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                         from_kuid(&init_user_ns, 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 = file_inode(filp)->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                         from_kuid(&init_user_ns, 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 struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 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_DONTEXPAND | VM_DONTDUMP;
 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         .llseek         = generic_file_llseek,
 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                 from_kuid(&init_user_ns, 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_inode(file)->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         char *namebuf = NULL, *objname = NULL;
 757         u32 ssid, tsid, newsid;
 758         u16 tclass;
 759         ssize_t length;
 760         char *newcon = NULL;
 761         u32 len;
 762         int nargs;
 763
 764         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 765         if (length)
 766                 goto out;
 767
 768         length = -ENOMEM;
 769         scon = kzalloc(size + 1, GFP_KERNEL);
 770         if (!scon)
 771                 goto out;
 772
 773         length = -ENOMEM;
 774         tcon = kzalloc(size + 1, GFP_KERNEL);
 775         if (!tcon)
 776                 goto out;
 777
 778         length = -ENOMEM;
 779         namebuf = kzalloc(size + 1, GFP_KERNEL);
 780         if (!namebuf)
 781                 goto out;
 782
 783         length = -EINVAL;
 784         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 785         if (nargs < 3 || nargs > 4)
 786                 goto out;
 787         if (nargs == 4) {
 788                 /*
 789                  * If and when the name of new object to be queried contains
 790                  * either whitespace or multibyte characters, they shall be
 791                  * encoded based on the percentage-encoding rule.
 792                  * If not encoded, the sscanf logic picks up only left-half
 793                  * of the supplied name; splitted by a whitespace unexpectedly.
 794                  */
 795                 char   *r, *w;
 796                 int     c1, c2;
 797
 798                 r = w = namebuf;
 799                 do {
 800                         c1 = *r++;
 801                         if (c1 == '+')
 802                                 c1 = ' ';
 803                         else if (c1 == '%') {
 804                                 c1 = hex_to_bin(*r++);
 805                                 if (c1 < 0)
 806                                         goto out;
 807                                 c2 = hex_to_bin(*r++);
 808                                 if (c2 < 0)
 809                                         goto out;
 810                                 c1 = (c1 << 4) | c2;
 811                         }
 812                         *w++ = c1;
 813                 } while (c1 != '\0');
 814
 815                 objname = namebuf;
 816         }
 817
 818         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 819         if (length)
 820                 goto out;
 821
 822         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 823         if (length)
 824                 goto out;
 825
 826         length = security_transition_sid_user(ssid, tsid, tclass,
 827                                               objname, &newsid);
 828         if (length)
 829                 goto out;
 830
 831         length = security_sid_to_context(newsid, &newcon, &len);
 832         if (length)
 833                 goto out;
 834
 835         length = -ERANGE;
 836         if (len > SIMPLE_TRANSACTION_LIMIT) {
 837                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 838                         "payload max\n", __func__, len);
 839                 goto out;
 840         }
 841
 842         memcpy(buf, newcon, len);
 843         length = len;
 844 out:
 845         kfree(newcon);
 846         kfree(namebuf);
 847         kfree(tcon);
 848         kfree(scon);
 849         return length;
 850 }
 851
 852 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 853 {
 854         char *scon = NULL, *tcon = NULL;
 855         u32 ssid, tsid, newsid;
 856         u16 tclass;
 857         ssize_t length;
 858         char *newcon = NULL;
 859         u32 len;
 860
 861         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 862         if (length)
 863                 goto out;
 864
 865         length = -ENOMEM;
 866         scon = kzalloc(size + 1, GFP_KERNEL);
 867         if (!scon)
 868                 goto out;
 869
 870         length = -ENOMEM;
 871         tcon = kzalloc(size + 1, GFP_KERNEL);
 872         if (!tcon)
 873                 goto out;
 874
 875         length = -EINVAL;
 876         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 877                 goto out;
 878
 879         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 880         if (length)
 881                 goto out;
 882
 883         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 884         if (length)
 885                 goto out;
 886
 887         length = security_change_sid(ssid, tsid, tclass, &newsid);
 888         if (length)
 889                 goto out;
 890
 891         length = security_sid_to_context(newsid, &newcon, &len);
 892         if (length)
 893                 goto out;
 894
 895         length = -ERANGE;
 896         if (len > SIMPLE_TRANSACTION_LIMIT)
 897                 goto out;
 898
 899         memcpy(buf, newcon, len);
 900         length = len;
 901 out:
 902         kfree(newcon);
 903         kfree(tcon);
 904         kfree(scon);
 905         return length;
 906 }
 907
 908 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 909 {
 910         char *con = NULL, *user = NULL, *ptr;
 911         u32 sid, *sids = NULL;
 912         ssize_t length;
 913         char *newcon;
 914         int i, rc;
 915         u32 len, nsids;
 916
 917         length = task_has_security(current, SECURITY__COMPUTE_USER);
 918         if (length)
 919                 goto out;
 920
 921         length = -ENOMEM;
 922         con = kzalloc(size + 1, GFP_KERNEL);
 923         if (!con)
 924                 goto out;
 925
 926         length = -ENOMEM;
 927         user = kzalloc(size + 1, GFP_KERNEL);
 928         if (!user)
 929                 goto out;
 930
 931         length = -EINVAL;
 932         if (sscanf(buf, "%s %s", con, user) != 2)
 933                 goto out;
 934
 935         length = security_context_to_sid(con, strlen(con) + 1, &sid);
 936         if (length)
 937                 goto out;
 938
 939         length = security_get_user_sids(sid, user, &sids, &nsids);
 940         if (length)
 941                 goto out;
 942
 943         length = sprintf(buf, "%u", nsids) + 1;
 944         ptr = buf + length;
 945         for (i = 0; i < nsids; i++) {
 946                 rc = security_sid_to_context(sids[i], &newcon, &len);
 947                 if (rc) {
 948                         length = rc;
 949                         goto out;
 950                 }
 951                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 952                         kfree(newcon);
 953                         length = -ERANGE;
 954                         goto out;
 955                 }
 956                 memcpy(ptr, newcon, len);
 957                 kfree(newcon);
 958                 ptr += len;
 959                 length += len;
 960         }
 961 out:
 962         kfree(sids);
 963         kfree(user);
 964         kfree(con);
 965         return length;
 966 }
 967
 968 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 969 {
 970         char *scon = NULL, *tcon = NULL;
 971         u32 ssid, tsid, newsid;
 972         u16 tclass;
 973         ssize_t length;
 974         char *newcon = NULL;
 975         u32 len;
 976
 977         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 978         if (length)
 979                 goto out;
 980
 981         length = -ENOMEM;
 982         scon = kzalloc(size + 1, GFP_KERNEL);
 983         if (!scon)
 984                 goto out;
 985
 986         length = -ENOMEM;
 987         tcon = kzalloc(size + 1, GFP_KERNEL);
 988         if (!tcon)
 989                 goto out;
 990
 991         length = -EINVAL;
 992         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 993                 goto out;
 994
 995         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 996         if (length)
 997                 goto out;
 998
 999         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1000         if (length)
1001                 goto out;
1002
1003         length = security_member_sid(ssid, tsid, tclass, &newsid);
1004         if (length)
1005                 goto out;
1006
1007         length = security_sid_to_context(newsid, &newcon, &len);
1008         if (length)
1009                 goto out;
1010
1011         length = -ERANGE;
1012         if (len > SIMPLE_TRANSACTION_LIMIT) {
1013                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1014                         "payload max\n", __func__, len);
1015                 goto out;
1016         }
1017
1018         memcpy(buf, newcon, len);
1019         length = len;
1020 out:
1021         kfree(newcon);
1022         kfree(tcon);
1023         kfree(scon);
1024         return length;
1025 }
1026
1027 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1028 {
1029         struct inode *ret = new_inode(sb);
1030
1031         if (ret) {
1032                 ret->i_mode = mode;
1033                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1034         }
1035         return ret;
1036 }
1037
1038 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1039                              size_t count, loff_t *ppos)
1040 {
1041         char *page = NULL;
1042         ssize_t length;
1043         ssize_t ret;
1044         int cur_enforcing;
1045         unsigned index = file_inode(filep)->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         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1080         const char *name = filep->f_path.dentry->d_name.name;
1081
1082         mutex_lock(&sel_mutex);
1083
1084         length = task_has_security(current, SECURITY__SETBOOL);
1085         if (length)
1086                 goto out;
1087
1088         length = -EINVAL;
1089         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1090                 goto out;
1091
1092         length = -ENOMEM;
1093         if (count >= PAGE_SIZE)
1094                 goto out;
1095
1096         /* No partial writes. */
1097         length = -EINVAL;
1098         if (*ppos != 0)
1099                 goto out;
1100
1101         length = -ENOMEM;
1102         page = (char *)get_zeroed_page(GFP_KERNEL);
1103         if (!page)
1104                 goto out;
1105
1106         length = -EFAULT;
1107         if (copy_from_user(page, buf, count))
1108                 goto out;
1109
1110         length = -EINVAL;
1111         if (sscanf(page, "%d", &new_value) != 1)
1112                 goto out;
1113
1114         if (new_value)
1115                 new_value = 1;
1116
1117         bool_pending_values[index] = new_value;
1118         length = count;
1119
1120 out:
1121         mutex_unlock(&sel_mutex);
1122         free_page((unsigned long) page);
1123         return length;
1124 }
1125
1126 static const struct file_operations sel_bool_ops = {
1127         .read           = sel_read_bool,
1128         .write          = sel_write_bool,
1129         .llseek         = generic_file_llseek,
1130 };
1131
1132 static ssize_t sel_commit_bools_write(struct file *filep,
1133                                       const char __user *buf,
1134                                       size_t count, loff_t *ppos)
1135 {
1136         char *page = NULL;
1137         ssize_t length;
1138         int new_value;
1139
1140         mutex_lock(&sel_mutex);
1141
1142         length = task_has_security(current, SECURITY__SETBOOL);
1143         if (length)
1144                 goto out;
1145
1146         length = -ENOMEM;
1147         if (count >= PAGE_SIZE)
1148                 goto out;
1149
1150         /* No partial writes. */
1151         length = -EINVAL;
1152         if (*ppos != 0)
1153                 goto out;
1154
1155         length = -ENOMEM;
1156         page = (char *)get_zeroed_page(GFP_KERNEL);
1157         if (!page)
1158                 goto out;
1159
1160         length = -EFAULT;
1161         if (copy_from_user(page, buf, count))
1162                 goto out;
1163
1164         length = -EINVAL;
1165         if (sscanf(page, "%d", &new_value) != 1)
1166                 goto out;
1167
1168         length = 0;
1169         if (new_value && bool_pending_values)
1170                 length = security_set_bools(bool_num, bool_pending_values);
1171
1172         if (!length)
1173                 length = count;
1174
1175 out:
1176         mutex_unlock(&sel_mutex);
1177         free_page((unsigned long) page);
1178         return length;
1179 }
1180
1181 static const struct file_operations sel_commit_bools_ops = {
1182         .write          = sel_commit_bools_write,
1183         .llseek         = generic_file_llseek,
1184 };
1185
1186 static void sel_remove_entries(struct dentry *de)
1187 {
1188         struct list_head *node;
1189
1190         spin_lock(&de->d_lock);
1191         node = de->d_subdirs.next;
1192         while (node != &de->d_subdirs) {
1193                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1194
1195                 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1196                 list_del_init(node);
1197
1198                 if (d->d_inode) {
1199                         dget_dlock(d);
1200                         spin_unlock(&de->d_lock);
1201                         spin_unlock(&d->d_lock);
1202                         d_delete(d);
1203                         simple_unlink(de->d_inode, d);
1204                         dput(d);
1205                         spin_lock(&de->d_lock);
1206                 } else
1207                         spin_unlock(&d->d_lock);
1208                 node = de->d_subdirs.next;
1209         }
1210
1211         spin_unlock(&de->d_lock);
1212 }
1213
1214 #define BOOL_DIR_NAME "booleans"
1215
1216 static int sel_make_bools(void)
1217 {
1218         int i, ret;
1219         ssize_t len;
1220         struct dentry *dentry = NULL;
1221         struct dentry *dir = bool_dir;
1222         struct inode *inode = NULL;
1223         struct inode_security_struct *isec;
1224         char **names = NULL, *page;
1225         int num;
1226         int *values = NULL;
1227         u32 sid;
1228
1229         /* remove any existing files */
1230         for (i = 0; i < bool_num; i++)
1231                 kfree(bool_pending_names[i]);
1232         kfree(bool_pending_names);
1233         kfree(bool_pending_values);
1234         bool_num = 0;
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 = -ENAMETOOLONG;
1261                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1262                 if (len >= PAGE_SIZE)
1263                         goto out;
1264
1265                 isec = (struct inode_security_struct *)inode->i_security;
1266                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1267                 if (ret)
1268                         goto out;
1269
1270                 isec->sid = sid;
1271                 isec->initialized = 1;
1272                 inode->i_fop = &sel_bool_ops;
1273                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1274                 d_add(dentry, inode);
1275         }
1276         bool_num = num;
1277         bool_pending_names = names;
1278         bool_pending_values = values;
1279
1280         free_page((unsigned long)page);
1281         return 0;
1282 out:
1283         free_page((unsigned long)page);
1284
1285         if (names) {
1286                 for (i = 0; i < num; i++)
1287                         kfree(names[i]);
1288                 kfree(names);
1289         }
1290         kfree(values);
1291         sel_remove_entries(dir);
1292
1293         return ret;
1294 }
1295
1296 #define NULL_FILE_NAME "null"
1297
1298 struct path selinux_null;
1299
1300 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1301                                             size_t count, loff_t *ppos)
1302 {
1303         char tmpbuf[TMPBUFLEN];
1304         ssize_t length;
1305
1306         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1307         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1308 }
1309
1310 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1311                                              const char __user *buf,
1312                                              size_t count, loff_t *ppos)
1313
1314 {
1315         char *page = NULL;
1316         ssize_t ret;
1317         int new_value;
1318
1319         ret = task_has_security(current, SECURITY__SETSECPARAM);
1320         if (ret)
1321                 goto out;
1322
1323         ret = -ENOMEM;
1324         if (count >= PAGE_SIZE)
1325                 goto out;
1326
1327         /* No partial writes. */
1328         ret = -EINVAL;
1329         if (*ppos != 0)
1330                 goto out;
1331
1332         ret = -ENOMEM;
1333         page = (char *)get_zeroed_page(GFP_KERNEL);
1334         if (!page)
1335                 goto out;
1336
1337         ret = -EFAULT;
1338         if (copy_from_user(page, buf, count))
1339                 goto out;
1340
1341         ret = -EINVAL;
1342         if (sscanf(page, "%u", &new_value) != 1)
1343                 goto out;
1344
1345         avc_cache_threshold = new_value;
1346
1347         ret = count;
1348 out:
1349         free_page((unsigned long)page);
1350         return ret;
1351 }
1352
1353 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1354                                        size_t count, loff_t *ppos)
1355 {
1356         char *page;
1357         ssize_t length;
1358
1359         page = (char *)__get_free_page(GFP_KERNEL);
1360         if (!page)
1361                 return -ENOMEM;
1362
1363         length = avc_get_hash_stats(page);
1364         if (length >= 0)
1365                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1366         free_page((unsigned long)page);
1367
1368         return length;
1369 }
1370
1371 static const struct file_operations sel_avc_cache_threshold_ops = {
1372         .read           = sel_read_avc_cache_threshold,
1373         .write          = sel_write_avc_cache_threshold,
1374         .llseek         = generic_file_llseek,
1375 };
1376
1377 static const struct file_operations sel_avc_hash_stats_ops = {
1378         .read           = sel_read_avc_hash_stats,
1379         .llseek         = generic_file_llseek,
1380 };
1381
1382 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1383 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1384 {
1385         int cpu;
1386
1387         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1388                 if (!cpu_possible(cpu))
1389                         continue;
1390                 *idx = cpu + 1;
1391                 return &per_cpu(avc_cache_stats, cpu);
1392         }
1393         return NULL;
1394 }
1395
1396 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1397 {
1398         loff_t n = *pos - 1;
1399
1400         if (*pos == 0)
1401                 return SEQ_START_TOKEN;
1402
1403         return sel_avc_get_stat_idx(&n);
1404 }
1405
1406 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1407 {
1408         return sel_avc_get_stat_idx(pos);
1409 }
1410
1411 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1412 {
1413         struct avc_cache_stats *st = v;
1414
1415         if (v == SEQ_START_TOKEN)
1416                 seq_printf(seq, "lookups hits misses allocations reclaims "
1417                            "frees\n");
1418         else {
1419                 unsigned int lookups = st->lookups;
1420                 unsigned int misses = st->misses;
1421                 unsigned int hits = lookups - misses;
1422                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1423                            hits, misses, st->allocations,
1424                            st->reclaims, st->frees);
1425         }
1426         return 0;
1427 }
1428
1429 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1430 { }
1431
1432 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1433         .start          = sel_avc_stats_seq_start,
1434         .next           = sel_avc_stats_seq_next,
1435         .show           = sel_avc_stats_seq_show,
1436         .stop           = sel_avc_stats_seq_stop,
1437 };
1438
1439 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1440 {
1441         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1442 }
1443
1444 static const struct file_operations sel_avc_cache_stats_ops = {
1445         .open           = sel_open_avc_cache_stats,
1446         .read           = seq_read,
1447         .llseek         = seq_lseek,
1448         .release        = seq_release,
1449 };
1450 #endif
1451
1452 static int sel_make_avc_files(struct dentry *dir)
1453 {
1454         int i;
1455         static struct tree_descr files[] = {
1456                 { "cache_threshold",
1457                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1458                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1459 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1460                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1461 #endif
1462         };
1463
1464         for (i = 0; i < ARRAY_SIZE(files); i++) {
1465                 struct inode *inode;
1466                 struct dentry *dentry;
1467
1468                 dentry = d_alloc_name(dir, files[i].name);
1469                 if (!dentry)
1470                         return -ENOMEM;
1471
1472                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1473                 if (!inode)
1474                         return -ENOMEM;
1475
1476                 inode->i_fop = files[i].ops;
1477                 inode->i_ino = ++sel_last_ino;
1478                 d_add(dentry, inode);
1479         }
1480
1481         return 0;
1482 }
1483
1484 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1485                                 size_t count, loff_t *ppos)
1486 {
1487         char *con;
1488         u32 sid, len;
1489         ssize_t ret;
1490
1491         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1492         ret = security_sid_to_context(sid, &con, &len);
1493         if (ret)
1494                 return ret;
1495
1496         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1497         kfree(con);
1498         return ret;
1499 }
1500
1501 static const struct file_operations sel_initcon_ops = {
1502         .read           = sel_read_initcon,
1503         .llseek         = generic_file_llseek,
1504 };
1505
1506 static int sel_make_initcon_files(struct dentry *dir)
1507 {
1508         int i;
1509
1510         for (i = 1; i <= SECINITSID_NUM; i++) {
1511                 struct inode *inode;
1512                 struct dentry *dentry;
1513                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1514                 if (!dentry)
1515                         return -ENOMEM;
1516
1517                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1518                 if (!inode)
1519                         return -ENOMEM;
1520
1521                 inode->i_fop = &sel_initcon_ops;
1522                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1523                 d_add(dentry, inode);
1524         }
1525
1526         return 0;
1527 }
1528
1529 static inline unsigned long sel_class_to_ino(u16 class)
1530 {
1531         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1532 }
1533
1534 static inline u16 sel_ino_to_class(unsigned long ino)
1535 {
1536         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1537 }
1538
1539 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1540 {
1541         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1542 }
1543
1544 static inline u32 sel_ino_to_perm(unsigned long ino)
1545 {
1546         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1547 }
1548
1549 static ssize_t sel_read_class(struct file *file, char __user *buf,
1550                                 size_t count, loff_t *ppos)
1551 {
1552         unsigned long ino = file_inode(file)->i_ino;
1553         char res[TMPBUFLEN];
1554         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1555         return simple_read_from_buffer(buf, count, ppos, res, len);
1556 }
1557
1558 static const struct file_operations sel_class_ops = {
1559         .read           = sel_read_class,
1560         .llseek         = generic_file_llseek,
1561 };
1562
1563 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1564                                 size_t count, loff_t *ppos)
1565 {
1566         unsigned long ino = file_inode(file)->i_ino;
1567         char res[TMPBUFLEN];
1568         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1569         return simple_read_from_buffer(buf, count, ppos, res, len);
1570 }
1571
1572 static const struct file_operations sel_perm_ops = {
1573         .read           = sel_read_perm,
1574         .llseek         = generic_file_llseek,
1575 };
1576
1577 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1578                                   size_t count, loff_t *ppos)
1579 {
1580         int value;
1581         char tmpbuf[TMPBUFLEN];
1582         ssize_t length;
1583         unsigned long i_ino = file_inode(file)->i_ino;
1584
1585         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1586         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1587
1588         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1589 }
1590
1591 static const struct file_operations sel_policycap_ops = {
1592         .read           = sel_read_policycap,
1593         .llseek         = generic_file_llseek,
1594 };
1595
1596 static int sel_make_perm_files(char *objclass, int classvalue,
1597                                 struct dentry *dir)
1598 {
1599         int i, rc, nperms;
1600         char **perms;
1601
1602         rc = security_get_permissions(objclass, &perms, &nperms);
1603         if (rc)
1604                 return rc;
1605
1606         for (i = 0; i < nperms; i++) {
1607                 struct inode *inode;
1608                 struct dentry *dentry;
1609
1610                 rc = -ENOMEM;
1611                 dentry = d_alloc_name(dir, perms[i]);
1612                 if (!dentry)
1613                         goto out;
1614
1615                 rc = -ENOMEM;
1616                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1617                 if (!inode)
1618                         goto out;
1619
1620                 inode->i_fop = &sel_perm_ops;
1621                 /* i+1 since perm values are 1-indexed */
1622                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1623                 d_add(dentry, inode);
1624         }
1625         rc = 0;
1626 out:
1627         for (i = 0; i < nperms; i++)
1628                 kfree(perms[i]);
1629         kfree(perms);
1630         return rc;
1631 }
1632
1633 static int sel_make_class_dir_entries(char *classname, int index,
1634                                         struct dentry *dir)
1635 {
1636         struct dentry *dentry = NULL;
1637         struct inode *inode = NULL;
1638         int rc;
1639
1640         dentry = d_alloc_name(dir, "index");
1641         if (!dentry)
1642                 return -ENOMEM;
1643
1644         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1645         if (!inode)
1646                 return -ENOMEM;
1647
1648         inode->i_fop = &sel_class_ops;
1649         inode->i_ino = sel_class_to_ino(index);
1650         d_add(dentry, inode);
1651
1652         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1653         if (IS_ERR(dentry))
1654                 return PTR_ERR(dentry);
1655
1656         rc = sel_make_perm_files(classname, index, dentry);
1657
1658         return rc;
1659 }
1660
1661 static void sel_remove_classes(void)
1662 {
1663         struct list_head *class_node;
1664
1665         list_for_each(class_node, &class_dir->d_subdirs) {
1666                 struct dentry *class_subdir = list_entry(class_node,
1667                                         struct dentry, d_u.d_child);
1668                 struct list_head *class_subdir_node;
1669
1670                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1671                         struct dentry *d = list_entry(class_subdir_node,
1672                                                 struct dentry, d_u.d_child);
1673
1674                         if (d->d_inode)
1675                                 if (d->d_inode->i_mode & S_IFDIR)
1676                                         sel_remove_entries(d);
1677                 }
1678
1679                 sel_remove_entries(class_subdir);
1680         }
1681
1682         sel_remove_entries(class_dir);
1683 }
1684
1685 static int sel_make_classes(void)
1686 {
1687         int rc, nclasses, i;
1688         char **classes;
1689
1690         /* delete any existing entries */
1691         sel_remove_classes();
1692
1693         rc = security_get_classes(&classes, &nclasses);
1694         if (rc)
1695                 return rc;
1696
1697         /* +2 since classes are 1-indexed */
1698         last_class_ino = sel_class_to_ino(nclasses + 2);
1699
1700         for (i = 0; i < nclasses; i++) {
1701                 struct dentry *class_name_dir;
1702
1703                 class_name_dir = sel_make_dir(class_dir, classes[i],
1704                                 &last_class_ino);
1705                 if (IS_ERR(class_name_dir)) {
1706                         rc = PTR_ERR(class_name_dir);
1707                         goto out;
1708                 }
1709
1710                 /* i+1 since class values are 1-indexed */
1711                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1712                                 class_name_dir);
1713                 if (rc)
1714                         goto out;
1715         }
1716         rc = 0;
1717 out:
1718         for (i = 0; i < nclasses; i++)
1719                 kfree(classes[i]);
1720         kfree(classes);
1721         return rc;
1722 }
1723
1724 static int sel_make_policycap(void)
1725 {
1726         unsigned int iter;
1727         struct dentry *dentry = NULL;
1728         struct inode *inode = NULL;
1729
1730         sel_remove_entries(policycap_dir);
1731
1732         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1733                 if (iter < ARRAY_SIZE(policycap_names))
1734                         dentry = d_alloc_name(policycap_dir,
1735                                               policycap_names[iter]);
1736                 else
1737                         dentry = d_alloc_name(policycap_dir, "unknown");
1738
1739                 if (dentry == NULL)
1740                         return -ENOMEM;
1741
1742                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1743                 if (inode == NULL)
1744                         return -ENOMEM;
1745
1746                 inode->i_fop = &sel_policycap_ops;
1747                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1748                 d_add(dentry, inode);
1749         }
1750
1751         return 0;
1752 }
1753
1754 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1755                         unsigned long *ino)
1756 {
1757         struct dentry *dentry = d_alloc_name(dir, name);
1758         struct inode *inode;
1759
1760         if (!dentry)
1761                 return ERR_PTR(-ENOMEM);
1762
1763         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1764         if (!inode) {
1765                 dput(dentry);
1766                 return ERR_PTR(-ENOMEM);
1767         }
1768
1769         inode->i_op = &simple_dir_inode_operations;
1770         inode->i_fop = &simple_dir_operations;
1771         inode->i_ino = ++(*ino);
1772         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1773         inc_nlink(inode);
1774         d_add(dentry, inode);
1775         /* bump link count on parent directory, too */
1776         inc_nlink(dir->d_inode);
1777
1778         return dentry;
1779 }
1780
1781 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1782 {
1783         int ret;
1784         struct dentry *dentry;
1785         struct inode *inode;
1786         struct inode_security_struct *isec;
1787
1788         static struct tree_descr selinux_files[] = {
1789                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1790                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1791                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1792                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1793                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1794                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1795                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1796                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1797                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1798                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1799                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1800                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1801                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1802                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1803                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1804                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1805                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1806                 /* last one */ {""}
1807         };
1808         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1809         if (ret)
1810                 goto err;
1811
1812         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1813         if (IS_ERR(bool_dir)) {
1814                 ret = PTR_ERR(bool_dir);
1815                 bool_dir = NULL;
1816                 goto err;
1817         }
1818
1819         ret = -ENOMEM;
1820         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1821         if (!dentry)
1822                 goto err;
1823
1824         ret = -ENOMEM;
1825         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1826         if (!inode)
1827                 goto err;
1828
1829         inode->i_ino = ++sel_last_ino;
1830         isec = (struct inode_security_struct *)inode->i_security;
1831         isec->sid = SECINITSID_DEVNULL;
1832         isec->sclass = SECCLASS_CHR_FILE;
1833         isec->initialized = 1;
1834
1835         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1836         d_add(dentry, inode);
1837         selinux_null.dentry = dentry;
1838
1839         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1840         if (IS_ERR(dentry)) {
1841                 ret = PTR_ERR(dentry);
1842                 goto err;
1843         }
1844
1845         ret = sel_make_avc_files(dentry);
1846         if (ret)
1847                 goto err;
1848
1849         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1850         if (IS_ERR(dentry)) {
1851                 ret = PTR_ERR(dentry);
1852                 goto err;
1853         }
1854
1855         ret = sel_make_initcon_files(dentry);
1856         if (ret)
1857                 goto err;
1858
1859         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1860         if (IS_ERR(class_dir)) {
1861                 ret = PTR_ERR(class_dir);
1862                 class_dir = NULL;
1863                 goto err;
1864         }
1865
1866         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1867         if (IS_ERR(policycap_dir)) {
1868                 ret = PTR_ERR(policycap_dir);
1869                 policycap_dir = NULL;
1870                 goto err;
1871         }
1872         return 0;
1873 err:
1874         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1875                 __func__);
1876         return ret;
1877 }
1878
1879 static struct dentry *sel_mount(struct file_system_type *fs_type,
1880                       int flags, const char *dev_name, void *data)
1881 {
1882         return mount_single(fs_type, flags, data, sel_fill_super);
1883 }
1884
1885 static struct file_system_type sel_fs_type = {
1886         .name           = "selinuxfs",
1887         .mount          = sel_mount,
1888         .kill_sb        = kill_litter_super,
1889 };
1890
1891 struct vfsmount *selinuxfs_mount;
1892 static struct kobject *selinuxfs_kobj;
1893
1894 static int __init init_sel_fs(void)
1895 {
1896         int err;
1897
1898         if (!selinux_enabled)
1899                 return 0;
1900
1901         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1902         if (!selinuxfs_kobj)
1903                 return -ENOMEM;
1904
1905         err = register_filesystem(&sel_fs_type);
1906         if (err) {
1907                 kobject_put(selinuxfs_kobj);
1908                 return err;
1909         }
1910
1911         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1912         if (IS_ERR(selinuxfs_mount)) {
1913                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1914                 err = PTR_ERR(selinuxfs_mount);
1915                 selinuxfs_mount = NULL;
1916         }
1917
1918         return err;
1919 }
1920
1921 __initcall(init_sel_fs);
1922
1923 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1924 void exit_sel_fs(void)
1925 {
1926         kobject_put(selinuxfs_kobj);
1927         kern_unmount(selinuxfs_mount);
1928         unregister_filesystem(&sel_fs_type);
1929 }
1930 #endif