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