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         "redhat1",
  49         "always_check_network"
  50 };
  51
  52 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  53
  54 static int __init checkreqprot_setup(char *str)
  55 {
  56         unsigned long checkreqprot;
  57         if (!strict_strtoul(str, 0, &checkreqprot))
  58                 selinux_checkreqprot = checkreqprot ? 1 : 0;
  59         return 1;
  60 }
  61 __setup("checkreqprot=", checkreqprot_setup);
  62
  63 static DEFINE_MUTEX(sel_mutex);
  64
  65 /* global data for booleans */
  66 static struct dentry *bool_dir;
  67 static int bool_num;
  68 static char **bool_pending_names;
  69 static int *bool_pending_values;
  70
  71 /* global data for classes */
  72 static struct dentry *class_dir;
  73 static unsigned long last_class_ino;
  74
  75 static char policy_opened;
  76
  77 /* global data for policy capabilities */
  78 static struct dentry *policycap_dir;
  79
  80 /* Check whether a task is allowed to use a security operation. */
  81 static int task_has_security(struct task_struct *tsk,
  82                              u32 perms)
  83 {
  84         const struct task_security_struct *tsec;
  85         u32 sid = 0;
  86
  87         rcu_read_lock();
  88         tsec = __task_cred(tsk)->security;
  89         if (tsec)
  90                 sid = tsec->sid;
  91         rcu_read_unlock();
  92         if (!tsec)
  93                 return -EACCES;
  94
  95         return avc_has_perm(sid, SECINITSID_SECURITY,
  96                             SECCLASS_SECURITY, perms, NULL);
  97 }
  98
  99 enum sel_inos {
 100         SEL_ROOT_INO = 2,
 101         SEL_LOAD,       /* load policy */
 102         SEL_ENFORCE,    /* get or set enforcing status */
 103         SEL_CONTEXT,    /* validate context */
 104         SEL_ACCESS,     /* compute access decision */
 105         SEL_CREATE,     /* compute create labeling decision */
 106         SEL_RELABEL,    /* compute relabeling decision */
 107         SEL_USER,       /* compute reachable user contexts */
 108         SEL_POLICYVERS, /* return policy version for this kernel */
 109         SEL_COMMIT_BOOLS, /* commit new boolean values */
 110         SEL_MLS,        /* return if MLS policy is enabled */
 111         SEL_DISABLE,    /* disable SELinux until next reboot */
 112         SEL_MEMBER,     /* compute polyinstantiation membership decision */
 113         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 114         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 115         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
 116         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 117         SEL_STATUS,     /* export current status using mmap() */
 118         SEL_POLICY,     /* allow userspace to read the in kernel policy */
 119         SEL_INO_NEXT,   /* The next inode number to use */
 120 };
 121
 122 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 123
 124 #define SEL_INITCON_INO_OFFSET          0x01000000
 125 #define SEL_BOOL_INO_OFFSET             0x02000000
 126 #define SEL_CLASS_INO_OFFSET            0x04000000
 127 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
 128 #define SEL_INO_MASK                    0x00ffffff
 129
 130 #define TMPBUFLEN       12
 131 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 132                                 size_t count, loff_t *ppos)
 133 {
 134         char tmpbuf[TMPBUFLEN];
 135         ssize_t length;
 136
 137         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 138         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 139 }
 140
 141 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 142 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 143                                  size_t count, loff_t *ppos)
 144
 145 {
 146         char *page = NULL;
 147         ssize_t length;
 148         int new_value;
 149
 150         length = -ENOMEM;
 151         if (count >= PAGE_SIZE)
 152                 goto out;
 153
 154         /* No partial writes. */
 155         length = EINVAL;
 156         if (*ppos != 0)
 157                 goto out;
 158
 159         length = -ENOMEM;
 160         page = (char *)get_zeroed_page(GFP_KERNEL);
 161         if (!page)
 162                 goto out;
 163
 164         length = -EFAULT;
 165         if (copy_from_user(page, buf, count))
 166                 goto out;
 167
 168         length = -EINVAL;
 169         if (sscanf(page, "%d", &new_value) != 1)
 170                 goto out;
 171
 172         if (new_value != selinux_enforcing) {
 173                 length = task_has_security(current, SECURITY__SETENFORCE);
 174                 if (length)
 175                         goto out;
 176                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 177                         "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 178                         new_value, selinux_enforcing,
 179                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
 180                         audit_get_sessionid(current));
 181                 selinux_enforcing = new_value;
 182                 if (selinux_enforcing)
 183                         avc_ss_reset(0);
 184                 selnl_notify_setenforce(selinux_enforcing);
 185                 selinux_status_update_setenforce(selinux_enforcing);
 186         }
 187         length = count;
 188 out:
 189         free_page((unsigned long) page);
 190         return length;
 191 }
 192 #else
 193 #define sel_write_enforce NULL
 194 #endif
 195
 196 static const struct file_operations sel_enforce_ops = {
 197         .read           = sel_read_enforce,
 198         .write          = sel_write_enforce,
 199         .llseek         = generic_file_llseek,
 200 };
 201
 202 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 203                                         size_t count, loff_t *ppos)
 204 {
 205         char tmpbuf[TMPBUFLEN];
 206         ssize_t length;
 207         ino_t ino = file_inode(filp)->i_ino;
 208         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 209                 security_get_reject_unknown() : !security_get_allow_unknown();
 210
 211         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 212         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 213 }
 214
 215 static const struct file_operations sel_handle_unknown_ops = {
 216         .read           = sel_read_handle_unknown,
 217         .llseek         = generic_file_llseek,
 218 };
 219
 220 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 221 {
 222         struct page    *status = selinux_kernel_status_page();
 223
 224         if (!status)
 225                 return -ENOMEM;
 226
 227         filp->private_data = status;
 228
 229         return 0;
 230 }
 231
 232 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 233                                       size_t count, loff_t *ppos)
 234 {
 235         struct page    *status = filp->private_data;
 236
 237         BUG_ON(!status);
 238
 239         return simple_read_from_buffer(buf, count, ppos,
 240                                        page_address(status),
 241                                        sizeof(struct selinux_kernel_status));
 242 }
 243
 244 static int sel_mmap_handle_status(struct file *filp,
 245                                   struct vm_area_struct *vma)
 246 {
 247         struct page    *status = filp->private_data;
 248         unsigned long   size = vma->vm_end - vma->vm_start;
 249
 250         BUG_ON(!status);
 251
 252         /* only allows one page from the head */
 253         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 254                 return -EIO;
 255         /* disallow writable mapping */
 256         if (vma->vm_flags & VM_WRITE)
 257                 return -EPERM;
 258         /* disallow mprotect() turns it into writable */
 259         vma->vm_flags &= ~VM_MAYWRITE;
 260
 261         return remap_pfn_range(vma, vma->vm_start,
 262                                page_to_pfn(status),
 263                                size, vma->vm_page_prot);
 264 }
 265
 266 static const struct file_operations sel_handle_status_ops = {
 267         .open           = sel_open_handle_status,
 268         .read           = sel_read_handle_status,
 269         .mmap           = sel_mmap_handle_status,
 270         .llseek         = generic_file_llseek,
 271 };
 272
 273 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 274 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 275                                  size_t count, loff_t *ppos)
 276
 277 {
 278         char *page = NULL;
 279         ssize_t length;
 280         int new_value;
 281
 282         length = -ENOMEM;
 283         if (count >= PAGE_SIZE)
 284                 goto out;
 285
 286         /* No partial writes. */
 287         length = -EINVAL;
 288         if (*ppos != 0)
 289                 goto out;
 290
 291         length = -ENOMEM;
 292         page = (char *)get_zeroed_page(GFP_KERNEL);
 293         if (!page)
 294                 goto out;
 295
 296         length = -EFAULT;
 297         if (copy_from_user(page, buf, count))
 298                 goto out;
 299
 300         length = -EINVAL;
 301         if (sscanf(page, "%d", &new_value) != 1)
 302                 goto out;
 303
 304         if (new_value) {
 305                 length = selinux_disable();
 306                 if (length)
 307                         goto out;
 308                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 309                         "selinux=0 auid=%u ses=%u",
 310                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
 311                         audit_get_sessionid(current));
 312         }
 313
 314         length = count;
 315 out:
 316         free_page((unsigned long) page);
 317         return length;
 318 }
 319 #else
 320 #define sel_write_disable NULL
 321 #endif
 322
 323 static const struct file_operations sel_disable_ops = {
 324         .write          = sel_write_disable,
 325         .llseek         = generic_file_llseek,
 326 };
 327
 328 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 329                                    size_t count, loff_t *ppos)
 330 {
 331         char tmpbuf[TMPBUFLEN];
 332         ssize_t length;
 333
 334         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 335         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 336 }
 337
 338 static const struct file_operations sel_policyvers_ops = {
 339         .read           = sel_read_policyvers,
 340         .llseek         = generic_file_llseek,
 341 };
 342
 343 /* declaration for sel_write_load */
 344 static int sel_make_bools(void);
 345 static int sel_make_classes(void);
 346 static int sel_make_policycap(void);
 347
 348 /* declaration for sel_make_class_dirs */
 349 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 350                         unsigned long *ino);
 351
 352 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 353                                 size_t count, loff_t *ppos)
 354 {
 355         char tmpbuf[TMPBUFLEN];
 356         ssize_t length;
 357
 358         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 359                            security_mls_enabled());
 360         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 361 }
 362
 363 static const struct file_operations sel_mls_ops = {
 364         .read           = sel_read_mls,
 365         .llseek         = generic_file_llseek,
 366 };
 367
 368 struct policy_load_memory {
 369         size_t len;
 370         void *data;
 371 };
 372
 373 static int sel_open_policy(struct inode *inode, struct file *filp)
 374 {
 375         struct policy_load_memory *plm = NULL;
 376         int rc;
 377
 378         BUG_ON(filp->private_data);
 379
 380         mutex_lock(&sel_mutex);
 381
 382         rc = task_has_security(current, SECURITY__READ_POLICY);
 383         if (rc)
 384                 goto err;
 385
 386         rc = -EBUSY;
 387         if (policy_opened)
 388                 goto err;
 389
 390         rc = -ENOMEM;
 391         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 392         if (!plm)
 393                 goto err;
 394
 395         if (i_size_read(inode) != security_policydb_len()) {
 396                 mutex_lock(&inode->i_mutex);
 397                 i_size_write(inode, security_policydb_len());
 398                 mutex_unlock(&inode->i_mutex);
 399         }
 400
 401         rc = security_read_policy(&plm->data, &plm->len);
 402         if (rc)
 403                 goto err;
 404
 405         policy_opened = 1;
 406
 407         filp->private_data = plm;
 408
 409         mutex_unlock(&sel_mutex);
 410
 411         return 0;
 412 err:
 413         mutex_unlock(&sel_mutex);
 414
 415         if (plm)
 416                 vfree(plm->data);
 417         kfree(plm);
 418         return rc;
 419 }
 420
 421 static int sel_release_policy(struct inode *inode, struct file *filp)
 422 {
 423         struct policy_load_memory *plm = filp->private_data;
 424
 425         BUG_ON(!plm);
 426
 427         policy_opened = 0;
 428
 429         vfree(plm->data);
 430         kfree(plm);
 431
 432         return 0;
 433 }
 434
 435 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 436                                size_t count, loff_t *ppos)
 437 {
 438         struct policy_load_memory *plm = filp->private_data;
 439         int ret;
 440
 441         mutex_lock(&sel_mutex);
 442
 443         ret = task_has_security(current, SECURITY__READ_POLICY);
 444         if (ret)
 445                 goto out;
 446
 447         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 448 out:
 449         mutex_unlock(&sel_mutex);
 450         return ret;
 451 }
 452
 453 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 454                                  struct vm_fault *vmf)
 455 {
 456         struct policy_load_memory *plm = vma->vm_file->private_data;
 457         unsigned long offset;
 458         struct page *page;
 459
 460         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 461                 return VM_FAULT_SIGBUS;
 462
 463         offset = vmf->pgoff << PAGE_SHIFT;
 464         if (offset >= roundup(plm->len, PAGE_SIZE))
 465                 return VM_FAULT_SIGBUS;
 466
 467         page = vmalloc_to_page(plm->data + offset);
 468         get_page(page);
 469
 470         vmf->page = page;
 471
 472         return 0;
 473 }
 474
 475 static struct vm_operations_struct sel_mmap_policy_ops = {
 476         .fault = sel_mmap_policy_fault,
 477         .page_mkwrite = sel_mmap_policy_fault,
 478 };
 479
 480 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 481 {
 482         if (vma->vm_flags & VM_SHARED) {
 483                 /* do not allow mprotect to make mapping writable */
 484                 vma->vm_flags &= ~VM_MAYWRITE;
 485
 486                 if (vma->vm_flags & VM_WRITE)
 487                         return -EACCES;
 488         }
 489
 490         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 491         vma->vm_ops = &sel_mmap_policy_ops;
 492
 493         return 0;
 494 }
 495
 496 static const struct file_operations sel_policy_ops = {
 497         .open           = sel_open_policy,
 498         .read           = sel_read_policy,
 499         .mmap           = sel_mmap_policy,
 500         .release        = sel_release_policy,
 501         .llseek         = generic_file_llseek,
 502 };
 503
 504 static ssize_t sel_write_load(struct file *file, const char __user *buf,
 505                               size_t count, loff_t *ppos)
 506
 507 {
 508         ssize_t length;
 509         void *data = NULL;
 510
 511         mutex_lock(&sel_mutex);
 512
 513         length = task_has_security(current, SECURITY__LOAD_POLICY);
 514         if (length)
 515                 goto out;
 516
 517         /* No partial writes. */
 518         length = -EINVAL;
 519         if (*ppos != 0)
 520                 goto out;
 521
 522         length = -EFBIG;
 523         if (count > 64 * 1024 * 1024)
 524                 goto out;
 525
 526         length = -ENOMEM;
 527         data = vmalloc(count);
 528         if (!data)
 529                 goto out;
 530
 531         length = -EFAULT;
 532         if (copy_from_user(data, buf, count) != 0)
 533                 goto out;
 534
 535         length = security_load_policy(data, count);
 536         if (length)
 537                 goto out;
 538
 539         length = sel_make_bools();
 540         if (length)
 541                 goto out1;
 542
 543         length = sel_make_classes();
 544         if (length)
 545                 goto out1;
 546
 547         length = sel_make_policycap();
 548         if (length)
 549                 goto out1;
 550
 551         length = count;
 552
 553 out1:
 554         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 555                 "policy loaded auid=%u ses=%u",
 556                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
 557                 audit_get_sessionid(current));
 558 out:
 559         mutex_unlock(&sel_mutex);
 560         vfree(data);
 561         return length;
 562 }
 563
 564 static const struct file_operations sel_load_ops = {
 565         .write          = sel_write_load,
 566         .llseek         = generic_file_llseek,
 567 };
 568
 569 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 570 {
 571         char *canon = NULL;
 572         u32 sid, len;
 573         ssize_t length;
 574
 575         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 576         if (length)
 577                 goto out;
 578
 579         length = security_context_to_sid(buf, size, &sid);
 580         if (length)
 581                 goto out;
 582
 583         length = security_sid_to_context(sid, &canon, &len);
 584         if (length)
 585                 goto out;
 586
 587         length = -ERANGE;
 588         if (len > SIMPLE_TRANSACTION_LIMIT) {
 589                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 590                         "payload max\n", __func__, len);
 591                 goto out;
 592         }
 593
 594         memcpy(buf, canon, len);
 595         length = len;
 596 out:
 597         kfree(canon);
 598         return length;
 599 }
 600
 601 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 602                                      size_t count, loff_t *ppos)
 603 {
 604         char tmpbuf[TMPBUFLEN];
 605         ssize_t length;
 606
 607         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 608         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 609 }
 610
 611 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 612                                       size_t count, loff_t *ppos)
 613 {
 614         char *page = NULL;
 615         ssize_t length;
 616         unsigned int new_value;
 617
 618         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 619         if (length)
 620                 goto out;
 621
 622         length = -ENOMEM;
 623         if (count >= PAGE_SIZE)
 624                 goto out;
 625
 626         /* No partial writes. */
 627         length = -EINVAL;
 628         if (*ppos != 0)
 629                 goto out;
 630
 631         length = -ENOMEM;
 632         page = (char *)get_zeroed_page(GFP_KERNEL);
 633         if (!page)
 634                 goto out;
 635
 636         length = -EFAULT;
 637         if (copy_from_user(page, buf, count))
 638                 goto out;
 639
 640         length = -EINVAL;
 641         if (sscanf(page, "%u", &new_value) != 1)
 642                 goto out;
 643
 644         selinux_checkreqprot = new_value ? 1 : 0;
 645         length = count;
 646 out:
 647         free_page((unsigned long) page);
 648         return length;
 649 }
 650 static const struct file_operations sel_checkreqprot_ops = {
 651         .read           = sel_read_checkreqprot,
 652         .write          = sel_write_checkreqprot,
 653         .llseek         = generic_file_llseek,
 654 };
 655
 656 /*
 657  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 658  */
 659 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 660 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 661 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 662 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 663 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 664
 665 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 666         [SEL_ACCESS] = sel_write_access,
 667         [SEL_CREATE] = sel_write_create,
 668         [SEL_RELABEL] = sel_write_relabel,
 669         [SEL_USER] = sel_write_user,
 670         [SEL_MEMBER] = sel_write_member,
 671         [SEL_CONTEXT] = sel_write_context,
 672 };
 673
 674 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 675 {
 676         ino_t ino = file_inode(file)->i_ino;
 677         char *data;
 678         ssize_t rv;
 679
 680         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 681                 return -EINVAL;
 682
 683         data = simple_transaction_get(file, buf, size);
 684         if (IS_ERR(data))
 685                 return PTR_ERR(data);
 686
 687         rv = write_op[ino](file, data, size);
 688         if (rv > 0) {
 689                 simple_transaction_set(file, rv);
 690                 rv = size;
 691         }
 692         return rv;
 693 }
 694
 695 static const struct file_operations transaction_ops = {
 696         .write          = selinux_transaction_write,
 697         .read           = simple_transaction_read,
 698         .release        = simple_transaction_release,
 699         .llseek         = generic_file_llseek,
 700 };
 701
 702 /*
 703  * payload - write methods
 704  * If the method has a response, the response should be put in buf,
 705  * and the length returned.  Otherwise return 0 or and -error.
 706  */
 707
 708 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 709 {
 710         char *scon = NULL, *tcon = NULL;
 711         u32 ssid, tsid;
 712         u16 tclass;
 713         struct av_decision avd;
 714         ssize_t length;
 715
 716         length = task_has_security(current, SECURITY__COMPUTE_AV);
 717         if (length)
 718                 goto out;
 719
 720         length = -ENOMEM;
 721         scon = kzalloc(size + 1, GFP_KERNEL);
 722         if (!scon)
 723                 goto out;
 724
 725         length = -ENOMEM;
 726         tcon = kzalloc(size + 1, GFP_KERNEL);
 727         if (!tcon)
 728                 goto out;
 729
 730         length = -EINVAL;
 731         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 732                 goto out;
 733
 734         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 735         if (length)
 736                 goto out;
 737
 738         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 739         if (length)
 740                 goto out;
 741
 742         security_compute_av_user(ssid, tsid, tclass, &avd);
 743
 744         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 745                           "%x %x %x %x %u %x",
 746                           avd.allowed, 0xffffffff,
 747                           avd.auditallow, avd.auditdeny,
 748                           avd.seqno, avd.flags);
 749 out:
 750         kfree(tcon);
 751         kfree(scon);
 752         return length;
 753 }
 754
 755 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 756 {
 757         char *scon = NULL, *tcon = NULL;
 758         char *namebuf = NULL, *objname = NULL;
 759         u32 ssid, tsid, newsid;
 760         u16 tclass;
 761         ssize_t length;
 762         char *newcon = NULL;
 763         u32 len;
 764         int nargs;
 765
 766         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 767         if (length)
 768                 goto out;
 769
 770         length = -ENOMEM;
 771         scon = kzalloc(size + 1, GFP_KERNEL);
 772         if (!scon)
 773                 goto out;
 774
 775         length = -ENOMEM;
 776         tcon = kzalloc(size + 1, GFP_KERNEL);
 777         if (!tcon)
 778                 goto out;
 779
 780         length = -ENOMEM;
 781         namebuf = kzalloc(size + 1, GFP_KERNEL);
 782         if (!namebuf)
 783                 goto out;
 784
 785         length = -EINVAL;
 786         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 787         if (nargs < 3 || nargs > 4)
 788                 goto out;
 789         if (nargs == 4) {
 790                 /*
 791                  * If and when the name of new object to be queried contains
 792                  * either whitespace or multibyte characters, they shall be
 793                  * encoded based on the percentage-encoding rule.
 794                  * If not encoded, the sscanf logic picks up only left-half
 795                  * of the supplied name; splitted by a whitespace unexpectedly.
 796                  */
 797                 char   *r, *w;
 798                 int     c1, c2;
 799
 800                 r = w = namebuf;
 801                 do {
 802                         c1 = *r++;
 803                         if (c1 == '+')
 804                                 c1 = ' ';
 805                         else if (c1 == '%') {
 806                                 c1 = hex_to_bin(*r++);
 807                                 if (c1 < 0)
 808                                         goto out;
 809                                 c2 = hex_to_bin(*r++);
 810                                 if (c2 < 0)
 811                                         goto out;
 812                                 c1 = (c1 << 4) | c2;
 813                         }
 814                         *w++ = c1;
 815                 } while (c1 != '\0');
 816
 817                 objname = namebuf;
 818         }
 819
 820         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 821         if (length)
 822                 goto out;
 823
 824         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 825         if (length)
 826                 goto out;
 827
 828         length = security_transition_sid_user(ssid, tsid, tclass,
 829                                               objname, &newsid);
 830         if (length)
 831                 goto out;
 832
 833         length = security_sid_to_context(newsid, &newcon, &len);
 834         if (length)
 835                 goto out;
 836
 837         length = -ERANGE;
 838         if (len > SIMPLE_TRANSACTION_LIMIT) {
 839                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 840                         "payload max\n", __func__, len);
 841                 goto out;
 842         }
 843
 844         memcpy(buf, newcon, len);
 845         length = len;
 846 out:
 847         kfree(newcon);
 848         kfree(namebuf);
 849         kfree(tcon);
 850         kfree(scon);
 851         return length;
 852 }
 853
 854 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 855 {
 856         char *scon = NULL, *tcon = NULL;
 857         u32 ssid, tsid, newsid;
 858         u16 tclass;
 859         ssize_t length;
 860         char *newcon = NULL;
 861         u32 len;
 862
 863         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 864         if (length)
 865                 goto out;
 866
 867         length = -ENOMEM;
 868         scon = kzalloc(size + 1, GFP_KERNEL);
 869         if (!scon)
 870                 goto out;
 871
 872         length = -ENOMEM;
 873         tcon = kzalloc(size + 1, GFP_KERNEL);
 874         if (!tcon)
 875                 goto out;
 876
 877         length = -EINVAL;
 878         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 879                 goto out;
 880
 881         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 882         if (length)
 883                 goto out;
 884
 885         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 886         if (length)
 887                 goto out;
 888
 889         length = security_change_sid(ssid, tsid, tclass, &newsid);
 890         if (length)
 891                 goto out;
 892
 893         length = security_sid_to_context(newsid, &newcon, &len);
 894         if (length)
 895                 goto out;
 896
 897         length = -ERANGE;
 898         if (len > SIMPLE_TRANSACTION_LIMIT)
 899                 goto out;
 900
 901         memcpy(buf, newcon, len);
 902         length = len;
 903 out:
 904         kfree(newcon);
 905         kfree(tcon);
 906         kfree(scon);
 907         return length;
 908 }
 909
 910 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 911 {
 912         char *con = NULL, *user = NULL, *ptr;
 913         u32 sid, *sids = NULL;
 914         ssize_t length;
 915         char *newcon;
 916         int i, rc;
 917         u32 len, nsids;
 918
 919         length = task_has_security(current, SECURITY__COMPUTE_USER);
 920         if (length)
 921                 goto out;
 922
 923         length = -ENOMEM;
 924         con = kzalloc(size + 1, GFP_KERNEL);
 925         if (!con)
 926                 goto out;
 927
 928         length = -ENOMEM;
 929         user = kzalloc(size + 1, GFP_KERNEL);
 930         if (!user)
 931                 goto out;
 932
 933         length = -EINVAL;
 934         if (sscanf(buf, "%s %s", con, user) != 2)
 935                 goto out;
 936
 937         length = security_context_to_sid(con, strlen(con) + 1, &sid);
 938         if (length)
 939                 goto out;
 940
 941         length = security_get_user_sids(sid, user, &sids, &nsids);
 942         if (length)
 943                 goto out;
 944
 945         length = sprintf(buf, "%u", nsids) + 1;
 946         ptr = buf + length;
 947         for (i = 0; i < nsids; i++) {
 948                 rc = security_sid_to_context(sids[i], &newcon, &len);
 949                 if (rc) {
 950                         length = rc;
 951                         goto out;
 952                 }
 953                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 954                         kfree(newcon);
 955                         length = -ERANGE;
 956                         goto out;
 957                 }
 958                 memcpy(ptr, newcon, len);
 959                 kfree(newcon);
 960                 ptr += len;
 961                 length += len;
 962         }
 963 out:
 964         kfree(sids);
 965         kfree(user);
 966         kfree(con);
 967         return length;
 968 }
 969
 970 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 971 {
 972         char *scon = NULL, *tcon = NULL;
 973         u32 ssid, tsid, newsid;
 974         u16 tclass;
 975         ssize_t length;
 976         char *newcon = NULL;
 977         u32 len;
 978
 979         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 980         if (length)
 981                 goto out;
 982
 983         length = -ENOMEM;
 984         scon = kzalloc(size + 1, GFP_KERNEL);
 985         if (!scon)
 986                 goto out;
 987
 988         length = -ENOMEM;
 989         tcon = kzalloc(size + 1, GFP_KERNEL);
 990         if (!tcon)
 991                 goto out;
 992
 993         length = -EINVAL;
 994         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 995                 goto out;
 996
 997         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 998         if (length)
 999                 goto out;
1000
1001         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1002         if (length)
1003                 goto out;
1004
1005         length = security_member_sid(ssid, tsid, tclass, &newsid);
1006         if (length)
1007                 goto out;
1008
1009         length = security_sid_to_context(newsid, &newcon, &len);
1010         if (length)
1011                 goto out;
1012
1013         length = -ERANGE;
1014         if (len > SIMPLE_TRANSACTION_LIMIT) {
1015                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1016                         "payload max\n", __func__, len);
1017                 goto out;
1018         }
1019
1020         memcpy(buf, newcon, len);
1021         length = len;
1022 out:
1023         kfree(newcon);
1024         kfree(tcon);
1025         kfree(scon);
1026         return length;
1027 }
1028
1029 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1030 {
1031         struct inode *ret = new_inode(sb);
1032
1033         if (ret) {
1034                 ret->i_mode = mode;
1035                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1036         }
1037         return ret;
1038 }
1039
1040 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1041                              size_t count, loff_t *ppos)
1042 {
1043         char *page = NULL;
1044         ssize_t length;
1045         ssize_t ret;
1046         int cur_enforcing;
1047         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1048         const char *name = filep->f_path.dentry->d_name.name;
1049
1050         mutex_lock(&sel_mutex);
1051
1052         ret = -EINVAL;
1053         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1054                 goto out;
1055
1056         ret = -ENOMEM;
1057         page = (char *)get_zeroed_page(GFP_KERNEL);
1058         if (!page)
1059                 goto out;
1060
1061         cur_enforcing = security_get_bool_value(index);
1062         if (cur_enforcing < 0) {
1063                 ret = cur_enforcing;
1064                 goto out;
1065         }
1066         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1067                           bool_pending_values[index]);
1068         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1069 out:
1070         mutex_unlock(&sel_mutex);
1071         free_page((unsigned long)page);
1072         return ret;
1073 }
1074
1075 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1076                               size_t count, loff_t *ppos)
1077 {
1078         char *page = NULL;
1079         ssize_t length;
1080         int new_value;
1081         unsigned index = file_inode(filep)->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         char *con;
1490         u32 sid, len;
1491         ssize_t ret;
1492
1493         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1494         ret = security_sid_to_context(sid, &con, &len);
1495         if (ret)
1496                 return ret;
1497
1498         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1499         kfree(con);
1500         return ret;
1501 }
1502
1503 static const struct file_operations sel_initcon_ops = {
1504         .read           = sel_read_initcon,
1505         .llseek         = generic_file_llseek,
1506 };
1507
1508 static int sel_make_initcon_files(struct dentry *dir)
1509 {
1510         int i;
1511
1512         for (i = 1; i <= SECINITSID_NUM; i++) {
1513                 struct inode *inode;
1514                 struct dentry *dentry;
1515                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1516                 if (!dentry)
1517                         return -ENOMEM;
1518
1519                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1520                 if (!inode)
1521                         return -ENOMEM;
1522
1523                 inode->i_fop = &sel_initcon_ops;
1524                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1525                 d_add(dentry, inode);
1526         }
1527
1528         return 0;
1529 }
1530
1531 static inline unsigned long sel_class_to_ino(u16 class)
1532 {
1533         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1534 }
1535
1536 static inline u16 sel_ino_to_class(unsigned long ino)
1537 {
1538         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1539 }
1540
1541 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1542 {
1543         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1544 }
1545
1546 static inline u32 sel_ino_to_perm(unsigned long ino)
1547 {
1548         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1549 }
1550
1551 static ssize_t sel_read_class(struct file *file, char __user *buf,
1552                                 size_t count, loff_t *ppos)
1553 {
1554         unsigned long ino = file_inode(file)->i_ino;
1555         char res[TMPBUFLEN];
1556         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1557         return simple_read_from_buffer(buf, count, ppos, res, len);
1558 }
1559
1560 static const struct file_operations sel_class_ops = {
1561         .read           = sel_read_class,
1562         .llseek         = generic_file_llseek,
1563 };
1564
1565 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1566                                 size_t count, loff_t *ppos)
1567 {
1568         unsigned long ino = file_inode(file)->i_ino;
1569         char res[TMPBUFLEN];
1570         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1571         return simple_read_from_buffer(buf, count, ppos, res, len);
1572 }
1573
1574 static const struct file_operations sel_perm_ops = {
1575         .read           = sel_read_perm,
1576         .llseek         = generic_file_llseek,
1577 };
1578
1579 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1580                                   size_t count, loff_t *ppos)
1581 {
1582         int value;
1583         char tmpbuf[TMPBUFLEN];
1584         ssize_t length;
1585         unsigned long i_ino = file_inode(file)->i_ino;
1586
1587         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1588         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1589
1590         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1591 }
1592
1593 static const struct file_operations sel_policycap_ops = {
1594         .read           = sel_read_policycap,
1595         .llseek         = generic_file_llseek,
1596 };
1597
1598 static int sel_make_perm_files(char *objclass, int classvalue,
1599                                 struct dentry *dir)
1600 {
1601         int i, rc, nperms;
1602         char **perms;
1603
1604         rc = security_get_permissions(objclass, &perms, &nperms);
1605         if (rc)
1606                 return rc;
1607
1608         for (i = 0; i < nperms; i++) {
1609                 struct inode *inode;
1610                 struct dentry *dentry;
1611
1612                 rc = -ENOMEM;
1613                 dentry = d_alloc_name(dir, perms[i]);
1614                 if (!dentry)
1615                         goto out;
1616
1617                 rc = -ENOMEM;
1618                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1619                 if (!inode)
1620                         goto out;
1621
1622                 inode->i_fop = &sel_perm_ops;
1623                 /* i+1 since perm values are 1-indexed */
1624                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1625                 d_add(dentry, inode);
1626         }
1627         rc = 0;
1628 out:
1629         for (i = 0; i < nperms; i++)
1630                 kfree(perms[i]);
1631         kfree(perms);
1632         return rc;
1633 }
1634
1635 static int sel_make_class_dir_entries(char *classname, int index,
1636                                         struct dentry *dir)
1637 {
1638         struct dentry *dentry = NULL;
1639         struct inode *inode = NULL;
1640         int rc;
1641
1642         dentry = d_alloc_name(dir, "index");
1643         if (!dentry)
1644                 return -ENOMEM;
1645
1646         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1647         if (!inode)
1648                 return -ENOMEM;
1649
1650         inode->i_fop = &sel_class_ops;
1651         inode->i_ino = sel_class_to_ino(index);
1652         d_add(dentry, inode);
1653
1654         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1655         if (IS_ERR(dentry))
1656                 return PTR_ERR(dentry);
1657
1658         rc = sel_make_perm_files(classname, index, dentry);
1659
1660         return rc;
1661 }
1662
1663 static void sel_remove_classes(void)
1664 {
1665         struct list_head *class_node;
1666
1667         list_for_each(class_node, &class_dir->d_subdirs) {
1668                 struct dentry *class_subdir = list_entry(class_node,
1669                                         struct dentry, d_u.d_child);
1670                 struct list_head *class_subdir_node;
1671
1672                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1673                         struct dentry *d = list_entry(class_subdir_node,
1674                                                 struct dentry, d_u.d_child);
1675
1676                         if (d->d_inode)
1677                                 if (d->d_inode->i_mode & S_IFDIR)
1678                                         sel_remove_entries(d);
1679                 }
1680
1681                 sel_remove_entries(class_subdir);
1682         }
1683
1684         sel_remove_entries(class_dir);
1685 }
1686
1687 static int sel_make_classes(void)
1688 {
1689         int rc, nclasses, i;
1690         char **classes;
1691
1692         /* delete any existing entries */
1693         sel_remove_classes();
1694
1695         rc = security_get_classes(&classes, &nclasses);
1696         if (rc)
1697                 return rc;
1698
1699         /* +2 since classes are 1-indexed */
1700         last_class_ino = sel_class_to_ino(nclasses + 2);
1701
1702         for (i = 0; i < nclasses; i++) {
1703                 struct dentry *class_name_dir;
1704
1705                 class_name_dir = sel_make_dir(class_dir, classes[i],
1706                                 &last_class_ino);
1707                 if (IS_ERR(class_name_dir)) {
1708                         rc = PTR_ERR(class_name_dir);
1709                         goto out;
1710                 }
1711
1712                 /* i+1 since class values are 1-indexed */
1713                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1714                                 class_name_dir);
1715                 if (rc)
1716                         goto out;
1717         }
1718         rc = 0;
1719 out:
1720         for (i = 0; i < nclasses; i++)
1721                 kfree(classes[i]);
1722         kfree(classes);
1723         return rc;
1724 }
1725
1726 static int sel_make_policycap(void)
1727 {
1728         unsigned int iter;
1729         struct dentry *dentry = NULL;
1730         struct inode *inode = NULL;
1731
1732         sel_remove_entries(policycap_dir);
1733
1734         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1735                 if (iter < ARRAY_SIZE(policycap_names))
1736                         dentry = d_alloc_name(policycap_dir,
1737                                               policycap_names[iter]);
1738                 else
1739                         dentry = d_alloc_name(policycap_dir, "unknown");
1740
1741                 if (dentry == NULL)
1742                         return -ENOMEM;
1743
1744                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1745                 if (inode == NULL)
1746                         return -ENOMEM;
1747
1748                 inode->i_fop = &sel_policycap_ops;
1749                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1750                 d_add(dentry, inode);
1751         }
1752
1753         return 0;
1754 }
1755
1756 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1757                         unsigned long *ino)
1758 {
1759         struct dentry *dentry = d_alloc_name(dir, name);
1760         struct inode *inode;
1761
1762         if (!dentry)
1763                 return ERR_PTR(-ENOMEM);
1764
1765         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1766         if (!inode) {
1767                 dput(dentry);
1768                 return ERR_PTR(-ENOMEM);
1769         }
1770
1771         inode->i_op = &simple_dir_inode_operations;
1772         inode->i_fop = &simple_dir_operations;
1773         inode->i_ino = ++(*ino);
1774         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1775         inc_nlink(inode);
1776         d_add(dentry, inode);
1777         /* bump link count on parent directory, too */
1778         inc_nlink(dir->d_inode);
1779
1780         return dentry;
1781 }
1782
1783 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1784 {
1785         int ret;
1786         struct dentry *dentry;
1787         struct inode *inode;
1788         struct inode_security_struct *isec;
1789
1790         static struct tree_descr selinux_files[] = {
1791                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1792                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1793                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1794                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1795                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1796                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1797                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1798                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1799                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1800                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1801                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1802                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1803                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1804                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1805                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1806                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1807                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1808                 /* last one */ {""}
1809         };
1810         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1811         if (ret)
1812                 goto err;
1813
1814         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1815         if (IS_ERR(bool_dir)) {
1816                 ret = PTR_ERR(bool_dir);
1817                 bool_dir = NULL;
1818                 goto err;
1819         }
1820
1821         ret = -ENOMEM;
1822         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1823         if (!dentry)
1824                 goto err;
1825
1826         ret = -ENOMEM;
1827         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1828         if (!inode)
1829                 goto err;
1830
1831         inode->i_ino = ++sel_last_ino;
1832         isec = (struct inode_security_struct *)inode->i_security;
1833         isec->sid = SECINITSID_DEVNULL;
1834         isec->sclass = SECCLASS_CHR_FILE;
1835         isec->initialized = 1;
1836
1837         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1838         d_add(dentry, inode);
1839         selinux_null.dentry = dentry;
1840
1841         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1842         if (IS_ERR(dentry)) {
1843                 ret = PTR_ERR(dentry);
1844                 goto err;
1845         }
1846
1847         ret = sel_make_avc_files(dentry);
1848         if (ret)
1849                 goto err;
1850
1851         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1852         if (IS_ERR(dentry)) {
1853                 ret = PTR_ERR(dentry);
1854                 goto err;
1855         }
1856
1857         ret = sel_make_initcon_files(dentry);
1858         if (ret)
1859                 goto err;
1860
1861         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1862         if (IS_ERR(class_dir)) {
1863                 ret = PTR_ERR(class_dir);
1864                 class_dir = NULL;
1865                 goto err;
1866         }
1867
1868         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1869         if (IS_ERR(policycap_dir)) {
1870                 ret = PTR_ERR(policycap_dir);
1871                 policycap_dir = NULL;
1872                 goto err;
1873         }
1874         return 0;
1875 err:
1876         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1877                 __func__);
1878         return ret;
1879 }
1880
1881 static struct dentry *sel_mount(struct file_system_type *fs_type,
1882                       int flags, const char *dev_name, void *data)
1883 {
1884         return mount_single(fs_type, flags, data, sel_fill_super);
1885 }
1886
1887 static struct file_system_type sel_fs_type = {
1888         .name           = "selinuxfs",
1889         .mount          = sel_mount,
1890         .kill_sb        = kill_litter_super,
1891 };
1892
1893 struct vfsmount *selinuxfs_mount;
1894 static struct kobject *selinuxfs_kobj;
1895
1896 static int __init init_sel_fs(void)
1897 {
1898         int err;
1899
1900         if (!selinux_enabled)
1901                 return 0;
1902
1903         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1904         if (!selinuxfs_kobj)
1905                 return -ENOMEM;
1906
1907         err = register_filesystem(&sel_fs_type);
1908         if (err) {
1909                 kobject_put(selinuxfs_kobj);
1910                 return err;
1911         }
1912
1913         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1914         if (IS_ERR(selinuxfs_mount)) {
1915                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1916                 err = PTR_ERR(selinuxfs_mount);
1917                 selinuxfs_mount = NULL;
1918         }
1919
1920         return err;
1921 }
1922
1923 __initcall(init_sel_fs);
1924
1925 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1926 void exit_sel_fs(void)
1927 {
1928         kobject_put(selinuxfs_kobj);
1929         kern_unmount(selinuxfs_mount);
1930         unregister_filesystem(&sel_fs_type);
1931 }
1932 #endif