security/selinux/selinuxfs.c

   1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
   2  *
   3  *      Added conditional policy language extensions
   4  *
   5  *  Updated: Hewlett-Packard <paul@paul-moore.com>
   6  *
   7  *      Added support for the policy capability bitmap
   8  *
   9  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  10  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  11  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  12  *      This program is free software; you can redistribute it and/or modify
  13  *      it under the terms of the GNU General Public License as published by
  14  *      the Free Software Foundation, version 2.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/slab.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/fs.h>
  22 #include <linux/mutex.h>
  23 #include <linux/init.h>
  24 #include <linux/string.h>
  25 #include <linux/security.h>
  26 #include <linux/major.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/percpu.h>
  29 #include <linux/audit.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/kobject.h>
  32 #include <linux/ctype.h>
  33
  34 /* selinuxfs pseudo filesystem for exporting the security policy API.
  35    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  36
  37 #include "flask.h"
  38 #include "avc.h"
  39 #include "avc_ss.h"
  40 #include "security.h"
  41 #include "objsec.h"
  42 #include "conditional.h"
  43
  44 /* Policy capability filenames */
  45 static char *policycap_names[] = {
  46         "network_peer_controls",
  47         "open_perms"
  48 };
  49
  50 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  51
  52 static int __init checkreqprot_setup(char *str)
  53 {
  54         unsigned long checkreqprot;
  55         if (!strict_strtoul(str, 0, &checkreqprot))
  56                 selinux_checkreqprot = checkreqprot ? 1 : 0;
  57         return 1;
  58 }
  59 __setup("checkreqprot=", checkreqprot_setup);
  60
  61 static DEFINE_MUTEX(sel_mutex);
  62
  63 /* global data for booleans */
  64 static struct dentry *bool_dir;
  65 static int bool_num;
  66 static char **bool_pending_names;
  67 static int *bool_pending_values;
  68
  69 /* global data for classes */
  70 static struct dentry *class_dir;
  71 static unsigned long last_class_ino;
  72
  73 static char policy_opened;
  74
  75 /* global data for policy capabilities */
  76 static struct dentry *policycap_dir;
  77
  78 /* Check whether a task is allowed to use a security operation. */
  79 static int task_has_security(struct task_struct *tsk,
  80                              u32 perms)
  81 {
  82         const struct task_security_struct *tsec;
  83         u32 sid = 0;
  84
  85         rcu_read_lock();
  86         tsec = __task_cred(tsk)->security;
  87         if (tsec)
  88                 sid = tsec->sid;
  89         rcu_read_unlock();
  90         if (!tsec)
  91                 return -EACCES;
  92
  93         return avc_has_perm(sid, SECINITSID_SECURITY,
  94                             SECCLASS_SECURITY, perms, NULL);
  95 }
  96
  97 enum sel_inos {
  98         SEL_ROOT_INO = 2,
  99         SEL_LOAD,       /* load policy */
 100         SEL_ENFORCE,    /* get or set enforcing status */
 101         SEL_CONTEXT,    /* validate context */
 102         SEL_ACCESS,     /* compute access decision */
 103         SEL_CREATE,     /* compute create labeling decision */
 104         SEL_RELABEL,    /* compute relabeling decision */
 105         SEL_USER,       /* compute reachable user contexts */
 106         SEL_POLICYVERS, /* return policy version for this kernel */
 107         SEL_COMMIT_BOOLS, /* commit new boolean values */
 108         SEL_MLS,        /* return if MLS policy is enabled */
 109         SEL_DISABLE,    /* disable SELinux until next reboot */
 110         SEL_MEMBER,     /* compute polyinstantiation membership decision */
 111         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 112         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 113         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
 114         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 115         SEL_STATUS,     /* export current status using mmap() */
 116         SEL_POLICY,     /* allow userspace to read the in kernel policy */
 117         SEL_INO_NEXT,   /* The next inode number to use */
 118 };
 119
 120 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 121
 122 #define SEL_INITCON_INO_OFFSET          0x01000000
 123 #define SEL_BOOL_INO_OFFSET             0x02000000
 124 #define SEL_CLASS_INO_OFFSET            0x04000000
 125 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
 126 #define SEL_INO_MASK                    0x00ffffff
 127
 128 #define TMPBUFLEN       12
 129 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 130                                 size_t count, loff_t *ppos)
 131 {
 132         char tmpbuf[TMPBUFLEN];
 133         ssize_t length;
 134
 135         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 136         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 137 }
 138
 139 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 140 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 141                                  size_t count, loff_t *ppos)
 142
 143 {
 144         char *page = NULL;
 145         ssize_t length;
 146         int new_value;
 147
 148         length = -ENOMEM;
 149         if (count >= PAGE_SIZE)
 150                 goto out;
 151
 152         /* No partial writes. */
 153         length = -EINVAL;
 154         if (*ppos != 0)
 155                 goto out;
 156
 157         length = -ENOMEM;
 158         page = (char *)get_zeroed_page(GFP_KERNEL);
 159         if (!page)
 160                 goto out;
 161
 162         length = -EFAULT;
 163         if (copy_from_user(page, buf, count))
 164                 goto out;
 165
 166         length = -EINVAL;
 167         if (sscanf(page, "%d", &new_value) != 1)
 168                 goto out;
 169
 170         if (new_value != selinux_enforcing) {
 171                 length = task_has_security(current, SECURITY__SETENFORCE);
 172                 if (length)
 173                         goto out;
 174                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 175                         "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 176                         new_value, selinux_enforcing,
 177                         audit_get_loginuid(current),
 178                         audit_get_sessionid(current));
 179                 selinux_enforcing = new_value;
 180                 if (selinux_enforcing)
 181                         avc_ss_reset(0);
 182                 selnl_notify_setenforce(selinux_enforcing);
 183                 selinux_status_update_setenforce(selinux_enforcing);
 184         }
 185         length = count;
 186 out:
 187         free_page((unsigned long) page);
 188         return length;
 189 }
 190 #else
 191 #define sel_write_enforce NULL
 192 #endif
 193
 194 static const struct file_operations sel_enforce_ops = {
 195         .read           = sel_read_enforce,
 196         .write          = sel_write_enforce,
 197         .llseek         = generic_file_llseek,
 198 };
 199
 200 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 201                                         size_t count, loff_t *ppos)
 202 {
 203         char tmpbuf[TMPBUFLEN];
 204         ssize_t length;
 205         ino_t ino = filp->f_path.dentry->d_inode->i_ino;
 206         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 207                 security_get_reject_unknown() : !security_get_allow_unknown();
 208
 209         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 210         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 211 }
 212
 213 static const struct file_operations sel_handle_unknown_ops = {
 214         .read           = sel_read_handle_unknown,
 215         .llseek         = generic_file_llseek,
 216 };
 217
 218 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 219 {
 220         struct page    *status = selinux_kernel_status_page();
 221
 222         if (!status)
 223                 return -ENOMEM;
 224
 225         filp->private_data = status;
 226
 227         return 0;
 228 }
 229
 230 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 231                                       size_t count, loff_t *ppos)
 232 {
 233         struct page    *status = filp->private_data;
 234
 235         BUG_ON(!status);
 236
 237         return simple_read_from_buffer(buf, count, ppos,
 238                                        page_address(status),
 239                                        sizeof(struct selinux_kernel_status));
 240 }
 241
 242 static int sel_mmap_handle_status(struct file *filp,
 243                                   struct vm_area_struct *vma)
 244 {
 245         struct page    *status = filp->private_data;
 246         unsigned long   size = vma->vm_end - vma->vm_start;
 247
 248         BUG_ON(!status);
 249
 250         /* only allows one page from the head */
 251         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 252                 return -EIO;
 253         /* disallow writable mapping */
 254         if (vma->vm_flags & VM_WRITE)
 255                 return -EPERM;
 256         /* disallow mprotect() turns it into writable */
 257         vma->vm_flags &= ~VM_MAYWRITE;
 258
 259         return remap_pfn_range(vma, vma->vm_start,
 260                                page_to_pfn(status),
 261                                size, vma->vm_page_prot);
 262 }
 263
 264 static const struct file_operations sel_handle_status_ops = {
 265         .open           = sel_open_handle_status,
 266         .read           = sel_read_handle_status,
 267         .mmap           = sel_mmap_handle_status,
 268         .llseek         = generic_file_llseek,
 269 };
 270
 271 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 272 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 273                                  size_t count, loff_t *ppos)
 274
 275 {
 276         char *page = NULL;
 277         ssize_t length;
 278         int new_value;
 279
 280         length = -ENOMEM;
 281         if (count >= PAGE_SIZE)
 282                 goto out;
 283
 284         /* No partial writes. */
 285         length = -EINVAL;
 286         if (*ppos != 0)
 287                 goto out;
 288
 289         length = -ENOMEM;
 290         page = (char *)get_zeroed_page(GFP_KERNEL);
 291         if (!page)
 292                 goto out;
 293
 294         length = -EFAULT;
 295         if (copy_from_user(page, buf, count))
 296                 goto out;
 297
 298         length = -EINVAL;
 299         if (sscanf(page, "%d", &new_value) != 1)
 300                 goto out;
 301
 302         if (new_value) {
 303                 length = selinux_disable();
 304                 if (length)
 305                         goto out;
 306                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 307                         "selinux=0 auid=%u ses=%u",
 308                         audit_get_loginuid(current),
 309                         audit_get_sessionid(current));
 310         }
 311
 312         length = count;
 313 out:
 314         free_page((unsigned long) page);
 315         return length;
 316 }
 317 #else
 318 #define sel_write_disable NULL
 319 #endif
 320
 321 static const struct file_operations sel_disable_ops = {
 322         .write          = sel_write_disable,
 323         .llseek         = generic_file_llseek,
 324 };
 325
 326 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 327                                    size_t count, loff_t *ppos)
 328 {
 329         char tmpbuf[TMPBUFLEN];
 330         ssize_t length;
 331
 332         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 333         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 334 }
 335
 336 static const struct file_operations sel_policyvers_ops = {
 337         .read           = sel_read_policyvers,
 338         .llseek         = generic_file_llseek,
 339 };
 340
 341 /* declaration for sel_write_load */
 342 static int sel_make_bools(void);
 343 static int sel_make_classes(void);
 344 static int sel_make_policycap(void);
 345
 346 /* declaration for sel_make_class_dirs */
 347 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
 348                         unsigned long *ino);
 349
 350 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 351                                 size_t count, loff_t *ppos)
 352 {
 353         char tmpbuf[TMPBUFLEN];
 354         ssize_t length;
 355
 356         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 357                            security_mls_enabled());
 358         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 359 }
 360
 361 static const struct file_operations sel_mls_ops = {
 362         .read           = sel_read_mls,
 363         .llseek         = generic_file_llseek,
 364 };
 365
 366 struct policy_load_memory {
 367         size_t len;
 368         void *data;
 369 };
 370
 371 static int sel_open_policy(struct inode *inode, struct file *filp)
 372 {
 373         struct policy_load_memory *plm = NULL;
 374         int rc;
 375
 376         BUG_ON(filp->private_data);
 377
 378         mutex_lock(&sel_mutex);
 379
 380         rc = task_has_security(current, SECURITY__READ_POLICY);
 381         if (rc)
 382                 goto err;
 383
 384         rc = -EBUSY;
 385         if (policy_opened)
 386                 goto err;
 387
 388         rc = -ENOMEM;
 389         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 390         if (!plm)
 391                 goto err;
 392
 393         if (i_size_read(inode) != security_policydb_len()) {
 394                 mutex_lock(&inode->i_mutex);
 395                 i_size_write(inode, security_policydb_len());
 396                 mutex_unlock(&inode->i_mutex);
 397         }
 398
 399         rc = security_read_policy(&plm->data, &plm->len);
 400         if (rc)
 401                 goto err;
 402
 403         policy_opened = 1;
 404
 405         filp->private_data = plm;
 406
 407         mutex_unlock(&sel_mutex);
 408
 409         return 0;
 410 err:
 411         mutex_unlock(&sel_mutex);
 412
 413         if (plm)
 414                 vfree(plm->data);
 415         kfree(plm);
 416         return rc;
 417 }
 418
 419 static int sel_release_policy(struct inode *inode, struct file *filp)
 420 {
 421         struct policy_load_memory *plm = filp->private_data;
 422
 423         BUG_ON(!plm);
 424
 425         policy_opened = 0;
 426
 427         vfree(plm->data);
 428         kfree(plm);
 429
 430         return 0;
 431 }
 432
 433 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 434                                size_t count, loff_t *ppos)
 435 {
 436         struct policy_load_memory *plm = filp->private_data;
 437         int ret;
 438
 439         mutex_lock(&sel_mutex);
 440
 441         ret = task_has_security(current, SECURITY__READ_POLICY);
 442         if (ret)
 443                 goto out;
 444
 445         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 446 out:
 447         mutex_unlock(&sel_mutex);
 448         return ret;
 449 }
 450
 451 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 452                                  struct vm_fault *vmf)
 453 {
 454         struct policy_load_memory *plm = vma->vm_file->private_data;
 455         unsigned long offset;
 456         struct page *page;
 457
 458         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 459                 return VM_FAULT_SIGBUS;
 460
 461         offset = vmf->pgoff << PAGE_SHIFT;
 462         if (offset >= roundup(plm->len, PAGE_SIZE))
 463                 return VM_FAULT_SIGBUS;
 464
 465         page = vmalloc_to_page(plm->data + offset);
 466         get_page(page);
 467
 468         vmf->page = page;
 469
 470         return 0;
 471 }
 472
 473 static struct vm_operations_struct sel_mmap_policy_ops = {
 474         .fault = sel_mmap_policy_fault,
 475         .page_mkwrite = sel_mmap_policy_fault,
 476 };
 477
 478 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 479 {
 480         if (vma->vm_flags & VM_SHARED) {
 481                 /* do not allow mprotect to make mapping writable */
 482                 vma->vm_flags &= ~VM_MAYWRITE;
 483
 484                 if (vma->vm_flags & VM_WRITE)
 485                         return -EACCES;
 486         }
 487
 488         vma->vm_flags |= VM_RESERVED;
 489         vma->vm_ops = &sel_mmap_policy_ops;
 490
 491         return 0;
 492 }
 493
 494 static const struct file_operations sel_policy_ops = {
 495         .open           = sel_open_policy,
 496         .read           = sel_read_policy,
 497         .mmap           = sel_mmap_policy,
 498         .release        = sel_release_policy,
 499 };
 500
 501 static ssize_t sel_write_load(struct file *file, const char __user *buf,
 502                               size_t count, loff_t *ppos)
 503
 504 {
 505         ssize_t length;
 506         void *data = NULL;
 507
 508         mutex_lock(&sel_mutex);
 509
 510         length = task_has_security(current, SECURITY__LOAD_POLICY);
 511         if (length)
 512                 goto out;
 513
 514         /* No partial writes. */
 515         length = -EINVAL;
 516         if (*ppos != 0)
 517                 goto out;
 518
 519         length = -EFBIG;
 520         if (count > 64 * 1024 * 1024)
 521                 goto out;
 522
 523         length = -ENOMEM;
 524         data = vmalloc(count);
 525         if (!data)
 526                 goto out;
 527
 528         length = -EFAULT;
 529         if (copy_from_user(data, buf, count) != 0)
 530                 goto out;
 531
 532         length = security_load_policy(data, count);
 533         if (length)
 534                 goto out;
 535
 536         length = sel_make_bools();
 537         if (length)
 538                 goto out1;
 539
 540         length = sel_make_classes();
 541         if (length)
 542                 goto out1;
 543
 544         length = sel_make_policycap();
 545         if (length)
 546                 goto out1;
 547
 548         length = count;
 549
 550 out1:
 551         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 552                 "policy loaded auid=%u ses=%u",
 553                 audit_get_loginuid(current),
 554                 audit_get_sessionid(current));
 555 out:
 556         mutex_unlock(&sel_mutex);
 557         vfree(data);
 558         return length;
 559 }
 560
 561 static const struct file_operations sel_load_ops = {
 562         .write          = sel_write_load,
 563         .llseek         = generic_file_llseek,
 564 };
 565
 566 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 567 {
 568         char *canon = NULL;
 569         u32 sid, len;
 570         ssize_t length;
 571
 572         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 573         if (length)
 574                 goto out;
 575
 576         length = security_context_to_sid(buf, size, &sid);
 577         if (length)
 578                 goto out;
 579
 580         length = security_sid_to_context(sid, &canon, &len);
 581         if (length)
 582                 goto out;
 583
 584         length = -ERANGE;
 585         if (len > SIMPLE_TRANSACTION_LIMIT) {
 586                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 587                         "payload max\n", __func__, len);
 588                 goto out;
 589         }
 590
 591         memcpy(buf, canon, len);
 592         length = len;
 593 out:
 594         kfree(canon);
 595         return length;
 596 }
 597
 598 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 599                                      size_t count, loff_t *ppos)
 600 {
 601         char tmpbuf[TMPBUFLEN];
 602         ssize_t length;
 603
 604         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 605         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 606 }
 607
 608 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 609                                       size_t count, loff_t *ppos)
 610 {
 611         char *page = NULL;
 612         ssize_t length;
 613         unsigned int new_value;
 614
 615         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 616         if (length)
 617                 goto out;
 618
 619         length = -ENOMEM;
 620         if (count >= PAGE_SIZE)
 621                 goto out;
 622
 623         /* No partial writes. */
 624         length = -EINVAL;
 625         if (*ppos != 0)
 626                 goto out;
 627
 628         length = -ENOMEM;
 629         page = (char *)get_zeroed_page(GFP_KERNEL);
 630         if (!page)
 631                 goto out;
 632
 633         length = -EFAULT;
 634         if (copy_from_user(page, buf, count))
 635                 goto out;
 636
 637         length = -EINVAL;
 638         if (sscanf(page, "%u", &new_value) != 1)
 639                 goto out;
 640
 641         selinux_checkreqprot = new_value ? 1 : 0;
 642         length = count;
 643 out:
 644         free_page((unsigned long) page);
 645         return length;
 646 }
 647 static const struct file_operations sel_checkreqprot_ops = {
 648         .read           = sel_read_checkreqprot,
 649         .write          = sel_write_checkreqprot,
 650         .llseek         = generic_file_llseek,
 651 };
 652
 653 /*
 654  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 655  */
 656 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 657 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 658 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 659 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 660 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 661
 662 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 663         [SEL_ACCESS] = sel_write_access,
 664         [SEL_CREATE] = sel_write_create,
 665         [SEL_RELABEL] = sel_write_relabel,
 666         [SEL_USER] = sel_write_user,
 667         [SEL_MEMBER] = sel_write_member,
 668         [SEL_CONTEXT] = sel_write_context,
 669 };
 670
 671 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 672 {
 673         ino_t ino = file->f_path.dentry->d_inode->i_ino;
 674         char *data;
 675         ssize_t rv;
 676
 677         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 678                 return -EINVAL;
 679
 680         data = simple_transaction_get(file, buf, size);
 681         if (IS_ERR(data))
 682                 return PTR_ERR(data);
 683
 684         rv = write_op[ino](file, data, size);
 685         if (rv > 0) {
 686                 simple_transaction_set(file, rv);
 687                 rv = size;
 688         }
 689         return rv;
 690 }
 691
 692 static const struct file_operations transaction_ops = {
 693         .write          = selinux_transaction_write,
 694         .read           = simple_transaction_read,
 695         .release        = simple_transaction_release,
 696         .llseek         = generic_file_llseek,
 697 };
 698
 699 /*
 700  * payload - write methods
 701  * If the method has a response, the response should be put in buf,
 702  * and the length returned.  Otherwise return 0 or and -error.
 703  */
 704
 705 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 706 {
 707         char *scon = NULL, *tcon = NULL;
 708         u32 ssid, tsid;
 709         u16 tclass;
 710         struct av_decision avd;
 711         ssize_t length;
 712
 713         length = task_has_security(current, SECURITY__COMPUTE_AV);
 714         if (length)
 715                 goto out;
 716
 717         length = -ENOMEM;
 718         scon = kzalloc(size + 1, GFP_KERNEL);
 719         if (!scon)
 720                 goto out;
 721
 722         length = -ENOMEM;
 723         tcon = kzalloc(size + 1, GFP_KERNEL);
 724         if (!tcon)
 725                 goto out;
 726
 727         length = -EINVAL;
 728         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 729                 goto out;
 730
 731         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 732         if (length)
 733                 goto out;
 734
 735         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 736         if (length)
 737                 goto out;
 738
 739         security_compute_av_user(ssid, tsid, tclass, &avd);
 740
 741         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 742                           "%x %x %x %x %u %x",
 743                           avd.allowed, 0xffffffff,
 744                           avd.auditallow, avd.auditdeny,
 745                           avd.seqno, avd.flags);
 746 out:
 747         kfree(tcon);
 748         kfree(scon);
 749         return length;
 750 }
 751
 752 static inline int hexcode_to_int(int code) {
 753         if (code == '\0' || !isxdigit(code))
 754                 return -1;
 755         if (isdigit(code))
 756                 return code - '0';
 757         return tolower(code) - 'a' + 10;
 758 }
 759
 760 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 761 {
 762         char *scon = NULL, *tcon = NULL;
 763         char *namebuf = NULL, *objname = NULL;
 764         u32 ssid, tsid, newsid;
 765         u16 tclass;
 766         ssize_t length;
 767         char *newcon = NULL;
 768         u32 len;
 769         int nargs;
 770
 771         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 772         if (length)
 773                 goto out;
 774
 775         length = -ENOMEM;
 776         scon = kzalloc(size + 1, GFP_KERNEL);
 777         if (!scon)
 778                 goto out;
 779
 780         length = -ENOMEM;
 781         tcon = kzalloc(size + 1, GFP_KERNEL);
 782         if (!tcon)
 783                 goto out;
 784
 785         length = -ENOMEM;
 786         namebuf = kzalloc(size + 1, GFP_KERNEL);
 787         if (!namebuf)
 788                 goto out;
 789
 790         length = -EINVAL;
 791         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 792         if (nargs < 3 || nargs > 4)
 793                 goto out;
 794         if (nargs == 4) {
 795                 /*
 796                  * If and when the name of new object to be queried contains
 797                  * either whitespace or multibyte characters, they shall be
 798                  * encoded based on the percentage-encoding rule.
 799                  * If not encoded, the sscanf logic picks up only left-half
 800                  * of the supplied name; splitted by a whitespace unexpectedly.
 801                  */
 802                 char   *r, *w;
 803                 int     c1, c2;
 804
 805                 r = w = namebuf;
 806                 do {
 807                         c1 = *r++;
 808                         if (c1 == '+')
 809                                 c1 = ' ';
 810                         else if (c1 == '%') {
 811                                 if ((c1 = hexcode_to_int(*r++)) < 0)
 812                                         goto out;
 813                                 if ((c2 = hexcode_to_int(*r++)) < 0)
 814                                         goto out;
 815                                 c1 = (c1 << 4) | c2;
 816                         }
 817                         *w++ = c1;
 818                 } while (c1 != '\0');
 819
 820                 objname = namebuf;
 821         }
 822
 823         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 824         if (length)
 825                 goto out;
 826
 827         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 828         if (length)
 829                 goto out;
 830
 831         length = security_transition_sid_user(ssid, tsid, tclass,
 832                                               objname, &newsid);
 833         if (length)
 834                 goto out;
 835
 836         length = security_sid_to_context(newsid, &newcon, &len);
 837         if (length)
 838                 goto out;
 839
 840         length = -ERANGE;
 841         if (len > SIMPLE_TRANSACTION_LIMIT) {
 842                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 843                         "payload max\n", __func__, len);
 844                 goto out;
 845         }
 846
 847         memcpy(buf, newcon, len);
 848         length = len;
 849 out:
 850         kfree(newcon);
 851         kfree(namebuf);
 852         kfree(tcon);
 853         kfree(scon);
 854         return length;
 855 }
 856
 857 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 858 {
 859         char *scon = NULL, *tcon = NULL;
 860         u32 ssid, tsid, newsid;
 861         u16 tclass;
 862         ssize_t length;
 863         char *newcon = NULL;
 864         u32 len;
 865
 866         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 867         if (length)
 868                 goto out;
 869
 870         length = -ENOMEM;
 871         scon = kzalloc(size + 1, GFP_KERNEL);
 872         if (!scon)
 873                 goto out;
 874
 875         length = -ENOMEM;
 876         tcon = kzalloc(size + 1, GFP_KERNEL);
 877         if (!tcon)
 878                 goto out;
 879
 880         length = -EINVAL;
 881         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 882                 goto out;
 883
 884         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 885         if (length)
 886                 goto out;
 887
 888         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 889         if (length)
 890                 goto out;
 891
 892         length = security_change_sid(ssid, tsid, tclass, &newsid);
 893         if (length)
 894                 goto out;
 895
 896         length = security_sid_to_context(newsid, &newcon, &len);
 897         if (length)
 898                 goto out;
 899
 900         length = -ERANGE;
 901         if (len > SIMPLE_TRANSACTION_LIMIT)
 902                 goto out;
 903
 904         memcpy(buf, newcon, len);
 905         length = len;
 906 out:
 907         kfree(newcon);
 908         kfree(tcon);
 909         kfree(scon);
 910         return length;
 911 }
 912
 913 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 914 {
 915         char *con = NULL, *user = NULL, *ptr;
 916         u32 sid, *sids = NULL;
 917         ssize_t length;
 918         char *newcon;
 919         int i, rc;
 920         u32 len, nsids;
 921
 922         length = task_has_security(current, SECURITY__COMPUTE_USER);
 923         if (length)
 924                 goto out;
 925
 926         length = -ENOMEM;
 927         con = kzalloc(size + 1, GFP_KERNEL);
 928         if (!con)
 929                 goto out;
 930
 931         length = -ENOMEM;
 932         user = kzalloc(size + 1, GFP_KERNEL);
 933         if (!user)
 934                 goto out;
 935
 936         length = -EINVAL;
 937         if (sscanf(buf, "%s %s", con, user) != 2)
 938                 goto out;
 939
 940         length = security_context_to_sid(con, strlen(con) + 1, &sid);
 941         if (length)
 942                 goto out;
 943
 944         length = security_get_user_sids(sid, user, &sids, &nsids);
 945         if (length)
 946                 goto out;
 947
 948         length = sprintf(buf, "%u", nsids) + 1;
 949         ptr = buf + length;
 950         for (i = 0; i < nsids; i++) {
 951                 rc = security_sid_to_context(sids[i], &newcon, &len);
 952                 if (rc) {
 953                         length = rc;
 954                         goto out;
 955                 }
 956                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 957                         kfree(newcon);
 958                         length = -ERANGE;
 959                         goto out;
 960                 }
 961                 memcpy(ptr, newcon, len);
 962                 kfree(newcon);
 963                 ptr += len;
 964                 length += len;
 965         }
 966 out:
 967         kfree(sids);
 968         kfree(user);
 969         kfree(con);
 970         return length;
 971 }
 972
 973 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 974 {
 975         char *scon = NULL, *tcon = NULL;
 976         u32 ssid, tsid, newsid;
 977         u16 tclass;
 978         ssize_t length;
 979         char *newcon = NULL;
 980         u32 len;
 981
 982         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 983         if (length)
 984                 goto out;
 985
 986         length = -ENOMEM;
 987         scon = kzalloc(size + 1, GFP_KERNEL);
 988         if (!scon)
 989                 goto out;
 990
 991         length = -ENOMEM;
 992         tcon = kzalloc(size + 1, GFP_KERNEL);
 993         if (!tcon)
 994                 goto out;
 995
 996         length = -EINVAL;
 997         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 998                 goto out;
 999
1000         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
1001         if (length)
1002                 goto out;
1003
1004         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1005         if (length)
1006                 goto out;
1007
1008         length = security_member_sid(ssid, tsid, tclass, &newsid);
1009         if (length)
1010                 goto out;
1011
1012         length = security_sid_to_context(newsid, &newcon, &len);
1013         if (length)
1014                 goto out;
1015
1016         length = -ERANGE;
1017         if (len > SIMPLE_TRANSACTION_LIMIT) {
1018                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1019                         "payload max\n", __func__, len);
1020                 goto out;
1021         }
1022
1023         memcpy(buf, newcon, len);
1024         length = len;
1025 out:
1026         kfree(newcon);
1027         kfree(tcon);
1028         kfree(scon);
1029         return length;
1030 }
1031
1032 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1033 {
1034         struct inode *ret = new_inode(sb);
1035
1036         if (ret) {
1037                 ret->i_mode = mode;
1038                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1039         }
1040         return ret;
1041 }
1042
1043 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1044                              size_t count, loff_t *ppos)
1045 {
1046         char *page = NULL;
1047         ssize_t length;
1048         ssize_t ret;
1049         int cur_enforcing;
1050         struct inode *inode = filep->f_path.dentry->d_inode;
1051         unsigned index = inode->i_ino & SEL_INO_MASK;
1052         const char *name = filep->f_path.dentry->d_name.name;
1053
1054         mutex_lock(&sel_mutex);
1055
1056         ret = -EINVAL;
1057         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1058                 goto out;
1059
1060         ret = -ENOMEM;
1061         page = (char *)get_zeroed_page(GFP_KERNEL);
1062         if (!page)
1063                 goto out;
1064
1065         cur_enforcing = security_get_bool_value(index);
1066         if (cur_enforcing < 0) {
1067                 ret = cur_enforcing;
1068                 goto out;
1069         }
1070         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1071                           bool_pending_values[index]);
1072         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1073 out:
1074         mutex_unlock(&sel_mutex);
1075         free_page((unsigned long)page);
1076         return ret;
1077 }
1078
1079 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1080                               size_t count, loff_t *ppos)
1081 {
1082         char *page = NULL;
1083         ssize_t length;
1084         int new_value;
1085         struct inode *inode = filep->f_path.dentry->d_inode;
1086         unsigned index = inode->i_ino & SEL_INO_MASK;
1087         const char *name = filep->f_path.dentry->d_name.name;
1088
1089         mutex_lock(&sel_mutex);
1090
1091         length = task_has_security(current, SECURITY__SETBOOL);
1092         if (length)
1093                 goto out;
1094
1095         length = -EINVAL;
1096         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1097                 goto out;
1098
1099         length = -ENOMEM;
1100         if (count >= PAGE_SIZE)
1101                 goto out;
1102
1103         /* No partial writes. */
1104         length = -EINVAL;
1105         if (*ppos != 0)
1106                 goto out;
1107
1108         length = -ENOMEM;
1109         page = (char *)get_zeroed_page(GFP_KERNEL);
1110         if (!page)
1111                 goto out;
1112
1113         length = -EFAULT;
1114         if (copy_from_user(page, buf, count))
1115                 goto out;
1116
1117         length = -EINVAL;
1118         if (sscanf(page, "%d", &new_value) != 1)
1119                 goto out;
1120
1121         if (new_value)
1122                 new_value = 1;
1123
1124         bool_pending_values[index] = new_value;
1125         length = count;
1126
1127 out:
1128         mutex_unlock(&sel_mutex);
1129         free_page((unsigned long) page);
1130         return length;
1131 }
1132
1133 static const struct file_operations sel_bool_ops = {
1134         .read           = sel_read_bool,
1135         .write          = sel_write_bool,
1136         .llseek         = generic_file_llseek,
1137 };
1138
1139 static ssize_t sel_commit_bools_write(struct file *filep,
1140                                       const char __user *buf,
1141                                       size_t count, loff_t *ppos)
1142 {
1143         char *page = NULL;
1144         ssize_t length;
1145         int new_value;
1146
1147         mutex_lock(&sel_mutex);
1148
1149         length = task_has_security(current, SECURITY__SETBOOL);
1150         if (length)
1151                 goto out;
1152
1153         length = -ENOMEM;
1154         if (count >= PAGE_SIZE)
1155                 goto out;
1156
1157         /* No partial writes. */
1158         length = -EINVAL;
1159         if (*ppos != 0)
1160                 goto out;
1161
1162         length = -ENOMEM;
1163         page = (char *)get_zeroed_page(GFP_KERNEL);
1164         if (!page)
1165                 goto out;
1166
1167         length = -EFAULT;
1168         if (copy_from_user(page, buf, count))
1169                 goto out;
1170
1171         length = -EINVAL;
1172         if (sscanf(page, "%d", &new_value) != 1)
1173                 goto out;
1174
1175         length = 0;
1176         if (new_value && bool_pending_values)
1177                 length = security_set_bools(bool_num, bool_pending_values);
1178
1179         if (!length)
1180                 length = count;
1181
1182 out:
1183         mutex_unlock(&sel_mutex);
1184         free_page((unsigned long) page);
1185         return length;
1186 }
1187
1188 static const struct file_operations sel_commit_bools_ops = {
1189         .write          = sel_commit_bools_write,
1190         .llseek         = generic_file_llseek,
1191 };
1192
1193 static void sel_remove_entries(struct dentry *de)
1194 {
1195         struct list_head *node;
1196
1197         spin_lock(&de->d_lock);
1198         node = de->d_subdirs.next;
1199         while (node != &de->d_subdirs) {
1200                 struct dentry *d = list_entry(node, struct dentry, d_child);
1201
1202                 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1203                 list_del_init(node);
1204
1205                 if (d->d_inode) {
1206                         dget_dlock(d);
1207                         spin_unlock(&de->d_lock);
1208                         spin_unlock(&d->d_lock);
1209                         d_delete(d);
1210                         simple_unlink(de->d_inode, d);
1211                         dput(d);
1212                         spin_lock(&de->d_lock);
1213                 } else
1214                         spin_unlock(&d->d_lock);
1215                 node = de->d_subdirs.next;
1216         }
1217
1218         spin_unlock(&de->d_lock);
1219 }
1220
1221 #define BOOL_DIR_NAME "booleans"
1222
1223 static int sel_make_bools(void)
1224 {
1225         int i, ret;
1226         ssize_t len;
1227         struct dentry *dentry = NULL;
1228         struct dentry *dir = bool_dir;
1229         struct inode *inode = NULL;
1230         struct inode_security_struct *isec;
1231         char **names = NULL, *page;
1232         int num;
1233         int *values = NULL;
1234         u32 sid;
1235
1236         /* remove any existing files */
1237         for (i = 0; i < bool_num; i++)
1238                 kfree(bool_pending_names[i]);
1239         kfree(bool_pending_names);
1240         kfree(bool_pending_values);
1241         bool_num = 0;
1242         bool_pending_names = NULL;
1243         bool_pending_values = NULL;
1244
1245         sel_remove_entries(dir);
1246
1247         ret = -ENOMEM;
1248         page = (char *)get_zeroed_page(GFP_KERNEL);
1249         if (!page)
1250                 goto out;
1251
1252         ret = security_get_bools(&num, &names, &values);
1253         if (ret)
1254                 goto out;
1255
1256         for (i = 0; i < num; i++) {
1257                 ret = -ENOMEM;
1258                 dentry = d_alloc_name(dir, names[i]);
1259                 if (!dentry)
1260                         goto out;
1261
1262                 ret = -ENOMEM;
1263                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1264                 if (!inode)
1265                         goto out;
1266
1267                 ret = -EINVAL;
1268                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1269                 if (len < 0)
1270                         goto out;
1271
1272                 ret = -ENAMETOOLONG;
1273                 if (len >= PAGE_SIZE)
1274                         goto out;
1275
1276                 isec = (struct inode_security_struct *)inode->i_security;
1277                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1278                 if (ret)
1279                         goto out;
1280
1281                 isec->sid = sid;
1282                 isec->initialized = 1;
1283                 inode->i_fop = &sel_bool_ops;
1284                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1285                 d_add(dentry, inode);
1286         }
1287         bool_num = num;
1288         bool_pending_names = names;
1289         bool_pending_values = values;
1290
1291         free_page((unsigned long)page);
1292         return 0;
1293 out:
1294         free_page((unsigned long)page);
1295
1296         if (names) {
1297                 for (i = 0; i < num; i++)
1298                         kfree(names[i]);
1299                 kfree(names);
1300         }
1301         kfree(values);
1302         sel_remove_entries(dir);
1303
1304         return ret;
1305 }
1306
1307 #define NULL_FILE_NAME "null"
1308
1309 struct dentry *selinux_null;
1310
1311 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1312                                             size_t count, loff_t *ppos)
1313 {
1314         char tmpbuf[TMPBUFLEN];
1315         ssize_t length;
1316
1317         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1318         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1319 }
1320
1321 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1322                                              const char __user *buf,
1323                                              size_t count, loff_t *ppos)
1324
1325 {
1326         char *page = NULL;
1327         ssize_t ret;
1328         int new_value;
1329
1330         ret = task_has_security(current, SECURITY__SETSECPARAM);
1331         if (ret)
1332                 goto out;
1333
1334         ret = -ENOMEM;
1335         if (count >= PAGE_SIZE)
1336                 goto out;
1337
1338         /* No partial writes. */
1339         ret = -EINVAL;
1340         if (*ppos != 0)
1341                 goto out;
1342
1343         ret = -ENOMEM;
1344         page = (char *)get_zeroed_page(GFP_KERNEL);
1345         if (!page)
1346                 goto out;
1347
1348         ret = -EFAULT;
1349         if (copy_from_user(page, buf, count))
1350                 goto out;
1351
1352         ret = -EINVAL;
1353         if (sscanf(page, "%u", &new_value) != 1)
1354                 goto out;
1355
1356         avc_cache_threshold = new_value;
1357
1358         ret = count;
1359 out:
1360         free_page((unsigned long)page);
1361         return ret;
1362 }
1363
1364 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1365                                        size_t count, loff_t *ppos)
1366 {
1367         char *page;
1368         ssize_t length;
1369
1370         page = (char *)__get_free_page(GFP_KERNEL);
1371         if (!page)
1372                 return -ENOMEM;
1373
1374         length = avc_get_hash_stats(page);
1375         if (length >= 0)
1376                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1377         free_page((unsigned long)page);
1378
1379         return length;
1380 }
1381
1382 static const struct file_operations sel_avc_cache_threshold_ops = {
1383         .read           = sel_read_avc_cache_threshold,
1384         .write          = sel_write_avc_cache_threshold,
1385         .llseek         = generic_file_llseek,
1386 };
1387
1388 static const struct file_operations sel_avc_hash_stats_ops = {
1389         .read           = sel_read_avc_hash_stats,
1390         .llseek         = generic_file_llseek,
1391 };
1392
1393 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1394 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1395 {
1396         int cpu;
1397
1398         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1399                 if (!cpu_possible(cpu))
1400                         continue;
1401                 *idx = cpu + 1;
1402                 return &per_cpu(avc_cache_stats, cpu);
1403         }
1404         return NULL;
1405 }
1406
1407 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1408 {
1409         loff_t n = *pos - 1;
1410
1411         if (*pos == 0)
1412                 return SEQ_START_TOKEN;
1413
1414         return sel_avc_get_stat_idx(&n);
1415 }
1416
1417 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1418 {
1419         return sel_avc_get_stat_idx(pos);
1420 }
1421
1422 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1423 {
1424         struct avc_cache_stats *st = v;
1425
1426         if (v == SEQ_START_TOKEN)
1427                 seq_printf(seq, "lookups hits misses allocations reclaims "
1428                            "frees\n");
1429         else {
1430                 unsigned int lookups = st->lookups;
1431                 unsigned int misses = st->misses;
1432                 unsigned int hits = lookups - misses;
1433                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1434                            hits, misses, st->allocations,
1435                            st->reclaims, st->frees);
1436         }
1437         return 0;
1438 }
1439
1440 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1441 { }
1442
1443 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1444         .start          = sel_avc_stats_seq_start,
1445         .next           = sel_avc_stats_seq_next,
1446         .show           = sel_avc_stats_seq_show,
1447         .stop           = sel_avc_stats_seq_stop,
1448 };
1449
1450 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1451 {
1452         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1453 }
1454
1455 static const struct file_operations sel_avc_cache_stats_ops = {
1456         .open           = sel_open_avc_cache_stats,
1457         .read           = seq_read,
1458         .llseek         = seq_lseek,
1459         .release        = seq_release,
1460 };
1461 #endif
1462
1463 static int sel_make_avc_files(struct dentry *dir)
1464 {
1465         int i;
1466         static struct tree_descr files[] = {
1467                 { "cache_threshold",
1468                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1469                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1470 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1471                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1472 #endif
1473         };
1474
1475         for (i = 0; i < ARRAY_SIZE(files); i++) {
1476                 struct inode *inode;
1477                 struct dentry *dentry;
1478
1479                 dentry = d_alloc_name(dir, files[i].name);
1480                 if (!dentry)
1481                         return -ENOMEM;
1482
1483                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1484                 if (!inode)
1485                         return -ENOMEM;
1486
1487                 inode->i_fop = files[i].ops;
1488                 inode->i_ino = ++sel_last_ino;
1489                 d_add(dentry, inode);
1490         }
1491
1492         return 0;
1493 }
1494
1495 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1496                                 size_t count, loff_t *ppos)
1497 {
1498         struct inode *inode;
1499         char *con;
1500         u32 sid, len;
1501         ssize_t ret;
1502
1503         inode = file->f_path.dentry->d_inode;
1504         sid = inode->i_ino&SEL_INO_MASK;
1505         ret = security_sid_to_context(sid, &con, &len);
1506         if (ret)
1507                 return ret;
1508
1509         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1510         kfree(con);
1511         return ret;
1512 }
1513
1514 static const struct file_operations sel_initcon_ops = {
1515         .read           = sel_read_initcon,
1516         .llseek         = generic_file_llseek,
1517 };
1518
1519 static int sel_make_initcon_files(struct dentry *dir)
1520 {
1521         int i;
1522
1523         for (i = 1; i <= SECINITSID_NUM; i++) {
1524                 struct inode *inode;
1525                 struct dentry *dentry;
1526                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1527                 if (!dentry)
1528                         return -ENOMEM;
1529
1530                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1531                 if (!inode)
1532                         return -ENOMEM;
1533
1534                 inode->i_fop = &sel_initcon_ops;
1535                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1536                 d_add(dentry, inode);
1537         }
1538
1539         return 0;
1540 }
1541
1542 static inline unsigned int sel_div(unsigned long a, unsigned long b)
1543 {
1544         return a / b - (a % b < 0);
1545 }
1546
1547 static inline unsigned long sel_class_to_ino(u16 class)
1548 {
1549         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1550 }
1551
1552 static inline u16 sel_ino_to_class(unsigned long ino)
1553 {
1554         return sel_div(ino & SEL_INO_MASK, SEL_VEC_MAX + 1);
1555 }
1556
1557 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1558 {
1559         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1560 }
1561
1562 static inline u32 sel_ino_to_perm(unsigned long ino)
1563 {
1564         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1565 }
1566
1567 static ssize_t sel_read_class(struct file *file, char __user *buf,
1568                                 size_t count, loff_t *ppos)
1569 {
1570         ssize_t rc, len;
1571         char *page;
1572         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1573
1574         page = (char *)__get_free_page(GFP_KERNEL);
1575         if (!page)
1576                 return -ENOMEM;
1577
1578         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
1579         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1580         free_page((unsigned long)page);
1581
1582         return rc;
1583 }
1584
1585 static const struct file_operations sel_class_ops = {
1586         .read           = sel_read_class,
1587         .llseek         = generic_file_llseek,
1588 };
1589
1590 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1591                                 size_t count, loff_t *ppos)
1592 {
1593         ssize_t rc, len;
1594         char *page;
1595         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1596
1597         page = (char *)__get_free_page(GFP_KERNEL);
1598         if (!page)
1599                 return -ENOMEM;
1600
1601         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
1602         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1603         free_page((unsigned long)page);
1604
1605         return rc;
1606 }
1607
1608 static const struct file_operations sel_perm_ops = {
1609         .read           = sel_read_perm,
1610         .llseek         = generic_file_llseek,
1611 };
1612
1613 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1614                                   size_t count, loff_t *ppos)
1615 {
1616         int value;
1617         char tmpbuf[TMPBUFLEN];
1618         ssize_t length;
1619         unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1620
1621         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1622         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1623
1624         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1625 }
1626
1627 static const struct file_operations sel_policycap_ops = {
1628         .read           = sel_read_policycap,
1629         .llseek         = generic_file_llseek,
1630 };
1631
1632 static int sel_make_perm_files(char *objclass, int classvalue,
1633                                 struct dentry *dir)
1634 {
1635         int i, rc, nperms;
1636         char **perms;
1637
1638         rc = security_get_permissions(objclass, &perms, &nperms);
1639         if (rc)
1640                 return rc;
1641
1642         for (i = 0; i < nperms; i++) {
1643                 struct inode *inode;
1644                 struct dentry *dentry;
1645
1646                 rc = -ENOMEM;
1647                 dentry = d_alloc_name(dir, perms[i]);
1648                 if (!dentry)
1649                         goto out;
1650
1651                 rc = -ENOMEM;
1652                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1653                 if (!inode)
1654                         goto out;
1655
1656                 inode->i_fop = &sel_perm_ops;
1657                 /* i+1 since perm values are 1-indexed */
1658                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1659                 d_add(dentry, inode);
1660         }
1661         rc = 0;
1662 out:
1663         for (i = 0; i < nperms; i++)
1664                 kfree(perms[i]);
1665         kfree(perms);
1666         return rc;
1667 }
1668
1669 static int sel_make_class_dir_entries(char *classname, int index,
1670                                         struct dentry *dir)
1671 {
1672         struct dentry *dentry = NULL;
1673         struct inode *inode = NULL;
1674         int rc;
1675
1676         dentry = d_alloc_name(dir, "index");
1677         if (!dentry)
1678                 return -ENOMEM;
1679
1680         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1681         if (!inode)
1682                 return -ENOMEM;
1683
1684         inode->i_fop = &sel_class_ops;
1685         inode->i_ino = sel_class_to_ino(index);
1686         d_add(dentry, inode);
1687
1688         dentry = d_alloc_name(dir, "perms");
1689         if (!dentry)
1690                 return -ENOMEM;
1691
1692         rc = sel_make_dir(dir->d_inode, dentry, &last_class_ino);
1693         if (rc)
1694                 return rc;
1695
1696         rc = sel_make_perm_files(classname, index, dentry);
1697
1698         return rc;
1699 }
1700
1701 static void sel_remove_classes(void)
1702 {
1703         struct list_head *class_node;
1704
1705         list_for_each(class_node, &class_dir->d_subdirs) {
1706                 struct dentry *class_subdir = list_entry(class_node,
1707                                         struct dentry, d_child);
1708                 struct list_head *class_subdir_node;
1709
1710                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1711                         struct dentry *d = list_entry(class_subdir_node,
1712                                                 struct dentry, d_child);
1713
1714                         if (d->d_inode)
1715                                 if (d->d_inode->i_mode & S_IFDIR)
1716                                         sel_remove_entries(d);
1717                 }
1718
1719                 sel_remove_entries(class_subdir);
1720         }
1721
1722         sel_remove_entries(class_dir);
1723 }
1724
1725 static int sel_make_classes(void)
1726 {
1727         int rc, nclasses, i;
1728         char **classes;
1729
1730         /* delete any existing entries */
1731         sel_remove_classes();
1732
1733         rc = security_get_classes(&classes, &nclasses);
1734         if (rc)
1735                 return rc;
1736
1737         /* +2 since classes are 1-indexed */
1738         last_class_ino = sel_class_to_ino(nclasses + 2);
1739
1740         for (i = 0; i < nclasses; i++) {
1741                 struct dentry *class_name_dir;
1742
1743                 rc = -ENOMEM;
1744                 class_name_dir = d_alloc_name(class_dir, classes[i]);
1745                 if (!class_name_dir)
1746                         goto out;
1747
1748                 rc = sel_make_dir(class_dir->d_inode, class_name_dir,
1749                                 &last_class_ino);
1750                 if (rc)
1751                         goto out;
1752
1753                 /* i+1 since class values are 1-indexed */
1754                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1755                                 class_name_dir);
1756                 if (rc)
1757                         goto out;
1758         }
1759         rc = 0;
1760 out:
1761         for (i = 0; i < nclasses; i++)
1762                 kfree(classes[i]);
1763         kfree(classes);
1764         return rc;
1765 }
1766
1767 static int sel_make_policycap(void)
1768 {
1769         unsigned int iter;
1770         struct dentry *dentry = NULL;
1771         struct inode *inode = NULL;
1772
1773         sel_remove_entries(policycap_dir);
1774
1775         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1776                 if (iter < ARRAY_SIZE(policycap_names))
1777                         dentry = d_alloc_name(policycap_dir,
1778                                               policycap_names[iter]);
1779                 else
1780                         dentry = d_alloc_name(policycap_dir, "unknown");
1781
1782                 if (dentry == NULL)
1783                         return -ENOMEM;
1784
1785                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1786                 if (inode == NULL)
1787                         return -ENOMEM;
1788
1789                 inode->i_fop = &sel_policycap_ops;
1790                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1791                 d_add(dentry, inode);
1792         }
1793
1794         return 0;
1795 }
1796
1797 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
1798                         unsigned long *ino)
1799 {
1800         struct inode *inode;
1801
1802         inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1803         if (!inode)
1804                 return -ENOMEM;
1805
1806         inode->i_op = &simple_dir_inode_operations;
1807         inode->i_fop = &simple_dir_operations;
1808         inode->i_ino = ++(*ino);
1809         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1810         inc_nlink(inode);
1811         d_add(dentry, inode);
1812         /* bump link count on parent directory, too */
1813         inc_nlink(dir);
1814
1815         return 0;
1816 }
1817
1818 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1819 {
1820         int ret;
1821         struct dentry *dentry;
1822         struct inode *inode, *root_inode;
1823         struct inode_security_struct *isec;
1824
1825         static struct tree_descr selinux_files[] = {
1826                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1827                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1828                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1829                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1830                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1831                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1832                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1833                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1834                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1835                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1836                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1837                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1838                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1839                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1840                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1841                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1842                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUSR},
1843                 /* last one */ {""}
1844         };
1845         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1846         if (ret)
1847                 goto err;
1848
1849         root_inode = sb->s_root->d_inode;
1850
1851         ret = -ENOMEM;
1852         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1853         if (!dentry)
1854                 goto err;
1855
1856         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1857         if (ret)
1858                 goto err;
1859
1860         bool_dir = dentry;
1861
1862         ret = -ENOMEM;
1863         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1864         if (!dentry)
1865                 goto err;
1866
1867         ret = -ENOMEM;
1868         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1869         if (!inode)
1870                 goto err;
1871
1872         inode->i_ino = ++sel_last_ino;
1873         isec = (struct inode_security_struct *)inode->i_security;
1874         isec->sid = SECINITSID_DEVNULL;
1875         isec->sclass = SECCLASS_CHR_FILE;
1876         isec->initialized = 1;
1877
1878         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1879         d_add(dentry, inode);
1880         selinux_null = dentry;
1881
1882         ret = -ENOMEM;
1883         dentry = d_alloc_name(sb->s_root, "avc");
1884         if (!dentry)
1885                 goto err;
1886
1887         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1888         if (ret)
1889                 goto err;
1890
1891         ret = sel_make_avc_files(dentry);
1892         if (ret)
1893                 goto err;
1894
1895         ret = -ENOMEM;
1896         dentry = d_alloc_name(sb->s_root, "initial_contexts");
1897         if (!dentry)
1898                 goto err;
1899
1900         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1901         if (ret)
1902                 goto err;
1903
1904         ret = sel_make_initcon_files(dentry);
1905         if (ret)
1906                 goto err;
1907
1908         ret = -ENOMEM;
1909         dentry = d_alloc_name(sb->s_root, "class");
1910         if (!dentry)
1911                 goto err;
1912
1913         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1914         if (ret)
1915                 goto err;
1916
1917         class_dir = dentry;
1918
1919         ret = -ENOMEM;
1920         dentry = d_alloc_name(sb->s_root, "policy_capabilities");
1921         if (!dentry)
1922                 goto err;
1923
1924         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1925         if (ret)
1926                 goto err;
1927
1928         policycap_dir = dentry;
1929
1930         return 0;
1931 err:
1932         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1933                 __func__);
1934         return ret;
1935 }
1936
1937 static struct dentry *sel_mount(struct file_system_type *fs_type,
1938                       int flags, const char *dev_name, void *data)
1939 {
1940         return mount_single(fs_type, flags, data, sel_fill_super);
1941 }
1942
1943 static struct file_system_type sel_fs_type = {
1944         .name           = "selinuxfs",
1945         .mount          = sel_mount,
1946         .kill_sb        = kill_litter_super,
1947 };
1948
1949 struct vfsmount *selinuxfs_mount;
1950 static struct kobject *selinuxfs_kobj;
1951
1952 static int __init init_sel_fs(void)
1953 {
1954         int err;
1955
1956         if (!selinux_enabled)
1957                 return 0;
1958
1959         selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1960         if (!selinuxfs_kobj)
1961                 return -ENOMEM;
1962
1963         err = register_filesystem(&sel_fs_type);
1964         if (err) {
1965                 kobject_put(selinuxfs_kobj);
1966                 return err;
1967         }
1968
1969         selinuxfs_mount = kern_mount(&sel_fs_type);
1970         if (IS_ERR(selinuxfs_mount)) {
1971                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1972                 err = PTR_ERR(selinuxfs_mount);
1973                 selinuxfs_mount = NULL;
1974         }
1975
1976         return err;
1977 }
1978
1979 __initcall(init_sel_fs);
1980
1981 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1982 void exit_sel_fs(void)
1983 {
1984         kobject_put(selinuxfs_kobj);
1985         kern_unmount(selinuxfs_mount);
1986         unregister_filesystem(&sel_fs_type);
1987 }
1988 #endif