security/selinux/selinuxfs.c

   1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
   2  *
   3  *      Added conditional policy language extensions
   4  *
   5  *  Updated: Hewlett-Packard <paul@paul-moore.com>
   6  *
   7  *      Added support for the policy capability bitmap
   8  *
   9  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  10  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  11  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  12  *      This program is free software; you can redistribute it and/or modify
  13  *      it under the terms of the GNU General Public License as published by
  14  *      the Free Software Foundation, version 2.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/slab.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/fs.h>
  22 #include <linux/mutex.h>
  23 #include <linux/init.h>
  24 #include <linux/string.h>
  25 #include <linux/security.h>
  26 #include <linux/major.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/percpu.h>
  29 #include <linux/audit.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/kobject.h>
  32 #include <linux/ctype.h>
  33
  34 /* selinuxfs pseudo filesystem for exporting the security policy API.
  35    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  36
  37 #include "flask.h"
  38 #include "avc.h"
  39 #include "avc_ss.h"
  40 #include "security.h"
  41 #include "objsec.h"
  42 #include "conditional.h"
  43
  44 /* Policy capability filenames */
  45 static char *policycap_names[] = {
  46         "network_peer_controls",
  47         "open_perms"
  48 };
  49
  50 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  51
  52 static int __init checkreqprot_setup(char *str)
  53 {
  54         unsigned long checkreqprot;
  55         if (!strict_strtoul(str, 0, &checkreqprot))
  56                 selinux_checkreqprot = checkreqprot ? 1 : 0;
  57         return 1;
  58 }
  59 __setup("checkreqprot=", checkreqprot_setup);
  60
  61 static DEFINE_MUTEX(sel_mutex);
  62
  63 /* global data for booleans */
  64 static struct dentry *bool_dir;
  65 static int bool_num;
  66 static char **bool_pending_names;
  67 static int *bool_pending_values;
  68
  69 /* global data for classes */
  70 static struct dentry *class_dir;
  71 static unsigned long last_class_ino;
  72
  73 static char policy_opened;
  74
  75 /* global data for policy capabilities */
  76 static struct dentry *policycap_dir;
  77
  78 /* Check whether a task is allowed to use a security operation. */
  79 static int task_has_security(struct task_struct *tsk,
  80                              u32 perms)
  81 {
  82         const struct task_security_struct *tsec;
  83         u32 sid = 0;
  84
  85         rcu_read_lock();
  86         tsec = __task_cred(tsk)->security;
  87         if (tsec)
  88                 sid = tsec->sid;
  89         rcu_read_unlock();
  90         if (!tsec)
  91                 return -EACCES;
  92
  93         return avc_has_perm(sid, SECINITSID_SECURITY,
  94                             SECCLASS_SECURITY, perms, NULL);
  95 }
  96
  97 enum sel_inos {
  98         SEL_ROOT_INO = 2,
  99         SEL_LOAD,       /* load policy */
 100         SEL_ENFORCE,    /* get or set enforcing status */
 101         SEL_CONTEXT,    /* validate context */
 102         SEL_ACCESS,     /* compute access decision */
 103         SEL_CREATE,     /* compute create labeling decision */
 104         SEL_RELABEL,    /* compute relabeling decision */
 105         SEL_USER,       /* compute reachable user contexts */
 106         SEL_POLICYVERS, /* return policy version for this kernel */
 107         SEL_COMMIT_BOOLS, /* commit new boolean values */
 108         SEL_MLS,        /* return if MLS policy is enabled */
 109         SEL_DISABLE,    /* disable SELinux until next reboot */
 110         SEL_MEMBER,     /* compute polyinstantiation membership decision */
 111         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 112         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 113         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
 114         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 115         SEL_STATUS,     /* export current status using mmap() */
 116         SEL_POLICY,     /* allow userspace to read the in kernel policy */
 117         SEL_INO_NEXT,   /* The next inode number to use */
 118 };
 119
 120 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 121
 122 #define SEL_INITCON_INO_OFFSET          0x01000000
 123 #define SEL_BOOL_INO_OFFSET             0x02000000
 124 #define SEL_CLASS_INO_OFFSET            0x04000000
 125 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
 126 #define SEL_INO_MASK                    0x00ffffff
 127
 128 #define TMPBUFLEN       12
 129 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 130                                 size_t count, loff_t *ppos)
 131 {
 132         char tmpbuf[TMPBUFLEN];
 133         ssize_t length;
 134
 135         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 136         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 137 }
 138
 139 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 140 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 141                                  size_t count, loff_t *ppos)
 142
 143 {
 144         char *page = NULL;
 145         ssize_t length;
 146         int new_value;
 147
 148         length = -ENOMEM;
 149         if (count >= PAGE_SIZE)
 150                 goto out;
 151
 152         /* No partial writes. */
 153         length = EINVAL;
 154         if (*ppos != 0)
 155                 goto out;
 156
 157         length = -ENOMEM;
 158         page = (char *)get_zeroed_page(GFP_KERNEL);
 159         if (!page)
 160                 goto out;
 161
 162         length = -EFAULT;
 163         if (copy_from_user(page, buf, count))
 164                 goto out;
 165
 166         length = -EINVAL;
 167         if (sscanf(page, "%d", &new_value) != 1)
 168                 goto out;
 169
 170         if (new_value != selinux_enforcing) {
 171                 length = task_has_security(current, SECURITY__SETENFORCE);
 172                 if (length)
 173                         goto out;
 174                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 175                         "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 176                         new_value, selinux_enforcing,
 177                         audit_get_loginuid(current),
 178                         audit_get_sessionid(current));
 179                 selinux_enforcing = new_value;
 180                 if (selinux_enforcing)
 181                         avc_ss_reset(0);
 182                 selnl_notify_setenforce(selinux_enforcing);
 183                 selinux_status_update_setenforce(selinux_enforcing);
 184         }
 185         length = count;
 186 out:
 187         free_page((unsigned long) page);
 188         return length;
 189 }
 190 #else
 191 #define sel_write_enforce NULL
 192 #endif
 193
 194 static const struct file_operations sel_enforce_ops = {
 195         .read           = sel_read_enforce,
 196         .write          = sel_write_enforce,
 197         .llseek         = generic_file_llseek,
 198 };
 199
 200 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 201                                         size_t count, loff_t *ppos)
 202 {
 203         char tmpbuf[TMPBUFLEN];
 204         ssize_t length;
 205         ino_t ino = filp->f_path.dentry->d_inode->i_ino;
 206         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 207                 security_get_reject_unknown() : !security_get_allow_unknown();
 208
 209         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 210         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 211 }
 212
 213 static const struct file_operations sel_handle_unknown_ops = {
 214         .read           = sel_read_handle_unknown,
 215         .llseek         = generic_file_llseek,
 216 };
 217
 218 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 219 {
 220         struct page    *status = selinux_kernel_status_page();
 221
 222         if (!status)
 223                 return -ENOMEM;
 224
 225         filp->private_data = status;
 226
 227         return 0;
 228 }
 229
 230 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 231                                       size_t count, loff_t *ppos)
 232 {
 233         struct page    *status = filp->private_data;
 234
 235         BUG_ON(!status);
 236
 237         return simple_read_from_buffer(buf, count, ppos,
 238                                        page_address(status),
 239                                        sizeof(struct selinux_kernel_status));
 240 }
 241
 242 static int sel_mmap_handle_status(struct file *filp,
 243                                   struct vm_area_struct *vma)
 244 {
 245         struct page    *status = filp->private_data;
 246         unsigned long   size = vma->vm_end - vma->vm_start;
 247
 248         BUG_ON(!status);
 249
 250         /* only allows one page from the head */
 251         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 252                 return -EIO;
 253         /* disallow writable mapping */
 254         if (vma->vm_flags & VM_WRITE)
 255                 return -EPERM;
 256         /* disallow mprotect() turns it into writable */
 257         vma->vm_flags &= ~VM_MAYWRITE;
 258
 259         return remap_pfn_range(vma, vma->vm_start,
 260                                page_to_pfn(status),
 261                                size, vma->vm_page_prot);
 262 }
 263
 264 static const struct file_operations sel_handle_status_ops = {
 265         .open           = sel_open_handle_status,
 266         .read           = sel_read_handle_status,
 267         .mmap           = sel_mmap_handle_status,
 268         .llseek         = generic_file_llseek,
 269 };
 270
 271 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 272 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 273                                  size_t count, loff_t *ppos)
 274
 275 {
 276         char *page = NULL;
 277         ssize_t length;
 278         int new_value;
 279
 280         length = -ENOMEM;
 281         if (count >= PAGE_SIZE)
 282                 goto out;
 283
 284         /* No partial writes. */
 285         length = -EINVAL;
 286         if (*ppos != 0)
 287                 goto out;
 288
 289         length = -ENOMEM;
 290         page = (char *)get_zeroed_page(GFP_KERNEL);
 291         if (!page)
 292                 goto out;
 293
 294         length = -EFAULT;
 295         if (copy_from_user(page, buf, count))
 296                 goto out;
 297
 298         length = -EINVAL;
 299         if (sscanf(page, "%d", &new_value) != 1)
 300                 goto out;
 301
 302         if (new_value) {
 303                 length = selinux_disable();
 304                 if (length)
 305                         goto out;
 306                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 307                         "selinux=0 auid=%u ses=%u",
 308                         audit_get_loginuid(current),
 309                         audit_get_sessionid(current));
 310         }
 311
 312         length = count;
 313 out:
 314         free_page((unsigned long) page);
 315         return length;
 316 }
 317 #else
 318 #define sel_write_disable NULL
 319 #endif
 320
 321 static const struct file_operations sel_disable_ops = {
 322         .write          = sel_write_disable,
 323         .llseek         = generic_file_llseek,
 324 };
 325
 326 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 327                                    size_t count, loff_t *ppos)
 328 {
 329         char tmpbuf[TMPBUFLEN];
 330         ssize_t length;
 331
 332         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 333         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 334 }
 335
 336 static const struct file_operations sel_policyvers_ops = {
 337         .read           = sel_read_policyvers,
 338         .llseek         = generic_file_llseek,
 339 };
 340
 341 /* declaration for sel_write_load */
 342 static int sel_make_bools(void);
 343 static int sel_make_classes(void);
 344 static int sel_make_policycap(void);
 345
 346 /* declaration for sel_make_class_dirs */
 347 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
 348                         unsigned long *ino);
 349
 350 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 351                                 size_t count, loff_t *ppos)
 352 {
 353         char tmpbuf[TMPBUFLEN];
 354         ssize_t length;
 355
 356         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 357                            security_mls_enabled());
 358         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 359 }
 360
 361 static const struct file_operations sel_mls_ops = {
 362         .read           = sel_read_mls,
 363         .llseek         = generic_file_llseek,
 364 };
 365
 366 struct policy_load_memory {
 367         size_t len;
 368         void *data;
 369 };
 370
 371 static int sel_open_policy(struct inode *inode, struct file *filp)
 372 {
 373         struct policy_load_memory *plm = NULL;
 374         int rc;
 375
 376         BUG_ON(filp->private_data);
 377
 378         mutex_lock(&sel_mutex);
 379
 380         rc = task_has_security(current, SECURITY__READ_POLICY);
 381         if (rc)
 382                 goto err;
 383
 384         rc = -EBUSY;
 385         if (policy_opened)
 386                 goto err;
 387
 388         rc = -ENOMEM;
 389         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 390         if (!plm)
 391                 goto err;
 392
 393         if (i_size_read(inode) != security_policydb_len()) {
 394                 mutex_lock(&inode->i_mutex);
 395                 i_size_write(inode, security_policydb_len());
 396                 mutex_unlock(&inode->i_mutex);
 397         }
 398
 399         rc = security_read_policy(&plm->data, &plm->len);
 400         if (rc)
 401                 goto err;
 402
 403         policy_opened = 1;
 404
 405         filp->private_data = plm;
 406
 407         mutex_unlock(&sel_mutex);
 408
 409         return 0;
 410 err:
 411         mutex_unlock(&sel_mutex);
 412
 413         if (plm)
 414                 vfree(plm->data);
 415         kfree(plm);
 416         return rc;
 417 }
 418
 419 static int sel_release_policy(struct inode *inode, struct file *filp)
 420 {
 421         struct policy_load_memory *plm = filp->private_data;
 422
 423         BUG_ON(!plm);
 424
 425         policy_opened = 0;
 426
 427         vfree(plm->data);
 428         kfree(plm);
 429
 430         return 0;
 431 }
 432
 433 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 434                                size_t count, loff_t *ppos)
 435 {
 436         struct policy_load_memory *plm = filp->private_data;
 437         int ret;
 438
 439         mutex_lock(&sel_mutex);
 440
 441         ret = task_has_security(current, SECURITY__READ_POLICY);
 442         if (ret)
 443                 goto out;
 444
 445         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 446 out:
 447         mutex_unlock(&sel_mutex);
 448         return ret;
 449 }
 450
 451 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 452                                  struct vm_fault *vmf)
 453 {
 454         struct policy_load_memory *plm = vma->vm_file->private_data;
 455         unsigned long offset;
 456         struct page *page;
 457
 458         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 459                 return VM_FAULT_SIGBUS;
 460
 461         offset = vmf->pgoff << PAGE_SHIFT;
 462         if (offset >= roundup(plm->len, PAGE_SIZE))
 463                 return VM_FAULT_SIGBUS;
 464
 465         page = vmalloc_to_page(plm->data + offset);
 466         get_page(page);
 467
 468         vmf->page = page;
 469
 470         return 0;
 471 }
 472
 473 static struct vm_operations_struct sel_mmap_policy_ops = {
 474         .fault = sel_mmap_policy_fault,
 475         .page_mkwrite = sel_mmap_policy_fault,
 476 };
 477
 478 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 479 {
 480         if (vma->vm_flags & VM_SHARED) {
 481                 /* do not allow mprotect to make mapping writable */
 482                 vma->vm_flags &= ~VM_MAYWRITE;
 483
 484                 if (vma->vm_flags & VM_WRITE)
 485                         return -EACCES;
 486         }
 487
 488         vma->vm_flags |= VM_RESERVED;
 489         vma->vm_ops = &sel_mmap_policy_ops;
 490
 491         return 0;
 492 }
 493
 494 static const struct file_operations sel_policy_ops = {
 495         .open           = sel_open_policy,
 496         .read           = sel_read_policy,
 497         .mmap           = sel_mmap_policy,
 498         .release        = sel_release_policy,
 499 };
 500
 501 static ssize_t sel_write_load(struct file *file, const char __user *buf,
 502                               size_t count, loff_t *ppos)
 503
 504 {
 505         ssize_t length;
 506         void *data = NULL;
 507
 508         mutex_lock(&sel_mutex);
 509
 510         length = task_has_security(current, SECURITY__LOAD_POLICY);
 511         if (length)
 512                 goto out;
 513
 514         /* No partial writes. */
 515         length = -EINVAL;
 516         if (*ppos != 0)
 517                 goto out;
 518
 519         length = -EFBIG;
 520         if (count > 64 * 1024 * 1024)
 521                 goto out;
 522
 523         length = -ENOMEM;
 524         data = vmalloc(count);
 525         if (!data)
 526                 goto out;
 527
 528         length = -EFAULT;
 529         if (copy_from_user(data, buf, count) != 0)
 530                 goto out;
 531
 532         length = security_load_policy(data, count);
 533         if (length)
 534                 goto out;
 535
 536         length = sel_make_bools();
 537         if (length)
 538                 goto out1;
 539
 540         length = sel_make_classes();
 541         if (length)
 542                 goto out1;
 543
 544         length = sel_make_policycap();
 545         if (length)
 546                 goto out1;
 547
 548         length = count;
 549
 550 out1:
 551         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 552                 "policy loaded auid=%u ses=%u",
 553                 audit_get_loginuid(current),
 554                 audit_get_sessionid(current));
 555 out:
 556         mutex_unlock(&sel_mutex);
 557         vfree(data);
 558         return length;
 559 }
 560
 561 static const struct file_operations sel_load_ops = {
 562         .write          = sel_write_load,
 563         .llseek         = generic_file_llseek,
 564 };
 565
 566 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 567 {
 568         char *canon = NULL;
 569         u32 sid, len;
 570         ssize_t length;
 571
 572         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 573         if (length)
 574                 goto out;
 575
 576         length = security_context_to_sid(buf, size, &sid);
 577         if (length)
 578                 goto out;
 579
 580         length = security_sid_to_context(sid, &canon, &len);
 581         if (length)
 582                 goto out;
 583
 584         length = -ERANGE;
 585         if (len > SIMPLE_TRANSACTION_LIMIT) {
 586                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 587                         "payload max\n", __func__, len);
 588                 goto out;
 589         }
 590
 591         memcpy(buf, canon, len);
 592         length = len;
 593 out:
 594         kfree(canon);
 595         return length;
 596 }
 597
 598 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 599                                      size_t count, loff_t *ppos)
 600 {
 601         char tmpbuf[TMPBUFLEN];
 602         ssize_t length;
 603
 604         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 605         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 606 }
 607
 608 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 609                                       size_t count, loff_t *ppos)
 610 {
 611         char *page = NULL;
 612         ssize_t length;
 613         unsigned int new_value;
 614
 615         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 616         if (length)
 617                 goto out;
 618
 619         length = -ENOMEM;
 620         if (count >= PAGE_SIZE)
 621                 goto out;
 622
 623         /* No partial writes. */
 624         length = -EINVAL;
 625         if (*ppos != 0)
 626                 goto out;
 627
 628         length = -ENOMEM;
 629         page = (char *)get_zeroed_page(GFP_KERNEL);
 630         if (!page)
 631                 goto out;
 632
 633         length = -EFAULT;
 634         if (copy_from_user(page, buf, count))
 635                 goto out;
 636
 637         length = -EINVAL;
 638         if (sscanf(page, "%u", &new_value) != 1)
 639                 goto out;
 640
 641         selinux_checkreqprot = new_value ? 1 : 0;
 642         length = count;
 643 out:
 644         free_page((unsigned long) page);
 645         return length;
 646 }
 647 static const struct file_operations sel_checkreqprot_ops = {
 648         .read           = sel_read_checkreqprot,
 649         .write          = sel_write_checkreqprot,
 650         .llseek         = generic_file_llseek,
 651 };
 652
 653 /*
 654  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 655  */
 656 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 657 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 658 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 659 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 660 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 661
 662 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 663         [SEL_ACCESS] = sel_write_access,
 664         [SEL_CREATE] = sel_write_create,
 665         [SEL_RELABEL] = sel_write_relabel,
 666         [SEL_USER] = sel_write_user,
 667         [SEL_MEMBER] = sel_write_member,
 668         [SEL_CONTEXT] = sel_write_context,
 669 };
 670
 671 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 672 {
 673         ino_t ino = file->f_path.dentry->d_inode->i_ino;
 674         char *data;
 675         ssize_t rv;
 676
 677         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 678                 return -EINVAL;
 679
 680         data = simple_transaction_get(file, buf, size);
 681         if (IS_ERR(data))
 682                 return PTR_ERR(data);
 683
 684         rv = write_op[ino](file, data, size);
 685         if (rv > 0) {
 686                 simple_transaction_set(file, rv);
 687                 rv = size;
 688         }
 689         return rv;
 690 }
 691
 692 static const struct file_operations transaction_ops = {
 693         .write          = selinux_transaction_write,
 694         .read           = simple_transaction_read,
 695         .release        = simple_transaction_release,
 696         .llseek         = generic_file_llseek,
 697 };
 698
 699 /*
 700  * payload - write methods
 701  * If the method has a response, the response should be put in buf,
 702  * and the length returned.  Otherwise return 0 or and -error.
 703  */
 704
 705 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 706 {
 707         char *scon = NULL, *tcon = NULL;
 708         u32 ssid, tsid;
 709         u16 tclass;
 710         struct av_decision avd;
 711         ssize_t length;
 712
 713         length = task_has_security(current, SECURITY__COMPUTE_AV);
 714         if (length)
 715                 goto out;
 716
 717         length = -ENOMEM;
 718         scon = kzalloc(size + 1, GFP_KERNEL);
 719         if (!scon)
 720                 goto out;
 721
 722         length = -ENOMEM;
 723         tcon = kzalloc(size + 1, GFP_KERNEL);
 724         if (!tcon)
 725                 goto out;
 726
 727         length = -EINVAL;
 728         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 729                 goto out;
 730
 731         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 732         if (length)
 733                 goto out;
 734
 735         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 736         if (length)
 737                 goto out;
 738
 739         security_compute_av_user(ssid, tsid, tclass, &avd);
 740
 741         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 742                           "%x %x %x %x %u %x",
 743                           avd.allowed, 0xffffffff,
 744                           avd.auditallow, avd.auditdeny,
 745                           avd.seqno, avd.flags);
 746 out:
 747         kfree(tcon);
 748         kfree(scon);
 749         return length;
 750 }
 751
 752 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 753 {
 754         char *scon = NULL, *tcon = NULL;
 755         char *namebuf = NULL, *objname = NULL;
 756         u32 ssid, tsid, newsid;
 757         u16 tclass;
 758         ssize_t length;
 759         char *newcon = NULL;
 760         u32 len;
 761         int nargs;
 762
 763         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 764         if (length)
 765                 goto out;
 766
 767         length = -ENOMEM;
 768         scon = kzalloc(size + 1, GFP_KERNEL);
 769         if (!scon)
 770                 goto out;
 771
 772         length = -ENOMEM;
 773         tcon = kzalloc(size + 1, GFP_KERNEL);
 774         if (!tcon)
 775                 goto out;
 776
 777         length = -ENOMEM;
 778         namebuf = kzalloc(size + 1, GFP_KERNEL);
 779         if (!namebuf)
 780                 goto out;
 781
 782         length = -EINVAL;
 783         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 784         if (nargs < 3 || nargs > 4)
 785                 goto out;
 786         if (nargs == 4) {
 787                 /*
 788                  * If and when the name of new object to be queried contains
 789                  * either whitespace or multibyte characters, they shall be
 790                  * encoded based on the percentage-encoding rule.
 791                  * If not encoded, the sscanf logic picks up only left-half
 792                  * of the supplied name; splitted by a whitespace unexpectedly.
 793                  */
 794                 char   *r, *w;
 795                 int     c1, c2;
 796
 797                 r = w = namebuf;
 798                 do {
 799                         c1 = *r++;
 800                         if (c1 == '+')
 801                                 c1 = ' ';
 802                         else if (c1 == '%') {
 803                                 c1 = hex_to_bin(*r++);
 804                                 if (c1 < 0)
 805                                         goto out;
 806                                 c2 = hex_to_bin(*r++);
 807                                 if (c2 < 0)
 808                                         goto out;
 809                                 c1 = (c1 << 4) | c2;
 810                         }
 811                         *w++ = c1;
 812                 } while (c1 != '\0');
 813
 814                 objname = namebuf;
 815         }
 816
 817         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 818         if (length)
 819                 goto out;
 820
 821         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 822         if (length)
 823                 goto out;
 824
 825         length = security_transition_sid_user(ssid, tsid, tclass,
 826                                               objname, &newsid);
 827         if (length)
 828                 goto out;
 829
 830         length = security_sid_to_context(newsid, &newcon, &len);
 831         if (length)
 832                 goto out;
 833
 834         length = -ERANGE;
 835         if (len > SIMPLE_TRANSACTION_LIMIT) {
 836                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 837                         "payload max\n", __func__, len);
 838                 goto out;
 839         }
 840
 841         memcpy(buf, newcon, len);
 842         length = len;
 843 out:
 844         kfree(newcon);
 845         kfree(namebuf);
 846         kfree(tcon);
 847         kfree(scon);
 848         return length;
 849 }
 850
 851 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 852 {
 853         char *scon = NULL, *tcon = NULL;
 854         u32 ssid, tsid, newsid;
 855         u16 tclass;
 856         ssize_t length;
 857         char *newcon = NULL;
 858         u32 len;
 859
 860         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 861         if (length)
 862                 goto out;
 863
 864         length = -ENOMEM;
 865         scon = kzalloc(size + 1, GFP_KERNEL);
 866         if (!scon)
 867                 goto out;
 868
 869         length = -ENOMEM;
 870         tcon = kzalloc(size + 1, GFP_KERNEL);
 871         if (!tcon)
 872                 goto out;
 873
 874         length = -EINVAL;
 875         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 876                 goto out;
 877
 878         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 879         if (length)
 880                 goto out;
 881
 882         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 883         if (length)
 884                 goto out;
 885
 886         length = security_change_sid(ssid, tsid, tclass, &newsid);
 887         if (length)
 888                 goto out;
 889
 890         length = security_sid_to_context(newsid, &newcon, &len);
 891         if (length)
 892                 goto out;
 893
 894         length = -ERANGE;
 895         if (len > SIMPLE_TRANSACTION_LIMIT)
 896                 goto out;
 897
 898         memcpy(buf, newcon, len);
 899         length = len;
 900 out:
 901         kfree(newcon);
 902         kfree(tcon);
 903         kfree(scon);
 904         return length;
 905 }
 906
 907 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 908 {
 909         char *con = NULL, *user = NULL, *ptr;
 910         u32 sid, *sids = NULL;
 911         ssize_t length;
 912         char *newcon;
 913         int i, rc;
 914         u32 len, nsids;
 915
 916         length = task_has_security(current, SECURITY__COMPUTE_USER);
 917         if (length)
 918                 goto out;
 919
 920         length = -ENOMEM;
 921         con = kzalloc(size + 1, GFP_KERNEL);
 922         if (!con)
 923                 goto out;
 924
 925         length = -ENOMEM;
 926         user = kzalloc(size + 1, GFP_KERNEL);
 927         if (!user)
 928                 goto out;
 929
 930         length = -EINVAL;
 931         if (sscanf(buf, "%s %s", con, user) != 2)
 932                 goto out;
 933
 934         length = security_context_to_sid(con, strlen(con) + 1, &sid);
 935         if (length)
 936                 goto out;
 937
 938         length = security_get_user_sids(sid, user, &sids, &nsids);
 939         if (length)
 940                 goto out;
 941
 942         length = sprintf(buf, "%u", nsids) + 1;
 943         ptr = buf + length;
 944         for (i = 0; i < nsids; i++) {
 945                 rc = security_sid_to_context(sids[i], &newcon, &len);
 946                 if (rc) {
 947                         length = rc;
 948                         goto out;
 949                 }
 950                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 951                         kfree(newcon);
 952                         length = -ERANGE;
 953                         goto out;
 954                 }
 955                 memcpy(ptr, newcon, len);
 956                 kfree(newcon);
 957                 ptr += len;
 958                 length += len;
 959         }
 960 out:
 961         kfree(sids);
 962         kfree(user);
 963         kfree(con);
 964         return length;
 965 }
 966
 967 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 968 {
 969         char *scon = NULL, *tcon = NULL;
 970         u32 ssid, tsid, newsid;
 971         u16 tclass;
 972         ssize_t length;
 973         char *newcon = NULL;
 974         u32 len;
 975
 976         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 977         if (length)
 978                 goto out;
 979
 980         length = -ENOMEM;
 981         scon = kzalloc(size + 1, GFP_KERNEL);
 982         if (!scon)
 983                 goto out;
 984
 985         length = -ENOMEM;
 986         tcon = kzalloc(size + 1, GFP_KERNEL);
 987         if (!tcon)
 988                 goto out;
 989
 990         length = -EINVAL;
 991         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 992                 goto out;
 993
 994         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 995         if (length)
 996                 goto out;
 997
 998         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 999         if (length)
1000                 goto out;
1001
1002         length = security_member_sid(ssid, tsid, tclass, &newsid);
1003         if (length)
1004                 goto out;
1005
1006         length = security_sid_to_context(newsid, &newcon, &len);
1007         if (length)
1008                 goto out;
1009
1010         length = -ERANGE;
1011         if (len > SIMPLE_TRANSACTION_LIMIT) {
1012                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1013                         "payload max\n", __func__, len);
1014                 goto out;
1015         }
1016
1017         memcpy(buf, newcon, len);
1018         length = len;
1019 out:
1020         kfree(newcon);
1021         kfree(tcon);
1022         kfree(scon);
1023         return length;
1024 }
1025
1026 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1027 {
1028         struct inode *ret = new_inode(sb);
1029
1030         if (ret) {
1031                 ret->i_mode = mode;
1032                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1033         }
1034         return ret;
1035 }
1036
1037 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1038                              size_t count, loff_t *ppos)
1039 {
1040         char *page = NULL;
1041         ssize_t length;
1042         ssize_t ret;
1043         int cur_enforcing;
1044         struct inode *inode = filep->f_path.dentry->d_inode;
1045         unsigned index = inode->i_ino & SEL_INO_MASK;
1046         const char *name = filep->f_path.dentry->d_name.name;
1047
1048         mutex_lock(&sel_mutex);
1049
1050         ret = -EINVAL;
1051         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1052                 goto out;
1053
1054         ret = -ENOMEM;
1055         page = (char *)get_zeroed_page(GFP_KERNEL);
1056         if (!page)
1057                 goto out;
1058
1059         cur_enforcing = security_get_bool_value(index);
1060         if (cur_enforcing < 0) {
1061                 ret = cur_enforcing;
1062                 goto out;
1063         }
1064         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1065                           bool_pending_values[index]);
1066         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1067 out:
1068         mutex_unlock(&sel_mutex);
1069         free_page((unsigned long)page);
1070         return ret;
1071 }
1072
1073 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1074                               size_t count, loff_t *ppos)
1075 {
1076         char *page = NULL;
1077         ssize_t length;
1078         int new_value;
1079         struct inode *inode = filep->f_path.dentry->d_inode;
1080         unsigned index = inode->i_ino & SEL_INO_MASK;
1081         const char *name = filep->f_path.dentry->d_name.name;
1082
1083         mutex_lock(&sel_mutex);
1084
1085         length = task_has_security(current, SECURITY__SETBOOL);
1086         if (length)
1087                 goto out;
1088
1089         length = -EINVAL;
1090         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1091                 goto out;
1092
1093         length = -ENOMEM;
1094         if (count >= PAGE_SIZE)
1095                 goto out;
1096
1097         /* No partial writes. */
1098         length = -EINVAL;
1099         if (*ppos != 0)
1100                 goto out;
1101
1102         length = -ENOMEM;
1103         page = (char *)get_zeroed_page(GFP_KERNEL);
1104         if (!page)
1105                 goto out;
1106
1107         length = -EFAULT;
1108         if (copy_from_user(page, buf, count))
1109                 goto out;
1110
1111         length = -EINVAL;
1112         if (sscanf(page, "%d", &new_value) != 1)
1113                 goto out;
1114
1115         if (new_value)
1116                 new_value = 1;
1117
1118         bool_pending_values[index] = new_value;
1119         length = count;
1120
1121 out:
1122         mutex_unlock(&sel_mutex);
1123         free_page((unsigned long) page);
1124         return length;
1125 }
1126
1127 static const struct file_operations sel_bool_ops = {
1128         .read           = sel_read_bool,
1129         .write          = sel_write_bool,
1130         .llseek         = generic_file_llseek,
1131 };
1132
1133 static ssize_t sel_commit_bools_write(struct file *filep,
1134                                       const char __user *buf,
1135                                       size_t count, loff_t *ppos)
1136 {
1137         char *page = NULL;
1138         ssize_t length;
1139         int new_value;
1140
1141         mutex_lock(&sel_mutex);
1142
1143         length = task_has_security(current, SECURITY__SETBOOL);
1144         if (length)
1145                 goto out;
1146
1147         length = -ENOMEM;
1148         if (count >= PAGE_SIZE)
1149                 goto out;
1150
1151         /* No partial writes. */
1152         length = -EINVAL;
1153         if (*ppos != 0)
1154                 goto out;
1155
1156         length = -ENOMEM;
1157         page = (char *)get_zeroed_page(GFP_KERNEL);
1158         if (!page)
1159                 goto out;
1160
1161         length = -EFAULT;
1162         if (copy_from_user(page, buf, count))
1163                 goto out;
1164
1165         length = -EINVAL;
1166         if (sscanf(page, "%d", &new_value) != 1)
1167                 goto out;
1168
1169         length = 0;
1170         if (new_value && bool_pending_values)
1171                 length = security_set_bools(bool_num, bool_pending_values);
1172
1173         if (!length)
1174                 length = count;
1175
1176 out:
1177         mutex_unlock(&sel_mutex);
1178         free_page((unsigned long) page);
1179         return length;
1180 }
1181
1182 static const struct file_operations sel_commit_bools_ops = {
1183         .write          = sel_commit_bools_write,
1184         .llseek         = generic_file_llseek,
1185 };
1186
1187 static void sel_remove_entries(struct dentry *de)
1188 {
1189         struct list_head *node;
1190
1191         spin_lock(&de->d_lock);
1192         node = de->d_subdirs.next;
1193         while (node != &de->d_subdirs) {
1194                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1195
1196                 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1197                 list_del_init(node);
1198
1199                 if (d->d_inode) {
1200                         dget_dlock(d);
1201                         spin_unlock(&de->d_lock);
1202                         spin_unlock(&d->d_lock);
1203                         d_delete(d);
1204                         simple_unlink(de->d_inode, d);
1205                         dput(d);
1206                         spin_lock(&de->d_lock);
1207                 } else
1208                         spin_unlock(&d->d_lock);
1209                 node = de->d_subdirs.next;
1210         }
1211
1212         spin_unlock(&de->d_lock);
1213 }
1214
1215 #define BOOL_DIR_NAME "booleans"
1216
1217 static int sel_make_bools(void)
1218 {
1219         int i, ret;
1220         ssize_t len;
1221         struct dentry *dentry = NULL;
1222         struct dentry *dir = bool_dir;
1223         struct inode *inode = NULL;
1224         struct inode_security_struct *isec;
1225         char **names = NULL, *page;
1226         int num;
1227         int *values = NULL;
1228         u32 sid;
1229
1230         /* remove any existing files */
1231         for (i = 0; i < bool_num; i++)
1232                 kfree(bool_pending_names[i]);
1233         kfree(bool_pending_names);
1234         kfree(bool_pending_values);
1235         bool_pending_names = NULL;
1236         bool_pending_values = NULL;
1237
1238         sel_remove_entries(dir);
1239
1240         ret = -ENOMEM;
1241         page = (char *)get_zeroed_page(GFP_KERNEL);
1242         if (!page)
1243                 goto out;
1244
1245         ret = security_get_bools(&num, &names, &values);
1246         if (ret)
1247                 goto out;
1248
1249         for (i = 0; i < num; i++) {
1250                 ret = -ENOMEM;
1251                 dentry = d_alloc_name(dir, names[i]);
1252                 if (!dentry)
1253                         goto out;
1254
1255                 ret = -ENOMEM;
1256                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1257                 if (!inode)
1258                         goto out;
1259
1260                 ret = -EINVAL;
1261                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1262                 if (len < 0)
1263                         goto out;
1264
1265                 ret = -ENAMETOOLONG;
1266                 if (len >= PAGE_SIZE)
1267                         goto out;
1268
1269                 isec = (struct inode_security_struct *)inode->i_security;
1270                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1271                 if (ret)
1272                         goto out;
1273
1274                 isec->sid = sid;
1275                 isec->initialized = 1;
1276                 inode->i_fop = &sel_bool_ops;
1277                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1278                 d_add(dentry, inode);
1279         }
1280         bool_num = num;
1281         bool_pending_names = names;
1282         bool_pending_values = values;
1283
1284         free_page((unsigned long)page);
1285         return 0;
1286 out:
1287         free_page((unsigned long)page);
1288
1289         if (names) {
1290                 for (i = 0; i < num; i++)
1291                         kfree(names[i]);
1292                 kfree(names);
1293         }
1294         kfree(values);
1295         sel_remove_entries(dir);
1296
1297         return ret;
1298 }
1299
1300 #define NULL_FILE_NAME "null"
1301
1302 struct dentry *selinux_null;
1303
1304 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1305                                             size_t count, loff_t *ppos)
1306 {
1307         char tmpbuf[TMPBUFLEN];
1308         ssize_t length;
1309
1310         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1311         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1312 }
1313
1314 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1315                                              const char __user *buf,
1316                                              size_t count, loff_t *ppos)
1317
1318 {
1319         char *page = NULL;
1320         ssize_t ret;
1321         int new_value;
1322
1323         ret = task_has_security(current, SECURITY__SETSECPARAM);
1324         if (ret)
1325                 goto out;
1326
1327         ret = -ENOMEM;
1328         if (count >= PAGE_SIZE)
1329                 goto out;
1330
1331         /* No partial writes. */
1332         ret = -EINVAL;
1333         if (*ppos != 0)
1334                 goto out;
1335
1336         ret = -ENOMEM;
1337         page = (char *)get_zeroed_page(GFP_KERNEL);
1338         if (!page)
1339                 goto out;
1340
1341         ret = -EFAULT;
1342         if (copy_from_user(page, buf, count))
1343                 goto out;
1344
1345         ret = -EINVAL;
1346         if (sscanf(page, "%u", &new_value) != 1)
1347                 goto out;
1348
1349         avc_cache_threshold = new_value;
1350
1351         ret = count;
1352 out:
1353         free_page((unsigned long)page);
1354         return ret;
1355 }
1356
1357 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1358                                        size_t count, loff_t *ppos)
1359 {
1360         char *page;
1361         ssize_t length;
1362
1363         page = (char *)__get_free_page(GFP_KERNEL);
1364         if (!page)
1365                 return -ENOMEM;
1366
1367         length = avc_get_hash_stats(page);
1368         if (length >= 0)
1369                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1370         free_page((unsigned long)page);
1371
1372         return length;
1373 }
1374
1375 static const struct file_operations sel_avc_cache_threshold_ops = {
1376         .read           = sel_read_avc_cache_threshold,
1377         .write          = sel_write_avc_cache_threshold,
1378         .llseek         = generic_file_llseek,
1379 };
1380
1381 static const struct file_operations sel_avc_hash_stats_ops = {
1382         .read           = sel_read_avc_hash_stats,
1383         .llseek         = generic_file_llseek,
1384 };
1385
1386 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1387 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1388 {
1389         int cpu;
1390
1391         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1392                 if (!cpu_possible(cpu))
1393                         continue;
1394                 *idx = cpu + 1;
1395                 return &per_cpu(avc_cache_stats, cpu);
1396         }
1397         return NULL;
1398 }
1399
1400 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1401 {
1402         loff_t n = *pos - 1;
1403
1404         if (*pos == 0)
1405                 return SEQ_START_TOKEN;
1406
1407         return sel_avc_get_stat_idx(&n);
1408 }
1409
1410 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1411 {
1412         return sel_avc_get_stat_idx(pos);
1413 }
1414
1415 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1416 {
1417         struct avc_cache_stats *st = v;
1418
1419         if (v == SEQ_START_TOKEN)
1420                 seq_printf(seq, "lookups hits misses allocations reclaims "
1421                            "frees\n");
1422         else {
1423                 unsigned int lookups = st->lookups;
1424                 unsigned int misses = st->misses;
1425                 unsigned int hits = lookups - misses;
1426                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1427                            hits, misses, st->allocations,
1428                            st->reclaims, st->frees);
1429         }
1430         return 0;
1431 }
1432
1433 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1434 { }
1435
1436 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1437         .start          = sel_avc_stats_seq_start,
1438         .next           = sel_avc_stats_seq_next,
1439         .show           = sel_avc_stats_seq_show,
1440         .stop           = sel_avc_stats_seq_stop,
1441 };
1442
1443 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1444 {
1445         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1446 }
1447
1448 static const struct file_operations sel_avc_cache_stats_ops = {
1449         .open           = sel_open_avc_cache_stats,
1450         .read           = seq_read,
1451         .llseek         = seq_lseek,
1452         .release        = seq_release,
1453 };
1454 #endif
1455
1456 static int sel_make_avc_files(struct dentry *dir)
1457 {
1458         int i;
1459         static struct tree_descr files[] = {
1460                 { "cache_threshold",
1461                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1462                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1463 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1464                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1465 #endif
1466         };
1467
1468         for (i = 0; i < ARRAY_SIZE(files); i++) {
1469                 struct inode *inode;
1470                 struct dentry *dentry;
1471
1472                 dentry = d_alloc_name(dir, files[i].name);
1473                 if (!dentry)
1474                         return -ENOMEM;
1475
1476                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1477                 if (!inode)
1478                         return -ENOMEM;
1479
1480                 inode->i_fop = files[i].ops;
1481                 inode->i_ino = ++sel_last_ino;
1482                 d_add(dentry, inode);
1483         }
1484
1485         return 0;
1486 }
1487
1488 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1489                                 size_t count, loff_t *ppos)
1490 {
1491         struct inode *inode;
1492         char *con;
1493         u32 sid, len;
1494         ssize_t ret;
1495
1496         inode = file->f_path.dentry->d_inode;
1497         sid = inode->i_ino&SEL_INO_MASK;
1498         ret = security_sid_to_context(sid, &con, &len);
1499         if (ret)
1500                 return ret;
1501
1502         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1503         kfree(con);
1504         return ret;
1505 }
1506
1507 static const struct file_operations sel_initcon_ops = {
1508         .read           = sel_read_initcon,
1509         .llseek         = generic_file_llseek,
1510 };
1511
1512 static int sel_make_initcon_files(struct dentry *dir)
1513 {
1514         int i;
1515
1516         for (i = 1; i <= SECINITSID_NUM; i++) {
1517                 struct inode *inode;
1518                 struct dentry *dentry;
1519                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1520                 if (!dentry)
1521                         return -ENOMEM;
1522
1523                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1524                 if (!inode)
1525                         return -ENOMEM;
1526
1527                 inode->i_fop = &sel_initcon_ops;
1528                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1529                 d_add(dentry, inode);
1530         }
1531
1532         return 0;
1533 }
1534
1535 static inline unsigned int sel_div(unsigned long a, unsigned long b)
1536 {
1537         return a / b - (a % b < 0);
1538 }
1539
1540 static inline unsigned long sel_class_to_ino(u16 class)
1541 {
1542         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1543 }
1544
1545 static inline u16 sel_ino_to_class(unsigned long ino)
1546 {
1547         return sel_div(ino & SEL_INO_MASK, SEL_VEC_MAX + 1);
1548 }
1549
1550 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1551 {
1552         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1553 }
1554
1555 static inline u32 sel_ino_to_perm(unsigned long ino)
1556 {
1557         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1558 }
1559
1560 static ssize_t sel_read_class(struct file *file, char __user *buf,
1561                                 size_t count, loff_t *ppos)
1562 {
1563         ssize_t rc, len;
1564         char *page;
1565         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1566
1567         page = (char *)__get_free_page(GFP_KERNEL);
1568         if (!page)
1569                 return -ENOMEM;
1570
1571         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
1572         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1573         free_page((unsigned long)page);
1574
1575         return rc;
1576 }
1577
1578 static const struct file_operations sel_class_ops = {
1579         .read           = sel_read_class,
1580         .llseek         = generic_file_llseek,
1581 };
1582
1583 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1584                                 size_t count, loff_t *ppos)
1585 {
1586         ssize_t rc, len;
1587         char *page;
1588         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1589
1590         page = (char *)__get_free_page(GFP_KERNEL);
1591         if (!page)
1592                 return -ENOMEM;
1593
1594         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
1595         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1596         free_page((unsigned long)page);
1597
1598         return rc;
1599 }
1600
1601 static const struct file_operations sel_perm_ops = {
1602         .read           = sel_read_perm,
1603         .llseek         = generic_file_llseek,
1604 };
1605
1606 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1607                                   size_t count, loff_t *ppos)
1608 {
1609         int value;
1610         char tmpbuf[TMPBUFLEN];
1611         ssize_t length;
1612         unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1613
1614         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1615         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1616
1617         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1618 }
1619
1620 static const struct file_operations sel_policycap_ops = {
1621         .read           = sel_read_policycap,
1622         .llseek         = generic_file_llseek,
1623 };
1624
1625 static int sel_make_perm_files(char *objclass, int classvalue,
1626                                 struct dentry *dir)
1627 {
1628         int i, rc, nperms;
1629         char **perms;
1630
1631         rc = security_get_permissions(objclass, &perms, &nperms);
1632         if (rc)
1633                 return rc;
1634
1635         for (i = 0; i < nperms; i++) {
1636                 struct inode *inode;
1637                 struct dentry *dentry;
1638
1639                 rc = -ENOMEM;
1640                 dentry = d_alloc_name(dir, perms[i]);
1641                 if (!dentry)
1642                         goto out;
1643
1644                 rc = -ENOMEM;
1645                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1646                 if (!inode)
1647                         goto out;
1648
1649                 inode->i_fop = &sel_perm_ops;
1650                 /* i+1 since perm values are 1-indexed */
1651                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1652                 d_add(dentry, inode);
1653         }
1654         rc = 0;
1655 out:
1656         for (i = 0; i < nperms; i++)
1657                 kfree(perms[i]);
1658         kfree(perms);
1659         return rc;
1660 }
1661
1662 static int sel_make_class_dir_entries(char *classname, int index,
1663                                         struct dentry *dir)
1664 {
1665         struct dentry *dentry = NULL;
1666         struct inode *inode = NULL;
1667         int rc;
1668
1669         dentry = d_alloc_name(dir, "index");
1670         if (!dentry)
1671                 return -ENOMEM;
1672
1673         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1674         if (!inode)
1675                 return -ENOMEM;
1676
1677         inode->i_fop = &sel_class_ops;
1678         inode->i_ino = sel_class_to_ino(index);
1679         d_add(dentry, inode);
1680
1681         dentry = d_alloc_name(dir, "perms");
1682         if (!dentry)
1683                 return -ENOMEM;
1684
1685         rc = sel_make_dir(dir->d_inode, dentry, &last_class_ino);
1686         if (rc)
1687                 return rc;
1688
1689         rc = sel_make_perm_files(classname, index, dentry);
1690
1691         return rc;
1692 }
1693
1694 static void sel_remove_classes(void)
1695 {
1696         struct list_head *class_node;
1697
1698         list_for_each(class_node, &class_dir->d_subdirs) {
1699                 struct dentry *class_subdir = list_entry(class_node,
1700                                         struct dentry, d_u.d_child);
1701                 struct list_head *class_subdir_node;
1702
1703                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1704                         struct dentry *d = list_entry(class_subdir_node,
1705                                                 struct dentry, d_u.d_child);
1706
1707                         if (d->d_inode)
1708                                 if (d->d_inode->i_mode & S_IFDIR)
1709                                         sel_remove_entries(d);
1710                 }
1711
1712                 sel_remove_entries(class_subdir);
1713         }
1714
1715         sel_remove_entries(class_dir);
1716 }
1717
1718 static int sel_make_classes(void)
1719 {
1720         int rc, nclasses, i;
1721         char **classes;
1722
1723         /* delete any existing entries */
1724         sel_remove_classes();
1725
1726         rc = security_get_classes(&classes, &nclasses);
1727         if (rc)
1728                 return rc;
1729
1730         /* +2 since classes are 1-indexed */
1731         last_class_ino = sel_class_to_ino(nclasses + 2);
1732
1733         for (i = 0; i < nclasses; i++) {
1734                 struct dentry *class_name_dir;
1735
1736                 rc = -ENOMEM;
1737                 class_name_dir = d_alloc_name(class_dir, classes[i]);
1738                 if (!class_name_dir)
1739                         goto out;
1740
1741                 rc = sel_make_dir(class_dir->d_inode, class_name_dir,
1742                                 &last_class_ino);
1743                 if (rc)
1744                         goto out;
1745
1746                 /* i+1 since class values are 1-indexed */
1747                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1748                                 class_name_dir);
1749                 if (rc)
1750                         goto out;
1751         }
1752         rc = 0;
1753 out:
1754         for (i = 0; i < nclasses; i++)
1755                 kfree(classes[i]);
1756         kfree(classes);
1757         return rc;
1758 }
1759
1760 static int sel_make_policycap(void)
1761 {
1762         unsigned int iter;
1763         struct dentry *dentry = NULL;
1764         struct inode *inode = NULL;
1765
1766         sel_remove_entries(policycap_dir);
1767
1768         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1769                 if (iter < ARRAY_SIZE(policycap_names))
1770                         dentry = d_alloc_name(policycap_dir,
1771                                               policycap_names[iter]);
1772                 else
1773                         dentry = d_alloc_name(policycap_dir, "unknown");
1774
1775                 if (dentry == NULL)
1776                         return -ENOMEM;
1777
1778                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1779                 if (inode == NULL)
1780                         return -ENOMEM;
1781
1782                 inode->i_fop = &sel_policycap_ops;
1783                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1784                 d_add(dentry, inode);
1785         }
1786
1787         return 0;
1788 }
1789
1790 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
1791                         unsigned long *ino)
1792 {
1793         struct inode *inode;
1794
1795         inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1796         if (!inode)
1797                 return -ENOMEM;
1798
1799         inode->i_op = &simple_dir_inode_operations;
1800         inode->i_fop = &simple_dir_operations;
1801         inode->i_ino = ++(*ino);
1802         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1803         inc_nlink(inode);
1804         d_add(dentry, inode);
1805         /* bump link count on parent directory, too */
1806         inc_nlink(dir);
1807
1808         return 0;
1809 }
1810
1811 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1812 {
1813         int ret;
1814         struct dentry *dentry;
1815         struct inode *inode, *root_inode;
1816         struct inode_security_struct *isec;
1817
1818         static struct tree_descr selinux_files[] = {
1819                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1820                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1821                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1822                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1823                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1824                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1825                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1826                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1827                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1828                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1829                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1830                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1831                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1832                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1833                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1834                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1835                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUSR},
1836                 /* last one */ {""}
1837         };
1838         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1839         if (ret)
1840                 goto err;
1841
1842         root_inode = sb->s_root->d_inode;
1843
1844         ret = -ENOMEM;
1845         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1846         if (!dentry)
1847                 goto err;
1848
1849         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1850         if (ret)
1851                 goto err;
1852
1853         bool_dir = dentry;
1854
1855         ret = -ENOMEM;
1856         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1857         if (!dentry)
1858                 goto err;
1859
1860         ret = -ENOMEM;
1861         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1862         if (!inode)
1863                 goto err;
1864
1865         inode->i_ino = ++sel_last_ino;
1866         isec = (struct inode_security_struct *)inode->i_security;
1867         isec->sid = SECINITSID_DEVNULL;
1868         isec->sclass = SECCLASS_CHR_FILE;
1869         isec->initialized = 1;
1870
1871         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1872         d_add(dentry, inode);
1873         selinux_null = dentry;
1874
1875         ret = -ENOMEM;
1876         dentry = d_alloc_name(sb->s_root, "avc");
1877         if (!dentry)
1878                 goto err;
1879
1880         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1881         if (ret)
1882                 goto err;
1883
1884         ret = sel_make_avc_files(dentry);
1885         if (ret)
1886                 goto err;
1887
1888         ret = -ENOMEM;
1889         dentry = d_alloc_name(sb->s_root, "initial_contexts");
1890         if (!dentry)
1891                 goto err;
1892
1893         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1894         if (ret)
1895                 goto err;
1896
1897         ret = sel_make_initcon_files(dentry);
1898         if (ret)
1899                 goto err;
1900
1901         ret = -ENOMEM;
1902         dentry = d_alloc_name(sb->s_root, "class");
1903         if (!dentry)
1904                 goto err;
1905
1906         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1907         if (ret)
1908                 goto err;
1909
1910         class_dir = dentry;
1911
1912         ret = -ENOMEM;
1913         dentry = d_alloc_name(sb->s_root, "policy_capabilities");
1914         if (!dentry)
1915                 goto err;
1916
1917         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1918         if (ret)
1919                 goto err;
1920
1921         policycap_dir = dentry;
1922
1923         return 0;
1924 err:
1925         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1926                 __func__);
1927         return ret;
1928 }
1929
1930 static struct dentry *sel_mount(struct file_system_type *fs_type,
1931                       int flags, const char *dev_name, void *data)
1932 {
1933         return mount_single(fs_type, flags, data, sel_fill_super);
1934 }
1935
1936 static struct file_system_type sel_fs_type = {
1937         .name           = "selinuxfs",
1938         .mount          = sel_mount,
1939         .kill_sb        = kill_litter_super,
1940 };
1941
1942 struct vfsmount *selinuxfs_mount;
1943 static struct kobject *selinuxfs_kobj;
1944
1945 static int __init init_sel_fs(void)
1946 {
1947         int err;
1948
1949         if (!selinux_enabled)
1950                 return 0;
1951
1952         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1953         if (!selinuxfs_kobj)
1954                 return -ENOMEM;
1955
1956         err = register_filesystem(&sel_fs_type);
1957         if (err) {
1958                 kobject_put(selinuxfs_kobj);
1959                 return err;
1960         }
1961
1962         selinuxfs_mount = kern_mount(&sel_fs_type);
1963         if (IS_ERR(selinuxfs_mount)) {
1964                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1965                 err = PTR_ERR(selinuxfs_mount);
1966                 selinuxfs_mount = NULL;
1967         }
1968
1969         return err;
1970 }
1971
1972 __initcall(init_sel_fs);
1973
1974 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1975 void exit_sel_fs(void)
1976 {
1977         kobject_put(selinuxfs_kobj);
1978         kern_unmount(selinuxfs_mount);
1979         unregister_filesystem(&sel_fs_type);
1980 }
1981 #endif