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 *  Author:
   7 *      Casey Schaufler <casey@schaufler-ca.com>
   8 *
   9 *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
  10 *
  11 *      This program is free software; you can redistribute it and/or modify
  12 *      it under the terms of the GNU General Public License version 2,
  13 *      as published by the Free Software Foundation.
  14 */
  15
  16#include <linux/xattr.h>
  17#include <linux/pagemap.h>
  18#include <linux/mount.h>
  19#include <linux/stat.h>
  20#include <linux/ext2_fs.h>
  21#include <linux/kd.h>
  22#include <asm/ioctls.h>
  23#include <linux/tcp.h>
  24#include <linux/udp.h>
  25#include <linux/mutex.h>
  26#include <linux/pipe_fs_i.h>
  27#include <net/netlabel.h>
  28#include <net/cipso_ipv4.h>
  29#include <linux/audit.h>
  30
  31#include "smack.h"
  32
  33/*
  34 * I hope these are the hokeyist lines of code in the module. Casey.
  35 */
  36#define DEVPTS_SUPER_MAGIC      0x1cd1
  37#define SOCKFS_MAGIC            0x534F434B
  38#define TMPFS_MAGIC             0x01021994
  39
  40/**
  41 * smk_fetch - Fetch the smack label from a file.
  42 * @ip: a pointer to the inode
  43 * @dp: a pointer to the dentry
  44 *
  45 * Returns a pointer to the master list entry for the Smack label
  46 * or NULL if there was no label to fetch.
  47 */
  48static char *smk_fetch(struct inode *ip, struct dentry *dp)
  49{
  50        int rc;
  51        char in[SMK_LABELLEN];
  52
  53        if (ip->i_op->getxattr == NULL)
  54                return NULL;
  55
  56        rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN);
  57        if (rc < 0)
  58                return NULL;
  59
  60        return smk_import(in, rc);
  61}
  62
  63/**
  64 * new_inode_smack - allocate an inode security blob
  65 * @smack: a pointer to the Smack label to use in the blob
  66 *
  67 * Returns the new blob or NULL if there's no memory available
  68 */
  69struct inode_smack *new_inode_smack(char *smack)
  70{
  71        struct inode_smack *isp;
  72
  73        isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
  74        if (isp == NULL)
  75                return NULL;
  76
  77        isp->smk_inode = smack;
  78        isp->smk_flags = 0;
  79        mutex_init(&isp->smk_lock);
  80
  81        return isp;
  82}
  83
  84/*
  85 * LSM hooks.
  86 * We he, that is fun!
  87 */
  88
  89/**
  90 * smack_ptrace_may_access - Smack approval on PTRACE_ATTACH
  91 * @ctp: child task pointer
  92 *
  93 * Returns 0 if access is OK, an error code otherwise
  94 *
  95 * Do the capability checks, and require read and write.
  96 */
  97static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
  98{
  99        int rc;
 100
 101        rc = cap_ptrace_may_access(ctp, mode);
 102        if (rc != 0)
 103                return rc;
 104
 105        rc = smk_access(current->security, ctp->security, MAY_READWRITE);
 106        if (rc != 0 && capable(CAP_MAC_OVERRIDE))
 107                return 0;
 108        return rc;
 109}
 110
 111/**
 112 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
 113 * @ptp: parent task pointer
 114 *
 115 * Returns 0 if access is OK, an error code otherwise
 116 *
 117 * Do the capability checks, and require read and write.
 118 */
 119static int smack_ptrace_traceme(struct task_struct *ptp)
 120{
 121        int rc;
 122
 123        rc = cap_ptrace_traceme(ptp);
 124        if (rc != 0)
 125                return rc;
 126
 127        rc = smk_access(ptp->security, current->security, MAY_READWRITE);
 128        if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
 129                return 0;
 130        return rc;
 131}
 132
 133/**
 134 * smack_syslog - Smack approval on syslog
 135 * @type: message type
 136 *
 137 * Require that the task has the floor label
 138 *
 139 * Returns 0 on success, error code otherwise.
 140 */
 141static int smack_syslog(int type)
 142{
 143        int rc;
 144        char *sp = current->security;
 145
 146        rc = cap_syslog(type);
 147        if (rc != 0)
 148                return rc;
 149
 150        if (capable(CAP_MAC_OVERRIDE))
 151                return 0;
 152
 153         if (sp != smack_known_floor.smk_known)
 154                rc = -EACCES;
 155
 156        return rc;
 157}
 158
 159
 160/*
 161 * Superblock Hooks.
 162 */
 163
 164/**
 165 * smack_sb_alloc_security - allocate a superblock blob
 166 * @sb: the superblock getting the blob
 167 *
 168 * Returns 0 on success or -ENOMEM on error.
 169 */
 170static int smack_sb_alloc_security(struct super_block *sb)
 171{
 172        struct superblock_smack *sbsp;
 173
 174        sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
 175
 176        if (sbsp == NULL)
 177                return -ENOMEM;
 178
 179        sbsp->smk_root = smack_known_floor.smk_known;
 180        sbsp->smk_default = smack_known_floor.smk_known;
 181        sbsp->smk_floor = smack_known_floor.smk_known;
 182        sbsp->smk_hat = smack_known_hat.smk_known;
 183        sbsp->smk_initialized = 0;
 184        spin_lock_init(&sbsp->smk_sblock);
 185
 186        sb->s_security = sbsp;
 187
 188        return 0;
 189}
 190
 191/**
 192 * smack_sb_free_security - free a superblock blob
 193 * @sb: the superblock getting the blob
 194 *
 195 */
 196static void smack_sb_free_security(struct super_block *sb)
 197{
 198        kfree(sb->s_security);
 199        sb->s_security = NULL;
 200}
 201
 202/**
 203 * smack_sb_copy_data - copy mount options data for processing
 204 * @type: file system type
 205 * @orig: where to start
 206 * @smackopts
 207 *
 208 * Returns 0 on success or -ENOMEM on error.
 209 *
 210 * Copy the Smack specific mount options out of the mount
 211 * options list.
 212 */
 213static int smack_sb_copy_data(char *orig, char *smackopts)
 214{
 215        char *cp, *commap, *otheropts, *dp;
 216
 217        otheropts = (char *)get_zeroed_page(GFP_KERNEL);
 218        if (otheropts == NULL)
 219                return -ENOMEM;
 220
 221        for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
 222                if (strstr(cp, SMK_FSDEFAULT) == cp)
 223                        dp = smackopts;
 224                else if (strstr(cp, SMK_FSFLOOR) == cp)
 225                        dp = smackopts;
 226                else if (strstr(cp, SMK_FSHAT) == cp)
 227                        dp = smackopts;
 228                else if (strstr(cp, SMK_FSROOT) == cp)
 229                        dp = smackopts;
 230                else
 231                        dp = otheropts;
 232
 233                commap = strchr(cp, ',');
 234                if (commap != NULL)
 235                        *commap = '\0';
 236
 237                if (*dp != '\0')
 238                        strcat(dp, ",");
 239                strcat(dp, cp);
 240        }
 241
 242        strcpy(orig, otheropts);
 243        free_page((unsigned long)otheropts);
 244
 245        return 0;
 246}
 247
 248/**
 249 * smack_sb_kern_mount - Smack specific mount processing
 250 * @sb: the file system superblock
 251 * @data: the smack mount options
 252 *
 253 * Returns 0 on success, an error code on failure
 254 */
 255static int smack_sb_kern_mount(struct super_block *sb, void *data)
 256{
 257        struct dentry *root = sb->s_root;
 258        struct inode *inode = root->d_inode;
 259        struct superblock_smack *sp = sb->s_security;
 260        struct inode_smack *isp;
 261        char *op;
 262        char *commap;
 263        char *nsp;
 264
 265        spin_lock(&sp->smk_sblock);
 266        if (sp->smk_initialized != 0) {
 267                spin_unlock(&sp->smk_sblock);
 268                return 0;
 269        }
 270        sp->smk_initialized = 1;
 271        spin_unlock(&sp->smk_sblock);
 272
 273        for (op = data; op != NULL; op = commap) {
 274                commap = strchr(op, ',');
 275                if (commap != NULL)
 276                        *commap++ = '\0';
 277
 278                if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
 279                        op += strlen(SMK_FSHAT);
 280                        nsp = smk_import(op, 0);
 281                        if (nsp != NULL)
 282                                sp->smk_hat = nsp;
 283                } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
 284                        op += strlen(SMK_FSFLOOR);
 285                        nsp = smk_import(op, 0);
 286                        if (nsp != NULL)
 287                                sp->smk_floor = nsp;
 288                } else if (strncmp(op, SMK_FSDEFAULT,
 289                                   strlen(SMK_FSDEFAULT)) == 0) {
 290                        op += strlen(SMK_FSDEFAULT);
 291                        nsp = smk_import(op, 0);
 292                        if (nsp != NULL)
 293                                sp->smk_default = nsp;
 294                } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
 295                        op += strlen(SMK_FSROOT);
 296                        nsp = smk_import(op, 0);
 297                        if (nsp != NULL)
 298                                sp->smk_root = nsp;
 299                }
 300        }
 301
 302        /*
 303         * Initialize the root inode.
 304         */
 305        isp = inode->i_security;
 306        if (isp == NULL)
 307                inode->i_security = new_inode_smack(sp->smk_root);
 308        else
 309                isp->smk_inode = sp->smk_root;
 310
 311        return 0;
 312}
 313
 314/**
 315 * smack_sb_statfs - Smack check on statfs
 316 * @dentry: identifies the file system in question
 317 *
 318 * Returns 0 if current can read the floor of the filesystem,
 319 * and error code otherwise
 320 */
 321static int smack_sb_statfs(struct dentry *dentry)
 322{
 323        struct superblock_smack *sbp = dentry->d_sb->s_security;
 324
 325        return smk_curacc(sbp->smk_floor, MAY_READ);
 326}
 327
 328/**
 329 * smack_sb_mount - Smack check for mounting
 330 * @dev_name: unused
 331 * @nd: mount point
 332 * @type: unused
 333 * @flags: unused
 334 * @data: unused
 335 *
 336 * Returns 0 if current can write the floor of the filesystem
 337 * being mounted on, an error code otherwise.
 338 */
 339static int smack_sb_mount(char *dev_name, struct path *path,
 340                          char *type, unsigned long flags, void *data)
 341{
 342        struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
 343
 344        return smk_curacc(sbp->smk_floor, MAY_WRITE);
 345}
 346
 347/**
 348 * smack_sb_umount - Smack check for unmounting
 349 * @mnt: file system to unmount
 350 * @flags: unused
 351 *
 352 * Returns 0 if current can write the floor of the filesystem
 353 * being unmounted, an error code otherwise.
 354 */
 355static int smack_sb_umount(struct vfsmount *mnt, int flags)
 356{
 357        struct superblock_smack *sbp;
 358
 359        sbp = mnt->mnt_sb->s_security;
 360
 361        return smk_curacc(sbp->smk_floor, MAY_WRITE);
 362}
 363
 364/*
 365 * Inode hooks
 366 */
 367
 368/**
 369 * smack_inode_alloc_security - allocate an inode blob
 370 * @inode - the inode in need of a blob
 371 *
 372 * Returns 0 if it gets a blob, -ENOMEM otherwise
 373 */
 374static int smack_inode_alloc_security(struct inode *inode)
 375{
 376        inode->i_security = new_inode_smack(current->security);
 377        if (inode->i_security == NULL)
 378                return -ENOMEM;
 379        return 0;
 380}
 381
 382/**
 383 * smack_inode_free_security - free an inode blob
 384 * @inode - the inode with a blob
 385 *
 386 * Clears the blob pointer in inode
 387 */
 388static void smack_inode_free_security(struct inode *inode)
 389{
 390        kfree(inode->i_security);
 391        inode->i_security = NULL;
 392}
 393
 394/**
 395 * smack_inode_init_security - copy out the smack from an inode
 396 * @inode: the inode
 397 * @dir: unused
 398 * @name: where to put the attribute name
 399 * @value: where to put the attribute value
 400 * @len: where to put the length of the attribute
 401 *
 402 * Returns 0 if it all works out, -ENOMEM if there's no memory
 403 */
 404static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 405                                     char **name, void **value, size_t *len)
 406{
 407        char *isp = smk_of_inode(inode);
 408
 409        if (name) {
 410                *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
 411                if (*name == NULL)
 412                        return -ENOMEM;
 413        }
 414
 415        if (value) {
 416                *value = kstrdup(isp, GFP_KERNEL);
 417                if (*value == NULL)
 418                        return -ENOMEM;
 419        }
 420
 421        if (len)
 422                *len = strlen(isp) + 1;
 423
 424        return 0;
 425}
 426
 427/**
 428 * smack_inode_link - Smack check on link
 429 * @old_dentry: the existing object
 430 * @dir: unused
 431 * @new_dentry: the new object
 432 *
 433 * Returns 0 if access is permitted, an error code otherwise
 434 */
 435static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
 436                            struct dentry *new_dentry)
 437{
 438        int rc;
 439        char *isp;
 440
 441        isp = smk_of_inode(old_dentry->d_inode);
 442        rc = smk_curacc(isp, MAY_WRITE);
 443
 444        if (rc == 0 && new_dentry->d_inode != NULL) {
 445                isp = smk_of_inode(new_dentry->d_inode);
 446                rc = smk_curacc(isp, MAY_WRITE);
 447        }
 448
 449        return rc;
 450}
 451
 452/**
 453 * smack_inode_unlink - Smack check on inode deletion
 454 * @dir: containing directory object
 455 * @dentry: file to unlink
 456 *
 457 * Returns 0 if current can write the containing directory
 458 * and the object, error code otherwise
 459 */
 460static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
 461{
 462        struct inode *ip = dentry->d_inode;
 463        int rc;
 464
 465        /*
 466         * You need write access to the thing you're unlinking
 467         */
 468        rc = smk_curacc(smk_of_inode(ip), MAY_WRITE);
 469        if (rc == 0)
 470                /*
 471                 * You also need write access to the containing directory
 472                 */
 473                rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
 474
 475        return rc;
 476}
 477
 478/**
 479 * smack_inode_rmdir - Smack check on directory deletion
 480 * @dir: containing directory object
 481 * @dentry: directory to unlink
 482 *
 483 * Returns 0 if current can write the containing directory
 484 * and the directory, error code otherwise
 485 */
 486static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
 487{
 488        int rc;
 489
 490        /*
 491         * You need write access to the thing you're removing
 492         */
 493        rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
 494        if (rc == 0)
 495                /*
 496                 * You also need write access to the containing directory
 497                 */
 498                rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
 499
 500        return rc;
 501}
 502
 503/**
 504 * smack_inode_rename - Smack check on rename
 505 * @old_inode: the old directory
 506 * @old_dentry: unused
 507 * @new_inode: the new directory
 508 * @new_dentry: unused
 509 *
 510 * Read and write access is required on both the old and
 511 * new directories.
 512 *
 513 * Returns 0 if access is permitted, an error code otherwise
 514 */
 515static int smack_inode_rename(struct inode *old_inode,
 516                              struct dentry *old_dentry,
 517                              struct inode *new_inode,
 518                              struct dentry *new_dentry)
 519{
 520        int rc;
 521        char *isp;
 522
 523        isp = smk_of_inode(old_dentry->d_inode);
 524        rc = smk_curacc(isp, MAY_READWRITE);
 525
 526        if (rc == 0 && new_dentry->d_inode != NULL) {
 527                isp = smk_of_inode(new_dentry->d_inode);
 528                rc = smk_curacc(isp, MAY_READWRITE);
 529        }
 530
 531        return rc;
 532}
 533
 534/**
 535 * smack_inode_permission - Smack version of permission()
 536 * @inode: the inode in question
 537 * @mask: the access requested
 538 * @nd: unused
 539 *
 540 * This is the important Smack hook.
 541 *
 542 * Returns 0 if access is permitted, -EACCES otherwise
 543 */
 544static int smack_inode_permission(struct inode *inode, int mask)
 545{
 546        /*
 547         * No permission to check. Existence test. Yup, it's there.
 548         */
 549        if (mask == 0)
 550                return 0;
 551
 552        return smk_curacc(smk_of_inode(inode), mask);
 553}
 554
 555/**
 556 * smack_inode_setattr - Smack check for setting attributes
 557 * @dentry: the object
 558 * @iattr: for the force flag
 559 *
 560 * Returns 0 if access is permitted, an error code otherwise
 561 */
 562static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
 563{
 564        /*
 565         * Need to allow for clearing the setuid bit.
 566         */
 567        if (iattr->ia_valid & ATTR_FORCE)
 568                return 0;
 569
 570        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
 571}
 572
 573/**
 574 * smack_inode_getattr - Smack check for getting attributes
 575 * @mnt: unused
 576 * @dentry: the object
 577 *
 578 * Returns 0 if access is permitted, an error code otherwise
 579 */
 580static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
 581{
 582        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
 583}
 584
 585/**
 586 * smack_inode_setxattr - Smack check for setting xattrs
 587 * @dentry: the object
 588 * @name: name of the attribute
 589 * @value: unused
 590 * @size: unused
 591 * @flags: unused
 592 *
 593 * This protects the Smack attribute explicitly.
 594 *
 595 * Returns 0 if access is permitted, an error code otherwise
 596 */
 597static int smack_inode_setxattr(struct dentry *dentry, const char *name,
 598                                const void *value, size_t size, int flags)
 599{
 600        int rc = 0;
 601
 602        if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
 603            strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
 604            strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
 605                if (!capable(CAP_MAC_ADMIN))
 606                        rc = -EPERM;
 607        } else
 608                rc = cap_inode_setxattr(dentry, name, value, size, flags);
 609
 610        if (rc == 0)
 611                rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
 612
 613        return rc;
 614}
 615
 616/**
 617 * smack_inode_post_setxattr - Apply the Smack update approved above
 618 * @dentry: object
 619 * @name: attribute name
 620 * @value: attribute value
 621 * @size: attribute size
 622 * @flags: unused
 623 *
 624 * Set the pointer in the inode blob to the entry found
 625 * in the master label list.
 626 */
 627static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
 628                                      const void *value, size_t size, int flags)
 629{
 630        struct inode_smack *isp;
 631        char *nsp;
 632
 633        /*
 634         * Not SMACK
 635         */
 636        if (strcmp(name, XATTR_NAME_SMACK))
 637                return;
 638
 639        if (size >= SMK_LABELLEN)
 640                return;
 641
 642        isp = dentry->d_inode->i_security;
 643
 644        /*
 645         * No locking is done here. This is a pointer
 646         * assignment.
 647         */
 648        nsp = smk_import(value, size);
 649        if (nsp != NULL)
 650                isp->smk_inode = nsp;
 651        else
 652                isp->smk_inode = smack_known_invalid.smk_known;
 653
 654        return;
 655}
 656
 657/*
 658 * smack_inode_getxattr - Smack check on getxattr
 659 * @dentry: the object
 660 * @name: unused
 661 *
 662 * Returns 0 if access is permitted, an error code otherwise
 663 */
 664static int smack_inode_getxattr(struct dentry *dentry, const char *name)
 665{
 666        return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
 667}
 668
 669/*
 670 * smack_inode_removexattr - Smack check on removexattr
 671 * @dentry: the object
 672 * @name: name of the attribute
 673 *
 674 * Removing the Smack attribute requires CAP_MAC_ADMIN
 675 *
 676 * Returns 0 if access is permitted, an error code otherwise
 677 */
 678static int smack_inode_removexattr(struct dentry *dentry, const char *name)
 679{
 680        int rc = 0;
 681
 682        if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
 683            strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
 684            strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
 685                if (!capable(CAP_MAC_ADMIN))
 686                        rc = -EPERM;
 687        } else
 688                rc = cap_inode_removexattr(dentry, name);
 689
 690        if (rc == 0)
 691                rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
 692
 693        return rc;
 694}
 695
 696/**
 697 * smack_inode_getsecurity - get smack xattrs
 698 * @inode: the object
 699 * @name: attribute name
 700 * @buffer: where to put the result
 701 * @size: size of the buffer
 702 * @err: unused
 703 *
 704 * Returns the size of the attribute or an error code
 705 */
 706static int smack_inode_getsecurity(const struct inode *inode,
 707                                   const char *name, void **buffer,
 708                                   bool alloc)
 709{
 710        struct socket_smack *ssp;
 711        struct socket *sock;
 712        struct super_block *sbp;
 713        struct inode *ip = (struct inode *)inode;
 714        char *isp;
 715        int ilen;
 716        int rc = 0;
 717
 718        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
 719                isp = smk_of_inode(inode);
 720                ilen = strlen(isp) + 1;
 721                *buffer = isp;
 722                return ilen;
 723        }
 724
 725        /*
 726         * The rest of the Smack xattrs are only on sockets.
 727         */
 728        sbp = ip->i_sb;
 729        if (sbp->s_magic != SOCKFS_MAGIC)
 730                return -EOPNOTSUPP;
 731
 732        sock = SOCKET_I(ip);
 733        if (sock == NULL || sock->sk == NULL)
 734                return -EOPNOTSUPP;
 735
 736        ssp = sock->sk->sk_security;
 737
 738        if (strcmp(name, XATTR_SMACK_IPIN) == 0)
 739                isp = ssp->smk_in;
 740        else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
 741                isp = ssp->smk_out;
 742        else
 743                return -EOPNOTSUPP;
 744
 745        ilen = strlen(isp) + 1;
 746        if (rc == 0) {
 747                *buffer = isp;
 748                rc = ilen;
 749        }
 750
 751        return rc;
 752}
 753
 754
 755/**
 756 * smack_inode_listsecurity - list the Smack attributes
 757 * @inode: the object
 758 * @buffer: where they go
 759 * @buffer_size: size of buffer
 760 *
 761 * Returns 0 on success, -EINVAL otherwise
 762 */
 763static int smack_inode_listsecurity(struct inode *inode, char *buffer,
 764                                    size_t buffer_size)
 765{
 766        int len = strlen(XATTR_NAME_SMACK);
 767
 768        if (buffer != NULL && len <= buffer_size) {
 769                memcpy(buffer, XATTR_NAME_SMACK, len);
 770                return len;
 771        }
 772        return -EINVAL;
 773}
 774
 775/**
 776 * smack_inode_getsecid - Extract inode's security id
 777 * @inode: inode to extract the info from
 778 * @secid: where result will be saved
 779 */
 780static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
 781{
 782        struct inode_smack *isp = inode->i_security;
 783
 784        *secid = smack_to_secid(isp->smk_inode);
 785}
 786
 787/*
 788 * File Hooks
 789 */
 790
 791/**
 792 * smack_file_permission - Smack check on file operations
 793 * @file: unused
 794 * @mask: unused
 795 *
 796 * Returns 0
 797 *
 798 * Should access checks be done on each read or write?
 799 * UNICOS and SELinux say yes.
 800 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
 801 *
 802 * I'll say no for now. Smack does not do the frequent
 803 * label changing that SELinux does.
 804 */
 805static int smack_file_permission(struct file *file, int mask)
 806{
 807        return 0;
 808}
 809
 810/**
 811 * smack_file_alloc_security - assign a file security blob
 812 * @file: the object
 813 *
 814 * The security blob for a file is a pointer to the master
 815 * label list, so no allocation is done.
 816 *
 817 * Returns 0
 818 */
 819static int smack_file_alloc_security(struct file *file)
 820{
 821        file->f_security = current->security;
 822        return 0;
 823}
 824
 825/**
 826 * smack_file_free_security - clear a file security blob
 827 * @file: the object
 828 *
 829 * The security blob for a file is a pointer to the master
 830 * label list, so no memory is freed.
 831 */
 832static void smack_file_free_security(struct file *file)
 833{
 834        file->f_security = NULL;
 835}
 836
 837/**
 838 * smack_file_ioctl - Smack check on ioctls
 839 * @file: the object
 840 * @cmd: what to do
 841 * @arg: unused
 842 *
 843 * Relies heavily on the correct use of the ioctl command conventions.
 844 *
 845 * Returns 0 if allowed, error code otherwise
 846 */
 847static int smack_file_ioctl(struct file *file, unsigned int cmd,
 848                            unsigned long arg)
 849{
 850        int rc = 0;
 851
 852        if (_IOC_DIR(cmd) & _IOC_WRITE)
 853                rc = smk_curacc(file->f_security, MAY_WRITE);
 854
 855        if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
 856                rc = smk_curacc(file->f_security, MAY_READ);
 857
 858        return rc;
 859}
 860
 861/**
 862 * smack_file_lock - Smack check on file locking
 863 * @file: the object
 864 * @cmd unused
 865 *
 866 * Returns 0 if current has write access, error code otherwise
 867 */
 868static int smack_file_lock(struct file *file, unsigned int cmd)
 869{
 870        return smk_curacc(file->f_security, MAY_WRITE);
 871}
 872
 873/**
 874 * smack_file_fcntl - Smack check on fcntl
 875 * @file: the object
 876 * @cmd: what action to check
 877 * @arg: unused
 878 *
 879 * Returns 0 if current has access, error code otherwise
 880 */
 881static int smack_file_fcntl(struct file *file, unsigned int cmd,
 882                            unsigned long arg)
 883{
 884        int rc;
 885
 886        switch (cmd) {
 887        case F_DUPFD:
 888        case F_GETFD:
 889        case F_GETFL:
 890        case F_GETLK:
 891        case F_GETOWN:
 892        case F_GETSIG:
 893                rc = smk_curacc(file->f_security, MAY_READ);
 894                break;
 895        case F_SETFD:
 896        case F_SETFL:
 897        case F_SETLK:
 898        case F_SETLKW:
 899        case F_SETOWN:
 900        case F_SETSIG:
 901                rc = smk_curacc(file->f_security, MAY_WRITE);
 902                break;
 903        default:
 904                rc = smk_curacc(file->f_security, MAY_READWRITE);
 905        }
 906
 907        return rc;
 908}
 909
 910/**
 911 * smack_file_set_fowner - set the file security blob value
 912 * @file: object in question
 913 *
 914 * Returns 0
 915 * Further research may be required on this one.
 916 */
 917static int smack_file_set_fowner(struct file *file)
 918{
 919        file->f_security = current->security;
 920        return 0;
 921}
 922
 923/**
 924 * smack_file_send_sigiotask - Smack on sigio
 925 * @tsk: The target task
 926 * @fown: the object the signal come from
 927 * @signum: unused
 928 *
 929 * Allow a privileged task to get signals even if it shouldn't
 930 *
 931 * Returns 0 if a subject with the object's smack could
 932 * write to the task, an error code otherwise.
 933 */
 934static int smack_file_send_sigiotask(struct task_struct *tsk,
 935                                     struct fown_struct *fown, int signum)
 936{
 937        struct file *file;
 938        int rc;
 939
 940        /*
 941         * struct fown_struct is never outside the context of a struct file
 942         */
 943        file = container_of(fown, struct file, f_owner);
 944        rc = smk_access(file->f_security, tsk->security, MAY_WRITE);
 945        if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
 946                return 0;
 947        return rc;
 948}
 949
 950/**
 951 * smack_file_receive - Smack file receive check
 952 * @file: the object
 953 *
 954 * Returns 0 if current has access, error code otherwise
 955 */
 956static int smack_file_receive(struct file *file)
 957{
 958        int may = 0;
 959
 960        /*
 961         * This code relies on bitmasks.
 962         */
 963        if (file->f_mode & FMODE_READ)
 964                may = MAY_READ;
 965        if (file->f_mode & FMODE_WRITE)
 966                may |= MAY_WRITE;
 967
 968        return smk_curacc(file->f_security, may);
 969}
 970
 971/*
 972 * Task hooks
 973 */
 974
 975/**
 976 * smack_task_alloc_security - "allocate" a task blob
 977 * @tsk: the task in need of a blob
 978 *
 979 * Smack isn't using copies of blobs. Everyone
 980 * points to an immutable list. No alloc required.
 981 * No data copy required.
 982 *
 983 * Always returns 0
 984 */
 985static int smack_task_alloc_security(struct task_struct *tsk)
 986{
 987        tsk->security = current->security;
 988
 989        return 0;
 990}
 991
 992/**
 993 * smack_task_free_security - "free" a task blob
 994 * @task: the task with the blob
 995 *
 996 * Smack isn't using copies of blobs. Everyone
 997 * points to an immutable list. The blobs never go away.
 998 * There is no leak here.
 999 */
1000static void smack_task_free_security(struct task_struct *task)
1001{
1002        task->security = NULL;
1003}
1004
1005/**
1006 * smack_task_setpgid - Smack check on setting pgid
1007 * @p: the task object
1008 * @pgid: unused
1009 *
1010 * Return 0 if write access is permitted
1011 */
1012static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1013{
1014        return smk_curacc(p->security, MAY_WRITE);
1015}
1016
1017/**
1018 * smack_task_getpgid - Smack access check for getpgid
1019 * @p: the object task
1020 *
1021 * Returns 0 if current can read the object task, error code otherwise
1022 */
1023static int smack_task_getpgid(struct task_struct *p)
1024{
1025        return smk_curacc(p->security, MAY_READ);
1026}
1027
1028/**
1029 * smack_task_getsid - Smack access check for getsid
1030 * @p: the object task
1031 *
1032 * Returns 0 if current can read the object task, error code otherwise
1033 */
1034static int smack_task_getsid(struct task_struct *p)
1035{
1036        return smk_curacc(p->security, MAY_READ);
1037}
1038
1039/**
1040 * smack_task_getsecid - get the secid of the task
1041 * @p: the object task
1042 * @secid: where to put the result
1043 *
1044 * Sets the secid to contain a u32 version of the smack label.
1045 */
1046static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1047{
1048        *secid = smack_to_secid(p->security);
1049}
1050
1051/**
1052 * smack_task_setnice - Smack check on setting nice
1053 * @p: the task object
1054 * @nice: unused
1055 *
1056 * Return 0 if write access is permitted
1057 */
1058static int smack_task_setnice(struct task_struct *p, int nice)
1059{
1060        int rc;
1061
1062        rc = cap_task_setnice(p, nice);
1063        if (rc == 0)
1064                rc = smk_curacc(p->security, MAY_WRITE);
1065        return rc;
1066}
1067
1068/**
1069 * smack_task_setioprio - Smack check on setting ioprio
1070 * @p: the task object
1071 * @ioprio: unused
1072 *
1073 * Return 0 if write access is permitted
1074 */
1075static int smack_task_setioprio(struct task_struct *p, int ioprio)
1076{
1077        int rc;
1078
1079        rc = cap_task_setioprio(p, ioprio);
1080        if (rc == 0)
1081                rc = smk_curacc(p->security, MAY_WRITE);
1082        return rc;
1083}
1084
1085/**
1086 * smack_task_getioprio - Smack check on reading ioprio
1087 * @p: the task object
1088 *
1089 * Return 0 if read access is permitted
1090 */
1091static int smack_task_getioprio(struct task_struct *p)
1092{
1093        return smk_curacc(p->security, MAY_READ);
1094}
1095
1096/**
1097 * smack_task_setscheduler - Smack check on setting scheduler
1098 * @p: the task object
1099 * @policy: unused
1100 * @lp: unused
1101 *
1102 * Return 0 if read access is permitted
1103 */
1104static int smack_task_setscheduler(struct task_struct *p, int policy,
1105                                   struct sched_param *lp)
1106{
1107        int rc;
1108
1109        rc = cap_task_setscheduler(p, policy, lp);
1110        if (rc == 0)
1111                rc = smk_curacc(p->security, MAY_WRITE);
1112        return rc;
1113}
1114
1115/**
1116 * smack_task_getscheduler - Smack check on reading scheduler
1117 * @p: the task object
1118 *
1119 * Return 0 if read access is permitted
1120 */
1121static int smack_task_getscheduler(struct task_struct *p)
1122{
1123        return smk_curacc(p->security, MAY_READ);
1124}
1125
1126/**
1127 * smack_task_movememory - Smack check on moving memory
1128 * @p: the task object
1129 *
1130 * Return 0 if write access is permitted
1131 */
1132static int smack_task_movememory(struct task_struct *p)
1133{
1134        return smk_curacc(p->security, MAY_WRITE);
1135}
1136
1137/**
1138 * smack_task_kill - Smack check on signal delivery
1139 * @p: the task object
1140 * @info: unused
1141 * @sig: unused
1142 * @secid: identifies the smack to use in lieu of current's
1143 *
1144 * Return 0 if write access is permitted
1145 *
1146 * The secid behavior is an artifact of an SELinux hack
1147 * in the USB code. Someday it may go away.
1148 */
1149static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1150                           int sig, u32 secid)
1151{
1152        /*
1153         * Sending a signal requires that the sender
1154         * can write the receiver.
1155         */
1156        if (secid == 0)
1157                return smk_curacc(p->security, MAY_WRITE);
1158        /*
1159         * If the secid isn't 0 we're dealing with some USB IO
1160         * specific behavior. This is not clean. For one thing
1161         * we can't take privilege into account.
1162         */
1163        return smk_access(smack_from_secid(secid), p->security, MAY_WRITE);
1164}
1165
1166/**
1167 * smack_task_wait - Smack access check for waiting
1168 * @p: task to wait for
1169 *
1170 * Returns 0 if current can wait for p, error code otherwise
1171 */
1172static int smack_task_wait(struct task_struct *p)
1173{
1174        int rc;
1175
1176        rc = smk_access(current->security, p->security, MAY_WRITE);
1177        if (rc == 0)
1178                return 0;
1179
1180        /*
1181         * Allow the operation to succeed if either task
1182         * has privilege to perform operations that might
1183         * account for the smack labels having gotten to
1184         * be different in the first place.
1185         *
1186         * This breaks the strict subject/object access
1187         * control ideal, taking the object's privilege
1188         * state into account in the decision as well as
1189         * the smack value.
1190         */
1191        if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1192                return 0;
1193
1194        return rc;
1195}
1196
1197/**
1198 * smack_task_to_inode - copy task smack into the inode blob
1199 * @p: task to copy from
1200 * inode: inode to copy to
1201 *
1202 * Sets the smack pointer in the inode security blob
1203 */
1204static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1205{
1206        struct inode_smack *isp = inode->i_security;
1207        isp->smk_inode = p->security;
1208}
1209
1210/*
1211 * Socket hooks.
1212 */
1213
1214/**
1215 * smack_sk_alloc_security - Allocate a socket blob
1216 * @sk: the socket
1217 * @family: unused
1218 * @priority: memory allocation priority
1219 *
1220 * Assign Smack pointers to current
1221 *
1222 * Returns 0 on success, -ENOMEM is there's no memory
1223 */
1224static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1225{
1226        char *csp = current->security;
1227        struct socket_smack *ssp;
1228
1229        ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1230        if (ssp == NULL)
1231                return -ENOMEM;
1232
1233        ssp->smk_in = csp;
1234        ssp->smk_out = csp;
1235        ssp->smk_packet[0] = '\0';
1236
1237        sk->sk_security = ssp;
1238
1239        return 0;
1240}
1241
1242/**
1243 * smack_sk_free_security - Free a socket blob
1244 * @sk: the socket
1245 *
1246 * Clears the blob pointer
1247 */
1248static void smack_sk_free_security(struct sock *sk)
1249{
1250        kfree(sk->sk_security);
1251}
1252
1253/**
1254 * smack_set_catset - convert a capset to netlabel mls categories
1255 * @catset: the Smack categories
1256 * @sap: where to put the netlabel categories
1257 *
1258 * Allocates and fills attr.mls.cat
1259 */
1260static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1261{
1262        unsigned char *cp;
1263        unsigned char m;
1264        int cat;
1265        int rc;
1266        int byte;
1267
1268        if (!catset)
1269                return;
1270
1271        sap->flags |= NETLBL_SECATTR_MLS_CAT;
1272        sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1273        sap->attr.mls.cat->startbit = 0;
1274
1275        for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1276                for (m = 0x80; m != 0; m >>= 1, cat++) {
1277                        if ((m & *cp) == 0)
1278                                continue;
1279                        rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1280                                                          cat, GFP_ATOMIC);
1281                }
1282}
1283
1284/**
1285 * smack_to_secattr - fill a secattr from a smack value
1286 * @smack: the smack value
1287 * @nlsp: where the result goes
1288 *
1289 * Casey says that CIPSO is good enough for now.
1290 * It can be used to effect.
1291 * It can also be abused to effect when necessary.
1292 * Appologies to the TSIG group in general and GW in particular.
1293 */
1294static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1295{
1296        struct smack_cipso cipso;
1297        int rc;
1298
1299        switch (smack_net_nltype) {
1300        case NETLBL_NLTYPE_CIPSOV4:
1301                nlsp->domain = smack;
1302                nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1303
1304                rc = smack_to_cipso(smack, &cipso);
1305                if (rc == 0) {
1306                        nlsp->attr.mls.lvl = cipso.smk_level;
1307                        smack_set_catset(cipso.smk_catset, nlsp);
1308                } else {
1309                        nlsp->attr.mls.lvl = smack_cipso_direct;
1310                        smack_set_catset(smack, nlsp);
1311                }
1312                break;
1313        default:
1314                break;
1315        }
1316}
1317
1318/**
1319 * smack_netlabel - Set the secattr on a socket
1320 * @sk: the socket
1321 *
1322 * Convert the outbound smack value (smk_out) to a
1323 * secattr and attach it to the socket.
1324 *
1325 * Returns 0 on success or an error code
1326 */
1327static int smack_netlabel(struct sock *sk)
1328{
1329        struct socket_smack *ssp;
1330        struct netlbl_lsm_secattr secattr;
1331        int rc;
1332
1333        ssp = sk->sk_security;
1334        netlbl_secattr_init(&secattr);
1335        smack_to_secattr(ssp->smk_out, &secattr);
1336        rc = netlbl_sock_setattr(sk, &secattr);
1337        netlbl_secattr_destroy(&secattr);
1338
1339        return rc;
1340}
1341
1342/**
1343 * smack_inode_setsecurity - set smack xattrs
1344 * @inode: the object
1345 * @name: attribute name
1346 * @value: attribute value
1347 * @size: size of the attribute
1348 * @flags: unused
1349 *
1350 * Sets the named attribute in the appropriate blob
1351 *
1352 * Returns 0 on success, or an error code
1353 */
1354static int smack_inode_setsecurity(struct inode *inode, const char *name,
1355                                   const void *value, size_t size, int flags)
1356{
1357        char *sp;
1358        struct inode_smack *nsp = inode->i_security;
1359        struct socket_smack *ssp;
1360        struct socket *sock;
1361        int rc = 0;
1362
1363        if (value == NULL || size > SMK_LABELLEN)
1364                return -EACCES;
1365
1366        sp = smk_import(value, size);
1367        if (sp == NULL)
1368                return -EINVAL;
1369
1370        if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1371                nsp->smk_inode = sp;
1372                return 0;
1373        }
1374        /*
1375         * The rest of the Smack xattrs are only on sockets.
1376         */
1377        if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1378                return -EOPNOTSUPP;
1379
1380        sock = SOCKET_I(inode);
1381        if (sock == NULL || sock->sk == NULL)
1382                return -EOPNOTSUPP;
1383
1384        ssp = sock->sk->sk_security;
1385
1386        if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1387                ssp->smk_in = sp;
1388        else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1389                ssp->smk_out = sp;
1390                rc = smack_netlabel(sock->sk);
1391                if (rc != 0)
1392                        printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
1393                               __func__, -rc);
1394        } else
1395                return -EOPNOTSUPP;
1396
1397        return 0;
1398}
1399
1400/**
1401 * smack_socket_post_create - finish socket setup
1402 * @sock: the socket
1403 * @family: protocol family
1404 * @type: unused
1405 * @protocol: unused
1406 * @kern: unused
1407 *
1408 * Sets the netlabel information on the socket
1409 *
1410 * Returns 0 on success, and error code otherwise
1411 */
1412static int smack_socket_post_create(struct socket *sock, int family,
1413                                    int type, int protocol, int kern)
1414{
1415        if (family != PF_INET || sock->sk == NULL)
1416                return 0;
1417        /*
1418         * Set the outbound netlbl.
1419         */
1420        return smack_netlabel(sock->sk);
1421}
1422
1423/**
1424 * smack_flags_to_may - convert S_ to MAY_ values
1425 * @flags: the S_ value
1426 *
1427 * Returns the equivalent MAY_ value
1428 */
1429static int smack_flags_to_may(int flags)
1430{
1431        int may = 0;
1432
1433        if (flags & S_IRUGO)
1434                may |= MAY_READ;
1435        if (flags & S_IWUGO)
1436                may |= MAY_WRITE;
1437        if (flags & S_IXUGO)
1438                may |= MAY_EXEC;
1439
1440        return may;
1441}
1442
1443/**
1444 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
1445 * @msg: the object
1446 *
1447 * Returns 0
1448 */
1449static int smack_msg_msg_alloc_security(struct msg_msg *msg)
1450{
1451        msg->security = current->security;
1452        return 0;
1453}
1454
1455/**
1456 * smack_msg_msg_free_security - Clear the security blob for msg_msg
1457 * @msg: the object
1458 *
1459 * Clears the blob pointer
1460 */
1461static void smack_msg_msg_free_security(struct msg_msg *msg)
1462{
1463        msg->security = NULL;
1464}
1465
1466/**
1467 * smack_of_shm - the smack pointer for the shm
1468 * @shp: the object
1469 *
1470 * Returns a pointer to the smack value
1471 */
1472static char *smack_of_shm(struct shmid_kernel *shp)
1473{
1474        return (char *)shp->shm_perm.security;
1475}
1476
1477/**
1478 * smack_shm_alloc_security - Set the security blob for shm
1479 * @shp: the object
1480 *
1481 * Returns 0
1482 */
1483static int smack_shm_alloc_security(struct shmid_kernel *shp)
1484{
1485        struct kern_ipc_perm *isp = &shp->shm_perm;
1486
1487        isp->security = current->security;
1488        return 0;
1489}
1490
1491/**
1492 * smack_shm_free_security - Clear the security blob for shm
1493 * @shp: the object
1494 *
1495 * Clears the blob pointer
1496 */
1497static void smack_shm_free_security(struct shmid_kernel *shp)
1498{
1499        struct kern_ipc_perm *isp = &shp->shm_perm;
1500
1501        isp->security = NULL;
1502}
1503
1504/**
1505 * smack_shm_associate - Smack access check for shm
1506 * @shp: the object
1507 * @shmflg: access requested
1508 *
1509 * Returns 0 if current has the requested access, error code otherwise
1510 */
1511static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
1512{
1513        char *ssp = smack_of_shm(shp);
1514        int may;
1515
1516        may = smack_flags_to_may(shmflg);
1517        return smk_curacc(ssp, may);
1518}
1519
1520/**
1521 * smack_shm_shmctl - Smack access check for shm
1522 * @shp: the object
1523 * @cmd: what it wants to do
1524 *
1525 * Returns 0 if current has the requested access, error code otherwise
1526 */
1527static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
1528{
1529        char *ssp;
1530        int may;
1531
1532        switch (cmd) {
1533        case IPC_STAT:
1534        case SHM_STAT:
1535                may = MAY_READ;
1536                break;
1537        case IPC_SET:
1538        case SHM_LOCK:
1539        case SHM_UNLOCK:
1540        case IPC_RMID:
1541                may = MAY_READWRITE;
1542                break;
1543        case IPC_INFO:
1544        case SHM_INFO:
1545                /*
1546                 * System level information.
1547                 */
1548                return 0;
1549        default:
1550                return -EINVAL;
1551        }
1552
1553        ssp = smack_of_shm(shp);
1554        return smk_curacc(ssp, may);
1555}
1556
1557/**
1558 * smack_shm_shmat - Smack access for shmat
1559 * @shp: the object
1560 * @shmaddr: unused
1561 * @shmflg: access requested
1562 *
1563 * Returns 0 if current has the requested access, error code otherwise
1564 */
1565static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
1566                           int shmflg)
1567{
1568        char *ssp = smack_of_shm(shp);
1569        int may;
1570
1571        may = smack_flags_to_may(shmflg);
1572        return smk_curacc(ssp, may);
1573}
1574
1575/**
1576 * smack_of_sem - the smack pointer for the sem
1577 * @sma: the object
1578 *
1579 * Returns a pointer to the smack value
1580 */
1581static char *smack_of_sem(struct sem_array *sma)
1582{
1583        return (char *)sma->sem_perm.security;
1584}
1585
1586/**
1587 * smack_sem_alloc_security - Set the security blob for sem
1588 * @sma: the object
1589 *
1590 * Returns 0
1591 */
1592static int smack_sem_alloc_security(struct sem_array *sma)
1593{
1594        struct kern_ipc_perm *isp = &sma->sem_perm;
1595
1596        isp->security = current->security;
1597        return 0;
1598}
1599
1600/**
1601 * smack_sem_free_security - Clear the security blob for sem
1602 * @sma: the object
1603 *
1604 * Clears the blob pointer
1605 */
1606static void smack_sem_free_security(struct sem_array *sma)
1607{
1608        struct kern_ipc_perm *isp = &sma->sem_perm;
1609
1610        isp->security = NULL;
1611}
1612
1613/**
1614 * smack_sem_associate - Smack access check for sem
1615 * @sma: the object
1616 * @semflg: access requested
1617 *
1618 * Returns 0 if current has the requested access, error code otherwise
1619 */
1620static int smack_sem_associate(struct sem_array *sma, int semflg)
1621{
1622        char *ssp = smack_of_sem(sma);
1623        int may;
1624
1625        may = smack_flags_to_may(semflg);
1626        return smk_curacc(ssp, may);
1627}
1628
1629/**
1630 * smack_sem_shmctl - Smack access check for sem
1631 * @sma: the object
1632 * @cmd: what it wants to do
1633 *
1634 * Returns 0 if current has the requested access, error code otherwise
1635 */
1636static int smack_sem_semctl(struct sem_array *sma, int cmd)
1637{
1638        char *ssp;
1639        int may;
1640
1641        switch (cmd) {
1642        case GETPID:
1643        case GETNCNT:
1644        case GETZCNT:
1645        case GETVAL:
1646        case GETALL:
1647        case IPC_STAT:
1648        case SEM_STAT:
1649                may = MAY_READ;
1650                break;
1651        case SETVAL:
1652        case SETALL:
1653        case IPC_RMID:
1654        case IPC_SET:
1655                may = MAY_READWRITE;
1656                break;
1657        case IPC_INFO:
1658        case SEM_INFO:
1659                /*
1660                 * System level information
1661                 */
1662                return 0;
1663        default:
1664                return -EINVAL;
1665        }
1666
1667        ssp = smack_of_sem(sma);
1668        return smk_curacc(ssp, may);
1669}
1670
1671/**
1672 * smack_sem_semop - Smack checks of semaphore operations
1673 * @sma: the object
1674 * @sops: unused
1675 * @nsops: unused
1676 * @alter: unused
1677 *
1678 * Treated as read and write in all cases.
1679 *
1680 * Returns 0 if access is allowed, error code otherwise
1681 */
1682static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
1683                           unsigned nsops, int alter)
1684{
1685        char *ssp = smack_of_sem(sma);
1686
1687        return smk_curacc(ssp, MAY_READWRITE);
1688}
1689
1690/**
1691 * smack_msg_alloc_security - Set the security blob for msg
1692 * @msq: the object
1693 *
1694 * Returns 0
1695 */
1696static int smack_msg_queue_alloc_security(struct msg_queue *msq)
1697{
1698        struct kern_ipc_perm *kisp = &msq->q_perm;
1699
1700        kisp->security = current->security;
1701        return 0;
1702}
1703
1704/**
1705 * smack_msg_free_security - Clear the security blob for msg
1706 * @msq: the object
1707 *
1708 * Clears the blob pointer
1709 */
1710static void smack_msg_queue_free_security(struct msg_queue *msq)
1711{
1712        struct kern_ipc_perm *kisp = &msq->q_perm;
1713
1714        kisp->security = NULL;
1715}
1716
1717/**
1718 * smack_of_msq - the smack pointer for the msq
1719 * @msq: the object
1720 *
1721 * Returns a pointer to the smack value
1722 */
1723static char *smack_of_msq(struct msg_queue *msq)
1724{
1725        return (char *)msq->q_perm.security;
1726}
1727
1728/**
1729 * smack_msg_queue_associate - Smack access check for msg_queue
1730 * @msq: the object
1731 * @msqflg: access requested
1732 *
1733 * Returns 0 if current has the requested access, error code otherwise
1734 */
1735static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
1736{
1737        char *msp = smack_of_msq(msq);
1738        int may;
1739
1740        may = smack_flags_to_may(msqflg);
1741        return smk_curacc(msp, may);
1742}
1743
1744/**
1745 * smack_msg_queue_msgctl - Smack access check for msg_queue
1746 * @msq: the object
1747 * @cmd: what it wants to do
1748 *
1749 * Returns 0 if current has the requested access, error code otherwise
1750 */
1751static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
1752{
1753        char *msp;
1754        int may;
1755
1756        switch (cmd) {
1757        case IPC_STAT:
1758        case MSG_STAT:
1759                may = MAY_READ;
1760                break;
1761        case IPC_SET:
1762        case IPC_RMID:
1763                may = MAY_READWRITE;
1764                break;
1765        case IPC_INFO:
1766        case MSG_INFO:
1767                /*
1768                 * System level information
1769                 */
1770                return 0;
1771        default:
1772                return -EINVAL;
1773        }
1774
1775        msp = smack_of_msq(msq);
1776        return smk_curacc(msp, may);
1777}
1778
1779/**
1780 * smack_msg_queue_msgsnd - Smack access check for msg_queue
1781 * @msq: the object
1782 * @msg: unused
1783 * @msqflg: access requested
1784 *
1785 * Returns 0 if current has the requested access, error code otherwise
1786 */
1787static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
1788                                  int msqflg)
1789{
1790        char *msp = smack_of_msq(msq);
1791        int rc;
1792
1793        rc = smack_flags_to_may(msqflg);
1794        return smk_curacc(msp, rc);
1795}
1796
1797/**
1798 * smack_msg_queue_msgsnd - Smack access check for msg_queue
1799 * @msq: the object
1800 * @msg: unused
1801 * @target: unused
1802 * @type: unused
1803 * @mode: unused
1804 *
1805 * Returns 0 if current has read and write access, error code otherwise
1806 */
1807static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
1808                        struct task_struct *target, long type, int mode)
1809{
1810        char *msp = smack_of_msq(msq);
1811
1812        return smk_curacc(msp, MAY_READWRITE);
1813}
1814
1815/**
1816 * smack_ipc_permission - Smack access for ipc_permission()
1817 * @ipp: the object permissions
1818 * @flag: access requested
1819 *
1820 * Returns 0 if current has read and write access, error code otherwise
1821 */
1822static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
1823{
1824        char *isp = ipp->security;
1825        int may;
1826
1827        may = smack_flags_to_may(flag);
1828        return smk_curacc(isp, may);
1829}
1830
1831/**
1832 * smack_ipc_getsecid - Extract smack security id
1833 * @ipcp: the object permissions
1834 * @secid: where result will be saved
1835 */
1836static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
1837{
1838        char *smack = ipp->security;
1839
1840        *secid = smack_to_secid(smack);
1841}
1842
1843/**
1844 * smack_d_instantiate - Make sure the blob is correct on an inode
1845 * @opt_dentry: unused
1846 * @inode: the object
1847 *
1848 * Set the inode's security blob if it hasn't been done already.
1849 */
1850static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
1851{
1852        struct super_block *sbp;
1853        struct superblock_smack *sbsp;
1854        struct inode_smack *isp;
1855        char *csp = current->security;
1856        char *fetched;
1857        char *final;
1858        struct dentry *dp;
1859
1860        if (inode == NULL)
1861                return;
1862
1863        isp = inode->i_security;
1864
1865        mutex_lock(&isp->smk_lock);
1866        /*
1867         * If the inode is already instantiated
1868         * take the quick way out
1869         */
1870        if (isp->smk_flags & SMK_INODE_INSTANT)
1871                goto unlockandout;
1872
1873        sbp = inode->i_sb;
1874        sbsp = sbp->s_security;
1875        /*
1876         * We're going to use the superblock default label
1877         * if there's no label on the file.
1878         */
1879        final = sbsp->smk_default;
1880
1881        /*
1882         * If this is the root inode the superblock
1883         * may be in the process of initialization.
1884         * If that is the case use the root value out
1885         * of the superblock.
1886         */
1887        if (opt_dentry->d_parent == opt_dentry) {
1888                isp->smk_inode = sbsp->smk_root;
1889                isp->smk_flags |= SMK_INODE_INSTANT;
1890                goto unlockandout;
1891        }
1892
1893        /*
1894         * This is pretty hackish.
1895         * Casey says that we shouldn't have to do
1896         * file system specific code, but it does help
1897         * with keeping it simple.
1898         */
1899        switch (sbp->s_magic) {
1900        case SMACK_MAGIC:
1901                /*
1902                 * Casey says that it's a little embarassing
1903                 * that the smack file system doesn't do
1904                 * extended attributes.
1905                 */
1906                final = smack_known_star.smk_known;
1907                break;
1908        case PIPEFS_MAGIC:
1909                /*
1910                 * Casey says pipes are easy (?)
1911                 */
1912                final = smack_known_star.smk_known;
1913                break;
1914        case DEVPTS_SUPER_MAGIC:
1915                /*
1916                 * devpts seems content with the label of the task.
1917                 * Programs that change smack have to treat the
1918                 * pty with respect.
1919                 */
1920                final = csp;
1921                break;
1922        case SOCKFS_MAGIC:
1923                /*
1924                 * Casey says sockets get the smack of the task.
1925                 */
1926                final = csp;
1927                break;
1928        case PROC_SUPER_MAGIC:
1929                /*
1930                 * Casey says procfs appears not to care.
1931                 * The superblock default suffices.
1932                 */
1933                break;
1934        case TMPFS_MAGIC:
1935                /*
1936                 * Device labels should come from the filesystem,
1937                 * but watch out, because they're volitile,
1938                 * getting recreated on every reboot.
1939                 */
1940                final = smack_known_star.smk_known;
1941                /*
1942                 * No break.
1943                 *
1944                 * If a smack value has been set we want to use it,
1945                 * but since tmpfs isn't giving us the opportunity
1946                 * to set mount options simulate setting the
1947                 * superblock default.
1948                 */
1949        default:
1950                /*
1951                 * This isn't an understood special case.
1952                 * Get the value from the xattr.
1953                 *
1954                 * No xattr support means, alas, no SMACK label.
1955                 * Use the aforeapplied default.
1956                 * It would be curious if the label of the task
1957                 * does not match that assigned.
1958                 */
1959                if (inode->i_op->getxattr == NULL)
1960                        break;
1961                /*
1962                 * Get the dentry for xattr.
1963                 */
1964                if (opt_dentry == NULL) {
1965                        dp = d_find_alias(inode);
1966                        if (dp == NULL)
1967                                break;
1968                } else {
1969                        dp = dget(opt_dentry);
1970                        if (dp == NULL)
1971                                break;
1972                }
1973
1974                fetched = smk_fetch(inode, dp);
1975                if (fetched != NULL)
1976                        final = fetched;
1977
1978                dput(dp);
1979                break;
1980        }
1981
1982        if (final == NULL)
1983                isp->smk_inode = csp;
1984        else
1985                isp->smk_inode = final;
1986
1987        isp->smk_flags |= SMK_INODE_INSTANT;
1988
1989unlockandout:
1990        mutex_unlock(&isp->smk_lock);
1991        return;
1992}
1993
1994/**
1995 * smack_getprocattr - Smack process attribute access
1996 * @p: the object task
1997 * @name: the name of the attribute in /proc/.../attr
1998 * @value: where to put the result
1999 *
2000 * Places a copy of the task Smack into value
2001 *
2002 * Returns the length of the smack label or an error code
2003 */
2004static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2005{
2006        char *cp;
2007        int slen;
2008
2009        if (strcmp(name, "current") != 0)
2010                return -EINVAL;
2011
2012        cp = kstrdup(p->security, GFP_KERNEL);
2013        if (cp == NULL)
2014                return -ENOMEM;
2015
2016        slen = strlen(cp);
2017        *value = cp;
2018        return slen;
2019}
2020
2021/**
2022 * smack_setprocattr - Smack process attribute setting
2023 * @p: the object task
2024 * @name: the name of the attribute in /proc/.../attr
2025 * @value: the value to set
2026 * @size: the size of the value
2027 *
2028 * Sets the Smack value of the task. Only setting self
2029 * is permitted and only with privilege
2030 *
2031 * Returns the length of the smack label or an error code
2032 */
2033static int smack_setprocattr(struct task_struct *p, char *name,
2034                             void *value, size_t size)
2035{
2036        char *newsmack;
2037
2038        /*
2039         * Changing another process' Smack value is too dangerous
2040         * and supports no sane use case.
2041         */
2042        if (p != current)
2043                return -EPERM;
2044
2045        if (!capable(CAP_MAC_ADMIN))
2046                return -EPERM;
2047
2048        if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2049                return -EINVAL;
2050
2051        if (strcmp(name, "current") != 0)
2052                return -EINVAL;
2053
2054        newsmack = smk_import(value, size);
2055        if (newsmack == NULL)
2056                return -EINVAL;
2057
2058        p->security = newsmack;
2059        return size;
2060}
2061
2062/**
2063 * smack_unix_stream_connect - Smack access on UDS
2064 * @sock: one socket
2065 * @other: the other socket
2066 * @newsk: unused
2067 *
2068 * Return 0 if a subject with the smack of sock could access
2069 * an object with the smack of other, otherwise an error code
2070 */
2071static int smack_unix_stream_connect(struct socket *sock,
2072                                     struct socket *other, struct sock *newsk)
2073{
2074        struct inode *sp = SOCK_INODE(sock);
2075        struct inode *op = SOCK_INODE(other);
2076
2077        return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE);
2078}
2079
2080/**
2081 * smack_unix_may_send - Smack access on UDS
2082 * @sock: one socket
2083 * @other: the other socket
2084 *
2085 * Return 0 if a subject with the smack of sock could access
2086 * an object with the smack of other, otherwise an error code
2087 */
2088static int smack_unix_may_send(struct socket *sock, struct socket *other)
2089{
2090        struct inode *sp = SOCK_INODE(sock);
2091        struct inode *op = SOCK_INODE(other);
2092
2093        return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE);
2094}
2095
2096/**
2097 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat
2098 *      pair to smack
2099 * @sap: netlabel secattr
2100 * @sip: where to put the result
2101 *
2102 * Copies a smack label into sip
2103 */
2104static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2105{
2106        char smack[SMK_LABELLEN];
2107        int pcat;
2108
2109        if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) {
2110                /*
2111                 * If there are flags but no level netlabel isn't
2112                 * behaving the way we expect it to.
2113                 *
2114                 * Without guidance regarding the smack value
2115                 * for the packet fall back on the network
2116                 * ambient value.
2117                 */
2118                strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2119                return;
2120        }
2121        /*
2122         * Get the categories, if any
2123         */
2124        memset(smack, '\0', SMK_LABELLEN);
2125        if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2126                for (pcat = -1;;) {
2127                        pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat,
2128                                                          pcat + 1);
2129                        if (pcat < 0)
2130                                break;
2131                        smack_catset_bit(pcat, smack);
2132                }
2133        /*
2134         * If it is CIPSO using smack direct mapping
2135         * we are already done. WeeHee.
2136         */
2137        if (sap->attr.mls.lvl == smack_cipso_direct) {
2138                memcpy(sip, smack, SMK_MAXLEN);
2139                return;
2140        }
2141        /*
2142         * Look it up in the supplied table if it is not a direct mapping.
2143         */
2144        smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2145        return;
2146}
2147
2148/**
2149 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2150 * @sk: socket
2151 * @skb: packet
2152 *
2153 * Returns 0 if the packet should be delivered, an error code otherwise
2154 */
2155static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2156{
2157        struct netlbl_lsm_secattr secattr;
2158        struct socket_smack *ssp = sk->sk_security;
2159        char smack[SMK_LABELLEN];
2160        int rc;
2161
2162        if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2163                return 0;
2164
2165        /*
2166         * Translate what netlabel gave us.
2167         */
2168        memset(smack, '\0', SMK_LABELLEN);
2169        netlbl_secattr_init(&secattr);
2170        rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2171        if (rc == 0)
2172                smack_from_secattr(&secattr, smack);
2173        else
2174                strncpy(smack, smack_net_ambient, SMK_MAXLEN);
2175        netlbl_secattr_destroy(&secattr);
2176        /*
2177         * Receiving a packet requires that the other end
2178         * be able to write here. Read access is not required.
2179         * This is the simplist possible security model
2180         * for networking.
2181         */
2182        rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
2183        if (rc != 0)
2184                netlbl_skbuff_err(skb, rc, 0);
2185        return rc;
2186}
2187
2188/**
2189 * smack_socket_getpeersec_stream - pull in packet label
2190 * @sock: the socket
2191 * @optval: user's destination
2192 * @optlen: size thereof
2193 * @len: max thereoe
2194 *
2195 * returns zero on success, an error code otherwise
2196 */
2197static int smack_socket_getpeersec_stream(struct socket *sock,
2198                                          char __user *optval,
2199                                          int __user *optlen, unsigned len)
2200{
2201        struct socket_smack *ssp;
2202        int slen;
2203        int rc = 0;
2204
2205        ssp = sock->sk->sk_security;
2206        slen = strlen(ssp->smk_packet) + 1;
2207
2208        if (slen > len)
2209                rc = -ERANGE;
2210        else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2211                rc = -EFAULT;
2212
2213        if (put_user(slen, optlen) != 0)
2214                rc = -EFAULT;
2215
2216        return rc;
2217}
2218
2219
2220/**
2221 * smack_socket_getpeersec_dgram - pull in packet label
2222 * @sock: the socket
2223 * @skb: packet data
2224 * @secid: pointer to where to put the secid of the packet
2225 *
2226 * Sets the netlabel socket state on sk from parent
2227 */
2228static int smack_socket_getpeersec_dgram(struct socket *sock,
2229                                         struct sk_buff *skb, u32 *secid)
2230
2231{
2232        struct netlbl_lsm_secattr secattr;
2233        struct sock *sk;
2234        char smack[SMK_LABELLEN];
2235        int family = PF_INET;
2236        u32 s;
2237        int rc;
2238
2239        /*
2240         * Only works for families with packets.
2241         */
2242        if (sock != NULL) {
2243                sk = sock->sk;
2244                if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2245                        return 0;
2246                family = sk->sk_family;
2247        }
2248        /*
2249         * Translate what netlabel gave us.
2250         */
2251        memset(smack, '\0', SMK_LABELLEN);
2252        netlbl_secattr_init(&secattr);
2253        rc = netlbl_skbuff_getattr(skb, family, &secattr);
2254        if (rc == 0)
2255                smack_from_secattr(&secattr, smack);
2256        netlbl_secattr_destroy(&secattr);
2257
2258        /*
2259         * Give up if we couldn't get anything
2260         */
2261        if (rc != 0)
2262                return rc;
2263
2264        s = smack_to_secid(smack);
2265        if (s == 0)
2266                return -EINVAL;
2267
2268        *secid = s;
2269        return 0;
2270}
2271
2272/**
2273 * smack_sock_graft - graft access state between two sockets
2274 * @sk: fresh sock
2275 * @parent: donor socket
2276 *
2277 * Sets the netlabel socket state on sk from parent
2278 */
2279static void smack_sock_graft(struct sock *sk, struct socket *parent)
2280{
2281        struct socket_smack *ssp;
2282        int rc;
2283
2284        if (sk == NULL)
2285                return;
2286
2287        if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2288                return;
2289
2290        ssp = sk->sk_security;
2291        ssp->smk_in = current->security;
2292        ssp->smk_out = current->security;
2293        ssp->smk_packet[0] = '\0';
2294
2295        rc = smack_netlabel(sk);
2296        if (rc != 0)
2297                printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
2298                       __func__, -rc);
2299}
2300
2301/**
2302 * smack_inet_conn_request - Smack access check on connect
2303 * @sk: socket involved
2304 * @skb: packet
2305 * @req: unused
2306 *
2307 * Returns 0 if a task with the packet label could write to
2308 * the socket, otherwise an error code
2309 */
2310static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
2311                                   struct request_sock *req)
2312{
2313        struct netlbl_lsm_secattr skb_secattr;
2314        struct socket_smack *ssp = sk->sk_security;
2315        char smack[SMK_LABELLEN];
2316        int rc;
2317
2318        if (skb == NULL)
2319                return -EACCES;
2320
2321        memset(smack, '\0', SMK_LABELLEN);
2322        netlbl_secattr_init(&skb_secattr);
2323        rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr);
2324        if (rc == 0)
2325                smack_from_secattr(&skb_secattr, smack);
2326        else
2327                strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
2328        netlbl_secattr_destroy(&skb_secattr);
2329        /*
2330         * Receiving a packet requires that the other end
2331         * be able to write here. Read access is not required.
2332         *
2333         * If the request is successful save the peer's label
2334         * so that SO_PEERCRED can report it.
2335         */
2336        rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
2337        if (rc == 0)
2338                strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
2339
2340        return rc;
2341}
2342
2343/*
2344 * Key management security hooks
2345 *
2346 * Casey has not tested key support very heavily.
2347 * The permission check is most likely too restrictive.
2348 * If you care about keys please have a look.
2349 */
2350#ifdef CONFIG_KEYS
2351
2352/**
2353 * smack_key_alloc - Set the key security blob
2354 * @key: object
2355 * @tsk: the task associated with the key
2356 * @flags: unused
2357 *
2358 * No allocation required
2359 *
2360 * Returns 0
2361 */
2362static int smack_key_alloc(struct key *key, struct task_struct *tsk,
2363                           unsigned long flags)
2364{
2365        key->security = tsk->security;
2366        return 0;
2367}
2368
2369/**
2370 * smack_key_free - Clear the key security blob
2371 * @key: the object
2372 *
2373 * Clear the blob pointer
2374 */
2375static void smack_key_free(struct key *key)
2376{
2377        key->security = NULL;
2378}
2379
2380/*
2381 * smack_key_permission - Smack access on a key
2382 * @key_ref: gets to the object
2383 * @context: task involved
2384 * @perm: unused
2385 *
2386 * Return 0 if the task has read and write to the object,
2387 * an error code otherwise
2388 */
2389static int smack_key_permission(key_ref_t key_ref,
2390                                struct task_struct *context, key_perm_t perm)
2391{
2392        struct key *keyp;
2393
2394        keyp = key_ref_to_ptr(key_ref);
2395        if (keyp == NULL)
2396                return -EINVAL;
2397        /*
2398         * If the key hasn't been initialized give it access so that
2399         * it may do so.
2400         */
2401        if (keyp->security == NULL)
2402                return 0;
2403        /*
2404         * This should not occur
2405         */
2406        if (context->security == NULL)
2407                return -EACCES;
2408
2409        return smk_access(context->security, keyp->security, MAY_READWRITE);
2410}
2411#endif /* CONFIG_KEYS */
2412
2413/*
2414 * Smack Audit hooks
2415 *
2416 * Audit requires a unique representation of each Smack specific
2417 * rule. This unique representation is used to distinguish the
2418 * object to be audited from remaining kernel objects and also
2419 * works as a glue between the audit hooks.
2420 *
2421 * Since repository entries are added but never deleted, we'll use
2422 * the smack_known label address related to the given audit rule as
2423 * the needed unique representation. This also better fits the smack
2424 * model where nearly everything is a label.
2425 */
2426#ifdef CONFIG_AUDIT
2427
2428/**
2429 * smack_audit_rule_init - Initialize a smack audit rule
2430 * @field: audit rule fields given from user-space (audit.h)
2431 * @op: required testing operator (=, !=, >, <, ...)
2432 * @rulestr: smack label to be audited
2433 * @vrule: pointer to save our own audit rule representation
2434 *
2435 * Prepare to audit cases where (@field @op @rulestr) is true.
2436 * The label to be audited is created if necessay.
2437 */
2438static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
2439{
2440        char **rule = (char **)vrule;
2441        *rule = NULL;
2442
2443        if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2444                return -EINVAL;
2445
2446        if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
2447                return -EINVAL;
2448
2449        *rule = smk_import(rulestr, 0);
2450
2451        return 0;
2452}
2453
2454/**
2455 * smack_audit_rule_known - Distinguish Smack audit rules
2456 * @krule: rule of interest, in Audit kernel representation format
2457 *
2458 * This is used to filter Smack rules from remaining Audit ones.
2459 * If it's proved that this rule belongs to us, the
2460 * audit_rule_match hook will be called to do the final judgement.
2461 */
2462static int smack_audit_rule_known(struct audit_krule *krule)
2463{
2464        struct audit_field *f;
2465        int i;
2466
2467        for (i = 0; i < krule->field_count; i++) {
2468                f = &krule->fields[i];
2469
2470                if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
2471                        return 1;
2472        }
2473
2474        return 0;
2475}
2476
2477/**
2478 * smack_audit_rule_match - Audit given object ?
2479 * @secid: security id for identifying the object to test
2480 * @field: audit rule flags given from user-space
2481 * @op: required testing operator
2482 * @vrule: smack internal rule presentation
2483 * @actx: audit context associated with the check
2484 *
2485 * The core Audit hook. It's used to take the decision of
2486 * whether to audit or not to audit a given object.
2487 */
2488static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
2489                                  struct audit_context *actx)
2490{
2491        char *smack;
2492        char *rule = vrule;
2493
2494        if (!rule) {
2495                audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
2496                          "Smack: missing rule\n");
2497                return -ENOENT;
2498        }
2499
2500        if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
2501                return 0;
2502
2503        smack = smack_from_secid(secid);
2504
2505        /*
2506         * No need to do string comparisons. If a match occurs,
2507         * both pointers will point to the same smack_known
2508         * label.
2509         */
2510        if (op == AUDIT_EQUAL)
2511                return (rule == smack);
2512        if (op == AUDIT_NOT_EQUAL)
2513                return (rule != smack);
2514
2515        return 0;
2516}
2517
2518/**
2519 * smack_audit_rule_free - free smack rule representation
2520 * @vrule: rule to be freed.
2521 *
2522 * No memory was allocated.
2523 */
2524static void smack_audit_rule_free(void *vrule)
2525{
2526        /* No-op */
2527}
2528
2529#endif /* CONFIG_AUDIT */
2530
2531/*
2532 * smack_secid_to_secctx - return the smack label for a secid
2533 * @secid: incoming integer
2534 * @secdata: destination
2535 * @seclen: how long it is
2536 *
2537 * Exists for networking code.
2538 */
2539static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
2540{
2541        char *sp = smack_from_secid(secid);
2542
2543        *secdata = sp;
2544        *seclen = strlen(sp);
2545        return 0;
2546}
2547
2548/*
2549 * smack_secctx_to_secid - return the secid for a smack label
2550 * @secdata: smack label
2551 * @seclen: how long result is
2552 * @secid: outgoing integer
2553 *
2554 * Exists for audit and networking code.
2555 */
2556static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
2557{
2558        *secid = smack_to_secid(secdata);
2559        return 0;
2560}
2561
2562/*
2563 * smack_release_secctx - don't do anything.
2564 * @key_ref: unused
2565 * @context: unused
2566 * @perm: unused
2567 *
2568 * Exists to make sure nothing gets done, and properly
2569 */
2570static void smack_release_secctx(char *secdata, u32 seclen)
2571{
2572}
2573
2574struct security_operations smack_ops = {
2575        .name =                         "smack",
2576
2577        .ptrace_may_access =            smack_ptrace_may_access,
2578        .ptrace_traceme =               smack_ptrace_traceme,
2579        .capget =                       cap_capget,
2580        .capset_check =                 cap_capset_check,
2581        .capset_set =                   cap_capset_set,
2582        .capable =                      cap_capable,
2583        .syslog =                       smack_syslog,
2584        .settime =                      cap_settime,
2585        .vm_enough_memory =             cap_vm_enough_memory,
2586
2587        .bprm_apply_creds =             cap_bprm_apply_creds,
2588        .bprm_set_security =            cap_bprm_set_security,
2589        .bprm_secureexec =              cap_bprm_secureexec,
2590
2591        .sb_alloc_security =            smack_sb_alloc_security,
2592        .sb_free_security =             smack_sb_free_security,
2593        .sb_copy_data =                 smack_sb_copy_data,
2594        .sb_kern_mount =                smack_sb_kern_mount,
2595        .sb_statfs =                    smack_sb_statfs,
2596        .sb_mount =                     smack_sb_mount,
2597        .sb_umount =                    smack_sb_umount,
2598
2599        .inode_alloc_security =         smack_inode_alloc_security,
2600        .inode_free_security =          smack_inode_free_security,
2601        .inode_init_security =          smack_inode_init_security,
2602        .inode_link =                   smack_inode_link,
2603        .inode_unlink =                 smack_inode_unlink,
2604        .inode_rmdir =                  smack_inode_rmdir,
2605        .inode_rename =                 smack_inode_rename,
2606        .inode_permission =             smack_inode_permission,
2607        .inode_setattr =                smack_inode_setattr,
2608        .inode_getattr =                smack_inode_getattr,
2609        .inode_setxattr =               smack_inode_setxattr,
2610        .inode_post_setxattr =          smack_inode_post_setxattr,
2611        .inode_getxattr =               smack_inode_getxattr,
2612        .inode_removexattr =            smack_inode_removexattr,
2613        .inode_need_killpriv =          cap_inode_need_killpriv,
2614        .inode_killpriv =               cap_inode_killpriv,
2615        .inode_getsecurity =            smack_inode_getsecurity,
2616        .inode_setsecurity =            smack_inode_setsecurity,
2617        .inode_listsecurity =           smack_inode_listsecurity,
2618        .inode_getsecid =               smack_inode_getsecid,
2619
2620        .file_permission =              smack_file_permission,
2621        .file_alloc_security =          smack_file_alloc_security,
2622        .file_free_security =           smack_file_free_security,
2623        .file_ioctl =                   smack_file_ioctl,
2624        .file_lock =                    smack_file_lock,
2625        .file_fcntl =                   smack_file_fcntl,
2626        .file_set_fowner =              smack_file_set_fowner,
2627        .file_send_sigiotask =          smack_file_send_sigiotask,
2628        .file_receive =                 smack_file_receive,
2629
2630        .task_alloc_security =          smack_task_alloc_security,
2631        .task_free_security =           smack_task_free_security,
2632        .task_post_setuid =             cap_task_post_setuid,
2633        .task_setpgid =                 smack_task_setpgid,
2634        .task_getpgid =                 smack_task_getpgid,
2635        .task_getsid =                  smack_task_getsid,
2636        .task_getsecid =                smack_task_getsecid,
2637        .task_setnice =                 smack_task_setnice,
2638        .task_setioprio =               smack_task_setioprio,
2639        .task_getioprio =               smack_task_getioprio,
2640        .task_setscheduler =            smack_task_setscheduler,
2641        .task_getscheduler =            smack_task_getscheduler,
2642        .task_movememory =              smack_task_movememory,
2643        .task_kill =                    smack_task_kill,
2644        .task_wait =                    smack_task_wait,
2645        .task_reparent_to_init =        cap_task_reparent_to_init,
2646        .task_to_inode =                smack_task_to_inode,
2647        .task_prctl =                   cap_task_prctl,
2648
2649        .ipc_permission =               smack_ipc_permission,
2650        .ipc_getsecid =                 smack_ipc_getsecid,
2651
2652        .msg_msg_alloc_security =       smack_msg_msg_alloc_security,
2653        .msg_msg_free_security =        smack_msg_msg_free_security,
2654
2655        .msg_queue_alloc_security =     smack_msg_queue_alloc_security,
2656        .msg_queue_free_security =      smack_msg_queue_free_security,
2657        .msg_queue_associate =          smack_msg_queue_associate,
2658        .msg_queue_msgctl =             smack_msg_queue_msgctl,
2659        .msg_queue_msgsnd =             smack_msg_queue_msgsnd,
2660        .msg_queue_msgrcv =             smack_msg_queue_msgrcv,
2661
2662        .shm_alloc_security =           smack_shm_alloc_security,
2663        .shm_free_security =            smack_shm_free_security,
2664        .shm_associate =                smack_shm_associate,
2665        .shm_shmctl =                   smack_shm_shmctl,
2666        .shm_shmat =                    smack_shm_shmat,
2667
2668        .sem_alloc_security =           smack_sem_alloc_security,
2669        .sem_free_security =            smack_sem_free_security,
2670        .sem_associate =                smack_sem_associate,
2671        .sem_semctl =                   smack_sem_semctl,
2672        .sem_semop =                    smack_sem_semop,
2673
2674        .netlink_send =                 cap_netlink_send,
2675        .netlink_recv =                 cap_netlink_recv,
2676
2677        .d_instantiate =                smack_d_instantiate,
2678
2679        .getprocattr =                  smack_getprocattr,
2680        .setprocattr =                  smack_setprocattr,
2681
2682        .unix_stream_connect =          smack_unix_stream_connect,
2683        .unix_may_send =                smack_unix_may_send,
2684
2685        .socket_post_create =           smack_socket_post_create,
2686        .socket_sock_rcv_skb =          smack_socket_sock_rcv_skb,
2687        .socket_getpeersec_stream =     smack_socket_getpeersec_stream,
2688        .socket_getpeersec_dgram =      smack_socket_getpeersec_dgram,
2689        .sk_alloc_security =            smack_sk_alloc_security,
2690        .sk_free_security =             smack_sk_free_security,
2691        .sock_graft =                   smack_sock_graft,
2692        .inet_conn_request =            smack_inet_conn_request,
2693
2694 /* key management security hooks */
2695#ifdef CONFIG_KEYS
2696        .key_alloc =                    smack_key_alloc,
2697        .key_free =                     smack_key_free,
2698        .key_permission =               smack_key_permission,
2699#endif /* CONFIG_KEYS */
2700
2701 /* Audit hooks */
2702#ifdef CONFIG_AUDIT
2703        .audit_rule_init =              smack_audit_rule_init,
2704        .audit_rule_known =             smack_audit_rule_known,
2705        .audit_rule_match =             smack_audit_rule_match,
2706        .audit_rule_free =              smack_audit_rule_free,
2707#endif /* CONFIG_AUDIT */
2708
2709        .secid_to_secctx =              smack_secid_to_secctx,
2710        .secctx_to_secid =              smack_secctx_to_secid,
2711        .release_secctx =               smack_release_secctx,
2712};
2713
2714/**
2715 * smack_init - initialize the smack system
2716 *
2717 * Returns 0
2718 */
2719static __init int smack_init(void)
2720{
2721        if (!security_module_enable(&smack_ops))
2722                return 0;
2723
2724        printk(KERN_INFO "Smack:  Initializing.\n");
2725
2726        /*
2727         * Set the security state for the initial task.
2728         */
2729        current->security = &smack_known_floor.smk_known;
2730
2731        /*
2732         * Initialize locks
2733         */
2734        spin_lock_init(&smack_known_unset.smk_cipsolock);
2735        spin_lock_init(&smack_known_huh.smk_cipsolock);
2736        spin_lock_init(&smack_known_hat.smk_cipsolock);
2737        spin_lock_init(&smack_known_star.smk_cipsolock);
2738        spin_lock_init(&smack_known_floor.smk_cipsolock);
2739        spin_lock_init(&smack_known_invalid.smk_cipsolock);
2740
2741        /*
2742         * Register with LSM
2743         */
2744        if (register_security(&smack_ops))
2745                panic("smack: Unable to register with kernel.\n");
2746
2747        return 0;
2748}
2749
2750/*
2751 * Smack requires early initialization in order to label
2752 * all processes and objects when they are created.
2753 */
2754security_initcall(smack_init);
2755