security/selinux/selinuxfs.c

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