1 /*- 2 * Copyright (c) 1999-2002 Robert N. M. Watson 3 * Copyright (c) 2001 Ilmar S. Habibulin 4 * Copyright (c) 2001-2004 Networks Associates Technology, Inc. 5 * All rights reserved. 6 * 7 * This software was developed by Robert Watson and Ilmar Habibulin for the 8 * TrustedBSD Project. 9 * 10 * This software was developed for the FreeBSD Project in part by Network 11 * Associates Laboratories, the Security Research Division of Network 12 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 13 * as part of the DARPA CHATS research program. 14 * 15 * Redistribution and use in source and binary forms, with or without 16 * modification, are permitted provided that the following conditions 17 * are met: 18 * 1. Redistributions of source code must retain the above copyright 19 * notice, this list of conditions and the following disclaimer. 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in the 22 * documentation and/or other materials provided with the distribution. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_mac.h" 41 42 #include <sys/param.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/mutex.h> 47 #include <sys/mac.h> 48 #include <sys/sbuf.h> 49 #include <sys/systm.h> 50 #include <sys/mount.h> 51 #include <sys/file.h> 52 #include <sys/namei.h> 53 #include <sys/protosw.h> 54 #include <sys/socket.h> 55 #include <sys/socketvar.h> 56 #include <sys/sysctl.h> 57 58 #include <sys/mac_policy.h> 59 60 #include <net/bpfdesc.h> 61 #include <net/if.h> 62 #include <net/if_var.h> 63 64 #include <netinet/in.h> 65 #include <netinet/in_pcb.h> 66 #include <netinet/ip_var.h> 67 68 #include <security/mac/mac_internal.h> 69 70 /* 71 * mac_enforce_socket is used by the inet code when delivering to an inpcb 72 * without hitting the socket layer, and has to be non-static for now. 73 */ 74 int mac_enforce_socket = 1; 75 SYSCTL_INT(_security_mac, OID_AUTO, enforce_socket, CTLFLAG_RW, 76 &mac_enforce_socket, 0, "Enforce MAC policy on socket operations"); 77 TUNABLE_INT("security.mac.enforce_socket", &mac_enforce_socket); 78 79 #ifdef MAC_DEBUG 80 static unsigned int nmacsockets; 81 82 SYSCTL_UINT(_security_mac_debug_counters, OID_AUTO, sockets, CTLFLAG_RD, 83 &nmacsockets, 0, "number of sockets in use"); 84 #endif 85 86 struct label * 87 mac_socket_label_alloc(int flag) 88 { 89 struct label *label; 90 int error; 91 92 label = mac_labelzone_alloc(flag); 93 if (label == NULL) 94 return (NULL); 95 96 MAC_CHECK(init_socket_label, label, flag); 97 if (error) { 98 MAC_PERFORM(destroy_socket_label, label); 99 mac_labelzone_free(label); 100 return (NULL); 101 } 102 MAC_DEBUG_COUNTER_INC(&nmacsockets); 103 return (label); 104 } 105 106 static struct label * 107 mac_socket_peer_label_alloc(int flag) 108 { 109 struct label *label; 110 int error; 111 112 label = mac_labelzone_alloc(flag); 113 if (label == NULL) 114 return (NULL); 115 116 MAC_CHECK(init_socket_peer_label, label, flag); 117 if (error) { 118 MAC_PERFORM(destroy_socket_peer_label, label); 119 mac_labelzone_free(label); 120 return (NULL); 121 } 122 MAC_DEBUG_COUNTER_INC(&nmacsockets); 123 return (label); 124 } 125 126 int 127 mac_init_socket(struct socket *so, int flag) 128 { 129 130 so->so_label = mac_socket_label_alloc(flag); 131 if (so->so_label == NULL) 132 return (ENOMEM); 133 so->so_peerlabel = mac_socket_peer_label_alloc(flag); 134 if (so->so_peerlabel == NULL) { 135 mac_socket_label_free(so->so_label); 136 so->so_label = NULL; 137 return (ENOMEM); 138 } 139 return (0); 140 } 141 142 void 143 mac_socket_label_free(struct label *label) 144 { 145 146 MAC_PERFORM(destroy_socket_label, label); 147 mac_labelzone_free(label); 148 MAC_DEBUG_COUNTER_DEC(&nmacsockets); 149 } 150 151 static void 152 mac_socket_peer_label_free(struct label *label) 153 { 154 155 MAC_PERFORM(destroy_socket_peer_label, label); 156 mac_labelzone_free(label); 157 MAC_DEBUG_COUNTER_DEC(&nmacsockets); 158 } 159 160 void 161 mac_destroy_socket(struct socket *socket) 162 { 163 164 mac_socket_label_free(socket->so_label); 165 socket->so_label = NULL; 166 mac_socket_peer_label_free(socket->so_peerlabel); 167 socket->so_peerlabel = NULL; 168 } 169 170 void 171 mac_copy_socket_label(struct label *src, struct label *dest) 172 { 173 174 MAC_PERFORM(copy_socket_label, src, dest); 175 } 176 177 int 178 mac_externalize_socket_label(struct label *label, char *elements, 179 char *outbuf, size_t outbuflen) 180 { 181 int error; 182 183 MAC_EXTERNALIZE(socket, label, elements, outbuf, outbuflen); 184 185 return (error); 186 } 187 188 static int 189 mac_externalize_socket_peer_label(struct label *label, char *elements, 190 char *outbuf, size_t outbuflen) 191 { 192 int error; 193 194 MAC_EXTERNALIZE(socket_peer, label, elements, outbuf, outbuflen); 195 196 return (error); 197 } 198 199 int 200 mac_internalize_socket_label(struct label *label, char *string) 201 { 202 int error; 203 204 MAC_INTERNALIZE(socket, label, string); 205 206 return (error); 207 } 208 209 void 210 mac_create_socket(struct ucred *cred, struct socket *socket) 211 { 212 213 MAC_PERFORM(create_socket, cred, socket, socket->so_label); 214 } 215 216 void 217 mac_create_socket_from_socket(struct socket *oldsocket, 218 struct socket *newsocket) 219 { 220 221 SOCK_LOCK_ASSERT(oldsocket); 222 MAC_PERFORM(create_socket_from_socket, oldsocket, oldsocket->so_label, 223 newsocket, newsocket->so_label); 224 } 225 226 static void 227 mac_relabel_socket(struct ucred *cred, struct socket *socket, 228 struct label *newlabel) 229 { 230 231 SOCK_LOCK_ASSERT(socket); 232 MAC_PERFORM(relabel_socket, cred, socket, socket->so_label, newlabel); 233 } 234 235 void 236 mac_set_socket_peer_from_mbuf(struct mbuf *mbuf, struct socket *socket) 237 { 238 struct label *label; 239 240 SOCK_LOCK_ASSERT(socket); 241 242 label = mac_mbuf_to_label(mbuf); 243 244 MAC_PERFORM(set_socket_peer_from_mbuf, mbuf, label, socket, 245 socket->so_peerlabel); 246 } 247 248 void 249 mac_set_socket_peer_from_socket(struct socket *oldsocket, 250 struct socket *newsocket) 251 { 252 253 /* 254 * XXXRW: only hold the socket lock on one at a time, as one 255 * socket is the original, and one is the new. However, it's 256 * called in both directions, so we can't assert the lock 257 * here currently. 258 */ 259 MAC_PERFORM(set_socket_peer_from_socket, oldsocket, 260 oldsocket->so_label, newsocket, newsocket->so_peerlabel); 261 } 262 263 void 264 mac_create_mbuf_from_socket(struct socket *socket, struct mbuf *mbuf) 265 { 266 struct label *label; 267 268 label = mac_mbuf_to_label(mbuf); 269 270 SOCK_LOCK_ASSERT(socket); 271 MAC_PERFORM(create_mbuf_from_socket, socket, socket->so_label, mbuf, 272 label); 273 } 274 275 int 276 mac_check_socket_bind(struct ucred *ucred, struct socket *socket, 277 struct sockaddr *sockaddr) 278 { 279 int error; 280 281 SOCK_LOCK_ASSERT(socket); 282 283 if (!mac_enforce_socket) 284 return (0); 285 286 MAC_CHECK(check_socket_bind, ucred, socket, socket->so_label, 287 sockaddr); 288 289 return (error); 290 } 291 292 int 293 mac_check_socket_connect(struct ucred *cred, struct socket *socket, 294 struct sockaddr *sockaddr) 295 { 296 int error; 297 298 SOCK_LOCK_ASSERT(socket); 299 300 if (!mac_enforce_socket) 301 return (0); 302 303 MAC_CHECK(check_socket_connect, cred, socket, socket->so_label, 304 sockaddr); 305 306 return (error); 307 } 308 309 int 310 mac_check_socket_deliver(struct socket *socket, struct mbuf *mbuf) 311 { 312 struct label *label; 313 int error; 314 315 SOCK_LOCK_ASSERT(socket); 316 317 if (!mac_enforce_socket) 318 return (0); 319 320 label = mac_mbuf_to_label(mbuf); 321 322 MAC_CHECK(check_socket_deliver, socket, socket->so_label, mbuf, 323 label); 324 325 return (error); 326 } 327 328 int 329 mac_check_socket_listen(struct ucred *cred, struct socket *socket) 330 { 331 int error; 332 333 SOCK_LOCK_ASSERT(socket); 334 335 if (!mac_enforce_socket) 336 return (0); 337 338 MAC_CHECK(check_socket_listen, cred, socket, socket->so_label); 339 return (error); 340 } 341 342 int 343 mac_check_socket_receive(struct ucred *cred, struct socket *so) 344 { 345 int error; 346 347 SOCK_LOCK_ASSERT(so); 348 349 if (!mac_enforce_socket) 350 return (0); 351 352 MAC_CHECK(check_socket_receive, cred, so, so->so_label); 353 354 return (error); 355 } 356 357 static int 358 mac_check_socket_relabel(struct ucred *cred, struct socket *socket, 359 struct label *newlabel) 360 { 361 int error; 362 363 SOCK_LOCK_ASSERT(socket); 364 365 MAC_CHECK(check_socket_relabel, cred, socket, socket->so_label, 366 newlabel); 367 368 return (error); 369 } 370 371 int 372 mac_check_socket_send(struct ucred *cred, struct socket *so) 373 { 374 int error; 375 376 SOCK_LOCK_ASSERT(so); 377 378 if (!mac_enforce_socket) 379 return (0); 380 381 MAC_CHECK(check_socket_send, cred, so, so->so_label); 382 383 return (error); 384 } 385 386 int 387 mac_check_socket_visible(struct ucred *cred, struct socket *socket) 388 { 389 int error; 390 391 SOCK_LOCK_ASSERT(socket); 392 393 if (!mac_enforce_socket) 394 return (0); 395 396 MAC_CHECK(check_socket_visible, cred, socket, socket->so_label); 397 398 return (error); 399 } 400 401 int 402 mac_socket_label_set(struct ucred *cred, struct socket *so, 403 struct label *label) 404 { 405 int error; 406 407 /* 408 * We acquire the socket lock when we perform the test and set, 409 * but have to release it as the pcb code needs to acquire the 410 * pcb lock, which will precede the socket lock in the lock 411 * order. However, this is fine, as any race will simply 412 * result in the inpcb being refreshed twice, but still 413 * consistently, as the inpcb code will acquire the socket lock 414 * before refreshing, holding both locks. 415 */ 416 SOCK_LOCK(so); 417 error = mac_check_socket_relabel(cred, so, label); 418 if (error) { 419 SOCK_UNLOCK(so); 420 return (error); 421 } 422 423 mac_relabel_socket(cred, so, label); 424 SOCK_UNLOCK(so); 425 /* 426 * If the protocol has expressed interest in socket layer changes, 427 * such as if it needs to propagate changes to a cached pcb 428 * label from the socket, notify it of the label change while 429 * holding the socket lock. 430 */ 431 if (so->so_proto->pr_usrreqs->pru_sosetlabel != NULL) 432 (so->so_proto->pr_usrreqs->pru_sosetlabel)(so); 433 434 return (0); 435 } 436 437 int 438 mac_setsockopt_label(struct ucred *cred, struct socket *so, struct mac *mac) 439 { 440 struct label *intlabel; 441 char *buffer; 442 int error; 443 444 error = mac_check_structmac_consistent(mac); 445 if (error) 446 return (error); 447 448 buffer = malloc(mac->m_buflen, M_MACTEMP, M_WAITOK); 449 error = copyinstr(mac->m_string, buffer, mac->m_buflen, NULL); 450 if (error) { 451 free(buffer, M_MACTEMP); 452 return (error); 453 } 454 455 intlabel = mac_socket_label_alloc(M_WAITOK); 456 error = mac_internalize_socket_label(intlabel, buffer); 457 free(buffer, M_MACTEMP); 458 if (error) 459 goto out; 460 461 error = mac_socket_label_set(cred, so, intlabel); 462 out: 463 mac_socket_label_free(intlabel); 464 return (error); 465 } 466 467 int 468 mac_getsockopt_label(struct ucred *cred, struct socket *so, struct mac *mac) 469 { 470 char *buffer, *elements; 471 struct label *intlabel; 472 int error; 473 474 error = mac_check_structmac_consistent(mac); 475 if (error) 476 return (error); 477 478 elements = malloc(mac->m_buflen, M_MACTEMP, M_WAITOK); 479 error = copyinstr(mac->m_string, elements, mac->m_buflen, NULL); 480 if (error) { 481 free(elements, M_MACTEMP); 482 return (error); 483 } 484 485 buffer = malloc(mac->m_buflen, M_MACTEMP, M_WAITOK | M_ZERO); 486 intlabel = mac_socket_label_alloc(M_WAITOK); 487 SOCK_LOCK(so); 488 mac_copy_socket_label(so->so_label, intlabel); 489 SOCK_UNLOCK(so); 490 error = mac_externalize_socket_label(intlabel, elements, buffer, 491 mac->m_buflen); 492 mac_socket_label_free(intlabel); 493 if (error == 0) 494 error = copyout(buffer, mac->m_string, strlen(buffer)+1); 495 496 free(buffer, M_MACTEMP); 497 free(elements, M_MACTEMP); 498 499 return (error); 500 } 501 502 int 503 mac_getsockopt_peerlabel(struct ucred *cred, struct socket *so, 504 struct mac *mac) 505 { 506 char *elements, *buffer; 507 struct label *intlabel; 508 int error; 509 510 error = mac_check_structmac_consistent(mac); 511 if (error) 512 return (error); 513 514 elements = malloc(mac->m_buflen, M_MACTEMP, M_WAITOK); 515 error = copyinstr(mac->m_string, elements, mac->m_buflen, NULL); 516 if (error) { 517 free(elements, M_MACTEMP); 518 return (error); 519 } 520 521 buffer = malloc(mac->m_buflen, M_MACTEMP, M_WAITOK | M_ZERO); 522 intlabel = mac_socket_label_alloc(M_WAITOK); 523 SOCK_LOCK(so); 524 mac_copy_socket_label(so->so_peerlabel, intlabel); 525 SOCK_UNLOCK(so); 526 error = mac_externalize_socket_peer_label(intlabel, elements, buffer, 527 mac->m_buflen); 528 mac_socket_label_free(intlabel); 529 if (error == 0) 530 error = copyout(buffer, mac->m_string, strlen(buffer)+1); 531 532 free(buffer, M_MACTEMP); 533 free(elements, M_MACTEMP); 534 535 return (error); 536 } 537