security/selinux/selinuxfs.c

   1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
   2  *
   3  *      Added conditional policy language extensions
   4  *
   5  *  Updated: Hewlett-Packard <paul@paul-moore.com>
   6  *
   7  *      Added support for the policy capability bitmap
   8  *
   9  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  10  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  11  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  12  *      This program is free software; you can redistribute it and/or modify
  13  *      it under the terms of the GNU General Public License as published by
  14  *      the Free Software Foundation, version 2.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/slab.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/fs.h>
  22 #include <linux/mutex.h>
  23 #include <linux/init.h>
  24 #include <linux/string.h>
  25 #include <linux/security.h>
  26 #include <linux/major.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/percpu.h>
  29 #include <linux/audit.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/kobject.h>
  32 #include <linux/ctype.h>
  33
  34 /* selinuxfs pseudo filesystem for exporting the security policy API.
  35    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  36
  37 #include "flask.h"
  38 #include "avc.h"
  39 #include "avc_ss.h"
  40 #include "security.h"
  41 #include "objsec.h"
  42 #include "conditional.h"
  43
  44 /* Policy capability filenames */
  45 static char *policycap_names[] = {
  46         "network_peer_controls",
  47         "open_perms",
  48         "redhat1",
  49         "always_check_network"
  50 };
  51
  52 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  53
  54 static int __init checkreqprot_setup(char *str)
  55 {
  56         unsigned long checkreqprot;
  57         if (!kstrtoul(str, 0, &checkreqprot))
  58                 selinux_checkreqprot = checkreqprot ? 1 : 0;
  59         return 1;
  60 }
  61 __setup("checkreqprot=", checkreqprot_setup);
  62
  63 static DEFINE_MUTEX(sel_mutex);
  64
  65 /* global data for booleans */
  66 static struct dentry *bool_dir;
  67 static int bool_num;
  68 static char **bool_pending_names;
  69 static int *bool_pending_values;
  70
  71 /* global data for classes */
  72 static struct dentry *class_dir;
  73 static unsigned long last_class_ino;
  74
  75 static char policy_opened;
  76
  77 /* global data for policy capabilities */
  78 static struct dentry *policycap_dir;
  79
  80 /* Check whether a task is allowed to use a security operation. */
  81 static int task_has_security(struct task_struct *tsk,
  82                              u32 perms)
  83 {
  84         const struct task_security_struct *tsec;
  85         u32 sid = 0;
  86
  87         rcu_read_lock();
  88         tsec = __task_cred(tsk)->security;
  89         if (tsec)
  90                 sid = tsec->sid;
  91         rcu_read_unlock();
  92         if (!tsec)
  93                 return -EACCES;
  94
  95         return avc_has_perm(sid, SECINITSID_SECURITY,
  96                             SECCLASS_SECURITY, perms, NULL);
  97 }
  98
  99 enum sel_inos {
 100         SEL_ROOT_INO = 2,
 101         SEL_LOAD,       /* load policy */
 102         SEL_ENFORCE,    /* get or set enforcing status */
 103         SEL_CONTEXT,    /* validate context */
 104         SEL_ACCESS,     /* compute access decision */
 105         SEL_CREATE,     /* compute create labeling decision */
 106         SEL_RELABEL,    /* compute relabeling decision */
 107         SEL_USER,       /* compute reachable user contexts */
 108         SEL_POLICYVERS, /* return policy version for this kernel */
 109         SEL_COMMIT_BOOLS, /* commit new boolean values */
 110         SEL_MLS,        /* return if MLS policy is enabled */
 111         SEL_DISABLE,    /* disable SELinux until next reboot */
 112         SEL_MEMBER,     /* compute polyinstantiation membership decision */
 113         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 114         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 115         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
 116         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 117         SEL_STATUS,     /* export current status using mmap() */
 118         SEL_POLICY,     /* allow userspace to read the in kernel policy */
 119         SEL_VALIDATE_TRANS, /* compute validatetrans decision */
 120         SEL_INO_NEXT,   /* The next inode number to use */
 121 };
 122
 123 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 124
 125 #define SEL_INITCON_INO_OFFSET          0x01000000
 126 #define SEL_BOOL_INO_OFFSET             0x02000000
 127 #define SEL_CLASS_INO_OFFSET            0x04000000
 128 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
 129 #define SEL_INO_MASK                    0x00ffffff
 130
 131 #define TMPBUFLEN       12
 132 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 133                                 size_t count, loff_t *ppos)
 134 {
 135         char tmpbuf[TMPBUFLEN];
 136         ssize_t length;
 137
 138         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 139         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 140 }
 141
 142 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 143 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 144                                  size_t count, loff_t *ppos)
 145
 146 {
 147         char *page = NULL;
 148         ssize_t length;
 149         int new_value;
 150
 151         if (count >= PAGE_SIZE)
 152                 return -ENOMEM;
 153
 154         /* No partial writes. */
 155         if (*ppos != 0)
 156                 return -EINVAL;
 157
 158         page = memdup_user_nul(buf, count);
 159         if (IS_ERR(page))
 160                 return PTR_ERR(page);
 161
 162         length = -EINVAL;
 163         if (sscanf(page, "%d", &new_value) != 1)
 164                 goto out;
 165
 166         if (new_value != selinux_enforcing) {
 167                 length = task_has_security(current, SECURITY__SETENFORCE);
 168                 if (length)
 169                         goto out;
 170                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 171                         "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 172                         new_value, selinux_enforcing,
 173                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
 174                         audit_get_sessionid(current));
 175                 selinux_enforcing = new_value;
 176                 if (selinux_enforcing)
 177                         avc_ss_reset(0);
 178                 selnl_notify_setenforce(selinux_enforcing);
 179                 selinux_status_update_setenforce(selinux_enforcing);
 180         }
 181         length = count;
 182 out:
 183         kfree(page);
 184         return length;
 185 }
 186 #else
 187 #define sel_write_enforce NULL
 188 #endif
 189
 190 static const struct file_operations sel_enforce_ops = {
 191         .read           = sel_read_enforce,
 192         .write          = sel_write_enforce,
 193         .llseek         = generic_file_llseek,
 194 };
 195
 196 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 197                                         size_t count, loff_t *ppos)
 198 {
 199         char tmpbuf[TMPBUFLEN];
 200         ssize_t length;
 201         ino_t ino = file_inode(filp)->i_ino;
 202         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 203                 security_get_reject_unknown() : !security_get_allow_unknown();
 204
 205         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 206         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 207 }
 208
 209 static const struct file_operations sel_handle_unknown_ops = {
 210         .read           = sel_read_handle_unknown,
 211         .llseek         = generic_file_llseek,
 212 };
 213
 214 static int sel_open_handle_status(struct inode *inode, struct file *filp)
 215 {
 216         struct page    *status = selinux_kernel_status_page();
 217
 218         if (!status)
 219                 return -ENOMEM;
 220
 221         filp->private_data = status;
 222
 223         return 0;
 224 }
 225
 226 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 227                                       size_t count, loff_t *ppos)
 228 {
 229         struct page    *status = filp->private_data;
 230
 231         BUG_ON(!status);
 232
 233         return simple_read_from_buffer(buf, count, ppos,
 234                                        page_address(status),
 235                                        sizeof(struct selinux_kernel_status));
 236 }
 237
 238 static int sel_mmap_handle_status(struct file *filp,
 239                                   struct vm_area_struct *vma)
 240 {
 241         struct page    *status = filp->private_data;
 242         unsigned long   size = vma->vm_end - vma->vm_start;
 243
 244         BUG_ON(!status);
 245
 246         /* only allows one page from the head */
 247         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 248                 return -EIO;
 249         /* disallow writable mapping */
 250         if (vma->vm_flags & VM_WRITE)
 251                 return -EPERM;
 252         /* disallow mprotect() turns it into writable */
 253         vma->vm_flags &= ~VM_MAYWRITE;
 254
 255         return remap_pfn_range(vma, vma->vm_start,
 256                                page_to_pfn(status),
 257                                size, vma->vm_page_prot);
 258 }
 259
 260 static const struct file_operations sel_handle_status_ops = {
 261         .open           = sel_open_handle_status,
 262         .read           = sel_read_handle_status,
 263         .mmap           = sel_mmap_handle_status,
 264         .llseek         = generic_file_llseek,
 265 };
 266
 267 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 268 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 269                                  size_t count, loff_t *ppos)
 270
 271 {
 272         char *page;
 273         ssize_t length;
 274         int new_value;
 275
 276         if (count >= PAGE_SIZE)
 277                 return -ENOMEM;
 278
 279         /* No partial writes. */
 280         if (*ppos != 0)
 281                 return -EINVAL;
 282
 283         page = memdup_user_nul(buf, count);
 284         if (IS_ERR(page))
 285                 return PTR_ERR(page);
 286
 287         length = -EINVAL;
 288         if (sscanf(page, "%d", &new_value) != 1)
 289                 goto out;
 290
 291         if (new_value) {
 292                 length = selinux_disable();
 293                 if (length)
 294                         goto out;
 295                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 296                         "selinux=0 auid=%u ses=%u",
 297                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
 298                         audit_get_sessionid(current));
 299         }
 300
 301         length = count;
 302 out:
 303         kfree(page);
 304         return length;
 305 }
 306 #else
 307 #define sel_write_disable NULL
 308 #endif
 309
 310 static const struct file_operations sel_disable_ops = {
 311         .write          = sel_write_disable,
 312         .llseek         = generic_file_llseek,
 313 };
 314
 315 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 316                                    size_t count, loff_t *ppos)
 317 {
 318         char tmpbuf[TMPBUFLEN];
 319         ssize_t length;
 320
 321         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 322         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 323 }
 324
 325 static const struct file_operations sel_policyvers_ops = {
 326         .read           = sel_read_policyvers,
 327         .llseek         = generic_file_llseek,
 328 };
 329
 330 /* declaration for sel_write_load */
 331 static int sel_make_bools(void);
 332 static int sel_make_classes(void);
 333 static int sel_make_policycap(void);
 334
 335 /* declaration for sel_make_class_dirs */
 336 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 337                         unsigned long *ino);
 338
 339 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 340                                 size_t count, loff_t *ppos)
 341 {
 342         char tmpbuf[TMPBUFLEN];
 343         ssize_t length;
 344
 345         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 346                            security_mls_enabled());
 347         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 348 }
 349
 350 static const struct file_operations sel_mls_ops = {
 351         .read           = sel_read_mls,
 352         .llseek         = generic_file_llseek,
 353 };
 354
 355 struct policy_load_memory {
 356         size_t len;
 357         void *data;
 358 };
 359
 360 static int sel_open_policy(struct inode *inode, struct file *filp)
 361 {
 362         struct policy_load_memory *plm = NULL;
 363         int rc;
 364
 365         BUG_ON(filp->private_data);
 366
 367         mutex_lock(&sel_mutex);
 368
 369         rc = task_has_security(current, SECURITY__READ_POLICY);
 370         if (rc)
 371                 goto err;
 372
 373         rc = -EBUSY;
 374         if (policy_opened)
 375                 goto err;
 376
 377         rc = -ENOMEM;
 378         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 379         if (!plm)
 380                 goto err;
 381
 382         if (i_size_read(inode) != security_policydb_len()) {
 383                 inode_lock(inode);
 384                 i_size_write(inode, security_policydb_len());
 385                 inode_unlock(inode);
 386         }
 387
 388         rc = security_read_policy(&plm->data, &plm->len);
 389         if (rc)
 390                 goto err;
 391
 392         policy_opened = 1;
 393
 394         filp->private_data = plm;
 395
 396         mutex_unlock(&sel_mutex);
 397
 398         return 0;
 399 err:
 400         mutex_unlock(&sel_mutex);
 401
 402         if (plm)
 403                 vfree(plm->data);
 404         kfree(plm);
 405         return rc;
 406 }
 407
 408 static int sel_release_policy(struct inode *inode, struct file *filp)
 409 {
 410         struct policy_load_memory *plm = filp->private_data;
 411
 412         BUG_ON(!plm);
 413
 414         policy_opened = 0;
 415
 416         vfree(plm->data);
 417         kfree(plm);
 418
 419         return 0;
 420 }
 421
 422 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 423                                size_t count, loff_t *ppos)
 424 {
 425         struct policy_load_memory *plm = filp->private_data;
 426         int ret;
 427
 428         mutex_lock(&sel_mutex);
 429
 430         ret = task_has_security(current, SECURITY__READ_POLICY);
 431         if (ret)
 432                 goto out;
 433
 434         ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 435 out:
 436         mutex_unlock(&sel_mutex);
 437         return ret;
 438 }
 439
 440 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 441                                  struct vm_fault *vmf)
 442 {
 443         struct policy_load_memory *plm = vma->vm_file->private_data;
 444         unsigned long offset;
 445         struct page *page;
 446
 447         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 448                 return VM_FAULT_SIGBUS;
 449
 450         offset = vmf->pgoff << PAGE_SHIFT;
 451         if (offset >= roundup(plm->len, PAGE_SIZE))
 452                 return VM_FAULT_SIGBUS;
 453
 454         page = vmalloc_to_page(plm->data + offset);
 455         get_page(page);
 456
 457         vmf->page = page;
 458
 459         return 0;
 460 }
 461
 462 static const struct vm_operations_struct sel_mmap_policy_ops = {
 463         .fault = sel_mmap_policy_fault,
 464         .page_mkwrite = sel_mmap_policy_fault,
 465 };
 466
 467 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 468 {
 469         if (vma->vm_flags & VM_SHARED) {
 470                 /* do not allow mprotect to make mapping writable */
 471                 vma->vm_flags &= ~VM_MAYWRITE;
 472
 473                 if (vma->vm_flags & VM_WRITE)
 474                         return -EACCES;
 475         }
 476
 477         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 478         vma->vm_ops = &sel_mmap_policy_ops;
 479
 480         return 0;
 481 }
 482
 483 static const struct file_operations sel_policy_ops = {
 484         .open           = sel_open_policy,
 485         .read           = sel_read_policy,
 486         .mmap           = sel_mmap_policy,
 487         .release        = sel_release_policy,
 488         .llseek         = generic_file_llseek,
 489 };
 490
 491 static ssize_t sel_write_load(struct file *file, const char __user *buf,
 492                               size_t count, loff_t *ppos)
 493
 494 {
 495         ssize_t length;
 496         void *data = NULL;
 497
 498         mutex_lock(&sel_mutex);
 499
 500         length = task_has_security(current, SECURITY__LOAD_POLICY);
 501         if (length)
 502                 goto out;
 503
 504         /* No partial writes. */
 505         length = -EINVAL;
 506         if (*ppos != 0)
 507                 goto out;
 508
 509         length = -EFBIG;
 510         if (count > 64 * 1024 * 1024)
 511                 goto out;
 512
 513         length = -ENOMEM;
 514         data = vmalloc(count);
 515         if (!data)
 516                 goto out;
 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         length = sel_make_bools();
 527         if (length)
 528                 goto out1;
 529
 530         length = sel_make_classes();
 531         if (length)
 532                 goto out1;
 533
 534         length = sel_make_policycap();
 535         if (length)
 536                 goto out1;
 537
 538         length = count;
 539
 540 out1:
 541         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 542                 "policy loaded auid=%u ses=%u",
 543                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
 544                 audit_get_sessionid(current));
 545 out:
 546         mutex_unlock(&sel_mutex);
 547         vfree(data);
 548         return length;
 549 }
 550
 551 static const struct file_operations sel_load_ops = {
 552         .write          = sel_write_load,
 553         .llseek         = generic_file_llseek,
 554 };
 555
 556 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 557 {
 558         char *canon = NULL;
 559         u32 sid, len;
 560         ssize_t length;
 561
 562         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 563         if (length)
 564                 goto out;
 565
 566         length = security_context_to_sid(buf, size, &sid, GFP_KERNEL);
 567         if (length)
 568                 goto out;
 569
 570         length = security_sid_to_context(sid, &canon, &len);
 571         if (length)
 572                 goto out;
 573
 574         length = -ERANGE;
 575         if (len > SIMPLE_TRANSACTION_LIMIT) {
 576                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 577                         "payload max\n", __func__, len);
 578                 goto out;
 579         }
 580
 581         memcpy(buf, canon, len);
 582         length = len;
 583 out:
 584         kfree(canon);
 585         return length;
 586 }
 587
 588 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 589                                      size_t count, loff_t *ppos)
 590 {
 591         char tmpbuf[TMPBUFLEN];
 592         ssize_t length;
 593
 594         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 595         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 596 }
 597
 598 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 599                                       size_t count, loff_t *ppos)
 600 {
 601         char *page;
 602         ssize_t length;
 603         unsigned int new_value;
 604
 605         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 606         if (length)
 607                 return length;
 608
 609         if (count >= PAGE_SIZE)
 610                 return -ENOMEM;
 611
 612         /* No partial writes. */
 613         if (*ppos != 0)
 614                 return -EINVAL;
 615
 616         page = memdup_user_nul(buf, count);
 617         if (IS_ERR(page))
 618                 return PTR_ERR(page);
 619
 620         length = -EINVAL;
 621         if (sscanf(page, "%u", &new_value) != 1)
 622                 goto out;
 623
 624         selinux_checkreqprot = new_value ? 1 : 0;
 625         length = count;
 626 out:
 627         kfree(page);
 628         return length;
 629 }
 630 static const struct file_operations sel_checkreqprot_ops = {
 631         .read           = sel_read_checkreqprot,
 632         .write          = sel_write_checkreqprot,
 633         .llseek         = generic_file_llseek,
 634 };
 635
 636 static ssize_t sel_write_validatetrans(struct file *file,
 637                                         const char __user *buf,
 638                                         size_t count, loff_t *ppos)
 639 {
 640         char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
 641         char *req = NULL;
 642         u32 osid, nsid, tsid;
 643         u16 tclass;
 644         int rc;
 645
 646         rc = task_has_security(current, SECURITY__VALIDATE_TRANS);
 647         if (rc)
 648                 goto out;
 649
 650         rc = -ENOMEM;
 651         if (count >= PAGE_SIZE)
 652                 goto out;
 653
 654         /* No partial writes. */
 655         rc = -EINVAL;
 656         if (*ppos != 0)
 657                 goto out;
 658
 659         rc = -ENOMEM;
 660         req = kzalloc(count + 1, GFP_KERNEL);
 661         if (!req)
 662                 goto out;
 663
 664         rc = -EFAULT;
 665         if (copy_from_user(req, buf, count))
 666                 goto out;
 667
 668         rc = -ENOMEM;
 669         oldcon = kzalloc(count + 1, GFP_KERNEL);
 670         if (!oldcon)
 671                 goto out;
 672
 673         newcon = kzalloc(count + 1, GFP_KERNEL);
 674         if (!newcon)
 675                 goto out;
 676
 677         taskcon = kzalloc(count + 1, GFP_KERNEL);
 678         if (!taskcon)
 679                 goto out;
 680
 681         rc = -EINVAL;
 682         if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
 683                 goto out;
 684
 685         rc = security_context_str_to_sid(oldcon, &osid, GFP_KERNEL);
 686         if (rc)
 687                 goto out;
 688
 689         rc = security_context_str_to_sid(newcon, &nsid, GFP_KERNEL);
 690         if (rc)
 691                 goto out;
 692
 693         rc = security_context_str_to_sid(taskcon, &tsid, GFP_KERNEL);
 694         if (rc)
 695                 goto out;
 696
 697         rc = security_validate_transition_user(osid, nsid, tsid, tclass);
 698         if (!rc)
 699                 rc = count;
 700 out:
 701         kfree(req);
 702         kfree(oldcon);
 703         kfree(newcon);
 704         kfree(taskcon);
 705         return rc;
 706 }
 707
 708 static const struct file_operations sel_transition_ops = {
 709         .write          = sel_write_validatetrans,
 710         .llseek         = generic_file_llseek,
 711 };
 712
 713 /*
 714  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 715  */
 716 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 717 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 718 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 719 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 720 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 721
 722 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 723         [SEL_ACCESS] = sel_write_access,
 724         [SEL_CREATE] = sel_write_create,
 725         [SEL_RELABEL] = sel_write_relabel,
 726         [SEL_USER] = sel_write_user,
 727         [SEL_MEMBER] = sel_write_member,
 728         [SEL_CONTEXT] = sel_write_context,
 729 };
 730
 731 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 732 {
 733         ino_t ino = file_inode(file)->i_ino;
 734         char *data;
 735         ssize_t rv;
 736
 737         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 738                 return -EINVAL;
 739
 740         data = simple_transaction_get(file, buf, size);
 741         if (IS_ERR(data))
 742                 return PTR_ERR(data);
 743
 744         rv = write_op[ino](file, data, size);
 745         if (rv > 0) {
 746                 simple_transaction_set(file, rv);
 747                 rv = size;
 748         }
 749         return rv;
 750 }
 751
 752 static const struct file_operations transaction_ops = {
 753         .write          = selinux_transaction_write,
 754         .read           = simple_transaction_read,
 755         .release        = simple_transaction_release,
 756         .llseek         = generic_file_llseek,
 757 };
 758
 759 /*
 760  * payload - write methods
 761  * If the method has a response, the response should be put in buf,
 762  * and the length returned.  Otherwise return 0 or and -error.
 763  */
 764
 765 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 766 {
 767         char *scon = NULL, *tcon = NULL;
 768         u32 ssid, tsid;
 769         u16 tclass;
 770         struct av_decision avd;
 771         ssize_t length;
 772
 773         length = task_has_security(current, SECURITY__COMPUTE_AV);
 774         if (length)
 775                 goto out;
 776
 777         length = -ENOMEM;
 778         scon = kzalloc(size + 1, GFP_KERNEL);
 779         if (!scon)
 780                 goto out;
 781
 782         length = -ENOMEM;
 783         tcon = kzalloc(size + 1, GFP_KERNEL);
 784         if (!tcon)
 785                 goto out;
 786
 787         length = -EINVAL;
 788         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 789                 goto out;
 790
 791         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 792         if (length)
 793                 goto out;
 794
 795         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 796         if (length)
 797                 goto out;
 798
 799         security_compute_av_user(ssid, tsid, tclass, &avd);
 800
 801         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 802                           "%x %x %x %x %u %x",
 803                           avd.allowed, 0xffffffff,
 804                           avd.auditallow, avd.auditdeny,
 805                           avd.seqno, avd.flags);
 806 out:
 807         kfree(tcon);
 808         kfree(scon);
 809         return length;
 810 }
 811
 812 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 813 {
 814         char *scon = NULL, *tcon = NULL;
 815         char *namebuf = NULL, *objname = NULL;
 816         u32 ssid, tsid, newsid;
 817         u16 tclass;
 818         ssize_t length;
 819         char *newcon = NULL;
 820         u32 len;
 821         int nargs;
 822
 823         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 824         if (length)
 825                 goto out;
 826
 827         length = -ENOMEM;
 828         scon = kzalloc(size + 1, GFP_KERNEL);
 829         if (!scon)
 830                 goto out;
 831
 832         length = -ENOMEM;
 833         tcon = kzalloc(size + 1, GFP_KERNEL);
 834         if (!tcon)
 835                 goto out;
 836
 837         length = -ENOMEM;
 838         namebuf = kzalloc(size + 1, GFP_KERNEL);
 839         if (!namebuf)
 840                 goto out;
 841
 842         length = -EINVAL;
 843         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 844         if (nargs < 3 || nargs > 4)
 845                 goto out;
 846         if (nargs == 4) {
 847                 /*
 848                  * If and when the name of new object to be queried contains
 849                  * either whitespace or multibyte characters, they shall be
 850                  * encoded based on the percentage-encoding rule.
 851                  * If not encoded, the sscanf logic picks up only left-half
 852                  * of the supplied name; splitted by a whitespace unexpectedly.
 853                  */
 854                 char   *r, *w;
 855                 int     c1, c2;
 856
 857                 r = w = namebuf;
 858                 do {
 859                         c1 = *r++;
 860                         if (c1 == '+')
 861                                 c1 = ' ';
 862                         else if (c1 == '%') {
 863                                 c1 = hex_to_bin(*r++);
 864                                 if (c1 < 0)
 865                                         goto out;
 866                                 c2 = hex_to_bin(*r++);
 867                                 if (c2 < 0)
 868                                         goto out;
 869                                 c1 = (c1 << 4) | c2;
 870                         }
 871                         *w++ = c1;
 872                 } while (c1 != '\0');
 873
 874                 objname = namebuf;
 875         }
 876
 877         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 878         if (length)
 879                 goto out;
 880
 881         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 882         if (length)
 883                 goto out;
 884
 885         length = security_transition_sid_user(ssid, tsid, tclass,
 886                                               objname, &newsid);
 887         if (length)
 888                 goto out;
 889
 890         length = security_sid_to_context(newsid, &newcon, &len);
 891         if (length)
 892                 goto out;
 893
 894         length = -ERANGE;
 895         if (len > SIMPLE_TRANSACTION_LIMIT) {
 896                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 897                         "payload max\n", __func__, len);
 898                 goto out;
 899         }
 900
 901         memcpy(buf, newcon, len);
 902         length = len;
 903 out:
 904         kfree(newcon);
 905         kfree(namebuf);
 906         kfree(tcon);
 907         kfree(scon);
 908         return length;
 909 }
 910
 911 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 912 {
 913         char *scon = NULL, *tcon = NULL;
 914         u32 ssid, tsid, newsid;
 915         u16 tclass;
 916         ssize_t length;
 917         char *newcon = NULL;
 918         u32 len;
 919
 920         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 921         if (length)
 922                 goto out;
 923
 924         length = -ENOMEM;
 925         scon = kzalloc(size + 1, GFP_KERNEL);
 926         if (!scon)
 927                 goto out;
 928
 929         length = -ENOMEM;
 930         tcon = kzalloc(size + 1, GFP_KERNEL);
 931         if (!tcon)
 932                 goto out;
 933
 934         length = -EINVAL;
 935         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 936                 goto out;
 937
 938         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 939         if (length)
 940                 goto out;
 941
 942         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 943         if (length)
 944                 goto out;
 945
 946         length = security_change_sid(ssid, tsid, tclass, &newsid);
 947         if (length)
 948                 goto out;
 949
 950         length = security_sid_to_context(newsid, &newcon, &len);
 951         if (length)
 952                 goto out;
 953
 954         length = -ERANGE;
 955         if (len > SIMPLE_TRANSACTION_LIMIT)
 956                 goto out;
 957
 958         memcpy(buf, newcon, len);
 959         length = len;
 960 out:
 961         kfree(newcon);
 962         kfree(tcon);
 963         kfree(scon);
 964         return length;
 965 }
 966
 967 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 968 {
 969         char *con = NULL, *user = NULL, *ptr;
 970         u32 sid, *sids = NULL;
 971         ssize_t length;
 972         char *newcon;
 973         int i, rc;
 974         u32 len, nsids;
 975
 976         length = task_has_security(current, SECURITY__COMPUTE_USER);
 977         if (length)
 978                 goto out;
 979
 980         length = -ENOMEM;
 981         con = kzalloc(size + 1, GFP_KERNEL);
 982         if (!con)
 983                 goto out;
 984
 985         length = -ENOMEM;
 986         user = kzalloc(size + 1, GFP_KERNEL);
 987         if (!user)
 988                 goto out;
 989
 990         length = -EINVAL;
 991         if (sscanf(buf, "%s %s", con, user) != 2)
 992                 goto out;
 993
 994         length = security_context_str_to_sid(con, &sid, GFP_KERNEL);
 995         if (length)
 996                 goto out;
 997
 998         length = security_get_user_sids(sid, user, &sids, &nsids);
 999         if (length)
1000                 goto out;
1001
1002         length = sprintf(buf, "%u", nsids) + 1;
1003         ptr = buf + length;
1004         for (i = 0; i < nsids; i++) {
1005                 rc = security_sid_to_context(sids[i], &newcon, &len);
1006                 if (rc) {
1007                         length = rc;
1008                         goto out;
1009                 }
1010                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
1011                         kfree(newcon);
1012                         length = -ERANGE;
1013                         goto out;
1014                 }
1015                 memcpy(ptr, newcon, len);
1016                 kfree(newcon);
1017                 ptr += len;
1018                 length += len;
1019         }
1020 out:
1021         kfree(sids);
1022         kfree(user);
1023         kfree(con);
1024         return length;
1025 }
1026
1027 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
1028 {
1029         char *scon = NULL, *tcon = NULL;
1030         u32 ssid, tsid, newsid;
1031         u16 tclass;
1032         ssize_t length;
1033         char *newcon = NULL;
1034         u32 len;
1035
1036         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
1037         if (length)
1038                 goto out;
1039
1040         length = -ENOMEM;
1041         scon = kzalloc(size + 1, GFP_KERNEL);
1042         if (!scon)
1043                 goto out;
1044
1045         length = -ENOMEM;
1046         tcon = kzalloc(size + 1, GFP_KERNEL);
1047         if (!tcon)
1048                 goto out;
1049
1050         length = -EINVAL;
1051         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1052                 goto out;
1053
1054         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
1055         if (length)
1056                 goto out;
1057
1058         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
1059         if (length)
1060                 goto out;
1061
1062         length = security_member_sid(ssid, tsid, tclass, &newsid);
1063         if (length)
1064                 goto out;
1065
1066         length = security_sid_to_context(newsid, &newcon, &len);
1067         if (length)
1068                 goto out;
1069
1070         length = -ERANGE;
1071         if (len > SIMPLE_TRANSACTION_LIMIT) {
1072                 printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1073                         "payload max\n", __func__, len);
1074                 goto out;
1075         }
1076
1077         memcpy(buf, newcon, len);
1078         length = len;
1079 out:
1080         kfree(newcon);
1081         kfree(tcon);
1082         kfree(scon);
1083         return length;
1084 }
1085
1086 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1087 {
1088         struct inode *ret = new_inode(sb);
1089
1090         if (ret) {
1091                 ret->i_mode = mode;
1092                 ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
1093         }
1094         return ret;
1095 }
1096
1097 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1098                              size_t count, loff_t *ppos)
1099 {
1100         char *page = NULL;
1101         ssize_t length;
1102         ssize_t ret;
1103         int cur_enforcing;
1104         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1105         const char *name = filep->f_path.dentry->d_name.name;
1106
1107         mutex_lock(&sel_mutex);
1108
1109         ret = -EINVAL;
1110         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1111                 goto out;
1112
1113         ret = -ENOMEM;
1114         page = (char *)get_zeroed_page(GFP_KERNEL);
1115         if (!page)
1116                 goto out;
1117
1118         cur_enforcing = security_get_bool_value(index);
1119         if (cur_enforcing < 0) {
1120                 ret = cur_enforcing;
1121                 goto out;
1122         }
1123         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1124                           bool_pending_values[index]);
1125         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1126 out:
1127         mutex_unlock(&sel_mutex);
1128         free_page((unsigned long)page);
1129         return ret;
1130 }
1131
1132 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1133                               size_t count, loff_t *ppos)
1134 {
1135         char *page = NULL;
1136         ssize_t length;
1137         int new_value;
1138         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1139         const char *name = filep->f_path.dentry->d_name.name;
1140
1141         mutex_lock(&sel_mutex);
1142
1143         length = task_has_security(current, SECURITY__SETBOOL);
1144         if (length)
1145                 goto out;
1146
1147         length = -EINVAL;
1148         if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1149                 goto out;
1150
1151         length = -ENOMEM;
1152         if (count >= PAGE_SIZE)
1153                 goto out;
1154
1155         /* No partial writes. */
1156         length = -EINVAL;
1157         if (*ppos != 0)
1158                 goto out;
1159
1160         page = memdup_user_nul(buf, count);
1161         if (IS_ERR(page)) {
1162                 length = PTR_ERR(page);
1163                 page = NULL;
1164                 goto out;
1165         }
1166
1167         length = -EINVAL;
1168         if (sscanf(page, "%d", &new_value) != 1)
1169                 goto out;
1170
1171         if (new_value)
1172                 new_value = 1;
1173
1174         bool_pending_values[index] = new_value;
1175         length = count;
1176
1177 out:
1178         mutex_unlock(&sel_mutex);
1179         kfree(page);
1180         return length;
1181 }
1182
1183 static const struct file_operations sel_bool_ops = {
1184         .read           = sel_read_bool,
1185         .write          = sel_write_bool,
1186         .llseek         = generic_file_llseek,
1187 };
1188
1189 static ssize_t sel_commit_bools_write(struct file *filep,
1190                                       const char __user *buf,
1191                                       size_t count, loff_t *ppos)
1192 {
1193         char *page = NULL;
1194         ssize_t length;
1195         int new_value;
1196
1197         mutex_lock(&sel_mutex);
1198
1199         length = task_has_security(current, SECURITY__SETBOOL);
1200         if (length)
1201                 goto out;
1202
1203         length = -ENOMEM;
1204         if (count >= PAGE_SIZE)
1205                 goto out;
1206
1207         /* No partial writes. */
1208         length = -EINVAL;
1209         if (*ppos != 0)
1210                 goto out;
1211
1212         page = memdup_user_nul(buf, count);
1213         if (IS_ERR(page)) {
1214                 length = PTR_ERR(page);
1215                 page = NULL;
1216                 goto out;
1217         }
1218
1219         length = -EINVAL;
1220         if (sscanf(page, "%d", &new_value) != 1)
1221                 goto out;
1222
1223         length = 0;
1224         if (new_value && bool_pending_values)
1225                 length = security_set_bools(bool_num, bool_pending_values);
1226
1227         if (!length)
1228                 length = count;
1229
1230 out:
1231         mutex_unlock(&sel_mutex);
1232         kfree(page);
1233         return length;
1234 }
1235
1236 static const struct file_operations sel_commit_bools_ops = {
1237         .write          = sel_commit_bools_write,
1238         .llseek         = generic_file_llseek,
1239 };
1240
1241 static void sel_remove_entries(struct dentry *de)
1242 {
1243         d_genocide(de);
1244         shrink_dcache_parent(de);
1245 }
1246
1247 #define BOOL_DIR_NAME "booleans"
1248
1249 static int sel_make_bools(void)
1250 {
1251         int i, ret;
1252         ssize_t len;
1253         struct dentry *dentry = NULL;
1254         struct dentry *dir = bool_dir;
1255         struct inode *inode = NULL;
1256         struct inode_security_struct *isec;
1257         char **names = NULL, *page;
1258         int num;
1259         int *values = NULL;
1260         u32 sid;
1261
1262         /* remove any existing files */
1263         for (i = 0; i < bool_num; i++)
1264                 kfree(bool_pending_names[i]);
1265         kfree(bool_pending_names);
1266         kfree(bool_pending_values);
1267         bool_num = 0;
1268         bool_pending_names = NULL;
1269         bool_pending_values = NULL;
1270
1271         sel_remove_entries(dir);
1272
1273         ret = -ENOMEM;
1274         page = (char *)get_zeroed_page(GFP_KERNEL);
1275         if (!page)
1276                 goto out;
1277
1278         ret = security_get_bools(&num, &names, &values);
1279         if (ret)
1280                 goto out;
1281
1282         for (i = 0; i < num; i++) {
1283                 ret = -ENOMEM;
1284                 dentry = d_alloc_name(dir, names[i]);
1285                 if (!dentry)
1286                         goto out;
1287
1288                 ret = -ENOMEM;
1289                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1290                 if (!inode)
1291                         goto out;
1292
1293                 ret = -ENAMETOOLONG;
1294                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1295                 if (len >= PAGE_SIZE)
1296                         goto out;
1297
1298                 isec = (struct inode_security_struct *)inode->i_security;
1299                 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1300                 if (ret)
1301                         goto out;
1302
1303                 isec->sid = sid;
1304                 isec->initialized = 1;
1305                 inode->i_fop = &sel_bool_ops;
1306                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1307                 d_add(dentry, inode);
1308         }
1309         bool_num = num;
1310         bool_pending_names = names;
1311         bool_pending_values = values;
1312
1313         free_page((unsigned long)page);
1314         return 0;
1315 out:
1316         free_page((unsigned long)page);
1317
1318         if (names) {
1319                 for (i = 0; i < num; i++)
1320                         kfree(names[i]);
1321                 kfree(names);
1322         }
1323         kfree(values);
1324         sel_remove_entries(dir);
1325
1326         return ret;
1327 }
1328
1329 #define NULL_FILE_NAME "null"
1330
1331 struct path selinux_null;
1332
1333 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1334                                             size_t count, loff_t *ppos)
1335 {
1336         char tmpbuf[TMPBUFLEN];
1337         ssize_t length;
1338
1339         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1340         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1341 }
1342
1343 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1344                                              const char __user *buf,
1345                                              size_t count, loff_t *ppos)
1346
1347 {
1348         char *page;
1349         ssize_t ret;
1350         unsigned int new_value;
1351
1352         ret = task_has_security(current, SECURITY__SETSECPARAM);
1353         if (ret)
1354                 return ret;
1355
1356         if (count >= PAGE_SIZE)
1357                 return -ENOMEM;
1358
1359         /* No partial writes. */
1360         if (*ppos != 0)
1361                 return -EINVAL;
1362
1363         page = memdup_user_nul(buf, count);
1364         if (IS_ERR(page))
1365                 return PTR_ERR(page);
1366
1367         ret = -EINVAL;
1368         if (sscanf(page, "%u", &new_value) != 1)
1369                 goto out;
1370
1371         avc_cache_threshold = new_value;
1372
1373         ret = count;
1374 out:
1375         kfree(page);
1376         return ret;
1377 }
1378
1379 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1380                                        size_t count, loff_t *ppos)
1381 {
1382         char *page;
1383         ssize_t length;
1384
1385         page = (char *)__get_free_page(GFP_KERNEL);
1386         if (!page)
1387                 return -ENOMEM;
1388
1389         length = avc_get_hash_stats(page);
1390         if (length >= 0)
1391                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1392         free_page((unsigned long)page);
1393
1394         return length;
1395 }
1396
1397 static const struct file_operations sel_avc_cache_threshold_ops = {
1398         .read           = sel_read_avc_cache_threshold,
1399         .write          = sel_write_avc_cache_threshold,
1400         .llseek         = generic_file_llseek,
1401 };
1402
1403 static const struct file_operations sel_avc_hash_stats_ops = {
1404         .read           = sel_read_avc_hash_stats,
1405         .llseek         = generic_file_llseek,
1406 };
1407
1408 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1409 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1410 {
1411         int cpu;
1412
1413         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1414                 if (!cpu_possible(cpu))
1415                         continue;
1416                 *idx = cpu + 1;
1417                 return &per_cpu(avc_cache_stats, cpu);
1418         }
1419         return NULL;
1420 }
1421
1422 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1423 {
1424         loff_t n = *pos - 1;
1425
1426         if (*pos == 0)
1427                 return SEQ_START_TOKEN;
1428
1429         return sel_avc_get_stat_idx(&n);
1430 }
1431
1432 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1433 {
1434         return sel_avc_get_stat_idx(pos);
1435 }
1436
1437 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1438 {
1439         struct avc_cache_stats *st = v;
1440
1441         if (v == SEQ_START_TOKEN)
1442                 seq_printf(seq, "lookups hits misses allocations reclaims "
1443                            "frees\n");
1444         else {
1445                 unsigned int lookups = st->lookups;
1446                 unsigned int misses = st->misses;
1447                 unsigned int hits = lookups - misses;
1448                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1449                            hits, misses, st->allocations,
1450                            st->reclaims, st->frees);
1451         }
1452         return 0;
1453 }
1454
1455 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1456 { }
1457
1458 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1459         .start          = sel_avc_stats_seq_start,
1460         .next           = sel_avc_stats_seq_next,
1461         .show           = sel_avc_stats_seq_show,
1462         .stop           = sel_avc_stats_seq_stop,
1463 };
1464
1465 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1466 {
1467         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1468 }
1469
1470 static const struct file_operations sel_avc_cache_stats_ops = {
1471         .open           = sel_open_avc_cache_stats,
1472         .read           = seq_read,
1473         .llseek         = seq_lseek,
1474         .release        = seq_release,
1475 };
1476 #endif
1477
1478 static int sel_make_avc_files(struct dentry *dir)
1479 {
1480         int i;
1481         static struct tree_descr files[] = {
1482                 { "cache_threshold",
1483                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1484                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1485 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1486                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1487 #endif
1488         };
1489
1490         for (i = 0; i < ARRAY_SIZE(files); i++) {
1491                 struct inode *inode;
1492                 struct dentry *dentry;
1493
1494                 dentry = d_alloc_name(dir, files[i].name);
1495                 if (!dentry)
1496                         return -ENOMEM;
1497
1498                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1499                 if (!inode)
1500                         return -ENOMEM;
1501
1502                 inode->i_fop = files[i].ops;
1503                 inode->i_ino = ++sel_last_ino;
1504                 d_add(dentry, inode);
1505         }
1506
1507         return 0;
1508 }
1509
1510 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1511                                 size_t count, loff_t *ppos)
1512 {
1513         char *con;
1514         u32 sid, len;
1515         ssize_t ret;
1516
1517         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1518         ret = security_sid_to_context(sid, &con, &len);
1519         if (ret)
1520                 return ret;
1521
1522         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1523         kfree(con);
1524         return ret;
1525 }
1526
1527 static const struct file_operations sel_initcon_ops = {
1528         .read           = sel_read_initcon,
1529         .llseek         = generic_file_llseek,
1530 };
1531
1532 static int sel_make_initcon_files(struct dentry *dir)
1533 {
1534         int i;
1535
1536         for (i = 1; i <= SECINITSID_NUM; i++) {
1537                 struct inode *inode;
1538                 struct dentry *dentry;
1539                 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1540                 if (!dentry)
1541                         return -ENOMEM;
1542
1543                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1544                 if (!inode)
1545                         return -ENOMEM;
1546
1547                 inode->i_fop = &sel_initcon_ops;
1548                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1549                 d_add(dentry, inode);
1550         }
1551
1552         return 0;
1553 }
1554
1555 static inline unsigned long sel_class_to_ino(u16 class)
1556 {
1557         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1558 }
1559
1560 static inline u16 sel_ino_to_class(unsigned long ino)
1561 {
1562         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1563 }
1564
1565 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1566 {
1567         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1568 }
1569
1570 static inline u32 sel_ino_to_perm(unsigned long ino)
1571 {
1572         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1573 }
1574
1575 static ssize_t sel_read_class(struct file *file, char __user *buf,
1576                                 size_t count, loff_t *ppos)
1577 {
1578         unsigned long ino = file_inode(file)->i_ino;
1579         char res[TMPBUFLEN];
1580         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1581         return simple_read_from_buffer(buf, count, ppos, res, len);
1582 }
1583
1584 static const struct file_operations sel_class_ops = {
1585         .read           = sel_read_class,
1586         .llseek         = generic_file_llseek,
1587 };
1588
1589 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1590                                 size_t count, loff_t *ppos)
1591 {
1592         unsigned long ino = file_inode(file)->i_ino;
1593         char res[TMPBUFLEN];
1594         ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1595         return simple_read_from_buffer(buf, count, ppos, res, len);
1596 }
1597
1598 static const struct file_operations sel_perm_ops = {
1599         .read           = sel_read_perm,
1600         .llseek         = generic_file_llseek,
1601 };
1602
1603 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1604                                   size_t count, loff_t *ppos)
1605 {
1606         int value;
1607         char tmpbuf[TMPBUFLEN];
1608         ssize_t length;
1609         unsigned long i_ino = file_inode(file)->i_ino;
1610
1611         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1612         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1613
1614         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1615 }
1616
1617 static const struct file_operations sel_policycap_ops = {
1618         .read           = sel_read_policycap,
1619         .llseek         = generic_file_llseek,
1620 };
1621
1622 static int sel_make_perm_files(char *objclass, int classvalue,
1623                                 struct dentry *dir)
1624 {
1625         int i, rc, nperms;
1626         char **perms;
1627
1628         rc = security_get_permissions(objclass, &perms, &nperms);
1629         if (rc)
1630                 return rc;
1631
1632         for (i = 0; i < nperms; i++) {
1633                 struct inode *inode;
1634                 struct dentry *dentry;
1635
1636                 rc = -ENOMEM;
1637                 dentry = d_alloc_name(dir, perms[i]);
1638                 if (!dentry)
1639                         goto out;
1640
1641                 rc = -ENOMEM;
1642                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1643                 if (!inode)
1644                         goto out;
1645
1646                 inode->i_fop = &sel_perm_ops;
1647                 /* i+1 since perm values are 1-indexed */
1648                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1649                 d_add(dentry, inode);
1650         }
1651         rc = 0;
1652 out:
1653         for (i = 0; i < nperms; i++)
1654                 kfree(perms[i]);
1655         kfree(perms);
1656         return rc;
1657 }
1658
1659 static int sel_make_class_dir_entries(char *classname, int index,
1660                                         struct dentry *dir)
1661 {
1662         struct dentry *dentry = NULL;
1663         struct inode *inode = NULL;
1664         int rc;
1665
1666         dentry = d_alloc_name(dir, "index");
1667         if (!dentry)
1668                 return -ENOMEM;
1669
1670         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1671         if (!inode)
1672                 return -ENOMEM;
1673
1674         inode->i_fop = &sel_class_ops;
1675         inode->i_ino = sel_class_to_ino(index);
1676         d_add(dentry, inode);
1677
1678         dentry = sel_make_dir(dir, "perms", &last_class_ino);
1679         if (IS_ERR(dentry))
1680                 return PTR_ERR(dentry);
1681
1682         rc = sel_make_perm_files(classname, index, dentry);
1683
1684         return rc;
1685 }
1686
1687 static int sel_make_classes(void)
1688 {
1689         int rc, nclasses, i;
1690         char **classes;
1691
1692         /* delete any existing entries */
1693         sel_remove_entries(class_dir);
1694
1695         rc = security_get_classes(&classes, &nclasses);
1696         if (rc)
1697                 return rc;
1698
1699         /* +2 since classes are 1-indexed */
1700         last_class_ino = sel_class_to_ino(nclasses + 2);
1701
1702         for (i = 0; i < nclasses; i++) {
1703                 struct dentry *class_name_dir;
1704
1705                 class_name_dir = sel_make_dir(class_dir, classes[i],
1706                                 &last_class_ino);
1707                 if (IS_ERR(class_name_dir)) {
1708                         rc = PTR_ERR(class_name_dir);
1709                         goto out;
1710                 }
1711
1712                 /* i+1 since class values are 1-indexed */
1713                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1714                                 class_name_dir);
1715                 if (rc)
1716                         goto out;
1717         }
1718         rc = 0;
1719 out:
1720         for (i = 0; i < nclasses; i++)
1721                 kfree(classes[i]);
1722         kfree(classes);
1723         return rc;
1724 }
1725
1726 static int sel_make_policycap(void)
1727 {
1728         unsigned int iter;
1729         struct dentry *dentry = NULL;
1730         struct inode *inode = NULL;
1731
1732         sel_remove_entries(policycap_dir);
1733
1734         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1735                 if (iter < ARRAY_SIZE(policycap_names))
1736                         dentry = d_alloc_name(policycap_dir,
1737                                               policycap_names[iter]);
1738                 else
1739                         dentry = d_alloc_name(policycap_dir, "unknown");
1740
1741                 if (dentry == NULL)
1742                         return -ENOMEM;
1743
1744                 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1745                 if (inode == NULL)
1746                         return -ENOMEM;
1747
1748                 inode->i_fop = &sel_policycap_ops;
1749                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1750                 d_add(dentry, inode);
1751         }
1752
1753         return 0;
1754 }
1755
1756 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1757                         unsigned long *ino)
1758 {
1759         struct dentry *dentry = d_alloc_name(dir, name);
1760         struct inode *inode;
1761
1762         if (!dentry)
1763                 return ERR_PTR(-ENOMEM);
1764
1765         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1766         if (!inode) {
1767                 dput(dentry);
1768                 return ERR_PTR(-ENOMEM);
1769         }
1770
1771         inode->i_op = &simple_dir_inode_operations;
1772         inode->i_fop = &simple_dir_operations;
1773         inode->i_ino = ++(*ino);
1774         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1775         inc_nlink(inode);
1776         d_add(dentry, inode);
1777         /* bump link count on parent directory, too */
1778         inc_nlink(d_inode(dir));
1779
1780         return dentry;
1781 }
1782
1783 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1784 {
1785         int ret;
1786         struct dentry *dentry;
1787         struct inode *inode;
1788         struct inode_security_struct *isec;
1789
1790         static struct tree_descr selinux_files[] = {
1791                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1792                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1793                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1794                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1795                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1796                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1797                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1798                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1799                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1800                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1801                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1802                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1803                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1804                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1805                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1806                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1807                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1808                 [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
1809                                         S_IWUGO},
1810                 /* last one */ {""}
1811         };
1812         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1813         if (ret)
1814                 goto err;
1815
1816         bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1817         if (IS_ERR(bool_dir)) {
1818                 ret = PTR_ERR(bool_dir);
1819                 bool_dir = NULL;
1820                 goto err;
1821         }
1822
1823         ret = -ENOMEM;
1824         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1825         if (!dentry)
1826                 goto err;
1827
1828         ret = -ENOMEM;
1829         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1830         if (!inode)
1831                 goto err;
1832
1833         inode->i_ino = ++sel_last_ino;
1834         isec = (struct inode_security_struct *)inode->i_security;
1835         isec->sid = SECINITSID_DEVNULL;
1836         isec->sclass = SECCLASS_CHR_FILE;
1837         isec->initialized = 1;
1838
1839         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1840         d_add(dentry, inode);
1841         selinux_null.dentry = dentry;
1842
1843         dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1844         if (IS_ERR(dentry)) {
1845                 ret = PTR_ERR(dentry);
1846                 goto err;
1847         }
1848
1849         ret = sel_make_avc_files(dentry);
1850         if (ret)
1851                 goto err;
1852
1853         dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1854         if (IS_ERR(dentry)) {
1855                 ret = PTR_ERR(dentry);
1856                 goto err;
1857         }
1858
1859         ret = sel_make_initcon_files(dentry);
1860         if (ret)
1861                 goto err;
1862
1863         class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1864         if (IS_ERR(class_dir)) {
1865                 ret = PTR_ERR(class_dir);
1866                 class_dir = NULL;
1867                 goto err;
1868         }
1869
1870         policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1871         if (IS_ERR(policycap_dir)) {
1872                 ret = PTR_ERR(policycap_dir);
1873                 policycap_dir = NULL;
1874                 goto err;
1875         }
1876         return 0;
1877 err:
1878         printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1879                 __func__);
1880         return ret;
1881 }
1882
1883 static struct dentry *sel_mount(struct file_system_type *fs_type,
1884                       int flags, const char *dev_name, void *data)
1885 {
1886         return mount_single(fs_type, flags, data, sel_fill_super);
1887 }
1888
1889 static struct file_system_type sel_fs_type = {
1890         .name           = "selinuxfs",
1891         .mount          = sel_mount,
1892         .kill_sb        = kill_litter_super,
1893 };
1894
1895 struct vfsmount *selinuxfs_mount;
1896
1897 static int __init init_sel_fs(void)
1898 {
1899         int err;
1900
1901         if (!selinux_enabled)
1902                 return 0;
1903
1904         err = sysfs_create_mount_point(fs_kobj, "selinux");
1905         if (err)
1906                 return err;
1907
1908         err = register_filesystem(&sel_fs_type);
1909         if (err) {
1910                 sysfs_remove_mount_point(fs_kobj, "selinux");
1911                 return err;
1912         }
1913
1914         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1915         if (IS_ERR(selinuxfs_mount)) {
1916                 printk(KERN_ERR "selinuxfs:  could not mount!\n");
1917                 err = PTR_ERR(selinuxfs_mount);
1918                 selinuxfs_mount = NULL;
1919         }
1920
1921         return err;
1922 }
1923
1924 __initcall(init_sel_fs);
1925
1926 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1927 void exit_sel_fs(void)
1928 {
1929         sysfs_remove_mount_point(fs_kobj, "selinux");
1930         kern_unmount(selinuxfs_mount);
1931         unregister_filesystem(&sel_fs_type);
1932 }
1933 #endif