linux/security/smack/smack_lsm.c
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   1/*
   2 *  Simplified MAC Kernel (smack) security module
   3 *
   4 *  This file contains the smack hook function implementations.
   5 *
   6 *  Authors:
   7 *      Casey Schaufler <casey@schaufler-ca.com>
   8 *      Jarkko Sakkinen <jarkko.sakkinen@intel.com>
   9 *
  10 *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
  11 *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
  12 *                Paul Moore <paul@paul-moore.com>
  13 *  Copyright (C) 2010 Nokia Corporation
  14 *  Copyright (C) 2011 Intel Corporation.
  15 *
  16 *      This program is free software; you can redistribute it and/or modify
  17 *      it under the terms of the GNU General Public License version 2,
  18 *      as published by the Free Software Foundation.
  19 */
  20
  21#include <linux/xattr.h>
  22#include <linux/pagemap.h>
  23#include <linux/mount.h>
  24#include <linux/stat.h>
  25#include <linux/kd.h>
  26#include <asm/ioctls.h>
  27#include <linux/ip.h>
  28#include <linux/tcp.h>
  29#include <linux/udp.h>
  30#include <linux/slab.h>
  31#include <linux/mutex.h>
  32#include <linux/pipe_fs_i.h>
  33#include <net/cipso_ipv4.h>
  34#include <linux/audit.h>
  35#include <linux/magic.h>
  36#include <linux/dcache.h>
  37#include <linux/personality.h>
  38#include <linux/msg.h>
  39#include <linux/shm.h>
  40#include <linux/binfmts.h>
  41#include "smack.h"
  42
  43#define task_security(task)     (task_cred_xxx((task), security))
  44
  45#define TRANS_TRUE      "TRUE"
  46#define TRANS_TRUE_SIZE 4
  47
  48/**
  49 * smk_fetch - Fetch the smack label from a file.
  50 * @ip: a pointer to the inode
  51 * @dp: a pointer to the dentry
  52 *
  53 * Returns a pointer to the master list entry for the Smack label
  54 * or NULL if there was no label to fetch.
  55 */
  56static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
  57{
  58        int rc;
  59        char *buffer;
  60        char *result = NULL;
  61
  62        if (ip->i_op->getxattr == NULL)
  63                return NULL;
  64
  65        buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
  66        if (buffer == NULL)
  67                return NULL;
  68
  69        rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
  70        if (rc > 0)
  71                result = smk_import(buffer, rc);
  72
  73        kfree(buffer);
  74
  75        return result;
  76}
  77
  78/**
  79 * new_inode_smack - allocate an inode security blob
  80 * @smack: a pointer to the Smack label to use in the blob
  81 *
  82 * Returns the new blob or NULL if there's no memory available
  83 */
  84struct inode_smack *new_inode_smack(char *smack)
  85{
  86        struct inode_smack *isp;
  87
  88        isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);
  89        if (isp == NULL)
  90                return NULL;
  91
  92        isp->smk_inode = smack;
  93        isp->smk_flags = 0;
  94        mutex_init(&isp->smk_lock);
  95
  96        return isp;
  97}
  98
  99/**
 100 * new_task_smack - allocate a task security blob
 101 * @smack: a pointer to the Smack label to use in the blob
 102 *
 103 * Returns the new blob or NULL if there's no memory available
 104 */
 105static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
 106{
 107        struct task_smack *tsp;
 108
 109        tsp = kzalloc(sizeof(struct task_smack), gfp);
 110        if (tsp == NULL)
 111                return NULL;
 112
 113        tsp->smk_task = task;
 114        tsp->smk_forked = forked;
 115        INIT_LIST_HEAD(&tsp->smk_rules);
 116        mutex_init(&tsp->smk_rules_lock);
 117
 118        return tsp;
 119}
 120
 121/**
 122 * smk_copy_rules - copy a rule set
 123 * @nhead - new rules header pointer
 124 * @ohead - old rules header pointer
 125 *
 126 * Returns 0 on success, -ENOMEM on error
 127 */
 128static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
 129                                gfp_t gfp)
 130{
 131        struct smack_rule *nrp;
 132        struct smack_rule *orp;
 133        int rc = 0;
 134
 135        INIT_LIST_HEAD(nhead);
 136
 137        list_for_each_entry_rcu(orp, ohead, list) {
 138                nrp = kzalloc(sizeof(struct smack_rule), gfp);
 139                if (nrp == NULL) {
 140                        rc = -ENOMEM;
 141                        break;
 142                }
 143                *nrp = *orp;
 144                list_add_rcu(&nrp->list, nhead);
 145        }
 146        return rc;
 147}
 148
 149/*
 150 * LSM hooks.
 151 * We he, that is fun!
 152 */
 153
 154/**
 155 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
 156 * @ctp: child task pointer
 157 * @mode: ptrace attachment mode
 158 *
 159 * Returns 0 if access is OK, an error code otherwise
 160 *
 161 * Do the capability checks, and require read and write.
 162 */
 163static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
 164{
 165        int rc;
 166        struct smk_audit_info ad;
 167        char *tsp;
 168
 169        rc = cap_ptrace_access_check(ctp, mode);
 170        if (rc != 0)
 171                return rc;
 172
 173        tsp = smk_of_task(task_security(ctp));
 174        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
 175        smk_ad_setfield_u_tsk(&ad, ctp);
 176
 177        rc = smk_curacc(tsp, MAY_READWRITE, &ad);
 178        return rc;
 179}
 180
 181/**
 182 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
 183 * @ptp: parent task pointer
 184 *
 185 * Returns 0 if access is OK, an error code otherwise
 186 *
 187 * Do the capability checks, and require read and write.
 188 */
 189static int smack_ptrace_traceme(struct task_struct *ptp)
 190{
 191        int rc;
 192        struct smk_audit_info ad;
 193        char *tsp;
 194
 195        rc = cap_ptrace_traceme(ptp);
 196        if (rc != 0)
 197                return rc;
 198
 199        tsp = smk_of_task(task_security(ptp));
 200        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
 201        smk_ad_setfield_u_tsk(&ad, ptp);
 202
 203        rc = smk_curacc(tsp, MAY_READWRITE, &ad);
 204        return rc;
 205}
 206
 207/**
 208 * smack_syslog - Smack approval on syslog
 209 * @type: message type
 210 *
 211 * Require that the task has the floor label
 212 *
 213 * Returns 0 on success, error code otherwise.
 214 */
 215static int smack_syslog(int typefrom_file)
 216{
 217        int rc = 0;
 218        char *sp = smk_of_current();
 219
 220        if (smack_privileged(CAP_MAC_OVERRIDE))
 221                return 0;
 222
 223         if (sp != smack_known_floor.smk_known)
 224                rc = -EACCES;
 225
 226        return rc;
 227}
 228
 229
 230/*
 231 * Superblock Hooks.
 232 */
 233
 234/**
 235 * smack_sb_alloc_security - allocate a superblock blob
 236 * @sb: the superblock getting the blob
 237 *
 238 * Returns 0 on success or -ENOMEM on error.
 239 */
 240static int smack_sb_alloc_security(struct super_block *sb)
 241{
 242        struct superblock_smack *sbsp;
 243
 244        sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
 245
 246        if (sbsp == NULL)
 247                return -ENOMEM;
 248
 249        sbsp->smk_root = smack_known_floor.smk_known;
 250        sbsp->smk_default = smack_known_floor.smk_known;
 251        sbsp->smk_floor = smack_known_floor.smk_known;
 252        sbsp->smk_hat = smack_known_hat.smk_known;
 253        sbsp->smk_initialized = 0;
 254
 255        sb->s_security = sbsp;
 256
 257        return 0;
 258}
 259
 260/**
 261 * smack_sb_free_security - free a superblock blob
 262 * @sb: the superblock getting the blob
 263 *
 264 */
 265static void smack_sb_free_security(struct super_block *sb)
 266{
 267        kfree(sb->s_security);
 268        sb->s_security = NULL;
 269}
 270
 271/**
 272 * smack_sb_copy_data - copy mount options data for processing
 273 * @orig: where to start
 274 * @smackopts: mount options string
 275 *
 276 * Returns 0 on success or -ENOMEM on error.
 277 *
 278 * Copy the Smack specific mount options out of the mount
 279 * options list.
 280 */
 281static int smack_sb_copy_data(char *orig, char *smackopts)
 282{
 283        char *cp, *commap, *otheropts, *dp;
 284
 285        otheropts = (char *)get_zeroed_page(GFP_KERNEL);
 286        if (otheropts == NULL)
 287                return -ENOMEM;
 288
 289        for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
 290                if (strstr(cp, SMK_FSDEFAULT) == cp)
 291                        dp = smackopts;
 292                else if (strstr(cp, SMK_FSFLOOR) == cp)
 293                        dp = smackopts;
 294                else if (strstr(cp, SMK_FSHAT) == cp)
 295                        dp = smackopts;
 296                else if (strstr(cp, SMK_FSROOT) == cp)
 297                        dp = smackopts;
 298                else
 299                        dp = otheropts;
 300
 301                commap = strchr(cp, ',');
 302                if (commap != NULL)
 303                        *commap = '\0';
 304
 305                if (*dp != '\0')
 306                        strcat(dp, ",");
 307                strcat(dp, cp);
 308        }
 309
 310        strcpy(orig, otheropts);
 311        free_page((unsigned long)otheropts);
 312
 313        return 0;
 314}
 315
 316/**
 317 * smack_sb_kern_mount - Smack specific mount processing
 318 * @sb: the file system superblock
 319 * @flags: the mount flags
 320 * @data: the smack mount options
 321 *
 322 * Returns 0 on success, an error code on failure
 323 */
 324static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
 325{
 326        struct dentry *root = sb->s_root;
 327        struct inode *inode = root->d_inode;
 328        struct superblock_smack *sp = sb->s_security;
 329        struct inode_smack *isp;
 330        char *op;
 331        char *commap;
 332        char *nsp;
 333
 334        if (sp->smk_initialized != 0)
 335                return 0;
 336
 337        sp->smk_initialized = 1;
 338
 339        for (op = data; op != NULL; op = commap) {
 340                commap = strchr(op, ',');
 341                if (commap != NULL)
 342                        *commap++ = '\0';
 343
 344                if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
 345                        op += strlen(SMK_FSHAT);
 346                        nsp = smk_import(op, 0);
 347                        if (nsp != NULL)
 348                                sp->smk_hat = nsp;
 349                } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
 350                        op += strlen(SMK_FSFLOOR);
 351                        nsp = smk_import(op, 0);
 352                        if (nsp != NULL)
 353                                sp->smk_floor = nsp;
 354                } else if (strncmp(op, SMK_FSDEFAULT,
 355                                   strlen(SMK_FSDEFAULT)) == 0) {
 356                        op += strlen(SMK_FSDEFAULT);
 357                        nsp = smk_import(op, 0);
 358                        if (nsp != NULL)
 359                                sp->smk_default = nsp;
 360                } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
 361                        op += strlen(SMK_FSROOT);
 362                        nsp = smk_import(op, 0);
 363                        if (nsp != NULL)
 364                                sp->smk_root = nsp;
 365                }
 366        }
 367
 368        /*
 369         * Initialize the root inode.
 370         */
 371        isp = inode->i_security;
 372        if (isp == NULL)
 373                inode->i_security = new_inode_smack(sp->smk_root);
 374        else
 375                isp->smk_inode = sp->smk_root;
 376
 377        return 0;
 378}
 379
 380/**
 381 * smack_sb_statfs - Smack check on statfs
 382 * @dentry: identifies the file system in question
 383 *
 384 * Returns 0 if current can read the floor of the filesystem,
 385 * and error code otherwise
 386 */
 387static int smack_sb_statfs(struct dentry *dentry)
 388{
 389        struct superblock_smack *sbp = dentry->d_sb->s_security;
 390        int rc;
 391        struct smk_audit_info ad;
 392
 393        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 394        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 395
 396        rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
 397        return rc;
 398}
 399
 400/**
 401 * smack_sb_mount - Smack check for mounting
 402 * @dev_name: unused
 403 * @path: mount point
 404 * @type: unused
 405 * @flags: unused
 406 * @data: unused
 407 *
 408 * Returns 0 if current can write the floor of the filesystem
 409 * being mounted on, an error code otherwise.
 410 */
 411static int smack_sb_mount(char *dev_name, struct path *path,
 412                          char *type, unsigned long flags, void *data)
 413{
 414        struct superblock_smack *sbp = path->dentry->d_sb->s_security;
 415        struct smk_audit_info ad;
 416
 417        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 418        smk_ad_setfield_u_fs_path(&ad, *path);
 419
 420        return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
 421}
 422
 423/**
 424 * smack_sb_umount - Smack check for unmounting
 425 * @mnt: file system to unmount
 426 * @flags: unused
 427 *
 428 * Returns 0 if current can write the floor of the filesystem
 429 * being unmounted, an error code otherwise.
 430 */
 431static int smack_sb_umount(struct vfsmount *mnt, int flags)
 432{
 433        struct superblock_smack *sbp;
 434        struct smk_audit_info ad;
 435        struct path path;
 436
 437        path.dentry = mnt->mnt_root;
 438        path.mnt = mnt;
 439
 440        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 441        smk_ad_setfield_u_fs_path(&ad, path);
 442
 443        sbp = path.dentry->d_sb->s_security;
 444        return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
 445}
 446
 447/*
 448 * BPRM hooks
 449 */
 450
 451/**
 452 * smack_bprm_set_creds - set creds for exec
 453 * @bprm: the exec information
 454 *
 455 * Returns 0 if it gets a blob, -ENOMEM otherwise
 456 */
 457static int smack_bprm_set_creds(struct linux_binprm *bprm)
 458{
 459        struct inode *inode = bprm->file->f_path.dentry->d_inode;
 460        struct task_smack *bsp = bprm->cred->security;
 461        struct inode_smack *isp;
 462        int rc;
 463
 464        rc = cap_bprm_set_creds(bprm);
 465        if (rc != 0)
 466                return rc;
 467
 468        if (bprm->cred_prepared)
 469                return 0;
 470
 471        isp = inode->i_security;
 472        if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
 473                return 0;
 474
 475        if (bprm->unsafe)
 476                return -EPERM;
 477
 478        bsp->smk_task = isp->smk_task;
 479        bprm->per_clear |= PER_CLEAR_ON_SETID;
 480
 481        return 0;
 482}
 483
 484/**
 485 * smack_bprm_committing_creds - Prepare to install the new credentials
 486 * from bprm.
 487 *
 488 * @bprm: binprm for exec
 489 */
 490static void smack_bprm_committing_creds(struct linux_binprm *bprm)
 491{
 492        struct task_smack *bsp = bprm->cred->security;
 493
 494        if (bsp->smk_task != bsp->smk_forked)
 495                current->pdeath_signal = 0;
 496}
 497
 498/**
 499 * smack_bprm_secureexec - Return the decision to use secureexec.
 500 * @bprm: binprm for exec
 501 *
 502 * Returns 0 on success.
 503 */
 504static int smack_bprm_secureexec(struct linux_binprm *bprm)
 505{
 506        struct task_smack *tsp = current_security();
 507        int ret = cap_bprm_secureexec(bprm);
 508
 509        if (!ret && (tsp->smk_task != tsp->smk_forked))
 510                ret = 1;
 511
 512        return ret;
 513}
 514
 515/*
 516 * Inode hooks
 517 */
 518
 519/**
 520 * smack_inode_alloc_security - allocate an inode blob
 521 * @inode: the inode in need of a blob
 522 *
 523 * Returns 0 if it gets a blob, -ENOMEM otherwise
 524 */
 525static int smack_inode_alloc_security(struct inode *inode)
 526{
 527        inode->i_security = new_inode_smack(smk_of_current());
 528        if (inode->i_security == NULL)
 529                return -ENOMEM;
 530        return 0;
 531}
 532
 533/**
 534 * smack_inode_free_security - free an inode blob
 535 * @inode: the inode with a blob
 536 *
 537 * Clears the blob pointer in inode
 538 */
 539static void smack_inode_free_security(struct inode *inode)
 540{
 541        kfree(inode->i_security);
 542        inode->i_security = NULL;
 543}
 544
 545/**
 546 * smack_inode_init_security - copy out the smack from an inode
 547 * @inode: the inode
 548 * @dir: unused
 549 * @qstr: unused
 550 * @name: where to put the attribute name
 551 * @value: where to put the attribute value
 552 * @len: where to put the length of the attribute
 553 *
 554 * Returns 0 if it all works out, -ENOMEM if there's no memory
 555 */
 556static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 557                                     const struct qstr *qstr, char **name,
 558                                     void **value, size_t *len)
 559{
 560        struct smack_known *skp;
 561        struct inode_smack *issp = inode->i_security;
 562        char *csp = smk_of_current();
 563        char *isp = smk_of_inode(inode);
 564        char *dsp = smk_of_inode(dir);
 565        int may;
 566
 567        if (name) {
 568                *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_NOFS);
 569                if (*name == NULL)
 570                        return -ENOMEM;
 571        }
 572
 573        if (value) {
 574                skp = smk_find_entry(csp);
 575                rcu_read_lock();
 576                may = smk_access_entry(csp, dsp, &skp->smk_rules);
 577                rcu_read_unlock();
 578
 579                /*
 580                 * If the access rule allows transmutation and
 581                 * the directory requests transmutation then
 582                 * by all means transmute.
 583                 * Mark the inode as changed.
 584                 */
 585                if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
 586                    smk_inode_transmutable(dir)) {
 587                        isp = dsp;
 588                        issp->smk_flags |= SMK_INODE_CHANGED;
 589                }
 590
 591                *value = kstrdup(isp, GFP_NOFS);
 592                if (*value == NULL)
 593                        return -ENOMEM;
 594        }
 595
 596        if (len)
 597                *len = strlen(isp) + 1;
 598
 599        return 0;
 600}
 601
 602/**
 603 * smack_inode_link - Smack check on link
 604 * @old_dentry: the existing object
 605 * @dir: unused
 606 * @new_dentry: the new object
 607 *
 608 * Returns 0 if access is permitted, an error code otherwise
 609 */
 610static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
 611                            struct dentry *new_dentry)
 612{
 613        char *isp;
 614        struct smk_audit_info ad;
 615        int rc;
 616
 617        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 618        smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
 619
 620        isp = smk_of_inode(old_dentry->d_inode);
 621        rc = smk_curacc(isp, MAY_WRITE, &ad);
 622
 623        if (rc == 0 && new_dentry->d_inode != NULL) {
 624                isp = smk_of_inode(new_dentry->d_inode);
 625                smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
 626                rc = smk_curacc(isp, MAY_WRITE, &ad);
 627        }
 628
 629        return rc;
 630}
 631
 632/**
 633 * smack_inode_unlink - Smack check on inode deletion
 634 * @dir: containing directory object
 635 * @dentry: file to unlink
 636 *
 637 * Returns 0 if current can write the containing directory
 638 * and the object, error code otherwise
 639 */
 640static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
 641{
 642        struct inode *ip = dentry->d_inode;
 643        struct smk_audit_info ad;
 644        int rc;
 645
 646        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 647        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 648
 649        /*
 650         * You need write access to the thing you're unlinking
 651         */
 652        rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
 653        if (rc == 0) {
 654                /*
 655                 * You also need write access to the containing directory
 656                 */
 657                smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
 658                smk_ad_setfield_u_fs_inode(&ad, dir);
 659                rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
 660        }
 661        return rc;
 662}
 663
 664/**
 665 * smack_inode_rmdir - Smack check on directory deletion
 666 * @dir: containing directory object
 667 * @dentry: directory to unlink
 668 *
 669 * Returns 0 if current can write the containing directory
 670 * and the directory, error code otherwise
 671 */
 672static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
 673{
 674        struct smk_audit_info ad;
 675        int rc;
 676
 677        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 678        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 679
 680        /*
 681         * You need write access to the thing you're removing
 682         */
 683        rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 684        if (rc == 0) {
 685                /*
 686                 * You also need write access to the containing directory
 687                 */
 688                smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
 689                smk_ad_setfield_u_fs_inode(&ad, dir);
 690                rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
 691        }
 692
 693        return rc;
 694}
 695
 696/**
 697 * smack_inode_rename - Smack check on rename
 698 * @old_inode: the old directory
 699 * @old_dentry: unused
 700 * @new_inode: the new directory
 701 * @new_dentry: unused
 702 *
 703 * Read and write access is required on both the old and
 704 * new directories.
 705 *
 706 * Returns 0 if access is permitted, an error code otherwise
 707 */
 708static int smack_inode_rename(struct inode *old_inode,
 709                              struct dentry *old_dentry,
 710                              struct inode *new_inode,
 711                              struct dentry *new_dentry)
 712{
 713        int rc;
 714        char *isp;
 715        struct smk_audit_info ad;
 716
 717        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 718        smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
 719
 720        isp = smk_of_inode(old_dentry->d_inode);
 721        rc = smk_curacc(isp, MAY_READWRITE, &ad);
 722
 723        if (rc == 0 && new_dentry->d_inode != NULL) {
 724                isp = smk_of_inode(new_dentry->d_inode);
 725                smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
 726                rc = smk_curacc(isp, MAY_READWRITE, &ad);
 727        }
 728        return rc;
 729}
 730
 731/**
 732 * smack_inode_permission - Smack version of permission()
 733 * @inode: the inode in question
 734 * @mask: the access requested
 735 *
 736 * This is the important Smack hook.
 737 *
 738 * Returns 0 if access is permitted, -EACCES otherwise
 739 */
 740static int smack_inode_permission(struct inode *inode, int mask)
 741{
 742        struct smk_audit_info ad;
 743        int no_block = mask & MAY_NOT_BLOCK;
 744
 745        mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
 746        /*
 747         * No permission to check. Existence test. Yup, it's there.
 748         */
 749        if (mask == 0)
 750                return 0;
 751
 752        /* May be droppable after audit */
 753        if (no_block)
 754                return -ECHILD;
 755        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
 756        smk_ad_setfield_u_fs_inode(&ad, inode);
 757        return smk_curacc(smk_of_inode(inode), mask, &ad);
 758}
 759
 760/**
 761 * smack_inode_setattr - Smack check for setting attributes
 762 * @dentry: the object
 763 * @iattr: for the force flag
 764 *
 765 * Returns 0 if access is permitted, an error code otherwise
 766 */
 767static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
 768{
 769        struct smk_audit_info ad;
 770        /*
 771         * Need to allow for clearing the setuid bit.
 772         */
 773        if (iattr->ia_valid & ATTR_FORCE)
 774                return 0;
 775        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 776        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 777
 778        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 779}
 780
 781/**
 782 * smack_inode_getattr - Smack check for getting attributes
 783 * @mnt: unused
 784 * @dentry: the object
 785 *
 786 * Returns 0 if access is permitted, an error code otherwise
 787 */
 788static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 789{
 790        struct smk_audit_info ad;
 791        struct path path;
 792
 793        path.dentry = dentry;
 794        path.mnt = mnt;
 795
 796        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
 797        smk_ad_setfield_u_fs_path(&ad, path);
 798        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
 799}
 800
 801/**
 802 * smack_inode_setxattr - Smack check for setting xattrs
 803 * @dentry: the object
 804 * @name: name of the attribute
 805 * @value: unused
 806 * @size: unused
 807 * @flags: unused
 808 *
 809 * This protects the Smack attribute explicitly.
 810 *
 811 * Returns 0 if access is permitted, an error code otherwise
 812 */
 813static int smack_inode_setxattr(struct dentry *dentry, const char *name,
 814                                const void *value, size_t size, int flags)
 815{
 816        struct smk_audit_info ad;
 817        int rc = 0;
 818
 819        if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
 820            strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
 821            strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
 822            strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
 823            strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
 824                if (!smack_privileged(CAP_MAC_ADMIN))
 825                        rc = -EPERM;
 826                /*
 827                 * check label validity here so import wont fail on
 828                 * post_setxattr
 829                 */
 830                if (size == 0 || size >= SMK_LONGLABEL ||
 831                    smk_import(value, size) == NULL)
 832                        rc = -EINVAL;
 833        } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
 834                if (!smack_privileged(CAP_MAC_ADMIN))
 835                        rc = -EPERM;
 836                if (size != TRANS_TRUE_SIZE ||
 837                    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
 838                        rc = -EINVAL;
 839        } else
 840                rc = cap_inode_setxattr(dentry, name, value, size, flags);
 841
 842        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 843        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 844
 845        if (rc == 0)
 846                rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 847
 848        return rc;
 849}
 850
 851/**
 852 * smack_inode_post_setxattr - Apply the Smack update approved above
 853 * @dentry: object
 854 * @name: attribute name
 855 * @value: attribute value
 856 * @size: attribute size
 857 * @flags: unused
 858 *
 859 * Set the pointer in the inode blob to the entry found
 860 * in the master label list.
 861 */
 862static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
 863                                      const void *value, size_t size, int flags)
 864{
 865        char *nsp;
 866        struct inode_smack *isp = dentry->d_inode->i_security;
 867
 868        if (strcmp(name, XATTR_NAME_SMACK) == 0) {
 869                nsp = smk_import(value, size);
 870                if (nsp != NULL)
 871                        isp->smk_inode = nsp;
 872                else
 873                        isp->smk_inode = smack_known_invalid.smk_known;
 874        } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
 875                nsp = smk_import(value, size);
 876                if (nsp != NULL)
 877                        isp->smk_task = nsp;
 878                else
 879                        isp->smk_task = smack_known_invalid.smk_known;
 880        } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
 881                nsp = smk_import(value, size);
 882                if (nsp != NULL)
 883                        isp->smk_mmap = nsp;
 884                else
 885                        isp->smk_mmap = smack_known_invalid.smk_known;
 886        } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
 887                isp->smk_flags |= SMK_INODE_TRANSMUTE;
 888
 889        return;
 890}
 891
 892/**
 893 * smack_inode_getxattr - Smack check on getxattr
 894 * @dentry: the object
 895 * @name: unused
 896 *
 897 * Returns 0 if access is permitted, an error code otherwise
 898 */
 899static int smack_inode_getxattr(struct dentry *dentry, const char *name)
 900{
 901        struct smk_audit_info ad;
 902
 903        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 904        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 905
 906        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
 907}
 908
 909/**
 910 * smack_inode_removexattr - Smack check on removexattr
 911 * @dentry: the object
 912 * @name: name of the attribute
 913 *
 914 * Removing the Smack attribute requires CAP_MAC_ADMIN
 915 *
 916 * Returns 0 if access is permitted, an error code otherwise
 917 */
 918static int smack_inode_removexattr(struct dentry *dentry, const char *name)
 919{
 920        struct inode_smack *isp;
 921        struct smk_audit_info ad;
 922        int rc = 0;
 923
 924        if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
 925            strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
 926            strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
 927            strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
 928            strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
 929            strcmp(name, XATTR_NAME_SMACKMMAP)) {
 930                if (!smack_privileged(CAP_MAC_ADMIN))
 931                        rc = -EPERM;
 932        } else
 933                rc = cap_inode_removexattr(dentry, name);
 934
 935        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
 936        smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
 937        if (rc == 0)
 938                rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
 939
 940        if (rc == 0) {
 941                isp = dentry->d_inode->i_security;
 942                isp->smk_task = NULL;
 943                isp->smk_mmap = NULL;
 944        }
 945
 946        return rc;
 947}
 948
 949/**
 950 * smack_inode_getsecurity - get smack xattrs
 951 * @inode: the object
 952 * @name: attribute name
 953 * @buffer: where to put the result
 954 * @alloc: unused
 955 *
 956 * Returns the size of the attribute or an error code
 957 */
 958static int smack_inode_getsecurity(const struct inode *inode,
 959                                   const char *name, void **buffer,
 960                                   bool alloc)
 961{
 962        struct socket_smack *ssp;
 963        struct socket *sock;
 964        struct super_block *sbp;
 965        struct inode *ip = (struct inode *)inode;
 966        char *isp;
 967        int ilen;
 968        int rc = 0;
 969
 970        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
 971                isp = smk_of_inode(inode);
 972                ilen = strlen(isp) + 1;
 973                *buffer = isp;
 974                return ilen;
 975        }
 976
 977        /*
 978         * The rest of the Smack xattrs are only on sockets.
 979         */
 980        sbp = ip->i_sb;
 981        if (sbp->s_magic != SOCKFS_MAGIC)
 982                return -EOPNOTSUPP;
 983
 984        sock = SOCKET_I(ip);
 985        if (sock == NULL || sock->sk == NULL)
 986                return -EOPNOTSUPP;
 987
 988        ssp = sock->sk->sk_security;
 989
 990        if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 991                isp = ssp->smk_in;
 992        else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
 993                isp = ssp->smk_out;
 994        else
 995                return -EOPNOTSUPP;
 996
 997        ilen = strlen(isp) + 1;
 998        if (rc == 0) {
 999                *buffer = isp;
1000                rc = ilen;
1001        }
1002
1003        return rc;
1004}
1005
1006
1007/**
1008 * smack_inode_listsecurity - list the Smack attributes
1009 * @inode: the object
1010 * @buffer: where they go
1011 * @buffer_size: size of buffer
1012 *
1013 * Returns 0 on success, -EINVAL otherwise
1014 */
1015static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1016                                    size_t buffer_size)
1017{
1018        int len = strlen(XATTR_NAME_SMACK);
1019
1020        if (buffer != NULL && len <= buffer_size) {
1021                memcpy(buffer, XATTR_NAME_SMACK, len);
1022                return len;
1023        }
1024        return -EINVAL;
1025}
1026
1027/**
1028 * smack_inode_getsecid - Extract inode's security id
1029 * @inode: inode to extract the info from
1030 * @secid: where result will be saved
1031 */
1032static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
1033{
1034        struct inode_smack *isp = inode->i_security;
1035
1036        *secid = smack_to_secid(isp->smk_inode);
1037}
1038
1039/*
1040 * File Hooks
1041 */
1042
1043/**
1044 * smack_file_permission - Smack check on file operations
1045 * @file: unused
1046 * @mask: unused
1047 *
1048 * Returns 0
1049 *
1050 * Should access checks be done on each read or write?
1051 * UNICOS and SELinux say yes.
1052 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1053 *
1054 * I'll say no for now. Smack does not do the frequent
1055 * label changing that SELinux does.
1056 */
1057static int smack_file_permission(struct file *file, int mask)
1058{
1059        return 0;
1060}
1061
1062/**
1063 * smack_file_alloc_security - assign a file security blob
1064 * @file: the object
1065 *
1066 * The security blob for a file is a pointer to the master
1067 * label list, so no allocation is done.
1068 *
1069 * Returns 0
1070 */
1071static int smack_file_alloc_security(struct file *file)
1072{
1073        file->f_security = smk_of_current();
1074        return 0;
1075}
1076
1077/**
1078 * smack_file_free_security - clear a file security blob
1079 * @file: the object
1080 *
1081 * The security blob for a file is a pointer to the master
1082 * label list, so no memory is freed.
1083 */
1084static void smack_file_free_security(struct file *file)
1085{
1086        file->f_security = NULL;
1087}
1088
1089/**
1090 * smack_file_ioctl - Smack check on ioctls
1091 * @file: the object
1092 * @cmd: what to do
1093 * @arg: unused
1094 *
1095 * Relies heavily on the correct use of the ioctl command conventions.
1096 *
1097 * Returns 0 if allowed, error code otherwise
1098 */
1099static int smack_file_ioctl(struct file *file, unsigned int cmd,
1100                            unsigned long arg)
1101{
1102        int rc = 0;
1103        struct smk_audit_info ad;
1104
1105        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1106        smk_ad_setfield_u_fs_path(&ad, file->f_path);
1107
1108        if (_IOC_DIR(cmd) & _IOC_WRITE)
1109                rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1110
1111        if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1112                rc = smk_curacc(file->f_security, MAY_READ, &ad);
1113
1114        return rc;
1115}
1116
1117/**
1118 * smack_file_lock - Smack check on file locking
1119 * @file: the object
1120 * @cmd: unused
1121 *
1122 * Returns 0 if current has write access, error code otherwise
1123 */
1124static int smack_file_lock(struct file *file, unsigned int cmd)
1125{
1126        struct smk_audit_info ad;
1127
1128        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1129        smk_ad_setfield_u_fs_path(&ad, file->f_path);
1130        return smk_curacc(file->f_security, MAY_WRITE, &ad);
1131}
1132
1133/**
1134 * smack_file_fcntl - Smack check on fcntl
1135 * @file: the object
1136 * @cmd: what action to check
1137 * @arg: unused
1138 *
1139 * Generally these operations are harmless.
1140 * File locking operations present an obvious mechanism
1141 * for passing information, so they require write access.
1142 *
1143 * Returns 0 if current has access, error code otherwise
1144 */
1145static int smack_file_fcntl(struct file *file, unsigned int cmd,
1146                            unsigned long arg)
1147{
1148        struct smk_audit_info ad;
1149        int rc = 0;
1150
1151
1152        switch (cmd) {
1153        case F_GETLK:
1154        case F_SETLK:
1155        case F_SETLKW:
1156        case F_SETOWN:
1157        case F_SETSIG:
1158                smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1159                smk_ad_setfield_u_fs_path(&ad, file->f_path);
1160                rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1161                break;
1162        default:
1163                break;
1164        }
1165
1166        return rc;
1167}
1168
1169/**
1170 * smack_mmap_file :
1171 * Check permissions for a mmap operation.  The @file may be NULL, e.g.
1172 * if mapping anonymous memory.
1173 * @file contains the file structure for file to map (may be NULL).
1174 * @reqprot contains the protection requested by the application.
1175 * @prot contains the protection that will be applied by the kernel.
1176 * @flags contains the operational flags.
1177 * Return 0 if permission is granted.
1178 */
1179static int smack_mmap_file(struct file *file,
1180                           unsigned long reqprot, unsigned long prot,
1181                           unsigned long flags)
1182{
1183        struct smack_known *skp;
1184        struct smack_rule *srp;
1185        struct task_smack *tsp;
1186        char *sp;
1187        char *msmack;
1188        char *osmack;
1189        struct inode_smack *isp;
1190        struct dentry *dp;
1191        int may;
1192        int mmay;
1193        int tmay;
1194        int rc;
1195
1196        if (file == NULL || file->f_dentry == NULL)
1197                return 0;
1198
1199        dp = file->f_dentry;
1200
1201        if (dp->d_inode == NULL)
1202                return 0;
1203
1204        isp = dp->d_inode->i_security;
1205        if (isp->smk_mmap == NULL)
1206                return 0;
1207        msmack = isp->smk_mmap;
1208
1209        tsp = current_security();
1210        sp = smk_of_current();
1211        skp = smk_find_entry(sp);
1212        rc = 0;
1213
1214        rcu_read_lock();
1215        /*
1216         * For each Smack rule associated with the subject
1217         * label verify that the SMACK64MMAP also has access
1218         * to that rule's object label.
1219         */
1220        list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1221                osmack = srp->smk_object;
1222                /*
1223                 * Matching labels always allows access.
1224                 */
1225                if (msmack == osmack)
1226                        continue;
1227                /*
1228                 * If there is a matching local rule take
1229                 * that into account as well.
1230                 */
1231                may = smk_access_entry(srp->smk_subject, osmack,
1232                                        &tsp->smk_rules);
1233                if (may == -ENOENT)
1234                        may = srp->smk_access;
1235                else
1236                        may &= srp->smk_access;
1237                /*
1238                 * If may is zero the SMACK64MMAP subject can't
1239                 * possibly have less access.
1240                 */
1241                if (may == 0)
1242                        continue;
1243
1244                /*
1245                 * Fetch the global list entry.
1246                 * If there isn't one a SMACK64MMAP subject
1247                 * can't have as much access as current.
1248                 */
1249                skp = smk_find_entry(msmack);
1250                mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
1251                if (mmay == -ENOENT) {
1252                        rc = -EACCES;
1253                        break;
1254                }
1255                /*
1256                 * If there is a local entry it modifies the
1257                 * potential access, too.
1258                 */
1259                tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1260                if (tmay != -ENOENT)
1261                        mmay &= tmay;
1262
1263                /*
1264                 * If there is any access available to current that is
1265                 * not available to a SMACK64MMAP subject
1266                 * deny access.
1267                 */
1268                if ((may | mmay) != mmay) {
1269                        rc = -EACCES;
1270                        break;
1271                }
1272        }
1273
1274        rcu_read_unlock();
1275
1276        return rc;
1277}
1278
1279/**
1280 * smack_file_set_fowner - set the file security blob value
1281 * @file: object in question
1282 *
1283 * Returns 0
1284 * Further research may be required on this one.
1285 */
1286static int smack_file_set_fowner(struct file *file)
1287{
1288        file->f_security = smk_of_current();
1289        return 0;
1290}
1291
1292/**
1293 * smack_file_send_sigiotask - Smack on sigio
1294 * @tsk: The target task
1295 * @fown: the object the signal come from
1296 * @signum: unused
1297 *
1298 * Allow a privileged task to get signals even if it shouldn't
1299 *
1300 * Returns 0 if a subject with the object's smack could
1301 * write to the task, an error code otherwise.
1302 */
1303static int smack_file_send_sigiotask(struct task_struct *tsk,
1304                                     struct fown_struct *fown, int signum)
1305{
1306        struct file *file;
1307        int rc;
1308        char *tsp = smk_of_task(tsk->cred->security);
1309        struct smk_audit_info ad;
1310
1311        /*
1312         * struct fown_struct is never outside the context of a struct file
1313         */
1314        file = container_of(fown, struct file, f_owner);
1315
1316        /* we don't log here as rc can be overriden */
1317        rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1318        if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1319                rc = 0;
1320
1321        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1322        smk_ad_setfield_u_tsk(&ad, tsk);
1323        smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1324        return rc;
1325}
1326
1327/**
1328 * smack_file_receive - Smack file receive check
1329 * @file: the object
1330 *
1331 * Returns 0 if current has access, error code otherwise
1332 */
1333static int smack_file_receive(struct file *file)
1334{
1335        int may = 0;
1336        struct smk_audit_info ad;
1337
1338        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1339        smk_ad_setfield_u_fs_path(&ad, file->f_path);
1340        /*
1341         * This code relies on bitmasks.
1342         */
1343        if (file->f_mode & FMODE_READ)
1344                may = MAY_READ;
1345        if (file->f_mode & FMODE_WRITE)
1346                may |= MAY_WRITE;
1347
1348        return smk_curacc(file->f_security, may, &ad);
1349}
1350
1351/**
1352 * smack_file_open - Smack dentry open processing
1353 * @file: the object
1354 * @cred: unused
1355 *
1356 * Set the security blob in the file structure.
1357 *
1358 * Returns 0
1359 */
1360static int smack_file_open(struct file *file, const struct cred *cred)
1361{
1362        struct inode_smack *isp = file->f_path.dentry->d_inode->i_security;
1363
1364        file->f_security = isp->smk_inode;
1365
1366        return 0;
1367}
1368
1369/*
1370 * Task hooks
1371 */
1372
1373/**
1374 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1375 * @new: the new credentials
1376 * @gfp: the atomicity of any memory allocations
1377 *
1378 * Prepare a blank set of credentials for modification.  This must allocate all
1379 * the memory the LSM module might require such that cred_transfer() can
1380 * complete without error.
1381 */
1382static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1383{
1384        struct task_smack *tsp;
1385
1386        tsp = new_task_smack(NULL, NULL, gfp);
1387        if (tsp == NULL)
1388                return -ENOMEM;
1389
1390        cred->security = tsp;
1391
1392        return 0;
1393}
1394
1395
1396/**
1397 * smack_cred_free - "free" task-level security credentials
1398 * @cred: the credentials in question
1399 *
1400 */
1401static void smack_cred_free(struct cred *cred)
1402{
1403        struct task_smack *tsp = cred->security;
1404        struct smack_rule *rp;
1405        struct list_head *l;
1406        struct list_head *n;
1407
1408        if (tsp == NULL)
1409                return;
1410        cred->security = NULL;
1411
1412        list_for_each_safe(l, n, &tsp->smk_rules) {
1413                rp = list_entry(l, struct smack_rule, list);
1414                list_del(&rp->list);
1415                kfree(rp);
1416        }
1417        kfree(tsp);
1418}
1419
1420/**
1421 * smack_cred_prepare - prepare new set of credentials for modification
1422 * @new: the new credentials
1423 * @old: the original credentials
1424 * @gfp: the atomicity of any memory allocations
1425 *
1426 * Prepare a new set of credentials for modification.
1427 */
1428static int smack_cred_prepare(struct cred *new, const struct cred *old,
1429                              gfp_t gfp)
1430{
1431        struct task_smack *old_tsp = old->security;
1432        struct task_smack *new_tsp;
1433        int rc;
1434
1435        new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1436        if (new_tsp == NULL)
1437                return -ENOMEM;
1438
1439        rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1440        if (rc != 0)
1441                return rc;
1442
1443        new->security = new_tsp;
1444        return 0;
1445}
1446
1447/**
1448 * smack_cred_transfer - Transfer the old credentials to the new credentials
1449 * @new: the new credentials
1450 * @old: the original credentials
1451 *
1452 * Fill in a set of blank credentials from another set of credentials.
1453 */
1454static void smack_cred_transfer(struct cred *new, const struct cred *old)
1455{
1456        struct task_smack *old_tsp = old->security;
1457        struct task_smack *new_tsp = new->security;
1458
1459        new_tsp->smk_task = old_tsp->smk_task;
1460        new_tsp->smk_forked = old_tsp->smk_task;
1461        mutex_init(&new_tsp->smk_rules_lock);
1462        INIT_LIST_HEAD(&new_tsp->smk_rules);
1463
1464
1465        /* cbs copy rule list */
1466}
1467
1468/**
1469 * smack_kernel_act_as - Set the subjective context in a set of credentials
1470 * @new: points to the set of credentials to be modified.
1471 * @secid: specifies the security ID to be set
1472 *
1473 * Set the security data for a kernel service.
1474 */
1475static int smack_kernel_act_as(struct cred *new, u32 secid)
1476{
1477        struct task_smack *new_tsp = new->security;
1478        char *smack = smack_from_secid(secid);
1479
1480        if (smack == NULL)
1481                return -EINVAL;
1482
1483        new_tsp->smk_task = smack;
1484        return 0;
1485}
1486
1487/**
1488 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1489 * @new: points to the set of credentials to be modified
1490 * @inode: points to the inode to use as a reference
1491 *
1492 * Set the file creation context in a set of credentials to the same
1493 * as the objective context of the specified inode
1494 */
1495static int smack_kernel_create_files_as(struct cred *new,
1496                                        struct inode *inode)
1497{
1498        struct inode_smack *isp = inode->i_security;
1499        struct task_smack *tsp = new->security;
1500
1501        tsp->smk_forked = isp->smk_inode;
1502        tsp->smk_task = isp->smk_inode;
1503        return 0;
1504}
1505
1506/**
1507 * smk_curacc_on_task - helper to log task related access
1508 * @p: the task object
1509 * @access: the access requested
1510 * @caller: name of the calling function for audit
1511 *
1512 * Return 0 if access is permitted
1513 */
1514static int smk_curacc_on_task(struct task_struct *p, int access,
1515                                const char *caller)
1516{
1517        struct smk_audit_info ad;
1518
1519        smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
1520        smk_ad_setfield_u_tsk(&ad, p);
1521        return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1522}
1523
1524/**
1525 * smack_task_setpgid - Smack check on setting pgid
1526 * @p: the task object
1527 * @pgid: unused
1528 *
1529 * Return 0 if write access is permitted
1530 */
1531static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1532{
1533        return smk_curacc_on_task(p, MAY_WRITE, __func__);
1534}
1535
1536/**
1537 * smack_task_getpgid - Smack access check for getpgid
1538 * @p: the object task
1539 *
1540 * Returns 0 if current can read the object task, error code otherwise
1541 */
1542static int smack_task_getpgid(struct task_struct *p)
1543{
1544        return smk_curacc_on_task(p, MAY_READ, __func__);
1545}
1546
1547/**
1548 * smack_task_getsid - Smack access check for getsid
1549 * @p: the object task
1550 *
1551 * Returns 0 if current can read the object task, error code otherwise
1552 */
1553static int smack_task_getsid(struct task_struct *p)
1554{
1555        return smk_curacc_on_task(p, MAY_READ, __func__);
1556}
1557
1558/**
1559 * smack_task_getsecid - get the secid of the task
1560 * @p: the object task
1561 * @secid: where to put the result
1562 *
1563 * Sets the secid to contain a u32 version of the smack label.
1564 */
1565static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1566{
1567        *secid = smack_to_secid(smk_of_task(task_security(p)));
1568}
1569
1570/**
1571 * smack_task_setnice - Smack check on setting nice
1572 * @p: the task object
1573 * @nice: unused
1574 *
1575 * Return 0 if write access is permitted
1576 */
1577static int smack_task_setnice(struct task_struct *p, int nice)
1578{
1579        int rc;
1580
1581        rc = cap_task_setnice(p, nice);
1582        if (rc == 0)
1583                rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1584        return rc;
1585}
1586
1587/**
1588 * smack_task_setioprio - Smack check on setting ioprio
1589 * @p: the task object
1590 * @ioprio: unused
1591 *
1592 * Return 0 if write access is permitted
1593 */
1594static int smack_task_setioprio(struct task_struct *p, int ioprio)
1595{
1596        int rc;
1597
1598        rc = cap_task_setioprio(p, ioprio);
1599        if (rc == 0)
1600                rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1601        return rc;
1602}
1603
1604/**
1605 * smack_task_getioprio - Smack check on reading ioprio
1606 * @p: the task object
1607 *
1608 * Return 0 if read access is permitted
1609 */
1610static int smack_task_getioprio(struct task_struct *p)
1611{
1612        return smk_curacc_on_task(p, MAY_READ, __func__);
1613}
1614
1615/**
1616 * smack_task_setscheduler - Smack check on setting scheduler
1617 * @p: the task object
1618 * @policy: unused
1619 * @lp: unused
1620 *
1621 * Return 0 if read access is permitted
1622 */
1623static int smack_task_setscheduler(struct task_struct *p)
1624{
1625        int rc;
1626
1627        rc = cap_task_setscheduler(p);
1628        if (rc == 0)
1629                rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1630        return rc;
1631}
1632
1633/**
1634 * smack_task_getscheduler - Smack check on reading scheduler
1635 * @p: the task object
1636 *
1637 * Return 0 if read access is permitted
1638 */
1639static int smack_task_getscheduler(struct task_struct *p)
1640{
1641        return smk_curacc_on_task(p, MAY_READ, __func__);
1642}
1643
1644/**
1645 * smack_task_movememory - Smack check on moving memory
1646 * @p: the task object
1647 *
1648 * Return 0 if write access is permitted
1649 */
1650static int smack_task_movememory(struct task_struct *p)
1651{
1652        return smk_curacc_on_task(p, MAY_WRITE, __func__);
1653}
1654
1655/**
1656 * smack_task_kill - Smack check on signal delivery
1657 * @p: the task object
1658 * @info: unused
1659 * @sig: unused
1660 * @secid: identifies the smack to use in lieu of current's
1661 *
1662 * Return 0 if write access is permitted
1663 *
1664 * The secid behavior is an artifact of an SELinux hack
1665 * in the USB code. Someday it may go away.
1666 */
1667static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1668                           int sig, u32 secid)
1669{
1670        struct smk_audit_info ad;
1671
1672        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1673        smk_ad_setfield_u_tsk(&ad, p);
1674        /*
1675         * Sending a signal requires that the sender
1676         * can write the receiver.
1677         */
1678        if (secid == 0)
1679                return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1680                                  &ad);
1681        /*
1682         * If the secid isn't 0 we're dealing with some USB IO
1683         * specific behavior. This is not clean. For one thing
1684         * we can't take privilege into account.
1685         */
1686        return smk_access(smack_from_secid(secid),
1687                          smk_of_task(task_security(p)), MAY_WRITE, &ad);
1688}
1689
1690/**
1691 * smack_task_wait - Smack access check for waiting
1692 * @p: task to wait for
1693 *
1694 * Returns 0 if current can wait for p, error code otherwise
1695 */
1696static int smack_task_wait(struct task_struct *p)
1697{
1698        struct smk_audit_info ad;
1699        char *sp = smk_of_current();
1700        char *tsp = smk_of_forked(task_security(p));
1701        int rc;
1702
1703        /* we don't log here, we can be overriden */
1704        rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1705        if (rc == 0)
1706                goto out_log;
1707
1708        /*
1709         * Allow the operation to succeed if either task
1710         * has privilege to perform operations that might
1711         * account for the smack labels having gotten to
1712         * be different in the first place.
1713         *
1714         * This breaks the strict subject/object access
1715         * control ideal, taking the object's privilege
1716         * state into account in the decision as well as
1717         * the smack value.
1718         */
1719        if (smack_privileged(CAP_MAC_OVERRIDE) ||
1720            has_capability(p, CAP_MAC_OVERRIDE))
1721                rc = 0;
1722        /* we log only if we didn't get overriden */
1723 out_log:
1724        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1725        smk_ad_setfield_u_tsk(&ad, p);
1726        smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1727        return rc;
1728}
1729
1730/**
1731 * smack_task_to_inode - copy task smack into the inode blob
1732 * @p: task to copy from
1733 * @inode: inode to copy to
1734 *
1735 * Sets the smack pointer in the inode security blob
1736 */
1737static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1738{
1739        struct inode_smack *isp = inode->i_security;
1740        isp->smk_inode = smk_of_task(task_security(p));
1741}
1742
1743/*
1744 * Socket hooks.
1745 */
1746
1747/**
1748 * smack_sk_alloc_security - Allocate a socket blob
1749 * @sk: the socket
1750 * @family: unused
1751 * @gfp_flags: memory allocation flags
1752 *
1753 * Assign Smack pointers to current
1754 *
1755 * Returns 0 on success, -ENOMEM is there's no memory
1756 */
1757static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1758{
1759        char *csp = smk_of_current();
1760        struct socket_smack *ssp;
1761
1762        ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1763        if (ssp == NULL)
1764                return -ENOMEM;
1765
1766        ssp->smk_in = csp;
1767        ssp->smk_out = csp;
1768        ssp->smk_packet = NULL;
1769
1770        sk->sk_security = ssp;
1771
1772        return 0;
1773}
1774
1775/**
1776 * smack_sk_free_security - Free a socket blob
1777 * @sk: the socket
1778 *
1779 * Clears the blob pointer
1780 */
1781static void smack_sk_free_security(struct sock *sk)
1782{
1783        kfree(sk->sk_security);
1784}
1785
1786/**
1787* smack_host_label - check host based restrictions
1788* @sip: the object end
1789*
1790* looks for host based access restrictions
1791*
1792* This version will only be appropriate for really small sets of single label
1793* hosts.  The caller is responsible for ensuring that the RCU read lock is
1794* taken before calling this function.
1795*
1796* Returns the label of the far end or NULL if it's not special.
1797*/
1798static char *smack_host_label(struct sockaddr_in *sip)
1799{
1800        struct smk_netlbladdr *snp;
1801        struct in_addr *siap = &sip->sin_addr;
1802
1803        if (siap->s_addr == 0)
1804                return NULL;
1805
1806        list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1807                /*
1808                * we break after finding the first match because
1809                * the list is sorted from longest to shortest mask
1810                * so we have found the most specific match
1811                */
1812                if ((&snp->smk_host.sin_addr)->s_addr ==
1813                    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1814                        /* we have found the special CIPSO option */
1815                        if (snp->smk_label == smack_cipso_option)
1816                                return NULL;
1817                        return snp->smk_label;
1818                }
1819
1820        return NULL;
1821}
1822
1823/**
1824 * smack_netlabel - Set the secattr on a socket
1825 * @sk: the socket
1826 * @labeled: socket label scheme
1827 *
1828 * Convert the outbound smack value (smk_out) to a
1829 * secattr and attach it to the socket.
1830 *
1831 * Returns 0 on success or an error code
1832 */
1833static int smack_netlabel(struct sock *sk, int labeled)
1834{
1835        struct smack_known *skp;
1836        struct socket_smack *ssp = sk->sk_security;
1837        int rc = 0;
1838
1839        /*
1840         * Usually the netlabel code will handle changing the
1841         * packet labeling based on the label.
1842         * The case of a single label host is different, because
1843         * a single label host should never get a labeled packet
1844         * even though the label is usually associated with a packet
1845         * label.
1846         */
1847        local_bh_disable();
1848        bh_lock_sock_nested(sk);
1849
1850        if (ssp->smk_out == smack_net_ambient ||
1851            labeled == SMACK_UNLABELED_SOCKET)
1852                netlbl_sock_delattr(sk);
1853        else {
1854                skp = smk_find_entry(ssp->smk_out);
1855                rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
1856        }
1857
1858        bh_unlock_sock(sk);
1859        local_bh_enable();
1860
1861        return rc;
1862}
1863
1864/**
1865 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1866 * @sk: the socket
1867 * @sap: the destination address
1868 *
1869 * Set the correct secattr for the given socket based on the destination
1870 * address and perform any outbound access checks needed.
1871 *
1872 * Returns 0 on success or an error code.
1873 *
1874 */
1875static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1876{
1877        int rc;
1878        int sk_lbl;
1879        char *hostsp;
1880        struct socket_smack *ssp = sk->sk_security;
1881        struct smk_audit_info ad;
1882
1883        rcu_read_lock();
1884        hostsp = smack_host_label(sap);
1885        if (hostsp != NULL) {
1886#ifdef CONFIG_AUDIT
1887                struct lsm_network_audit net;
1888
1889                smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
1890                ad.a.u.net->family = sap->sin_family;
1891                ad.a.u.net->dport = sap->sin_port;
1892                ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
1893#endif
1894                sk_lbl = SMACK_UNLABELED_SOCKET;
1895                rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1896        } else {
1897                sk_lbl = SMACK_CIPSO_SOCKET;
1898                rc = 0;
1899        }
1900        rcu_read_unlock();
1901        if (rc != 0)
1902                return rc;
1903
1904        return smack_netlabel(sk, sk_lbl);
1905}
1906
1907/**
1908 * smack_inode_setsecurity - set smack xattrs
1909 * @inode: the object
1910 * @name: attribute name
1911 * @value: attribute value
1912 * @size: size of the attribute
1913 * @flags: unused
1914 *
1915 * Sets the named attribute in the appropriate blob
1916 *
1917 * Returns 0 on success, or an error code
1918 */
1919static int smack_inode_setsecurity(struct inode *inode, const char *name,
1920                                   const void *value, size_t size, int flags)
1921{
1922        char *sp;
1923        struct inode_smack *nsp = inode->i_security;
1924        struct socket_smack *ssp;
1925        struct socket *sock;
1926        int rc = 0;
1927
1928        if (value == NULL || size > SMK_LONGLABEL || size == 0)
1929                return -EACCES;
1930
1931        sp = smk_import(value, size);
1932        if (sp == NULL)
1933                return -EINVAL;
1934
1935        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1936                nsp->smk_inode = sp;
1937                nsp->smk_flags |= SMK_INODE_INSTANT;
1938                return 0;
1939        }
1940        /*
1941         * The rest of the Smack xattrs are only on sockets.
1942         */
1943        if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1944                return -EOPNOTSUPP;
1945
1946        sock = SOCKET_I(inode);
1947        if (sock == NULL || sock->sk == NULL)
1948                return -EOPNOTSUPP;
1949
1950        ssp = sock->sk->sk_security;
1951
1952        if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1953                ssp->smk_in = sp;
1954        else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1955                ssp->smk_out = sp;
1956                if (sock->sk->sk_family != PF_UNIX) {
1957                        rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1958                        if (rc != 0)
1959                                printk(KERN_WARNING
1960                                        "Smack: \"%s\" netlbl error %d.\n",
1961                                        __func__, -rc);
1962                }
1963        } else
1964                return -EOPNOTSUPP;
1965
1966        return 0;
1967}
1968
1969/**
1970 * smack_socket_post_create - finish socket setup
1971 * @sock: the socket
1972 * @family: protocol family
1973 * @type: unused
1974 * @protocol: unused
1975 * @kern: unused
1976 *
1977 * Sets the netlabel information on the socket
1978 *
1979 * Returns 0 on success, and error code otherwise
1980 */
1981static int smack_socket_post_create(struct socket *sock, int family,
1982                                    int type, int protocol, int kern)
1983{
1984        if (family != PF_INET || sock->sk == NULL)
1985                return 0;
1986        /*
1987         * Set the outbound netlbl.
1988         */
1989        return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1990}
1991
1992/**
1993 * smack_socket_connect - connect access check
1994 * @sock: the socket
1995 * @sap: the other end
1996 * @addrlen: size of sap
1997 *
1998 * Verifies that a connection may be possible
1999 *
2000 * Returns 0 on success, and error code otherwise
2001 */
2002static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2003                                int addrlen)
2004{
2005        if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2006                return 0;
2007        if (addrlen < sizeof(struct sockaddr_in))
2008                return -EINVAL;
2009
2010        return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2011}
2012
2013/**
2014 * smack_flags_to_may - convert S_ to MAY_ values
2015 * @flags: the S_ value
2016 *
2017 * Returns the equivalent MAY_ value
2018 */
2019static int smack_flags_to_may(int flags)
2020{
2021        int may = 0;
2022
2023        if (flags & S_IRUGO)
2024                may |= MAY_READ;
2025        if (flags & S_IWUGO)
2026                may |= MAY_WRITE;
2027        if (flags & S_IXUGO)
2028                may |= MAY_EXEC;
2029
2030        return may;
2031}
2032
2033/**
2034 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2035 * @msg: the object
2036 *
2037 * Returns 0
2038 */
2039static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2040{
2041        msg->security = smk_of_current();
2042        return 0;
2043}
2044
2045/**
2046 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2047 * @msg: the object
2048 *
2049 * Clears the blob pointer
2050 */
2051static void smack_msg_msg_free_security(struct msg_msg *msg)
2052{
2053        msg->security = NULL;
2054}
2055
2056/**
2057 * smack_of_shm - the smack pointer for the shm
2058 * @shp: the object
2059 *
2060 * Returns a pointer to the smack value
2061 */
2062static char *smack_of_shm(struct shmid_kernel *shp)
2063{
2064        return (char *)shp->shm_perm.security;
2065}
2066
2067/**
2068 * smack_shm_alloc_security - Set the security blob for shm
2069 * @shp: the object
2070 *
2071 * Returns 0
2072 */
2073static int smack_shm_alloc_security(struct shmid_kernel *shp)
2074{
2075        struct kern_ipc_perm *isp = &shp->shm_perm;
2076
2077        isp->security = smk_of_current();
2078        return 0;
2079}
2080
2081/**
2082 * smack_shm_free_security - Clear the security blob for shm
2083 * @shp: the object
2084 *
2085 * Clears the blob pointer
2086 */
2087static void smack_shm_free_security(struct shmid_kernel *shp)
2088{
2089        struct kern_ipc_perm *isp = &shp->shm_perm;
2090
2091        isp->security = NULL;
2092}
2093
2094/**
2095 * smk_curacc_shm : check if current has access on shm
2096 * @shp : the object
2097 * @access : access requested
2098 *
2099 * Returns 0 if current has the requested access, error code otherwise
2100 */
2101static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2102{
2103        char *ssp = smack_of_shm(shp);
2104        struct smk_audit_info ad;
2105
2106#ifdef CONFIG_AUDIT
2107        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2108        ad.a.u.ipc_id = shp->shm_perm.id;
2109#endif
2110        return smk_curacc(ssp, access, &ad);
2111}
2112
2113/**
2114 * smack_shm_associate - Smack access check for shm
2115 * @shp: the object
2116 * @shmflg: access requested
2117 *
2118 * Returns 0 if current has the requested access, error code otherwise
2119 */
2120static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2121{
2122        int may;
2123
2124        may = smack_flags_to_may(shmflg);
2125        return smk_curacc_shm(shp, may);
2126}
2127
2128/**
2129 * smack_shm_shmctl - Smack access check for shm
2130 * @shp: the object
2131 * @cmd: what it wants to do
2132 *
2133 * Returns 0 if current has the requested access, error code otherwise
2134 */
2135static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2136{
2137        int may;
2138
2139        switch (cmd) {
2140        case IPC_STAT:
2141        case SHM_STAT:
2142                may = MAY_READ;
2143                break;
2144        case IPC_SET:
2145        case SHM_LOCK:
2146        case SHM_UNLOCK:
2147        case IPC_RMID:
2148                may = MAY_READWRITE;
2149                break;
2150        case IPC_INFO:
2151        case SHM_INFO:
2152                /*
2153                 * System level information.
2154                 */
2155                return 0;
2156        default:
2157                return -EINVAL;
2158        }
2159        return smk_curacc_shm(shp, may);
2160}
2161
2162/**
2163 * smack_shm_shmat - Smack access for shmat
2164 * @shp: the object
2165 * @shmaddr: unused
2166 * @shmflg: access requested
2167 *
2168 * Returns 0 if current has the requested access, error code otherwise
2169 */
2170static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2171                           int shmflg)
2172{
2173        int may;
2174
2175        may = smack_flags_to_may(shmflg);
2176        return smk_curacc_shm(shp, may);
2177}
2178
2179/**
2180 * smack_of_sem - the smack pointer for the sem
2181 * @sma: the object
2182 *
2183 * Returns a pointer to the smack value
2184 */
2185static char *smack_of_sem(struct sem_array *sma)
2186{
2187        return (char *)sma->sem_perm.security;
2188}
2189
2190/**
2191 * smack_sem_alloc_security - Set the security blob for sem
2192 * @sma: the object
2193 *
2194 * Returns 0
2195 */
2196static int smack_sem_alloc_security(struct sem_array *sma)
2197{
2198        struct kern_ipc_perm *isp = &sma->sem_perm;
2199
2200        isp->security = smk_of_current();
2201        return 0;
2202}
2203
2204/**
2205 * smack_sem_free_security - Clear the security blob for sem
2206 * @sma: the object
2207 *
2208 * Clears the blob pointer
2209 */
2210static void smack_sem_free_security(struct sem_array *sma)
2211{
2212        struct kern_ipc_perm *isp = &sma->sem_perm;
2213
2214        isp->security = NULL;
2215}
2216
2217/**
2218 * smk_curacc_sem : check if current has access on sem
2219 * @sma : the object
2220 * @access : access requested
2221 *
2222 * Returns 0 if current has the requested access, error code otherwise
2223 */
2224static int smk_curacc_sem(struct sem_array *sma, int access)
2225{
2226        char *ssp = smack_of_sem(sma);
2227        struct smk_audit_info ad;
2228
2229#ifdef CONFIG_AUDIT
2230        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2231        ad.a.u.ipc_id = sma->sem_perm.id;
2232#endif
2233        return smk_curacc(ssp, access, &ad);
2234}
2235
2236/**
2237 * smack_sem_associate - Smack access check for sem
2238 * @sma: the object
2239 * @semflg: access requested
2240 *
2241 * Returns 0 if current has the requested access, error code otherwise
2242 */
2243static int smack_sem_associate(struct sem_array *sma, int semflg)
2244{
2245        int may;
2246
2247        may = smack_flags_to_may(semflg);
2248        return smk_curacc_sem(sma, may);
2249}
2250
2251/**
2252 * smack_sem_shmctl - Smack access check for sem
2253 * @sma: the object
2254 * @cmd: what it wants to do
2255 *
2256 * Returns 0 if current has the requested access, error code otherwise
2257 */
2258static int smack_sem_semctl(struct sem_array *sma, int cmd)
2259{
2260        int may;
2261
2262        switch (cmd) {
2263        case GETPID:
2264        case GETNCNT:
2265        case GETZCNT:
2266        case GETVAL:
2267        case GETALL:
2268        case IPC_STAT:
2269        case SEM_STAT:
2270                may = MAY_READ;
2271                break;
2272        case SETVAL:
2273        case SETALL:
2274        case IPC_RMID:
2275        case IPC_SET:
2276                may = MAY_READWRITE;
2277                break;
2278        case IPC_INFO:
2279        case SEM_INFO:
2280                /*
2281                 * System level information
2282                 */
2283                return 0;
2284        default:
2285                return -EINVAL;
2286        }
2287
2288        return smk_curacc_sem(sma, may);
2289}
2290
2291/**
2292 * smack_sem_semop - Smack checks of semaphore operations
2293 * @sma: the object
2294 * @sops: unused
2295 * @nsops: unused
2296 * @alter: unused
2297 *
2298 * Treated as read and write in all cases.
2299 *
2300 * Returns 0 if access is allowed, error code otherwise
2301 */
2302static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2303                           unsigned nsops, int alter)
2304{
2305        return smk_curacc_sem(sma, MAY_READWRITE);
2306}
2307
2308/**
2309 * smack_msg_alloc_security - Set the security blob for msg
2310 * @msq: the object
2311 *
2312 * Returns 0
2313 */
2314static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2315{
2316        struct kern_ipc_perm *kisp = &msq->q_perm;
2317
2318        kisp->security = smk_of_current();
2319        return 0;
2320}
2321
2322/**
2323 * smack_msg_free_security - Clear the security blob for msg
2324 * @msq: the object
2325 *
2326 * Clears the blob pointer
2327 */
2328static void smack_msg_queue_free_security(struct msg_queue *msq)
2329{
2330        struct kern_ipc_perm *kisp = &msq->q_perm;
2331
2332        kisp->security = NULL;
2333}
2334
2335/**
2336 * smack_of_msq - the smack pointer for the msq
2337 * @msq: the object
2338 *
2339 * Returns a pointer to the smack value
2340 */
2341static char *smack_of_msq(struct msg_queue *msq)
2342{
2343        return (char *)msq->q_perm.security;
2344}
2345
2346/**
2347 * smk_curacc_msq : helper to check if current has access on msq
2348 * @msq : the msq
2349 * @access : access requested
2350 *
2351 * return 0 if current has access, error otherwise
2352 */
2353static int smk_curacc_msq(struct msg_queue *msq, int access)
2354{
2355        char *msp = smack_of_msq(msq);
2356        struct smk_audit_info ad;
2357
2358#ifdef CONFIG_AUDIT
2359        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2360        ad.a.u.ipc_id = msq->q_perm.id;
2361#endif
2362        return smk_curacc(msp, access, &ad);
2363}
2364
2365/**
2366 * smack_msg_queue_associate - Smack access check for msg_queue
2367 * @msq: the object
2368 * @msqflg: access requested
2369 *
2370 * Returns 0 if current has the requested access, error code otherwise
2371 */
2372static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2373{
2374        int may;
2375
2376        may = smack_flags_to_may(msqflg);
2377        return smk_curacc_msq(msq, may);
2378}
2379
2380/**
2381 * smack_msg_queue_msgctl - Smack access check for msg_queue
2382 * @msq: the object
2383 * @cmd: what it wants to do
2384 *
2385 * Returns 0 if current has the requested access, error code otherwise
2386 */
2387static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2388{
2389        int may;
2390
2391        switch (cmd) {
2392        case IPC_STAT:
2393        case MSG_STAT:
2394                may = MAY_READ;
2395                break;
2396        case IPC_SET:
2397        case IPC_RMID:
2398                may = MAY_READWRITE;
2399                break;
2400        case IPC_INFO:
2401        case MSG_INFO:
2402                /*
2403                 * System level information
2404                 */
2405                return 0;
2406        default:
2407                return -EINVAL;
2408        }
2409
2410        return smk_curacc_msq(msq, may);
2411}
2412
2413/**
2414 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2415 * @msq: the object
2416 * @msg: unused
2417 * @msqflg: access requested
2418 *
2419 * Returns 0 if current has the requested access, error code otherwise
2420 */
2421static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2422                                  int msqflg)
2423{
2424        int may;
2425
2426        may = smack_flags_to_may(msqflg);
2427        return smk_curacc_msq(msq, may);
2428}
2429
2430/**
2431 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2432 * @msq: the object
2433 * @msg: unused
2434 * @target: unused
2435 * @type: unused
2436 * @mode: unused
2437 *
2438 * Returns 0 if current has read and write access, error code otherwise
2439 */
2440static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2441                        struct task_struct *target, long type, int mode)
2442{
2443        return smk_curacc_msq(msq, MAY_READWRITE);
2444}
2445
2446/**
2447 * smack_ipc_permission - Smack access for ipc_permission()
2448 * @ipp: the object permissions
2449 * @flag: access requested
2450 *
2451 * Returns 0 if current has read and write access, error code otherwise
2452 */
2453static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2454{
2455        char *isp = ipp->security;
2456        int may = smack_flags_to_may(flag);
2457        struct smk_audit_info ad;
2458
2459#ifdef CONFIG_AUDIT
2460        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2461        ad.a.u.ipc_id = ipp->id;
2462#endif
2463        return smk_curacc(isp, may, &ad);
2464}
2465
2466/**
2467 * smack_ipc_getsecid - Extract smack security id
2468 * @ipp: the object permissions
2469 * @secid: where result will be saved
2470 */
2471static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2472{
2473        char *smack = ipp->security;
2474
2475        *secid = smack_to_secid(smack);
2476}
2477
2478/**
2479 * smack_d_instantiate - Make sure the blob is correct on an inode
2480 * @opt_dentry: dentry where inode will be attached
2481 * @inode: the object
2482 *
2483 * Set the inode's security blob if it hasn't been done already.
2484 */
2485static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2486{
2487        struct super_block *sbp;
2488        struct superblock_smack *sbsp;
2489        struct inode_smack *isp;
2490        char *csp = smk_of_current();
2491        char *fetched;
2492        char *final;
2493        char trattr[TRANS_TRUE_SIZE];
2494        int transflag = 0;
2495        int rc;
2496        struct dentry *dp;
2497
2498        if (inode == NULL)
2499                return;
2500
2501        isp = inode->i_security;
2502
2503        mutex_lock(&isp->smk_lock);
2504        /*
2505         * If the inode is already instantiated
2506         * take the quick way out
2507         */
2508        if (isp->smk_flags & SMK_INODE_INSTANT)
2509                goto unlockandout;
2510
2511        sbp = inode->i_sb;
2512        sbsp = sbp->s_security;
2513        /*
2514         * We're going to use the superblock default label
2515         * if there's no label on the file.
2516         */
2517        final = sbsp->smk_default;
2518
2519        /*
2520         * If this is the root inode the superblock
2521         * may be in the process of initialization.
2522         * If that is the case use the root value out
2523         * of the superblock.
2524         */
2525        if (opt_dentry->d_parent == opt_dentry) {
2526                isp->smk_inode = sbsp->smk_root;
2527                isp->smk_flags |= SMK_INODE_INSTANT;
2528                goto unlockandout;
2529        }
2530
2531        /*
2532         * This is pretty hackish.
2533         * Casey says that we shouldn't have to do
2534         * file system specific code, but it does help
2535         * with keeping it simple.
2536         */
2537        switch (sbp->s_magic) {
2538        case SMACK_MAGIC:
2539                /*
2540                 * Casey says that it's a little embarrassing
2541                 * that the smack file system doesn't do
2542                 * extended attributes.
2543                 */
2544                final = smack_known_star.smk_known;
2545                break;
2546        case PIPEFS_MAGIC:
2547                /*
2548                 * Casey says pipes are easy (?)
2549                 */
2550                final = smack_known_star.smk_known;
2551                break;
2552        case DEVPTS_SUPER_MAGIC:
2553                /*
2554                 * devpts seems content with the label of the task.
2555                 * Programs that change smack have to treat the
2556                 * pty with respect.
2557                 */
2558                final = csp;
2559                break;
2560        case SOCKFS_MAGIC:
2561                /*
2562                 * Socket access is controlled by the socket
2563                 * structures associated with the task involved.
2564                 */
2565                final = smack_known_star.smk_known;
2566                break;
2567        case PROC_SUPER_MAGIC:
2568                /*
2569                 * Casey says procfs appears not to care.
2570                 * The superblock default suffices.
2571                 */
2572                break;
2573        case TMPFS_MAGIC:
2574                /*
2575                 * Device labels should come from the filesystem,
2576                 * but watch out, because they're volitile,
2577                 * getting recreated on every reboot.
2578                 */
2579                final = smack_known_star.smk_known;
2580                /*
2581                 * No break.
2582                 *
2583                 * If a smack value has been set we want to use it,
2584                 * but since tmpfs isn't giving us the opportunity
2585                 * to set mount options simulate setting the
2586                 * superblock default.
2587                 */
2588        default:
2589                /*
2590                 * This isn't an understood special case.
2591                 * Get the value from the xattr.
2592                 */
2593
2594                /*
2595                 * UNIX domain sockets use lower level socket data.
2596                 */
2597                if (S_ISSOCK(inode->i_mode)) {
2598                        final = smack_known_star.smk_known;
2599                        break;
2600                }
2601                /*
2602                 * No xattr support means, alas, no SMACK label.
2603                 * Use the aforeapplied default.
2604                 * It would be curious if the label of the task
2605                 * does not match that assigned.
2606                 */
2607                if (inode->i_op->getxattr == NULL)
2608                        break;
2609                /*
2610                 * Get the dentry for xattr.
2611                 */
2612                dp = dget(opt_dentry);
2613                fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2614                if (fetched != NULL)
2615                        final = fetched;
2616
2617                /*
2618                 * Transmuting directory
2619                 */
2620                if (S_ISDIR(inode->i_mode)) {
2621                        /*
2622                         * If this is a new directory and the label was
2623                         * transmuted when the inode was initialized
2624                         * set the transmute attribute on the directory
2625                         * and mark the inode.
2626                         *
2627                         * If there is a transmute attribute on the
2628                         * directory mark the inode.
2629                         */
2630                        if (isp->smk_flags & SMK_INODE_CHANGED) {
2631                                isp->smk_flags &= ~SMK_INODE_CHANGED;
2632                                rc = inode->i_op->setxattr(dp,
2633                                        XATTR_NAME_SMACKTRANSMUTE,
2634                                        TRANS_TRUE, TRANS_TRUE_SIZE,
2635                                        0);
2636                        } else {
2637                                rc = inode->i_op->getxattr(dp,
2638                                        XATTR_NAME_SMACKTRANSMUTE, trattr,
2639                                        TRANS_TRUE_SIZE);
2640                                if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
2641                                                       TRANS_TRUE_SIZE) != 0)
2642                                        rc = -EINVAL;
2643                        }
2644                        if (rc >= 0)
2645                                transflag = SMK_INODE_TRANSMUTE;
2646                }
2647                isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2648                isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2649
2650                dput(dp);
2651                break;
2652        }
2653
2654        if (final == NULL)
2655                isp->smk_inode = csp;
2656        else
2657                isp->smk_inode = final;
2658
2659        isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2660
2661unlockandout:
2662        mutex_unlock(&isp->smk_lock);
2663        return;
2664}
2665
2666/**
2667 * smack_getprocattr - Smack process attribute access
2668 * @p: the object task
2669 * @name: the name of the attribute in /proc/.../attr
2670 * @value: where to put the result
2671 *
2672 * Places a copy of the task Smack into value
2673 *
2674 * Returns the length of the smack label or an error code
2675 */
2676static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2677{
2678        char *cp;
2679        int slen;
2680
2681        if (strcmp(name, "current") != 0)
2682                return -EINVAL;
2683
2684        cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2685        if (cp == NULL)
2686                return -ENOMEM;
2687
2688        slen = strlen(cp);
2689        *value = cp;
2690        return slen;
2691}
2692
2693/**
2694 * smack_setprocattr - Smack process attribute setting
2695 * @p: the object task
2696 * @name: the name of the attribute in /proc/.../attr
2697 * @value: the value to set
2698 * @size: the size of the value
2699 *
2700 * Sets the Smack value of the task. Only setting self
2701 * is permitted and only with privilege
2702 *
2703 * Returns the length of the smack label or an error code
2704 */
2705static int smack_setprocattr(struct task_struct *p, char *name,
2706                             void *value, size_t size)
2707{
2708        int rc;
2709        struct task_smack *tsp;
2710        struct task_smack *oldtsp;
2711        struct cred *new;
2712        char *newsmack;
2713
2714        /*
2715         * Changing another process' Smack value is too dangerous
2716         * and supports no sane use case.
2717         */
2718        if (p != current)
2719                return -EPERM;
2720
2721        if (!smack_privileged(CAP_MAC_ADMIN))
2722                return -EPERM;
2723
2724        if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
2725                return -EINVAL;
2726
2727        if (strcmp(name, "current") != 0)
2728                return -EINVAL;
2729
2730        newsmack = smk_import(value, size);
2731        if (newsmack == NULL)
2732                return -EINVAL;
2733
2734        /*
2735         * No process is ever allowed the web ("@") label.
2736         */
2737        if (newsmack == smack_known_web.smk_known)
2738                return -EPERM;
2739
2740        oldtsp = p->cred->security;
2741        new = prepare_creds();
2742        if (new == NULL)
2743                return -ENOMEM;
2744
2745        tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2746        if (tsp == NULL) {
2747                kfree(new);
2748                return -ENOMEM;
2749        }
2750        rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2751        if (rc != 0)
2752                return rc;
2753
2754        new->security = tsp;
2755        commit_creds(new);
2756        return size;
2757}
2758
2759/**
2760 * smack_unix_stream_connect - Smack access on UDS
2761 * @sock: one sock
2762 * @other: the other sock
2763 * @newsk: unused
2764 *
2765 * Return 0 if a subject with the smack of sock could access
2766 * an object with the smack of other, otherwise an error code
2767 */
2768static int smack_unix_stream_connect(struct sock *sock,
2769                                     struct sock *other, struct sock *newsk)
2770{
2771        struct socket_smack *ssp = sock->sk_security;
2772        struct socket_smack *osp = other->sk_security;
2773        struct socket_smack *nsp = newsk->sk_security;
2774        struct smk_audit_info ad;
2775        int rc = 0;
2776
2777#ifdef CONFIG_AUDIT
2778        struct lsm_network_audit net;
2779
2780        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2781        smk_ad_setfield_u_net_sk(&ad, other);
2782#endif
2783
2784        if (!smack_privileged(CAP_MAC_OVERRIDE))
2785                rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2786
2787        /*
2788         * Cross reference the peer labels for SO_PEERSEC.
2789         */
2790        if (rc == 0) {
2791                nsp->smk_packet = ssp->smk_out;
2792                ssp->smk_packet = osp->smk_out;
2793        }
2794
2795        return rc;
2796}
2797
2798/**
2799 * smack_unix_may_send - Smack access on UDS
2800 * @sock: one socket
2801 * @other: the other socket
2802 *
2803 * Return 0 if a subject with the smack of sock could access
2804 * an object with the smack of other, otherwise an error code
2805 */
2806static int smack_unix_may_send(struct socket *sock, struct socket *other)
2807{
2808        struct socket_smack *ssp = sock->sk->sk_security;
2809        struct socket_smack *osp = other->sk->sk_security;
2810        struct smk_audit_info ad;
2811        int rc = 0;
2812
2813#ifdef CONFIG_AUDIT
2814        struct lsm_network_audit net;
2815
2816        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2817        smk_ad_setfield_u_net_sk(&ad, other->sk);
2818#endif
2819
2820        if (!smack_privileged(CAP_MAC_OVERRIDE))
2821                rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2822
2823        return rc;
2824}
2825
2826/**
2827 * smack_socket_sendmsg - Smack check based on destination host
2828 * @sock: the socket
2829 * @msg: the message
2830 * @size: the size of the message
2831 *
2832 * Return 0 if the current subject can write to the destination
2833 * host. This is only a question if the destination is a single
2834 * label host.
2835 */
2836static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2837                                int size)
2838{
2839        struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2840
2841        /*
2842         * Perfectly reasonable for this to be NULL
2843         */
2844        if (sip == NULL || sip->sin_family != AF_INET)
2845                return 0;
2846
2847        return smack_netlabel_send(sock->sk, sip);
2848}
2849
2850/**
2851 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2852 * @sap: netlabel secattr
2853 * @ssp: socket security information
2854 *
2855 * Returns a pointer to a Smack label found on the label list.
2856 */
2857static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
2858                                struct socket_smack *ssp)
2859{
2860        struct smack_known *kp;
2861        char *sp;
2862        int found = 0;
2863
2864        if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2865                /*
2866                 * Looks like a CIPSO packet.
2867                 * If there are flags but no level netlabel isn't
2868                 * behaving the way we expect it to.
2869                 *
2870                 * Look it up in the label table
2871                 * Without guidance regarding the smack value
2872                 * for the packet fall back on the network
2873                 * ambient value.
2874                 */
2875                rcu_read_lock();
2876                list_for_each_entry(kp, &smack_known_list, list) {
2877                        if (sap->attr.mls.lvl != kp->smk_netlabel.attr.mls.lvl)
2878                                continue;
2879                        if (memcmp(sap->attr.mls.cat,
2880                                kp->smk_netlabel.attr.mls.cat,
2881                                SMK_CIPSOLEN) != 0)
2882                                continue;
2883                        found = 1;
2884                        break;
2885                }
2886                rcu_read_unlock();
2887
2888                if (found)
2889                        return kp->smk_known;
2890
2891                if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
2892                        return smack_known_web.smk_known;
2893                return smack_known_star.smk_known;
2894        }
2895        if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2896                /*
2897                 * Looks like a fallback, which gives us a secid.
2898                 */
2899                sp = smack_from_secid(sap->attr.secid);
2900                /*
2901                 * This has got to be a bug because it is
2902                 * impossible to specify a fallback without
2903                 * specifying the label, which will ensure
2904                 * it has a secid, and the only way to get a
2905                 * secid is from a fallback.
2906                 */
2907                BUG_ON(sp == NULL);
2908                return sp;
2909        }
2910        /*
2911         * Without guidance regarding the smack value
2912         * for the packet fall back on the network
2913         * ambient value.
2914         */
2915        return smack_net_ambient;
2916}
2917
2918/**
2919 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2920 * @sk: socket
2921 * @skb: packet
2922 *
2923 * Returns 0 if the packet should be delivered, an error code otherwise
2924 */
2925static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2926{
2927        struct netlbl_lsm_secattr secattr;
2928        struct socket_smack *ssp = sk->sk_security;
2929        char *csp;
2930        int rc;
2931        struct smk_audit_info ad;
2932#ifdef CONFIG_AUDIT
2933        struct lsm_network_audit net;
2934#endif
2935        if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2936                return 0;
2937
2938        /*
2939         * Translate what netlabel gave us.
2940         */
2941        netlbl_secattr_init(&secattr);
2942
2943        rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2944        if (rc == 0)
2945                csp = smack_from_secattr(&secattr, ssp);
2946        else
2947                csp = smack_net_ambient;
2948
2949        netlbl_secattr_destroy(&secattr);
2950
2951#ifdef CONFIG_AUDIT
2952        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2953        ad.a.u.net->family = sk->sk_family;
2954        ad.a.u.net->netif = skb->skb_iif;
2955        ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2956#endif
2957        /*
2958         * Receiving a packet requires that the other end
2959         * be able to write here. Read access is not required.
2960         * This is the simplist possible security model
2961         * for networking.
2962         */
2963        rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2964        if (rc != 0)
2965                netlbl_skbuff_err(skb, rc, 0);
2966        return rc;
2967}
2968
2969/**
2970 * smack_socket_getpeersec_stream - pull in packet label
2971 * @sock: the socket
2972 * @optval: user's destination
2973 * @optlen: size thereof
2974 * @len: max thereof
2975 *
2976 * returns zero on success, an error code otherwise
2977 */
2978static int smack_socket_getpeersec_stream(struct socket *sock,
2979                                          char __user *optval,
2980                                          int __user *optlen, unsigned len)
2981{
2982        struct socket_smack *ssp;
2983        char *rcp = "";
2984        int slen = 1;
2985        int rc = 0;
2986
2987        ssp = sock->sk->sk_security;
2988        if (ssp->smk_packet != NULL) {
2989                rcp = ssp->smk_packet;
2990                slen = strlen(rcp) + 1;
2991        }
2992
2993        if (slen > len)
2994                rc = -ERANGE;
2995        else if (copy_to_user(optval, rcp, slen) != 0)
2996                rc = -EFAULT;
2997
2998        if (put_user(slen, optlen) != 0)
2999                rc = -EFAULT;
3000
3001        return rc;
3002}
3003
3004
3005/**
3006 * smack_socket_getpeersec_dgram - pull in packet label
3007 * @sock: the peer socket
3008 * @skb: packet data
3009 * @secid: pointer to where to put the secid of the packet
3010 *
3011 * Sets the netlabel socket state on sk from parent
3012 */
3013static int smack_socket_getpeersec_dgram(struct socket *sock,
3014                                         struct sk_buff *skb, u32 *secid)
3015
3016{
3017        struct netlbl_lsm_secattr secattr;
3018        struct socket_smack *ssp = NULL;
3019        char *sp;
3020        int family = PF_UNSPEC;
3021        u32 s = 0;      /* 0 is the invalid secid */
3022        int rc;
3023
3024        if (skb != NULL) {
3025                if (skb->protocol == htons(ETH_P_IP))
3026                        family = PF_INET;
3027                else if (skb->protocol == htons(ETH_P_IPV6))
3028                        family = PF_INET6;
3029        }
3030        if (family == PF_UNSPEC && sock != NULL)
3031                family = sock->sk->sk_family;
3032
3033        if (family == PF_UNIX) {
3034                ssp = sock->sk->sk_security;
3035                s = smack_to_secid(ssp->smk_out);
3036        } else if (family == PF_INET || family == PF_INET6) {
3037                /*
3038                 * Translate what netlabel gave us.
3039                 */
3040                if (sock != NULL && sock->sk != NULL)
3041                        ssp = sock->sk->sk_security;
3042                netlbl_secattr_init(&secattr);
3043                rc = netlbl_skbuff_getattr(skb, family, &secattr);
3044                if (rc == 0) {
3045                        sp = smack_from_secattr(&secattr, ssp);
3046                        s = smack_to_secid(sp);
3047                }
3048                netlbl_secattr_destroy(&secattr);
3049        }
3050        *secid = s;
3051        if (s == 0)
3052                return -EINVAL;
3053        return 0;
3054}
3055
3056/**
3057 * smack_sock_graft - Initialize a newly created socket with an existing sock
3058 * @sk: child sock
3059 * @parent: parent socket
3060 *
3061 * Set the smk_{in,out} state of an existing sock based on the process that
3062 * is creating the new socket.
3063 */
3064static void smack_sock_graft(struct sock *sk, struct socket *parent)
3065{
3066        struct socket_smack *ssp;
3067
3068        if (sk == NULL ||
3069            (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3070                return;
3071
3072        ssp = sk->sk_security;
3073        ssp->smk_in = ssp->smk_out = smk_of_current();
3074        /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3075}
3076
3077/**
3078 * smack_inet_conn_request - Smack access check on connect
3079 * @sk: socket involved
3080 * @skb: packet
3081 * @req: unused
3082 *
3083 * Returns 0 if a task with the packet label could write to
3084 * the socket, otherwise an error code
3085 */
3086static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3087                                   struct request_sock *req)
3088{
3089        u16 family = sk->sk_family;
3090        struct smack_known *skp;
3091        struct socket_smack *ssp = sk->sk_security;
3092        struct netlbl_lsm_secattr secattr;
3093        struct sockaddr_in addr;
3094        struct iphdr *hdr;
3095        char *sp;
3096        char *hsp;
3097        int rc;
3098        struct smk_audit_info ad;
3099#ifdef CONFIG_AUDIT
3100        struct lsm_network_audit net;
3101#endif
3102
3103        /* handle mapped IPv4 packets arriving via IPv6 sockets */
3104        if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3105                family = PF_INET;
3106
3107        netlbl_secattr_init(&secattr);
3108        rc = netlbl_skbuff_getattr(skb, family, &secattr);
3109        if (rc == 0)
3110                sp = smack_from_secattr(&secattr, ssp);
3111        else
3112                sp = smack_known_huh.smk_known;
3113        netlbl_secattr_destroy(&secattr);
3114
3115#ifdef CONFIG_AUDIT
3116        smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3117        ad.a.u.net->family = family;
3118        ad.a.u.net->netif = skb->skb_iif;
3119        ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3120#endif
3121        /*
3122         * Receiving a packet requires that the other end be able to write
3123         * here. Read access is not required.
3124         */
3125        rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
3126        if (rc != 0)
3127                return rc;
3128
3129        /*
3130         * Save the peer's label in the request_sock so we can later setup
3131         * smk_packet in the child socket so that SO_PEERCRED can report it.
3132         */
3133        req->peer_secid = smack_to_secid(sp);
3134
3135        /*
3136         * We need to decide if we want to label the incoming connection here
3137         * if we do we only need to label the request_sock and the stack will
3138         * propagate the wire-label to the sock when it is created.
3139         */
3140        hdr = ip_hdr(skb);
3141        addr.sin_addr.s_addr = hdr->saddr;
3142        rcu_read_lock();
3143        hsp = smack_host_label(&addr);
3144        rcu_read_unlock();
3145
3146        if (hsp == NULL) {
3147                skp = smk_find_entry(sp);
3148                rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3149        } else
3150                netlbl_req_delattr(req);
3151
3152        return rc;
3153}
3154
3155/**
3156 * smack_inet_csk_clone - Copy the connection information to the new socket
3157 * @sk: the new socket
3158 * @req: the connection's request_sock
3159 *
3160 * Transfer the connection's peer label to the newly created socket.
3161 */
3162static void smack_inet_csk_clone(struct sock *sk,
3163                                 const struct request_sock *req)
3164{
3165        struct socket_smack *ssp = sk->sk_security;
3166
3167        if (req->peer_secid != 0)
3168                ssp->smk_packet = smack_from_secid(req->peer_secid);
3169        else
3170                ssp->smk_packet = NULL;
3171}
3172
3173/*
3174 * Key management security hooks
3175 *
3176 * Casey has not tested key support very heavily.
3177 * The permission check is most likely too restrictive.
3178 * If you care about keys please have a look.
3179 */
3180#ifdef CONFIG_KEYS
3181
3182/**
3183 * smack_key_alloc - Set the key security blob
3184 * @key: object
3185 * @cred: the credentials to use
3186 * @flags: unused
3187 *
3188 * No allocation required
3189 *
3190 * Returns 0
3191 */
3192static int smack_key_alloc(struct key *key, const struct cred *cred,
3193                           unsigned long flags)
3194{
3195        key->security = smk_of_task(cred->security);
3196        return 0;
3197}
3198
3199/**
3200 * smack_key_free - Clear the key security blob
3201 * @key: the object
3202 *
3203 * Clear the blob pointer
3204 */
3205static void smack_key_free(struct key *key)
3206{
3207        key->security = NULL;
3208}
3209
3210/*
3211 * smack_key_permission - Smack access on a key
3212 * @key_ref: gets to the object
3213 * @cred: the credentials to use
3214 * @perm: unused
3215 *
3216 * Return 0 if the task has read and write to the object,
3217 * an error code otherwise
3218 */
3219static int smack_key_permission(key_ref_t key_ref,
3220                                const struct cred *cred, key_perm_t perm)
3221{
3222        struct key *keyp;
3223        struct smk_audit_info ad;
3224        char *tsp = smk_of_task(cred->security);
3225
3226        keyp = key_ref_to_ptr(key_ref);
3227        if (keyp == NULL)
3228                return -EINVAL;
3229        /*
3230         * If the key hasn't been initialized give it access so that
3231         * it may do so.
3232         */
3233        if (keyp->security == NULL)
3234                return 0;
3235        /*
3236         * This should not occur
3237         */
3238        if (tsp == NULL)
3239                return -EACCES;
3240#ifdef CONFIG_AUDIT
3241        smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3242        ad.a.u.key_struct.key = keyp->serial;
3243        ad.a.u.key_struct.key_desc = keyp->description;
3244#endif
3245        return smk_access(tsp, keyp->security,
3246                                 MAY_READWRITE, &ad);
3247}
3248#endif /* CONFIG_KEYS */
3249
3250/*
3251 * Smack Audit hooks
3252 *
3253 * Audit requires a unique representation of each Smack specific
3254 * rule. This unique representation is used to distinguish the
3255 * object to be audited from remaining kernel objects and also
3256 * works as a glue between the audit hooks.
3257 *
3258 * Since repository entries are added but never deleted, we'll use
3259 * the smack_known label address related to the given audit rule as
3260 * the needed unique representation. This also better fits the smack
3261 * model where nearly everything is a label.
3262 */
3263#ifdef CONFIG_AUDIT
3264
3265/**
3266 * smack_audit_rule_init - Initialize a smack audit rule
3267 * @field: audit rule fields given from user-space (audit.h)
3268 * @op: required testing operator (=, !=, >, <, ...)
3269 * @rulestr: smack label to be audited
3270 * @vrule: pointer to save our own audit rule representation
3271 *
3272 * Prepare to audit cases where (@field @op @rulestr) is true.
3273 * The label to be audited is created if necessay.
3274 */
3275static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3276{
3277        char **rule = (char **)vrule;
3278        *rule = NULL;
3279
3280        if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3281                return -EINVAL;
3282
3283        if (op != Audit_equal && op != Audit_not_equal)
3284                return -EINVAL;
3285
3286        *rule = smk_import(rulestr, 0);
3287
3288        return 0;
3289}
3290
3291/**
3292 * smack_audit_rule_known - Distinguish Smack audit rules
3293 * @krule: rule of interest, in Audit kernel representation format
3294 *
3295 * This is used to filter Smack rules from remaining Audit ones.
3296 * If it's proved that this rule belongs to us, the
3297 * audit_rule_match hook will be called to do the final judgement.
3298 */
3299static int smack_audit_rule_known(struct audit_krule *krule)
3300{
3301        struct audit_field *f;
3302        int i;
3303
3304        for (i = 0; i < krule->field_count; i++) {
3305                f = &krule->fields[i];
3306
3307                if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3308                        return 1;
3309        }
3310
3311        return 0;
3312}
3313
3314/**
3315 * smack_audit_rule_match - Audit given object ?
3316 * @secid: security id for identifying the object to test
3317 * @field: audit rule flags given from user-space
3318 * @op: required testing operator
3319 * @vrule: smack internal rule presentation
3320 * @actx: audit context associated with the check
3321 *
3322 * The core Audit hook. It's used to take the decision of
3323 * whether to audit or not to audit a given object.
3324 */
3325static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3326                                  struct audit_context *actx)
3327{
3328        char *smack;
3329        char *rule = vrule;
3330
3331        if (!rule) {
3332                audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3333                          "Smack: missing rule\n");
3334                return -ENOENT;
3335        }
3336
3337        if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3338                return 0;
3339
3340        smack = smack_from_secid(secid);
3341
3342        /*
3343         * No need to do string comparisons. If a match occurs,
3344         * both pointers will point to the same smack_known
3345         * label.
3346         */
3347        if (op == Audit_equal)
3348                return (rule == smack);
3349        if (op == Audit_not_equal)
3350                return (rule != smack);
3351
3352        return 0;
3353}
3354
3355/**
3356 * smack_audit_rule_free - free smack rule representation
3357 * @vrule: rule to be freed.
3358 *
3359 * No memory was allocated.
3360 */
3361static void smack_audit_rule_free(void *vrule)
3362{
3363        /* No-op */
3364}
3365
3366#endif /* CONFIG_AUDIT */
3367
3368/**
3369 * smack_secid_to_secctx - return the smack label for a secid
3370 * @secid: incoming integer
3371 * @secdata: destination
3372 * @seclen: how long it is
3373 *
3374 * Exists for networking code.
3375 */
3376static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3377{
3378        char *sp = smack_from_secid(secid);
3379
3380        if (secdata)
3381                *secdata = sp;
3382        *seclen = strlen(sp);
3383        return 0;
3384}
3385
3386/**
3387 * smack_secctx_to_secid - return the secid for a smack label
3388 * @secdata: smack label
3389 * @seclen: how long result is
3390 * @secid: outgoing integer
3391 *
3392 * Exists for audit and networking code.
3393 */
3394static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3395{
3396        *secid = smack_to_secid(secdata);
3397        return 0;
3398}
3399
3400/**
3401 * smack_release_secctx - don't do anything.
3402 * @secdata: unused
3403 * @seclen: unused
3404 *
3405 * Exists to make sure nothing gets done, and properly
3406 */
3407static void smack_release_secctx(char *secdata, u32 seclen)
3408{
3409}
3410
3411static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3412{
3413        return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3414}
3415
3416static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3417{
3418        return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3419}
3420
3421static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3422{
3423        int len = 0;
3424        len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3425
3426        if (len < 0)
3427                return len;
3428        *ctxlen = len;
3429        return 0;
3430}
3431
3432struct security_operations smack_ops = {
3433        .name =                         "smack",
3434
3435        .ptrace_access_check =          smack_ptrace_access_check,
3436        .ptrace_traceme =               smack_ptrace_traceme,
3437        .syslog =                       smack_syslog,
3438
3439        .sb_alloc_security =            smack_sb_alloc_security,
3440        .sb_free_security =             smack_sb_free_security,
3441        .sb_copy_data =                 smack_sb_copy_data,
3442        .sb_kern_mount =                smack_sb_kern_mount,
3443        .sb_statfs =                    smack_sb_statfs,
3444        .sb_mount =                     smack_sb_mount,
3445        .sb_umount =                    smack_sb_umount,
3446
3447        .bprm_set_creds =               smack_bprm_set_creds,
3448        .bprm_committing_creds =        smack_bprm_committing_creds,
3449        .bprm_secureexec =              smack_bprm_secureexec,
3450
3451        .inode_alloc_security =         smack_inode_alloc_security,
3452        .inode_free_security =          smack_inode_free_security,
3453        .inode_init_security =          smack_inode_init_security,
3454        .inode_link =                   smack_inode_link,
3455        .inode_unlink =                 smack_inode_unlink,
3456        .inode_rmdir =                  smack_inode_rmdir,
3457        .inode_rename =                 smack_inode_rename,
3458        .inode_permission =             smack_inode_permission,
3459        .inode_setattr =                smack_inode_setattr,
3460        .inode_getattr =                smack_inode_getattr,
3461        .inode_setxattr =               smack_inode_setxattr,
3462        .inode_post_setxattr =          smack_inode_post_setxattr,
3463        .inode_getxattr =               smack_inode_getxattr,
3464        .inode_removexattr =            smack_inode_removexattr,
3465        .inode_getsecurity =            smack_inode_getsecurity,
3466        .inode_setsecurity =            smack_inode_setsecurity,
3467        .inode_listsecurity =           smack_inode_listsecurity,
3468        .inode_getsecid =               smack_inode_getsecid,
3469
3470        .file_permission =              smack_file_permission,
3471        .file_alloc_security =          smack_file_alloc_security,
3472        .file_free_security =           smack_file_free_security,
3473        .file_ioctl =                   smack_file_ioctl,
3474        .file_lock =                    smack_file_lock,
3475        .file_fcntl =                   smack_file_fcntl,
3476        .mmap_file =                    smack_mmap_file,
3477        .mmap_addr =                    cap_mmap_addr,
3478        .file_set_fowner =              smack_file_set_fowner,
3479        .file_send_sigiotask =          smack_file_send_sigiotask,
3480        .file_receive =                 smack_file_receive,
3481
3482        .file_open =                    smack_file_open,
3483
3484        .cred_alloc_blank =             smack_cred_alloc_blank,
3485        .cred_free =                    smack_cred_free,
3486        .cred_prepare =                 smack_cred_prepare,
3487        .cred_transfer =                smack_cred_transfer,
3488        .kernel_act_as =                smack_kernel_act_as,
3489        .kernel_create_files_as =       smack_kernel_create_files_as,
3490        .task_setpgid =                 smack_task_setpgid,
3491        .task_getpgid =                 smack_task_getpgid,
3492        .task_getsid =                  smack_task_getsid,
3493        .task_getsecid =                smack_task_getsecid,
3494        .task_setnice =                 smack_task_setnice,
3495        .task_setioprio =               smack_task_setioprio,
3496        .task_getioprio =               smack_task_getioprio,
3497        .task_setscheduler =            smack_task_setscheduler,
3498        .task_getscheduler =            smack_task_getscheduler,
3499        .task_movememory =              smack_task_movememory,
3500        .task_kill =                    smack_task_kill,
3501        .task_wait =                    smack_task_wait,
3502        .task_to_inode =                smack_task_to_inode,
3503
3504        .ipc_permission =               smack_ipc_permission,
3505        .ipc_getsecid =                 smack_ipc_getsecid,
3506
3507        .msg_msg_alloc_security =       smack_msg_msg_alloc_security,
3508        .msg_msg_free_security =        smack_msg_msg_free_security,
3509
3510        .msg_queue_alloc_security =     smack_msg_queue_alloc_security,
3511        .msg_queue_free_security =      smack_msg_queue_free_security,
3512        .msg_queue_associate =          smack_msg_queue_associate,
3513        .msg_queue_msgctl =             smack_msg_queue_msgctl,
3514        .msg_queue_msgsnd =             smack_msg_queue_msgsnd,
3515        .msg_queue_msgrcv =             smack_msg_queue_msgrcv,
3516
3517        .shm_alloc_security =           smack_shm_alloc_security,
3518        .shm_free_security =            smack_shm_free_security,
3519        .shm_associate =                smack_shm_associate,
3520        .shm_shmctl =                   smack_shm_shmctl,
3521        .shm_shmat =                    smack_shm_shmat,
3522
3523        .sem_alloc_security =           smack_sem_alloc_security,
3524        .sem_free_security =            smack_sem_free_security,
3525        .sem_associate =                smack_sem_associate,
3526        .sem_semctl =                   smack_sem_semctl,
3527        .sem_semop =                    smack_sem_semop,
3528
3529        .d_instantiate =                smack_d_instantiate,
3530
3531        .getprocattr =                  smack_getprocattr,
3532        .setprocattr =                  smack_setprocattr,
3533
3534        .unix_stream_connect =          smack_unix_stream_connect,
3535        .unix_may_send =                smack_unix_may_send,
3536
3537        .socket_post_create =           smack_socket_post_create,
3538        .socket_connect =               smack_socket_connect,
3539        .socket_sendmsg =               smack_socket_sendmsg,
3540        .socket_sock_rcv_skb =          smack_socket_sock_rcv_skb,
3541        .socket_getpeersec_stream =     smack_socket_getpeersec_stream,
3542        .socket_getpeersec_dgram =      smack_socket_getpeersec_dgram,
3543        .sk_alloc_security =            smack_sk_alloc_security,
3544        .sk_free_security =             smack_sk_free_security,
3545        .sock_graft =                   smack_sock_graft,
3546        .inet_conn_request =            smack_inet_conn_request,
3547        .inet_csk_clone =               smack_inet_csk_clone,
3548
3549 /* key management security hooks */
3550#ifdef CONFIG_KEYS
3551        .key_alloc =                    smack_key_alloc,
3552        .key_free =                     smack_key_free,
3553        .key_permission =               smack_key_permission,
3554#endif /* CONFIG_KEYS */
3555
3556 /* Audit hooks */
3557#ifdef CONFIG_AUDIT
3558        .audit_rule_init =              smack_audit_rule_init,
3559        .audit_rule_known =             smack_audit_rule_known,
3560        .audit_rule_match =             smack_audit_rule_match,
3561        .audit_rule_free =              smack_audit_rule_free,
3562#endif /* CONFIG_AUDIT */
3563
3564        .secid_to_secctx =              smack_secid_to_secctx,
3565        .secctx_to_secid =              smack_secctx_to_secid,
3566        .release_secctx =               smack_release_secctx,
3567        .inode_notifysecctx =           smack_inode_notifysecctx,
3568        .inode_setsecctx =              smack_inode_setsecctx,
3569        .inode_getsecctx =              smack_inode_getsecctx,
3570};
3571
3572
3573static __init void init_smack_known_list(void)
3574{
3575        /*
3576         * Initialize rule list locks
3577         */
3578        mutex_init(&smack_known_huh.smk_rules_lock);
3579        mutex_init(&smack_known_hat.smk_rules_lock);
3580        mutex_init(&smack_known_floor.smk_rules_lock);
3581        mutex_init(&smack_known_star.smk_rules_lock);
3582        mutex_init(&smack_known_invalid.smk_rules_lock);
3583        mutex_init(&smack_known_web.smk_rules_lock);
3584        /*
3585         * Initialize rule lists
3586         */
3587        INIT_LIST_HEAD(&smack_known_huh.smk_rules);
3588        INIT_LIST_HEAD(&smack_known_hat.smk_rules);
3589        INIT_LIST_HEAD(&smack_known_star.smk_rules);
3590        INIT_LIST_HEAD(&smack_known_floor.smk_rules);
3591        INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
3592        INIT_LIST_HEAD(&smack_known_web.smk_rules);
3593        /*
3594         * Create the known labels list
3595         */
3596        list_add(&smack_known_huh.list, &smack_known_list);
3597        list_add(&smack_known_hat.list, &smack_known_list);
3598        list_add(&smack_known_star.list, &smack_known_list);
3599        list_add(&smack_known_floor.list, &smack_known_list);
3600        list_add(&smack_known_invalid.list, &smack_known_list);
3601        list_add(&smack_known_web.list, &smack_known_list);
3602}
3603
3604/**
3605 * smack_init - initialize the smack system
3606 *
3607 * Returns 0
3608 */
3609static __init int smack_init(void)
3610{
3611        struct cred *cred;
3612        struct task_smack *tsp;
3613
3614        if (!security_module_enable(&smack_ops))
3615                return 0;
3616
3617        tsp = new_task_smack(smack_known_floor.smk_known,
3618                                smack_known_floor.smk_known, GFP_KERNEL);
3619        if (tsp == NULL)
3620                return -ENOMEM;
3621
3622        printk(KERN_INFO "Smack:  Initializing.\n");
3623
3624        /*
3625         * Set the security state for the initial task.
3626         */
3627        cred = (struct cred *) current->cred;
3628        cred->security = tsp;
3629
3630        /* initialize the smack_known_list */
3631        init_smack_known_list();
3632
3633        /*
3634         * Register with LSM
3635         */
3636        if (register_security(&smack_ops))
3637                panic("smack: Unable to register with kernel.\n");
3638
3639        return 0;
3640}
3641
3642/*
3643 * Smack requires early initialization in order to label
3644 * all processes and objects when they are created.
3645 */
3646security_initcall(smack_init);
3647
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