linux/security/selinux/ss/services.c
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   1/*
   2 * Implementation of the security services.
   3 *
   4 * Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
   5 *           James Morris <jmorris@redhat.com>
   6 *
   7 * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
   8 *
   9 *      Support for enhanced MLS infrastructure.
  10 *      Support for context based audit filters.
  11 *
  12 * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
  13 *
  14 *      Added conditional policy language extensions
  15 *
  16 * Updated: Hewlett-Packard <paul.moore@hp.com>
  17 *
  18 *      Added support for NetLabel
  19 *
  20 * Updated: Chad Sellers <csellers@tresys.com>
  21 *
  22 *  Added validation of kernel classes and permissions
  23 *
  24 * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
  25 * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  26 * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  27 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
  28 *      This program is free software; you can redistribute it and/or modify
  29 *      it under the terms of the GNU General Public License as published by
  30 *      the Free Software Foundation, version 2.
  31 */
  32#include <linux/kernel.h>
  33#include <linux/slab.h>
  34#include <linux/string.h>
  35#include <linux/spinlock.h>
  36#include <linux/rcupdate.h>
  37#include <linux/errno.h>
  38#include <linux/in.h>
  39#include <linux/sched.h>
  40#include <linux/audit.h>
  41#include <linux/mutex.h>
  42#include <net/netlabel.h>
  43
  44#include "flask.h"
  45#include "avc.h"
  46#include "avc_ss.h"
  47#include "security.h"
  48#include "context.h"
  49#include "policydb.h"
  50#include "sidtab.h"
  51#include "services.h"
  52#include "conditional.h"
  53#include "mls.h"
  54#include "objsec.h"
  55#include "netlabel.h"
  56#include "xfrm.h"
  57#include "ebitmap.h"
  58
  59extern void selnl_notify_policyload(u32 seqno);
  60unsigned int policydb_loaded_version;
  61
  62/*
  63 * This is declared in avc.c
  64 */
  65extern const struct selinux_class_perm selinux_class_perm;
  66
  67static DEFINE_RWLOCK(policy_rwlock);
  68#define POLICY_RDLOCK read_lock(&policy_rwlock)
  69#define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
  70#define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
  71#define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
  72
  73static DEFINE_MUTEX(load_mutex);
  74#define LOAD_LOCK mutex_lock(&load_mutex)
  75#define LOAD_UNLOCK mutex_unlock(&load_mutex)
  76
  77static struct sidtab sidtab;
  78struct policydb policydb;
  79int ss_initialized = 0;
  80
  81/*
  82 * The largest sequence number that has been used when
  83 * providing an access decision to the access vector cache.
  84 * The sequence number only changes when a policy change
  85 * occurs.
  86 */
  87static u32 latest_granting = 0;
  88
  89/* Forward declaration. */
  90static int context_struct_to_string(struct context *context, char **scontext,
  91                                    u32 *scontext_len);
  92
  93/*
  94 * Return the boolean value of a constraint expression
  95 * when it is applied to the specified source and target
  96 * security contexts.
  97 *
  98 * xcontext is a special beast...  It is used by the validatetrans rules
  99 * only.  For these rules, scontext is the context before the transition,
 100 * tcontext is the context after the transition, and xcontext is the context
 101 * of the process performing the transition.  All other callers of
 102 * constraint_expr_eval should pass in NULL for xcontext.
 103 */
 104static int constraint_expr_eval(struct context *scontext,
 105                                struct context *tcontext,
 106                                struct context *xcontext,
 107                                struct constraint_expr *cexpr)
 108{
 109        u32 val1, val2;
 110        struct context *c;
 111        struct role_datum *r1, *r2;
 112        struct mls_level *l1, *l2;
 113        struct constraint_expr *e;
 114        int s[CEXPR_MAXDEPTH];
 115        int sp = -1;
 116
 117        for (e = cexpr; e; e = e->next) {
 118                switch (e->expr_type) {
 119                case CEXPR_NOT:
 120                        BUG_ON(sp < 0);
 121                        s[sp] = !s[sp];
 122                        break;
 123                case CEXPR_AND:
 124                        BUG_ON(sp < 1);
 125                        sp--;
 126                        s[sp] &= s[sp+1];
 127                        break;
 128                case CEXPR_OR:
 129                        BUG_ON(sp < 1);
 130                        sp--;
 131                        s[sp] |= s[sp+1];
 132                        break;
 133                case CEXPR_ATTR:
 134                        if (sp == (CEXPR_MAXDEPTH-1))
 135                                return 0;
 136                        switch (e->attr) {
 137                        case CEXPR_USER:
 138                                val1 = scontext->user;
 139                                val2 = tcontext->user;
 140                                break;
 141                        case CEXPR_TYPE:
 142                                val1 = scontext->type;
 143                                val2 = tcontext->type;
 144                                break;
 145                        case CEXPR_ROLE:
 146                                val1 = scontext->role;
 147                                val2 = tcontext->role;
 148                                r1 = policydb.role_val_to_struct[val1 - 1];
 149                                r2 = policydb.role_val_to_struct[val2 - 1];
 150                                switch (e->op) {
 151                                case CEXPR_DOM:
 152                                        s[++sp] = ebitmap_get_bit(&r1->dominates,
 153                                                                  val2 - 1);
 154                                        continue;
 155                                case CEXPR_DOMBY:
 156                                        s[++sp] = ebitmap_get_bit(&r2->dominates,
 157                                                                  val1 - 1);
 158                                        continue;
 159                                case CEXPR_INCOMP:
 160                                        s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
 161                                                                     val2 - 1) &&
 162                                                    !ebitmap_get_bit(&r2->dominates,
 163                                                                     val1 - 1) );
 164                                        continue;
 165                                default:
 166                                        break;
 167                                }
 168                                break;
 169                        case CEXPR_L1L2:
 170                                l1 = &(scontext->range.level[0]);
 171                                l2 = &(tcontext->range.level[0]);
 172                                goto mls_ops;
 173                        case CEXPR_L1H2:
 174                                l1 = &(scontext->range.level[0]);
 175                                l2 = &(tcontext->range.level[1]);
 176                                goto mls_ops;
 177                        case CEXPR_H1L2:
 178                                l1 = &(scontext->range.level[1]);
 179                                l2 = &(tcontext->range.level[0]);
 180                                goto mls_ops;
 181                        case CEXPR_H1H2:
 182                                l1 = &(scontext->range.level[1]);
 183                                l2 = &(tcontext->range.level[1]);
 184                                goto mls_ops;
 185                        case CEXPR_L1H1:
 186                                l1 = &(scontext->range.level[0]);
 187                                l2 = &(scontext->range.level[1]);
 188                                goto mls_ops;
 189                        case CEXPR_L2H2:
 190                                l1 = &(tcontext->range.level[0]);
 191                                l2 = &(tcontext->range.level[1]);
 192                                goto mls_ops;
 193mls_ops:
 194                        switch (e->op) {
 195                        case CEXPR_EQ:
 196                                s[++sp] = mls_level_eq(l1, l2);
 197                                continue;
 198                        case CEXPR_NEQ:
 199                                s[++sp] = !mls_level_eq(l1, l2);
 200                                continue;
 201                        case CEXPR_DOM:
 202                                s[++sp] = mls_level_dom(l1, l2);
 203                                continue;
 204                        case CEXPR_DOMBY:
 205                                s[++sp] = mls_level_dom(l2, l1);
 206                                continue;
 207                        case CEXPR_INCOMP:
 208                                s[++sp] = mls_level_incomp(l2, l1);
 209                                continue;
 210                        default:
 211                                BUG();
 212                                return 0;
 213                        }
 214                        break;
 215                        default:
 216                                BUG();
 217                                return 0;
 218                        }
 219
 220                        switch (e->op) {
 221                        case CEXPR_EQ:
 222                                s[++sp] = (val1 == val2);
 223                                break;
 224                        case CEXPR_NEQ:
 225                                s[++sp] = (val1 != val2);
 226                                break;
 227                        default:
 228                                BUG();
 229                                return 0;
 230                        }
 231                        break;
 232                case CEXPR_NAMES:
 233                        if (sp == (CEXPR_MAXDEPTH-1))
 234                                return 0;
 235                        c = scontext;
 236                        if (e->attr & CEXPR_TARGET)
 237                                c = tcontext;
 238                        else if (e->attr & CEXPR_XTARGET) {
 239                                c = xcontext;
 240                                if (!c) {
 241                                        BUG();
 242                                        return 0;
 243                                }
 244                        }
 245                        if (e->attr & CEXPR_USER)
 246                                val1 = c->user;
 247                        else if (e->attr & CEXPR_ROLE)
 248                                val1 = c->role;
 249                        else if (e->attr & CEXPR_TYPE)
 250                                val1 = c->type;
 251                        else {
 252                                BUG();
 253                                return 0;
 254                        }
 255
 256                        switch (e->op) {
 257                        case CEXPR_EQ:
 258                                s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
 259                                break;
 260                        case CEXPR_NEQ:
 261                                s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
 262                                break;
 263                        default:
 264                                BUG();
 265                                return 0;
 266                        }
 267                        break;
 268                default:
 269                        BUG();
 270                        return 0;
 271                }
 272        }
 273
 274        BUG_ON(sp != 0);
 275        return s[0];
 276}
 277
 278/*
 279 * Compute access vectors based on a context structure pair for
 280 * the permissions in a particular class.
 281 */
 282static int context_struct_compute_av(struct context *scontext,
 283                                     struct context *tcontext,
 284                                     u16 tclass,
 285                                     u32 requested,
 286                                     struct av_decision *avd)
 287{
 288        struct constraint_node *constraint;
 289        struct role_allow *ra;
 290        struct avtab_key avkey;
 291        struct avtab_node *node;
 292        struct class_datum *tclass_datum;
 293        struct ebitmap *sattr, *tattr;
 294        struct ebitmap_node *snode, *tnode;
 295        const struct selinux_class_perm *kdefs = &selinux_class_perm;
 296        unsigned int i, j;
 297
 298        /*
 299         * Remap extended Netlink classes for old policy versions.
 300         * Do this here rather than socket_type_to_security_class()
 301         * in case a newer policy version is loaded, allowing sockets
 302         * to remain in the correct class.
 303         */
 304        if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 305                if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 306                    tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 307                        tclass = SECCLASS_NETLINK_SOCKET;
 308
 309        /*
 310         * Initialize the access vectors to the default values.
 311         */
 312        avd->allowed = 0;
 313        avd->decided = 0xffffffff;
 314        avd->auditallow = 0;
 315        avd->auditdeny = 0xffffffff;
 316        avd->seqno = latest_granting;
 317
 318        /*
 319         * Check for all the invalid cases.
 320         * - tclass 0
 321         * - tclass > policy and > kernel
 322         * - tclass > policy but is a userspace class
 323         * - tclass > policy but we do not allow unknowns
 324         */
 325        if (unlikely(!tclass))
 326                goto inval_class;
 327        if (unlikely(tclass > policydb.p_classes.nprim))
 328                if (tclass > kdefs->cts_len ||
 329                    !kdefs->class_to_string[tclass - 1] ||
 330                    !policydb.allow_unknown)
 331                        goto inval_class;
 332
 333        /*
 334         * Kernel class and we allow unknown so pad the allow decision
 335         * the pad will be all 1 for unknown classes.
 336         */
 337        if (tclass <= kdefs->cts_len && policydb.allow_unknown)
 338                avd->allowed = policydb.undefined_perms[tclass - 1];
 339
 340        /*
 341         * Not in policy. Since decision is completed (all 1 or all 0) return.
 342         */
 343        if (unlikely(tclass > policydb.p_classes.nprim))
 344                return 0;
 345
 346        tclass_datum = policydb.class_val_to_struct[tclass - 1];
 347
 348        /*
 349         * If a specific type enforcement rule was defined for
 350         * this permission check, then use it.
 351         */
 352        avkey.target_class = tclass;
 353        avkey.specified = AVTAB_AV;
 354        sattr = &policydb.type_attr_map[scontext->type - 1];
 355        tattr = &policydb.type_attr_map[tcontext->type - 1];
 356        ebitmap_for_each_positive_bit(sattr, snode, i) {
 357                ebitmap_for_each_positive_bit(tattr, tnode, j) {
 358                        avkey.source_type = i + 1;
 359                        avkey.target_type = j + 1;
 360                        for (node = avtab_search_node(&policydb.te_avtab, &avkey);
 361                             node != NULL;
 362                             node = avtab_search_node_next(node, avkey.specified)) {
 363                                if (node->key.specified == AVTAB_ALLOWED)
 364                                        avd->allowed |= node->datum.data;
 365                                else if (node->key.specified == AVTAB_AUDITALLOW)
 366                                        avd->auditallow |= node->datum.data;
 367                                else if (node->key.specified == AVTAB_AUDITDENY)
 368                                        avd->auditdeny &= node->datum.data;
 369                        }
 370
 371                        /* Check conditional av table for additional permissions */
 372                        cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
 373
 374                }
 375        }
 376
 377        /*
 378         * Remove any permissions prohibited by a constraint (this includes
 379         * the MLS policy).
 380         */
 381        constraint = tclass_datum->constraints;
 382        while (constraint) {
 383                if ((constraint->permissions & (avd->allowed)) &&
 384                    !constraint_expr_eval(scontext, tcontext, NULL,
 385                                          constraint->expr)) {
 386                        avd->allowed = (avd->allowed) & ~(constraint->permissions);
 387                }
 388                constraint = constraint->next;
 389        }
 390
 391        /*
 392         * If checking process transition permission and the
 393         * role is changing, then check the (current_role, new_role)
 394         * pair.
 395         */
 396        if (tclass == SECCLASS_PROCESS &&
 397            (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
 398            scontext->role != tcontext->role) {
 399                for (ra = policydb.role_allow; ra; ra = ra->next) {
 400                        if (scontext->role == ra->role &&
 401                            tcontext->role == ra->new_role)
 402                                break;
 403                }
 404                if (!ra)
 405                        avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
 406                                                        PROCESS__DYNTRANSITION);
 407        }
 408
 409        return 0;
 410
 411inval_class:
 412        printk(KERN_ERR "%s:  unrecognized class %d\n", __FUNCTION__, tclass);
 413        return -EINVAL;
 414}
 415
 416static int security_validtrans_handle_fail(struct context *ocontext,
 417                                           struct context *ncontext,
 418                                           struct context *tcontext,
 419                                           u16 tclass)
 420{
 421        char *o = NULL, *n = NULL, *t = NULL;
 422        u32 olen, nlen, tlen;
 423
 424        if (context_struct_to_string(ocontext, &o, &olen) < 0)
 425                goto out;
 426        if (context_struct_to_string(ncontext, &n, &nlen) < 0)
 427                goto out;
 428        if (context_struct_to_string(tcontext, &t, &tlen) < 0)
 429                goto out;
 430        audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 431                  "security_validate_transition:  denied for"
 432                  " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
 433                  o, n, t, policydb.p_class_val_to_name[tclass-1]);
 434out:
 435        kfree(o);
 436        kfree(n);
 437        kfree(t);
 438
 439        if (!selinux_enforcing)
 440                return 0;
 441        return -EPERM;
 442}
 443
 444int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 445                                 u16 tclass)
 446{
 447        struct context *ocontext;
 448        struct context *ncontext;
 449        struct context *tcontext;
 450        struct class_datum *tclass_datum;
 451        struct constraint_node *constraint;
 452        int rc = 0;
 453
 454        if (!ss_initialized)
 455                return 0;
 456
 457        POLICY_RDLOCK;
 458
 459        /*
 460         * Remap extended Netlink classes for old policy versions.
 461         * Do this here rather than socket_type_to_security_class()
 462         * in case a newer policy version is loaded, allowing sockets
 463         * to remain in the correct class.
 464         */
 465        if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
 466                if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
 467                    tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
 468                        tclass = SECCLASS_NETLINK_SOCKET;
 469
 470        if (!tclass || tclass > policydb.p_classes.nprim) {
 471                printk(KERN_ERR "security_validate_transition:  "
 472                       "unrecognized class %d\n", tclass);
 473                rc = -EINVAL;
 474                goto out;
 475        }
 476        tclass_datum = policydb.class_val_to_struct[tclass - 1];
 477
 478        ocontext = sidtab_search(&sidtab, oldsid);
 479        if (!ocontext) {
 480                printk(KERN_ERR "security_validate_transition: "
 481                       " unrecognized SID %d\n", oldsid);
 482                rc = -EINVAL;
 483                goto out;
 484        }
 485
 486        ncontext = sidtab_search(&sidtab, newsid);
 487        if (!ncontext) {
 488                printk(KERN_ERR "security_validate_transition: "
 489                       " unrecognized SID %d\n", newsid);
 490                rc = -EINVAL;
 491                goto out;
 492        }
 493
 494        tcontext = sidtab_search(&sidtab, tasksid);
 495        if (!tcontext) {
 496                printk(KERN_ERR "security_validate_transition: "
 497                       " unrecognized SID %d\n", tasksid);
 498                rc = -EINVAL;
 499                goto out;
 500        }
 501
 502        constraint = tclass_datum->validatetrans;
 503        while (constraint) {
 504                if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 505                                          constraint->expr)) {
 506                        rc = security_validtrans_handle_fail(ocontext, ncontext,
 507                                                             tcontext, tclass);
 508                        goto out;
 509                }
 510                constraint = constraint->next;
 511        }
 512
 513out:
 514        POLICY_RDUNLOCK;
 515        return rc;
 516}
 517
 518/**
 519 * security_compute_av - Compute access vector decisions.
 520 * @ssid: source security identifier
 521 * @tsid: target security identifier
 522 * @tclass: target security class
 523 * @requested: requested permissions
 524 * @avd: access vector decisions
 525 *
 526 * Compute a set of access vector decisions based on the
 527 * SID pair (@ssid, @tsid) for the permissions in @tclass.
 528 * Return -%EINVAL if any of the parameters are invalid or %0
 529 * if the access vector decisions were computed successfully.
 530 */
 531int security_compute_av(u32 ssid,
 532                        u32 tsid,
 533                        u16 tclass,
 534                        u32 requested,
 535                        struct av_decision *avd)
 536{
 537        struct context *scontext = NULL, *tcontext = NULL;
 538        int rc = 0;
 539
 540        if (!ss_initialized) {
 541                avd->allowed = 0xffffffff;
 542                avd->decided = 0xffffffff;
 543                avd->auditallow = 0;
 544                avd->auditdeny = 0xffffffff;
 545                avd->seqno = latest_granting;
 546                return 0;
 547        }
 548
 549        POLICY_RDLOCK;
 550
 551        scontext = sidtab_search(&sidtab, ssid);
 552        if (!scontext) {
 553                printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
 554                       ssid);
 555                rc = -EINVAL;
 556                goto out;
 557        }
 558        tcontext = sidtab_search(&sidtab, tsid);
 559        if (!tcontext) {
 560                printk(KERN_ERR "security_compute_av:  unrecognized SID %d\n",
 561                       tsid);
 562                rc = -EINVAL;
 563                goto out;
 564        }
 565
 566        rc = context_struct_compute_av(scontext, tcontext, tclass,
 567                                       requested, avd);
 568out:
 569        POLICY_RDUNLOCK;
 570        return rc;
 571}
 572
 573/*
 574 * Write the security context string representation of
 575 * the context structure `context' into a dynamically
 576 * allocated string of the correct size.  Set `*scontext'
 577 * to point to this string and set `*scontext_len' to
 578 * the length of the string.
 579 */
 580static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
 581{
 582        char *scontextp;
 583
 584        *scontext = NULL;
 585        *scontext_len = 0;
 586
 587        /* Compute the size of the context. */
 588        *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
 589        *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
 590        *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
 591        *scontext_len += mls_compute_context_len(context);
 592
 593        /* Allocate space for the context; caller must free this space. */
 594        scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
 595        if (!scontextp) {
 596                return -ENOMEM;
 597        }
 598        *scontext = scontextp;
 599
 600        /*
 601         * Copy the user name, role name and type name into the context.
 602         */
 603        sprintf(scontextp, "%s:%s:%s",
 604                policydb.p_user_val_to_name[context->user - 1],
 605                policydb.p_role_val_to_name[context->role - 1],
 606                policydb.p_type_val_to_name[context->type - 1]);
 607        scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
 608                     1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
 609                     1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
 610
 611        mls_sid_to_context(context, &scontextp);
 612
 613        *scontextp = 0;
 614
 615        return 0;
 616}
 617
 618#include "initial_sid_to_string.h"
 619
 620const char *security_get_initial_sid_context(u32 sid)
 621{
 622        if (unlikely(sid > SECINITSID_NUM))
 623                return NULL;
 624        return initial_sid_to_string[sid];
 625}
 626
 627/**
 628 * security_sid_to_context - Obtain a context for a given SID.
 629 * @sid: security identifier, SID
 630 * @scontext: security context
 631 * @scontext_len: length in bytes
 632 *
 633 * Write the string representation of the context associated with @sid
 634 * into a dynamically allocated string of the correct size.  Set @scontext
 635 * to point to this string and set @scontext_len to the length of the string.
 636 */
 637int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
 638{
 639        struct context *context;
 640        int rc = 0;
 641
 642        *scontext = NULL;
 643        *scontext_len  = 0;
 644
 645        if (!ss_initialized) {
 646                if (sid <= SECINITSID_NUM) {
 647                        char *scontextp;
 648
 649                        *scontext_len = strlen(initial_sid_to_string[sid]) + 1;
 650                        scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
 651                        if (!scontextp) {
 652                                rc = -ENOMEM;
 653                                goto out;
 654                        }
 655                        strcpy(scontextp, initial_sid_to_string[sid]);
 656                        *scontext = scontextp;
 657                        goto out;
 658                }
 659                printk(KERN_ERR "security_sid_to_context:  called before initial "
 660                       "load_policy on unknown SID %d\n", sid);
 661                rc = -EINVAL;
 662                goto out;
 663        }
 664        POLICY_RDLOCK;
 665        context = sidtab_search(&sidtab, sid);
 666        if (!context) {
 667                printk(KERN_ERR "security_sid_to_context:  unrecognized SID "
 668                       "%d\n", sid);
 669                rc = -EINVAL;
 670                goto out_unlock;
 671        }
 672        rc = context_struct_to_string(context, scontext, scontext_len);
 673out_unlock:
 674        POLICY_RDUNLOCK;
 675out:
 676        return rc;
 677
 678}
 679
 680static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
 681{
 682        char *scontext2;
 683        struct context context;
 684        struct role_datum *role;
 685        struct type_datum *typdatum;
 686        struct user_datum *usrdatum;
 687        char *scontextp, *p, oldc;
 688        int rc = 0;
 689
 690        if (!ss_initialized) {
 691                int i;
 692
 693                for (i = 1; i < SECINITSID_NUM; i++) {
 694                        if (!strcmp(initial_sid_to_string[i], scontext)) {
 695                                *sid = i;
 696                                goto out;
 697                        }
 698                }
 699                *sid = SECINITSID_KERNEL;
 700                goto out;
 701        }
 702        *sid = SECSID_NULL;
 703
 704        /* Copy the string so that we can modify the copy as we parse it.
 705           The string should already by null terminated, but we append a
 706           null suffix to the copy to avoid problems with the existing
 707           attr package, which doesn't view the null terminator as part
 708           of the attribute value. */
 709        scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
 710        if (!scontext2) {
 711                rc = -ENOMEM;
 712                goto out;
 713        }
 714        memcpy(scontext2, scontext, scontext_len);
 715        scontext2[scontext_len] = 0;
 716
 717        context_init(&context);
 718        *sid = SECSID_NULL;
 719
 720        POLICY_RDLOCK;
 721
 722        /* Parse the security context. */
 723
 724        rc = -EINVAL;
 725        scontextp = (char *) scontext2;
 726
 727        /* Extract the user. */
 728        p = scontextp;
 729        while (*p && *p != ':')
 730                p++;
 731
 732        if (*p == 0)
 733                goto out_unlock;
 734
 735        *p++ = 0;
 736
 737        usrdatum = hashtab_search(policydb.p_users.table, scontextp);
 738        if (!usrdatum)
 739                goto out_unlock;
 740
 741        context.user = usrdatum->value;
 742
 743        /* Extract role. */
 744        scontextp = p;
 745        while (*p && *p != ':')
 746                p++;
 747
 748        if (*p == 0)
 749                goto out_unlock;
 750
 751        *p++ = 0;
 752
 753        role = hashtab_search(policydb.p_roles.table, scontextp);
 754        if (!role)
 755                goto out_unlock;
 756        context.role = role->value;
 757
 758        /* Extract type. */
 759        scontextp = p;
 760        while (*p && *p != ':')
 761                p++;
 762        oldc = *p;
 763        *p++ = 0;
 764
 765        typdatum = hashtab_search(policydb.p_types.table, scontextp);
 766        if (!typdatum)
 767                goto out_unlock;
 768
 769        context.type = typdatum->value;
 770
 771        rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
 772        if (rc)
 773                goto out_unlock;
 774
 775        if ((p - scontext2) < scontext_len) {
 776                rc = -EINVAL;
 777                goto out_unlock;
 778        }
 779
 780        /* Check the validity of the new context. */
 781        if (!policydb_context_isvalid(&policydb, &context)) {
 782                rc = -EINVAL;
 783                goto out_unlock;
 784        }
 785        /* Obtain the new sid. */
 786        rc = sidtab_context_to_sid(&sidtab, &context, sid);
 787out_unlock:
 788        POLICY_RDUNLOCK;
 789        context_destroy(&context);
 790        kfree(scontext2);
 791out:
 792        return rc;
 793}
 794
 795/**
 796 * security_context_to_sid - Obtain a SID for a given security context.
 797 * @scontext: security context
 798 * @scontext_len: length in bytes
 799 * @sid: security identifier, SID
 800 *
 801 * Obtains a SID associated with the security context that
 802 * has the string representation specified by @scontext.
 803 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
 804 * memory is available, or 0 on success.
 805 */
 806int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
 807{
 808        return security_context_to_sid_core(scontext, scontext_len,
 809                                            sid, SECSID_NULL);
 810}
 811
 812/**
 813 * security_context_to_sid_default - Obtain a SID for a given security context,
 814 * falling back to specified default if needed.
 815 *
 816 * @scontext: security context
 817 * @scontext_len: length in bytes
 818 * @sid: security identifier, SID
 819 * @def_sid: default SID to assign on error
 820 *
 821 * Obtains a SID associated with the security context that
 822 * has the string representation specified by @scontext.
 823 * The default SID is passed to the MLS layer to be used to allow
 824 * kernel labeling of the MLS field if the MLS field is not present
 825 * (for upgrading to MLS without full relabel).
 826 * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
 827 * memory is available, or 0 on success.
 828 */
 829int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
 830{
 831        return security_context_to_sid_core(scontext, scontext_len,
 832                                            sid, def_sid);
 833}
 834
 835static int compute_sid_handle_invalid_context(
 836        struct context *scontext,
 837        struct context *tcontext,
 838        u16 tclass,
 839        struct context *newcontext)
 840{
 841        char *s = NULL, *t = NULL, *n = NULL;
 842        u32 slen, tlen, nlen;
 843
 844        if (context_struct_to_string(scontext, &s, &slen) < 0)
 845                goto out;
 846        if (context_struct_to_string(tcontext, &t, &tlen) < 0)
 847                goto out;
 848        if (context_struct_to_string(newcontext, &n, &nlen) < 0)
 849                goto out;
 850        audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
 851                  "security_compute_sid:  invalid context %s"
 852                  " for scontext=%s"
 853                  " tcontext=%s"
 854                  " tclass=%s",
 855                  n, s, t, policydb.p_class_val_to_name[tclass-1]);
 856out:
 857        kfree(s);
 858        kfree(t);
 859        kfree(n);
 860        if (!selinux_enforcing)
 861                return 0;
 862        return -EACCES;
 863}
 864
 865static int security_compute_sid(u32 ssid,
 866                                u32 tsid,
 867                                u16 tclass,
 868                                u32 specified,
 869                                u32 *out_sid)
 870{
 871        struct context *scontext = NULL, *tcontext = NULL, newcontext;
 872        struct role_trans *roletr = NULL;
 873        struct avtab_key avkey;
 874        struct avtab_datum *avdatum;
 875        struct avtab_node *node;
 876        int rc = 0;
 877
 878        if (!ss_initialized) {
 879                switch (tclass) {
 880                case SECCLASS_PROCESS:
 881                        *out_sid = ssid;
 882                        break;
 883                default:
 884                        *out_sid = tsid;
 885                        break;
 886                }
 887                goto out;
 888        }
 889
 890        context_init(&newcontext);
 891
 892        POLICY_RDLOCK;
 893
 894        scontext = sidtab_search(&sidtab, ssid);
 895        if (!scontext) {
 896                printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
 897                       ssid);
 898                rc = -EINVAL;
 899                goto out_unlock;
 900        }
 901        tcontext = sidtab_search(&sidtab, tsid);
 902        if (!tcontext) {
 903                printk(KERN_ERR "security_compute_sid:  unrecognized SID %d\n",
 904                       tsid);
 905                rc = -EINVAL;
 906                goto out_unlock;
 907        }
 908
 909        /* Set the user identity. */
 910        switch (specified) {
 911        case AVTAB_TRANSITION:
 912        case AVTAB_CHANGE:
 913                /* Use the process user identity. */
 914                newcontext.user = scontext->user;
 915                break;
 916        case AVTAB_MEMBER:
 917                /* Use the related object owner. */
 918                newcontext.user = tcontext->user;
 919                break;
 920        }
 921
 922        /* Set the role and type to default values. */
 923        switch (tclass) {
 924        case SECCLASS_PROCESS:
 925                /* Use the current role and type of process. */
 926                newcontext.role = scontext->role;
 927                newcontext.type = scontext->type;
 928                break;
 929        default:
 930                /* Use the well-defined object role. */
 931                newcontext.role = OBJECT_R_VAL;
 932                /* Use the type of the related object. */
 933                newcontext.type = tcontext->type;
 934        }
 935
 936        /* Look for a type transition/member/change rule. */
 937        avkey.source_type = scontext->type;
 938        avkey.target_type = tcontext->type;
 939        avkey.target_class = tclass;
 940        avkey.specified = specified;
 941        avdatum = avtab_search(&policydb.te_avtab, &avkey);
 942
 943        /* If no permanent rule, also check for enabled conditional rules */
 944        if(!avdatum) {
 945                node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
 946                for (; node != NULL; node = avtab_search_node_next(node, specified)) {
 947                        if (node->key.specified & AVTAB_ENABLED) {
 948                                avdatum = &node->datum;
 949                                break;
 950                        }
 951                }
 952        }
 953
 954        if (avdatum) {
 955                /* Use the type from the type transition/member/change rule. */
 956                newcontext.type = avdatum->data;
 957        }
 958
 959        /* Check for class-specific changes. */
 960        switch (tclass) {
 961        case SECCLASS_PROCESS:
 962                if (specified & AVTAB_TRANSITION) {
 963                        /* Look for a role transition rule. */
 964                        for (roletr = policydb.role_tr; roletr;
 965                             roletr = roletr->next) {
 966                                if (roletr->role == scontext->role &&
 967                                    roletr->type == tcontext->type) {
 968                                        /* Use the role transition rule. */
 969                                        newcontext.role = roletr->new_role;
 970                                        break;
 971                                }
 972                        }
 973                }
 974                break;
 975        default:
 976                break;
 977        }
 978
 979        /* Set the MLS attributes.
 980           This is done last because it may allocate memory. */
 981        rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
 982        if (rc)
 983                goto out_unlock;
 984
 985        /* Check the validity of the context. */
 986        if (!policydb_context_isvalid(&policydb, &newcontext)) {
 987                rc = compute_sid_handle_invalid_context(scontext,
 988                                                        tcontext,
 989                                                        tclass,
 990                                                        &newcontext);
 991                if (rc)
 992                        goto out_unlock;
 993        }
 994        /* Obtain the sid for the context. */
 995        rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
 996out_unlock:
 997        POLICY_RDUNLOCK;
 998        context_destroy(&newcontext);
 999out:
1000        return rc;
1001}
1002
1003/**
1004 * security_transition_sid - Compute the SID for a new subject/object.
1005 * @ssid: source security identifier
1006 * @tsid: target security identifier
1007 * @tclass: target security class
1008 * @out_sid: security identifier for new subject/object
1009 *
1010 * Compute a SID to use for labeling a new subject or object in the
1011 * class @tclass based on a SID pair (@ssid, @tsid).
1012 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1013 * if insufficient memory is available, or %0 if the new SID was
1014 * computed successfully.
1015 */
1016int security_transition_sid(u32 ssid,
1017                            u32 tsid,
1018                            u16 tclass,
1019                            u32 *out_sid)
1020{
1021        return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
1022}
1023
1024/**
1025 * security_member_sid - Compute the SID for member selection.
1026 * @ssid: source security identifier
1027 * @tsid: target security identifier
1028 * @tclass: target security class
1029 * @out_sid: security identifier for selected member
1030 *
1031 * Compute a SID to use when selecting a member of a polyinstantiated
1032 * object of class @tclass based on a SID pair (@ssid, @tsid).
1033 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1034 * if insufficient memory is available, or %0 if the SID was
1035 * computed successfully.
1036 */
1037int security_member_sid(u32 ssid,
1038                        u32 tsid,
1039                        u16 tclass,
1040                        u32 *out_sid)
1041{
1042        return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
1043}
1044
1045/**
1046 * security_change_sid - Compute the SID for object relabeling.
1047 * @ssid: source security identifier
1048 * @tsid: target security identifier
1049 * @tclass: target security class
1050 * @out_sid: security identifier for selected member
1051 *
1052 * Compute a SID to use for relabeling an object of class @tclass
1053 * based on a SID pair (@ssid, @tsid).
1054 * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
1055 * if insufficient memory is available, or %0 if the SID was
1056 * computed successfully.
1057 */
1058int security_change_sid(u32 ssid,
1059                        u32 tsid,
1060                        u16 tclass,
1061                        u32 *out_sid)
1062{
1063        return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
1064}
1065
1066/*
1067 * Verify that each kernel class that is defined in the
1068 * policy is correct
1069 */
1070static int validate_classes(struct policydb *p)
1071{
1072        int i, j;
1073        struct class_datum *cladatum;
1074        struct perm_datum *perdatum;
1075        u32 nprim, tmp, common_pts_len, perm_val, pol_val;
1076        u16 class_val;
1077        const struct selinux_class_perm *kdefs = &selinux_class_perm;
1078        const char *def_class, *def_perm, *pol_class;
1079        struct symtab *perms;
1080
1081        if (p->allow_unknown) {
1082                u32 num_classes = kdefs->cts_len;
1083                p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
1084                if (!p->undefined_perms)
1085                        return -ENOMEM;
1086        }
1087
1088        for (i = 1; i < kdefs->cts_len; i++) {
1089                def_class = kdefs->class_to_string[i];
1090                if (!def_class)
1091                        continue;
1092                if (i > p->p_classes.nprim) {
1093                        printk(KERN_INFO
1094                               "security:  class %s not defined in policy\n",
1095                               def_class);
1096                        if (p->reject_unknown)
1097                                return -EINVAL;
1098                        if (p->allow_unknown)
1099                                p->undefined_perms[i-1] = ~0U;
1100                        continue;
1101                }
1102                pol_class = p->p_class_val_to_name[i-1];
1103                if (strcmp(pol_class, def_class)) {
1104                        printk(KERN_ERR
1105                               "security:  class %d is incorrect, found %s but should be %s\n",
1106                               i, pol_class, def_class);
1107                        return -EINVAL;
1108                }
1109        }
1110        for (i = 0; i < kdefs->av_pts_len; i++) {
1111                class_val = kdefs->av_perm_to_string[i].tclass;
1112                perm_val = kdefs->av_perm_to_string[i].value;
1113                def_perm = kdefs->av_perm_to_string[i].name;
1114                if (class_val > p->p_classes.nprim)
1115                        continue;
1116                pol_class = p->p_class_val_to_name[class_val-1];
1117                cladatum = hashtab_search(p->p_classes.table, pol_class);
1118                BUG_ON(!cladatum);
1119                perms = &cladatum->permissions;
1120                nprim = 1 << (perms->nprim - 1);
1121                if (perm_val > nprim) {
1122                        printk(KERN_INFO
1123                               "security:  permission %s in class %s not defined in policy\n",
1124                               def_perm, pol_class);
1125                        if (p->reject_unknown)
1126                                return -EINVAL;
1127                        if (p->allow_unknown)
1128                                p->undefined_perms[class_val-1] |= perm_val;
1129                        continue;
1130                }
1131                perdatum = hashtab_search(perms->table, def_perm);
1132                if (perdatum == NULL) {
1133                        printk(KERN_ERR
1134                               "security:  permission %s in class %s not found in policy, bad policy\n",
1135                               def_perm, pol_class);
1136                        return -EINVAL;
1137                }
1138                pol_val = 1 << (perdatum->value - 1);
1139                if (pol_val != perm_val) {
1140                        printk(KERN_ERR
1141                               "security:  permission %s in class %s has incorrect value\n",
1142                               def_perm, pol_class);
1143                        return -EINVAL;
1144                }
1145        }
1146        for (i = 0; i < kdefs->av_inherit_len; i++) {
1147                class_val = kdefs->av_inherit[i].tclass;
1148                if (class_val > p->p_classes.nprim)
1149                        continue;
1150                pol_class = p->p_class_val_to_name[class_val-1];
1151                cladatum = hashtab_search(p->p_classes.table, pol_class);
1152                BUG_ON(!cladatum);
1153                if (!cladatum->comdatum) {
1154                        printk(KERN_ERR
1155                               "security:  class %s should have an inherits clause but does not\n",
1156                               pol_class);
1157                        return -EINVAL;
1158                }
1159                tmp = kdefs->av_inherit[i].common_base;
1160                common_pts_len = 0;
1161                while (!(tmp & 0x01)) {
1162                        common_pts_len++;
1163                        tmp >>= 1;
1164                }
1165                perms = &cladatum->comdatum->permissions;
1166                for (j = 0; j < common_pts_len; j++) {
1167                        def_perm = kdefs->av_inherit[i].common_pts[j];
1168                        if (j >= perms->nprim) {
1169                                printk(KERN_INFO
1170                                       "security:  permission %s in class %s not defined in policy\n",
1171                                       def_perm, pol_class);
1172                                if (p->reject_unknown)
1173                                        return -EINVAL;
1174                                if (p->allow_unknown)
1175                                        p->undefined_perms[class_val-1] |= (1 << j);
1176                                continue;
1177                        }
1178                        perdatum = hashtab_search(perms->table, def_perm);
1179                        if (perdatum == NULL) {
1180                                printk(KERN_ERR
1181                                       "security:  permission %s in class %s not found in policy, bad policy\n",
1182                                       def_perm, pol_class);
1183                                return -EINVAL;
1184                        }
1185                        if (perdatum->value != j + 1) {
1186                                printk(KERN_ERR
1187                                       "security:  permission %s in class %s has incorrect value\n",
1188                                       def_perm, pol_class);
1189                                return -EINVAL;
1190                        }
1191                }
1192        }
1193        return 0;
1194}
1195
1196/* Clone the SID into the new SID table. */
1197static int clone_sid(u32 sid,
1198                     struct context *context,
1199                     void *arg)
1200{
1201        struct sidtab *s = arg;
1202
1203        return sidtab_insert(s, sid, context);
1204}
1205
1206static inline int convert_context_handle_invalid_context(struct context *context)
1207{
1208        int rc = 0;
1209
1210        if (selinux_enforcing) {
1211                rc = -EINVAL;
1212        } else {
1213                char *s;
1214                u32 len;
1215
1216                context_struct_to_string(context, &s, &len);
1217                printk(KERN_ERR "security:  context %s is invalid\n", s);
1218                kfree(s);
1219        }
1220        return rc;
1221}
1222
1223struct convert_context_args {
1224        struct policydb *oldp;
1225        struct policydb *newp;
1226};
1227
1228/*
1229 * Convert the values in the security context
1230 * structure `c' from the values specified
1231 * in the policy `p->oldp' to the values specified
1232 * in the policy `p->newp'.  Verify that the
1233 * context is valid under the new policy.
1234 */
1235static int convert_context(u32 key,
1236                           struct context *c,
1237                           void *p)
1238{
1239        struct convert_context_args *args;
1240        struct context oldc;
1241        struct role_datum *role;
1242        struct type_datum *typdatum;
1243        struct user_datum *usrdatum;
1244        char *s;
1245        u32 len;
1246        int rc;
1247
1248        args = p;
1249
1250        rc = context_cpy(&oldc, c);
1251        if (rc)
1252                goto out;
1253
1254        rc = -EINVAL;
1255
1256        /* Convert the user. */
1257        usrdatum = hashtab_search(args->newp->p_users.table,
1258                                  args->oldp->p_user_val_to_name[c->user - 1]);
1259        if (!usrdatum) {
1260                goto bad;
1261        }
1262        c->user = usrdatum->value;
1263
1264        /* Convert the role. */
1265        role = hashtab_search(args->newp->p_roles.table,
1266                              args->oldp->p_role_val_to_name[c->role - 1]);
1267        if (!role) {
1268                goto bad;
1269        }
1270        c->role = role->value;
1271
1272        /* Convert the type. */
1273        typdatum = hashtab_search(args->newp->p_types.table,
1274                                  args->oldp->p_type_val_to_name[c->type - 1]);
1275        if (!typdatum) {
1276                goto bad;
1277        }
1278        c->type = typdatum->value;
1279
1280        rc = mls_convert_context(args->oldp, args->newp, c);
1281        if (rc)
1282                goto bad;
1283
1284        /* Check the validity of the new context. */
1285        if (!policydb_context_isvalid(args->newp, c)) {
1286                rc = convert_context_handle_invalid_context(&oldc);
1287                if (rc)
1288                        goto bad;
1289        }
1290
1291        context_destroy(&oldc);
1292out:
1293        return rc;
1294bad:
1295        context_struct_to_string(&oldc, &s, &len);
1296        context_destroy(&oldc);
1297        printk(KERN_ERR "security:  invalidating context %s\n", s);
1298        kfree(s);
1299        goto out;
1300}
1301
1302extern void selinux_complete_init(void);
1303static int security_preserve_bools(struct policydb *p);
1304
1305/**
1306 * security_load_policy - Load a security policy configuration.
1307 * @data: binary policy data
1308 * @len: length of data in bytes
1309 *
1310 * Load a new set of security policy configuration data,
1311 * validate it and convert the SID table as necessary.
1312 * This function will flush the access vector cache after
1313 * loading the new policy.
1314 */
1315int security_load_policy(void *data, size_t len)
1316{
1317        struct policydb oldpolicydb, newpolicydb;
1318        struct sidtab oldsidtab, newsidtab;
1319        struct convert_context_args args;
1320        u32 seqno;
1321        int rc = 0;
1322        struct policy_file file = { data, len }, *fp = &file;
1323
1324        LOAD_LOCK;
1325
1326        if (!ss_initialized) {
1327                avtab_cache_init();
1328                if (policydb_read(&policydb, fp)) {
1329                        LOAD_UNLOCK;
1330                        avtab_cache_destroy();
1331                        return -EINVAL;
1332                }
1333                if (policydb_load_isids(&policydb, &sidtab)) {
1334                        LOAD_UNLOCK;
1335                        policydb_destroy(&policydb);
1336                        avtab_cache_destroy();
1337                        return -EINVAL;
1338                }
1339                /* Verify that the kernel defined classes are correct. */
1340                if (validate_classes(&policydb)) {
1341                        printk(KERN_ERR
1342                               "security:  the definition of a class is incorrect\n");
1343                        LOAD_UNLOCK;
1344                        sidtab_destroy(&sidtab);
1345                        policydb_destroy(&policydb);
1346                        avtab_cache_destroy();
1347                        return -EINVAL;
1348                }
1349                policydb_loaded_version = policydb.policyvers;
1350                ss_initialized = 1;
1351                seqno = ++latest_granting;
1352                LOAD_UNLOCK;
1353                selinux_complete_init();
1354                avc_ss_reset(seqno);
1355                selnl_notify_policyload(seqno);
1356                selinux_netlbl_cache_invalidate();
1357                selinux_xfrm_notify_policyload();
1358                return 0;
1359        }
1360
1361#if 0
1362        sidtab_hash_eval(&sidtab, "sids");
1363#endif
1364
1365        if (policydb_read(&newpolicydb, fp)) {
1366                LOAD_UNLOCK;
1367                return -EINVAL;
1368        }
1369
1370        sidtab_init(&newsidtab);
1371
1372        /* Verify that the kernel defined classes are correct. */
1373        if (validate_classes(&newpolicydb)) {
1374                printk(KERN_ERR
1375                       "security:  the definition of a class is incorrect\n");
1376                rc = -EINVAL;
1377                goto err;
1378        }
1379
1380        rc = security_preserve_bools(&newpolicydb);
1381        if (rc) {
1382                printk(KERN_ERR "security:  unable to preserve booleans\n");
1383                goto err;
1384        }
1385
1386        /* Clone the SID table. */
1387        sidtab_shutdown(&sidtab);
1388        if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
1389                rc = -ENOMEM;
1390                goto err;
1391        }
1392
1393        /* Convert the internal representations of contexts
1394           in the new SID table and remove invalid SIDs. */
1395        args.oldp = &policydb;
1396        args.newp = &newpolicydb;
1397        sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
1398
1399        /* Save the old policydb and SID table to free later. */
1400        memcpy(&oldpolicydb, &policydb, sizeof policydb);
1401        sidtab_set(&oldsidtab, &sidtab);
1402
1403        /* Install the new policydb and SID table. */
1404        POLICY_WRLOCK;
1405        memcpy(&policydb, &newpolicydb, sizeof policydb);
1406        sidtab_set(&sidtab, &newsidtab);
1407        seqno = ++latest_granting;
1408        policydb_loaded_version = policydb.policyvers;
1409        POLICY_WRUNLOCK;
1410        LOAD_UNLOCK;
1411
1412        /* Free the old policydb and SID table. */
1413        policydb_destroy(&oldpolicydb);
1414        sidtab_destroy(&oldsidtab);
1415
1416        avc_ss_reset(seqno);
1417        selnl_notify_policyload(seqno);
1418        selinux_netlbl_cache_invalidate();
1419        selinux_xfrm_notify_policyload();
1420
1421        return 0;
1422
1423err:
1424        LOAD_UNLOCK;
1425        sidtab_destroy(&newsidtab);
1426        policydb_destroy(&newpolicydb);
1427        return rc;
1428
1429}
1430
1431/**
1432 * security_port_sid - Obtain the SID for a port.
1433 * @domain: communication domain aka address family
1434 * @type: socket type
1435 * @protocol: protocol number
1436 * @port: port number
1437 * @out_sid: security identifier
1438 */
1439int security_port_sid(u16 domain,
1440                      u16 type,
1441                      u8 protocol,
1442                      u16 port,
1443                      u32 *out_sid)
1444{
1445        struct ocontext *c;
1446        int rc = 0;
1447
1448        POLICY_RDLOCK;
1449
1450        c = policydb.ocontexts[OCON_PORT];
1451        while (c) {
1452                if (c->u.port.protocol == protocol &&
1453                    c->u.port.low_port <= port &&
1454                    c->u.port.high_port >= port)
1455                        break;
1456                c = c->next;
1457        }
1458
1459        if (c) {
1460                if (!c->sid[0]) {
1461                        rc = sidtab_context_to_sid(&sidtab,
1462                                                   &c->context[0],
1463                                                   &c->sid[0]);
1464                        if (rc)
1465                                goto out;
1466                }
1467                *out_sid = c->sid[0];
1468        } else {
1469                *out_sid = SECINITSID_PORT;
1470        }
1471
1472out:
1473        POLICY_RDUNLOCK;
1474        return rc;
1475}
1476
1477/**
1478 * security_netif_sid - Obtain the SID for a network interface.
1479 * @name: interface name
1480 * @if_sid: interface SID
1481 * @msg_sid: default SID for received packets
1482 */
1483int security_netif_sid(char *name,
1484                       u32 *if_sid,
1485                       u32 *msg_sid)
1486{
1487        int rc = 0;
1488        struct ocontext *c;
1489
1490        POLICY_RDLOCK;
1491
1492        c = policydb.ocontexts[OCON_NETIF];
1493        while (c) {
1494                if (strcmp(name, c->u.name) == 0)
1495                        break;
1496                c = c->next;
1497        }
1498
1499        if (c) {
1500                if (!c->sid[0] || !c->sid[1]) {
1501                        rc = sidtab_context_to_sid(&sidtab,
1502                                                  &c->context[0],
1503                                                  &c->sid[0]);
1504                        if (rc)
1505                                goto out;
1506                        rc = sidtab_context_to_sid(&sidtab,
1507                                                   &c->context[1],
1508                                                   &c->sid[1]);
1509                        if (rc)
1510                                goto out;
1511                }
1512                *if_sid = c->sid[0];
1513                *msg_sid = c->sid[1];
1514        } else {
1515                *if_sid = SECINITSID_NETIF;
1516                *msg_sid = SECINITSID_NETMSG;
1517        }
1518
1519out:
1520        POLICY_RDUNLOCK;
1521        return rc;
1522}
1523
1524static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
1525{
1526        int i, fail = 0;
1527
1528        for(i = 0; i < 4; i++)
1529                if(addr[i] != (input[i] & mask[i])) {
1530                        fail = 1;
1531                        break;
1532                }
1533
1534        return !fail;
1535}
1536
1537/**
1538 * security_node_sid - Obtain the SID for a node (host).
1539 * @domain: communication domain aka address family
1540 * @addrp: address
1541 * @addrlen: address length in bytes
1542 * @out_sid: security identifier
1543 */
1544int security_node_sid(u16 domain,
1545                      void *addrp,
1546                      u32 addrlen,
1547                      u32 *out_sid)
1548{
1549        int rc = 0;
1550        struct ocontext *c;
1551
1552        POLICY_RDLOCK;
1553
1554        switch (domain) {
1555        case AF_INET: {
1556                u32 addr;
1557
1558                if (addrlen != sizeof(u32)) {
1559                        rc = -EINVAL;
1560                        goto out;
1561                }
1562
1563                addr = *((u32 *)addrp);
1564
1565                c = policydb.ocontexts[OCON_NODE];
1566                while (c) {
1567                        if (c->u.node.addr == (addr & c->u.node.mask))
1568                                break;
1569                        c = c->next;
1570                }
1571                break;
1572        }
1573
1574        case AF_INET6:
1575                if (addrlen != sizeof(u64) * 2) {
1576                        rc = -EINVAL;
1577                        goto out;
1578                }
1579                c = policydb.ocontexts[OCON_NODE6];
1580                while (c) {
1581                        if (match_ipv6_addrmask(addrp, c->u.node6.addr,
1582                                                c->u.node6.mask))
1583                                break;
1584                        c = c->next;
1585                }
1586                break;
1587
1588        default:
1589                *out_sid = SECINITSID_NODE;
1590                goto out;
1591        }
1592
1593        if (c) {
1594                if (!c->sid[0]) {
1595                        rc = sidtab_context_to_sid(&sidtab,
1596                                                   &c->context[0],
1597                                                   &c->sid[0]);
1598                        if (rc)
1599                                goto out;
1600                }
1601                *out_sid = c->sid[0];
1602        } else {
1603                *out_sid = SECINITSID_NODE;
1604        }
1605
1606out:
1607        POLICY_RDUNLOCK;
1608        return rc;
1609}
1610
1611#define SIDS_NEL 25
1612
1613/**
1614 * security_get_user_sids - Obtain reachable SIDs for a user.
1615 * @fromsid: starting SID
1616 * @username: username
1617 * @sids: array of reachable SIDs for user
1618 * @nel: number of elements in @sids
1619 *
1620 * Generate the set of SIDs for legal security contexts
1621 * for a given user that can be reached by @fromsid.
1622 * Set *@sids to point to a dynamically allocated
1623 * array containing the set of SIDs.  Set *@nel to the
1624 * number of elements in the array.
1625 */
1626
1627int security_get_user_sids(u32 fromsid,
1628                           char *username,
1629                           u32 **sids,
1630                           u32 *nel)
1631{
1632        struct context *fromcon, usercon;
1633        u32 *mysids = NULL, *mysids2, sid;
1634        u32 mynel = 0, maxnel = SIDS_NEL;
1635        struct user_datum *user;
1636        struct role_datum *role;
1637        struct ebitmap_node *rnode, *tnode;
1638        int rc = 0, i, j;
1639
1640        *sids = NULL;
1641        *nel = 0;
1642
1643        if (!ss_initialized)
1644                goto out;
1645
1646        POLICY_RDLOCK;
1647
1648        fromcon = sidtab_search(&sidtab, fromsid);
1649        if (!fromcon) {
1650                rc = -EINVAL;
1651                goto out_unlock;
1652        }
1653
1654        user = hashtab_search(policydb.p_users.table, username);
1655        if (!user) {
1656                rc = -EINVAL;
1657                goto out_unlock;
1658        }
1659        usercon.user = user->value;
1660
1661        mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
1662        if (!mysids) {
1663                rc = -ENOMEM;
1664                goto out_unlock;
1665        }
1666
1667        ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
1668                role = policydb.role_val_to_struct[i];
1669                usercon.role = i+1;
1670                ebitmap_for_each_positive_bit(&role->types, tnode, j) {
1671                        usercon.type = j+1;
1672
1673                        if (mls_setup_user_range(fromcon, user, &usercon))
1674                                continue;
1675
1676                        rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
1677                        if (rc)
1678                                goto out_unlock;
1679                        if (mynel < maxnel) {
1680                                mysids[mynel++] = sid;
1681                        } else {
1682                                maxnel += SIDS_NEL;
1683                                mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
1684                                if (!mysids2) {
1685                                        rc = -ENOMEM;
1686                                        goto out_unlock;
1687                                }
1688                                memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
1689                                kfree(mysids);
1690                                mysids = mysids2;
1691                                mysids[mynel++] = sid;
1692                        }
1693                }
1694        }
1695
1696out_unlock:
1697        POLICY_RDUNLOCK;
1698        if (rc || !mynel) {
1699                kfree(mysids);
1700                goto out;
1701        }
1702
1703        mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
1704        if (!mysids2) {
1705                rc = -ENOMEM;
1706                kfree(mysids);
1707                goto out;
1708        }
1709        for (i = 0, j = 0; i < mynel; i++) {
1710                rc = avc_has_perm_noaudit(fromsid, mysids[i],
1711                                          SECCLASS_PROCESS,
1712                                          PROCESS__TRANSITION, AVC_STRICT,
1713                                          NULL);
1714                if (!rc)
1715                        mysids2[j++] = mysids[i];
1716                cond_resched();
1717        }
1718        rc = 0;
1719        kfree(mysids);
1720        *sids = mysids2;
1721        *nel = j;
1722out:
1723        return rc;
1724}
1725
1726/**
1727 * security_genfs_sid - Obtain a SID for a file in a filesystem
1728 * @fstype: filesystem type
1729 * @path: path from root of mount
1730 * @sclass: file security class
1731 * @sid: SID for path
1732 *
1733 * Obtain a SID to use for a file in a filesystem that
1734 * cannot support xattr or use a fixed labeling behavior like
1735 * transition SIDs or task SIDs.
1736 */
1737int security_genfs_sid(const char *fstype,
1738                       char *path,
1739                       u16 sclass,
1740                       u32 *sid)
1741{
1742        int len;
1743        struct genfs *genfs;
1744        struct ocontext *c;
1745        int rc = 0, cmp = 0;
1746
1747        POLICY_RDLOCK;
1748
1749        for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
1750                cmp = strcmp(fstype, genfs->fstype);
1751                if (cmp <= 0)
1752                        break;
1753        }
1754
1755        if (!genfs || cmp) {
1756                *sid = SECINITSID_UNLABELED;
1757                rc = -ENOENT;
1758                goto out;
1759        }
1760
1761        for (c = genfs->head; c; c = c->next) {
1762                len = strlen(c->u.name);
1763                if ((!c->v.sclass || sclass == c->v.sclass) &&
1764                    (strncmp(c->u.name, path, len) == 0))
1765                        break;
1766        }
1767
1768        if (!c) {
1769                *sid = SECINITSID_UNLABELED;
1770                rc = -ENOENT;
1771                goto out;
1772        }
1773
1774        if (!c->sid[0]) {
1775                rc = sidtab_context_to_sid(&sidtab,
1776                                           &c->context[0],
1777                                           &c->sid[0]);
1778                if (rc)
1779                        goto out;
1780        }
1781
1782        *sid = c->sid[0];
1783out:
1784        POLICY_RDUNLOCK;
1785        return rc;
1786}
1787
1788/**
1789 * security_fs_use - Determine how to handle labeling for a filesystem.
1790 * @fstype: filesystem type
1791 * @behavior: labeling behavior
1792 * @sid: SID for filesystem (superblock)
1793 */
1794int security_fs_use(
1795        const char *fstype,
1796        unsigned int *behavior,
1797        u32 *sid)
1798{
1799        int rc = 0;
1800        struct ocontext *c;
1801
1802        POLICY_RDLOCK;
1803
1804        c = policydb.ocontexts[OCON_FSUSE];
1805        while (c) {
1806                if (strcmp(fstype, c->u.name) == 0)
1807                        break;
1808                c = c->next;
1809        }
1810
1811        if (c) {
1812                *behavior = c->v.behavior;
1813                if (!c->sid[0]) {
1814                        rc = sidtab_context_to_sid(&sidtab,
1815                                                   &c->context[0],
1816                                                   &c->sid[0]);
1817                        if (rc)
1818                                goto out;
1819                }
1820                *sid = c->sid[0];
1821        } else {
1822                rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
1823                if (rc) {
1824                        *behavior = SECURITY_FS_USE_NONE;
1825                        rc = 0;
1826                } else {
1827                        *behavior = SECURITY_FS_USE_GENFS;
1828                }
1829        }
1830
1831out:
1832        POLICY_RDUNLOCK;
1833        return rc;
1834}
1835
1836int security_get_bools(int *len, char ***names, int **values)
1837{
1838        int i, rc = -ENOMEM;
1839
1840        POLICY_RDLOCK;
1841        *names = NULL;
1842        *values = NULL;
1843
1844        *len = policydb.p_bools.nprim;
1845        if (!*len) {
1846                rc = 0;
1847                goto out;
1848        }
1849
1850       *names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
1851        if (!*names)
1852                goto err;
1853
1854       *values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
1855        if (!*values)
1856                goto err;
1857
1858        for (i = 0; i < *len; i++) {
1859                size_t name_len;
1860                (*values)[i] = policydb.bool_val_to_struct[i]->state;
1861                name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
1862               (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
1863                if (!(*names)[i])
1864                        goto err;
1865                strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
1866                (*names)[i][name_len - 1] = 0;
1867        }
1868        rc = 0;
1869out:
1870        POLICY_RDUNLOCK;
1871        return rc;
1872err:
1873        if (*names) {
1874                for (i = 0; i < *len; i++)
1875                        kfree((*names)[i]);
1876        }
1877        kfree(*values);
1878        goto out;
1879}
1880
1881
1882int security_set_bools(int len, int *values)
1883{
1884        int i, rc = 0;
1885        int lenp, seqno = 0;
1886        struct cond_node *cur;
1887
1888        POLICY_WRLOCK;
1889
1890        lenp = policydb.p_bools.nprim;
1891        if (len != lenp) {
1892                rc = -EFAULT;
1893                goto out;
1894        }
1895
1896        for (i = 0; i < len; i++) {
1897                if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
1898                        audit_log(current->audit_context, GFP_ATOMIC,
1899                                AUDIT_MAC_CONFIG_CHANGE,
1900                                "bool=%s val=%d old_val=%d auid=%u",
1901                                policydb.p_bool_val_to_name[i],
1902                                !!values[i],
1903                                policydb.bool_val_to_struct[i]->state,
1904                                audit_get_loginuid(current->audit_context));
1905                }
1906                if (values[i]) {
1907                        policydb.bool_val_to_struct[i]->state = 1;
1908                } else {
1909                        policydb.bool_val_to_struct[i]->state = 0;
1910                }
1911        }
1912
1913        for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
1914                rc = evaluate_cond_node(&policydb, cur);
1915                if (rc)
1916                        goto out;
1917        }
1918
1919        seqno = ++latest_granting;
1920
1921out:
1922        POLICY_WRUNLOCK;
1923        if (!rc) {
1924                avc_ss_reset(seqno);
1925                selnl_notify_policyload(seqno);
1926                selinux_xfrm_notify_policyload();
1927        }
1928        return rc;
1929}
1930
1931int security_get_bool_value(int bool)
1932{
1933        int rc = 0;
1934        int len;
1935
1936        POLICY_RDLOCK;
1937
1938        len = policydb.p_bools.nprim;
1939        if (bool >= len) {
1940                rc = -EFAULT;
1941                goto out;
1942        }
1943
1944        rc = policydb.bool_val_to_struct[bool]->state;
1945out:
1946        POLICY_RDUNLOCK;
1947        return rc;
1948}
1949
1950static int security_preserve_bools(struct policydb *p)
1951{
1952        int rc, nbools = 0, *bvalues = NULL, i;
1953        char **bnames = NULL;
1954        struct cond_bool_datum *booldatum;
1955        struct cond_node *cur;
1956
1957        rc = security_get_bools(&nbools, &bnames, &bvalues);
1958        if (rc)
1959                goto out;
1960        for (i = 0; i < nbools; i++) {
1961                booldatum = hashtab_search(p->p_bools.table, bnames[i]);
1962                if (booldatum)
1963                        booldatum->state = bvalues[i];
1964        }
1965        for (cur = p->cond_list; cur != NULL; cur = cur->next) {
1966                rc = evaluate_cond_node(p, cur);
1967                if (rc)
1968                        goto out;
1969        }
1970
1971out:
1972        if (bnames) {
1973                for (i = 0; i < nbools; i++)
1974                        kfree(bnames[i]);
1975        }
1976        kfree(bnames);
1977        kfree(bvalues);
1978        return rc;
1979}
1980
1981/*
1982 * security_sid_mls_copy() - computes a new sid based on the given
1983 * sid and the mls portion of mls_sid.
1984 */
1985int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
1986{
1987        struct context *context1;
1988        struct context *context2;
1989        struct context newcon;
1990        char *s;
1991        u32 len;
1992        int rc = 0;
1993
1994        if (!ss_initialized || !selinux_mls_enabled) {
1995                *new_sid = sid;
1996                goto out;
1997        }
1998
1999        context_init(&newcon);
2000
2001        POLICY_RDLOCK;
2002        context1 = sidtab_search(&sidtab, sid);
2003        if (!context1) {
2004                printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
2005                       "%d\n", sid);
2006                rc = -EINVAL;
2007                goto out_unlock;
2008        }
2009
2010        context2 = sidtab_search(&sidtab, mls_sid);
2011        if (!context2) {
2012                printk(KERN_ERR "security_sid_mls_copy:  unrecognized SID "
2013                       "%d\n", mls_sid);
2014                rc = -EINVAL;
2015                goto out_unlock;
2016        }
2017
2018        newcon.user = context1->user;
2019        newcon.role = context1->role;
2020        newcon.type = context1->type;
2021        rc = mls_context_cpy(&newcon, context2);
2022        if (rc)
2023                goto out_unlock;
2024
2025        /* Check the validity of the new context. */
2026        if (!policydb_context_isvalid(&policydb, &newcon)) {
2027                rc = convert_context_handle_invalid_context(&newcon);
2028                if (rc)
2029                        goto bad;
2030        }
2031
2032        rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid);
2033        goto out_unlock;
2034
2035bad:
2036        if (!context_struct_to_string(&newcon, &s, &len)) {
2037                audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2038                          "security_sid_mls_copy: invalid context %s", s);
2039                kfree(s);
2040        }
2041
2042out_unlock:
2043        POLICY_RDUNLOCK;
2044        context_destroy(&newcon);
2045out:
2046        return rc;
2047}
2048
2049static int get_classes_callback(void *k, void *d, void *args)
2050{
2051        struct class_datum *datum = d;
2052        char *name = k, **classes = args;
2053        int value = datum->value - 1;
2054
2055        classes[value] = kstrdup(name, GFP_ATOMIC);
2056        if (!classes[value])
2057                return -ENOMEM;
2058
2059        return 0;
2060}
2061
2062int security_get_classes(char ***classes, int *nclasses)
2063{
2064        int rc = -ENOMEM;
2065
2066        POLICY_RDLOCK;
2067
2068        *nclasses = policydb.p_classes.nprim;
2069        *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
2070        if (!*classes)
2071                goto out;
2072
2073        rc = hashtab_map(policydb.p_classes.table, get_classes_callback,
2074                        *classes);
2075        if (rc < 0) {
2076                int i;
2077                for (i = 0; i < *nclasses; i++)
2078                        kfree((*classes)[i]);
2079                kfree(*classes);
2080        }
2081
2082out:
2083        POLICY_RDUNLOCK;
2084        return rc;
2085}
2086
2087static int get_permissions_callback(void *k, void *d, void *args)
2088{
2089        struct perm_datum *datum = d;
2090        char *name = k, **perms = args;
2091        int value = datum->value - 1;
2092
2093        perms[value] = kstrdup(name, GFP_ATOMIC);
2094        if (!perms[value])
2095                return -ENOMEM;
2096
2097        return 0;
2098}
2099
2100int security_get_permissions(char *class, char ***perms, int *nperms)
2101{
2102        int rc = -ENOMEM, i;
2103        struct class_datum *match;
2104
2105        POLICY_RDLOCK;
2106
2107        match = hashtab_search(policydb.p_classes.table, class);
2108        if (!match) {
2109                printk(KERN_ERR "%s:  unrecognized class %s\n",
2110                        __FUNCTION__, class);
2111                rc = -EINVAL;
2112                goto out;
2113        }
2114
2115        *nperms = match->permissions.nprim;
2116        *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
2117        if (!*perms)
2118                goto out;
2119
2120        if (match->comdatum) {
2121                rc = hashtab_map(match->comdatum->permissions.table,
2122                                get_permissions_callback, *perms);
2123                if (rc < 0)
2124                        goto err;
2125        }
2126
2127        rc = hashtab_map(match->permissions.table, get_permissions_callback,
2128                        *perms);
2129        if (rc < 0)
2130                goto err;
2131
2132out:
2133        POLICY_RDUNLOCK;
2134        return rc;
2135
2136err:
2137        POLICY_RDUNLOCK;
2138        for (i = 0; i < *nperms; i++)
2139                kfree((*perms)[i]);
2140        kfree(*perms);
2141        return rc;
2142}
2143
2144int security_get_reject_unknown(void)
2145{
2146        return policydb.reject_unknown;
2147}
2148
2149int security_get_allow_unknown(void)
2150{
2151        return policydb.allow_unknown;
2152}
2153
2154struct selinux_audit_rule {
2155        u32 au_seqno;
2156        struct context au_ctxt;
2157};
2158
2159void selinux_audit_rule_free(struct selinux_audit_rule *rule)
2160{
2161        if (rule) {
2162                context_destroy(&rule->au_ctxt);
2163                kfree(rule);
2164        }
2165}
2166
2167int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
2168                            struct selinux_audit_rule **rule)
2169{
2170        struct selinux_audit_rule *tmprule;
2171        struct role_datum *roledatum;
2172        struct type_datum *typedatum;
2173        struct user_datum *userdatum;
2174        int rc = 0;
2175
2176        *rule = NULL;
2177
2178        if (!ss_initialized)
2179                return -EOPNOTSUPP;
2180
2181        switch (field) {
2182        case AUDIT_SUBJ_USER:
2183        case AUDIT_SUBJ_ROLE:
2184        case AUDIT_SUBJ_TYPE:
2185        case AUDIT_OBJ_USER:
2186        case AUDIT_OBJ_ROLE:
2187        case AUDIT_OBJ_TYPE:
2188                /* only 'equals' and 'not equals' fit user, role, and type */
2189                if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
2190                        return -EINVAL;
2191                break;
2192        case AUDIT_SUBJ_SEN:
2193        case AUDIT_SUBJ_CLR:
2194        case AUDIT_OBJ_LEV_LOW:
2195        case AUDIT_OBJ_LEV_HIGH:
2196                /* we do not allow a range, indicated by the presense of '-' */
2197                if (strchr(rulestr, '-'))
2198                        return -EINVAL;
2199                break;
2200        default:
2201                /* only the above fields are valid */
2202                return -EINVAL;
2203        }
2204
2205        tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
2206        if (!tmprule)
2207                return -ENOMEM;
2208
2209        context_init(&tmprule->au_ctxt);
2210
2211        POLICY_RDLOCK;
2212
2213        tmprule->au_seqno = latest_granting;
2214
2215        switch (field) {
2216        case AUDIT_SUBJ_USER:
2217        case AUDIT_OBJ_USER:
2218                userdatum = hashtab_search(policydb.p_users.table, rulestr);
2219                if (!userdatum)
2220                        rc = -EINVAL;
2221                else
2222                        tmprule->au_ctxt.user = userdatum->value;
2223                break;
2224        case AUDIT_SUBJ_ROLE:
2225        case AUDIT_OBJ_ROLE:
2226                roledatum = hashtab_search(policydb.p_roles.table, rulestr);
2227                if (!roledatum)
2228                        rc = -EINVAL;
2229                else
2230                        tmprule->au_ctxt.role = roledatum->value;
2231                break;
2232        case AUDIT_SUBJ_TYPE:
2233        case AUDIT_OBJ_TYPE:
2234                typedatum = hashtab_search(policydb.p_types.table, rulestr);
2235                if (!typedatum)
2236                        rc = -EINVAL;
2237                else
2238                        tmprule->au_ctxt.type = typedatum->value;
2239                break;
2240        case AUDIT_SUBJ_SEN:
2241        case AUDIT_SUBJ_CLR:
2242        case AUDIT_OBJ_LEV_LOW:
2243        case AUDIT_OBJ_LEV_HIGH:
2244                rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
2245                break;
2246        }
2247
2248        POLICY_RDUNLOCK;
2249
2250        if (rc) {
2251                selinux_audit_rule_free(tmprule);
2252                tmprule = NULL;
2253        }
2254
2255        *rule = tmprule;
2256
2257        return rc;
2258}
2259
2260int selinux_audit_rule_match(u32 sid, u32 field, u32 op,
2261                             struct selinux_audit_rule *rule,
2262                             struct audit_context *actx)
2263{
2264        struct context *ctxt;
2265        struct mls_level *level;
2266        int match = 0;
2267
2268        if (!rule) {
2269                audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2270                          "selinux_audit_rule_match: missing rule\n");
2271                return -ENOENT;
2272        }
2273
2274        POLICY_RDLOCK;
2275
2276        if (rule->au_seqno < latest_granting) {
2277                audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2278                          "selinux_audit_rule_match: stale rule\n");
2279                match = -ESTALE;
2280                goto out;
2281        }
2282
2283        ctxt = sidtab_search(&sidtab, sid);
2284        if (!ctxt) {
2285                audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
2286                          "selinux_audit_rule_match: unrecognized SID %d\n",
2287                          sid);
2288                match = -ENOENT;
2289                goto out;
2290        }
2291
2292        /* a field/op pair that is not caught here will simply fall through
2293           without a match */
2294        switch (field) {
2295        case AUDIT_SUBJ_USER:
2296        case AUDIT_OBJ_USER:
2297                switch (op) {
2298                case AUDIT_EQUAL:
2299                        match = (ctxt->user == rule->au_ctxt.user);
2300                        break;
2301                case AUDIT_NOT_EQUAL:
2302                        match = (ctxt->user != rule->au_ctxt.user);
2303                        break;
2304                }
2305                break;
2306        case AUDIT_SUBJ_ROLE:
2307        case AUDIT_OBJ_ROLE:
2308                switch (op) {
2309                case AUDIT_EQUAL:
2310                        match = (ctxt->role == rule->au_ctxt.role);
2311                        break;
2312                case AUDIT_NOT_EQUAL:
2313                        match = (ctxt->role != rule->au_ctxt.role);
2314                        break;
2315                }
2316                break;
2317        case AUDIT_SUBJ_TYPE:
2318        case AUDIT_OBJ_TYPE:
2319                switch (op) {
2320                case AUDIT_EQUAL:
2321                        match = (ctxt->type == rule->au_ctxt.type);
2322                        break;
2323                case AUDIT_NOT_EQUAL:
2324                        match = (ctxt->type != rule->au_ctxt.type);
2325                        break;
2326                }
2327                break;
2328        case AUDIT_SUBJ_SEN:
2329        case AUDIT_SUBJ_CLR:
2330        case AUDIT_OBJ_LEV_LOW:
2331        case AUDIT_OBJ_LEV_HIGH:
2332                level = ((field == AUDIT_SUBJ_SEN ||
2333                          field == AUDIT_OBJ_LEV_LOW) ?
2334                         &ctxt->range.level[0] : &ctxt->range.level[1]);
2335                switch (op) {
2336                case AUDIT_EQUAL:
2337                        match = mls_level_eq(&rule->au_ctxt.range.level[0],
2338                                             level);
2339                        break;
2340                case AUDIT_NOT_EQUAL:
2341                        match = !mls_level_eq(&rule->au_ctxt.range.level[0],
2342                                              level);
2343                        break;
2344                case AUDIT_LESS_THAN:
2345                        match = (mls_level_dom(&rule->au_ctxt.range.level[0],
2346                                               level) &&
2347                                 !mls_level_eq(&rule->au_ctxt.range.level[0],
2348                                               level));
2349                        break;
2350                case AUDIT_LESS_THAN_OR_EQUAL:
2351                        match = mls_level_dom(&rule->au_ctxt.range.level[0],
2352                                              level);
2353                        break;
2354                case AUDIT_GREATER_THAN:
2355                        match = (mls_level_dom(level,
2356                                              &rule->au_ctxt.range.level[0]) &&
2357                                 !mls_level_eq(level,
2358                                               &rule->au_ctxt.range.level[0]));
2359                        break;
2360                case AUDIT_GREATER_THAN_OR_EQUAL:
2361                        match = mls_level_dom(level,
2362                                              &rule->au_ctxt.range.level[0]);
2363                        break;
2364                }
2365        }
2366
2367out:
2368        POLICY_RDUNLOCK;
2369        return match;
2370}
2371
2372static int (*aurule_callback)(void) = NULL;
2373
2374static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
2375                               u16 class, u32 perms, u32 *retained)
2376{
2377        int err = 0;
2378
2379        if (event == AVC_CALLBACK_RESET && aurule_callback)
2380                err = aurule_callback();
2381        return err;
2382}
2383
2384static int __init aurule_init(void)
2385{
2386        int err;
2387
2388        err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
2389                               SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
2390        if (err)
2391                panic("avc_add_callback() failed, error %d\n", err);
2392
2393        return err;
2394}
2395__initcall(aurule_init);
2396
2397void selinux_audit_set_callback(int (*callback)(void))
2398{
2399        aurule_callback = callback;
2400}
2401
2402#ifdef CONFIG_NETLABEL
2403/*
2404 * NetLabel cache structure
2405 */
2406#define NETLBL_CACHE(x)           ((struct selinux_netlbl_cache *)(x))
2407#define NETLBL_CACHE_T_NONE       0
2408#define NETLBL_CACHE_T_SID        1
2409#define NETLBL_CACHE_T_MLS        2
2410struct selinux_netlbl_cache {
2411        u32 type;
2412        union {
2413                u32 sid;
2414                struct mls_range mls_label;
2415        } data;
2416};
2417
2418/**
2419 * security_netlbl_cache_free - Free the NetLabel cached data
2420 * @data: the data to free
2421 *
2422 * Description:
2423 * This function is intended to be used as the free() callback inside the
2424 * netlbl_lsm_cache structure.
2425 *
2426 */
2427static void security_netlbl_cache_free(const void *data)
2428{
2429        struct selinux_netlbl_cache *cache;
2430
2431        if (data == NULL)
2432                return;
2433
2434        cache = NETLBL_CACHE(data);
2435        switch (cache->type) {
2436        case NETLBL_CACHE_T_MLS:
2437                ebitmap_destroy(&cache->data.mls_label.level[0].cat);
2438                break;
2439        }
2440        kfree(data);
2441}
2442
2443/**
2444 * security_netlbl_cache_add - Add an entry to the NetLabel cache
2445 * @secattr: the NetLabel packet security attributes
2446 * @ctx: the SELinux context
2447 *
2448 * Description:
2449 * Attempt to cache the context in @ctx, which was derived from the packet in
2450 * @skb, in the NetLabel subsystem cache.  This function assumes @secattr has
2451 * already been initialized.
2452 *
2453 */
2454static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
2455                                      struct context *ctx)
2456{
2457        struct selinux_netlbl_cache *cache = NULL;
2458
2459        secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
2460        if (secattr->cache == NULL)
2461                return;
2462
2463        cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
2464        if (cache == NULL)
2465                return;
2466
2467        cache->type = NETLBL_CACHE_T_MLS;
2468        if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
2469                        &ctx->range.level[0].cat) != 0) {
2470                kfree(cache);
2471                return;
2472        }
2473        cache->data.mls_label.level[1].cat.highbit =
2474                cache->data.mls_label.level[0].cat.highbit;
2475        cache->data.mls_label.level[1].cat.node =
2476                cache->data.mls_label.level[0].cat.node;
2477        cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
2478        cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
2479
2480        secattr->cache->free = security_netlbl_cache_free;
2481        secattr->cache->data = (void *)cache;
2482        secattr->flags |= NETLBL_SECATTR_CACHE;
2483}
2484
2485/**
2486 * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
2487 * @secattr: the NetLabel packet security attributes
2488 * @base_sid: the SELinux SID to use as a context for MLS only attributes
2489 * @sid: the SELinux SID
2490 *
2491 * Description:
2492 * Convert the given NetLabel security attributes in @secattr into a
2493 * SELinux SID.  If the @secattr field does not contain a full SELinux
2494 * SID/context then use the context in @base_sid as the foundation.  If
2495 * possibile the 'cache' field of @secattr is set and the CACHE flag is set;
2496 * this is to allow the @secattr to be used by NetLabel to cache the secattr to
2497 * SID conversion for future lookups.  Returns zero on success, negative
2498 * values on failure.
2499 *
2500 */
2501int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
2502                                   u32 base_sid,
2503                                   u32 *sid)
2504{
2505        int rc = -EIDRM;
2506        struct context *ctx;
2507        struct context ctx_new;
2508        struct selinux_netlbl_cache *cache;
2509
2510        if (!ss_initialized) {
2511                *sid = SECSID_NULL;
2512                return 0;
2513        }
2514
2515        POLICY_RDLOCK;
2516
2517        if (secattr->flags & NETLBL_SECATTR_CACHE) {
2518                cache = NETLBL_CACHE(secattr->cache->data);
2519                switch (cache->type) {
2520                case NETLBL_CACHE_T_SID:
2521                        *sid = cache->data.sid;
2522                        rc = 0;
2523                        break;
2524                case NETLBL_CACHE_T_MLS:
2525                        ctx = sidtab_search(&sidtab, base_sid);
2526                        if (ctx == NULL)
2527                                goto netlbl_secattr_to_sid_return;
2528
2529                        ctx_new.user = ctx->user;
2530                        ctx_new.role = ctx->role;
2531                        ctx_new.type = ctx->type;
2532                        ctx_new.range.level[0].sens =
2533                                cache->data.mls_label.level[0].sens;
2534                        ctx_new.range.level[0].cat.highbit =
2535                                cache->data.mls_label.level[0].cat.highbit;
2536                        ctx_new.range.level[0].cat.node =
2537                                cache->data.mls_label.level[0].cat.node;
2538                        ctx_new.range.level[1].sens =
2539                                cache->data.mls_label.level[1].sens;
2540                        ctx_new.range.level[1].cat.highbit =
2541                                cache->data.mls_label.level[1].cat.highbit;
2542                        ctx_new.range.level[1].cat.node =
2543                                cache->data.mls_label.level[1].cat.node;
2544
2545                        rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2546                        break;
2547                default:
2548                        goto netlbl_secattr_to_sid_return;
2549                }
2550        } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
2551                ctx = sidtab_search(&sidtab, base_sid);
2552                if (ctx == NULL)
2553                        goto netlbl_secattr_to_sid_return;
2554
2555                ctx_new.user = ctx->user;
2556                ctx_new.role = ctx->role;
2557                ctx_new.type = ctx->type;
2558                mls_import_netlbl_lvl(&ctx_new, secattr);
2559                if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
2560                        if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
2561                                                  secattr->mls_cat) != 0)
2562                                goto netlbl_secattr_to_sid_return;
2563                        ctx_new.range.level[1].cat.highbit =
2564                                ctx_new.range.level[0].cat.highbit;
2565                        ctx_new.range.level[1].cat.node =
2566                                ctx_new.range.level[0].cat.node;
2567                } else {
2568                        ebitmap_init(&ctx_new.range.level[0].cat);
2569                        ebitmap_init(&ctx_new.range.level[1].cat);
2570                }
2571                if (mls_context_isvalid(&policydb, &ctx_new) != 1)
2572                        goto netlbl_secattr_to_sid_return_cleanup;
2573
2574                rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
2575                if (rc != 0)
2576                        goto netlbl_secattr_to_sid_return_cleanup;
2577
2578                security_netlbl_cache_add(secattr, &ctx_new);
2579
2580                ebitmap_destroy(&ctx_new.range.level[0].cat);
2581        } else {
2582                *sid = SECSID_NULL;
2583                rc = 0;
2584        }
2585
2586netlbl_secattr_to_sid_return:
2587        POLICY_RDUNLOCK;
2588        return rc;
2589netlbl_secattr_to_sid_return_cleanup:
2590        ebitmap_destroy(&ctx_new.range.level[0].cat);
2591        goto netlbl_secattr_to_sid_return;
2592}
2593
2594/**
2595 * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr
2596 * @sid: the SELinux SID
2597 * @secattr: the NetLabel packet security attributes
2598 *
2599 * Description:
2600 * Convert the given SELinux SID in @sid into a NetLabel security attribute.
2601 * Returns zero on success, negative values on failure.
2602 *
2603 */
2604int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
2605{
2606        int rc = -ENOENT;
2607        struct context *ctx;
2608
2609        if (!ss_initialized)
2610                return 0;
2611
2612        POLICY_RDLOCK;
2613        ctx = sidtab_search(&sidtab, sid);
2614        if (ctx == NULL)
2615                goto netlbl_sid_to_secattr_failure;
2616        secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
2617                                  GFP_ATOMIC);
2618        secattr->flags |= NETLBL_SECATTR_DOMAIN;
2619        mls_export_netlbl_lvl(ctx, secattr);
2620        rc = mls_export_netlbl_cat(ctx, secattr);
2621        if (rc != 0)
2622                goto netlbl_sid_to_secattr_failure;
2623        POLICY_RDUNLOCK;
2624
2625        return 0;
2626
2627netlbl_sid_to_secattr_failure:
2628        POLICY_RDUNLOCK;
2629        netlbl_secattr_destroy(secattr);
2630        return rc;
2631}
2632#endif /* CONFIG_NETLABEL */
2633