ugidfw_system.c revision 156300
1/*- 2 * Copyright (c) 2005 Tom Rhodes 3 * Copyright (c) 1999-2002 Robert N. M. Watson 4 * Copyright (c) 2001-2005 Networks Associates Technology, Inc. 5 * All rights reserved. 6 * 7 * This software was developed by Robert Watson for the TrustedBSD Project. 8 * It was later enhanced by Tom Rhodes for the 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 * $FreeBSD: head/sys/security/mac_bsdextended/mac_bsdextended.c 156300 2006-03-04 20:47:19Z dwmalone $ 37 */ 38 39/* 40 * Developed by the TrustedBSD Project. 41 * "BSD Extended" MAC policy, allowing the administrator to impose 42 * mandatory rules regarding users and some system objects. 43 */ 44 45#include <sys/types.h> 46#include <sys/param.h> 47#include <sys/acl.h> 48#include <sys/conf.h> 49#include <sys/kernel.h> 50#include <sys/lock.h> 51#include <sys/mac.h> 52#include <sys/malloc.h> 53#include <sys/mount.h> 54#include <sys/mutex.h> 55#include <sys/proc.h> 56#include <sys/systm.h> 57#include <sys/sysproto.h> 58#include <sys/sysent.h> 59#include <sys/vnode.h> 60#include <sys/file.h> 61#include <sys/socket.h> 62#include <sys/socketvar.h> 63#include <sys/sysctl.h> 64#include <sys/syslog.h> 65 66#include <net/bpfdesc.h> 67#include <net/if.h> 68#include <net/if_types.h> 69#include <net/if_var.h> 70 71#include <vm/vm.h> 72 73#include <sys/mac_policy.h> 74 75#include <security/mac_bsdextended/mac_bsdextended.h> 76 77static struct mtx mac_bsdextended_mtx; 78 79SYSCTL_DECL(_security_mac); 80 81SYSCTL_NODE(_security_mac, OID_AUTO, bsdextended, CTLFLAG_RW, 0, 82 "TrustedBSD extended BSD MAC policy controls"); 83 84static int mac_bsdextended_enabled = 1; 85SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, enabled, CTLFLAG_RW, 86 &mac_bsdextended_enabled, 0, "Enforce extended BSD policy"); 87TUNABLE_INT("security.mac.bsdextended.enabled", &mac_bsdextended_enabled); 88 89MALLOC_DEFINE(M_MACBSDEXTENDED, "mac_bsdextended", "BSD Extended MAC rule"); 90 91#define MAC_BSDEXTENDED_MAXRULES 250 92static struct mac_bsdextended_rule *rules[MAC_BSDEXTENDED_MAXRULES]; 93static int rule_count = 0; 94static int rule_slots = 0; 95 96SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_count, CTLFLAG_RD, 97 &rule_count, 0, "Number of defined rules\n"); 98SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, rule_slots, CTLFLAG_RD, 99 &rule_slots, 0, "Number of used rule slots\n"); 100 101/* 102 * This is just used for logging purposes, eventually we would like 103 * to log much more then failed requests. 104 */ 105static int mac_bsdextended_logging; 106SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, logging, CTLFLAG_RW, 107 &mac_bsdextended_logging, 0, "Log failed authorization requests"); 108 109/* 110 * This tunable is here for compatibility. It will allow the user 111 * to switch between the new mode (first rule matches) and the old 112 * functionality (all rules match). 113 */ 114static int 115mac_bsdextended_firstmatch_enabled; 116SYSCTL_INT(_security_mac_bsdextended, OID_AUTO, firstmatch_enabled, 117 CTLFLAG_RW, &mac_bsdextended_firstmatch_enabled, 1, 118 "Disable/enable match first rule functionality"); 119 120static int 121mac_bsdextended_rule_valid(struct mac_bsdextended_rule *rule) 122{ 123 124 if ((rule->mbr_subject.mbi_flags | MBI_BITS) != MBI_BITS) 125 return (EINVAL); 126 127 if ((rule->mbr_object.mbi_flags | MBI_BITS) != MBI_BITS) 128 return (EINVAL); 129 130 if ((rule->mbr_mode | MBI_ALLPERM) != MBI_ALLPERM) 131 return (EINVAL); 132 133 return (0); 134} 135 136static int 137sysctl_rule(SYSCTL_HANDLER_ARGS) 138{ 139 struct mac_bsdextended_rule temprule, *ruleptr; 140 u_int namelen; 141 int error, index, *name; 142 143 error = 0; 144 name = (int *)arg1; 145 namelen = arg2; 146 147 /* printf("bsdextended sysctl handler (namelen %d)\n", namelen); */ 148 149 if (namelen != 1) 150 return (EINVAL); 151 152 index = name[0]; 153 if (index >= MAC_BSDEXTENDED_MAXRULES) 154 return (ENOENT); 155 156 ruleptr = NULL; 157 if (req->newptr && req->newlen != 0) { 158 error = SYSCTL_IN(req, &temprule, sizeof(temprule)); 159 if (error) 160 return (error); 161 MALLOC(ruleptr, struct mac_bsdextended_rule *, 162 sizeof(*ruleptr), M_MACBSDEXTENDED, M_WAITOK | M_ZERO); 163 } 164 165 mtx_lock(&mac_bsdextended_mtx); 166 167 if (req->oldptr) { 168 if (index < 0 || index > rule_slots + 1) { 169 error = ENOENT; 170 goto out; 171 } 172 if (rules[index] == NULL) { 173 error = ENOENT; 174 goto out; 175 } 176 temprule = *rules[index]; 177 } 178 179 if (req->newptr && req->newlen == 0) { 180 /* printf("deletion\n"); */ 181 KASSERT(ruleptr == NULL, ("sysctl_rule: ruleptr != NULL")); 182 ruleptr = rules[index]; 183 if (ruleptr == NULL) { 184 error = ENOENT; 185 goto out; 186 } 187 rule_count--; 188 rules[index] = NULL; 189 } else if (req->newptr) { 190 error = mac_bsdextended_rule_valid(&temprule); 191 if (error) 192 goto out; 193 194 if (rules[index] == NULL) { 195 /* printf("addition\n"); */ 196 *ruleptr = temprule; 197 rules[index] = ruleptr; 198 ruleptr = NULL; 199 if (index + 1 > rule_slots) 200 rule_slots = index + 1; 201 rule_count++; 202 } else { 203 /* printf("replacement\n"); */ 204 *rules[index] = temprule; 205 } 206 } 207 208out: 209 mtx_unlock(&mac_bsdextended_mtx); 210 if (ruleptr != NULL) 211 FREE(ruleptr, M_MACBSDEXTENDED); 212 if (req->oldptr && error == 0) 213 error = SYSCTL_OUT(req, &temprule, sizeof(temprule)); 214 215 return (error); 216} 217 218SYSCTL_NODE(_security_mac_bsdextended, OID_AUTO, rules, 219 CTLFLAG_RW, sysctl_rule, "BSD extended MAC rules"); 220 221static void 222mac_bsdextended_init(struct mac_policy_conf *mpc) 223{ 224 225 /* Initialize ruleset lock. */ 226 mtx_init(&mac_bsdextended_mtx, "mac_bsdextended lock", NULL, MTX_DEF); 227 228 /* Register dynamic sysctl's for rules. */ 229} 230 231static void 232mac_bsdextended_destroy(struct mac_policy_conf *mpc) 233{ 234 235 /* Destroy ruleset lock. */ 236 mtx_destroy(&mac_bsdextended_mtx); 237 238 /* Tear down sysctls. */ 239} 240 241static int 242mac_bsdextended_rulecheck(struct mac_bsdextended_rule *rule, 243 struct ucred *cred, uid_t object_uid, gid_t object_gid, int acc_mode) 244{ 245 int match; 246 247 /* 248 * Is there a subject match? 249 */ 250 mtx_assert(&mac_bsdextended_mtx, MA_OWNED); 251 if (rule->mbr_subject.mbi_flags & MBI_UID_DEFINED) { 252 match = (rule->mbr_subject.mbi_uid == cred->cr_uid || 253 rule->mbr_subject.mbi_uid == cred->cr_ruid || 254 rule->mbr_subject.mbi_uid == cred->cr_svuid); 255 256 if (rule->mbr_subject.mbi_flags & MBI_NEGATED) 257 match = !match; 258 259 if (!match) 260 return (0); 261 } 262 263 if (rule->mbr_subject.mbi_flags & MBI_GID_DEFINED) { 264 match = (groupmember(rule->mbr_subject.mbi_gid, cred) || 265 rule->mbr_subject.mbi_gid == cred->cr_rgid || 266 rule->mbr_subject.mbi_gid == cred->cr_svgid); 267 268 if (rule->mbr_subject.mbi_flags & MBI_NEGATED) 269 match = !match; 270 271 if (!match) 272 return (0); 273 } 274 275 /* 276 * Is there an object match? 277 */ 278 if (rule->mbr_object.mbi_flags & MBI_UID_DEFINED) { 279 match = (rule->mbr_object.mbi_uid == object_uid); 280 281 if (rule->mbr_object.mbi_flags & MBI_NEGATED) 282 match = !match; 283 284 if (!match) 285 return (0); 286 } 287 288 if (rule->mbr_object.mbi_flags & MBI_GID_DEFINED) { 289 match = (rule->mbr_object.mbi_gid == object_gid); 290 291 if (rule->mbr_object.mbi_flags & MBI_NEGATED) 292 match = !match; 293 294 if (!match) 295 return (0); 296 } 297 298 /* 299 * Is the access permitted? 300 */ 301 if ((rule->mbr_mode & acc_mode) != acc_mode) { 302 if (mac_bsdextended_logging) 303 log(LOG_AUTHPRIV, "mac_bsdextended: %d:%d request %d" 304 " on %d:%d failed. \n", cred->cr_ruid, 305 cred->cr_rgid, acc_mode, object_uid, object_gid); 306 return (EACCES); /* Matching rule denies access */ 307 } 308 309 /* 310 * If the rule matched, permits access, and first match is enabled, 311 * return success. 312 */ 313 if (mac_bsdextended_firstmatch_enabled) 314 return (EJUSTRETURN); 315 else 316 return(0); 317} 318 319static int 320mac_bsdextended_check(struct ucred *cred, uid_t object_uid, gid_t object_gid, 321 int acc_mode) 322{ 323 int error, i; 324 325 if (suser_cred(cred, 0) == 0) 326 return (0); 327 328 mtx_lock(&mac_bsdextended_mtx); 329 for (i = 0; i < rule_slots; i++) { 330 if (rules[i] == NULL) 331 continue; 332 333 /* 334 * Since we do not separately handle append, map append to 335 * write. 336 */ 337 if (acc_mode & MBI_APPEND) { 338 acc_mode &= ~MBI_APPEND; 339 acc_mode |= MBI_WRITE; 340 } 341 342 error = mac_bsdextended_rulecheck(rules[i], cred, object_uid, 343 object_gid, acc_mode); 344 if (error == EJUSTRETURN) 345 break; 346 if (error) { 347 mtx_unlock(&mac_bsdextended_mtx); 348 return (error); 349 } 350 } 351 mtx_unlock(&mac_bsdextended_mtx); 352 return (0); 353} 354 355static int 356mac_bsdextended_check_vp(struct ucred *cred, struct vnode *vp, int acc_mode) 357{ 358 int error; 359 struct vattr vap; 360 361 if (!mac_bsdextended_enabled) 362 return (0); 363 364 error = VOP_GETATTR(vp, &vap, cred, curthread); 365 if (error) 366 return (error); 367 368 return (mac_bsdextended_check(cred, vap.va_uid, vap.va_gid, 369 acc_mode)); 370} 371 372static int 373mac_bsdextended_check_system_swapon(struct ucred *cred, struct vnode *vp, 374 struct label *label) 375{ 376 377 return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE)); 378} 379 380static int 381mac_bsdextended_check_vnode_access(struct ucred *cred, struct vnode *vp, 382 struct label *label, int acc_mode) 383{ 384 385 return (mac_bsdextended_check_vp(cred, vp, acc_mode)); 386} 387 388static int 389mac_bsdextended_check_vnode_chdir(struct ucred *cred, struct vnode *dvp, 390 struct label *dlabel) 391{ 392 393 return (mac_bsdextended_check_vp(cred, dvp, MBI_EXEC)); 394} 395 396static int 397mac_bsdextended_check_vnode_chroot(struct ucred *cred, struct vnode *dvp, 398 struct label *dlabel) 399{ 400 401 return (mac_bsdextended_check_vp(cred, dvp, MBI_EXEC)); 402} 403 404static int 405mac_bsdextended_check_create_vnode(struct ucred *cred, struct vnode *dvp, 406 struct label *dlabel, struct componentname *cnp, struct vattr *vap) 407{ 408 409 return (mac_bsdextended_check_vp(cred, dvp, MBI_WRITE)); 410} 411 412static int 413mac_bsdextended_check_vnode_delete(struct ucred *cred, struct vnode *dvp, 414 struct label *dlabel, struct vnode *vp, struct label *label, 415 struct componentname *cnp) 416{ 417 int error; 418 419 error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE); 420 if (error) 421 return (error); 422 423 return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE)); 424} 425 426static int 427mac_bsdextended_check_vnode_deleteacl(struct ucred *cred, struct vnode *vp, 428 struct label *label, acl_type_t type) 429{ 430 431 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 432} 433 434static int 435mac_bsdextended_check_vnode_deleteextattr(struct ucred *cred, struct vnode *vp, 436 struct label *label, int attrnamespace, const char *name) 437{ 438 439 return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE)); 440} 441 442static int 443mac_bsdextended_check_vnode_exec(struct ucred *cred, struct vnode *vp, 444 struct label *label, struct image_params *imgp, 445 struct label *execlabel) 446{ 447 448 return (mac_bsdextended_check_vp(cred, vp, MBI_READ|MBI_EXEC)); 449} 450 451static int 452mac_bsdextended_check_vnode_getacl(struct ucred *cred, struct vnode *vp, 453 struct label *label, acl_type_t type) 454{ 455 456 return (mac_bsdextended_check_vp(cred, vp, MBI_STAT)); 457} 458 459static int 460mac_bsdextended_check_vnode_getextattr(struct ucred *cred, struct vnode *vp, 461 struct label *label, int attrnamespace, const char *name, struct uio *uio) 462{ 463 464 return (mac_bsdextended_check_vp(cred, vp, MBI_READ)); 465} 466 467static int 468mac_bsdextended_check_vnode_link(struct ucred *cred, struct vnode *dvp, 469 struct label *dlabel, struct vnode *vp, struct label *label, 470 struct componentname *cnp) 471{ 472 int error; 473 474 error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE); 475 if (error) 476 return (error); 477 478 error = mac_bsdextended_check_vp(cred, vp, MBI_WRITE); 479 if (error) 480 return (error); 481 return (0); 482} 483 484static int 485mac_bsdextended_check_vnode_listextattr(struct ucred *cred, struct vnode *vp, 486 struct label *label, int attrnamespace) 487{ 488 489 return (mac_bsdextended_check_vp(cred, vp, MBI_READ)); 490} 491 492static int 493mac_bsdextended_check_vnode_lookup(struct ucred *cred, struct vnode *dvp, 494 struct label *dlabel, struct componentname *cnp) 495{ 496 497 return (mac_bsdextended_check_vp(cred, dvp, MBI_EXEC)); 498} 499 500static int 501mac_bsdextended_check_vnode_open(struct ucred *cred, struct vnode *vp, 502 struct label *filelabel, int acc_mode) 503{ 504 505 return (mac_bsdextended_check_vp(cred, vp, acc_mode)); 506} 507 508static int 509mac_bsdextended_check_vnode_readdir(struct ucred *cred, struct vnode *dvp, 510 struct label *dlabel) 511{ 512 513 return (mac_bsdextended_check_vp(cred, dvp, MBI_READ)); 514} 515 516static int 517mac_bsdextended_check_vnode_readdlink(struct ucred *cred, struct vnode *vp, 518 struct label *label) 519{ 520 521 return (mac_bsdextended_check_vp(cred, vp, MBI_READ)); 522} 523 524static int 525mac_bsdextended_check_vnode_rename_from(struct ucred *cred, struct vnode *dvp, 526 struct label *dlabel, struct vnode *vp, struct label *label, 527 struct componentname *cnp) 528{ 529 int error; 530 531 error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE); 532 if (error) 533 return (error); 534 error = mac_bsdextended_check_vp(cred, vp, MBI_WRITE); 535 536 return (error); 537} 538 539static int 540mac_bsdextended_check_vnode_rename_to(struct ucred *cred, struct vnode *dvp, 541 struct label *dlabel, struct vnode *vp, struct label *label, int samedir, 542 struct componentname *cnp) 543{ 544 int error; 545 546 error = mac_bsdextended_check_vp(cred, dvp, MBI_WRITE); 547 if (error) 548 return (error); 549 550 if (vp != NULL) 551 error = mac_bsdextended_check_vp(cred, vp, MBI_WRITE); 552 553 return (error); 554} 555 556static int 557mac_bsdextended_check_vnode_revoke(struct ucred *cred, struct vnode *vp, 558 struct label *label) 559{ 560 561 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 562} 563 564static int 565mac_bsdextended_check_setacl_vnode(struct ucred *cred, struct vnode *vp, 566 struct label *label, acl_type_t type, struct acl *acl) 567{ 568 569 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 570} 571 572static int 573mac_bsdextended_check_vnode_setextattr(struct ucred *cred, struct vnode *vp, 574 struct label *label, int attrnamespace, const char *name, struct uio *uio) 575{ 576 577 return (mac_bsdextended_check_vp(cred, vp, MBI_WRITE)); 578} 579 580static int 581mac_bsdextended_check_vnode_setflags(struct ucred *cred, struct vnode *vp, 582 struct label *label, u_long flags) 583{ 584 585 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 586} 587 588static int 589mac_bsdextended_check_vnode_setmode(struct ucred *cred, struct vnode *vp, 590 struct label *label, mode_t mode) 591{ 592 593 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 594} 595 596static int 597mac_bsdextended_check_vnode_setowner(struct ucred *cred, struct vnode *vp, 598 struct label *label, uid_t uid, gid_t gid) 599{ 600 601 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 602} 603 604static int 605mac_bsdextended_check_vnode_setutimes(struct ucred *cred, struct vnode *vp, 606 struct label *label, struct timespec atime, struct timespec utime) 607{ 608 609 return (mac_bsdextended_check_vp(cred, vp, MBI_ADMIN)); 610} 611 612static int 613mac_bsdextended_check_vnode_stat(struct ucred *active_cred, 614 struct ucred *file_cred, struct vnode *vp, struct label *label) 615{ 616 617 return (mac_bsdextended_check_vp(active_cred, vp, MBI_STAT)); 618} 619 620static struct mac_policy_ops mac_bsdextended_ops = 621{ 622 .mpo_destroy = mac_bsdextended_destroy, 623 .mpo_init = mac_bsdextended_init, 624 .mpo_check_system_swapon = mac_bsdextended_check_system_swapon, 625 .mpo_check_vnode_access = mac_bsdextended_check_vnode_access, 626 .mpo_check_vnode_chdir = mac_bsdextended_check_vnode_chdir, 627 .mpo_check_vnode_chroot = mac_bsdextended_check_vnode_chroot, 628 .mpo_check_vnode_create = mac_bsdextended_check_create_vnode, 629 .mpo_check_vnode_delete = mac_bsdextended_check_vnode_delete, 630 .mpo_check_vnode_deleteacl = mac_bsdextended_check_vnode_deleteacl, 631 .mpo_check_vnode_deleteextattr = mac_bsdextended_check_vnode_deleteextattr, 632 .mpo_check_vnode_exec = mac_bsdextended_check_vnode_exec, 633 .mpo_check_vnode_getacl = mac_bsdextended_check_vnode_getacl, 634 .mpo_check_vnode_getextattr = mac_bsdextended_check_vnode_getextattr, 635 .mpo_check_vnode_link = mac_bsdextended_check_vnode_link, 636 .mpo_check_vnode_listextattr = mac_bsdextended_check_vnode_listextattr, 637 .mpo_check_vnode_lookup = mac_bsdextended_check_vnode_lookup, 638 .mpo_check_vnode_open = mac_bsdextended_check_vnode_open, 639 .mpo_check_vnode_readdir = mac_bsdextended_check_vnode_readdir, 640 .mpo_check_vnode_readlink = mac_bsdextended_check_vnode_readdlink, 641 .mpo_check_vnode_rename_from = mac_bsdextended_check_vnode_rename_from, 642 .mpo_check_vnode_rename_to = mac_bsdextended_check_vnode_rename_to, 643 .mpo_check_vnode_revoke = mac_bsdextended_check_vnode_revoke, 644 .mpo_check_vnode_setacl = mac_bsdextended_check_setacl_vnode, 645 .mpo_check_vnode_setextattr = mac_bsdextended_check_vnode_setextattr, 646 .mpo_check_vnode_setflags = mac_bsdextended_check_vnode_setflags, 647 .mpo_check_vnode_setmode = mac_bsdextended_check_vnode_setmode, 648 .mpo_check_vnode_setowner = mac_bsdextended_check_vnode_setowner, 649 .mpo_check_vnode_setutimes = mac_bsdextended_check_vnode_setutimes, 650 .mpo_check_vnode_stat = mac_bsdextended_check_vnode_stat, 651}; 652 653MAC_POLICY_SET(&mac_bsdextended_ops, mac_bsdextended, 654 "TrustedBSD MAC/BSD Extended", MPC_LOADTIME_FLAG_UNLOADOK, NULL); 655