xref: /freebsd/sys/kern/subr_capability.c (revision a665699823a2099a451e1c9c1505ef1cbf29c914)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013 FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Pawel Jakub Dawidek under sponsorship from
8  * the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 /*
36  * Note that this file is compiled into the kernel and into libc.
37  */
38 
39 #include <sys/types.h>
40 #include <sys/capsicum.h>
41 
42 #ifdef _KERNEL
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <machine/stdarg.h>
46 #else	/* !_KERNEL */
47 #include <assert.h>
48 #include <stdarg.h>
49 #include <stdbool.h>
50 #include <stdint.h>
51 #include <string.h>
52 #endif
53 
54 #ifdef _KERNEL
55 #define	assert(exp)	KASSERT((exp), ("%s:%u", __func__, __LINE__))
56 __read_mostly cap_rights_t cap_accept_rights;
57 __read_mostly cap_rights_t cap_bind_rights;
58 __read_mostly cap_rights_t cap_chflags_rights;
59 __read_mostly cap_rights_t cap_connect_rights;
60 __read_mostly cap_rights_t cap_event_rights;
61 __read_mostly cap_rights_t cap_fchdir_rights;
62 __read_mostly cap_rights_t cap_fchflags_rights;
63 __read_mostly cap_rights_t cap_fchmod_rights;
64 __read_mostly cap_rights_t cap_fchown_rights;
65 __read_mostly cap_rights_t cap_fcntl_rights;
66 __read_mostly cap_rights_t cap_fexecve_rights;
67 __read_mostly cap_rights_t cap_flock_rights;
68 __read_mostly cap_rights_t cap_fpathconf_rights;
69 __read_mostly cap_rights_t cap_fstat_rights;
70 __read_mostly cap_rights_t cap_fstatfs_rights;
71 __read_mostly cap_rights_t cap_fsync_rights;
72 __read_mostly cap_rights_t cap_ftruncate_rights;
73 __read_mostly cap_rights_t cap_futimes_rights;
74 __read_mostly cap_rights_t cap_getpeername_rights;
75 __read_mostly cap_rights_t cap_getsockopt_rights;
76 __read_mostly cap_rights_t cap_getsockname_rights;
77 __read_mostly cap_rights_t cap_ioctl_rights;
78 __read_mostly cap_rights_t cap_listen_rights;
79 __read_mostly cap_rights_t cap_linkat_source_rights;
80 __read_mostly cap_rights_t cap_linkat_target_rights;
81 __read_mostly cap_rights_t cap_mmap_rights;
82 __read_mostly cap_rights_t cap_mkdirat_rights;
83 __read_mostly cap_rights_t cap_mkfifoat_rights;
84 __read_mostly cap_rights_t cap_mknodat_rights;
85 __read_mostly cap_rights_t cap_pdgetpid_rights;
86 __read_mostly cap_rights_t cap_pdkill_rights;
87 __read_mostly cap_rights_t cap_pread_rights;
88 __read_mostly cap_rights_t cap_pwrite_rights;
89 __read_mostly cap_rights_t cap_read_rights;
90 __read_mostly cap_rights_t cap_recv_rights;
91 __read_mostly cap_rights_t cap_renameat_source_rights;
92 __read_mostly cap_rights_t cap_renameat_target_rights;
93 __read_mostly cap_rights_t cap_seek_rights;
94 __read_mostly cap_rights_t cap_send_rights;
95 __read_mostly cap_rights_t cap_setsockopt_rights;
96 __read_mostly cap_rights_t cap_shutdown_rights;
97 __read_mostly cap_rights_t cap_symlinkat_rights;
98 __read_mostly cap_rights_t cap_unlinkat_rights;
99 __read_mostly cap_rights_t cap_write_rights;
100 __read_mostly cap_rights_t cap_no_rights;
101 
102 static void
103 __cap_rights_sysinit1(void *arg)
104 {
105 	cap_rights_init(&cap_accept_rights, CAP_ACCEPT);
106 	cap_rights_init(&cap_bind_rights, CAP_BIND);
107 	cap_rights_init(&cap_connect_rights, CAP_CONNECT);
108 	cap_rights_init(&cap_event_rights, CAP_EVENT);
109 	cap_rights_init(&cap_fchdir_rights, CAP_FCHDIR);
110 	cap_rights_init(&cap_fchflags_rights, CAP_FCHFLAGS);
111 	cap_rights_init(&cap_fchmod_rights, CAP_FCHMOD);
112 	cap_rights_init(&cap_fchown_rights, CAP_FCHOWN);
113 	cap_rights_init(&cap_fcntl_rights, CAP_FCNTL);
114 	cap_rights_init(&cap_fexecve_rights, CAP_FEXECVE);
115 	cap_rights_init(&cap_flock_rights, CAP_FLOCK);
116 	cap_rights_init(&cap_fpathconf_rights, CAP_FPATHCONF);
117 	cap_rights_init(&cap_fstat_rights, CAP_FSTAT);
118 	cap_rights_init(&cap_fstatfs_rights, CAP_FSTATFS);
119 	cap_rights_init(&cap_fsync_rights, CAP_FSYNC);
120 	cap_rights_init(&cap_ftruncate_rights, CAP_FTRUNCATE);
121 	cap_rights_init(&cap_futimes_rights, CAP_FUTIMES);
122 	cap_rights_init(&cap_getpeername_rights, CAP_GETPEERNAME);
123 	cap_rights_init(&cap_getsockname_rights, CAP_GETSOCKNAME);
124 	cap_rights_init(&cap_getsockopt_rights, CAP_GETSOCKOPT);
125 	cap_rights_init(&cap_ioctl_rights, CAP_IOCTL);
126 	cap_rights_init(&cap_linkat_source_rights, CAP_LINKAT_SOURCE);
127 	cap_rights_init(&cap_linkat_target_rights, CAP_LINKAT_TARGET);
128 	cap_rights_init(&cap_listen_rights, CAP_LISTEN);
129 	cap_rights_init(&cap_mkdirat_rights, CAP_MKDIRAT);
130 	cap_rights_init(&cap_mkfifoat_rights, CAP_MKFIFOAT);
131 	cap_rights_init(&cap_mknodat_rights, CAP_MKNODAT);
132 	cap_rights_init(&cap_mmap_rights, CAP_MMAP);
133 	cap_rights_init(&cap_pdgetpid_rights, CAP_PDGETPID);
134 	cap_rights_init(&cap_pdkill_rights, CAP_PDKILL);
135 	cap_rights_init(&cap_pread_rights, CAP_PREAD);
136 	cap_rights_init(&cap_pwrite_rights, CAP_PWRITE);
137 	cap_rights_init(&cap_read_rights, CAP_READ);
138 	cap_rights_init(&cap_recv_rights, CAP_RECV);
139 	cap_rights_init(&cap_renameat_source_rights, CAP_RENAMEAT_SOURCE);
140 	cap_rights_init(&cap_renameat_target_rights, CAP_RENAMEAT_TARGET);
141 	cap_rights_init(&cap_seek_rights, CAP_SEEK);
142 	cap_rights_init(&cap_send_rights, CAP_SEND);
143 	cap_rights_init(&cap_setsockopt_rights, CAP_SETSOCKOPT);
144 	cap_rights_init(&cap_shutdown_rights, CAP_SHUTDOWN);
145 	cap_rights_init(&cap_symlinkat_rights, CAP_SYMLINKAT);
146 	cap_rights_init(&cap_unlinkat_rights, CAP_UNLINKAT);
147 	cap_rights_init(&cap_write_rights, CAP_WRITE);
148 	cap_rights_init(&cap_no_rights);
149 }
150 SYSINIT(cap_rights1_sysinit, SI_SUB_COPYRIGHT, SI_ORDER_ANY,	\
151 		    __cap_rights_sysinit1, NULL);
152 
153 #endif
154 
155 #define	CAPARSIZE_MIN	(CAP_RIGHTS_VERSION_00 + 2)
156 #define	CAPARSIZE_MAX	(CAP_RIGHTS_VERSION + 2)
157 
158 static __inline int
159 right_to_index(uint64_t right)
160 {
161 	static const int bit2idx[] = {
162 		-1, 0, 1, -1, 2, -1, -1, -1, 3, -1, -1, -1, -1, -1, -1, -1,
163 		4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
164 	};
165 	int idx;
166 
167 	idx = CAPIDXBIT(right);
168 	assert(idx >= 0 && idx < sizeof(bit2idx) / sizeof(bit2idx[0]));
169 	return (bit2idx[idx]);
170 }
171 
172 static void
173 cap_rights_vset(cap_rights_t *rights, va_list ap)
174 {
175 	uint64_t right;
176 	int i, n __unused;
177 
178 	assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
179 
180 	n = CAPARSIZE(rights);
181 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
182 
183 	for (;;) {
184 		right = (uint64_t)va_arg(ap, unsigned long long);
185 		if (right == 0)
186 			break;
187 		assert(CAPRVER(right) == 0);
188 		i = right_to_index(right);
189 		assert(i >= 0);
190 		assert(i < n);
191 		assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
192 		rights->cr_rights[i] |= right;
193 		assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
194 	}
195 }
196 
197 static void
198 cap_rights_vclear(cap_rights_t *rights, va_list ap)
199 {
200 	uint64_t right;
201 	int i, n __unused;
202 
203 	assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
204 
205 	n = CAPARSIZE(rights);
206 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
207 
208 	for (;;) {
209 		right = (uint64_t)va_arg(ap, unsigned long long);
210 		if (right == 0)
211 			break;
212 		assert(CAPRVER(right) == 0);
213 		i = right_to_index(right);
214 		assert(i >= 0);
215 		assert(i < n);
216 		assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
217 		rights->cr_rights[i] &= ~(right & 0x01FFFFFFFFFFFFFFULL);
218 		assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
219 	}
220 }
221 
222 static bool
223 cap_rights_is_vset(const cap_rights_t *rights, va_list ap)
224 {
225 	uint64_t right;
226 	int i, n __unused;
227 
228 	assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
229 
230 	n = CAPARSIZE(rights);
231 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
232 
233 	for (;;) {
234 		right = (uint64_t)va_arg(ap, unsigned long long);
235 		if (right == 0)
236 			break;
237 		assert(CAPRVER(right) == 0);
238 		i = right_to_index(right);
239 		assert(i >= 0);
240 		assert(i < n);
241 		assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
242 		if ((rights->cr_rights[i] & right) != right)
243 			return (false);
244 	}
245 
246 	return (true);
247 }
248 
249 void
250 __cap_rights_sysinit(void *arg)
251 {
252 	struct cap_rights_init_args *cria = arg;
253 	cap_rights_t *rights = cria->cria_rights;
254 
255 	__cap_rights_init(CAP_RIGHTS_VERSION, rights, cria->cria_value1,
256        cria->cria_value2, cria->cria_value3, cria->cria_value4, 0ULL);
257 }
258 
259 cap_rights_t *
260 __cap_rights_init(int version, cap_rights_t *rights, ...)
261 {
262 	unsigned int n __unused;
263 	va_list ap;
264 
265 	assert(version == CAP_RIGHTS_VERSION_00);
266 
267 	n = version + 2;
268 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
269 	CAP_NONE(rights);
270 	va_start(ap, rights);
271 	cap_rights_vset(rights, ap);
272 	va_end(ap);
273 
274 	return (rights);
275 }
276 
277 cap_rights_t *
278 __cap_rights_set(cap_rights_t *rights, ...)
279 {
280 	va_list ap;
281 
282 	assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
283 
284 	va_start(ap, rights);
285 	cap_rights_vset(rights, ap);
286 	va_end(ap);
287 
288 	return (rights);
289 }
290 
291 cap_rights_t *
292 __cap_rights_clear(cap_rights_t *rights, ...)
293 {
294 	va_list ap;
295 
296 	assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
297 
298 	va_start(ap, rights);
299 	cap_rights_vclear(rights, ap);
300 	va_end(ap);
301 
302 	return (rights);
303 }
304 
305 bool
306 __cap_rights_is_set(const cap_rights_t *rights, ...)
307 {
308 	va_list ap;
309 	bool ret;
310 
311 	assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
312 
313 	va_start(ap, rights);
314 	ret = cap_rights_is_vset(rights, ap);
315 	va_end(ap);
316 
317 	return (ret);
318 }
319 
320 bool
321 cap_rights_is_valid(const cap_rights_t *rights)
322 {
323 	cap_rights_t allrights;
324 	int i, j;
325 
326 	if (CAPVER(rights) != CAP_RIGHTS_VERSION_00)
327 		return (false);
328 	if (CAPARSIZE(rights) < CAPARSIZE_MIN ||
329 	    CAPARSIZE(rights) > CAPARSIZE_MAX) {
330 		return (false);
331 	}
332 	CAP_ALL(&allrights);
333 	if (!cap_rights_contains(&allrights, rights))
334 		return (false);
335 	for (i = 0; i < CAPARSIZE(rights); i++) {
336 		j = right_to_index(rights->cr_rights[i]);
337 		if (i != j)
338 			return (false);
339 		if (i > 0) {
340 			if (CAPRVER(rights->cr_rights[i]) != 0)
341 				return (false);
342 		}
343 	}
344 
345 	return (true);
346 }
347 
348 cap_rights_t *
349 cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src)
350 {
351 	unsigned int i, n;
352 
353 	assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00);
354 	assert(CAPVER(src) == CAP_RIGHTS_VERSION_00);
355 	assert(CAPVER(dst) == CAPVER(src));
356 	assert(cap_rights_is_valid(src));
357 	assert(cap_rights_is_valid(dst));
358 
359 	n = CAPARSIZE(dst);
360 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
361 
362 	for (i = 0; i < n; i++)
363 		dst->cr_rights[i] |= src->cr_rights[i];
364 
365 	assert(cap_rights_is_valid(src));
366 	assert(cap_rights_is_valid(dst));
367 
368 	return (dst);
369 }
370 
371 cap_rights_t *
372 cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src)
373 {
374 	unsigned int i, n;
375 
376 	assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00);
377 	assert(CAPVER(src) == CAP_RIGHTS_VERSION_00);
378 	assert(CAPVER(dst) == CAPVER(src));
379 	assert(cap_rights_is_valid(src));
380 	assert(cap_rights_is_valid(dst));
381 
382 	n = CAPARSIZE(dst);
383 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
384 
385 	for (i = 0; i < n; i++) {
386 		dst->cr_rights[i] &=
387 		    ~(src->cr_rights[i] & 0x01FFFFFFFFFFFFFFULL);
388 	}
389 
390 	assert(cap_rights_is_valid(src));
391 	assert(cap_rights_is_valid(dst));
392 
393 	return (dst);
394 }
395 
396 bool
397 cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little)
398 {
399 	unsigned int i, n;
400 
401 	assert(CAPVER(big) == CAP_RIGHTS_VERSION_00);
402 	assert(CAPVER(little) == CAP_RIGHTS_VERSION_00);
403 	assert(CAPVER(big) == CAPVER(little));
404 
405 	n = CAPARSIZE(big);
406 	assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
407 
408 	for (i = 0; i < n; i++) {
409 		if ((big->cr_rights[i] & little->cr_rights[i]) !=
410 		    little->cr_rights[i]) {
411 			return (false);
412 		}
413 	}
414 
415 	return (true);
416 }
417