1 /*- 2 * Copyright (c) 1999-2002, 2009 Robert N. M. Watson 3 * Copyright (c) 2001 Ilmar S. Habibulin 4 * Copyright (c) 2001-2004 Networks Associates Technology, Inc. 5 * Copyright (c) 2006 SPARTA, Inc. 6 * Copyright (c) 2008 Apple Inc. 7 * All rights reserved. 8 * 9 * This software was developed by Robert Watson and Ilmar Habibulin for the 10 * TrustedBSD Project. 11 * 12 * This software was enhanced by SPARTA ISSO under SPAWAR contract 13 * N66001-04-C-6019 ("SEFOS"). 14 * 15 * This software was developed for the FreeBSD Project in part by Network 16 * Associates Laboratories, the Security Research Division of Network 17 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), 18 * as part of the DARPA CHATS research program. 19 * 20 * This software was developed at the University of Cambridge Computer 21 * Laboratory with support from a grant from Google, Inc. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the above copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_kdtrace.h" 49 #include "opt_mac.h" 50 51 #include <sys/param.h> 52 #include <sys/kernel.h> 53 #include <sys/lock.h> 54 #include <sys/malloc.h> 55 #include <sys/mutex.h> 56 #include <sys/mac.h> 57 #include <sys/priv.h> 58 #include <sys/sbuf.h> 59 #include <sys/sdt.h> 60 #include <sys/systm.h> 61 #include <sys/mount.h> 62 #include <sys/file.h> 63 #include <sys/namei.h> 64 #include <sys/protosw.h> 65 #include <sys/socket.h> 66 #include <sys/socketvar.h> 67 #include <sys/sysctl.h> 68 69 #include <net/bpfdesc.h> 70 #include <net/if.h> 71 #include <net/if_var.h> 72 73 #include <security/mac/mac_framework.h> 74 #include <security/mac/mac_internal.h> 75 #include <security/mac/mac_policy.h> 76 77 /* 78 * XXXRW: struct ifnet locking is incomplete in the network code, so we use 79 * our own global mutex for struct ifnet. Non-ideal, but should help in the 80 * SMP environment. 81 */ 82 struct mtx mac_ifnet_mtx; 83 MTX_SYSINIT(mac_ifnet_mtx, &mac_ifnet_mtx, "mac_ifnet", MTX_DEF); 84 85 /* 86 * Retrieve the label associated with an mbuf by searching for the tag. 87 * Depending on the value of mac_labelmbufs, it's possible that a label will 88 * not be present, in which case NULL is returned. Policies must handle the 89 * possibility of an mbuf not having label storage if they do not enforce 90 * early loading. 91 */ 92 struct label * 93 mac_mbuf_to_label(struct mbuf *m) 94 { 95 struct m_tag *tag; 96 struct label *label; 97 98 if (m == NULL) 99 return (NULL); 100 tag = m_tag_find(m, PACKET_TAG_MACLABEL, NULL); 101 if (tag == NULL) 102 return (NULL); 103 label = (struct label *)(tag+1); 104 return (label); 105 } 106 107 static struct label * 108 mac_bpfdesc_label_alloc(void) 109 { 110 struct label *label; 111 112 label = mac_labelzone_alloc(M_WAITOK); 113 MAC_POLICY_PERFORM(bpfdesc_init_label, label); 114 return (label); 115 } 116 117 void 118 mac_bpfdesc_init(struct bpf_d *d) 119 { 120 121 if (mac_labeled & MPC_OBJECT_BPFDESC) 122 d->bd_label = mac_bpfdesc_label_alloc(); 123 else 124 d->bd_label = NULL; 125 } 126 127 static struct label * 128 mac_ifnet_label_alloc(void) 129 { 130 struct label *label; 131 132 label = mac_labelzone_alloc(M_WAITOK); 133 MAC_POLICY_PERFORM(ifnet_init_label, label); 134 return (label); 135 } 136 137 void 138 mac_ifnet_init(struct ifnet *ifp) 139 { 140 141 if (mac_labeled & MPC_OBJECT_IFNET) 142 ifp->if_label = mac_ifnet_label_alloc(); 143 else 144 ifp->if_label = NULL; 145 } 146 147 int 148 mac_mbuf_tag_init(struct m_tag *tag, int flag) 149 { 150 struct label *label; 151 int error; 152 153 label = (struct label *) (tag + 1); 154 mac_init_label(label); 155 156 if (flag & M_WAITOK) 157 MAC_POLICY_CHECK(mbuf_init_label, label, flag); 158 else 159 MAC_POLICY_CHECK_NOSLEEP(mbuf_init_label, label, flag); 160 if (error) { 161 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label); 162 mac_destroy_label(label); 163 } 164 return (error); 165 } 166 167 int 168 mac_mbuf_init(struct mbuf *m, int flag) 169 { 170 struct m_tag *tag; 171 int error; 172 173 M_ASSERTPKTHDR(m); 174 175 if (mac_labeled & MPC_OBJECT_MBUF) { 176 tag = m_tag_get(PACKET_TAG_MACLABEL, sizeof(struct label), 177 flag); 178 if (tag == NULL) 179 return (ENOMEM); 180 error = mac_mbuf_tag_init(tag, flag); 181 if (error) { 182 m_tag_free(tag); 183 return (error); 184 } 185 m_tag_prepend(m, tag); 186 } 187 return (0); 188 } 189 190 static void 191 mac_bpfdesc_label_free(struct label *label) 192 { 193 194 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_destroy_label, label); 195 mac_labelzone_free(label); 196 } 197 198 void 199 mac_bpfdesc_destroy(struct bpf_d *d) 200 { 201 202 if (d->bd_label != NULL) { 203 mac_bpfdesc_label_free(d->bd_label); 204 d->bd_label = NULL; 205 } 206 } 207 208 static void 209 mac_ifnet_label_free(struct label *label) 210 { 211 212 MAC_POLICY_PERFORM_NOSLEEP(ifnet_destroy_label, label); 213 mac_labelzone_free(label); 214 } 215 216 void 217 mac_ifnet_destroy(struct ifnet *ifp) 218 { 219 220 if (ifp->if_label != NULL) { 221 mac_ifnet_label_free(ifp->if_label); 222 ifp->if_label = NULL; 223 } 224 } 225 226 void 227 mac_mbuf_tag_destroy(struct m_tag *tag) 228 { 229 struct label *label; 230 231 label = (struct label *)(tag+1); 232 233 MAC_POLICY_PERFORM_NOSLEEP(mbuf_destroy_label, label); 234 mac_destroy_label(label); 235 } 236 237 /* 238 * mac_mbuf_tag_copy is called when an mbuf header is duplicated, in which 239 * case the labels must also be duplicated. 240 */ 241 void 242 mac_mbuf_tag_copy(struct m_tag *src, struct m_tag *dest) 243 { 244 struct label *src_label, *dest_label; 245 246 src_label = (struct label *)(src+1); 247 dest_label = (struct label *)(dest+1); 248 249 /* 250 * mac_mbuf_tag_init() is called on the target tag in m_tag_copy(), 251 * so we don't need to call it here. 252 */ 253 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label); 254 } 255 256 void 257 mac_mbuf_copy(struct mbuf *m_from, struct mbuf *m_to) 258 { 259 struct label *src_label, *dest_label; 260 261 if (mac_policy_count == 0) 262 return; 263 264 src_label = mac_mbuf_to_label(m_from); 265 dest_label = mac_mbuf_to_label(m_to); 266 267 MAC_POLICY_PERFORM_NOSLEEP(mbuf_copy_label, src_label, dest_label); 268 } 269 270 static void 271 mac_ifnet_copy_label(struct label *src, struct label *dest) 272 { 273 274 MAC_POLICY_PERFORM_NOSLEEP(ifnet_copy_label, src, dest); 275 } 276 277 static int 278 mac_ifnet_externalize_label(struct label *label, char *elements, 279 char *outbuf, size_t outbuflen) 280 { 281 int error; 282 283 MAC_POLICY_EXTERNALIZE(ifnet, label, elements, outbuf, outbuflen); 284 285 return (error); 286 } 287 288 static int 289 mac_ifnet_internalize_label(struct label *label, char *string) 290 { 291 int error; 292 293 MAC_POLICY_INTERNALIZE(ifnet, label, string); 294 295 return (error); 296 } 297 298 void 299 mac_ifnet_create(struct ifnet *ifp) 300 { 301 302 if (mac_policy_count == 0) 303 return; 304 305 MAC_IFNET_LOCK(ifp); 306 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create, ifp, ifp->if_label); 307 MAC_IFNET_UNLOCK(ifp); 308 } 309 310 void 311 mac_bpfdesc_create(struct ucred *cred, struct bpf_d *d) 312 { 313 314 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create, cred, d, d->bd_label); 315 } 316 317 void 318 mac_bpfdesc_create_mbuf(struct bpf_d *d, struct mbuf *m) 319 { 320 struct label *label; 321 322 /* Assume reader lock is enough. */ 323 BPFD_LOCK_ASSERT(d); 324 325 if (mac_policy_count == 0) 326 return; 327 328 label = mac_mbuf_to_label(m); 329 330 MAC_POLICY_PERFORM_NOSLEEP(bpfdesc_create_mbuf, d, d->bd_label, m, 331 label); 332 } 333 334 void 335 mac_ifnet_create_mbuf(struct ifnet *ifp, struct mbuf *m) 336 { 337 struct label *label; 338 339 if (mac_policy_count == 0) 340 return; 341 342 label = mac_mbuf_to_label(m); 343 344 MAC_IFNET_LOCK(ifp); 345 MAC_POLICY_PERFORM_NOSLEEP(ifnet_create_mbuf, ifp, ifp->if_label, m, 346 label); 347 MAC_IFNET_UNLOCK(ifp); 348 } 349 350 MAC_CHECK_PROBE_DEFINE2(bpfdesc_check_receive, "struct bpf_d *", 351 "struct ifnet *"); 352 353 int 354 mac_bpfdesc_check_receive(struct bpf_d *d, struct ifnet *ifp) 355 { 356 int error; 357 358 /* Assume reader lock is enough. */ 359 BPFD_LOCK_ASSERT(d); 360 361 if (mac_policy_count == 0) 362 return (0); 363 364 MAC_IFNET_LOCK(ifp); 365 MAC_POLICY_CHECK_NOSLEEP(bpfdesc_check_receive, d, d->bd_label, ifp, 366 ifp->if_label); 367 MAC_CHECK_PROBE2(bpfdesc_check_receive, error, d, ifp); 368 MAC_IFNET_UNLOCK(ifp); 369 370 return (error); 371 } 372 373 MAC_CHECK_PROBE_DEFINE2(ifnet_check_transmit, "struct ifnet *", 374 "struct mbuf *"); 375 376 int 377 mac_ifnet_check_transmit(struct ifnet *ifp, struct mbuf *m) 378 { 379 struct label *label; 380 int error; 381 382 M_ASSERTPKTHDR(m); 383 384 if (mac_policy_count == 0) 385 return (0); 386 387 label = mac_mbuf_to_label(m); 388 389 MAC_IFNET_LOCK(ifp); 390 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_transmit, ifp, ifp->if_label, m, 391 label); 392 MAC_CHECK_PROBE2(ifnet_check_transmit, error, ifp, m); 393 MAC_IFNET_UNLOCK(ifp); 394 395 return (error); 396 } 397 398 int 399 mac_ifnet_ioctl_get(struct ucred *cred, struct ifreq *ifr, 400 struct ifnet *ifp) 401 { 402 char *elements, *buffer; 403 struct label *intlabel; 404 struct mac mac; 405 int error; 406 407 if (!(mac_labeled & MPC_OBJECT_IFNET)) 408 return (EINVAL); 409 410 error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac)); 411 if (error) 412 return (error); 413 414 error = mac_check_structmac_consistent(&mac); 415 if (error) 416 return (error); 417 418 elements = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK); 419 error = copyinstr(mac.m_string, elements, mac.m_buflen, NULL); 420 if (error) { 421 free(elements, M_MACTEMP); 422 return (error); 423 } 424 425 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK | M_ZERO); 426 intlabel = mac_ifnet_label_alloc(); 427 MAC_IFNET_LOCK(ifp); 428 mac_ifnet_copy_label(ifp->if_label, intlabel); 429 MAC_IFNET_UNLOCK(ifp); 430 error = mac_ifnet_externalize_label(intlabel, elements, buffer, 431 mac.m_buflen); 432 mac_ifnet_label_free(intlabel); 433 if (error == 0) 434 error = copyout(buffer, mac.m_string, strlen(buffer)+1); 435 436 free(buffer, M_MACTEMP); 437 free(elements, M_MACTEMP); 438 439 return (error); 440 } 441 442 int 443 mac_ifnet_ioctl_set(struct ucred *cred, struct ifreq *ifr, struct ifnet *ifp) 444 { 445 struct label *intlabel; 446 struct mac mac; 447 char *buffer; 448 int error; 449 450 if (!(mac_labeled & MPC_OBJECT_IFNET)) 451 return (EINVAL); 452 453 error = copyin(ifr->ifr_ifru.ifru_data, &mac, sizeof(mac)); 454 if (error) 455 return (error); 456 457 error = mac_check_structmac_consistent(&mac); 458 if (error) 459 return (error); 460 461 buffer = malloc(mac.m_buflen, M_MACTEMP, M_WAITOK); 462 error = copyinstr(mac.m_string, buffer, mac.m_buflen, NULL); 463 if (error) { 464 free(buffer, M_MACTEMP); 465 return (error); 466 } 467 468 intlabel = mac_ifnet_label_alloc(); 469 error = mac_ifnet_internalize_label(intlabel, buffer); 470 free(buffer, M_MACTEMP); 471 if (error) { 472 mac_ifnet_label_free(intlabel); 473 return (error); 474 } 475 476 /* 477 * XXX: Note that this is a redundant privilege check, since policies 478 * impose this check themselves if required by the policy 479 * Eventually, this should go away. 480 */ 481 error = priv_check_cred(cred, PRIV_NET_SETIFMAC, 0); 482 if (error) { 483 mac_ifnet_label_free(intlabel); 484 return (error); 485 } 486 487 MAC_IFNET_LOCK(ifp); 488 MAC_POLICY_CHECK_NOSLEEP(ifnet_check_relabel, cred, ifp, 489 ifp->if_label, intlabel); 490 if (error) { 491 MAC_IFNET_UNLOCK(ifp); 492 mac_ifnet_label_free(intlabel); 493 return (error); 494 } 495 496 MAC_POLICY_PERFORM_NOSLEEP(ifnet_relabel, cred, ifp, ifp->if_label, 497 intlabel); 498 MAC_IFNET_UNLOCK(ifp); 499 500 mac_ifnet_label_free(intlabel); 501 return (0); 502 } 503