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 = filp->f_path.dentry->d_inode->i_ino;
 206         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 207                 security_get_reject_unknown() : !security_get_allow_unknown();
 208
 209         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 210         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 211 }
 212
 213 static const struct file_operations sel_handle_unknown_ops = {
 214         .read           = sel_read_handle_unknown,
 215         .llseek         = generic_file_llseek,
 216 };
 217
 218 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 219 {
 220         struct page    *status = selinux_kernel_status_page();
 221
 222         if (!status)
 223                 return -ENOMEM;
 224
 225         filp->private_data = status;
 226
 227         return 0;
 228 }
 229
 230 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 231                                       size_t count, loff_t *ppos)
 232 {
 233         struct page    *status = filp->private_data;
 234
 235         BUG_ON(!status);
 236
 237         return simple_read_from_buffer(buf, count, ppos,
 238                                        page_address(status),
 239                                        sizeof(struct selinux_kernel_status));
 240 }
 241
 242 static int sel_mmap_handle_status(struct file *filp,
 243                                   struct vm_area_struct *vma)
 244 {
 245         struct page    *status = filp->private_data;
 246         unsigned long   size = vma->vm_end - vma->vm_start;
 247
 248         BUG_ON(!status);
 249
 250         /* only allows one page from the head */
 251         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 252                 return -EIO;
 253         /* disallow writable mapping */
 254         if (vma->vm_flags & VM_WRITE)
 255                 return -EPERM;
 256         /* disallow mprotect() turns it into writable */
 257         vma->vm_flags &= ~VM_MAYWRITE;
 258
 259         return remap_pfn_range(vma, vma->vm_start,
 260                                page_to_pfn(status),
 261                                size, vma->vm_page_prot);
 262 }
 263
 264 static const struct file_operations sel_handle_status_ops = {
 265         .open           = sel_open_handle_status,
 266         .read           = sel_read_handle_status,
 267         .mmap           = sel_mmap_handle_status,
 268         .llseek         = generic_file_llseek,
 269 };
 270
 271 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 272 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 273                                  size_t count, loff_t *ppos)
 274
 275 {
 276         char *page = NULL;
 277         ssize_t length;
 278         int new_value;
 279
 280         length = -ENOMEM;
 281         if (count >= PAGE_SIZE)
 282                 goto out;
 283
 284         /* No partial writes. */
 285         length = -EINVAL;
 286         if (*ppos != 0)
 287                 goto out;
 288
 289         length = -ENOMEM;
 290         page = (char *)get_zeroed_page(GFP_KERNEL);
 291         if (!page)
 292                 goto out;
 293
 294         length = -EFAULT;
 295         if (copy_from_user(page, buf, count))
 296                 goto out;
 297
 298         length = -EINVAL;
 299         if (sscanf(page, "%d", &new_value) != 1)
 300                 goto out;
 301
 302         if (new_value) {
 303                 length = selinux_disable();
 304                 if (length)
 305                         goto out;
 306                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 307                         "selinux=0 auid=%u ses=%u",
 308                         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->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         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         struct inode *inode = filep->f_path.dentry->d_inode;
1046         unsigned index = inode->i_ino & SEL_INO_MASK;
1047         const char *name = filep->f_path.dentry->d_name.name;
1048
1049         mutex_lock(&sel_mutex);
1050
1051         ret = -EINVAL;
1052         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1053                 goto out;
1054
1055         ret = -ENOMEM;
1056         page = (char *)get_zeroed_page(GFP_KERNEL);
1057         if (!page)
1058                 goto out;
1059
1060         cur_enforcing = security_get_bool_value(index);
1061         if (cur_enforcing < 0) {
1062                 ret = cur_enforcing;
1063                 goto out;
1064         }
1065         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1066                           bool_pending_values[index]);
1067         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1068 out:
1069         mutex_unlock(&sel_mutex);
1070         free_page((unsigned long)page);
1071         return ret;
1072 }
1073
1074 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1075                               size_t count, loff_t *ppos)
1076 {
1077         char *page = NULL;
1078         ssize_t length;
1079         int new_value;
1080         struct inode *inode = filep->f_path.dentry->d_inode;
1081         unsigned index = inode->i_ino & SEL_INO_MASK;
1082         const char *name = filep->f_path.dentry->d_name.name;
1083
1084         mutex_lock(&sel_mutex);
1085
1086         length = task_has_security(current, SECURITY__SETBOOL);
1087         if (length)
1088                 goto out;
1089
1090         length = -EINVAL;
1091         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1092                 goto out;
1093
1094         length = -ENOMEM;
1095         if (count >= PAGE_SIZE)
1096                 goto out;
1097
1098         /* No partial writes. */
1099         length = -EINVAL;
1100         if (*ppos != 0)
1101                 goto out;
1102
1103         length = -ENOMEM;
1104         page = (char *)get_zeroed_page(GFP_KERNEL);
1105         if (!page)
1106                 goto out;
1107
1108         length = -EFAULT;
1109         if (copy_from_user(page, buf, count))
1110                 goto out;
1111
1112         length = -EINVAL;
1113         if (sscanf(page, "%d", &new_value) != 1)
1114                 goto out;
1115
1116         if (new_value)
1117                 new_value = 1;
1118
1119         bool_pending_values[index] = new_value;
1120         length = count;
1121
1122 out:
1123         mutex_unlock(&sel_mutex);
1124         free_page((unsigned long) page);
1125         return length;
1126 }
1127
1128 static const struct file_operations sel_bool_ops = {
1129         .read           = sel_read_bool,
1130         .write          = sel_write_bool,
1131         .llseek         = generic_file_llseek,
1132 };
1133
1134 static ssize_t sel_commit_bools_write(struct file *filep,
1135                                       const char __user *buf,
1136                                       size_t count, loff_t *ppos)
1137 {
1138         char *page = NULL;
1139         ssize_t length;
1140         int new_value;
1141
1142         mutex_lock(&sel_mutex);
1143
1144         length = task_has_security(current, SECURITY__SETBOOL);
1145         if (length)
1146                 goto out;
1147
1148         length = -ENOMEM;
1149         if (count >= PAGE_SIZE)
1150                 goto out;
1151
1152         /* No partial writes. */
1153         length = -EINVAL;
1154         if (*ppos != 0)
1155                 goto out;
1156
1157         length = -ENOMEM;
1158         page = (char *)get_zeroed_page(GFP_KERNEL);
1159         if (!page)
1160                 goto out;
1161
1162         length = -EFAULT;
1163         if (copy_from_user(page, buf, count))
1164                 goto out;
1165
1166         length = -EINVAL;
1167         if (sscanf(page, "%d", &new_value) != 1)
1168                 goto out;
1169
1170         length = 0;
1171         if (new_value && bool_pending_values)
1172                 length = security_set_bools(bool_num, bool_pending_values);
1173
1174         if (!length)
1175                 length = count;
1176
1177 out:
1178         mutex_unlock(&sel_mutex);
1179         free_page((unsigned long) page);
1180         return length;
1181 }
1182
1183 static const struct file_operations sel_commit_bools_ops = {
1184         .write          = sel_commit_bools_write,
1185         .llseek         = generic_file_llseek,
1186 };
1187
1188 static void sel_remove_entries(struct dentry *de)
1189 {
1190         struct list_head *node;
1191
1192         spin_lock(&de->d_lock);
1193         node = de->d_subdirs.next;
1194         while (node != &de->d_subdirs) {
1195                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1196
1197                 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1198                 list_del_init(node);
1199
1200                 if (d->d_inode) {
1201                         dget_dlock(d);
1202                         spin_unlock(&de->d_lock);
1203                         spin_unlock(&d->d_lock);
1204                         d_delete(d);
1205                         simple_unlink(de->d_inode, d);
1206                         dput(d);
1207                         spin_lock(&de->d_lock);
1208                 } else
1209                         spin_unlock(&d->d_lock);
1210                 node = de->d_subdirs.next;
1211         }
1212
1213         spin_unlock(&de->d_lock);
1214 }
1215
1216 #define BOOL_DIR_NAME "booleans"
1217
1218 static int sel_make_bools(void)
1219 {
1220         int i, ret;
1221         ssize_t len;
1222         struct dentry *dentry = NULL;
1223         struct dentry *dir = bool_dir;
1224         struct inode *inode = NULL;
1225         struct inode_security_struct *isec;
1226         char **names = NULL, *page;
1227         int num;
1228         int *values = NULL;
1229         u32 sid;
1230
1231         /* remove any existing files */
1232         for (i = 0; i < bool_num; i++)
1233                 kfree(bool_pending_names[i]);
1234         kfree(bool_pending_names);
1235         kfree(bool_pending_values);
1236         bool_num = 0;
1237         bool_pending_names = NULL;
1238         bool_pending_values = NULL;
1239
1240         sel_remove_entries(dir);
1241
1242         ret = -ENOMEM;
1243         page = (char *)get_zeroed_page(GFP_KERNEL);
1244         if (!page)
1245                 goto out;
1246
1247         ret = security_get_bools(&num, &names, &values);
1248         if (ret)
1249                 goto out;
1250
1251         for (i = 0; i < num; i++) {
1252                 ret = -ENOMEM;
1253                 dentry = d_alloc_name(dir, names[i]);
1254                 if (!dentry)
1255                         goto out;
1256
1257                 ret = -ENOMEM;
1258                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1259                 if (!inode)
1260                         goto out;
1261
1262                 ret = -ENAMETOOLONG;
1263                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1264                 if (len >= PAGE_SIZE)
1265                         goto out;
1266
1267                 isec = (struct inode_security_struct *)inode->i_security;
1268                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1269                 if (ret)
1270                         goto out;
1271
1272                 isec->sid = sid;
1273                 isec->initialized = 1;
1274                 inode->i_fop = &sel_bool_ops;
1275                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1276                 d_add(dentry, inode);
1277         }
1278         bool_num = num;
1279         bool_pending_names = names;
1280         bool_pending_values = values;
1281
1282         free_page((unsigned long)page);
1283         return 0;
1284 out:
1285         free_page((unsigned long)page);
1286
1287         if (names) {
1288                 for (i = 0; i < num; i++)
1289                         kfree(names[i]);
1290                 kfree(names);
1291         }
1292         kfree(values);
1293         sel_remove_entries(dir);
1294
1295         return ret;
1296 }
1297
1298 #define NULL_FILE_NAME "null"
1299
1300 struct path selinux_null;
1301
1302 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1303                                             size_t count, loff_t *ppos)
1304 {
1305         char tmpbuf[TMPBUFLEN];
1306         ssize_t length;
1307
1308         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1309         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1310 }
1311
1312 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1313                                              const char __user *buf,
1314                                              size_t count, loff_t *ppos)
1315
1316 {
1317         char *page = NULL;
1318         ssize_t ret;
1319         int new_value;
1320
1321         ret = task_has_security(current, SECURITY__SETSECPARAM);
1322         if (ret)
1323                 goto out;
1324
1325         ret = -ENOMEM;
1326         if (count >= PAGE_SIZE)
1327                 goto out;
1328
1329         /* No partial writes. */
1330         ret = -EINVAL;
1331         if (*ppos != 0)
1332                 goto out;
1333
1334         ret = -ENOMEM;
1335         page = (char *)get_zeroed_page(GFP_KERNEL);
1336         if (!page)
1337                 goto out;
1338
1339         ret = -EFAULT;
1340         if (copy_from_user(page, buf, count))
1341                 goto out;
1342
1343         ret = -EINVAL;
1344         if (sscanf(page, "%u", &new_value) != 1)
1345                 goto out;
1346
1347         avc_cache_threshold = new_value;
1348
1349         ret = count;
1350 out:
1351         free_page((unsigned long)page);
1352         return ret;
1353 }
1354
1355 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1356                                        size_t count, loff_t *ppos)
1357 {
1358         char *page;
1359         ssize_t length;
1360
1361         page = (char *)__get_free_page(GFP_KERNEL);
1362         if (!page)
1363                 return -ENOMEM;
1364
1365         length = avc_get_hash_stats(page);
1366         if (length >= 0)
1367                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1368         free_page((unsigned long)page);
1369
1370         return length;
1371 }
1372
1373 static const struct file_operations sel_avc_cache_threshold_ops = {
1374         .read           = sel_read_avc_cache_threshold,
1375         .write          = sel_write_avc_cache_threshold,
1376         .llseek         = generic_file_llseek,
1377 };
1378
1379 static const struct file_operations sel_avc_hash_stats_ops = {
1380         .read           = sel_read_avc_hash_stats,
1381         .llseek         = generic_file_llseek,
1382 };
1383
1384 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1385 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1386 {
1387         int cpu;
1388
1389         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1390                 if (!cpu_possible(cpu))
1391                         continue;
1392                 *idx = cpu + 1;
1393                 return &per_cpu(avc_cache_stats, cpu);
1394         }
1395         return NULL;
1396 }
1397
1398 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1399 {
1400         loff_t n = *pos - 1;
1401
1402         if (*pos == 0)
1403                 return SEQ_START_TOKEN;
1404
1405         return sel_avc_get_stat_idx(&n);
1406 }
1407
1408 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1409 {
1410         return sel_avc_get_stat_idx(pos);
1411 }
1412
1413 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1414 {
1415         struct avc_cache_stats *st = v;
1416
1417         if (v == SEQ_START_TOKEN)
1418                 seq_printf(seq, "lookups hits misses allocations reclaims "
1419                            "frees\n");
1420         else {
1421                 unsigned int lookups = st->lookups;
1422                 unsigned int misses = st->misses;
1423                 unsigned int hits = lookups - misses;
1424                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1425                            hits, misses, st->allocations,
1426                            st->reclaims, st->frees);
1427         }
1428         return 0;
1429 }
1430
1431 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1432 { }
1433
1434 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1435         .start          = sel_avc_stats_seq_start,
1436         .next           = sel_avc_stats_seq_next,
1437         .show           = sel_avc_stats_seq_show,
1438         .stop           = sel_avc_stats_seq_stop,
1439 };
1440
1441 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1442 {
1443         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1444 }
1445
1446 static const struct file_operations sel_avc_cache_stats_ops = {
1447         .open           = sel_open_avc_cache_stats,
1448         .read           = seq_read,
1449         .llseek         = seq_lseek,
1450         .release        = seq_release,
1451 };
1452 #endif
1453
1454 static int sel_make_avc_files(struct dentry *dir)
1455 {
1456         int i;
1457         static struct tree_descr files[] = {
1458                 { "cache_threshold",
1459                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1460                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1461 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1462                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1463 #endif
1464         };
1465
1466         for (i = 0; i < ARRAY_SIZE(files); i++) {
1467                 struct inode *inode;
1468                 struct dentry *dentry;
1469
1470                 dentry = d_alloc_name(dir, files[i].name);
1471                 if (!dentry)
1472                         return -ENOMEM;
1473
1474                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1475                 if (!inode)
1476                         return -ENOMEM;
1477
1478                 inode->i_fop = files[i].ops;
1479                 inode->i_ino = ++sel_last_ino;
1480                 d_add(dentry, inode);
1481         }
1482
1483         return 0;
1484 }
1485
1486 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1487                                 size_t count, loff_t *ppos)
1488 {
1489         struct inode *inode;
1490         char *con;
1491         u32 sid, len;
1492         ssize_t ret;
1493
1494         inode = file->f_path.dentry->d_inode;
1495         sid = inode->i_ino&SEL_INO_MASK;
1496         ret = security_sid_to_context(sid, &con, &len);
1497         if (ret)
1498                 return ret;
1499
1500         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1501         kfree(con);
1502         return ret;
1503 }
1504
1505 static const struct file_operations sel_initcon_ops = {
1506         .read           = sel_read_initcon,
1507         .llseek         = generic_file_llseek,
1508 };
1509
1510 static int sel_make_initcon_files(struct dentry *dir)
1511 {
1512         int i;
1513
1514         for (i = 1; i <= SECINITSID_NUM; i++) {
1515                 struct inode *inode;
1516                 struct dentry *dentry;
1517                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1518                 if (!dentry)
1519                         return -ENOMEM;
1520
1521                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1522                 if (!inode)
1523                         return -ENOMEM;
1524
1525                 inode->i_fop = &sel_initcon_ops;
1526                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1527                 d_add(dentry, inode);
1528         }
1529
1530         return 0;
1531 }
1532
1533 static inline unsigned long sel_class_to_ino(u16 class)
1534 {
1535         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1536 }
1537
1538 static inline u16 sel_ino_to_class(unsigned long ino)
1539 {
1540         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1541 }
1542
1543 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1544 {
1545         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1546 }
1547
1548 static inline u32 sel_ino_to_perm(unsigned long ino)
1549 {
1550         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1551 }
1552
1553 static ssize_t sel_read_class(struct file *file, char __user *buf,
1554                                 size_t count, loff_t *ppos)
1555 {
1556         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1557         char res[TMPBUFLEN];
1558         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1559         return simple_read_from_buffer(buf, count, ppos, res, len);
1560 }
1561
1562 static const struct file_operations sel_class_ops = {
1563         .read           = sel_read_class,
1564         .llseek         = generic_file_llseek,
1565 };
1566
1567 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1568                                 size_t count, loff_t *ppos)
1569 {
1570         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1571         char res[TMPBUFLEN];
1572         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1573         return simple_read_from_buffer(buf, count, ppos, res, len);
1574 }
1575
1576 static const struct file_operations sel_perm_ops = {
1577         .read           = sel_read_perm,
1578         .llseek         = generic_file_llseek,
1579 };
1580
1581 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1582                                   size_t count, loff_t *ppos)
1583 {
1584         int value;
1585         char tmpbuf[TMPBUFLEN];
1586         ssize_t length;
1587         unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1588
1589         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1590         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1591
1592         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1593 }
1594
1595 static const struct file_operations sel_policycap_ops = {
1596         .read           = sel_read_policycap,
1597         .llseek         = generic_file_llseek,
1598 };
1599
1600 static int sel_make_perm_files(char *objclass, int classvalue,
1601                                 struct dentry *dir)
1602 {
1603         int i, rc, nperms;
1604         char **perms;
1605
1606         rc = security_get_permissions(objclass, &perms, &nperms);
1607         if (rc)
1608                 return rc;
1609
1610         for (i = 0; i < nperms; i++) {
1611                 struct inode *inode;
1612                 struct dentry *dentry;
1613
1614                 rc = -ENOMEM;
1615                 dentry = d_alloc_name(dir, perms[i]);
1616                 if (!dentry)
1617                         goto out;
1618
1619                 rc = -ENOMEM;
1620                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1621                 if (!inode)
1622                         goto out;
1623
1624                 inode->i_fop = &sel_perm_ops;
1625                 /* i+1 since perm values are 1-indexed */
1626                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1627                 d_add(dentry, inode);
1628         }
1629         rc = 0;
1630 out:
1631         for (i = 0; i < nperms; i++)
1632                 kfree(perms[i]);
1633         kfree(perms);
1634         return rc;
1635 }
1636
1637 static int sel_make_class_dir_entries(char *classname, int index,
1638                                         struct dentry *dir)
1639 {
1640         struct dentry *dentry = NULL;
1641         struct inode *inode = NULL;
1642         int rc;
1643
1644         dentry = d_alloc_name(dir, "index");
1645         if (!dentry)
1646                 return -ENOMEM;
1647
1648         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1649         if (!inode)
1650                 return -ENOMEM;
1651
1652         inode->i_fop = &sel_class_ops;
1653         inode->i_ino = sel_class_to_ino(index);
1654         d_add(dentry, inode);
1655
1656         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1657         if (IS_ERR(dentry))
1658                 return PTR_ERR(dentry);
1659
1660         rc = sel_make_perm_files(classname, index, dentry);
1661
1662         return rc;
1663 }
1664
1665 static void sel_remove_classes(void)
1666 {
1667         struct list_head *class_node;
1668
1669         list_for_each(class_node, &class_dir->d_subdirs) {
1670                 struct dentry *class_subdir = list_entry(class_node,
1671                                         struct dentry, d_u.d_child);
1672                 struct list_head *class_subdir_node;
1673
1674                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1675                         struct dentry *d = list_entry(class_subdir_node,
1676                                                 struct dentry, d_u.d_child);
1677
1678                         if (d->d_inode)
1679                                 if (d->d_inode->i_mode & S_IFDIR)
1680                                         sel_remove_entries(d);
1681                 }
1682
1683                 sel_remove_entries(class_subdir);
1684         }
1685
1686         sel_remove_entries(class_dir);
1687 }
1688
1689 static int sel_make_classes(void)
1690 {
1691         int rc, nclasses, i;
1692         char **classes;
1693
1694         /* delete any existing entries */
1695         sel_remove_classes();
1696
1697         rc = security_get_classes(&classes, &nclasses);
1698         if (rc)
1699                 return rc;
1700
1701         /* +2 since classes are 1-indexed */
1702         last_class_ino = sel_class_to_ino(nclasses + 2);
1703
1704         for (i = 0; i < nclasses; i++) {
1705                 struct dentry *class_name_dir;
1706
1707                 class_name_dir = sel_make_dir(class_dir, classes[i],
1708                                 &last_class_ino);
1709                 if (IS_ERR(class_name_dir)) {
1710                         rc = PTR_ERR(class_name_dir);
1711                         goto out;
1712                 }
1713
1714                 /* i+1 since class values are 1-indexed */
1715                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1716                                 class_name_dir);
1717                 if (rc)
1718                         goto out;
1719         }
1720         rc = 0;
1721 out:
1722         for (i = 0; i < nclasses; i++)
1723                 kfree(classes[i]);
1724         kfree(classes);
1725         return rc;
1726 }
1727
1728 static int sel_make_policycap(void)
1729 {
1730         unsigned int iter;
1731         struct dentry *dentry = NULL;
1732         struct inode *inode = NULL;
1733
1734         sel_remove_entries(policycap_dir);
1735
1736         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1737                 if (iter < ARRAY_SIZE(policycap_names))
1738                         dentry = d_alloc_name(policycap_dir,
1739                                               policycap_names[iter]);
1740                 else
1741                         dentry = d_alloc_name(policycap_dir, "unknown");
1742
1743                 if (dentry == NULL)
1744                         return -ENOMEM;
1745
1746                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1747                 if (inode == NULL)
1748                         return -ENOMEM;
1749
1750                 inode->i_fop = &sel_policycap_ops;
1751                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1752                 d_add(dentry, inode);
1753         }
1754
1755         return 0;
1756 }
1757
1758 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1759                         unsigned long *ino)
1760 {
1761         struct dentry *dentry = d_alloc_name(dir, name);
1762         struct inode *inode;
1763
1764         if (!dentry)
1765                 return ERR_PTR(-ENOMEM);
1766
1767         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1768         if (!inode) {
1769                 dput(dentry);
1770                 return ERR_PTR(-ENOMEM);
1771         }
1772
1773         inode->i_op = &simple_dir_inode_operations;
1774         inode->i_fop = &simple_dir_operations;
1775         inode->i_ino = ++(*ino);
1776         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1777         inc_nlink(inode);
1778         d_add(dentry, inode);
1779         /* bump link count on parent directory, too */
1780         inc_nlink(dir->d_inode);
1781
1782         return dentry;
1783 }
1784
1785 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1786 {
1787         int ret;
1788         struct dentry *dentry;
1789         struct inode *inode;
1790         struct inode_security_struct *isec;
1791
1792         static struct tree_descr selinux_files[] = {
1793                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1794                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1795                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1796                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1797                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1798                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1799                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1800                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1801                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1802                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1803                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1804                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1805                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1806                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1807                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1808                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1809                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1810                 /* last one */ {""}
1811         };
1812         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1813         if (ret)
1814                 goto err;
1815
1816         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1817         if (IS_ERR(bool_dir)) {
1818                 ret = PTR_ERR(bool_dir);
1819                 bool_dir = NULL;
1820                 goto err;
1821         }
1822
1823         ret = -ENOMEM;
1824         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1825         if (!dentry)
1826                 goto err;
1827
1828         ret = -ENOMEM;
1829         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1830         if (!inode)
1831                 goto err;
1832
1833         inode->i_ino = ++sel_last_ino;
1834         isec = (struct inode_security_struct *)inode->i_security;
1835         isec->sid = SECINITSID_DEVNULL;
1836         isec->sclass = SECCLASS_CHR_FILE;
1837         isec->initialized = 1;
1838
1839         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1840         d_add(dentry, inode);
1841         selinux_null.dentry = dentry;
1842
1843         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1844         if (IS_ERR(dentry)) {
1845                 ret = PTR_ERR(dentry);
1846                 goto err;
1847         }
1848
1849         ret = sel_make_avc_files(dentry);
1850         if (ret)
1851                 goto err;
1852
1853         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1854         if (IS_ERR(dentry)) {
1855                 ret = PTR_ERR(dentry);
1856                 goto err;
1857         }
1858
1859         ret = sel_make_initcon_files(dentry);
1860         if (ret)
1861                 goto err;
1862
1863         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1864         if (IS_ERR(class_dir)) {
1865                 ret = PTR_ERR(class_dir);
1866                 class_dir = NULL;
1867                 goto err;
1868         }
1869
1870         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1871         if (IS_ERR(policycap_dir)) {
1872                 ret = PTR_ERR(policycap_dir);
1873                 policycap_dir = NULL;
1874                 goto err;
1875         }
1876         return 0;
1877 err:
1878         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1879                 __func__);
1880         return ret;
1881 }
1882
1883 static struct dentry *sel_mount(struct file_system_type *fs_type,
1884                       int flags, const char *dev_name, void *data)
1885 {
1886         return mount_single(fs_type, flags, data, sel_fill_super);
1887 }
1888
1889 static struct file_system_type sel_fs_type = {
1890         .name           = "selinuxfs",
1891         .mount          = sel_mount,
1892         .kill_sb        = kill_litter_super,
1893 };
1894
1895 struct vfsmount *selinuxfs_mount;
1896 static struct kobject *selinuxfs_kobj;
1897
1898 static int __init init_sel_fs(void)
1899 {
1900         int err;
1901
1902         if (!selinux_enabled)
1903                 return 0;
1904
1905         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1906         if (!selinuxfs_kobj)
1907                 return -ENOMEM;
1908
1909         err = register_filesystem(&sel_fs_type);
1910         if (err) {
1911                 kobject_put(selinuxfs_kobj);
1912                 return err;
1913         }
1914
1915         selinux_null.mnt = 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         kobject_put(selinuxfs_kobj);
1931         kern_unmount(selinuxfs_mount);
1932         unregister_filesystem(&sel_fs_type);
1933 }
1934 #endif