security/selinux/selinuxfs.c

   1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
   2  *
   3  *      Added conditional policy language extensions
   4  *
   5  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
   6  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
   7  *      This program is free software; you can redistribute it and/or modify
   8  *      it under the terms of the GNU General Public License as published by
   9  *      the Free Software Foundation, version 2.
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/kernel.h>
  14 #include <linux/pagemap.h>
  15 #include <linux/slab.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/fs.h>
  18 #include <linux/init.h>
  19 #include <linux/string.h>
  20 #include <linux/security.h>
  21 #include <linux/major.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/percpu.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/semaphore.h>
  26
  27 /* selinuxfs pseudo filesystem for exporting the security policy API.
  28    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  29
  30 #include "flask.h"
  31 #include "avc.h"
  32 #include "avc_ss.h"
  33 #include "security.h"
  34 #include "objsec.h"
  35 #include "conditional.h"
  36
  37 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  38
  39 static int __init checkreqprot_setup(char *str)
  40 {
  41         selinux_checkreqprot = simple_strtoul(str,NULL,0) ? 1 : 0;
  42         return 1;
  43 }
  44 __setup("checkreqprot=", checkreqprot_setup);
  45
  46
  47 static DECLARE_MUTEX(sel_sem);
  48
  49 /* global data for booleans */
  50 static struct dentry *bool_dir = NULL;
  51 static int bool_num = 0;
  52 static int *bool_pending_values = NULL;
  53
  54 extern void selnl_notify_setenforce(int val);
  55
  56 /* Check whether a task is allowed to use a security operation. */
  57 static int task_has_security(struct task_struct *tsk,
  58                              u32 perms)
  59 {
  60         struct task_security_struct *tsec;
  61
  62         tsec = tsk->security;
  63         if (!tsec)
  64                 return -EACCES;
  65
  66         return avc_has_perm(tsec->sid, SECINITSID_SECURITY,
  67                             SECCLASS_SECURITY, perms, NULL);
  68 }
  69
  70 enum sel_inos {
  71         SEL_ROOT_INO = 2,
  72         SEL_LOAD,       /* load policy */
  73         SEL_ENFORCE,    /* get or set enforcing status */
  74         SEL_CONTEXT,    /* validate context */
  75         SEL_ACCESS,     /* compute access decision */
  76         SEL_CREATE,     /* compute create labeling decision */
  77         SEL_RELABEL,    /* compute relabeling decision */
  78         SEL_USER,       /* compute reachable user contexts */
  79         SEL_POLICYVERS, /* return policy version for this kernel */
  80         SEL_COMMIT_BOOLS, /* commit new boolean values */
  81         SEL_MLS,        /* return if MLS policy is enabled */
  82         SEL_DISABLE,    /* disable SELinux until next reboot */
  83         SEL_AVC,        /* AVC management directory */
  84         SEL_MEMBER,     /* compute polyinstantiation membership decision */
  85         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
  86 };
  87
  88 #define TMPBUFLEN       12
  89 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
  90                                 size_t count, loff_t *ppos)
  91 {
  92         char tmpbuf[TMPBUFLEN];
  93         ssize_t length;
  94
  95         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
  96         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
  97 }
  98
  99 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 100 static ssize_t sel_write_enforce(struct file * file, const char __user * buf,
 101                                  size_t count, loff_t *ppos)
 102
 103 {
 104         char *page;
 105         ssize_t length;
 106         int new_value;
 107
 108         if (count >= PAGE_SIZE)
 109                 return -ENOMEM;
 110         if (*ppos != 0) {
 111                 /* No partial writes. */
 112                 return -EINVAL;
 113         }
 114         page = (char*)get_zeroed_page(GFP_KERNEL);
 115         if (!page)
 116                 return -ENOMEM;
 117         length = -EFAULT;
 118         if (copy_from_user(page, buf, count))
 119                 goto out;
 120
 121         length = -EINVAL;
 122         if (sscanf(page, "%d", &new_value) != 1)
 123                 goto out;
 124
 125         if (new_value != selinux_enforcing) {
 126                 length = task_has_security(current, SECURITY__SETENFORCE);
 127                 if (length)
 128                         goto out;
 129                 selinux_enforcing = new_value;
 130                 if (selinux_enforcing)
 131                         avc_ss_reset(0);
 132                 selnl_notify_setenforce(selinux_enforcing);
 133         }
 134         length = count;
 135 out:
 136         free_page((unsigned long) page);
 137         return length;
 138 }
 139 #else
 140 #define sel_write_enforce NULL
 141 #endif
 142
 143 static struct file_operations sel_enforce_ops = {
 144         .read           = sel_read_enforce,
 145         .write          = sel_write_enforce,
 146 };
 147
 148 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 149 static ssize_t sel_write_disable(struct file * file, const char __user * buf,
 150                                  size_t count, loff_t *ppos)
 151
 152 {
 153         char *page;
 154         ssize_t length;
 155         int new_value;
 156         extern int selinux_disable(void);
 157
 158         if (count >= PAGE_SIZE)
 159                 return -ENOMEM;
 160         if (*ppos != 0) {
 161                 /* No partial writes. */
 162                 return -EINVAL;
 163         }
 164         page = (char*)get_zeroed_page(GFP_KERNEL);
 165         if (!page)
 166                 return -ENOMEM;
 167         length = -EFAULT;
 168         if (copy_from_user(page, buf, count))
 169                 goto out;
 170
 171         length = -EINVAL;
 172         if (sscanf(page, "%d", &new_value) != 1)
 173                 goto out;
 174
 175         if (new_value) {
 176                 length = selinux_disable();
 177                 if (length < 0)
 178                         goto out;
 179         }
 180
 181         length = count;
 182 out:
 183         free_page((unsigned long) page);
 184         return length;
 185 }
 186 #else
 187 #define sel_write_disable NULL
 188 #endif
 189
 190 static struct file_operations sel_disable_ops = {
 191         .write          = sel_write_disable,
 192 };
 193
 194 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 195                                    size_t count, loff_t *ppos)
 196 {
 197         char tmpbuf[TMPBUFLEN];
 198         ssize_t length;
 199
 200         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 201         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 202 }
 203
 204 static struct file_operations sel_policyvers_ops = {
 205         .read           = sel_read_policyvers,
 206 };
 207
 208 /* declaration for sel_write_load */
 209 static int sel_make_bools(void);
 210
 211 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 212                                 size_t count, loff_t *ppos)
 213 {
 214         char tmpbuf[TMPBUFLEN];
 215         ssize_t length;
 216
 217         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
 218         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 219 }
 220
 221 static struct file_operations sel_mls_ops = {
 222         .read           = sel_read_mls,
 223 };
 224
 225 static ssize_t sel_write_load(struct file * file, const char __user * buf,
 226                               size_t count, loff_t *ppos)
 227
 228 {
 229         int ret;
 230         ssize_t length;
 231         void *data = NULL;
 232
 233         down(&sel_sem);
 234
 235         length = task_has_security(current, SECURITY__LOAD_POLICY);
 236         if (length)
 237                 goto out;
 238
 239         if (*ppos != 0) {
 240                 /* No partial writes. */
 241                 length = -EINVAL;
 242                 goto out;
 243         }
 244
 245         if ((count > 64 * 1024 * 1024)
 246             || (data = vmalloc(count)) == NULL) {
 247                 length = -ENOMEM;
 248                 goto out;
 249         }
 250
 251         length = -EFAULT;
 252         if (copy_from_user(data, buf, count) != 0)
 253                 goto out;
 254
 255         length = security_load_policy(data, count);
 256         if (length)
 257                 goto out;
 258
 259         ret = sel_make_bools();
 260         if (ret)
 261                 length = ret;
 262         else
 263                 length = count;
 264 out:
 265         up(&sel_sem);
 266         vfree(data);
 267         return length;
 268 }
 269
 270 static struct file_operations sel_load_ops = {
 271         .write          = sel_write_load,
 272 };
 273
 274 static ssize_t sel_write_context(struct file * file, char *buf, size_t size)
 275 {
 276         char *canon;
 277         u32 sid, len;
 278         ssize_t length;
 279
 280         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 281         if (length)
 282                 return length;
 283
 284         length = security_context_to_sid(buf, size, &sid);
 285         if (length < 0)
 286                 return length;
 287
 288         length = security_sid_to_context(sid, &canon, &len);
 289         if (length < 0)
 290                 return length;
 291
 292         if (len > SIMPLE_TRANSACTION_LIMIT) {
 293                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 294                        "max\n", __FUNCTION__, len);
 295                 length = -ERANGE;
 296                 goto out;
 297         }
 298
 299         memcpy(buf, canon, len);
 300         length = len;
 301 out:
 302         kfree(canon);
 303         return length;
 304 }
 305
 306 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 307                                      size_t count, loff_t *ppos)
 308 {
 309         char tmpbuf[TMPBUFLEN];
 310         ssize_t length;
 311
 312         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 313         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 314 }
 315
 316 static ssize_t sel_write_checkreqprot(struct file * file, const char __user * buf,
 317                                       size_t count, loff_t *ppos)
 318 {
 319         char *page;
 320         ssize_t length;
 321         unsigned int new_value;
 322
 323         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 324         if (length)
 325                 return length;
 326
 327         if (count >= PAGE_SIZE)
 328                 return -ENOMEM;
 329         if (*ppos != 0) {
 330                 /* No partial writes. */
 331                 return -EINVAL;
 332         }
 333         page = (char*)get_zeroed_page(GFP_KERNEL);
 334         if (!page)
 335                 return -ENOMEM;
 336         length = -EFAULT;
 337         if (copy_from_user(page, buf, count))
 338                 goto out;
 339
 340         length = -EINVAL;
 341         if (sscanf(page, "%u", &new_value) != 1)
 342                 goto out;
 343
 344         selinux_checkreqprot = new_value ? 1 : 0;
 345         length = count;
 346 out:
 347         free_page((unsigned long) page);
 348         return length;
 349 }
 350 static struct file_operations sel_checkreqprot_ops = {
 351         .read           = sel_read_checkreqprot,
 352         .write          = sel_write_checkreqprot,
 353 };
 354
 355 /*
 356  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 357  */
 358 static ssize_t sel_write_access(struct file * file, char *buf, size_t size);
 359 static ssize_t sel_write_create(struct file * file, char *buf, size_t size);
 360 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size);
 361 static ssize_t sel_write_user(struct file * file, char *buf, size_t size);
 362 static ssize_t sel_write_member(struct file * file, char *buf, size_t size);
 363
 364 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 365         [SEL_ACCESS] = sel_write_access,
 366         [SEL_CREATE] = sel_write_create,
 367         [SEL_RELABEL] = sel_write_relabel,
 368         [SEL_USER] = sel_write_user,
 369         [SEL_MEMBER] = sel_write_member,
 370         [SEL_CONTEXT] = sel_write_context,
 371 };
 372
 373 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 374 {
 375         ino_t ino =  file->f_dentry->d_inode->i_ino;
 376         char *data;
 377         ssize_t rv;
 378
 379         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 380                 return -EINVAL;
 381
 382         data = simple_transaction_get(file, buf, size);
 383         if (IS_ERR(data))
 384                 return PTR_ERR(data);
 385
 386         rv =  write_op[ino](file, data, size);
 387         if (rv>0) {
 388                 simple_transaction_set(file, rv);
 389                 rv = size;
 390         }
 391         return rv;
 392 }
 393
 394 static struct file_operations transaction_ops = {
 395         .write          = selinux_transaction_write,
 396         .read           = simple_transaction_read,
 397         .release        = simple_transaction_release,
 398 };
 399
 400 /*
 401  * payload - write methods
 402  * If the method has a response, the response should be put in buf,
 403  * and the length returned.  Otherwise return 0 or and -error.
 404  */
 405
 406 static ssize_t sel_write_access(struct file * file, char *buf, size_t size)
 407 {
 408         char *scon, *tcon;
 409         u32 ssid, tsid;
 410         u16 tclass;
 411         u32 req;
 412         struct av_decision avd;
 413         ssize_t length;
 414
 415         length = task_has_security(current, SECURITY__COMPUTE_AV);
 416         if (length)
 417                 return length;
 418
 419         length = -ENOMEM;
 420         scon = kzalloc(size+1, GFP_KERNEL);
 421         if (!scon)
 422                 return length;
 423
 424         tcon = kzalloc(size+1, GFP_KERNEL);
 425         if (!tcon)
 426                 goto out;
 427
 428         length = -EINVAL;
 429         if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
 430                 goto out2;
 431
 432         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 433         if (length < 0)
 434                 goto out2;
 435         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 436         if (length < 0)
 437                 goto out2;
 438
 439         length = security_compute_av(ssid, tsid, tclass, req, &avd);
 440         if (length < 0)
 441                 goto out2;
 442
 443         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 444                           "%x %x %x %x %u",
 445                           avd.allowed, avd.decided,
 446                           avd.auditallow, avd.auditdeny,
 447                           avd.seqno);
 448 out2:
 449         kfree(tcon);
 450 out:
 451         kfree(scon);
 452         return length;
 453 }
 454
 455 static ssize_t sel_write_create(struct file * file, char *buf, size_t size)
 456 {
 457         char *scon, *tcon;
 458         u32 ssid, tsid, newsid;
 459         u16 tclass;
 460         ssize_t length;
 461         char *newcon;
 462         u32 len;
 463
 464         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 465         if (length)
 466                 return length;
 467
 468         length = -ENOMEM;
 469         scon = kzalloc(size+1, GFP_KERNEL);
 470         if (!scon)
 471                 return length;
 472
 473         tcon = kzalloc(size+1, GFP_KERNEL);
 474         if (!tcon)
 475                 goto out;
 476
 477         length = -EINVAL;
 478         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 479                 goto out2;
 480
 481         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 482         if (length < 0)
 483                 goto out2;
 484         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 485         if (length < 0)
 486                 goto out2;
 487
 488         length = security_transition_sid(ssid, tsid, tclass, &newsid);
 489         if (length < 0)
 490                 goto out2;
 491
 492         length = security_sid_to_context(newsid, &newcon, &len);
 493         if (length < 0)
 494                 goto out2;
 495
 496         if (len > SIMPLE_TRANSACTION_LIMIT) {
 497                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 498                        "max\n", __FUNCTION__, len);
 499                 length = -ERANGE;
 500                 goto out3;
 501         }
 502
 503         memcpy(buf, newcon, len);
 504         length = len;
 505 out3:
 506         kfree(newcon);
 507 out2:
 508         kfree(tcon);
 509 out:
 510         kfree(scon);
 511         return length;
 512 }
 513
 514 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size)
 515 {
 516         char *scon, *tcon;
 517         u32 ssid, tsid, newsid;
 518         u16 tclass;
 519         ssize_t length;
 520         char *newcon;
 521         u32 len;
 522
 523         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 524         if (length)
 525                 return length;
 526
 527         length = -ENOMEM;
 528         scon = kzalloc(size+1, GFP_KERNEL);
 529         if (!scon)
 530                 return length;
 531
 532         tcon = kzalloc(size+1, GFP_KERNEL);
 533         if (!tcon)
 534                 goto out;
 535
 536         length = -EINVAL;
 537         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 538                 goto out2;
 539
 540         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 541         if (length < 0)
 542                 goto out2;
 543         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 544         if (length < 0)
 545                 goto out2;
 546
 547         length = security_change_sid(ssid, tsid, tclass, &newsid);
 548         if (length < 0)
 549                 goto out2;
 550
 551         length = security_sid_to_context(newsid, &newcon, &len);
 552         if (length < 0)
 553                 goto out2;
 554
 555         if (len > SIMPLE_TRANSACTION_LIMIT) {
 556                 length = -ERANGE;
 557                 goto out3;
 558         }
 559
 560         memcpy(buf, newcon, len);
 561         length = len;
 562 out3:
 563         kfree(newcon);
 564 out2:
 565         kfree(tcon);
 566 out:
 567         kfree(scon);
 568         return length;
 569 }
 570
 571 static ssize_t sel_write_user(struct file * file, char *buf, size_t size)
 572 {
 573         char *con, *user, *ptr;
 574         u32 sid, *sids;
 575         ssize_t length;
 576         char *newcon;
 577         int i, rc;
 578         u32 len, nsids;
 579
 580         length = task_has_security(current, SECURITY__COMPUTE_USER);
 581         if (length)
 582                 return length;
 583
 584         length = -ENOMEM;
 585         con = kzalloc(size+1, GFP_KERNEL);
 586         if (!con)
 587                 return length;
 588
 589         user = kzalloc(size+1, GFP_KERNEL);
 590         if (!user)
 591                 goto out;
 592
 593         length = -EINVAL;
 594         if (sscanf(buf, "%s %s", con, user) != 2)
 595                 goto out2;
 596
 597         length = security_context_to_sid(con, strlen(con)+1, &sid);
 598         if (length < 0)
 599                 goto out2;
 600
 601         length = security_get_user_sids(sid, user, &sids, &nsids);
 602         if (length < 0)
 603                 goto out2;
 604
 605         length = sprintf(buf, "%u", nsids) + 1;
 606         ptr = buf + length;
 607         for (i = 0; i < nsids; i++) {
 608                 rc = security_sid_to_context(sids[i], &newcon, &len);
 609                 if (rc) {
 610                         length = rc;
 611                         goto out3;
 612                 }
 613                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 614                         kfree(newcon);
 615                         length = -ERANGE;
 616                         goto out3;
 617                 }
 618                 memcpy(ptr, newcon, len);
 619                 kfree(newcon);
 620                 ptr += len;
 621                 length += len;
 622         }
 623 out3:
 624         kfree(sids);
 625 out2:
 626         kfree(user);
 627 out:
 628         kfree(con);
 629         return length;
 630 }
 631
 632 static ssize_t sel_write_member(struct file * file, char *buf, size_t size)
 633 {
 634         char *scon, *tcon;
 635         u32 ssid, tsid, newsid;
 636         u16 tclass;
 637         ssize_t length;
 638         char *newcon;
 639         u32 len;
 640
 641         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 642         if (length)
 643                 return length;
 644
 645         length = -ENOMEM;
 646         scon = kzalloc(size+1, GFP_KERNEL);
 647         if (!scon)
 648                 return length;
 649
 650         tcon = kzalloc(size+1, GFP_KERNEL);
 651         if (!tcon)
 652                 goto out;
 653
 654         length = -EINVAL;
 655         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 656                 goto out2;
 657
 658         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 659         if (length < 0)
 660                 goto out2;
 661         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 662         if (length < 0)
 663                 goto out2;
 664
 665         length = security_member_sid(ssid, tsid, tclass, &newsid);
 666         if (length < 0)
 667                 goto out2;
 668
 669         length = security_sid_to_context(newsid, &newcon, &len);
 670         if (length < 0)
 671                 goto out2;
 672
 673         if (len > SIMPLE_TRANSACTION_LIMIT) {
 674                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 675                        "max\n", __FUNCTION__, len);
 676                 length = -ERANGE;
 677                 goto out3;
 678         }
 679
 680         memcpy(buf, newcon, len);
 681         length = len;
 682 out3:
 683         kfree(newcon);
 684 out2:
 685         kfree(tcon);
 686 out:
 687         kfree(scon);
 688         return length;
 689 }
 690
 691 static struct inode *sel_make_inode(struct super_block *sb, int mode)
 692 {
 693         struct inode *ret = new_inode(sb);
 694
 695         if (ret) {
 696                 ret->i_mode = mode;
 697                 ret->i_uid = ret->i_gid = 0;
 698                 ret->i_blksize = PAGE_CACHE_SIZE;
 699                 ret->i_blocks = 0;
 700                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
 701         }
 702         return ret;
 703 }
 704
 705 #define BOOL_INO_OFFSET 30
 706
 707 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 708                              size_t count, loff_t *ppos)
 709 {
 710         char *page = NULL;
 711         ssize_t length;
 712         ssize_t end;
 713         ssize_t ret;
 714         int cur_enforcing;
 715         struct inode *inode;
 716
 717         down(&sel_sem);
 718
 719         ret = -EFAULT;
 720
 721         /* check to see if this file has been deleted */
 722         if (!filep->f_op)
 723                 goto out;
 724
 725         if (count > PAGE_SIZE) {
 726                 ret = -EINVAL;
 727                 goto out;
 728         }
 729         if (!(page = (char*)get_zeroed_page(GFP_KERNEL))) {
 730                 ret = -ENOMEM;
 731                 goto out;
 732         }
 733
 734         inode = filep->f_dentry->d_inode;
 735         cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
 736         if (cur_enforcing < 0) {
 737                 ret = cur_enforcing;
 738                 goto out;
 739         }
 740
 741         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
 742                           bool_pending_values[inode->i_ino - BOOL_INO_OFFSET]);
 743         if (length < 0) {
 744                 ret = length;
 745                 goto out;
 746         }
 747
 748         if (*ppos >= length) {
 749                 ret = 0;
 750                 goto out;
 751         }
 752         if (count + *ppos > length)
 753                 count = length - *ppos;
 754         end = count + *ppos;
 755         if (copy_to_user(buf, (char *) page + *ppos, count)) {
 756                 ret = -EFAULT;
 757                 goto out;
 758         }
 759         *ppos = end;
 760         ret = count;
 761 out:
 762         up(&sel_sem);
 763         if (page)
 764                 free_page((unsigned long)page);
 765         return ret;
 766 }
 767
 768 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 769                               size_t count, loff_t *ppos)
 770 {
 771         char *page = NULL;
 772         ssize_t length = -EFAULT;
 773         int new_value;
 774         struct inode *inode;
 775
 776         down(&sel_sem);
 777
 778         length = task_has_security(current, SECURITY__SETBOOL);
 779         if (length)
 780                 goto out;
 781
 782         /* check to see if this file has been deleted */
 783         if (!filep->f_op)
 784                 goto out;
 785
 786         if (count >= PAGE_SIZE) {
 787                 length = -ENOMEM;
 788                 goto out;
 789         }
 790         if (*ppos != 0) {
 791                 /* No partial writes. */
 792                 goto out;
 793         }
 794         page = (char*)get_zeroed_page(GFP_KERNEL);
 795         if (!page) {
 796                 length = -ENOMEM;
 797                 goto out;
 798         }
 799
 800         if (copy_from_user(page, buf, count))
 801                 goto out;
 802
 803         length = -EINVAL;
 804         if (sscanf(page, "%d", &new_value) != 1)
 805                 goto out;
 806
 807         if (new_value)
 808                 new_value = 1;
 809
 810         inode = filep->f_dentry->d_inode;
 811         bool_pending_values[inode->i_ino - BOOL_INO_OFFSET] = new_value;
 812         length = count;
 813
 814 out:
 815         up(&sel_sem);
 816         if (page)
 817                 free_page((unsigned long) page);
 818         return length;
 819 }
 820
 821 static struct file_operations sel_bool_ops = {
 822         .read           = sel_read_bool,
 823         .write          = sel_write_bool,
 824 };
 825
 826 static ssize_t sel_commit_bools_write(struct file *filep,
 827                                       const char __user *buf,
 828                                       size_t count, loff_t *ppos)
 829 {
 830         char *page = NULL;
 831         ssize_t length = -EFAULT;
 832         int new_value;
 833
 834         down(&sel_sem);
 835
 836         length = task_has_security(current, SECURITY__SETBOOL);
 837         if (length)
 838                 goto out;
 839
 840         /* check to see if this file has been deleted */
 841         if (!filep->f_op)
 842                 goto out;
 843
 844         if (count >= PAGE_SIZE) {
 845                 length = -ENOMEM;
 846                 goto out;
 847         }
 848         if (*ppos != 0) {
 849                 /* No partial writes. */
 850                 goto out;
 851         }
 852         page = (char*)get_zeroed_page(GFP_KERNEL);
 853         if (!page) {
 854                 length = -ENOMEM;
 855                 goto out;
 856         }
 857
 858         if (copy_from_user(page, buf, count))
 859                 goto out;
 860
 861         length = -EINVAL;
 862         if (sscanf(page, "%d", &new_value) != 1)
 863                 goto out;
 864
 865         if (new_value && bool_pending_values) {
 866                 security_set_bools(bool_num, bool_pending_values);
 867         }
 868
 869         length = count;
 870
 871 out:
 872         up(&sel_sem);
 873         if (page)
 874                 free_page((unsigned long) page);
 875         return length;
 876 }
 877
 878 static struct file_operations sel_commit_bools_ops = {
 879         .write          = sel_commit_bools_write,
 880 };
 881
 882 /* delete booleans - partial revoke() from
 883  * fs/proc/generic.c proc_kill_inodes */
 884 static void sel_remove_bools(struct dentry *de)
 885 {
 886         struct list_head *p, *node;
 887         struct super_block *sb = de->d_sb;
 888
 889         spin_lock(&dcache_lock);
 890         node = de->d_subdirs.next;
 891         while (node != &de->d_subdirs) {
 892                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
 893                 list_del_init(node);
 894
 895                 if (d->d_inode) {
 896                         d = dget_locked(d);
 897                         spin_unlock(&dcache_lock);
 898                         d_delete(d);
 899                         simple_unlink(de->d_inode, d);
 900                         dput(d);
 901                         spin_lock(&dcache_lock);
 902                 }
 903                 node = de->d_subdirs.next;
 904         }
 905
 906         spin_unlock(&dcache_lock);
 907
 908         file_list_lock();
 909         list_for_each(p, &sb->s_files) {
 910                 struct file * filp = list_entry(p, struct file, f_u.fu_list);
 911                 struct dentry * dentry = filp->f_dentry;
 912
 913                 if (dentry->d_parent != de) {
 914                         continue;
 915                 }
 916                 filp->f_op = NULL;
 917         }
 918         file_list_unlock();
 919 }
 920
 921 #define BOOL_DIR_NAME "booleans"
 922
 923 static int sel_make_bools(void)
 924 {
 925         int i, ret = 0;
 926         ssize_t len;
 927         struct dentry *dentry = NULL;
 928         struct dentry *dir = bool_dir;
 929         struct inode *inode = NULL;
 930         struct inode_security_struct *isec;
 931         char **names = NULL, *page;
 932         int num;
 933         int *values = NULL;
 934         u32 sid;
 935
 936         /* remove any existing files */
 937         kfree(bool_pending_values);
 938         bool_pending_values = NULL;
 939
 940         sel_remove_bools(dir);
 941
 942         if (!(page = (char*)get_zeroed_page(GFP_KERNEL)))
 943                 return -ENOMEM;
 944
 945         ret = security_get_bools(&num, &names, &values);
 946         if (ret != 0)
 947                 goto out;
 948
 949         for (i = 0; i < num; i++) {
 950                 dentry = d_alloc_name(dir, names[i]);
 951                 if (!dentry) {
 952                         ret = -ENOMEM;
 953                         goto err;
 954                 }
 955                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
 956                 if (!inode) {
 957                         ret = -ENOMEM;
 958                         goto err;
 959                 }
 960
 961                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
 962                 if (len < 0) {
 963                         ret = -EINVAL;
 964                         goto err;
 965                 } else if (len >= PAGE_SIZE) {
 966                         ret = -ENAMETOOLONG;
 967                         goto err;
 968                 }
 969                 isec = (struct inode_security_struct*)inode->i_security;
 970                 if ((ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid)))
 971                         goto err;
 972                 isec->sid = sid;
 973                 isec->initialized = 1;
 974                 inode->i_fop = &sel_bool_ops;
 975                 inode->i_ino = i + BOOL_INO_OFFSET;
 976                 d_add(dentry, inode);
 977         }
 978         bool_num = num;
 979         bool_pending_values = values;
 980 out:
 981         free_page((unsigned long)page);
 982         if (names) {
 983                 for (i = 0; i < num; i++)
 984                         kfree(names[i]);
 985                 kfree(names);
 986         }
 987         return ret;
 988 err:
 989         kfree(values);
 990         d_genocide(dir);
 991         ret = -ENOMEM;
 992         goto out;
 993 }
 994
 995 #define NULL_FILE_NAME "null"
 996
 997 struct dentry *selinux_null = NULL;
 998
 999 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1000                                             size_t count, loff_t *ppos)
1001 {
1002         char tmpbuf[TMPBUFLEN];
1003         ssize_t length;
1004
1005         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1006         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1007 }
1008
1009 static ssize_t sel_write_avc_cache_threshold(struct file * file,
1010                                              const char __user * buf,
1011                                              size_t count, loff_t *ppos)
1012
1013 {
1014         char *page;
1015         ssize_t ret;
1016         int new_value;
1017
1018         if (count >= PAGE_SIZE) {
1019                 ret = -ENOMEM;
1020                 goto out;
1021         }
1022
1023         if (*ppos != 0) {
1024                 /* No partial writes. */
1025                 ret = -EINVAL;
1026                 goto out;
1027         }
1028
1029         page = (char*)get_zeroed_page(GFP_KERNEL);
1030         if (!page) {
1031                 ret = -ENOMEM;
1032                 goto out;
1033         }
1034
1035         if (copy_from_user(page, buf, count)) {
1036                 ret = -EFAULT;
1037                 goto out_free;
1038         }
1039
1040         if (sscanf(page, "%u", &new_value) != 1) {
1041                 ret = -EINVAL;
1042                 goto out;
1043         }
1044
1045         if (new_value != avc_cache_threshold) {
1046                 ret = task_has_security(current, SECURITY__SETSECPARAM);
1047                 if (ret)
1048                         goto out_free;
1049                 avc_cache_threshold = new_value;
1050         }
1051         ret = count;
1052 out_free:
1053         free_page((unsigned long)page);
1054 out:
1055         return ret;
1056 }
1057
1058 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1059                                        size_t count, loff_t *ppos)
1060 {
1061         char *page;
1062         ssize_t ret = 0;
1063
1064         page = (char *)__get_free_page(GFP_KERNEL);
1065         if (!page) {
1066                 ret = -ENOMEM;
1067                 goto out;
1068         }
1069         ret = avc_get_hash_stats(page);
1070         if (ret >= 0)
1071                 ret = simple_read_from_buffer(buf, count, ppos, page, ret);
1072         free_page((unsigned long)page);
1073 out:
1074         return ret;
1075 }
1076
1077 static struct file_operations sel_avc_cache_threshold_ops = {
1078         .read           = sel_read_avc_cache_threshold,
1079         .write          = sel_write_avc_cache_threshold,
1080 };
1081
1082 static struct file_operations sel_avc_hash_stats_ops = {
1083         .read           = sel_read_avc_hash_stats,
1084 };
1085
1086 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1087 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1088 {
1089         int cpu;
1090
1091         for (cpu = *idx; cpu < NR_CPUS; ++cpu) {
1092                 if (!cpu_possible(cpu))
1093                         continue;
1094                 *idx = cpu + 1;
1095                 return &per_cpu(avc_cache_stats, cpu);
1096         }
1097         return NULL;
1098 }
1099
1100 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1101 {
1102         loff_t n = *pos - 1;
1103
1104         if (*pos == 0)
1105                 return SEQ_START_TOKEN;
1106
1107         return sel_avc_get_stat_idx(&n);
1108 }
1109
1110 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1111 {
1112         return sel_avc_get_stat_idx(pos);
1113 }
1114
1115 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1116 {
1117         struct avc_cache_stats *st = v;
1118
1119         if (v == SEQ_START_TOKEN)
1120                 seq_printf(seq, "lookups hits misses allocations reclaims "
1121                            "frees\n");
1122         else
1123                 seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
1124                            st->hits, st->misses, st->allocations,
1125                            st->reclaims, st->frees);
1126         return 0;
1127 }
1128
1129 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1130 { }
1131
1132 static struct seq_operations sel_avc_cache_stats_seq_ops = {
1133         .start          = sel_avc_stats_seq_start,
1134         .next           = sel_avc_stats_seq_next,
1135         .show           = sel_avc_stats_seq_show,
1136         .stop           = sel_avc_stats_seq_stop,
1137 };
1138
1139 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1140 {
1141         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1142 }
1143
1144 static struct file_operations sel_avc_cache_stats_ops = {
1145         .open           = sel_open_avc_cache_stats,
1146         .read           = seq_read,
1147         .llseek         = seq_lseek,
1148         .release        = seq_release,
1149 };
1150 #endif
1151
1152 static int sel_make_avc_files(struct dentry *dir)
1153 {
1154         int i, ret = 0;
1155         static struct tree_descr files[] = {
1156                 { "cache_threshold",
1157                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1158                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1159 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1160                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1161 #endif
1162         };
1163
1164         for (i = 0; i < ARRAY_SIZE(files); i++) {
1165                 struct inode *inode;
1166                 struct dentry *dentry;
1167
1168                 dentry = d_alloc_name(dir, files[i].name);
1169                 if (!dentry) {
1170                         ret = -ENOMEM;
1171                         goto err;
1172                 }
1173
1174                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1175                 if (!inode) {
1176                         ret = -ENOMEM;
1177                         goto err;
1178                 }
1179                 inode->i_fop = files[i].ops;
1180                 d_add(dentry, inode);
1181         }
1182 out:
1183         return ret;
1184 err:
1185         d_genocide(dir);
1186         goto out;
1187 }
1188
1189 static int sel_make_dir(struct super_block *sb, struct dentry *dentry)
1190 {
1191         int ret = 0;
1192         struct inode *inode;
1193
1194         inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1195         if (!inode) {
1196                 ret = -ENOMEM;
1197                 goto out;
1198         }
1199         inode->i_op = &simple_dir_inode_operations;
1200         inode->i_fop = &simple_dir_operations;
1201         d_add(dentry, inode);
1202 out:
1203         return ret;
1204 }
1205
1206 static int sel_fill_super(struct super_block * sb, void * data, int silent)
1207 {
1208         int ret;
1209         struct dentry *dentry;
1210         struct inode *inode;
1211         struct inode_security_struct *isec;
1212
1213         static struct tree_descr selinux_files[] = {
1214                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1215                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1216                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1217                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1218                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1219                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1220                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1221                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1222                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1223                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1224                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1225                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1226                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1227                 /* last one */ {""}
1228         };
1229         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1230         if (ret)
1231                 return ret;
1232
1233         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1234         if (!dentry)
1235                 return -ENOMEM;
1236
1237         inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1238         if (!inode)
1239                 goto out;
1240         inode->i_op = &simple_dir_inode_operations;
1241         inode->i_fop = &simple_dir_operations;
1242         d_add(dentry, inode);
1243         bool_dir = dentry;
1244         ret = sel_make_bools();
1245         if (ret)
1246                 goto out;
1247
1248         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1249         if (!dentry)
1250                 return -ENOMEM;
1251
1252         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1253         if (!inode)
1254                 goto out;
1255         isec = (struct inode_security_struct*)inode->i_security;
1256         isec->sid = SECINITSID_DEVNULL;
1257         isec->sclass = SECCLASS_CHR_FILE;
1258         isec->initialized = 1;
1259
1260         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1261         d_add(dentry, inode);
1262         selinux_null = dentry;
1263
1264         dentry = d_alloc_name(sb->s_root, "avc");
1265         if (!dentry)
1266                 return -ENOMEM;
1267
1268         ret = sel_make_dir(sb, dentry);
1269         if (ret)
1270                 goto out;
1271
1272         ret = sel_make_avc_files(dentry);
1273         if (ret)
1274                 goto out;
1275
1276         return 0;
1277 out:
1278         dput(dentry);
1279         printk(KERN_ERR "%s:  failed while creating inodes\n", __FUNCTION__);
1280         return -ENOMEM;
1281 }
1282
1283 static struct super_block *sel_get_sb(struct file_system_type *fs_type,
1284                                       int flags, const char *dev_name, void *data)
1285 {
1286         return get_sb_single(fs_type, flags, data, sel_fill_super);
1287 }
1288
1289 static struct file_system_type sel_fs_type = {
1290         .name           = "selinuxfs",
1291         .get_sb         = sel_get_sb,
1292         .kill_sb        = kill_litter_super,
1293 };
1294
1295 struct vfsmount *selinuxfs_mount;
1296
1297 static int __init init_sel_fs(void)
1298 {
1299         int err;
1300
1301         if (!selinux_enabled)
1302                 return 0;
1303         err = register_filesystem(&sel_fs_type);
1304         if (!err) {
1305                 selinuxfs_mount = kern_mount(&sel_fs_type);
1306                 if (IS_ERR(selinuxfs_mount)) {
1307                         printk(KERN_ERR "selinuxfs:  could not mount!\n");
1308                         err = PTR_ERR(selinuxfs_mount);
1309                         selinuxfs_mount = NULL;
1310                 }
1311         }
1312         return err;
1313 }
1314
1315 __initcall(init_sel_fs);
1316
1317 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1318 void exit_sel_fs(void)
1319 {
1320         unregister_filesystem(&sel_fs_type);
1321 }
1322 #endif