sys/kern/subr_capability.c

   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_send_connect_rights;
  96 __read_mostly cap_rights_t cap_setsockopt_rights;
  97 __read_mostly cap_rights_t cap_shutdown_rights;
  98 __read_mostly cap_rights_t cap_symlinkat_rights;
  99 __read_mostly cap_rights_t cap_unlinkat_rights;
 100 __read_mostly cap_rights_t cap_write_rights;
 101 __read_mostly cap_rights_t cap_no_rights;
 102
 103 static void
 104 cap_rights_sysinit(void *arg)
 105 {
 106         cap_rights_init_one(&cap_accept_rights, CAP_ACCEPT);
 107         cap_rights_init_one(&cap_bind_rights, CAP_BIND);
 108         cap_rights_init_one(&cap_connect_rights, CAP_CONNECT);
 109         cap_rights_init_one(&cap_event_rights, CAP_EVENT);
 110         cap_rights_init_one(&cap_fchdir_rights, CAP_FCHDIR);
 111         cap_rights_init_one(&cap_fchflags_rights, CAP_FCHFLAGS);
 112         cap_rights_init_one(&cap_fchmod_rights, CAP_FCHMOD);
 113         cap_rights_init_one(&cap_fchown_rights, CAP_FCHOWN);
 114         cap_rights_init_one(&cap_fcntl_rights, CAP_FCNTL);
 115         cap_rights_init_one(&cap_fexecve_rights, CAP_FEXECVE);
 116         cap_rights_init_one(&cap_flock_rights, CAP_FLOCK);
 117         cap_rights_init_one(&cap_fpathconf_rights, CAP_FPATHCONF);
 118         cap_rights_init_one(&cap_fstat_rights, CAP_FSTAT);
 119         cap_rights_init_one(&cap_fstatfs_rights, CAP_FSTATFS);
 120         cap_rights_init_one(&cap_fsync_rights, CAP_FSYNC);
 121         cap_rights_init_one(&cap_ftruncate_rights, CAP_FTRUNCATE);
 122         cap_rights_init_one(&cap_futimes_rights, CAP_FUTIMES);
 123         cap_rights_init_one(&cap_getpeername_rights, CAP_GETPEERNAME);
 124         cap_rights_init_one(&cap_getsockname_rights, CAP_GETSOCKNAME);
 125         cap_rights_init_one(&cap_getsockopt_rights, CAP_GETSOCKOPT);
 126         cap_rights_init_one(&cap_ioctl_rights, CAP_IOCTL);
 127         cap_rights_init_one(&cap_linkat_source_rights, CAP_LINKAT_SOURCE);
 128         cap_rights_init_one(&cap_linkat_target_rights, CAP_LINKAT_TARGET);
 129         cap_rights_init_one(&cap_listen_rights, CAP_LISTEN);
 130         cap_rights_init_one(&cap_mkdirat_rights, CAP_MKDIRAT);
 131         cap_rights_init_one(&cap_mkfifoat_rights, CAP_MKFIFOAT);
 132         cap_rights_init_one(&cap_mknodat_rights, CAP_MKNODAT);
 133         cap_rights_init_one(&cap_mmap_rights, CAP_MMAP);
 134         cap_rights_init_one(&cap_pdgetpid_rights, CAP_PDGETPID);
 135         cap_rights_init_one(&cap_pdkill_rights, CAP_PDKILL);
 136         cap_rights_init_one(&cap_pread_rights, CAP_PREAD);
 137         cap_rights_init_one(&cap_pwrite_rights, CAP_PWRITE);
 138         cap_rights_init_one(&cap_read_rights, CAP_READ);
 139         cap_rights_init_one(&cap_recv_rights, CAP_RECV);
 140         cap_rights_init_one(&cap_renameat_source_rights, CAP_RENAMEAT_SOURCE);
 141         cap_rights_init_one(&cap_renameat_target_rights, CAP_RENAMEAT_TARGET);
 142         cap_rights_init_one(&cap_seek_rights, CAP_SEEK);
 143         cap_rights_init_one(&cap_send_rights, CAP_SEND);
 144         cap_rights_init(&cap_send_connect_rights, CAP_SEND, CAP_CONNECT);
 145         cap_rights_init_one(&cap_setsockopt_rights, CAP_SETSOCKOPT);
 146         cap_rights_init_one(&cap_shutdown_rights, CAP_SHUTDOWN);
 147         cap_rights_init_one(&cap_symlinkat_rights, CAP_SYMLINKAT);
 148         cap_rights_init_one(&cap_unlinkat_rights, CAP_UNLINKAT);
 149         cap_rights_init_one(&cap_write_rights, CAP_WRITE);
 150         cap_rights_init(&cap_no_rights);
 151 }
 152 SYSINIT(cap_rights_sysinit, SI_SUB_COPYRIGHT, SI_ORDER_ANY, cap_rights_sysinit,
 153     NULL);
 154
 155 #endif
 156
 157 #define CAPARSIZE_MIN   (CAP_RIGHTS_VERSION_00 + 2)
 158 #define CAPARSIZE_MAX   (CAP_RIGHTS_VERSION + 2)
 159
 160 static __inline int
 161 right_to_index(uint64_t right)
 162 {
 163         static const int bit2idx[] = {
 164                 -1, 0, 1, -1, 2, -1, -1, -1, 3, -1, -1, -1, -1, -1, -1, -1,
 165                 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
 166         };
 167         int idx;
 168
 169         idx = CAPIDXBIT(right);
 170         assert(idx >= 0 && idx < sizeof(bit2idx) / sizeof(bit2idx[0]));
 171         return (bit2idx[idx]);
 172 }
 173
 174 static void
 175 cap_rights_vset(cap_rights_t *rights, va_list ap)
 176 {
 177         uint64_t right;
 178         int i, n __unused;
 179
 180         assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
 181
 182         n = CAPARSIZE(rights);
 183         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 184
 185         for (;;) {
 186                 right = (uint64_t)va_arg(ap, unsigned long long);
 187                 if (right == 0)
 188                         break;
 189                 assert(CAPRVER(right) == 0);
 190                 i = right_to_index(right);
 191                 assert(i >= 0);
 192                 assert(i < n);
 193                 assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
 194                 rights->cr_rights[i] |= right;
 195                 assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
 196         }
 197 }
 198
 199 static void
 200 cap_rights_vclear(cap_rights_t *rights, va_list ap)
 201 {
 202         uint64_t right;
 203         int i, n __unused;
 204
 205         assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
 206
 207         n = CAPARSIZE(rights);
 208         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 209
 210         for (;;) {
 211                 right = (uint64_t)va_arg(ap, unsigned long long);
 212                 if (right == 0)
 213                         break;
 214                 assert(CAPRVER(right) == 0);
 215                 i = right_to_index(right);
 216                 assert(i >= 0);
 217                 assert(i < n);
 218                 assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
 219                 rights->cr_rights[i] &= ~(right & 0x01FFFFFFFFFFFFFFULL);
 220                 assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
 221         }
 222 }
 223
 224 static bool
 225 cap_rights_is_vset(const cap_rights_t *rights, va_list ap)
 226 {
 227         uint64_t right;
 228         int i, n __unused;
 229
 230         assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
 231
 232         n = CAPARSIZE(rights);
 233         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 234
 235         for (;;) {
 236                 right = (uint64_t)va_arg(ap, unsigned long long);
 237                 if (right == 0)
 238                         break;
 239                 assert(CAPRVER(right) == 0);
 240                 i = right_to_index(right);
 241                 assert(i >= 0);
 242                 assert(i < n);
 243                 assert(CAPIDXBIT(rights->cr_rights[i]) == CAPIDXBIT(right));
 244                 if ((rights->cr_rights[i] & right) != right)
 245                         return (false);
 246         }
 247
 248         return (true);
 249 }
 250
 251 cap_rights_t *
 252 __cap_rights_init(int version, cap_rights_t *rights, ...)
 253 {
 254         unsigned int n __unused;
 255         va_list ap;
 256
 257         assert(version == CAP_RIGHTS_VERSION_00);
 258
 259         n = version + 2;
 260         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 261         CAP_NONE(rights);
 262         va_start(ap, rights);
 263         cap_rights_vset(rights, ap);
 264         va_end(ap);
 265
 266         return (rights);
 267 }
 268
 269 cap_rights_t *
 270 __cap_rights_set(cap_rights_t *rights, ...)
 271 {
 272         va_list ap;
 273
 274         assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
 275
 276         va_start(ap, rights);
 277         cap_rights_vset(rights, ap);
 278         va_end(ap);
 279
 280         return (rights);
 281 }
 282
 283 cap_rights_t *
 284 __cap_rights_clear(cap_rights_t *rights, ...)
 285 {
 286         va_list ap;
 287
 288         assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
 289
 290         va_start(ap, rights);
 291         cap_rights_vclear(rights, ap);
 292         va_end(ap);
 293
 294         return (rights);
 295 }
 296
 297 bool
 298 __cap_rights_is_set(const cap_rights_t *rights, ...)
 299 {
 300         va_list ap;
 301         bool ret;
 302
 303         assert(CAPVER(rights) == CAP_RIGHTS_VERSION_00);
 304
 305         va_start(ap, rights);
 306         ret = cap_rights_is_vset(rights, ap);
 307         va_end(ap);
 308
 309         return (ret);
 310 }
 311
 312 bool
 313 cap_rights_is_valid(const cap_rights_t *rights)
 314 {
 315         cap_rights_t allrights;
 316         int i, j;
 317
 318         if (CAPVER(rights) != CAP_RIGHTS_VERSION_00)
 319                 return (false);
 320         if (CAPARSIZE(rights) < CAPARSIZE_MIN ||
 321             CAPARSIZE(rights) > CAPARSIZE_MAX) {
 322                 return (false);
 323         }
 324         CAP_ALL(&allrights);
 325         if (!cap_rights_contains(&allrights, rights))
 326                 return (false);
 327         for (i = 0; i < CAPARSIZE(rights); i++) {
 328                 j = right_to_index(rights->cr_rights[i]);
 329                 if (i != j)
 330                         return (false);
 331                 if (i > 0) {
 332                         if (CAPRVER(rights->cr_rights[i]) != 0)
 333                                 return (false);
 334                 }
 335         }
 336
 337         return (true);
 338 }
 339
 340 cap_rights_t *
 341 cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src)
 342 {
 343         unsigned int i, n;
 344
 345         assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00);
 346         assert(CAPVER(src) == CAP_RIGHTS_VERSION_00);
 347         assert(CAPVER(dst) == CAPVER(src));
 348         assert(cap_rights_is_valid(src));
 349         assert(cap_rights_is_valid(dst));
 350
 351         n = CAPARSIZE(dst);
 352         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 353
 354         for (i = 0; i < n; i++)
 355                 dst->cr_rights[i] |= src->cr_rights[i];
 356
 357         assert(cap_rights_is_valid(src));
 358         assert(cap_rights_is_valid(dst));
 359
 360         return (dst);
 361 }
 362
 363 cap_rights_t *
 364 cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src)
 365 {
 366         unsigned int i, n;
 367
 368         assert(CAPVER(dst) == CAP_RIGHTS_VERSION_00);
 369         assert(CAPVER(src) == CAP_RIGHTS_VERSION_00);
 370         assert(CAPVER(dst) == CAPVER(src));
 371         assert(cap_rights_is_valid(src));
 372         assert(cap_rights_is_valid(dst));
 373
 374         n = CAPARSIZE(dst);
 375         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 376
 377         for (i = 0; i < n; i++) {
 378                 dst->cr_rights[i] &=
 379                     ~(src->cr_rights[i] & 0x01FFFFFFFFFFFFFFULL);
 380         }
 381
 382         assert(cap_rights_is_valid(src));
 383         assert(cap_rights_is_valid(dst));
 384
 385         return (dst);
 386 }
 387
 388 #ifndef _KERNEL
 389 bool
 390 cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little)
 391 {
 392         unsigned int i, n;
 393
 394         assert(CAPVER(big) == CAP_RIGHTS_VERSION_00);
 395         assert(CAPVER(little) == CAP_RIGHTS_VERSION_00);
 396         assert(CAPVER(big) == CAPVER(little));
 397
 398         n = CAPARSIZE(big);
 399         assert(n >= CAPARSIZE_MIN && n <= CAPARSIZE_MAX);
 400
 401         for (i = 0; i < n; i++) {
 402                 if ((big->cr_rights[i] & little->cr_rights[i]) !=
 403                     little->cr_rights[i]) {
 404                         return (false);
 405                 }
 406         }
 407
 408         return (true);
 409 }
 410 #endif