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