kernel/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 const 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_str_to_sid(scon, &ssid, GFP_KERNEL);
 735         if (length)
 736                 goto out;
 737
 738         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 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_str_to_sid(scon, &ssid, GFP_KERNEL);
 821         if (length)
 822                 goto out;
 823
 824         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 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_str_to_sid(scon, &ssid, GFP_KERNEL);
 882         if (length)
 883                 goto out;
 884
 885         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 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_str_to_sid(con, &sid, GFP_KERNEL);
 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_str_to_sid(scon, &ssid, GFP_KERNEL);
 998         if (length)
 999                 goto out;
1000
1001         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
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         d_genocide(de);
1191         shrink_dcache_parent(de);
1192 }
1193
1194 #define BOOL_DIR_NAME "booleans"
1195
1196 static int sel_make_bools(void)
1197 {
1198         int i, ret;
1199         ssize_t len;
1200         struct dentry *dentry = NULL;
1201         struct dentry *dir = bool_dir;
1202         struct inode *inode = NULL;
1203         struct inode_security_struct *isec;
1204         char **names = NULL, *page;
1205         int num;
1206         int *values = NULL;
1207         u32 sid;
1208
1209         /* remove any existing files */
1210         for (i = 0; i < bool_num; i++)
1211                 kfree(bool_pending_names[i]);
1212         kfree(bool_pending_names);
1213         kfree(bool_pending_values);
1214         bool_num = 0;
1215         bool_pending_names = NULL;
1216         bool_pending_values = NULL;
1217
1218         sel_remove_entries(dir);
1219
1220         ret = -ENOMEM;
1221         page = (char *)get_zeroed_page(GFP_KERNEL);
1222         if (!page)
1223                 goto out;
1224
1225         ret = security_get_bools(&num, &names, &values);
1226         if (ret)
1227                 goto out;
1228
1229         for (i = 0; i < num; i++) {
1230                 ret = -ENOMEM;
1231                 dentry = d_alloc_name(dir, names[i]);
1232                 if (!dentry)
1233                         goto out;
1234
1235                 ret = -ENOMEM;
1236                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1237                 if (!inode)
1238                         goto out;
1239
1240                 ret = -ENAMETOOLONG;
1241                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1242                 if (len >= PAGE_SIZE)
1243                         goto out;
1244
1245                 isec = (struct inode_security_struct *)inode->i_security;
1246                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1247                 if (ret)
1248                         goto out;
1249
1250                 isec->sid = sid;
1251                 isec->initialized = 1;
1252                 inode->i_fop = &sel_bool_ops;
1253                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1254                 d_add(dentry, inode);
1255         }
1256         bool_num = num;
1257         bool_pending_names = names;
1258         bool_pending_values = values;
1259
1260         free_page((unsigned long)page);
1261         return 0;
1262 out:
1263         free_page((unsigned long)page);
1264
1265         if (names) {
1266                 for (i = 0; i < num; i++)
1267                         kfree(names[i]);
1268                 kfree(names);
1269         }
1270         kfree(values);
1271         sel_remove_entries(dir);
1272
1273         return ret;
1274 }
1275
1276 #define NULL_FILE_NAME "null"
1277
1278 struct path selinux_null;
1279
1280 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1281                                             size_t count, loff_t *ppos)
1282 {
1283         char tmpbuf[TMPBUFLEN];
1284         ssize_t length;
1285
1286         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1287         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1288 }
1289
1290 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1291                                              const char __user *buf,
1292                                              size_t count, loff_t *ppos)
1293
1294 {
1295         char *page = NULL;
1296         ssize_t ret;
1297         int new_value;
1298
1299         ret = task_has_security(current, SECURITY__SETSECPARAM);
1300         if (ret)
1301                 goto out;
1302
1303         ret = -ENOMEM;
1304         if (count >= PAGE_SIZE)
1305                 goto out;
1306
1307         /* No partial writes. */
1308         ret = -EINVAL;
1309         if (*ppos != 0)
1310                 goto out;
1311
1312         ret = -ENOMEM;
1313         page = (char *)get_zeroed_page(GFP_KERNEL);
1314         if (!page)
1315                 goto out;
1316
1317         ret = -EFAULT;
1318         if (copy_from_user(page, buf, count))
1319                 goto out;
1320
1321         ret = -EINVAL;
1322         if (sscanf(page, "%u", &new_value) != 1)
1323                 goto out;
1324
1325         avc_cache_threshold = new_value;
1326
1327         ret = count;
1328 out:
1329         free_page((unsigned long)page);
1330         return ret;
1331 }
1332
1333 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1334                                        size_t count, loff_t *ppos)
1335 {
1336         char *page;
1337         ssize_t length;
1338
1339         page = (char *)__get_free_page(GFP_KERNEL);
1340         if (!page)
1341                 return -ENOMEM;
1342
1343         length = avc_get_hash_stats(page);
1344         if (length >= 0)
1345                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1346         free_page((unsigned long)page);
1347
1348         return length;
1349 }
1350
1351 static const struct file_operations sel_avc_cache_threshold_ops = {
1352         .read           = sel_read_avc_cache_threshold,
1353         .write          = sel_write_avc_cache_threshold,
1354         .llseek         = generic_file_llseek,
1355 };
1356
1357 static const struct file_operations sel_avc_hash_stats_ops = {
1358         .read           = sel_read_avc_hash_stats,
1359         .llseek         = generic_file_llseek,
1360 };
1361
1362 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1363 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1364 {
1365         int cpu;
1366
1367         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1368                 if (!cpu_possible(cpu))
1369                         continue;
1370                 *idx = cpu + 1;
1371                 return &per_cpu(avc_cache_stats, cpu);
1372         }
1373         return NULL;
1374 }
1375
1376 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1377 {
1378         loff_t n = *pos - 1;
1379
1380         if (*pos == 0)
1381                 return SEQ_START_TOKEN;
1382
1383         return sel_avc_get_stat_idx(&n);
1384 }
1385
1386 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1387 {
1388         return sel_avc_get_stat_idx(pos);
1389 }
1390
1391 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1392 {
1393         struct avc_cache_stats *st = v;
1394
1395         if (v == SEQ_START_TOKEN)
1396                 seq_printf(seq, "lookups hits misses allocations reclaims "
1397                            "frees\n");
1398         else {
1399                 unsigned int lookups = st->lookups;
1400                 unsigned int misses = st->misses;
1401                 unsigned int hits = lookups - misses;
1402                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1403                            hits, misses, st->allocations,
1404                            st->reclaims, st->frees);
1405         }
1406         return 0;
1407 }
1408
1409 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1410 { }
1411
1412 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1413         .start          = sel_avc_stats_seq_start,
1414         .next           = sel_avc_stats_seq_next,
1415         .show           = sel_avc_stats_seq_show,
1416         .stop           = sel_avc_stats_seq_stop,
1417 };
1418
1419 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1420 {
1421         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1422 }
1423
1424 static const struct file_operations sel_avc_cache_stats_ops = {
1425         .open           = sel_open_avc_cache_stats,
1426         .read           = seq_read,
1427         .llseek         = seq_lseek,
1428         .release        = seq_release,
1429 };
1430 #endif
1431
1432 static int sel_make_avc_files(struct dentry *dir)
1433 {
1434         int i;
1435         static struct tree_descr files[] = {
1436                 { "cache_threshold",
1437                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1438                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1439 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1440                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1441 #endif
1442         };
1443
1444         for (i = 0; i < ARRAY_SIZE(files); i++) {
1445                 struct inode *inode;
1446                 struct dentry *dentry;
1447
1448                 dentry = d_alloc_name(dir, files[i].name);
1449                 if (!dentry)
1450                         return -ENOMEM;
1451
1452                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1453                 if (!inode)
1454                         return -ENOMEM;
1455
1456                 inode->i_fop = files[i].ops;
1457                 inode->i_ino = ++sel_last_ino;
1458                 d_add(dentry, inode);
1459         }
1460
1461         return 0;
1462 }
1463
1464 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1465                                 size_t count, loff_t *ppos)
1466 {
1467         char *con;
1468         u32 sid, len;
1469         ssize_t ret;
1470
1471         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1472         ret = security_sid_to_context(sid, &con, &len);
1473         if (ret)
1474                 return ret;
1475
1476         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1477         kfree(con);
1478         return ret;
1479 }
1480
1481 static const struct file_operations sel_initcon_ops = {
1482         .read           = sel_read_initcon,
1483         .llseek         = generic_file_llseek,
1484 };
1485
1486 static int sel_make_initcon_files(struct dentry *dir)
1487 {
1488         int i;
1489
1490         for (i = 1; i <= SECINITSID_NUM; i++) {
1491                 struct inode *inode;
1492                 struct dentry *dentry;
1493                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1494                 if (!dentry)
1495                         return -ENOMEM;
1496
1497                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1498                 if (!inode)
1499                         return -ENOMEM;
1500
1501                 inode->i_fop = &sel_initcon_ops;
1502                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1503                 d_add(dentry, inode);
1504         }
1505
1506         return 0;
1507 }
1508
1509 static inline unsigned long sel_class_to_ino(u16 class)
1510 {
1511         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1512 }
1513
1514 static inline u16 sel_ino_to_class(unsigned long ino)
1515 {
1516         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1517 }
1518
1519 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1520 {
1521         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1522 }
1523
1524 static inline u32 sel_ino_to_perm(unsigned long ino)
1525 {
1526         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1527 }
1528
1529 static ssize_t sel_read_class(struct file *file, char __user *buf,
1530                                 size_t count, loff_t *ppos)
1531 {
1532         unsigned long ino = file_inode(file)->i_ino;
1533         char res[TMPBUFLEN];
1534         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1535         return simple_read_from_buffer(buf, count, ppos, res, len);
1536 }
1537
1538 static const struct file_operations sel_class_ops = {
1539         .read           = sel_read_class,
1540         .llseek         = generic_file_llseek,
1541 };
1542
1543 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1544                                 size_t count, loff_t *ppos)
1545 {
1546         unsigned long ino = file_inode(file)->i_ino;
1547         char res[TMPBUFLEN];
1548         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1549         return simple_read_from_buffer(buf, count, ppos, res, len);
1550 }
1551
1552 static const struct file_operations sel_perm_ops = {
1553         .read           = sel_read_perm,
1554         .llseek         = generic_file_llseek,
1555 };
1556
1557 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1558                                   size_t count, loff_t *ppos)
1559 {
1560         int value;
1561         char tmpbuf[TMPBUFLEN];
1562         ssize_t length;
1563         unsigned long i_ino = file_inode(file)->i_ino;
1564
1565         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1566         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1567
1568         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1569 }
1570
1571 static const struct file_operations sel_policycap_ops = {
1572         .read           = sel_read_policycap,
1573         .llseek         = generic_file_llseek,
1574 };
1575
1576 static int sel_make_perm_files(char *objclass, int classvalue,
1577                                 struct dentry *dir)
1578 {
1579         int i, rc, nperms;
1580         char **perms;
1581
1582         rc = security_get_permissions(objclass, &perms, &nperms);
1583         if (rc)
1584                 return rc;
1585
1586         for (i = 0; i < nperms; i++) {
1587                 struct inode *inode;
1588                 struct dentry *dentry;
1589
1590                 rc = -ENOMEM;
1591                 dentry = d_alloc_name(dir, perms[i]);
1592                 if (!dentry)
1593                         goto out;
1594
1595                 rc = -ENOMEM;
1596                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1597                 if (!inode)
1598                         goto out;
1599
1600                 inode->i_fop = &sel_perm_ops;
1601                 /* i+1 since perm values are 1-indexed */
1602                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1603                 d_add(dentry, inode);
1604         }
1605         rc = 0;
1606 out:
1607         for (i = 0; i < nperms; i++)
1608                 kfree(perms[i]);
1609         kfree(perms);
1610         return rc;
1611 }
1612
1613 static int sel_make_class_dir_entries(char *classname, int index,
1614                                         struct dentry *dir)
1615 {
1616         struct dentry *dentry = NULL;
1617         struct inode *inode = NULL;
1618         int rc;
1619
1620         dentry = d_alloc_name(dir, "index");
1621         if (!dentry)
1622                 return -ENOMEM;
1623
1624         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1625         if (!inode)
1626                 return -ENOMEM;
1627
1628         inode->i_fop = &sel_class_ops;
1629         inode->i_ino = sel_class_to_ino(index);
1630         d_add(dentry, inode);
1631
1632         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1633         if (IS_ERR(dentry))
1634                 return PTR_ERR(dentry);
1635
1636         rc = sel_make_perm_files(classname, index, dentry);
1637
1638         return rc;
1639 }
1640
1641 static int sel_make_classes(void)
1642 {
1643         int rc, nclasses, i;
1644         char **classes;
1645
1646         /* delete any existing entries */
1647         sel_remove_entries(class_dir);
1648
1649         rc = security_get_classes(&classes, &nclasses);
1650         if (rc)
1651                 return rc;
1652
1653         /* +2 since classes are 1-indexed */
1654         last_class_ino = sel_class_to_ino(nclasses + 2);
1655
1656         for (i = 0; i < nclasses; i++) {
1657                 struct dentry *class_name_dir;
1658
1659                 class_name_dir = sel_make_dir(class_dir, classes[i],
1660                                 &last_class_ino);
1661                 if (IS_ERR(class_name_dir)) {
1662                         rc = PTR_ERR(class_name_dir);
1663                         goto out;
1664                 }
1665
1666                 /* i+1 since class values are 1-indexed */
1667                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1668                                 class_name_dir);
1669                 if (rc)
1670                         goto out;
1671         }
1672         rc = 0;
1673 out:
1674         for (i = 0; i < nclasses; i++)
1675                 kfree(classes[i]);
1676         kfree(classes);
1677         return rc;
1678 }
1679
1680 static int sel_make_policycap(void)
1681 {
1682         unsigned int iter;
1683         struct dentry *dentry = NULL;
1684         struct inode *inode = NULL;
1685
1686         sel_remove_entries(policycap_dir);
1687
1688         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1689                 if (iter < ARRAY_SIZE(policycap_names))
1690                         dentry = d_alloc_name(policycap_dir,
1691                                               policycap_names[iter]);
1692                 else
1693                         dentry = d_alloc_name(policycap_dir, "unknown");
1694
1695                 if (dentry == NULL)
1696                         return -ENOMEM;
1697
1698                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1699                 if (inode == NULL)
1700                         return -ENOMEM;
1701
1702                 inode->i_fop = &sel_policycap_ops;
1703                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1704                 d_add(dentry, inode);
1705         }
1706
1707         return 0;
1708 }
1709
1710 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1711                         unsigned long *ino)
1712 {
1713         struct dentry *dentry = d_alloc_name(dir, name);
1714         struct inode *inode;
1715
1716         if (!dentry)
1717                 return ERR_PTR(-ENOMEM);
1718
1719         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1720         if (!inode) {
1721                 dput(dentry);
1722                 return ERR_PTR(-ENOMEM);
1723         }
1724
1725         inode->i_op = &simple_dir_inode_operations;
1726         inode->i_fop = &simple_dir_operations;
1727         inode->i_ino = ++(*ino);
1728         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1729         inc_nlink(inode);
1730         d_add(dentry, inode);
1731         /* bump link count on parent directory, too */
1732         inc_nlink(d_inode(dir));
1733
1734         return dentry;
1735 }
1736
1737 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1738 {
1739         int ret;
1740         struct dentry *dentry;
1741         struct inode *inode;
1742         struct inode_security_struct *isec;
1743
1744         static struct tree_descr selinux_files[] = {
1745                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1746                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1747                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1748                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1749                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1750                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1751                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1752                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1753                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1754                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1755                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1756                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1757                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1758                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1759                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1760                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1761                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1762                 /* last one */ {""}
1763         };
1764         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1765         if (ret)
1766                 goto err;
1767
1768         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1769         if (IS_ERR(bool_dir)) {
1770                 ret = PTR_ERR(bool_dir);
1771                 bool_dir = NULL;
1772                 goto err;
1773         }
1774
1775         ret = -ENOMEM;
1776         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1777         if (!dentry)
1778                 goto err;
1779
1780         ret = -ENOMEM;
1781         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1782         if (!inode)
1783                 goto err;
1784
1785         inode->i_ino = ++sel_last_ino;
1786         isec = (struct inode_security_struct *)inode->i_security;
1787         isec->sid = SECINITSID_DEVNULL;
1788         isec->sclass = SECCLASS_CHR_FILE;
1789         isec->initialized = 1;
1790
1791         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1792         d_add(dentry, inode);
1793         selinux_null.dentry = dentry;
1794
1795         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1796         if (IS_ERR(dentry)) {
1797                 ret = PTR_ERR(dentry);
1798                 goto err;
1799         }
1800
1801         ret = sel_make_avc_files(dentry);
1802         if (ret)
1803                 goto err;
1804
1805         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1806         if (IS_ERR(dentry)) {
1807                 ret = PTR_ERR(dentry);
1808                 goto err;
1809         }
1810
1811         ret = sel_make_initcon_files(dentry);
1812         if (ret)
1813                 goto err;
1814
1815         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1816         if (IS_ERR(class_dir)) {
1817                 ret = PTR_ERR(class_dir);
1818                 class_dir = NULL;
1819                 goto err;
1820         }
1821
1822         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1823         if (IS_ERR(policycap_dir)) {
1824                 ret = PTR_ERR(policycap_dir);
1825                 policycap_dir = NULL;
1826                 goto err;
1827         }
1828         return 0;
1829 err:
1830         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1831                 __func__);
1832         return ret;
1833 }
1834
1835 static struct dentry *sel_mount(struct file_system_type *fs_type,
1836                       int flags, const char *dev_name, void *data)
1837 {
1838         return mount_single(fs_type, flags, data, sel_fill_super);
1839 }
1840
1841 static struct file_system_type sel_fs_type = {
1842         .name           = "selinuxfs",
1843         .mount          = sel_mount,
1844         .kill_sb        = kill_litter_super,
1845 };
1846
1847 struct vfsmount *selinuxfs_mount;
1848
1849 static int __init init_sel_fs(void)
1850 {
1851         int err;
1852
1853         if (!selinux_enabled)
1854                 return 0;
1855
1856         err = sysfs_create_mount_point(fs_kobj, "selinux");
1857         if (err)
1858                 return err;
1859
1860         err = register_filesystem(&sel_fs_type);
1861         if (err) {
1862                 sysfs_remove_mount_point(fs_kobj, "selinux");
1863                 return err;
1864         }
1865
1866         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1867         if (IS_ERR(selinuxfs_mount)) {
1868                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1869                 err = PTR_ERR(selinuxfs_mount);
1870                 selinuxfs_mount = NULL;
1871         }
1872
1873         return err;
1874 }
1875
1876 __initcall(init_sel_fs);
1877
1878 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1879 void exit_sel_fs(void)
1880 {
1881         sysfs_remove_mount_point(fs_kobj, "selinux");
1882         kern_unmount(selinuxfs_mount);
1883         unregister_filesystem(&sel_fs_type);
1884 }
1885 #endif