security/selinux/selinuxfs.c

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