security/selinux/selinuxfs.c

   1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
   2  *
   3  *      Added conditional policy language extensions
   4  *
   5  *  Updated: Hewlett-Packard <paul.moore@hp.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
  32 /* selinuxfs pseudo filesystem for exporting the security policy API.
  33    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  34
  35 #include "flask.h"
  36 #include "avc.h"
  37 #include "avc_ss.h"
  38 #include "security.h"
  39 #include "objsec.h"
  40 #include "conditional.h"
  41
  42 /* Policy capability filenames */
  43 static char *policycap_names[] = {
  44         "network_peer_controls",
  45         "open_perms"
  46 };
  47
  48 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  49
  50 static int __init checkreqprot_setup(char *str)
  51 {
  52         unsigned long checkreqprot;
  53         if (!strict_strtoul(str, 0, &checkreqprot))
  54                 selinux_checkreqprot = checkreqprot ? 1 : 0;
  55         return 1;
  56 }
  57 __setup("checkreqprot=", checkreqprot_setup);
  58
  59 static DEFINE_MUTEX(sel_mutex);
  60
  61 /* global data for booleans */
  62 static struct dentry *bool_dir;
  63 static int bool_num;
  64 static char **bool_pending_names;
  65 static int *bool_pending_values;
  66
  67 /* global data for classes */
  68 static struct dentry *class_dir;
  69 static unsigned long last_class_ino;
  70
  71 static char policy_opened;
  72
  73 /* global data for policy capabilities */
  74 static struct dentry *policycap_dir;
  75
  76 extern void selnl_notify_setenforce(int val);
  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;
 145         ssize_t length;
 146         int new_value;
 147
 148         if (count >= PAGE_SIZE)
 149                 return -ENOMEM;
 150         if (*ppos != 0) {
 151                 /* No partial writes. */
 152                 return -EINVAL;
 153         }
 154         page = (char *)get_zeroed_page(GFP_KERNEL);
 155         if (!page)
 156                 return -ENOMEM;
 157         length = -EFAULT;
 158         if (copy_from_user(page, buf, count))
 159                 goto out;
 160
 161         length = -EINVAL;
 162         if (sscanf(page, "%d", &new_value) != 1)
 163                 goto out;
 164
 165         if (new_value != selinux_enforcing) {
 166                 length = task_has_security(current, SECURITY__SETENFORCE);
 167                 if (length)
 168                         goto out;
 169                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 170                         "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 171                         new_value, selinux_enforcing,
 172                         audit_get_loginuid(current),
 173                         audit_get_sessionid(current));
 174                 selinux_enforcing = new_value;
 175                 if (selinux_enforcing)
 176                         avc_ss_reset(0);
 177                 selnl_notify_setenforce(selinux_enforcing);
 178                 selinux_status_update_setenforce(selinux_enforcing);
 179         }
 180         length = count;
 181 out:
 182         free_page((unsigned long) page);
 183         return length;
 184 }
 185 #else
 186 #define sel_write_enforce NULL
 187 #endif
 188
 189 static const struct file_operations sel_enforce_ops = {
 190         .read           = sel_read_enforce,
 191         .write          = sel_write_enforce,
 192         .llseek         = generic_file_llseek,
 193 };
 194
 195 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 196                                         size_t count, loff_t *ppos)
 197 {
 198         char tmpbuf[TMPBUFLEN];
 199         ssize_t length;
 200         ino_t ino = filp->f_path.dentry->d_inode->i_ino;
 201         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 202                 security_get_reject_unknown() : !security_get_allow_unknown();
 203
 204         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 205         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 206 }
 207
 208 static const struct file_operations sel_handle_unknown_ops = {
 209         .read           = sel_read_handle_unknown,
 210         .llseek         = generic_file_llseek,
 211 };
 212
 213 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 214 {
 215         struct page    *status = selinux_kernel_status_page();
 216
 217         if (!status)
 218                 return -ENOMEM;
 219
 220         filp->private_data = status;
 221
 222         return 0;
 223 }
 224
 225 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 226                                       size_t count, loff_t *ppos)
 227 {
 228         struct page    *status = filp->private_data;
 229
 230         BUG_ON(!status);
 231
 232         return simple_read_from_buffer(buf, count, ppos,
 233                                        page_address(status),
 234                                        sizeof(struct selinux_kernel_status));
 235 }
 236
 237 static int sel_mmap_handle_status(struct file *filp,
 238                                   struct vm_area_struct *vma)
 239 {
 240         struct page    *status = filp->private_data;
 241         unsigned long   size = vma->vm_end - vma->vm_start;
 242
 243         BUG_ON(!status);
 244
 245         /* only allows one page from the head */
 246         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 247                 return -EIO;
 248         /* disallow writable mapping */
 249         if (vma->vm_flags & VM_WRITE)
 250                 return -EPERM;
 251         /* disallow mprotect() turns it into writable */
 252         vma->vm_flags &= ~VM_MAYWRITE;
 253
 254         return remap_pfn_range(vma, vma->vm_start,
 255                                page_to_pfn(status),
 256                                size, vma->vm_page_prot);
 257 }
 258
 259 static const struct file_operations sel_handle_status_ops = {
 260         .open           = sel_open_handle_status,
 261         .read           = sel_read_handle_status,
 262         .mmap           = sel_mmap_handle_status,
 263         .llseek         = generic_file_llseek,
 264 };
 265
 266 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 267 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 268                                  size_t count, loff_t *ppos)
 269
 270 {
 271         char *page;
 272         ssize_t length;
 273         int new_value;
 274         extern int selinux_disable(void);
 275
 276         if (count >= PAGE_SIZE)
 277                 return -ENOMEM;
 278         if (*ppos != 0) {
 279                 /* No partial writes. */
 280                 return -EINVAL;
 281         }
 282         page = (char *)get_zeroed_page(GFP_KERNEL);
 283         if (!page)
 284                 return -ENOMEM;
 285         length = -EFAULT;
 286         if (copy_from_user(page, buf, count))
 287                 goto out;
 288
 289         length = -EINVAL;
 290         if (sscanf(page, "%d", &new_value) != 1)
 291                 goto out;
 292
 293         if (new_value) {
 294                 length = selinux_disable();
 295                 if (length < 0)
 296                         goto out;
 297                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 298                         "selinux=0 auid=%u ses=%u",
 299                         audit_get_loginuid(current),
 300                         audit_get_sessionid(current));
 301         }
 302
 303         length = count;
 304 out:
 305         free_page((unsigned long) page);
 306         return length;
 307 }
 308 #else
 309 #define sel_write_disable NULL
 310 #endif
 311
 312 static const struct file_operations sel_disable_ops = {
 313         .write          = sel_write_disable,
 314         .llseek         = generic_file_llseek,
 315 };
 316
 317 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 318                                    size_t count, loff_t *ppos)
 319 {
 320         char tmpbuf[TMPBUFLEN];
 321         ssize_t length;
 322
 323         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 324         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 325 }
 326
 327 static const struct file_operations sel_policyvers_ops = {
 328         .read           = sel_read_policyvers,
 329         .llseek         = generic_file_llseek,
 330 };
 331
 332 /* declaration for sel_write_load */
 333 static int sel_make_bools(void);
 334 static int sel_make_classes(void);
 335 static int sel_make_policycap(void);
 336
 337 /* declaration for sel_make_class_dirs */
 338 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
 339                         unsigned long *ino);
 340
 341 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 342                                 size_t count, loff_t *ppos)
 343 {
 344         char tmpbuf[TMPBUFLEN];
 345         ssize_t length;
 346
 347         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 348                            security_mls_enabled());
 349         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 350 }
 351
 352 static const struct file_operations sel_mls_ops = {
 353         .read           = sel_read_mls,
 354         .llseek         = generic_file_llseek,
 355 };
 356
 357 struct policy_load_memory {
 358         size_t len;
 359         void *data;
 360 };
 361
 362 static int sel_open_policy(struct inode *inode, struct file *filp)
 363 {
 364         struct policy_load_memory *plm = NULL;
 365         int rc;
 366
 367         BUG_ON(filp->private_data);
 368
 369         mutex_lock(&sel_mutex);
 370
 371         rc = task_has_security(current, SECURITY__READ_POLICY);
 372         if (rc)
 373                 goto err;
 374
 375         rc = -EBUSY;
 376         if (policy_opened)
 377                 goto err;
 378
 379         rc = -ENOMEM;
 380         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 381         if (!plm)
 382                 goto err;
 383
 384         if (i_size_read(inode) != security_policydb_len()) {
 385                 mutex_lock(&inode->i_mutex);
 386                 i_size_write(inode, security_policydb_len());
 387                 mutex_unlock(&inode->i_mutex);
 388         }
 389
 390         rc = security_read_policy(&plm->data, &plm->len);
 391         if (rc)
 392                 goto err;
 393
 394         policy_opened = 1;
 395
 396         filp->private_data = plm;
 397
 398         mutex_unlock(&sel_mutex);
 399
 400         return 0;
 401 err:
 402         mutex_unlock(&sel_mutex);
 403
 404         if (plm)
 405                 vfree(plm->data);
 406         kfree(plm);
 407         return rc;
 408 }
 409
 410 static int sel_release_policy(struct inode *inode, struct file *filp)
 411 {
 412         struct policy_load_memory *plm = filp->private_data;
 413
 414         BUG_ON(!plm);
 415
 416         policy_opened = 0;
 417
 418         vfree(plm->data);
 419         kfree(plm);
 420
 421         return 0;
 422 }
 423
 424 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 425                                size_t count, loff_t *ppos)
 426 {
 427         struct policy_load_memory *plm = filp->private_data;
 428         int ret;
 429
 430         mutex_lock(&sel_mutex);
 431
 432         ret = task_has_security(current, SECURITY__READ_POLICY);
 433         if (ret)
 434                 goto out;
 435
 436         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 437 out:
 438         mutex_unlock(&sel_mutex);
 439         return ret;
 440 }
 441
 442 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 443                                  struct vm_fault *vmf)
 444 {
 445         struct policy_load_memory *plm = vma->vm_file->private_data;
 446         unsigned long offset;
 447         struct page *page;
 448
 449         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 450                 return VM_FAULT_SIGBUS;
 451
 452         offset = vmf->pgoff << PAGE_SHIFT;
 453         if (offset >= roundup(plm->len, PAGE_SIZE))
 454                 return VM_FAULT_SIGBUS;
 455
 456         page = vmalloc_to_page(plm->data + offset);
 457         get_page(page);
 458
 459         vmf->page = page;
 460
 461         return 0;
 462 }
 463
 464 static struct vm_operations_struct sel_mmap_policy_ops = {
 465         .fault = sel_mmap_policy_fault,
 466         .page_mkwrite = sel_mmap_policy_fault,
 467 };
 468
 469 int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 470 {
 471         if (vma->vm_flags & VM_SHARED) {
 472                 /* do not allow mprotect to make mapping writable */
 473                 vma->vm_flags &= ~VM_MAYWRITE;
 474
 475                 if (vma->vm_flags & VM_WRITE)
 476                         return -EACCES;
 477         }
 478
 479         vma->vm_flags |= VM_RESERVED;
 480         vma->vm_ops = &sel_mmap_policy_ops;
 481
 482         return 0;
 483 }
 484
 485 static const struct file_operations sel_policy_ops = {
 486         .open           = sel_open_policy,
 487         .read           = sel_read_policy,
 488         .mmap           = sel_mmap_policy,
 489         .release        = sel_release_policy,
 490 };
 491
 492 static ssize_t sel_write_load(struct file *file, const char __user *buf,
 493                               size_t count, loff_t *ppos)
 494
 495 {
 496         int ret;
 497         ssize_t length;
 498         void *data = NULL;
 499
 500         mutex_lock(&sel_mutex);
 501
 502         length = task_has_security(current, SECURITY__LOAD_POLICY);
 503         if (length)
 504                 goto out;
 505
 506         if (*ppos != 0) {
 507                 /* No partial writes. */
 508                 length = -EINVAL;
 509                 goto out;
 510         }
 511
 512         if ((count > 64 * 1024 * 1024)
 513             || (data = vmalloc(count)) == NULL) {
 514                 length = -ENOMEM;
 515                 goto out;
 516         }
 517
 518         length = -EFAULT;
 519         if (copy_from_user(data, buf, count) != 0)
 520                 goto out;
 521
 522         length = security_load_policy(data, count);
 523         if (length)
 524                 goto out;
 525
 526         ret = sel_make_bools();
 527         if (ret) {
 528                 length = ret;
 529                 goto out1;
 530         }
 531
 532         ret = sel_make_classes();
 533         if (ret) {
 534                 length = ret;
 535                 goto out1;
 536         }
 537
 538         ret = sel_make_policycap();
 539         if (ret)
 540                 length = ret;
 541         else
 542                 length = count;
 543
 544 out1:
 545         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 546                 "policy loaded auid=%u ses=%u",
 547                 audit_get_loginuid(current),
 548                 audit_get_sessionid(current));
 549 out:
 550         mutex_unlock(&sel_mutex);
 551         vfree(data);
 552         return length;
 553 }
 554
 555 static const struct file_operations sel_load_ops = {
 556         .write          = sel_write_load,
 557         .llseek         = generic_file_llseek,
 558 };
 559
 560 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 561 {
 562         char *canon;
 563         u32 sid, len;
 564         ssize_t length;
 565
 566         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 567         if (length)
 568                 return length;
 569
 570         length = security_context_to_sid(buf, size, &sid);
 571         if (length < 0)
 572                 return length;
 573
 574         length = security_sid_to_context(sid, &canon, &len);
 575         if (length < 0)
 576                 return length;
 577
 578         if (len > SIMPLE_TRANSACTION_LIMIT) {
 579                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 580                         "payload max\n", __func__, len);
 581                 length = -ERANGE;
 582                 goto out;
 583         }
 584
 585         memcpy(buf, canon, len);
 586         length = len;
 587 out:
 588         kfree(canon);
 589         return length;
 590 }
 591
 592 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 593                                      size_t count, loff_t *ppos)
 594 {
 595         char tmpbuf[TMPBUFLEN];
 596         ssize_t length;
 597
 598         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 599         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 600 }
 601
 602 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 603                                       size_t count, loff_t *ppos)
 604 {
 605         char *page;
 606         ssize_t length;
 607         unsigned int new_value;
 608
 609         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 610         if (length)
 611                 return length;
 612
 613         if (count >= PAGE_SIZE)
 614                 return -ENOMEM;
 615         if (*ppos != 0) {
 616                 /* No partial writes. */
 617                 return -EINVAL;
 618         }
 619         page = (char *)get_zeroed_page(GFP_KERNEL);
 620         if (!page)
 621                 return -ENOMEM;
 622         length = -EFAULT;
 623         if (copy_from_user(page, buf, count))
 624                 goto out;
 625
 626         length = -EINVAL;
 627         if (sscanf(page, "%u", &new_value) != 1)
 628                 goto out;
 629
 630         selinux_checkreqprot = new_value ? 1 : 0;
 631         length = count;
 632 out:
 633         free_page((unsigned long) page);
 634         return length;
 635 }
 636 static const struct file_operations sel_checkreqprot_ops = {
 637         .read           = sel_read_checkreqprot,
 638         .write          = sel_write_checkreqprot,
 639         .llseek         = generic_file_llseek,
 640 };
 641
 642 /*
 643  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 644  */
 645 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 646 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 647 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 648 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 649 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 650
 651 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 652         [SEL_ACCESS] = sel_write_access,
 653         [SEL_CREATE] = sel_write_create,
 654         [SEL_RELABEL] = sel_write_relabel,
 655         [SEL_USER] = sel_write_user,
 656         [SEL_MEMBER] = sel_write_member,
 657         [SEL_CONTEXT] = sel_write_context,
 658 };
 659
 660 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 661 {
 662         ino_t ino = file->f_path.dentry->d_inode->i_ino;
 663         char *data;
 664         ssize_t rv;
 665
 666         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 667                 return -EINVAL;
 668
 669         data = simple_transaction_get(file, buf, size);
 670         if (IS_ERR(data))
 671                 return PTR_ERR(data);
 672
 673         rv = write_op[ino](file, data, size);
 674         if (rv > 0) {
 675                 simple_transaction_set(file, rv);
 676                 rv = size;
 677         }
 678         return rv;
 679 }
 680
 681 static const struct file_operations transaction_ops = {
 682         .write          = selinux_transaction_write,
 683         .read           = simple_transaction_read,
 684         .release        = simple_transaction_release,
 685         .llseek         = generic_file_llseek,
 686 };
 687
 688 /*
 689  * payload - write methods
 690  * If the method has a response, the response should be put in buf,
 691  * and the length returned.  Otherwise return 0 or and -error.
 692  */
 693
 694 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 695 {
 696         char *scon, *tcon;
 697         u32 ssid, tsid;
 698         u16 tclass;
 699         struct av_decision avd;
 700         ssize_t length;
 701
 702         length = task_has_security(current, SECURITY__COMPUTE_AV);
 703         if (length)
 704                 return length;
 705
 706         length = -ENOMEM;
 707         scon = kzalloc(size + 1, GFP_KERNEL);
 708         if (!scon)
 709                 return length;
 710
 711         tcon = kzalloc(size + 1, GFP_KERNEL);
 712         if (!tcon)
 713                 goto out;
 714
 715         length = -EINVAL;
 716         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 717                 goto out2;
 718
 719         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 720         if (length < 0)
 721                 goto out2;
 722         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 723         if (length < 0)
 724                 goto out2;
 725
 726         security_compute_av_user(ssid, tsid, tclass, &avd);
 727
 728         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 729                           "%x %x %x %x %u %x",
 730                           avd.allowed, 0xffffffff,
 731                           avd.auditallow, avd.auditdeny,
 732                           avd.seqno, avd.flags);
 733 out2:
 734         kfree(tcon);
 735 out:
 736         kfree(scon);
 737         return length;
 738 }
 739
 740 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 741 {
 742         char *scon, *tcon;
 743         u32 ssid, tsid, newsid;
 744         u16 tclass;
 745         ssize_t length;
 746         char *newcon;
 747         u32 len;
 748
 749         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 750         if (length)
 751                 return length;
 752
 753         length = -ENOMEM;
 754         scon = kzalloc(size + 1, GFP_KERNEL);
 755         if (!scon)
 756                 return length;
 757
 758         tcon = kzalloc(size + 1, GFP_KERNEL);
 759         if (!tcon)
 760                 goto out;
 761
 762         length = -EINVAL;
 763         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 764                 goto out2;
 765
 766         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 767         if (length < 0)
 768                 goto out2;
 769         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 770         if (length < 0)
 771                 goto out2;
 772
 773         length = security_transition_sid_user(ssid, tsid, tclass, &newsid);
 774         if (length < 0)
 775                 goto out2;
 776
 777         length = security_sid_to_context(newsid, &newcon, &len);
 778         if (length < 0)
 779                 goto out2;
 780
 781         if (len > SIMPLE_TRANSACTION_LIMIT) {
 782                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 783                         "payload max\n", __func__, len);
 784                 length = -ERANGE;
 785                 goto out3;
 786         }
 787
 788         memcpy(buf, newcon, len);
 789         length = len;
 790 out3:
 791         kfree(newcon);
 792 out2:
 793         kfree(tcon);
 794 out:
 795         kfree(scon);
 796         return length;
 797 }
 798
 799 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 800 {
 801         char *scon, *tcon;
 802         u32 ssid, tsid, newsid;
 803         u16 tclass;
 804         ssize_t length;
 805         char *newcon;
 806         u32 len;
 807
 808         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 809         if (length)
 810                 return length;
 811
 812         length = -ENOMEM;
 813         scon = kzalloc(size + 1, GFP_KERNEL);
 814         if (!scon)
 815                 return length;
 816
 817         tcon = kzalloc(size + 1, GFP_KERNEL);
 818         if (!tcon)
 819                 goto out;
 820
 821         length = -EINVAL;
 822         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 823                 goto out2;
 824
 825         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 826         if (length < 0)
 827                 goto out2;
 828         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 829         if (length < 0)
 830                 goto out2;
 831
 832         length = security_change_sid(ssid, tsid, tclass, &newsid);
 833         if (length < 0)
 834                 goto out2;
 835
 836         length = security_sid_to_context(newsid, &newcon, &len);
 837         if (length < 0)
 838                 goto out2;
 839
 840         if (len > SIMPLE_TRANSACTION_LIMIT) {
 841                 length = -ERANGE;
 842                 goto out3;
 843         }
 844
 845         memcpy(buf, newcon, len);
 846         length = len;
 847 out3:
 848         kfree(newcon);
 849 out2:
 850         kfree(tcon);
 851 out:
 852         kfree(scon);
 853         return length;
 854 }
 855
 856 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 857 {
 858         char *con, *user, *ptr;
 859         u32 sid, *sids;
 860         ssize_t length;
 861         char *newcon;
 862         int i, rc;
 863         u32 len, nsids;
 864
 865         length = task_has_security(current, SECURITY__COMPUTE_USER);
 866         if (length)
 867                 return length;
 868
 869         length = -ENOMEM;
 870         con = kzalloc(size + 1, GFP_KERNEL);
 871         if (!con)
 872                 return length;
 873
 874         user = kzalloc(size + 1, GFP_KERNEL);
 875         if (!user)
 876                 goto out;
 877
 878         length = -EINVAL;
 879         if (sscanf(buf, "%s %s", con, user) != 2)
 880                 goto out2;
 881
 882         length = security_context_to_sid(con, strlen(con) + 1, &sid);
 883         if (length < 0)
 884                 goto out2;
 885
 886         length = security_get_user_sids(sid, user, &sids, &nsids);
 887         if (length < 0)
 888                 goto out2;
 889
 890         length = sprintf(buf, "%u", nsids) + 1;
 891         ptr = buf + length;
 892         for (i = 0; i < nsids; i++) {
 893                 rc = security_sid_to_context(sids[i], &newcon, &len);
 894                 if (rc) {
 895                         length = rc;
 896                         goto out3;
 897                 }
 898                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 899                         kfree(newcon);
 900                         length = -ERANGE;
 901                         goto out3;
 902                 }
 903                 memcpy(ptr, newcon, len);
 904                 kfree(newcon);
 905                 ptr += len;
 906                 length += len;
 907         }
 908 out3:
 909         kfree(sids);
 910 out2:
 911         kfree(user);
 912 out:
 913         kfree(con);
 914         return length;
 915 }
 916
 917 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 918 {
 919         char *scon, *tcon;
 920         u32 ssid, tsid, newsid;
 921         u16 tclass;
 922         ssize_t length;
 923         char *newcon;
 924         u32 len;
 925
 926         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 927         if (length)
 928                 return length;
 929
 930         length = -ENOMEM;
 931         scon = kzalloc(size + 1, GFP_KERNEL);
 932         if (!scon)
 933                 return length;
 934
 935         tcon = kzalloc(size + 1, GFP_KERNEL);
 936         if (!tcon)
 937                 goto out;
 938
 939         length = -EINVAL;
 940         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 941                 goto out2;
 942
 943         length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 944         if (length < 0)
 945                 goto out2;
 946         length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 947         if (length < 0)
 948                 goto out2;
 949
 950         length = security_member_sid(ssid, tsid, tclass, &newsid);
 951         if (length < 0)
 952                 goto out2;
 953
 954         length = security_sid_to_context(newsid, &newcon, &len);
 955         if (length < 0)
 956                 goto out2;
 957
 958         if (len > SIMPLE_TRANSACTION_LIMIT) {
 959                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 960                         "payload max\n", __func__, len);
 961                 length = -ERANGE;
 962                 goto out3;
 963         }
 964
 965         memcpy(buf, newcon, len);
 966         length = len;
 967 out3:
 968         kfree(newcon);
 969 out2:
 970         kfree(tcon);
 971 out:
 972         kfree(scon);
 973         return length;
 974 }
 975
 976 static struct inode *sel_make_inode(struct super_block *sb, int mode)
 977 {
 978         struct inode *ret = new_inode(sb);
 979
 980         if (ret) {
 981                 ret->i_ino = get_next_ino();
 982                 ret->i_mode = mode;
 983                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
 984         }
 985         return ret;
 986 }
 987
 988 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 989                              size_t count, loff_t *ppos)
 990 {
 991         char *page = NULL;
 992         ssize_t length;
 993         ssize_t ret;
 994         int cur_enforcing;
 995         struct inode *inode = filep->f_path.dentry->d_inode;
 996         unsigned index = inode->i_ino & SEL_INO_MASK;
 997         const char *name = filep->f_path.dentry->d_name.name;
 998
 999         mutex_lock(&sel_mutex);
1000
1001         if (index >= bool_num || strcmp(name, bool_pending_names[index])) {
1002                 ret = -EINVAL;
1003                 goto out;
1004         }
1005
1006         page = (char *)get_zeroed_page(GFP_KERNEL);
1007         if (!page) {
1008                 ret = -ENOMEM;
1009                 goto out;
1010         }
1011
1012         cur_enforcing = security_get_bool_value(index);
1013         if (cur_enforcing < 0) {
1014                 ret = cur_enforcing;
1015                 goto out;
1016         }
1017         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1018                           bool_pending_values[index]);
1019         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1020 out:
1021         mutex_unlock(&sel_mutex);
1022         if (page)
1023                 free_page((unsigned long)page);
1024         return ret;
1025 }
1026
1027 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1028                               size_t count, loff_t *ppos)
1029 {
1030         char *page = NULL;
1031         ssize_t length;
1032         int new_value;
1033         struct inode *inode = filep->f_path.dentry->d_inode;
1034         unsigned index = inode->i_ino & SEL_INO_MASK;
1035         const char *name = filep->f_path.dentry->d_name.name;
1036
1037         mutex_lock(&sel_mutex);
1038
1039         length = task_has_security(current, SECURITY__SETBOOL);
1040         if (length)
1041                 goto out;
1042
1043         if (index >= bool_num || strcmp(name, bool_pending_names[index])) {
1044                 length = -EINVAL;
1045                 goto out;
1046         }
1047
1048         if (count >= PAGE_SIZE) {
1049                 length = -ENOMEM;
1050                 goto out;
1051         }
1052
1053         if (*ppos != 0) {
1054                 /* No partial writes. */
1055                 length = -EINVAL;
1056                 goto out;
1057         }
1058         page = (char *)get_zeroed_page(GFP_KERNEL);
1059         if (!page) {
1060                 length = -ENOMEM;
1061                 goto out;
1062         }
1063
1064         length = -EFAULT;
1065         if (copy_from_user(page, buf, count))
1066                 goto out;
1067
1068         length = -EINVAL;
1069         if (sscanf(page, "%d", &new_value) != 1)
1070                 goto out;
1071
1072         if (new_value)
1073                 new_value = 1;
1074
1075         bool_pending_values[index] = new_value;
1076         length = count;
1077
1078 out:
1079         mutex_unlock(&sel_mutex);
1080         if (page)
1081                 free_page((unsigned long) page);
1082         return length;
1083 }
1084
1085 static const struct file_operations sel_bool_ops = {
1086         .read           = sel_read_bool,
1087         .write          = sel_write_bool,
1088         .llseek         = generic_file_llseek,
1089 };
1090
1091 static ssize_t sel_commit_bools_write(struct file *filep,
1092                                       const char __user *buf,
1093                                       size_t count, loff_t *ppos)
1094 {
1095         char *page = NULL;
1096         ssize_t length;
1097         int new_value;
1098
1099         mutex_lock(&sel_mutex);
1100
1101         length = task_has_security(current, SECURITY__SETBOOL);
1102         if (length)
1103                 goto out;
1104
1105         if (count >= PAGE_SIZE) {
1106                 length = -ENOMEM;
1107                 goto out;
1108         }
1109         if (*ppos != 0) {
1110                 /* No partial writes. */
1111                 goto out;
1112         }
1113         page = (char *)get_zeroed_page(GFP_KERNEL);
1114         if (!page) {
1115                 length = -ENOMEM;
1116                 goto out;
1117         }
1118
1119         length = -EFAULT;
1120         if (copy_from_user(page, buf, count))
1121                 goto out;
1122
1123         length = -EINVAL;
1124         if (sscanf(page, "%d", &new_value) != 1)
1125                 goto out;
1126
1127         if (new_value && bool_pending_values)
1128                 security_set_bools(bool_num, bool_pending_values);
1129
1130         length = count;
1131
1132 out:
1133         mutex_unlock(&sel_mutex);
1134         if (page)
1135                 free_page((unsigned long) page);
1136         return length;
1137 }
1138
1139 static const struct file_operations sel_commit_bools_ops = {
1140         .write          = sel_commit_bools_write,
1141         .llseek         = generic_file_llseek,
1142 };
1143
1144 static void sel_remove_entries(struct dentry *de)
1145 {
1146         struct list_head *node;
1147
1148         spin_lock(&dcache_lock);
1149         node = de->d_subdirs.next;
1150         while (node != &de->d_subdirs) {
1151                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1152                 list_del_init(node);
1153
1154                 if (d->d_inode) {
1155                         d = dget_locked(d);
1156                         spin_unlock(&dcache_lock);
1157                         d_delete(d);
1158                         simple_unlink(de->d_inode, d);
1159                         dput(d);
1160                         spin_lock(&dcache_lock);
1161                 }
1162                 node = de->d_subdirs.next;
1163         }
1164
1165         spin_unlock(&dcache_lock);
1166 }
1167
1168 #define BOOL_DIR_NAME "booleans"
1169
1170 static int sel_make_bools(void)
1171 {
1172         int i, ret = 0;
1173         ssize_t len;
1174         struct dentry *dentry = NULL;
1175         struct dentry *dir = bool_dir;
1176         struct inode *inode = NULL;
1177         struct inode_security_struct *isec;
1178         char **names = NULL, *page;
1179         int num;
1180         int *values = NULL;
1181         u32 sid;
1182
1183         /* remove any existing files */
1184         for (i = 0; i < bool_num; i++)
1185                 kfree(bool_pending_names[i]);
1186         kfree(bool_pending_names);
1187         kfree(bool_pending_values);
1188         bool_pending_names = NULL;
1189         bool_pending_values = NULL;
1190
1191         sel_remove_entries(dir);
1192
1193         page = (char *)get_zeroed_page(GFP_KERNEL);
1194         if (!page)
1195                 return -ENOMEM;
1196
1197         ret = security_get_bools(&num, &names, &values);
1198         if (ret != 0)
1199                 goto out;
1200
1201         for (i = 0; i < num; i++) {
1202                 dentry = d_alloc_name(dir, names[i]);
1203                 if (!dentry) {
1204                         ret = -ENOMEM;
1205                         goto err;
1206                 }
1207                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1208                 if (!inode) {
1209                         ret = -ENOMEM;
1210                         goto err;
1211                 }
1212
1213                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1214                 if (len < 0) {
1215                         ret = -EINVAL;
1216                         goto err;
1217                 } else if (len >= PAGE_SIZE) {
1218                         ret = -ENAMETOOLONG;
1219                         goto err;
1220                 }
1221                 isec = (struct inode_security_struct *)inode->i_security;
1222                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1223                 if (ret)
1224                         goto err;
1225                 isec->sid = sid;
1226                 isec->initialized = 1;
1227                 inode->i_fop = &sel_bool_ops;
1228                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1229                 d_add(dentry, inode);
1230         }
1231         bool_num = num;
1232         bool_pending_names = names;
1233         bool_pending_values = values;
1234 out:
1235         free_page((unsigned long)page);
1236         return ret;
1237 err:
1238         if (names) {
1239                 for (i = 0; i < num; i++)
1240                         kfree(names[i]);
1241                 kfree(names);
1242         }
1243         kfree(values);
1244         sel_remove_entries(dir);
1245         ret = -ENOMEM;
1246         goto out;
1247 }
1248
1249 #define NULL_FILE_NAME "null"
1250
1251 struct dentry *selinux_null;
1252
1253 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1254                                             size_t count, loff_t *ppos)
1255 {
1256         char tmpbuf[TMPBUFLEN];
1257         ssize_t length;
1258
1259         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1260         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1261 }
1262
1263 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1264                                              const char __user *buf,
1265                                              size_t count, loff_t *ppos)
1266
1267 {
1268         char *page;
1269         ssize_t ret;
1270         int new_value;
1271
1272         if (count >= PAGE_SIZE) {
1273                 ret = -ENOMEM;
1274                 goto out;
1275         }
1276
1277         if (*ppos != 0) {
1278                 /* No partial writes. */
1279                 ret = -EINVAL;
1280                 goto out;
1281         }
1282
1283         page = (char *)get_zeroed_page(GFP_KERNEL);
1284         if (!page) {
1285                 ret = -ENOMEM;
1286                 goto out;
1287         }
1288
1289         if (copy_from_user(page, buf, count)) {
1290                 ret = -EFAULT;
1291                 goto out_free;
1292         }
1293
1294         if (sscanf(page, "%u", &new_value) != 1) {
1295                 ret = -EINVAL;
1296                 goto out;
1297         }
1298
1299         if (new_value != avc_cache_threshold) {
1300                 ret = task_has_security(current, SECURITY__SETSECPARAM);
1301                 if (ret)
1302                         goto out_free;
1303                 avc_cache_threshold = new_value;
1304         }
1305         ret = count;
1306 out_free:
1307         free_page((unsigned long)page);
1308 out:
1309         return ret;
1310 }
1311
1312 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1313                                        size_t count, loff_t *ppos)
1314 {
1315         char *page;
1316         ssize_t ret = 0;
1317
1318         page = (char *)__get_free_page(GFP_KERNEL);
1319         if (!page) {
1320                 ret = -ENOMEM;
1321                 goto out;
1322         }
1323         ret = avc_get_hash_stats(page);
1324         if (ret >= 0)
1325                 ret = simple_read_from_buffer(buf, count, ppos, page, ret);
1326         free_page((unsigned long)page);
1327 out:
1328         return ret;
1329 }
1330
1331 static const struct file_operations sel_avc_cache_threshold_ops = {
1332         .read           = sel_read_avc_cache_threshold,
1333         .write          = sel_write_avc_cache_threshold,
1334         .llseek         = generic_file_llseek,
1335 };
1336
1337 static const struct file_operations sel_avc_hash_stats_ops = {
1338         .read           = sel_read_avc_hash_stats,
1339         .llseek         = generic_file_llseek,
1340 };
1341
1342 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1343 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1344 {
1345         int cpu;
1346
1347         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1348                 if (!cpu_possible(cpu))
1349                         continue;
1350                 *idx = cpu + 1;
1351                 return &per_cpu(avc_cache_stats, cpu);
1352         }
1353         return NULL;
1354 }
1355
1356 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1357 {
1358         loff_t n = *pos - 1;
1359
1360         if (*pos == 0)
1361                 return SEQ_START_TOKEN;
1362
1363         return sel_avc_get_stat_idx(&n);
1364 }
1365
1366 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1367 {
1368         return sel_avc_get_stat_idx(pos);
1369 }
1370
1371 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1372 {
1373         struct avc_cache_stats *st = v;
1374
1375         if (v == SEQ_START_TOKEN)
1376                 seq_printf(seq, "lookups hits misses allocations reclaims "
1377                            "frees\n");
1378         else
1379                 seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
1380                            st->hits, st->misses, st->allocations,
1381                            st->reclaims, st->frees);
1382         return 0;
1383 }
1384
1385 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1386 { }
1387
1388 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1389         .start          = sel_avc_stats_seq_start,
1390         .next           = sel_avc_stats_seq_next,
1391         .show           = sel_avc_stats_seq_show,
1392         .stop           = sel_avc_stats_seq_stop,
1393 };
1394
1395 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1396 {
1397         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1398 }
1399
1400 static const struct file_operations sel_avc_cache_stats_ops = {
1401         .open           = sel_open_avc_cache_stats,
1402         .read           = seq_read,
1403         .llseek         = seq_lseek,
1404         .release        = seq_release,
1405 };
1406 #endif
1407
1408 static int sel_make_avc_files(struct dentry *dir)
1409 {
1410         int i, ret = 0;
1411         static struct tree_descr files[] = {
1412                 { "cache_threshold",
1413                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1414                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1415 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1416                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1417 #endif
1418         };
1419
1420         for (i = 0; i < ARRAY_SIZE(files); i++) {
1421                 struct inode *inode;
1422                 struct dentry *dentry;
1423
1424                 dentry = d_alloc_name(dir, files[i].name);
1425                 if (!dentry) {
1426                         ret = -ENOMEM;
1427                         goto out;
1428                 }
1429
1430                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1431                 if (!inode) {
1432                         ret = -ENOMEM;
1433                         goto out;
1434                 }
1435                 inode->i_fop = files[i].ops;
1436                 inode->i_ino = ++sel_last_ino;
1437                 d_add(dentry, inode);
1438         }
1439 out:
1440         return ret;
1441 }
1442
1443 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1444                                 size_t count, loff_t *ppos)
1445 {
1446         struct inode *inode;
1447         char *con;
1448         u32 sid, len;
1449         ssize_t ret;
1450
1451         inode = file->f_path.dentry->d_inode;
1452         sid = inode->i_ino&SEL_INO_MASK;
1453         ret = security_sid_to_context(sid, &con, &len);
1454         if (ret < 0)
1455                 return ret;
1456
1457         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1458         kfree(con);
1459         return ret;
1460 }
1461
1462 static const struct file_operations sel_initcon_ops = {
1463         .read           = sel_read_initcon,
1464         .llseek         = generic_file_llseek,
1465 };
1466
1467 static int sel_make_initcon_files(struct dentry *dir)
1468 {
1469         int i, ret = 0;
1470
1471         for (i = 1; i <= SECINITSID_NUM; i++) {
1472                 struct inode *inode;
1473                 struct dentry *dentry;
1474                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1475                 if (!dentry) {
1476                         ret = -ENOMEM;
1477                         goto out;
1478                 }
1479
1480                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1481                 if (!inode) {
1482                         ret = -ENOMEM;
1483                         goto out;
1484                 }
1485                 inode->i_fop = &sel_initcon_ops;
1486                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1487                 d_add(dentry, inode);
1488         }
1489 out:
1490         return ret;
1491 }
1492
1493 static inline unsigned int sel_div(unsigned long a, unsigned long b)
1494 {
1495         return a / b - (a % b < 0);
1496 }
1497
1498 static inline unsigned long sel_class_to_ino(u16 class)
1499 {
1500         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1501 }
1502
1503 static inline u16 sel_ino_to_class(unsigned long ino)
1504 {
1505         return sel_div(ino & SEL_INO_MASK, SEL_VEC_MAX + 1);
1506 }
1507
1508 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1509 {
1510         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1511 }
1512
1513 static inline u32 sel_ino_to_perm(unsigned long ino)
1514 {
1515         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1516 }
1517
1518 static ssize_t sel_read_class(struct file *file, char __user *buf,
1519                                 size_t count, loff_t *ppos)
1520 {
1521         ssize_t rc, len;
1522         char *page;
1523         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1524
1525         page = (char *)__get_free_page(GFP_KERNEL);
1526         if (!page) {
1527                 rc = -ENOMEM;
1528                 goto out;
1529         }
1530
1531         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
1532         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1533         free_page((unsigned long)page);
1534 out:
1535         return rc;
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         ssize_t rc, len;
1547         char *page;
1548         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1549
1550         page = (char *)__get_free_page(GFP_KERNEL);
1551         if (!page) {
1552                 rc = -ENOMEM;
1553                 goto out;
1554         }
1555
1556         len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
1557         rc = simple_read_from_buffer(buf, count, ppos, page, len);
1558         free_page((unsigned long)page);
1559 out:
1560         return rc;
1561 }
1562
1563 static const struct file_operations sel_perm_ops = {
1564         .read           = sel_read_perm,
1565         .llseek         = generic_file_llseek,
1566 };
1567
1568 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1569                                   size_t count, loff_t *ppos)
1570 {
1571         int value;
1572         char tmpbuf[TMPBUFLEN];
1573         ssize_t length;
1574         unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1575
1576         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1577         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1578
1579         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1580 }
1581
1582 static const struct file_operations sel_policycap_ops = {
1583         .read           = sel_read_policycap,
1584         .llseek         = generic_file_llseek,
1585 };
1586
1587 static int sel_make_perm_files(char *objclass, int classvalue,
1588                                 struct dentry *dir)
1589 {
1590         int i, rc = 0, nperms;
1591         char **perms;
1592
1593         rc = security_get_permissions(objclass, &perms, &nperms);
1594         if (rc)
1595                 goto out;
1596
1597         for (i = 0; i < nperms; i++) {
1598                 struct inode *inode;
1599                 struct dentry *dentry;
1600
1601                 dentry = d_alloc_name(dir, perms[i]);
1602                 if (!dentry) {
1603                         rc = -ENOMEM;
1604                         goto out1;
1605                 }
1606
1607                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1608                 if (!inode) {
1609                         rc = -ENOMEM;
1610                         goto out1;
1611                 }
1612                 inode->i_fop = &sel_perm_ops;
1613                 /* i+1 since perm values are 1-indexed */
1614                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1615                 d_add(dentry, inode);
1616         }
1617
1618 out1:
1619         for (i = 0; i < nperms; i++)
1620                 kfree(perms[i]);
1621         kfree(perms);
1622 out:
1623         return rc;
1624 }
1625
1626 static int sel_make_class_dir_entries(char *classname, int index,
1627                                         struct dentry *dir)
1628 {
1629         struct dentry *dentry = NULL;
1630         struct inode *inode = NULL;
1631         int rc;
1632
1633         dentry = d_alloc_name(dir, "index");
1634         if (!dentry) {
1635                 rc = -ENOMEM;
1636                 goto out;
1637         }
1638
1639         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1640         if (!inode) {
1641                 rc = -ENOMEM;
1642                 goto out;
1643         }
1644
1645         inode->i_fop = &sel_class_ops;
1646         inode->i_ino = sel_class_to_ino(index);
1647         d_add(dentry, inode);
1648
1649         dentry = d_alloc_name(dir, "perms");
1650         if (!dentry) {
1651                 rc = -ENOMEM;
1652                 goto out;
1653         }
1654
1655         rc = sel_make_dir(dir->d_inode, dentry, &last_class_ino);
1656         if (rc)
1657                 goto out;
1658
1659         rc = sel_make_perm_files(classname, index, dentry);
1660
1661 out:
1662         return rc;
1663 }
1664
1665 static void sel_remove_classes(void)
1666 {
1667         struct list_head *class_node;
1668
1669         list_for_each(class_node, &class_dir->d_subdirs) {
1670                 struct dentry *class_subdir = list_entry(class_node,
1671                                         struct dentry, d_u.d_child);
1672                 struct list_head *class_subdir_node;
1673
1674                 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1675                         struct dentry *d = list_entry(class_subdir_node,
1676                                                 struct dentry, d_u.d_child);
1677
1678                         if (d->d_inode)
1679                                 if (d->d_inode->i_mode & S_IFDIR)
1680                                         sel_remove_entries(d);
1681                 }
1682
1683                 sel_remove_entries(class_subdir);
1684         }
1685
1686         sel_remove_entries(class_dir);
1687 }
1688
1689 static int sel_make_classes(void)
1690 {
1691         int rc = 0, nclasses, i;
1692         char **classes;
1693
1694         /* delete any existing entries */
1695         sel_remove_classes();
1696
1697         rc = security_get_classes(&classes, &nclasses);
1698         if (rc < 0)
1699                 goto out;
1700
1701         /* +2 since classes are 1-indexed */
1702         last_class_ino = sel_class_to_ino(nclasses + 2);
1703
1704         for (i = 0; i < nclasses; i++) {
1705                 struct dentry *class_name_dir;
1706
1707                 class_name_dir = d_alloc_name(class_dir, classes[i]);
1708                 if (!class_name_dir) {
1709                         rc = -ENOMEM;
1710                         goto out1;
1711                 }
1712
1713                 rc = sel_make_dir(class_dir->d_inode, class_name_dir,
1714                                 &last_class_ino);
1715                 if (rc)
1716                         goto out1;
1717
1718                 /* i+1 since class values are 1-indexed */
1719                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1720                                 class_name_dir);
1721                 if (rc)
1722                         goto out1;
1723         }
1724
1725 out1:
1726         for (i = 0; i < nclasses; i++)
1727                 kfree(classes[i]);
1728         kfree(classes);
1729 out:
1730         return rc;
1731 }
1732
1733 static int sel_make_policycap(void)
1734 {
1735         unsigned int iter;
1736         struct dentry *dentry = NULL;
1737         struct inode *inode = NULL;
1738
1739         sel_remove_entries(policycap_dir);
1740
1741         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1742                 if (iter < ARRAY_SIZE(policycap_names))
1743                         dentry = d_alloc_name(policycap_dir,
1744                                               policycap_names[iter]);
1745                 else
1746                         dentry = d_alloc_name(policycap_dir, "unknown");
1747
1748                 if (dentry == NULL)
1749                         return -ENOMEM;
1750
1751                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1752                 if (inode == NULL)
1753                         return -ENOMEM;
1754
1755                 inode->i_fop = &sel_policycap_ops;
1756                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1757                 d_add(dentry, inode);
1758         }
1759
1760         return 0;
1761 }
1762
1763 static int sel_make_dir(struct inode *dir, struct dentry *dentry,
1764                         unsigned long *ino)
1765 {
1766         int ret = 0;
1767         struct inode *inode;
1768
1769         inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1770         if (!inode) {
1771                 ret = -ENOMEM;
1772                 goto out;
1773         }
1774         inode->i_op = &simple_dir_inode_operations;
1775         inode->i_fop = &simple_dir_operations;
1776         inode->i_ino = ++(*ino);
1777         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1778         inc_nlink(inode);
1779         d_add(dentry, inode);
1780         /* bump link count on parent directory, too */
1781         inc_nlink(dir);
1782 out:
1783         return ret;
1784 }
1785
1786 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1787 {
1788         int ret;
1789         struct dentry *dentry;
1790         struct inode *inode, *root_inode;
1791         struct inode_security_struct *isec;
1792
1793         static struct tree_descr selinux_files[] = {
1794                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1795                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1796                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1797                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1798                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1799                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1800                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1801                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1802                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1803                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1804                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1805                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1806                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1807                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1808                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1809                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1810                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUSR},
1811                 /* last one */ {""}
1812         };
1813         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1814         if (ret)
1815                 goto err;
1816
1817         root_inode = sb->s_root->d_inode;
1818
1819         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1820         if (!dentry) {
1821                 ret = -ENOMEM;
1822                 goto err;
1823         }
1824
1825         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1826         if (ret)
1827                 goto err;
1828
1829         bool_dir = dentry;
1830
1831         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1832         if (!dentry) {
1833                 ret = -ENOMEM;
1834                 goto err;
1835         }
1836
1837         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1838         if (!inode) {
1839                 ret = -ENOMEM;
1840                 goto err;
1841         }
1842         inode->i_ino = ++sel_last_ino;
1843         isec = (struct inode_security_struct *)inode->i_security;
1844         isec->sid = SECINITSID_DEVNULL;
1845         isec->sclass = SECCLASS_CHR_FILE;
1846         isec->initialized = 1;
1847
1848         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1849         d_add(dentry, inode);
1850         selinux_null = dentry;
1851
1852         dentry = d_alloc_name(sb->s_root, "avc");
1853         if (!dentry) {
1854                 ret = -ENOMEM;
1855                 goto err;
1856         }
1857
1858         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1859         if (ret)
1860                 goto err;
1861
1862         ret = sel_make_avc_files(dentry);
1863         if (ret)
1864                 goto err;
1865
1866         dentry = d_alloc_name(sb->s_root, "initial_contexts");
1867         if (!dentry) {
1868                 ret = -ENOMEM;
1869                 goto err;
1870         }
1871
1872         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1873         if (ret)
1874                 goto err;
1875
1876         ret = sel_make_initcon_files(dentry);
1877         if (ret)
1878                 goto err;
1879
1880         dentry = d_alloc_name(sb->s_root, "class");
1881         if (!dentry) {
1882                 ret = -ENOMEM;
1883                 goto err;
1884         }
1885
1886         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1887         if (ret)
1888                 goto err;
1889
1890         class_dir = dentry;
1891
1892         dentry = d_alloc_name(sb->s_root, "policy_capabilities");
1893         if (!dentry) {
1894                 ret = -ENOMEM;
1895                 goto err;
1896         }
1897
1898         ret = sel_make_dir(root_inode, dentry, &sel_last_ino);
1899         if (ret)
1900                 goto err;
1901
1902         policycap_dir = dentry;
1903
1904 out:
1905         return ret;
1906 err:
1907         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1908                 __func__);
1909         goto out;
1910 }
1911
1912 static struct dentry *sel_mount(struct file_system_type *fs_type,
1913                       int flags, const char *dev_name, void *data)
1914 {
1915         return mount_single(fs_type, flags, data, sel_fill_super);
1916 }
1917
1918 static struct file_system_type sel_fs_type = {
1919         .name           = "selinuxfs",
1920         .mount          = sel_mount,
1921         .kill_sb        = kill_litter_super,
1922 };
1923
1924 struct vfsmount *selinuxfs_mount;
1925
1926 static int __init init_sel_fs(void)
1927 {
1928         int err;
1929
1930         if (!selinux_enabled)
1931                 return 0;
1932         err = register_filesystem(&sel_fs_type);
1933         if (!err) {
1934                 selinuxfs_mount = kern_mount(&sel_fs_type);
1935                 if (IS_ERR(selinuxfs_mount)) {
1936                         printk(KERN_ERR "selinuxfs:  could not mount!\n");
1937                         err = PTR_ERR(selinuxfs_mount);
1938                         selinuxfs_mount = NULL;
1939                 }
1940         }
1941         return err;
1942 }
1943
1944 __initcall(init_sel_fs);
1945
1946 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1947 void exit_sel_fs(void)
1948 {
1949         unregister_filesystem(&sel_fs_type);
1950 }
1951 #endif