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 (!kstrtoul(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, GFP_KERNEL);
 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                                          GFP_KERNEL);
 736         if (length)
 737                 goto out;
 738
 739         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
 740                                          GFP_KERNEL);
 741         if (length)
 742                 goto out;
 743
 744         security_compute_av_user(ssid, tsid, tclass, &avd);
 745
 746         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 747                           "%x %x %x %x %u %x",
 748                           avd.allowed, 0xffffffff,
 749                           avd.auditallow, avd.auditdeny,
 750                           avd.seqno, avd.flags);
 751 out:
 752         kfree(tcon);
 753         kfree(scon);
 754         return length;
 755 }
 756
 757 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 758 {
 759         char *scon = NULL, *tcon = NULL;
 760         char *namebuf = NULL, *objname = NULL;
 761         u32 ssid, tsid, newsid;
 762         u16 tclass;
 763         ssize_t length;
 764         char *newcon = NULL;
 765         u32 len;
 766         int nargs;
 767
 768         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 769         if (length)
 770                 goto out;
 771
 772         length = -ENOMEM;
 773         scon = kzalloc(size + 1, GFP_KERNEL);
 774         if (!scon)
 775                 goto out;
 776
 777         length = -ENOMEM;
 778         tcon = kzalloc(size + 1, GFP_KERNEL);
 779         if (!tcon)
 780                 goto out;
 781
 782         length = -ENOMEM;
 783         namebuf = kzalloc(size + 1, GFP_KERNEL);
 784         if (!namebuf)
 785                 goto out;
 786
 787         length = -EINVAL;
 788         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 789         if (nargs < 3 || nargs > 4)
 790                 goto out;
 791         if (nargs == 4) {
 792                 /*
 793                  * If and when the name of new object to be queried contains
 794                  * either whitespace or multibyte characters, they shall be
 795                  * encoded based on the percentage-encoding rule.
 796                  * If not encoded, the sscanf logic picks up only left-half
 797                  * of the supplied name; splitted by a whitespace unexpectedly.
 798                  */
 799                 char   *r, *w;
 800                 int     c1, c2;
 801
 802                 r = w = namebuf;
 803                 do {
 804                         c1 = *r++;
 805                         if (c1 == '+')
 806                                 c1 = ' ';
 807                         else if (c1 == '%') {
 808                                 c1 = hex_to_bin(*r++);
 809                                 if (c1 < 0)
 810                                         goto out;
 811                                 c2 = hex_to_bin(*r++);
 812                                 if (c2 < 0)
 813                                         goto out;
 814                                 c1 = (c1 << 4) | c2;
 815                         }
 816                         *w++ = c1;
 817                 } while (c1 != '\0');
 818
 819                 objname = namebuf;
 820         }
 821
 822         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
 823                                          GFP_KERNEL);
 824         if (length)
 825                 goto out;
 826
 827         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
 828                                          GFP_KERNEL);
 829         if (length)
 830                 goto out;
 831
 832         length = security_transition_sid_user(ssid, tsid, tclass,
 833                                               objname, &newsid);
 834         if (length)
 835                 goto out;
 836
 837         length = security_sid_to_context(newsid, &newcon, &len);
 838         if (length)
 839                 goto out;
 840
 841         length = -ERANGE;
 842         if (len > SIMPLE_TRANSACTION_LIMIT) {
 843                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 844                         "payload max\n", __func__, len);
 845                 goto out;
 846         }
 847
 848         memcpy(buf, newcon, len);
 849         length = len;
 850 out:
 851         kfree(newcon);
 852         kfree(namebuf);
 853         kfree(tcon);
 854         kfree(scon);
 855         return length;
 856 }
 857
 858 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 859 {
 860         char *scon = NULL, *tcon = NULL;
 861         u32 ssid, tsid, newsid;
 862         u16 tclass;
 863         ssize_t length;
 864         char *newcon = NULL;
 865         u32 len;
 866
 867         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 868         if (length)
 869                 goto out;
 870
 871         length = -ENOMEM;
 872         scon = kzalloc(size + 1, GFP_KERNEL);
 873         if (!scon)
 874                 goto out;
 875
 876         length = -ENOMEM;
 877         tcon = kzalloc(size + 1, GFP_KERNEL);
 878         if (!tcon)
 879                 goto out;
 880
 881         length = -EINVAL;
 882         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 883                 goto out;
 884
 885         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
 886                                          GFP_KERNEL);
 887         if (length)
 888                 goto out;
 889
 890         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
 891                                          GFP_KERNEL);
 892         if (length)
 893                 goto out;
 894
 895         length = security_change_sid(ssid, tsid, tclass, &newsid);
 896         if (length)
 897                 goto out;
 898
 899         length = security_sid_to_context(newsid, &newcon, &len);
 900         if (length)
 901                 goto out;
 902
 903         length = -ERANGE;
 904         if (len > SIMPLE_TRANSACTION_LIMIT)
 905                 goto out;
 906
 907         memcpy(buf, newcon, len);
 908         length = len;
 909 out:
 910         kfree(newcon);
 911         kfree(tcon);
 912         kfree(scon);
 913         return length;
 914 }
 915
 916 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 917 {
 918         char *con = NULL, *user = NULL, *ptr;
 919         u32 sid, *sids = NULL;
 920         ssize_t length;
 921         char *newcon;
 922         int i, rc;
 923         u32 len, nsids;
 924
 925         length = task_has_security(current, SECURITY__COMPUTE_USER);
 926         if (length)
 927                 goto out;
 928
 929         length = -ENOMEM;
 930         con = kzalloc(size + 1, GFP_KERNEL);
 931         if (!con)
 932                 goto out;
 933
 934         length = -ENOMEM;
 935         user = kzalloc(size + 1, GFP_KERNEL);
 936         if (!user)
 937                 goto out;
 938
 939         length = -EINVAL;
 940         if (sscanf(buf, "%s %s", con, user) != 2)
 941                 goto out;
 942
 943         length = security_context_to_sid(con, strlen(con) + 1, &sid, GFP_KERNEL);
 944         if (length)
 945                 goto out;
 946
 947         length = security_get_user_sids(sid, user, &sids, &nsids);
 948         if (length)
 949                 goto out;
 950
 951         length = sprintf(buf, "%u", nsids) + 1;
 952         ptr = buf + length;
 953         for (i = 0; i < nsids; i++) {
 954                 rc = security_sid_to_context(sids[i], &newcon, &len);
 955                 if (rc) {
 956                         length = rc;
 957                         goto out;
 958                 }
 959                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 960                         kfree(newcon);
 961                         length = -ERANGE;
 962                         goto out;
 963                 }
 964                 memcpy(ptr, newcon, len);
 965                 kfree(newcon);
 966                 ptr += len;
 967                 length += len;
 968         }
 969 out:
 970         kfree(sids);
 971         kfree(user);
 972         kfree(con);
 973         return length;
 974 }
 975
 976 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 977 {
 978         char *scon = NULL, *tcon = NULL;
 979         u32 ssid, tsid, newsid;
 980         u16 tclass;
 981         ssize_t length;
 982         char *newcon = NULL;
 983         u32 len;
 984
 985         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 986         if (length)
 987                 goto out;
 988
 989         length = -ENOMEM;
 990         scon = kzalloc(size + 1, GFP_KERNEL);
 991         if (!scon)
 992                 goto out;
 993
 994         length = -ENOMEM;
 995         tcon = kzalloc(size + 1, GFP_KERNEL);
 996         if (!tcon)
 997                 goto out;
 998
 999         length = -EINVAL;
1000         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1001                 goto out;
1002
1003         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
1004                                          GFP_KERNEL);
1005         if (length)
1006                 goto out;
1007
1008         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
1009                                          GFP_KERNEL);
1010         if (length)
1011                 goto out;
1012
1013         length = security_member_sid(ssid, tsid, tclass, &newsid);
1014         if (length)
1015                 goto out;
1016
1017         length = security_sid_to_context(newsid, &newcon, &len);
1018         if (length)
1019                 goto out;
1020
1021         length = -ERANGE;
1022         if (len > SIMPLE_TRANSACTION_LIMIT) {
1023                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1024                         "payload max\n", __func__, len);
1025                 goto out;
1026         }
1027
1028         memcpy(buf, newcon, len);
1029         length = len;
1030 out:
1031         kfree(newcon);
1032         kfree(tcon);
1033         kfree(scon);
1034         return length;
1035 }
1036
1037 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1038 {
1039         struct inode *ret = new_inode(sb);
1040
1041         if (ret) {
1042                 ret->i_mode = mode;
1043                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1044         }
1045         return ret;
1046 }
1047
1048 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1049                              size_t count, loff_t *ppos)
1050 {
1051         char *page = NULL;
1052         ssize_t length;
1053         ssize_t ret;
1054         int cur_enforcing;
1055         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1056         const char *name = filep->f_path.dentry->d_name.name;
1057
1058         mutex_lock(&sel_mutex);
1059
1060         ret = -EINVAL;
1061         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1062                 goto out;
1063
1064         ret = -ENOMEM;
1065         page = (char *)get_zeroed_page(GFP_KERNEL);
1066         if (!page)
1067                 goto out;
1068
1069         cur_enforcing = security_get_bool_value(index);
1070         if (cur_enforcing < 0) {
1071                 ret = cur_enforcing;
1072                 goto out;
1073         }
1074         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1075                           bool_pending_values[index]);
1076         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1077 out:
1078         mutex_unlock(&sel_mutex);
1079         free_page((unsigned long)page);
1080         return ret;
1081 }
1082
1083 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1084                               size_t count, loff_t *ppos)
1085 {
1086         char *page = NULL;
1087         ssize_t length;
1088         int new_value;
1089         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1090         const char *name = filep->f_path.dentry->d_name.name;
1091
1092         mutex_lock(&sel_mutex);
1093
1094         length = task_has_security(current, SECURITY__SETBOOL);
1095         if (length)
1096                 goto out;
1097
1098         length = -EINVAL;
1099         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1100                 goto out;
1101
1102         length = -ENOMEM;
1103         if (count >= PAGE_SIZE)
1104                 goto out;
1105
1106         /* No partial writes. */
1107         length = -EINVAL;
1108         if (*ppos != 0)
1109                 goto out;
1110
1111         length = -ENOMEM;
1112         page = (char *)get_zeroed_page(GFP_KERNEL);
1113         if (!page)
1114                 goto out;
1115
1116         length = -EFAULT;
1117         if (copy_from_user(page, buf, count))
1118                 goto out;
1119
1120         length = -EINVAL;
1121         if (sscanf(page, "%d", &new_value) != 1)
1122                 goto out;
1123
1124         if (new_value)
1125                 new_value = 1;
1126
1127         bool_pending_values[index] = new_value;
1128         length = count;
1129
1130 out:
1131         mutex_unlock(&sel_mutex);
1132         free_page((unsigned long) page);
1133         return length;
1134 }
1135
1136 static const struct file_operations sel_bool_ops = {
1137         .read           = sel_read_bool,
1138         .write          = sel_write_bool,
1139         .llseek         = generic_file_llseek,
1140 };
1141
1142 static ssize_t sel_commit_bools_write(struct file *filep,
1143                                       const char __user *buf,
1144                                       size_t count, loff_t *ppos)
1145 {
1146         char *page = NULL;
1147         ssize_t length;
1148         int new_value;
1149
1150         mutex_lock(&sel_mutex);
1151
1152         length = task_has_security(current, SECURITY__SETBOOL);
1153         if (length)
1154                 goto out;
1155
1156         length = -ENOMEM;
1157         if (count >= PAGE_SIZE)
1158                 goto out;
1159
1160         /* No partial writes. */
1161         length = -EINVAL;
1162         if (*ppos != 0)
1163                 goto out;
1164
1165         length = -ENOMEM;
1166         page = (char *)get_zeroed_page(GFP_KERNEL);
1167         if (!page)
1168                 goto out;
1169
1170         length = -EFAULT;
1171         if (copy_from_user(page, buf, count))
1172                 goto out;
1173
1174         length = -EINVAL;
1175         if (sscanf(page, "%d", &new_value) != 1)
1176                 goto out;
1177
1178         length = 0;
1179         if (new_value && bool_pending_values)
1180                 length = security_set_bools(bool_num, bool_pending_values);
1181
1182         if (!length)
1183                 length = count;
1184
1185 out:
1186         mutex_unlock(&sel_mutex);
1187         free_page((unsigned long) page);
1188         return length;
1189 }
1190
1191 static const struct file_operations sel_commit_bools_ops = {
1192         .write          = sel_commit_bools_write,
1193         .llseek         = generic_file_llseek,
1194 };
1195
1196 static void sel_remove_entries(struct dentry *de)
1197 {
1198         d_genocide(de);
1199         shrink_dcache_parent(de);
1200 }
1201
1202 #define BOOL_DIR_NAME "booleans"
1203
1204 static int sel_make_bools(void)
1205 {
1206         int i, ret;
1207         ssize_t len;
1208         struct dentry *dentry = NULL;
1209         struct dentry *dir = bool_dir;
1210         struct inode *inode = NULL;
1211         struct inode_security_struct *isec;
1212         char **names = NULL, *page;
1213         int num;
1214         int *values = NULL;
1215         u32 sid;
1216
1217         /* remove any existing files */
1218         for (i = 0; i < bool_num; i++)
1219                 kfree(bool_pending_names[i]);
1220         kfree(bool_pending_names);
1221         kfree(bool_pending_values);
1222         bool_num = 0;
1223         bool_pending_names = NULL;
1224         bool_pending_values = NULL;
1225
1226         sel_remove_entries(dir);
1227
1228         ret = -ENOMEM;
1229         page = (char *)get_zeroed_page(GFP_KERNEL);
1230         if (!page)
1231                 goto out;
1232
1233         ret = security_get_bools(&num, &names, &values);
1234         if (ret)
1235                 goto out;
1236
1237         for (i = 0; i < num; i++) {
1238                 ret = -ENOMEM;
1239                 dentry = d_alloc_name(dir, names[i]);
1240                 if (!dentry)
1241                         goto out;
1242
1243                 ret = -ENOMEM;
1244                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1245                 if (!inode)
1246                         goto out;
1247
1248                 ret = -ENAMETOOLONG;
1249                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1250                 if (len >= PAGE_SIZE)
1251                         goto out;
1252
1253                 isec = (struct inode_security_struct *)inode->i_security;
1254                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1255                 if (ret)
1256                         goto out;
1257
1258                 isec->sid = sid;
1259                 isec->initialized = 1;
1260                 inode->i_fop = &sel_bool_ops;
1261                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1262                 d_add(dentry, inode);
1263         }
1264         bool_num = num;
1265         bool_pending_names = names;
1266         bool_pending_values = values;
1267
1268         free_page((unsigned long)page);
1269         return 0;
1270 out:
1271         free_page((unsigned long)page);
1272
1273         if (names) {
1274                 for (i = 0; i < num; i++)
1275                         kfree(names[i]);
1276                 kfree(names);
1277         }
1278         kfree(values);
1279         sel_remove_entries(dir);
1280
1281         return ret;
1282 }
1283
1284 #define NULL_FILE_NAME "null"
1285
1286 struct path selinux_null;
1287
1288 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1289                                             size_t count, loff_t *ppos)
1290 {
1291         char tmpbuf[TMPBUFLEN];
1292         ssize_t length;
1293
1294         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1295         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1296 }
1297
1298 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1299                                              const char __user *buf,
1300                                              size_t count, loff_t *ppos)
1301
1302 {
1303         char *page = NULL;
1304         ssize_t ret;
1305         int new_value;
1306
1307         ret = task_has_security(current, SECURITY__SETSECPARAM);
1308         if (ret)
1309                 goto out;
1310
1311         ret = -ENOMEM;
1312         if (count >= PAGE_SIZE)
1313                 goto out;
1314
1315         /* No partial writes. */
1316         ret = -EINVAL;
1317         if (*ppos != 0)
1318                 goto out;
1319
1320         ret = -ENOMEM;
1321         page = (char *)get_zeroed_page(GFP_KERNEL);
1322         if (!page)
1323                 goto out;
1324
1325         ret = -EFAULT;
1326         if (copy_from_user(page, buf, count))
1327                 goto out;
1328
1329         ret = -EINVAL;
1330         if (sscanf(page, "%u", &new_value) != 1)
1331                 goto out;
1332
1333         avc_cache_threshold = new_value;
1334
1335         ret = count;
1336 out:
1337         free_page((unsigned long)page);
1338         return ret;
1339 }
1340
1341 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1342                                        size_t count, loff_t *ppos)
1343 {
1344         char *page;
1345         ssize_t length;
1346
1347         page = (char *)__get_free_page(GFP_KERNEL);
1348         if (!page)
1349                 return -ENOMEM;
1350
1351         length = avc_get_hash_stats(page);
1352         if (length >= 0)
1353                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1354         free_page((unsigned long)page);
1355
1356         return length;
1357 }
1358
1359 static const struct file_operations sel_avc_cache_threshold_ops = {
1360         .read           = sel_read_avc_cache_threshold,
1361         .write          = sel_write_avc_cache_threshold,
1362         .llseek         = generic_file_llseek,
1363 };
1364
1365 static const struct file_operations sel_avc_hash_stats_ops = {
1366         .read           = sel_read_avc_hash_stats,
1367         .llseek         = generic_file_llseek,
1368 };
1369
1370 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1371 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1372 {
1373         int cpu;
1374
1375         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1376                 if (!cpu_possible(cpu))
1377                         continue;
1378                 *idx = cpu + 1;
1379                 return &per_cpu(avc_cache_stats, cpu);
1380         }
1381         return NULL;
1382 }
1383
1384 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1385 {
1386         loff_t n = *pos - 1;
1387
1388         if (*pos == 0)
1389                 return SEQ_START_TOKEN;
1390
1391         return sel_avc_get_stat_idx(&n);
1392 }
1393
1394 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1395 {
1396         return sel_avc_get_stat_idx(pos);
1397 }
1398
1399 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1400 {
1401         struct avc_cache_stats *st = v;
1402
1403         if (v == SEQ_START_TOKEN)
1404                 seq_printf(seq, "lookups hits misses allocations reclaims "
1405                            "frees\n");
1406         else {
1407                 unsigned int lookups = st->lookups;
1408                 unsigned int misses = st->misses;
1409                 unsigned int hits = lookups - misses;
1410                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1411                            hits, misses, st->allocations,
1412                            st->reclaims, st->frees);
1413         }
1414         return 0;
1415 }
1416
1417 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1418 { }
1419
1420 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1421         .start          = sel_avc_stats_seq_start,
1422         .next           = sel_avc_stats_seq_next,
1423         .show           = sel_avc_stats_seq_show,
1424         .stop           = sel_avc_stats_seq_stop,
1425 };
1426
1427 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1428 {
1429         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1430 }
1431
1432 static const struct file_operations sel_avc_cache_stats_ops = {
1433         .open           = sel_open_avc_cache_stats,
1434         .read           = seq_read,
1435         .llseek         = seq_lseek,
1436         .release        = seq_release,
1437 };
1438 #endif
1439
1440 static int sel_make_avc_files(struct dentry *dir)
1441 {
1442         int i;
1443         static struct tree_descr files[] = {
1444                 { "cache_threshold",
1445                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1446                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1447 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1448                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1449 #endif
1450         };
1451
1452         for (i = 0; i < ARRAY_SIZE(files); i++) {
1453                 struct inode *inode;
1454                 struct dentry *dentry;
1455
1456                 dentry = d_alloc_name(dir, files[i].name);
1457                 if (!dentry)
1458                         return -ENOMEM;
1459
1460                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1461                 if (!inode)
1462                         return -ENOMEM;
1463
1464                 inode->i_fop = files[i].ops;
1465                 inode->i_ino = ++sel_last_ino;
1466                 d_add(dentry, inode);
1467         }
1468
1469         return 0;
1470 }
1471
1472 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1473                                 size_t count, loff_t *ppos)
1474 {
1475         char *con;
1476         u32 sid, len;
1477         ssize_t ret;
1478
1479         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1480         ret = security_sid_to_context(sid, &con, &len);
1481         if (ret)
1482                 return ret;
1483
1484         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1485         kfree(con);
1486         return ret;
1487 }
1488
1489 static const struct file_operations sel_initcon_ops = {
1490         .read           = sel_read_initcon,
1491         .llseek         = generic_file_llseek,
1492 };
1493
1494 static int sel_make_initcon_files(struct dentry *dir)
1495 {
1496         int i;
1497
1498         for (i = 1; i <= SECINITSID_NUM; i++) {
1499                 struct inode *inode;
1500                 struct dentry *dentry;
1501                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1502                 if (!dentry)
1503                         return -ENOMEM;
1504
1505                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1506                 if (!inode)
1507                         return -ENOMEM;
1508
1509                 inode->i_fop = &sel_initcon_ops;
1510                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1511                 d_add(dentry, inode);
1512         }
1513
1514         return 0;
1515 }
1516
1517 static inline unsigned long sel_class_to_ino(u16 class)
1518 {
1519         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1520 }
1521
1522 static inline u16 sel_ino_to_class(unsigned long ino)
1523 {
1524         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1525 }
1526
1527 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1528 {
1529         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1530 }
1531
1532 static inline u32 sel_ino_to_perm(unsigned long ino)
1533 {
1534         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1535 }
1536
1537 static ssize_t sel_read_class(struct file *file, char __user *buf,
1538                                 size_t count, loff_t *ppos)
1539 {
1540         unsigned long ino = file_inode(file)->i_ino;
1541         char res[TMPBUFLEN];
1542         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1543         return simple_read_from_buffer(buf, count, ppos, res, len);
1544 }
1545
1546 static const struct file_operations sel_class_ops = {
1547         .read           = sel_read_class,
1548         .llseek         = generic_file_llseek,
1549 };
1550
1551 static ssize_t sel_read_perm(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_perm(ino));
1557         return simple_read_from_buffer(buf, count, ppos, res, len);
1558 }
1559
1560 static const struct file_operations sel_perm_ops = {
1561         .read           = sel_read_perm,
1562         .llseek         = generic_file_llseek,
1563 };
1564
1565 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1566                                   size_t count, loff_t *ppos)
1567 {
1568         int value;
1569         char tmpbuf[TMPBUFLEN];
1570         ssize_t length;
1571         unsigned long i_ino = file_inode(file)->i_ino;
1572
1573         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1574         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1575
1576         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1577 }
1578
1579 static const struct file_operations sel_policycap_ops = {
1580         .read           = sel_read_policycap,
1581         .llseek         = generic_file_llseek,
1582 };
1583
1584 static int sel_make_perm_files(char *objclass, int classvalue,
1585                                 struct dentry *dir)
1586 {
1587         int i, rc, nperms;
1588         char **perms;
1589
1590         rc = security_get_permissions(objclass, &perms, &nperms);
1591         if (rc)
1592                 return rc;
1593
1594         for (i = 0; i < nperms; i++) {
1595                 struct inode *inode;
1596                 struct dentry *dentry;
1597
1598                 rc = -ENOMEM;
1599                 dentry = d_alloc_name(dir, perms[i]);
1600                 if (!dentry)
1601                         goto out;
1602
1603                 rc = -ENOMEM;
1604                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1605                 if (!inode)
1606                         goto out;
1607
1608                 inode->i_fop = &sel_perm_ops;
1609                 /* i+1 since perm values are 1-indexed */
1610                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1611                 d_add(dentry, inode);
1612         }
1613         rc = 0;
1614 out:
1615         for (i = 0; i < nperms; i++)
1616                 kfree(perms[i]);
1617         kfree(perms);
1618         return rc;
1619 }
1620
1621 static int sel_make_class_dir_entries(char *classname, int index,
1622                                         struct dentry *dir)
1623 {
1624         struct dentry *dentry = NULL;
1625         struct inode *inode = NULL;
1626         int rc;
1627
1628         dentry = d_alloc_name(dir, "index");
1629         if (!dentry)
1630                 return -ENOMEM;
1631
1632         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1633         if (!inode)
1634                 return -ENOMEM;
1635
1636         inode->i_fop = &sel_class_ops;
1637         inode->i_ino = sel_class_to_ino(index);
1638         d_add(dentry, inode);
1639
1640         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1641         if (IS_ERR(dentry))
1642                 return PTR_ERR(dentry);
1643
1644         rc = sel_make_perm_files(classname, index, dentry);
1645
1646         return rc;
1647 }
1648
1649 static int sel_make_classes(void)
1650 {
1651         int rc, nclasses, i;
1652         char **classes;
1653
1654         /* delete any existing entries */
1655         sel_remove_entries(class_dir);
1656
1657         rc = security_get_classes(&classes, &nclasses);
1658         if (rc)
1659                 return rc;
1660
1661         /* +2 since classes are 1-indexed */
1662         last_class_ino = sel_class_to_ino(nclasses + 2);
1663
1664         for (i = 0; i < nclasses; i++) {
1665                 struct dentry *class_name_dir;
1666
1667                 class_name_dir = sel_make_dir(class_dir, classes[i],
1668                                 &last_class_ino);
1669                 if (IS_ERR(class_name_dir)) {
1670                         rc = PTR_ERR(class_name_dir);
1671                         goto out;
1672                 }
1673
1674                 /* i+1 since class values are 1-indexed */
1675                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1676                                 class_name_dir);
1677                 if (rc)
1678                         goto out;
1679         }
1680         rc = 0;
1681 out:
1682         for (i = 0; i < nclasses; i++)
1683                 kfree(classes[i]);
1684         kfree(classes);
1685         return rc;
1686 }
1687
1688 static int sel_make_policycap(void)
1689 {
1690         unsigned int iter;
1691         struct dentry *dentry = NULL;
1692         struct inode *inode = NULL;
1693
1694         sel_remove_entries(policycap_dir);
1695
1696         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1697                 if (iter < ARRAY_SIZE(policycap_names))
1698                         dentry = d_alloc_name(policycap_dir,
1699                                               policycap_names[iter]);
1700                 else
1701                         dentry = d_alloc_name(policycap_dir, "unknown");
1702
1703                 if (dentry == NULL)
1704                         return -ENOMEM;
1705
1706                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1707                 if (inode == NULL)
1708                         return -ENOMEM;
1709
1710                 inode->i_fop = &sel_policycap_ops;
1711                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1712                 d_add(dentry, inode);
1713         }
1714
1715         return 0;
1716 }
1717
1718 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1719                         unsigned long *ino)
1720 {
1721         struct dentry *dentry = d_alloc_name(dir, name);
1722         struct inode *inode;
1723
1724         if (!dentry)
1725                 return ERR_PTR(-ENOMEM);
1726
1727         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1728         if (!inode) {
1729                 dput(dentry);
1730                 return ERR_PTR(-ENOMEM);
1731         }
1732
1733         inode->i_op = &simple_dir_inode_operations;
1734         inode->i_fop = &simple_dir_operations;
1735         inode->i_ino = ++(*ino);
1736         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1737         inc_nlink(inode);
1738         d_add(dentry, inode);
1739         /* bump link count on parent directory, too */
1740         inc_nlink(d_inode(dir));
1741
1742         return dentry;
1743 }
1744
1745 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1746 {
1747         int ret;
1748         struct dentry *dentry;
1749         struct inode *inode;
1750         struct inode_security_struct *isec;
1751
1752         static struct tree_descr selinux_files[] = {
1753                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1754                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1755                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1756                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1757                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1758                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1759                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1760                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1761                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1762                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1763                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1764                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1765                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1766                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1767                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1768                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1769                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1770                 /* last one */ {""}
1771         };
1772         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1773         if (ret)
1774                 goto err;
1775
1776         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1777         if (IS_ERR(bool_dir)) {
1778                 ret = PTR_ERR(bool_dir);
1779                 bool_dir = NULL;
1780                 goto err;
1781         }
1782
1783         ret = -ENOMEM;
1784         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1785         if (!dentry)
1786                 goto err;
1787
1788         ret = -ENOMEM;
1789         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1790         if (!inode)
1791                 goto err;
1792
1793         inode->i_ino = ++sel_last_ino;
1794         isec = (struct inode_security_struct *)inode->i_security;
1795         isec->sid = SECINITSID_DEVNULL;
1796         isec->sclass = SECCLASS_CHR_FILE;
1797         isec->initialized = 1;
1798
1799         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1800         d_add(dentry, inode);
1801         selinux_null.dentry = dentry;
1802
1803         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1804         if (IS_ERR(dentry)) {
1805                 ret = PTR_ERR(dentry);
1806                 goto err;
1807         }
1808
1809         ret = sel_make_avc_files(dentry);
1810         if (ret)
1811                 goto err;
1812
1813         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1814         if (IS_ERR(dentry)) {
1815                 ret = PTR_ERR(dentry);
1816                 goto err;
1817         }
1818
1819         ret = sel_make_initcon_files(dentry);
1820         if (ret)
1821                 goto err;
1822
1823         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1824         if (IS_ERR(class_dir)) {
1825                 ret = PTR_ERR(class_dir);
1826                 class_dir = NULL;
1827                 goto err;
1828         }
1829
1830         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1831         if (IS_ERR(policycap_dir)) {
1832                 ret = PTR_ERR(policycap_dir);
1833                 policycap_dir = NULL;
1834                 goto err;
1835         }
1836         return 0;
1837 err:
1838         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1839                 __func__);
1840         return ret;
1841 }
1842
1843 static struct dentry *sel_mount(struct file_system_type *fs_type,
1844                       int flags, const char *dev_name, void *data)
1845 {
1846         return mount_single(fs_type, flags, data, sel_fill_super);
1847 }
1848
1849 static struct file_system_type sel_fs_type = {
1850         .name           = "selinuxfs",
1851         .mount          = sel_mount,
1852         .kill_sb        = kill_litter_super,
1853 };
1854
1855 struct vfsmount *selinuxfs_mount;
1856
1857 static int __init init_sel_fs(void)
1858 {
1859         int err;
1860
1861         if (!selinux_enabled)
1862                 return 0;
1863
1864         err = sysfs_create_mount_point(fs_kobj, "selinux");
1865         if (err)
1866                 return err;
1867
1868         err = register_filesystem(&sel_fs_type);
1869         if (err) {
1870                 sysfs_remove_mount_point(fs_kobj, "selinux");
1871                 return err;
1872         }
1873
1874         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1875         if (IS_ERR(selinuxfs_mount)) {
1876                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1877                 err = PTR_ERR(selinuxfs_mount);
1878                 selinuxfs_mount = NULL;
1879         }
1880
1881         return err;
1882 }
1883
1884 __initcall(init_sel_fs);
1885
1886 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1887 void exit_sel_fs(void)
1888 {
1889         sysfs_remove_mount_point(fs_kobj, "selinux");
1890         kern_unmount(selinuxfs_mount);
1891         unregister_filesystem(&sel_fs_type);
1892 }
1893 #endif