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01245821 | 1 | /* |
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 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with GNU Zebra; see the file COPYING. If not, write to the Free | |
21 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
22 | * 02111-1307, USA. | |
23 | */ | |
01245821 | 24 | #include <zebra.h> |
25 | #include "log.h" | |
26 | #include "privs.h" | |
27 | #include "memory.h" | |
01245821 | 28 | |
ceacedba | 29 | #ifdef HAVE_CAPABILITIES |
30 | /* sort out some generic internal types for: | |
31 | * | |
32 | * privilege values (cap_value_t, priv_t) -> pvalue_t | |
33 | * privilege set (..., priv_set_t) -> pset_t | |
34 | * privilege working storage (cap_t, ...) -> pstorage_t | |
35 | * | |
36 | * values we think of as numeric (they're ints really, but we dont know) | |
37 | * sets are mostly opaque, to hold a set of privileges, related in some way. | |
38 | * storage binds together a set of sets we're interested in. | |
39 | * (in reality: cap_value_t and priv_t are ints) | |
40 | */ | |
41 | #ifdef HAVE_LCAPS | |
42 | /* Linux doesn't have a 'set' type: a set of related privileges */ | |
43 | struct _pset { | |
44 | int num; | |
45 | cap_value_t *caps; | |
46 | }; | |
47 | typedef cap_value_t pvalue_t; | |
48 | typedef struct _pset pset_t; | |
49 | typedef cap_t pstorage_t; | |
6b0655a2 | 50 | |
ceacedba | 51 | #elif defined (HAVE_SOLARIS_CAPABILITIES) |
52 | typedef priv_t pvalue_t; | |
53 | typedef priv_set_t pset_t; | |
54 | typedef priv_set_t *pstorage_t; | |
55 | #else /* neither LCAPS nor SOLARIS_CAPABILITIES */ | |
56 | #error "HAVE_CAPABILITIES defined, but neither LCAPS nor Solaris Capabilties!" | |
57 | #endif /* HAVE_LCAPS */ | |
58 | #endif /* HAVE_CAPABILITIES */ | |
6b0655a2 | 59 | |
ceacedba | 60 | /* the default NULL state we report is RAISED, but could be LOWERED if |
61 | * zprivs_terminate is called and the NULL handler is installed. | |
62 | */ | |
63 | static zebra_privs_current_t zprivs_null_state = ZPRIVS_RAISED; | |
64 | ||
01245821 | 65 | /* internal privileges state */ |
66 | static struct _zprivs_t | |
67 | { | |
ceacedba | 68 | #ifdef HAVE_CAPABILITIES |
69 | pstorage_t caps; /* working storage */ | |
70 | pset_t *syscaps_p; /* system-type requested permitted caps */ | |
71 | pset_t *syscaps_i; /* system-type requested inheritable caps */ | |
72 | #endif /* HAVE_CAPABILITIES */ | |
01245821 | 73 | uid_t zuid, /* uid to run as */ |
74 | zsuid; /* saved uid */ | |
75 | gid_t zgid; /* gid to run as */ | |
ba3a0bc5 | 76 | gid_t vtygrp; /* gid for vty sockets */ |
01245821 | 77 | } zprivs_state; |
78 | ||
79 | /* externally exported but not directly accessed functions */ | |
ceacedba | 80 | #ifdef HAVE_CAPABILITIES |
01245821 | 81 | int zprivs_change_caps (zebra_privs_ops_t); |
82 | zebra_privs_current_t zprivs_state_caps (void); | |
ceacedba | 83 | #endif /* HAVE_CAPABILITIES */ |
01245821 | 84 | int zprivs_change_uid (zebra_privs_ops_t); |
85 | zebra_privs_current_t zprivs_state_uid (void); | |
86 | int zprivs_change_null (zebra_privs_ops_t); | |
87 | zebra_privs_current_t zprivs_state_null (void); | |
01245821 | 88 | |
ceacedba | 89 | #ifdef HAVE_CAPABILITIES |
90 | /* internal capability API */ | |
91 | static pset_t *zcaps2sys (zebra_capabilities_t *, int); | |
92 | static void zprivs_caps_init (struct zebra_privs_t *); | |
93 | static void zprivs_caps_terminate (void); | |
94 | ||
95 | /* Map of Quagga abstract capabilities to system capabilities */ | |
96 | static struct | |
97 | { | |
98 | int num; | |
99 | pvalue_t *system_caps; | |
100 | } cap_map [ZCAP_MAX] = | |
01245821 | 101 | { |
ceacedba | 102 | #ifdef HAVE_LCAPS /* Quagga -> Linux capabilities mappings */ |
103 | [ZCAP_SETID] = { 2, (pvalue_t []) { CAP_SETGID, | |
104 | CAP_SETUID }, }, | |
1b322039 | 105 | [ZCAP_BIND] = { 2, (pvalue_t []) { CAP_NET_BIND_SERVICE }, }, |
ceacedba | 106 | [ZCAP_NET_ADMIN] = { 1, (pvalue_t []) { CAP_NET_ADMIN }, }, |
107 | [ZCAP_NET_RAW] = { 1, (pvalue_t []) { CAP_NET_RAW }, }, | |
108 | [ZCAP_CHROOT] = { 1, (pvalue_t []) { CAP_SYS_CHROOT, }, }, | |
109 | [ZCAP_NICE] = { 1, (pvalue_t []) { CAP_SYS_NICE }, }, | |
110 | [ZCAP_PTRACE] = { 1, (pvalue_t []) { CAP_SYS_PTRACE }, }, | |
111 | [ZCAP_DAC_OVERRIDE] = { 1, (pvalue_t []) { CAP_DAC_OVERRIDE }, }, | |
112 | [ZCAP_READ_SEARCH] = { 1, (pvalue_t []) { CAP_DAC_READ_SEARCH }, }, | |
113 | [ZCAP_SYS_ADMIN] = { 1, (pvalue_t []) { CAP_SYS_ADMIN }, }, | |
114 | [ZCAP_FOWNER] = { 1, (pvalue_t []) { CAP_FOWNER }, }, | |
115 | #elif defined(HAVE_SOLARIS_CAPABILITIES) /* HAVE_LCAPS */ | |
116 | /* Quagga -> Solaris privilege mappings */ | |
117 | [ZCAP_SETID] = { 1, (pvalue_t []) { PRIV_PROC_SETID }, }, | |
118 | [ZCAP_BIND] = { 1, (pvalue_t []) { PRIV_NET_PRIVADDR }, }, | |
6b148faa PJ |
119 | /* IP_CONFIG is a subset of NET_CONFIG and is allowed in zones */ |
120 | #ifdef PRIV_SYS_IP_CONFIG | |
121 | [ZCAP_NET_ADMIN] = { 1, (pvalue_t []) { PRIV_SYS_IP_CONFIG }, }, | |
122 | #else | |
ceacedba | 123 | [ZCAP_NET_ADMIN] = { 1, (pvalue_t []) { PRIV_SYS_NET_CONFIG }, }, |
6b148faa | 124 | #endif |
ceacedba | 125 | [ZCAP_NET_RAW] = { 2, (pvalue_t []) { PRIV_NET_RAWACCESS, |
126 | PRIV_NET_ICMPACCESS }, }, | |
127 | [ZCAP_CHROOT] = { 1, (pvalue_t []) { PRIV_PROC_CHROOT }, }, | |
128 | [ZCAP_NICE] = { 1, (pvalue_t []) { PRIV_PROC_PRIOCNTL }, }, | |
129 | [ZCAP_PTRACE] = { 1, (pvalue_t []) { PRIV_PROC_SESSION }, }, | |
130 | [ZCAP_DAC_OVERRIDE] = { 2, (pvalue_t []) { PRIV_FILE_DAC_EXECUTE, | |
131 | PRIV_FILE_DAC_READ, | |
132 | PRIV_FILE_DAC_SEARCH, | |
133 | PRIV_FILE_DAC_WRITE, | |
134 | PRIV_FILE_DAC_SEARCH }, }, | |
135 | [ZCAP_READ_SEARCH] = { 2, (pvalue_t []) { PRIV_FILE_DAC_SEARCH, | |
136 | PRIV_FILE_DAC_READ }, }, | |
137 | [ZCAP_SYS_ADMIN] = { 1, (pvalue_t []) { PRIV_SYS_ADMIN }, }, | |
138 | [ZCAP_FOWNER] = { 1, (pvalue_t []) { PRIV_FILE_OWNER }, }, | |
139 | #endif /* HAVE_SOLARIS_CAPABILITIES */ | |
01245821 | 140 | }; |
6b0655a2 | 141 | |
ceacedba | 142 | #ifdef HAVE_LCAPS |
143 | /* Linux forms of capabilities methods */ | |
01245821 | 144 | /* convert zebras privileges to system capabilities */ |
ceacedba | 145 | static pset_t * |
01245821 | 146 | zcaps2sys (zebra_capabilities_t *zcaps, int num) |
147 | { | |
ceacedba | 148 | pset_t *syscaps; |
149 | int i, j = 0, count = 0; | |
01245821 | 150 | |
151 | if (!num) | |
152 | return NULL; | |
ceacedba | 153 | |
154 | /* first count up how many system caps we have */ | |
155 | for (i= 0; i < num; i++) | |
156 | count += cap_map[zcaps[i]].num; | |
157 | ||
158 | if ( (syscaps = XCALLOC (MTYPE_PRIVS, (sizeof(pset_t) * num))) == NULL) | |
01245821 | 159 | { |
ceacedba | 160 | fprintf (stderr, "%s: could not allocate syscaps!", __func__); |
01245821 | 161 | return NULL; |
162 | } | |
163 | ||
ceacedba | 164 | syscaps->caps = XCALLOC (MTYPE_PRIVS, (sizeof (pvalue_t) * count)); |
165 | ||
166 | if (!syscaps->caps) | |
01245821 | 167 | { |
ceacedba | 168 | fprintf (stderr, "%s: could not XCALLOC caps!", __func__); |
169 | return NULL; | |
01245821 | 170 | } |
ceacedba | 171 | |
172 | /* copy the capabilities over */ | |
173 | count = 0; | |
174 | for (i=0; i < num; i++) | |
175 | for (j = 0; j < cap_map[zcaps[i]].num; j++) | |
176 | syscaps->caps[count++] = cap_map[zcaps[i]].system_caps[j]; | |
177 | ||
178 | /* iterations above should be exact same as previous count, obviously.. */ | |
179 | syscaps->num = count; | |
180 | ||
01245821 | 181 | return syscaps; |
182 | } | |
183 | ||
184 | /* set or clear the effective capabilities to/from permitted */ | |
185 | int | |
186 | zprivs_change_caps (zebra_privs_ops_t op) | |
187 | { | |
188 | cap_flag_value_t cflag; | |
189 | ||
ceacedba | 190 | /* should be no possibility of being called without valid caps */ |
191 | assert (zprivs_state.syscaps_p && zprivs_state.caps); | |
192 | if (! (zprivs_state.syscaps_p && zprivs_state.caps)) | |
193 | exit (1); | |
194 | ||
01245821 | 195 | if (op == ZPRIVS_RAISE) |
196 | cflag = CAP_SET; | |
197 | else if (op == ZPRIVS_LOWER) | |
198 | cflag = CAP_CLEAR; | |
199 | else | |
200 | return -1; | |
201 | ||
202 | if ( !cap_set_flag (zprivs_state.caps, CAP_EFFECTIVE, | |
ceacedba | 203 | zprivs_state.syscaps_p->num, |
204 | zprivs_state.syscaps_p->caps, | |
205 | cflag)) | |
01245821 | 206 | return cap_set_proc (zprivs_state.caps); |
207 | return -1; | |
208 | } | |
209 | ||
210 | zebra_privs_current_t | |
211 | zprivs_state_caps (void) | |
212 | { | |
213 | int i; | |
01245821 | 214 | cap_flag_value_t val; |
ceacedba | 215 | |
216 | /* should be no possibility of being called without valid caps */ | |
217 | assert (zprivs_state.syscaps_p && zprivs_state.caps); | |
218 | if (! (zprivs_state.syscaps_p && zprivs_state.caps)) | |
219 | exit (1); | |
01245821 | 220 | |
ceacedba | 221 | for (i=0; i < zprivs_state.syscaps_p->num; i++) |
01245821 | 222 | { |
ceacedba | 223 | if ( cap_get_flag (zprivs_state.caps, zprivs_state.syscaps_p->caps[i], |
01245821 | 224 | CAP_EFFECTIVE, &val) ) |
ceacedba | 225 | { |
226 | zlog_warn ("zprivs_state_caps: could not cap_get_flag, %s", | |
227 | safe_strerror (errno) ); | |
228 | return ZPRIVS_UNKNOWN; | |
229 | } | |
01245821 | 230 | if (val == CAP_SET) |
33b72948 | 231 | return ZPRIVS_RAISED; |
01245821 | 232 | } |
233 | return ZPRIVS_LOWERED; | |
234 | } | |
235 | ||
ceacedba | 236 | static void |
237 | zprivs_caps_init (struct zebra_privs_t *zprivs) | |
238 | { | |
239 | zprivs_state.syscaps_p = zcaps2sys (zprivs->caps_p, zprivs->cap_num_p); | |
240 | zprivs_state.syscaps_i = zcaps2sys (zprivs->caps_i, zprivs->cap_num_i); | |
241 | ||
242 | /* Tell kernel we want caps maintained across uid changes */ | |
243 | if ( prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1 ) | |
244 | { | |
245 | fprintf (stderr, "privs_init: could not set PR_SET_KEEPCAPS, %s\n", | |
246 | safe_strerror (errno) ); | |
247 | exit(1); | |
248 | } | |
249 | ||
250 | if ( !zprivs_state.syscaps_p ) | |
251 | { | |
252 | fprintf (stderr, "privs_init: capabilities enabled, " | |
253 | "but no capabilities supplied\n"); | |
254 | } | |
255 | ||
ceacedba | 256 | /* we have caps, we have no need to ever change back the original user */ |
257 | if (zprivs_state.zuid) | |
258 | { | |
259 | if ( setreuid (zprivs_state.zuid, zprivs_state.zuid) ) | |
260 | { | |
261 | fprintf (stderr, "zprivs_init (cap): could not setreuid, %s\n", | |
262 | safe_strerror (errno)); | |
263 | exit (1); | |
264 | } | |
265 | } | |
266 | ||
924f9d32 PJ |
267 | if ( !(zprivs_state.caps = cap_init()) ) |
268 | { | |
269 | fprintf (stderr, "privs_init: failed to cap_init, %s\n", | |
270 | safe_strerror (errno)); | |
271 | exit (1); | |
272 | } | |
273 | ||
ceacedba | 274 | if ( cap_clear (zprivs_state.caps) ) |
275 | { | |
276 | fprintf (stderr, "privs_init: failed to cap_clear, %s\n", | |
277 | safe_strerror (errno)); | |
278 | exit (1); | |
279 | } | |
280 | ||
281 | /* set permitted caps */ | |
282 | cap_set_flag(zprivs_state.caps, CAP_PERMITTED, | |
283 | zprivs_state.syscaps_p->num, | |
284 | zprivs_state.syscaps_p->caps, | |
285 | CAP_SET); | |
286 | ||
287 | /* set inheritable caps, if any */ | |
288 | if (zprivs_state.syscaps_i && zprivs_state.syscaps_i->num) | |
289 | { | |
290 | cap_set_flag(zprivs_state.caps, CAP_INHERITABLE, | |
291 | zprivs_state.syscaps_i->num, | |
292 | zprivs_state.syscaps_i->caps, | |
293 | CAP_SET); | |
294 | } | |
295 | ||
296 | /* apply caps. CAP_EFFECTIVE is cleared. we'll raise the caps as | |
297 | * and when, and only when, they are needed. | |
298 | */ | |
299 | if ( cap_set_proc (zprivs_state.caps) ) | |
300 | { | |
0b16a517 CF |
301 | cap_t current_caps; |
302 | char *current_caps_text = NULL; | |
303 | char *wanted_caps_text = NULL; | |
304 | ||
305 | fprintf(stderr, "privs_init: initial cap_set_proc failed: %s\n", | |
306 | safe_strerror(errno)); | |
307 | ||
308 | current_caps = cap_get_proc(); | |
309 | if (current_caps) | |
310 | current_caps_text = cap_to_text(current_caps, NULL); | |
311 | ||
312 | wanted_caps_text = cap_to_text(zprivs_state.caps, NULL); | |
313 | fprintf(stderr, "Wanted caps: %s\n", wanted_caps_text ? wanted_caps_text : "???"); | |
314 | fprintf(stderr, "Have caps: %s\n", current_caps_text ? current_caps_text : "???"); | |
315 | ||
ceacedba | 316 | exit (1); |
317 | } | |
318 | ||
319 | /* set methods for the caller to use */ | |
320 | zprivs->change = zprivs_change_caps; | |
321 | zprivs->current_state = zprivs_state_caps; | |
322 | } | |
323 | ||
324 | static void | |
325 | zprivs_caps_terminate (void) | |
326 | { | |
327 | /* clear all capabilities */ | |
328 | if (zprivs_state.caps) | |
329 | cap_clear (zprivs_state.caps); | |
01245821 | 330 | |
ceacedba | 331 | /* and boom, capabilities are gone forever */ |
332 | if ( cap_set_proc (zprivs_state.caps) ) | |
333 | { | |
334 | fprintf (stderr, "privs_terminate: cap_set_proc failed, %s", | |
335 | safe_strerror (errno) ); | |
336 | exit (1); | |
337 | } | |
338 | ||
339 | /* free up private state */ | |
340 | if (zprivs_state.syscaps_p->num) | |
341 | { | |
342 | XFREE (MTYPE_PRIVS, zprivs_state.syscaps_p->caps); | |
343 | XFREE (MTYPE_PRIVS, zprivs_state.syscaps_p); | |
344 | } | |
345 | ||
346 | if (zprivs_state.syscaps_i && zprivs_state.syscaps_i->num) | |
347 | { | |
348 | XFREE (MTYPE_PRIVS, zprivs_state.syscaps_i->caps); | |
349 | XFREE (MTYPE_PRIVS, zprivs_state.syscaps_i); | |
350 | } | |
351 | ||
352 | cap_free (zprivs_state.caps); | |
353 | } | |
354 | #elif defined (HAVE_SOLARIS_CAPABILITIES) /* !HAVE_LCAPS */ | |
6b0655a2 | 355 | |
ceacedba | 356 | /* Solaris specific capability/privilege methods |
357 | * | |
358 | * Resources: | |
359 | * - the 'privileges' man page | |
360 | * - http://cvs.opensolaris.org | |
361 | * - http://blogs.sun.com/roller/page/gbrunett?entry=privilege_enabling_set_id_programs1 | |
362 | */ | |
363 | ||
01070b9e BB |
364 | static pset_t * |
365 | zprivs_caps_minimal () | |
366 | { | |
367 | pset_t *minimal; | |
368 | ||
369 | if ((minimal = priv_str_to_set("basic", ",", NULL)) == NULL) | |
370 | { | |
371 | fprintf (stderr, "%s: couldn't get basic set!\n", __func__); | |
372 | exit (1); | |
373 | } | |
374 | ||
375 | /* create a minimal privilege set from the basic set */ | |
376 | (void) priv_delset(minimal, PRIV_PROC_EXEC); | |
377 | (void) priv_delset(minimal, PRIV_PROC_INFO); | |
378 | (void) priv_delset(minimal, PRIV_PROC_SESSION); | |
379 | (void) priv_delset(minimal, PRIV_FILE_LINK_ANY); | |
380 | ||
381 | return minimal; | |
382 | } | |
383 | ||
ceacedba | 384 | /* convert zebras privileges to system capabilities */ |
385 | static pset_t * | |
386 | zcaps2sys (zebra_capabilities_t *zcaps, int num) | |
387 | { | |
388 | pset_t *syscaps; | |
6e0f1b94 | 389 | int i, j = 0; |
ceacedba | 390 | |
391 | if ((syscaps = priv_allocset()) == NULL) | |
392 | { | |
393 | fprintf (stderr, "%s: could not allocate syscaps!\n", __func__); | |
394 | exit (1); | |
395 | } | |
396 | ||
397 | priv_emptyset (syscaps); | |
398 | ||
399 | for (i=0; i < num; i++) | |
400 | for (j = 0; j < cap_map[zcaps[i]].num; j++) | |
401 | priv_addset (syscaps, cap_map[zcaps[i]].system_caps[j]); | |
402 | ||
403 | return syscaps; | |
404 | } | |
405 | ||
406 | /* callback exported to users to RAISE and LOWER effective privileges | |
407 | * from nothing to the given permitted set and back down | |
408 | */ | |
409 | int | |
410 | zprivs_change_caps (zebra_privs_ops_t op) | |
411 | { | |
01070b9e | 412 | pset_t *privset; |
ceacedba | 413 | |
414 | /* should be no possibility of being called without valid caps */ | |
415 | assert (zprivs_state.syscaps_p); | |
416 | if (!zprivs_state.syscaps_p) | |
01070b9e BB |
417 | { |
418 | fprintf (stderr, "%s: Eek, missing privileged caps!", __func__); | |
419 | exit (1); | |
420 | } | |
421 | ||
422 | assert (zprivs_state.caps); | |
423 | if (!zprivs_state.caps) | |
ceacedba | 424 | { |
425 | fprintf (stderr, "%s: Eek, missing caps!", __func__); | |
426 | exit (1); | |
427 | } | |
01070b9e BB |
428 | |
429 | /* to raise: copy original permitted as our working effective set | |
430 | * to lower: copy regular effective set stored in zprivs_state.caps | |
ceacedba | 431 | */ |
432 | if (op == ZPRIVS_RAISE) | |
01070b9e | 433 | privset = zprivs_state.syscaps_p; |
ceacedba | 434 | else if (op == ZPRIVS_LOWER) |
01070b9e | 435 | privset = zprivs_state.caps; |
ceacedba | 436 | else |
437 | return -1; | |
438 | ||
01070b9e | 439 | if (setppriv (PRIV_SET, PRIV_EFFECTIVE, privset) != 0) |
ceacedba | 440 | return -1; |
441 | ||
442 | return 0; | |
443 | } | |
444 | ||
445 | /* Retrieve current privilege state, is it RAISED or LOWERED? */ | |
446 | zebra_privs_current_t | |
447 | zprivs_state_caps (void) | |
448 | { | |
449 | zebra_privs_current_t result; | |
450 | pset_t *effective; | |
451 | ||
452 | if ( (effective = priv_allocset()) == NULL) | |
453 | { | |
6e0f1b94 | 454 | fprintf (stderr, "%s: failed to get priv_allocset! %s\n", __func__, |
ceacedba | 455 | safe_strerror (errno)); |
456 | return ZPRIVS_UNKNOWN; | |
457 | } | |
458 | ||
459 | if (getppriv (PRIV_EFFECTIVE, effective)) | |
460 | { | |
6e0f1b94 | 461 | fprintf (stderr, "%s: failed to get state! %s\n", __func__, |
ceacedba | 462 | safe_strerror (errno)); |
463 | result = ZPRIVS_UNKNOWN; | |
464 | } | |
465 | else | |
466 | { | |
01070b9e BB |
467 | if (priv_isequalset (effective, zprivs_state.syscaps_p)) |
468 | result = ZPRIVS_RAISED; | |
469 | else if (priv_isequalset (effective, zprivs_state.caps)) | |
ceacedba | 470 | result = ZPRIVS_LOWERED; |
471 | else | |
01070b9e | 472 | result = ZPRIVS_UNKNOWN; |
ceacedba | 473 | } |
474 | ||
01070b9e | 475 | priv_freeset (effective); |
ceacedba | 476 | return result; |
477 | } | |
478 | ||
479 | static void | |
480 | zprivs_caps_init (struct zebra_privs_t *zprivs) | |
481 | { | |
482 | pset_t *basic; | |
01070b9e | 483 | pset_t *minimal; |
ceacedba | 484 | |
485 | /* the specified sets */ | |
486 | zprivs_state.syscaps_p = zcaps2sys (zprivs->caps_p, zprivs->cap_num_p); | |
487 | zprivs_state.syscaps_i = zcaps2sys (zprivs->caps_i, zprivs->cap_num_i); | |
488 | ||
489 | /* nonsensical to have gotten here but not have capabilities */ | |
490 | if (!zprivs_state.syscaps_p) | |
491 | { | |
492 | fprintf (stderr, "%s: capabilities enabled, " | |
493 | "but no valid capabilities supplied\n", | |
494 | __func__); | |
495 | } | |
496 | ||
497 | /* We retain the basic set in our permitted set, as Linux has no | |
498 | * equivalent. The basic set on Linux hence is implicit, always | |
499 | * there. | |
500 | */ | |
501 | if ((basic = priv_str_to_set("basic", ",", NULL)) == NULL) | |
502 | { | |
503 | fprintf (stderr, "%s: couldn't get basic set!\n", __func__); | |
504 | exit (1); | |
505 | } | |
506 | ||
507 | /* Add the basic set to the permitted set */ | |
508 | priv_union (basic, zprivs_state.syscaps_p); | |
509 | priv_freeset (basic); | |
510 | ||
ceacedba | 511 | /* Hey kernel, we know about privileges! |
512 | * this isn't strictly required, use of setppriv should have same effect | |
513 | */ | |
514 | if (setpflags (PRIV_AWARE, 1)) | |
515 | { | |
516 | fprintf (stderr, "%s: error setting PRIV_AWARE!, %s\n", __func__, | |
517 | safe_strerror (errno) ); | |
518 | exit (1); | |
519 | } | |
520 | ||
521 | /* need either valid or empty sets for both p and i.. */ | |
522 | assert (zprivs_state.syscaps_i && zprivs_state.syscaps_p); | |
523 | ||
924f9d32 PJ |
524 | /* we have caps, we have no need to ever change back the original user |
525 | * change real, effective and saved to the specified user. | |
526 | */ | |
527 | if (zprivs_state.zuid) | |
528 | { | |
529 | if ( setreuid (zprivs_state.zuid, zprivs_state.zuid) ) | |
530 | { | |
531 | fprintf (stderr, "%s: could not setreuid, %s\n", | |
532 | __func__, safe_strerror (errno)); | |
533 | exit (1); | |
534 | } | |
535 | } | |
536 | ||
ceacedba | 537 | /* set the permitted set */ |
538 | if (setppriv (PRIV_SET, PRIV_PERMITTED, zprivs_state.syscaps_p)) | |
539 | { | |
540 | fprintf (stderr, "%s: error setting permitted set!, %s\n", __func__, | |
541 | safe_strerror (errno) ); | |
542 | exit (1); | |
543 | } | |
544 | ||
545 | /* set the inheritable set */ | |
546 | if (setppriv (PRIV_SET, PRIV_INHERITABLE, zprivs_state.syscaps_i)) | |
547 | { | |
548 | fprintf (stderr, "%s: error setting inheritable set!, %s\n", __func__, | |
549 | safe_strerror (errno) ); | |
550 | exit (1); | |
551 | } | |
552 | ||
01070b9e BB |
553 | /* we need a minimal basic set for 'effective', potentially for inheritable too */ |
554 | minimal = zprivs_caps_minimal(); | |
555 | ||
556 | /* now set the effective set with a subset of basic privileges */ | |
557 | if (setppriv (PRIV_SET, PRIV_EFFECTIVE, minimal)) | |
ceacedba | 558 | { |
559 | fprintf (stderr, "%s: error setting effective set!, %s\n", __func__, | |
560 | safe_strerror (errno) ); | |
561 | exit (1); | |
562 | } | |
563 | ||
01070b9e BB |
564 | /* we'll use the minimal set as our working-storage privset */ |
565 | zprivs_state.caps = minimal; | |
ceacedba | 566 | |
567 | /* set methods for the caller to use */ | |
568 | zprivs->change = zprivs_change_caps; | |
569 | zprivs->current_state = zprivs_state_caps; | |
570 | } | |
571 | ||
572 | static void | |
573 | zprivs_caps_terminate (void) | |
574 | { | |
575 | assert (zprivs_state.caps); | |
576 | ||
01070b9e | 577 | /* clear all capabilities by using working-storage privset */ |
ceacedba | 578 | setppriv (PRIV_SET, PRIV_EFFECTIVE, zprivs_state.caps); |
579 | setppriv (PRIV_SET, PRIV_PERMITTED, zprivs_state.caps); | |
580 | setppriv (PRIV_SET, PRIV_INHERITABLE, zprivs_state.caps); | |
581 | ||
582 | /* free up private state */ | |
583 | if (zprivs_state.syscaps_p) | |
584 | priv_freeset (zprivs_state.syscaps_p); | |
585 | if (zprivs_state.syscaps_i) | |
586 | priv_freeset (zprivs_state.syscaps_i); | |
587 | ||
588 | priv_freeset (zprivs_state.caps); | |
589 | } | |
590 | #else /* !HAVE_LCAPS && ! HAVE_SOLARIS_CAPABILITIES */ | |
591 | #error "Neither Solaris nor Linux capabilities, dazed and confused..." | |
592 | #endif /* HAVE_LCAPS */ | |
593 | #endif /* HAVE_CAPABILITIES */ | |
6b0655a2 | 594 | |
01245821 | 595 | int |
596 | zprivs_change_uid (zebra_privs_ops_t op) | |
597 | { | |
28efaa36 | 598 | |
01245821 | 599 | if (op == ZPRIVS_RAISE) |
600 | return seteuid (zprivs_state.zsuid); | |
601 | else if (op == ZPRIVS_LOWER) | |
602 | return seteuid (zprivs_state.zuid); | |
603 | else | |
604 | return -1; | |
605 | } | |
606 | ||
607 | zebra_privs_current_t | |
608 | zprivs_state_uid (void) | |
609 | { | |
610 | return ( (zprivs_state.zuid == geteuid()) ? ZPRIVS_LOWERED : ZPRIVS_RAISED); | |
611 | } | |
612 | ||
613 | int | |
614 | zprivs_change_null (zebra_privs_ops_t op) | |
615 | { | |
616 | return 0; | |
617 | } | |
618 | ||
619 | zebra_privs_current_t | |
620 | zprivs_state_null (void) | |
621 | { | |
ceacedba | 622 | return zprivs_null_state; |
01245821 | 623 | } |
624 | ||
01245821 | 625 | void |
626 | zprivs_init(struct zebra_privs_t *zprivs) | |
627 | { | |
628 | struct passwd *pwentry = NULL; | |
629 | struct group *grentry = NULL; | |
6d757816 TT |
630 | gid_t groups[NGROUPS_MAX]; |
631 | int i, ngroups = 0; | |
01245821 | 632 | |
ba3a0bc5 | 633 | if (!zprivs) |
634 | { | |
58a9d81c | 635 | fprintf (stderr, "zprivs_init: called with NULL arg!\n"); |
ba3a0bc5 | 636 | exit (1); |
637 | } | |
638 | ||
01245821 | 639 | /* NULL privs */ |
640 | if (! (zprivs->user || zprivs->group | |
641 | || zprivs->cap_num_p || zprivs->cap_num_i) ) | |
642 | { | |
643 | zprivs->change = zprivs_change_null; | |
644 | zprivs->current_state = zprivs_state_null; | |
645 | return; | |
646 | } | |
647 | ||
648 | if (zprivs->user) | |
649 | { | |
6d757816 | 650 | if ( (pwentry = getpwnam (zprivs->user)) == NULL ) |
ba3a0bc5 | 651 | { |
58a9d81c | 652 | /* cant use log.h here as it depends on vty */ |
653 | fprintf (stderr, "privs_init: could not lookup user %s\n", | |
654 | zprivs->user); | |
ba3a0bc5 | 655 | exit (1); |
656 | } | |
6d757816 TT |
657 | |
658 | zprivs_state.zuid = pwentry->pw_uid; | |
659 | zprivs_state.zgid = pwentry->pw_gid; | |
ba3a0bc5 | 660 | } |
661 | ||
662 | grentry = NULL; | |
663 | ||
6d757816 TT |
664 | if (zprivs->group) |
665 | { | |
666 | if ( (grentry = getgrnam (zprivs->group)) == NULL ) | |
667 | { | |
668 | fprintf (stderr, "privs_init: could not lookup group %s\n", | |
669 | zprivs->group); | |
670 | exit (1); | |
671 | } | |
672 | ||
673 | zprivs_state.zgid = grentry->gr_gid; | |
674 | } | |
675 | ||
676 | if (zprivs->user) | |
677 | { | |
678 | ngroups = sizeof(groups); | |
679 | if ( (ngroups = getgrouplist (zprivs->user, zprivs_state.zgid, groups, &ngroups )) < 0 ) | |
680 | { | |
681 | /* cant use log.h here as it depends on vty */ | |
682 | fprintf (stderr, "privs_init: could not getgrouplist for user %s\n", | |
683 | zprivs->user); | |
684 | exit (1); | |
685 | } | |
686 | } | |
687 | ||
ba3a0bc5 | 688 | if (zprivs->vty_group) |
689 | /* Add the vty_group to the supplementary groups so it can be chowned to */ | |
690 | { | |
691 | if ( (grentry = getgrnam (zprivs->vty_group)) ) | |
692 | { | |
693 | zprivs_state.vtygrp = grentry->gr_gid; | |
6d757816 TT |
694 | |
695 | for ( i = 0; i < ngroups; i++ ) | |
696 | if ( groups[i] == zprivs_state.vtygrp ) | |
697 | break; | |
698 | ||
699 | if ( i >= ngroups && ngroups < (int) ZEBRA_NUM_OF(groups) ) | |
ba3a0bc5 | 700 | { |
6d757816 TT |
701 | groups[i] = zprivs_state.vtygrp; |
702 | } | |
ba3a0bc5 | 703 | } |
01245821 | 704 | else |
705 | { | |
58a9d81c | 706 | fprintf (stderr, "privs_init: could not lookup vty group %s\n", |
707 | zprivs->vty_group); | |
01245821 | 708 | exit (1); |
709 | } | |
710 | } | |
6d757816 TT |
711 | |
712 | if (ngroups) | |
01245821 | 713 | { |
6d757816 | 714 | if ( setgroups (ngroups, groups) ) |
ba3a0bc5 | 715 | { |
6d757816 TT |
716 | fprintf (stderr, "privs_init: could not setgroups, %s\n", |
717 | safe_strerror (errno) ); | |
01245821 | 718 | exit (1); |
719 | } | |
6d757816 TT |
720 | } |
721 | ||
722 | if (zprivs_state.zgid) | |
723 | { | |
01245821 | 724 | /* change group now, forever. uid we do later */ |
725 | if ( setregid (zprivs_state.zgid, zprivs_state.zgid) ) | |
726 | { | |
58a9d81c | 727 | fprintf (stderr, "zprivs_init: could not setregid, %s\n", |
6099b3b5 | 728 | safe_strerror (errno) ); |
01245821 | 729 | exit (1); |
730 | } | |
731 | } | |
732 | ||
ceacedba | 733 | #ifdef HAVE_CAPABILITIES |
734 | zprivs_caps_init (zprivs); | |
735 | #else /* !HAVE_CAPABILITIES */ | |
01245821 | 736 | /* we dont have caps. we'll need to maintain rid and saved uid |
737 | * and change euid back to saved uid (who we presume has all neccessary | |
738 | * privileges) whenever we are asked to raise our privileges. | |
ceacedba | 739 | * |
740 | * This is not worth that much security wise, but all we can do. | |
01245821 | 741 | */ |
742 | zprivs_state.zsuid = geteuid(); | |
743 | if ( zprivs_state.zuid ) | |
744 | { | |
745 | if ( setreuid (-1, zprivs_state.zuid) ) | |
746 | { | |
58a9d81c | 747 | fprintf (stderr, "privs_init (uid): could not setreuid, %s\n", |
6099b3b5 | 748 | safe_strerror (errno)); |
01245821 | 749 | exit (1); |
750 | } | |
751 | } | |
752 | ||
753 | zprivs->change = zprivs_change_uid; | |
754 | zprivs->current_state = zprivs_state_uid; | |
ceacedba | 755 | #endif /* HAVE_CAPABILITIES */ |
01245821 | 756 | } |
757 | ||
758 | void | |
ceacedba | 759 | zprivs_terminate (struct zebra_privs_t *zprivs) |
01245821 | 760 | { |
ceacedba | 761 | if (!zprivs) |
01245821 | 762 | { |
ceacedba | 763 | fprintf (stderr, "%s: no privs struct given, terminating", __func__); |
764 | exit (0); | |
765 | } | |
01245821 | 766 | |
ceacedba | 767 | #ifdef HAVE_CAPABILITIES |
768 | zprivs_caps_terminate(); | |
769 | #else /* !HAVE_CAPABILITIES */ | |
01245821 | 770 | if (zprivs_state.zuid) |
771 | { | |
772 | if ( setreuid (zprivs_state.zuid, zprivs_state.zuid) ) | |
773 | { | |
ceacedba | 774 | fprintf (stderr, "privs_terminate: could not setreuid, %s", |
6099b3b5 | 775 | safe_strerror (errno) ); |
01245821 | 776 | exit (1); |
777 | } | |
778 | } | |
779 | #endif /* HAVE_LCAPS */ | |
ceacedba | 780 | |
781 | zprivs->change = zprivs_change_null; | |
782 | zprivs->current_state = zprivs_state_null; | |
783 | zprivs_null_state = ZPRIVS_LOWERED; | |
01245821 | 784 | return; |
785 | } | |
ba3a0bc5 | 786 | |
787 | void | |
788 | zprivs_get_ids(struct zprivs_ids_t *ids) | |
789 | { | |
790 | ||
791 | ids->uid_priv = getuid(); | |
792 | (zprivs_state.zuid) ? (ids->uid_normal = zprivs_state.zuid) | |
793 | : (ids->uid_normal = -1); | |
794 | (zprivs_state.zgid) ? (ids->gid_normal = zprivs_state.zgid) | |
795 | : (ids->gid_normal = -1); | |
796 | (zprivs_state.vtygrp) ? (ids->gid_vty = zprivs_state.vtygrp) | |
797 | : (ids->gid_vty = -1); | |
798 | ||
799 | return; | |
800 | } |