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  *      This program is free software; you can redistribute it and/or modify
   7  *      it under the terms of the GNU General Public License as published by
   8  *      the Free Software Foundation, version 2.
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/kernel.h>
  13 #include <linux/pagemap.h>
  14 #include <linux/slab.h>
  15 #include <linux/vmalloc.h>
  16 #include <linux/fs.h>
  17 #include <linux/init.h>
  18 #include <linux/string.h>
  19 #include <linux/security.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/semaphore.h>
  22
  23 /* selinuxfs pseudo filesystem for exporting the security policy API.
  24    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  25
  26 #include "flask.h"
  27 #include "avc.h"
  28 #include "avc_ss.h"
  29 #include "security.h"
  30 #include "objsec.h"
  31 #include "conditional.h"
  32
  33 static DECLARE_MUTEX(sel_sem);
  34
  35 /* global data for booleans */
  36 static struct dentry *bool_dir = NULL;
  37 static int bool_num = 0;
  38 static int *bool_pending_values = NULL;
  39
  40 extern void selnl_notify_setenforce(int val);
  41
  42 /* Check whether a task is allowed to use a security operation. */
  43 int task_has_security(struct task_struct *tsk,
  44                       u32 perms)
  45 {
  46         struct task_security_struct *tsec;
  47
  48         tsec = tsk->security;
  49         if (!tsec)
  50                 return -EACCES;
  51
  52         return avc_has_perm(tsec->sid, SECINITSID_SECURITY,
  53                             SECCLASS_SECURITY, perms, NULL, NULL);
  54 }
  55
  56 enum sel_inos {
  57         SEL_ROOT_INO = 2,
  58         SEL_LOAD,       /* load policy */
  59         SEL_ENFORCE,    /* get or set enforcing status */
  60         SEL_CONTEXT,    /* validate context */
  61         SEL_ACCESS,     /* compute access decision */
  62         SEL_CREATE,     /* compute create labeling decision */
  63         SEL_RELABEL,    /* compute relabeling decision */
  64         SEL_USER,       /* compute reachable user contexts */
  65         SEL_POLICYVERS, /* return policy version for this kernel */
  66         SEL_COMMIT_BOOLS, /* commit new boolean values */
  67         SEL_MLS,        /* return if MLS policy is enabled */
  68         SEL_DISABLE     /* disable SELinux until next reboot */
  69 };
  70
  71 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
  72                                 size_t count, loff_t *ppos)
  73 {
  74         char *page;
  75         ssize_t length;
  76         ssize_t end;
  77
  78         if (count < 0 || count > PAGE_SIZE)
  79                 return -EINVAL;
  80         if (!(page = (char*)__get_free_page(GFP_KERNEL)))
  81                 return -ENOMEM;
  82         memset(page, 0, PAGE_SIZE);
  83
  84         length = scnprintf(page, PAGE_SIZE, "%d", selinux_enforcing);
  85         if (length < 0) {
  86                 free_page((unsigned long)page);
  87                 return length;
  88         }
  89
  90         if (*ppos >= length) {
  91                 free_page((unsigned long)page);
  92                 return 0;
  93         }
  94         if (count + *ppos > length)
  95                 count = length - *ppos;
  96         end = count + *ppos;
  97         if (copy_to_user(buf, (char *) page + *ppos, count)) {
  98                 count = -EFAULT;
  99                 goto out;
 100         }
 101         *ppos = end;
 102 out:
 103         free_page((unsigned long)page);
 104         return count;
 105 }
 106
 107 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 108 static ssize_t sel_write_enforce(struct file * file, const char __user * buf,
 109                                  size_t count, loff_t *ppos)
 110
 111 {
 112         char *page;
 113         ssize_t length;
 114         int new_value;
 115
 116         if (count < 0 || count >= PAGE_SIZE)
 117                 return -ENOMEM;
 118         if (*ppos != 0) {
 119                 /* No partial writes. */
 120                 return -EINVAL;
 121         }
 122         page = (char*)__get_free_page(GFP_KERNEL);
 123         if (!page)
 124                 return -ENOMEM;
 125         memset(page, 0, PAGE_SIZE);
 126         length = -EFAULT;
 127         if (copy_from_user(page, buf, count))
 128                 goto out;
 129
 130         length = -EINVAL;
 131         if (sscanf(page, "%d", &new_value) != 1)
 132                 goto out;
 133
 134         if (new_value != selinux_enforcing) {
 135                 length = task_has_security(current, SECURITY__SETENFORCE);
 136                 if (length)
 137                         goto out;
 138                 selinux_enforcing = new_value;
 139                 if (selinux_enforcing)
 140                         avc_ss_reset(0);
 141                 selnl_notify_setenforce(selinux_enforcing);
 142         }
 143         length = count;
 144 out:
 145         free_page((unsigned long) page);
 146         return length;
 147 }
 148 #else
 149 #define sel_write_enforce NULL
 150 #endif
 151
 152 static struct file_operations sel_enforce_ops = {
 153         .read           = sel_read_enforce,
 154         .write          = sel_write_enforce,
 155 };
 156
 157 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 158 static ssize_t sel_write_disable(struct file * file, const char __user * buf,
 159                                  size_t count, loff_t *ppos)
 160
 161 {
 162         char *page;
 163         ssize_t length;
 164         int new_value;
 165         extern int selinux_disable(void);
 166
 167         if (count < 0 || count >= PAGE_SIZE)
 168                 return -ENOMEM;
 169         if (*ppos != 0) {
 170                 /* No partial writes. */
 171                 return -EINVAL;
 172         }
 173         page = (char*)__get_free_page(GFP_KERNEL);
 174         if (!page)
 175                 return -ENOMEM;
 176         memset(page, 0, PAGE_SIZE);
 177         length = -EFAULT;
 178         if (copy_from_user(page, buf, count))
 179                 goto out;
 180
 181         length = -EINVAL;
 182         if (sscanf(page, "%d", &new_value) != 1)
 183                 goto out;
 184
 185         if (new_value) {
 186                 length = selinux_disable();
 187                 if (length < 0)
 188                         goto out;
 189         }
 190
 191         length = count;
 192 out:
 193         free_page((unsigned long) page);
 194         return length;
 195 }
 196 #else
 197 #define sel_write_disable NULL
 198 #endif
 199
 200 static struct file_operations sel_disable_ops = {
 201         .write          = sel_write_disable,
 202 };
 203
 204 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 205                                    size_t count, loff_t *ppos)
 206 {
 207         char *page;
 208         ssize_t length;
 209         ssize_t end;
 210
 211         if (count < 0 || count > PAGE_SIZE)
 212                 return -EINVAL;
 213         if (!(page = (char*)__get_free_page(GFP_KERNEL)))
 214                 return -ENOMEM;
 215         memset(page, 0, PAGE_SIZE);
 216
 217         length = scnprintf(page, PAGE_SIZE, "%u", POLICYDB_VERSION_MAX);
 218         if (length < 0) {
 219                 free_page((unsigned long)page);
 220                 return length;
 221         }
 222
 223         if (*ppos >= length) {
 224                 free_page((unsigned long)page);
 225                 return 0;
 226         }
 227         if (count + *ppos > length)
 228                 count = length - *ppos;
 229         end = count + *ppos;
 230         if (copy_to_user(buf, (char *) page + *ppos, count)) {
 231                 count = -EFAULT;
 232                 goto out;
 233         }
 234         *ppos = end;
 235 out:
 236         free_page((unsigned long)page);
 237         return count;
 238 }
 239
 240 static struct file_operations sel_policyvers_ops = {
 241         .read           = sel_read_policyvers,
 242 };
 243
 244 /* declaration for sel_write_load */
 245 static int sel_make_bools(void);
 246
 247 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 248                                 size_t count, loff_t *ppos)
 249 {
 250         char *page;
 251         ssize_t length;
 252         ssize_t end;
 253
 254         if (count < 0 || count > PAGE_SIZE)
 255                 return -EINVAL;
 256         if (!(page = (char*)__get_free_page(GFP_KERNEL)))
 257                 return -ENOMEM;
 258         memset(page, 0, PAGE_SIZE);
 259
 260         length = scnprintf(page, PAGE_SIZE, "%d", selinux_mls_enabled);
 261         if (length < 0) {
 262                 free_page((unsigned long)page);
 263                 return length;
 264         }
 265
 266         if (*ppos >= length) {
 267                 free_page((unsigned long)page);
 268                 return 0;
 269         }
 270         if (count + *ppos > length)
 271                 count = length - *ppos;
 272         end = count + *ppos;
 273         if (copy_to_user(buf, (char *) page + *ppos, count)) {
 274                 count = -EFAULT;
 275                 goto out;
 276         }
 277         *ppos = end;
 278 out:
 279         free_page((unsigned long)page);
 280         return count;
 281 }
 282
 283 static struct file_operations sel_mls_ops = {
 284         .read           = sel_read_mls,
 285 };
 286
 287 static ssize_t sel_write_load(struct file * file, const char __user * buf,
 288                               size_t count, loff_t *ppos)
 289
 290 {
 291         int ret;
 292         ssize_t length;
 293         void *data = NULL;
 294
 295         down(&sel_sem);
 296
 297         length = task_has_security(current, SECURITY__LOAD_POLICY);
 298         if (length)
 299                 goto out;
 300
 301         if (*ppos != 0) {
 302                 /* No partial writes. */
 303                 length = -EINVAL;
 304                 goto out;
 305         }
 306
 307         if ((count < 0) || (count > 64 * 1024 * 1024)
 308             || (data = vmalloc(count)) == NULL) {
 309                 length = -ENOMEM;
 310                 goto out;
 311         }
 312
 313         length = -EFAULT;
 314         if (copy_from_user(data, buf, count) != 0)
 315                 goto out;
 316
 317         length = security_load_policy(data, count);
 318         if (length)
 319                 goto out;
 320
 321         ret = sel_make_bools();
 322         if (ret)
 323                 length = ret;
 324         else
 325                 length = count;
 326 out:
 327         up(&sel_sem);
 328         vfree(data);
 329         return length;
 330 }
 331
 332 static struct file_operations sel_load_ops = {
 333         .write          = sel_write_load,
 334 };
 335
 336
 337 static ssize_t sel_write_context(struct file * file, const char __user * buf,
 338                                  size_t count, loff_t *ppos)
 339
 340 {
 341         char *page;
 342         u32 sid;
 343         ssize_t length;
 344
 345         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 346         if (length)
 347                 return length;
 348
 349         if (count < 0 || count >= PAGE_SIZE)
 350                 return -ENOMEM;
 351         if (*ppos != 0) {
 352                 /* No partial writes. */
 353                 return -EINVAL;
 354         }
 355         page = (char*)__get_free_page(GFP_KERNEL);
 356         if (!page)
 357                 return -ENOMEM;
 358         memset(page, 0, PAGE_SIZE);
 359         length = -EFAULT;
 360         if (copy_from_user(page, buf, count))
 361                 goto out;
 362
 363         length = security_context_to_sid(page, count, &sid);
 364         if (length < 0)
 365                 goto out;
 366
 367         length = count;
 368 out:
 369         free_page((unsigned long) page);
 370         return length;
 371 }
 372
 373 static struct file_operations sel_context_ops = {
 374         .write          = sel_write_context,
 375 };
 376
 377
 378 /*
 379  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 380  */
 381 static ssize_t sel_write_access(struct file * file, char *buf, size_t size);
 382 static ssize_t sel_write_create(struct file * file, char *buf, size_t size);
 383 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size);
 384 static ssize_t sel_write_user(struct file * file, char *buf, size_t size);
 385
 386 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 387         [SEL_ACCESS] = sel_write_access,
 388         [SEL_CREATE] = sel_write_create,
 389         [SEL_RELABEL] = sel_write_relabel,
 390         [SEL_USER] = sel_write_user,
 391 };
 392
 393 /* an argresp is stored in an allocated page and holds the
 394  * size of the argument or response, along with its content
 395  */
 396 struct argresp {
 397         ssize_t size;
 398         char data[0];
 399 };
 400
 401 #define PAYLOAD_SIZE (PAGE_SIZE - sizeof(struct argresp))
 402
 403 /*
 404  * transaction based IO methods.
 405  * The file expects a single write which triggers the transaction, and then
 406  * possibly a read which collects the result - which is stored in a
 407  * file-local buffer.
 408  */
 409 static ssize_t TA_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 410 {
 411         ino_t ino =  file->f_dentry->d_inode->i_ino;
 412         struct argresp *ar;
 413         ssize_t rv = 0;
 414
 415         if (ino >= sizeof(write_op)/sizeof(write_op[0]) || !write_op[ino])
 416                 return -EINVAL;
 417         if (file->private_data)
 418                 return -EINVAL; /* only one write allowed per open */
 419         if (size > PAYLOAD_SIZE - 1) /* allow one byte for null terminator */
 420                 return -EFBIG;
 421
 422         ar = kmalloc(PAGE_SIZE, GFP_KERNEL);
 423         if (!ar)
 424                 return -ENOMEM;
 425         memset(ar, 0, PAGE_SIZE); /* clear buffer, particularly last byte */
 426         ar->size = 0;
 427         down(&file->f_dentry->d_inode->i_sem);
 428         if (file->private_data)
 429                 rv = -EINVAL;
 430         else
 431                 file->private_data = ar;
 432         up(&file->f_dentry->d_inode->i_sem);
 433         if (rv) {
 434                 kfree(ar);
 435                 return rv;
 436         }
 437         if (copy_from_user(ar->data, buf, size))
 438                 return -EFAULT;
 439
 440         rv =  write_op[ino](file, ar->data, size);
 441         if (rv>0) {
 442                 ar->size = rv;
 443                 rv = size;
 444         }
 445         return rv;
 446 }
 447
 448 static ssize_t TA_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
 449 {
 450         struct argresp *ar;
 451         ssize_t rv = 0;
 452
 453         if (file->private_data == NULL)
 454                 rv = TA_write(file, buf, 0, pos);
 455         if (rv < 0)
 456                 return rv;
 457
 458         ar = file->private_data;
 459         if (!ar)
 460                 return 0;
 461         if (*pos >= ar->size)
 462                 return 0;
 463         if (*pos + size > ar->size)
 464                 size = ar->size - *pos;
 465         if (copy_to_user(buf, ar->data + *pos, size))
 466                 return -EFAULT;
 467         *pos += size;
 468         return size;
 469 }
 470
 471 static int TA_open(struct inode *inode, struct file *file)
 472 {
 473         file->private_data = NULL;
 474         return 0;
 475 }
 476
 477 static int TA_release(struct inode *inode, struct file *file)
 478 {
 479         void *p = file->private_data;
 480         file->private_data = NULL;
 481         kfree(p);
 482         return 0;
 483 }
 484
 485 static struct file_operations transaction_ops = {
 486         .write          = TA_write,
 487         .read           = TA_read,
 488         .open           = TA_open,
 489         .release        = TA_release,
 490 };
 491
 492 /*
 493  * payload - write methods
 494  * If the method has a response, the response should be put in buf,
 495  * and the length returned.  Otherwise return 0 or and -error.
 496  */
 497
 498 static ssize_t sel_write_access(struct file * file, char *buf, size_t size)
 499 {
 500         char *scon, *tcon;
 501         u32 ssid, tsid;
 502         u16 tclass;
 503         u32 req;
 504         struct av_decision avd;
 505         ssize_t length;
 506
 507         length = task_has_security(current, SECURITY__COMPUTE_AV);
 508         if (length)
 509                 return length;
 510
 511         length = -ENOMEM;
 512         scon = kmalloc(size+1, GFP_KERNEL);
 513         if (!scon)
 514                 return length;
 515         memset(scon, 0, size+1);
 516
 517         tcon = kmalloc(size+1, GFP_KERNEL);
 518         if (!tcon)
 519                 goto out;
 520         memset(tcon, 0, size+1);
 521
 522         length = -EINVAL;
 523         if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
 524                 goto out2;
 525
 526         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 527         if (length < 0)
 528                 goto out2;
 529         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 530         if (length < 0)
 531                 goto out2;
 532
 533         length = security_compute_av(ssid, tsid, tclass, req, &avd);
 534         if (length < 0)
 535                 goto out2;
 536
 537         length = scnprintf(buf, PAYLOAD_SIZE, "%x %x %x %x %u",
 538                           avd.allowed, avd.decided,
 539                           avd.auditallow, avd.auditdeny,
 540                           avd.seqno);
 541 out2:
 542         kfree(tcon);
 543 out:
 544         kfree(scon);
 545         return length;
 546 }
 547
 548 static ssize_t sel_write_create(struct file * file, char *buf, size_t size)
 549 {
 550         char *scon, *tcon;
 551         u32 ssid, tsid, newsid;
 552         u16 tclass;
 553         ssize_t length;
 554         char *newcon;
 555         u32 len;
 556
 557         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 558         if (length)
 559                 return length;
 560
 561         length = -ENOMEM;
 562         scon = kmalloc(size+1, GFP_KERNEL);
 563         if (!scon)
 564                 return length;
 565         memset(scon, 0, size+1);
 566
 567         tcon = kmalloc(size+1, GFP_KERNEL);
 568         if (!tcon)
 569                 goto out;
 570         memset(tcon, 0, size+1);
 571
 572         length = -EINVAL;
 573         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 574                 goto out2;
 575
 576         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 577         if (length < 0)
 578                 goto out2;
 579         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 580         if (length < 0)
 581                 goto out2;
 582
 583         length = security_transition_sid(ssid, tsid, tclass, &newsid);
 584         if (length < 0)
 585                 goto out2;
 586
 587         length = security_sid_to_context(newsid, &newcon, &len);
 588         if (length < 0)
 589                 goto out2;
 590
 591         if (len > PAYLOAD_SIZE) {
 592                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 593                        "max\n", __FUNCTION__, len);
 594                 length = -ERANGE;
 595                 goto out3;
 596         }
 597
 598         memcpy(buf, newcon, len);
 599         length = len;
 600 out3:
 601         kfree(newcon);
 602 out2:
 603         kfree(tcon);
 604 out:
 605         kfree(scon);
 606         return length;
 607 }
 608
 609 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size)
 610 {
 611         char *scon, *tcon;
 612         u32 ssid, tsid, newsid;
 613         u16 tclass;
 614         ssize_t length;
 615         char *newcon;
 616         u32 len;
 617
 618         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 619         if (length)
 620                 return length;
 621
 622         length = -ENOMEM;
 623         scon = kmalloc(size+1, GFP_KERNEL);
 624         if (!scon)
 625                 return length;
 626         memset(scon, 0, size+1);
 627
 628         tcon = kmalloc(size+1, GFP_KERNEL);
 629         if (!tcon)
 630                 goto out;
 631         memset(tcon, 0, size+1);
 632
 633         length = -EINVAL;
 634         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 635                 goto out2;
 636
 637         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 638         if (length < 0)
 639                 goto out2;
 640         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 641         if (length < 0)
 642                 goto out2;
 643
 644         length = security_change_sid(ssid, tsid, tclass, &newsid);
 645         if (length < 0)
 646                 goto out2;
 647
 648         length = security_sid_to_context(newsid, &newcon, &len);
 649         if (length < 0)
 650                 goto out2;
 651
 652         if (len > PAYLOAD_SIZE) {
 653                 length = -ERANGE;
 654                 goto out3;
 655         }
 656
 657         memcpy(buf, newcon, len);
 658         length = len;
 659 out3:
 660         kfree(newcon);
 661 out2:
 662         kfree(tcon);
 663 out:
 664         kfree(scon);
 665         return length;
 666 }
 667
 668 static ssize_t sel_write_user(struct file * file, char *buf, size_t size)
 669 {
 670         char *con, *user, *ptr;
 671         u32 sid, *sids;
 672         ssize_t length;
 673         char *newcon;
 674         int i, rc;
 675         u32 len, nsids;
 676
 677         length = task_has_security(current, SECURITY__COMPUTE_USER);
 678         if (length)
 679                 return length;
 680
 681         length = -ENOMEM;
 682         con = kmalloc(size+1, GFP_KERNEL);
 683         if (!con)
 684                 return length;
 685         memset(con, 0, size+1);
 686
 687         user = kmalloc(size+1, GFP_KERNEL);
 688         if (!user)
 689                 goto out;
 690         memset(user, 0, size+1);
 691
 692         length = -EINVAL;
 693         if (sscanf(buf, "%s %s", con, user) != 2)
 694                 goto out2;
 695
 696         length = security_context_to_sid(con, strlen(con)+1, &sid);
 697         if (length < 0)
 698                 goto out2;
 699
 700         length = security_get_user_sids(sid, user, &sids, &nsids);
 701         if (length < 0)
 702                 goto out2;
 703
 704         length = sprintf(buf, "%u", nsids) + 1;
 705         ptr = buf + length;
 706         for (i = 0; i < nsids; i++) {
 707                 rc = security_sid_to_context(sids[i], &newcon, &len);
 708                 if (rc) {
 709                         length = rc;
 710                         goto out3;
 711                 }
 712                 if ((length + len) >= PAYLOAD_SIZE) {
 713                         kfree(newcon);
 714                         length = -ERANGE;
 715                         goto out3;
 716                 }
 717                 memcpy(ptr, newcon, len);
 718                 kfree(newcon);
 719                 ptr += len;
 720                 length += len;
 721         }
 722 out3:
 723         kfree(sids);
 724 out2:
 725         kfree(user);
 726 out:
 727         kfree(con);
 728         return length;
 729 }
 730
 731 static struct inode *sel_make_inode(struct super_block *sb, int mode)
 732 {
 733         struct inode *ret = new_inode(sb);
 734
 735         if (ret) {
 736                 ret->i_mode = mode;
 737                 ret->i_uid = ret->i_gid = 0;
 738                 ret->i_blksize = PAGE_CACHE_SIZE;
 739                 ret->i_blocks = 0;
 740                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
 741         }
 742         return ret;
 743 }
 744
 745 #define BOOL_INO_OFFSET 30
 746
 747 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 748                              size_t count, loff_t *ppos)
 749 {
 750         char *page = NULL;
 751         ssize_t length;
 752         ssize_t end;
 753         ssize_t ret;
 754         int cur_enforcing;
 755         struct inode *inode;
 756
 757         down(&sel_sem);
 758
 759         ret = -EFAULT;
 760
 761         /* check to see if this file has been deleted */
 762         if (!filep->f_op)
 763                 goto out;
 764
 765         if (count < 0 || count > PAGE_SIZE) {
 766                 ret = -EINVAL;
 767                 goto out;
 768         }
 769         if (!(page = (char*)__get_free_page(GFP_KERNEL))) {
 770                 ret = -ENOMEM;
 771                 goto out;
 772         }
 773         memset(page, 0, PAGE_SIZE);
 774
 775         inode = filep->f_dentry->d_inode;
 776         cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
 777         if (cur_enforcing < 0) {
 778                 ret = cur_enforcing;
 779                 goto out;
 780         }
 781
 782         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
 783                           bool_pending_values[inode->i_ino - BOOL_INO_OFFSET]);
 784         if (length < 0) {
 785                 ret = length;
 786                 goto out;
 787         }
 788
 789         if (*ppos >= length) {
 790                 ret = 0;
 791                 goto out;
 792         }
 793         if (count + *ppos > length)
 794                 count = length - *ppos;
 795         end = count + *ppos;
 796         if (copy_to_user(buf, (char *) page + *ppos, count)) {
 797                 ret = -EFAULT;
 798                 goto out;
 799         }
 800         *ppos = end;
 801         ret = count;
 802 out:
 803         up(&sel_sem);
 804         if (page)
 805                 free_page((unsigned long)page);
 806         return ret;
 807 }
 808
 809 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 810                               size_t count, loff_t *ppos)
 811 {
 812         char *page = NULL;
 813         ssize_t length = -EFAULT;
 814         int new_value;
 815         struct inode *inode;
 816
 817         down(&sel_sem);
 818
 819         length = task_has_security(current, SECURITY__SETBOOL);
 820         if (length)
 821                 goto out;
 822
 823         /* check to see if this file has been deleted */
 824         if (!filep->f_op)
 825                 goto out;
 826
 827         if (count < 0 || count >= PAGE_SIZE) {
 828                 length = -ENOMEM;
 829                 goto out;
 830         }
 831         if (*ppos != 0) {
 832                 /* No partial writes. */
 833                 goto out;
 834         }
 835         page = (char*)__get_free_page(GFP_KERNEL);
 836         if (!page) {
 837                 length = -ENOMEM;
 838                 goto out;
 839         }
 840         memset(page, 0, PAGE_SIZE);
 841
 842         if (copy_from_user(page, buf, count))
 843                 goto out;
 844
 845         length = -EINVAL;
 846         if (sscanf(page, "%d", &new_value) != 1)
 847                 goto out;
 848
 849         if (new_value)
 850                 new_value = 1;
 851
 852         inode = filep->f_dentry->d_inode;
 853         bool_pending_values[inode->i_ino - BOOL_INO_OFFSET] = new_value;
 854         length = count;
 855
 856 out:
 857         up(&sel_sem);
 858         if (page)
 859                 free_page((unsigned long) page);
 860         return length;
 861 }
 862
 863 static struct file_operations sel_bool_ops = {
 864         .read           = sel_read_bool,
 865         .write          = sel_write_bool,
 866 };
 867
 868 static ssize_t sel_commit_bools_write(struct file *filep,
 869                                       const char __user *buf,
 870                                       size_t count, loff_t *ppos)
 871 {
 872         char *page = NULL;
 873         ssize_t length = -EFAULT;
 874         int new_value;
 875
 876         down(&sel_sem);
 877
 878         length = task_has_security(current, SECURITY__SETBOOL);
 879         if (length)
 880                 goto out;
 881
 882         /* check to see if this file has been deleted */
 883         if (!filep->f_op)
 884                 goto out;
 885
 886         if (count < 0 || count >= PAGE_SIZE) {
 887                 length = -ENOMEM;
 888                 goto out;
 889         }
 890         if (*ppos != 0) {
 891                 /* No partial writes. */
 892                 goto out;
 893         }
 894         page = (char*)__get_free_page(GFP_KERNEL);
 895         if (!page) {
 896                 length = -ENOMEM;
 897                 goto out;
 898         }
 899
 900         memset(page, 0, PAGE_SIZE);
 901
 902         if (copy_from_user(page, buf, count))
 903                 goto out;
 904
 905         length = -EINVAL;
 906         if (sscanf(page, "%d", &new_value) != 1)
 907                 goto out;
 908
 909         if (new_value) {
 910                 security_set_bools(bool_num, bool_pending_values);
 911         }
 912
 913         length = count;
 914
 915 out:
 916         up(&sel_sem);
 917         if (page)
 918                 free_page((unsigned long) page);
 919         return length;
 920 }
 921
 922 static struct file_operations sel_commit_bools_ops = {
 923         .write          = sel_commit_bools_write,
 924 };
 925
 926 /* delete booleans - partial revoke() from
 927  * fs/proc/generic.c proc_kill_inodes */
 928 static void sel_remove_bools(struct dentry *de)
 929 {
 930         struct list_head *p, *node;
 931         struct super_block *sb = de->d_sb;
 932
 933         spin_lock(&dcache_lock);
 934         node = de->d_subdirs.next;
 935         while (node != &de->d_subdirs) {
 936                 struct dentry *d = list_entry(node, struct dentry, d_child);
 937                 list_del_init(node);
 938
 939                 if (d->d_inode) {
 940                         d = dget_locked(d);
 941                         spin_unlock(&dcache_lock);
 942                         d_delete(d);
 943                         simple_unlink(de->d_inode, d);
 944                         dput(d);
 945                         spin_lock(&dcache_lock);
 946                 }
 947                 node = de->d_subdirs.next;
 948         }
 949
 950         spin_unlock(&dcache_lock);
 951
 952         file_list_lock();
 953         list_for_each(p, &sb->s_files) {
 954                 struct file * filp = list_entry(p, struct file, f_list);
 955                 struct dentry * dentry = filp->f_dentry;
 956
 957                 if (dentry->d_parent != de) {
 958                         continue;
 959                 }
 960                 filp->f_op = NULL;
 961         }
 962         file_list_unlock();
 963 }
 964
 965 #define BOOL_DIR_NAME "booleans"
 966
 967 static int sel_make_bools(void)
 968 {
 969         int i, ret = 0;
 970         ssize_t len;
 971         struct dentry *dentry = NULL;
 972         struct dentry *dir = bool_dir;
 973         struct inode *inode = NULL;
 974         struct inode_security_struct *isec;
 975         struct qstr qname;
 976         char **names = NULL, *page;
 977         int num;
 978         int *values = NULL;
 979         u32 sid;
 980
 981         /* remove any existing files */
 982         if (bool_pending_values)
 983                 kfree(bool_pending_values);
 984
 985         sel_remove_bools(dir);
 986
 987         if (!(page = (char*)__get_free_page(GFP_KERNEL)))
 988                 return -ENOMEM;
 989         memset(page, 0, PAGE_SIZE);
 990
 991         ret = security_get_bools(&num, &names, &values);
 992         if (ret != 0)
 993                 goto out;
 994
 995         for (i = 0; i < num; i++) {
 996                 qname.name = names[i];
 997                 qname.len = strlen(qname.name);
 998                 qname.hash = full_name_hash(qname.name, qname.len);
 999                 dentry = d_alloc(dir, &qname);
1000                 if (!dentry) {
1001                         ret = -ENOMEM;
1002                         goto err;
1003                 }
1004                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1005                 if (!inode) {
1006                         ret = -ENOMEM;
1007                         goto err;
1008                 }
1009
1010                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1011                 if (len < 0) {
1012                         ret = -EINVAL;
1013                         goto err;
1014                 } else if (len >= PAGE_SIZE) {
1015                         ret = -ENAMETOOLONG;
1016                         goto err;
1017                 }
1018                 isec = (struct inode_security_struct*)inode->i_security;
1019                 if ((ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid)))
1020                         goto err;
1021                 isec->sid = sid;
1022                 isec->initialized = 1;
1023                 inode->i_fop = &sel_bool_ops;
1024                 inode->i_ino = i + BOOL_INO_OFFSET;
1025                 d_add(dentry, inode);
1026         }
1027         bool_num = num;
1028         bool_pending_values = values;
1029 out:
1030         free_page((unsigned long)page);
1031         if (names) {
1032                 for (i = 0; i < num; i++) {
1033                         if (names[i])
1034                                 kfree(names[i]);
1035                 }
1036                 kfree(names);
1037         }
1038         return ret;
1039 err:
1040         d_genocide(dir);
1041         ret = -ENOMEM;
1042         goto out;
1043 }
1044
1045 static int sel_fill_super(struct super_block * sb, void * data, int silent)
1046 {
1047         int ret;
1048         struct dentry *dentry;
1049         struct inode *inode;
1050         struct qstr qname;
1051
1052         static struct tree_descr selinux_files[] = {
1053                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1054                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1055                 [SEL_CONTEXT] = {"context", &sel_context_ops, S_IRUGO|S_IWUGO},
1056                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1057                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1058                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1059                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1060                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1061                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1062                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1063                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1064                 /* last one */ {""}
1065         };
1066         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1067         if (ret)
1068                 return ret;
1069
1070         qname.name = BOOL_DIR_NAME;
1071         qname.len = strlen(qname.name);
1072         qname.hash = full_name_hash(qname.name, qname.len);
1073         dentry = d_alloc(sb->s_root, &qname);
1074         if (!dentry)
1075                 return -ENOMEM;
1076
1077         inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1078         if (!inode)
1079                 goto out;
1080         inode->i_op = &simple_dir_inode_operations;
1081         inode->i_fop = &simple_dir_operations;
1082         d_add(dentry, inode);
1083         bool_dir = dentry;
1084         ret = sel_make_bools();
1085         if (ret)
1086                 goto out;
1087
1088         return 0;
1089 out:
1090         dput(dentry);
1091         printk(KERN_ERR "security:      error creating conditional out_dput\n");
1092         return -ENOMEM;
1093 }
1094
1095 static struct super_block *sel_get_sb(struct file_system_type *fs_type,
1096                                       int flags, const char *dev_name, void *data)
1097 {
1098         return get_sb_single(fs_type, flags, data, sel_fill_super);
1099 }
1100
1101 static struct file_system_type sel_fs_type = {
1102         .name           = "selinuxfs",
1103         .get_sb         = sel_get_sb,
1104         .kill_sb        = kill_litter_super,
1105 };
1106
1107 static int __init init_sel_fs(void)
1108 {
1109         return selinux_enabled ? register_filesystem(&sel_fs_type) : 0;
1110 }
1111
1112 __initcall(init_sel_fs);
1113
1114 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1115 void exit_sel_fs(void)
1116 {
1117         unregister_filesystem(&sel_fs_type);
1118 }
1119 #endif