | |
911 | zprivs_caps_terminate(); | |
d62a17ae | 912 | #else /* !HAVE_CAPABILITIES */ |
913 | /* only change uid if we don't have the correct one */ | |
914 | if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) { | |
915 | if (setreuid(zprivs_state.zuid, zprivs_state.zuid)) { | |
916 | fprintf(stderr, | |
917 | "privs_terminate: could not setreuid, %s", | |
918 | safe_strerror(errno)); | |
919 | exit(1); | |
920 | } | |
921 | } | |
01245821 | 922 | #endif /* HAVE_LCAPS */ |
ceacedba | 923 | |
d62a17ae | 924 | zprivs->change = zprivs_change_null; |
925 | zprivs->current_state = zprivs_state_null; | |
926 | zprivs_null_state = ZPRIVS_LOWERED; | |
927 | return; | |
01245821 | 928 | } |
ba3a0bc5 | 929 | |
d62a17ae | 930 | void zprivs_get_ids(struct zprivs_ids_t *ids) |
ba3a0bc5 | 931 | { |
932 | ||
d62a17ae | 933 | ids->uid_priv = getuid(); |
934 | (zprivs_state.zuid) ? (ids->uid_normal = zprivs_state.zuid) | |
935 | : (ids->uid_normal = -1); | |
936 | (zprivs_state.zgid) ? (ids->gid_normal = zprivs_state.zgid) | |
937 | : (ids->gid_normal = -1); | |
938 | (zprivs_state.vtygrp) ? (ids->gid_vty = zprivs_state.vtygrp) | |
939 | : (ids->gid_vty = -1); | |
940 | ||
941 | return; | |
ba3a0bc5 | 942 | } |