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/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/mutex.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 <linux/audit.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/semaphore.h>
  27
  28 /* selinuxfs pseudo filesystem for exporting the security policy API.
  29    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  30
  31 #include "flask.h"
  32 #include "avc.h"
  33 #include "avc_ss.h"
  34 #include "security.h"
  35 #include "objsec.h"
  36 #include "conditional.h"
  37
  38 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  39
  40 #ifdef CONFIG_SECURITY_SELINUX_ENABLE_SECMARK_DEFAULT
  41 #define SELINUX_COMPAT_NET_VALUE 0
  42 #else
  43 #define SELINUX_COMPAT_NET_VALUE 1
  44 #endif
  45
  46 int selinux_compat_net = SELINUX_COMPAT_NET_VALUE;
  47
  48 static int __init checkreqprot_setup(char *str)
  49 {
  50         selinux_checkreqprot = simple_strtoul(str,NULL,0) ? 1 : 0;
  51         return 1;
  52 }
  53 __setup("checkreqprot=", checkreqprot_setup);
  54
  55 static int __init selinux_compat_net_setup(char *str)
  56 {
  57         selinux_compat_net = simple_strtoul(str,NULL,0) ? 1 : 0;
  58         return 1;
  59 }
  60 __setup("selinux_compat_net=", selinux_compat_net_setup);
  61
  62
  63 static DEFINE_MUTEX(sel_mutex);
  64
  65 /* global data for booleans */
  66 static struct dentry *bool_dir = NULL;
  67 static int bool_num = 0;
  68 static int *bool_pending_values = NULL;
  69
  70 extern void selnl_notify_setenforce(int val);
  71
  72 /* Check whether a task is allowed to use a security operation. */
  73 static int task_has_security(struct task_struct *tsk,
  74                              u32 perms)
  75 {
  76         struct task_security_struct *tsec;
  77
  78         tsec = tsk->security;
  79         if (!tsec)
  80                 return -EACCES;
  81
  82         return avc_has_perm(tsec->sid, SECINITSID_SECURITY,
  83                             SECCLASS_SECURITY, perms, NULL);
  84 }
  85
  86 enum sel_inos {
  87         SEL_ROOT_INO = 2,
  88         SEL_LOAD,       /* load policy */
  89         SEL_ENFORCE,    /* get or set enforcing status */
  90         SEL_CONTEXT,    /* validate context */
  91         SEL_ACCESS,     /* compute access decision */
  92         SEL_CREATE,     /* compute create labeling decision */
  93         SEL_RELABEL,    /* compute relabeling decision */
  94         SEL_USER,       /* compute reachable user contexts */
  95         SEL_POLICYVERS, /* return policy version for this kernel */
  96         SEL_COMMIT_BOOLS, /* commit new boolean values */
  97         SEL_MLS,        /* return if MLS policy is enabled */
  98         SEL_DISABLE,    /* disable SELinux until next reboot */
  99         SEL_AVC,        /* AVC management directory */
 100         SEL_MEMBER,     /* compute polyinstantiation membership decision */
 101         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 102         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 103 };
 104
 105 #define TMPBUFLEN       12
 106 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 107                                 size_t count, loff_t *ppos)
 108 {
 109         char tmpbuf[TMPBUFLEN];
 110         ssize_t length;
 111
 112         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 113         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 114 }
 115
 116 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 117 static ssize_t sel_write_enforce(struct file * file, const char __user * buf,
 118                                  size_t count, loff_t *ppos)
 119
 120 {
 121         char *page;
 122         ssize_t length;
 123         int new_value;
 124
 125         if (count >= PAGE_SIZE)
 126                 return -ENOMEM;
 127         if (*ppos != 0) {
 128                 /* No partial writes. */
 129                 return -EINVAL;
 130         }
 131         page = (char*)get_zeroed_page(GFP_KERNEL);
 132         if (!page)
 133                 return -ENOMEM;
 134         length = -EFAULT;
 135         if (copy_from_user(page, buf, count))
 136                 goto out;
 137
 138         length = -EINVAL;
 139         if (sscanf(page, "%d", &new_value) != 1)
 140                 goto out;
 141
 142         if (new_value != selinux_enforcing) {
 143                 length = task_has_security(current, SECURITY__SETENFORCE);
 144                 if (length)
 145                         goto out;
 146                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 147                         "enforcing=%d old_enforcing=%d auid=%u", new_value,
 148                         selinux_enforcing,
 149                         audit_get_loginuid(current->audit_context));
 150                 selinux_enforcing = new_value;
 151                 if (selinux_enforcing)
 152                         avc_ss_reset(0);
 153                 selnl_notify_setenforce(selinux_enforcing);
 154         }
 155         length = count;
 156 out:
 157         free_page((unsigned long) page);
 158         return length;
 159 }
 160 #else
 161 #define sel_write_enforce NULL
 162 #endif
 163
 164 static struct file_operations sel_enforce_ops = {
 165         .read           = sel_read_enforce,
 166         .write          = sel_write_enforce,
 167 };
 168
 169 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 170 static ssize_t sel_write_disable(struct file * file, const char __user * buf,
 171                                  size_t count, loff_t *ppos)
 172
 173 {
 174         char *page;
 175         ssize_t length;
 176         int new_value;
 177         extern int selinux_disable(void);
 178
 179         if (count >= PAGE_SIZE)
 180                 return -ENOMEM;
 181         if (*ppos != 0) {
 182                 /* No partial writes. */
 183                 return -EINVAL;
 184         }
 185         page = (char*)get_zeroed_page(GFP_KERNEL);
 186         if (!page)
 187                 return -ENOMEM;
 188         length = -EFAULT;
 189         if (copy_from_user(page, buf, count))
 190                 goto out;
 191
 192         length = -EINVAL;
 193         if (sscanf(page, "%d", &new_value) != 1)
 194                 goto out;
 195
 196         if (new_value) {
 197                 length = selinux_disable();
 198                 if (length < 0)
 199                         goto out;
 200                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 201                         "selinux=0 auid=%u",
 202                         audit_get_loginuid(current->audit_context));
 203         }
 204
 205         length = count;
 206 out:
 207         free_page((unsigned long) page);
 208         return length;
 209 }
 210 #else
 211 #define sel_write_disable NULL
 212 #endif
 213
 214 static struct file_operations sel_disable_ops = {
 215         .write          = sel_write_disable,
 216 };
 217
 218 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 219                                    size_t count, loff_t *ppos)
 220 {
 221         char tmpbuf[TMPBUFLEN];
 222         ssize_t length;
 223
 224         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 225         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 226 }
 227
 228 static struct file_operations sel_policyvers_ops = {
 229         .read           = sel_read_policyvers,
 230 };
 231
 232 /* declaration for sel_write_load */
 233 static int sel_make_bools(void);
 234
 235 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 236                                 size_t count, loff_t *ppos)
 237 {
 238         char tmpbuf[TMPBUFLEN];
 239         ssize_t length;
 240
 241         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
 242         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 243 }
 244
 245 static struct file_operations sel_mls_ops = {
 246         .read           = sel_read_mls,
 247 };
 248
 249 static ssize_t sel_write_load(struct file * file, const char __user * buf,
 250                               size_t count, loff_t *ppos)
 251
 252 {
 253         int ret;
 254         ssize_t length;
 255         void *data = NULL;
 256
 257         mutex_lock(&sel_mutex);
 258
 259         length = task_has_security(current, SECURITY__LOAD_POLICY);
 260         if (length)
 261                 goto out;
 262
 263         if (*ppos != 0) {
 264                 /* No partial writes. */
 265                 length = -EINVAL;
 266                 goto out;
 267         }
 268
 269         if ((count > 64 * 1024 * 1024)
 270             || (data = vmalloc(count)) == NULL) {
 271                 length = -ENOMEM;
 272                 goto out;
 273         }
 274
 275         length = -EFAULT;
 276         if (copy_from_user(data, buf, count) != 0)
 277                 goto out;
 278
 279         length = security_load_policy(data, count);
 280         if (length)
 281                 goto out;
 282
 283         ret = sel_make_bools();
 284         if (ret)
 285                 length = ret;
 286         else
 287                 length = count;
 288         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 289                 "policy loaded auid=%u",
 290                 audit_get_loginuid(current->audit_context));
 291 out:
 292         mutex_unlock(&sel_mutex);
 293         vfree(data);
 294         return length;
 295 }
 296
 297 static struct file_operations sel_load_ops = {
 298         .write          = sel_write_load,
 299 };
 300
 301 static ssize_t sel_write_context(struct file * file, char *buf, size_t size)
 302 {
 303         char *canon;
 304         u32 sid, len;
 305         ssize_t length;
 306
 307         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 308         if (length)
 309                 return length;
 310
 311         length = security_context_to_sid(buf, size, &sid);
 312         if (length < 0)
 313                 return length;
 314
 315         length = security_sid_to_context(sid, &canon, &len);
 316         if (length < 0)
 317                 return length;
 318
 319         if (len > SIMPLE_TRANSACTION_LIMIT) {
 320                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 321                        "max\n", __FUNCTION__, len);
 322                 length = -ERANGE;
 323                 goto out;
 324         }
 325
 326         memcpy(buf, canon, len);
 327         length = len;
 328 out:
 329         kfree(canon);
 330         return length;
 331 }
 332
 333 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 334                                      size_t count, loff_t *ppos)
 335 {
 336         char tmpbuf[TMPBUFLEN];
 337         ssize_t length;
 338
 339         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 340         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 341 }
 342
 343 static ssize_t sel_write_checkreqprot(struct file * file, const char __user * buf,
 344                                       size_t count, loff_t *ppos)
 345 {
 346         char *page;
 347         ssize_t length;
 348         unsigned int new_value;
 349
 350         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 351         if (length)
 352                 return length;
 353
 354         if (count >= PAGE_SIZE)
 355                 return -ENOMEM;
 356         if (*ppos != 0) {
 357                 /* No partial writes. */
 358                 return -EINVAL;
 359         }
 360         page = (char*)get_zeroed_page(GFP_KERNEL);
 361         if (!page)
 362                 return -ENOMEM;
 363         length = -EFAULT;
 364         if (copy_from_user(page, buf, count))
 365                 goto out;
 366
 367         length = -EINVAL;
 368         if (sscanf(page, "%u", &new_value) != 1)
 369                 goto out;
 370
 371         selinux_checkreqprot = new_value ? 1 : 0;
 372         length = count;
 373 out:
 374         free_page((unsigned long) page);
 375         return length;
 376 }
 377 static struct file_operations sel_checkreqprot_ops = {
 378         .read           = sel_read_checkreqprot,
 379         .write          = sel_write_checkreqprot,
 380 };
 381
 382 static ssize_t sel_read_compat_net(struct file *filp, char __user *buf,
 383                                    size_t count, loff_t *ppos)
 384 {
 385         char tmpbuf[TMPBUFLEN];
 386         ssize_t length;
 387
 388         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_compat_net);
 389         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 390 }
 391
 392 static ssize_t sel_write_compat_net(struct file * file, const char __user * buf,
 393                                     size_t count, loff_t *ppos)
 394 {
 395         char *page;
 396         ssize_t length;
 397         int new_value;
 398
 399         length = task_has_security(current, SECURITY__LOAD_POLICY);
 400         if (length)
 401                 return length;
 402
 403         if (count >= PAGE_SIZE)
 404                 return -ENOMEM;
 405         if (*ppos != 0) {
 406                 /* No partial writes. */
 407                 return -EINVAL;
 408         }
 409         page = (char*)get_zeroed_page(GFP_KERNEL);
 410         if (!page)
 411                 return -ENOMEM;
 412         length = -EFAULT;
 413         if (copy_from_user(page, buf, count))
 414                 goto out;
 415
 416         length = -EINVAL;
 417         if (sscanf(page, "%d", &new_value) != 1)
 418                 goto out;
 419
 420         selinux_compat_net = new_value ? 1 : 0;
 421         length = count;
 422 out:
 423         free_page((unsigned long) page);
 424         return length;
 425 }
 426 static struct file_operations sel_compat_net_ops = {
 427         .read           = sel_read_compat_net,
 428         .write          = sel_write_compat_net,
 429 };
 430
 431 /*
 432  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 433  */
 434 static ssize_t sel_write_access(struct file * file, char *buf, size_t size);
 435 static ssize_t sel_write_create(struct file * file, char *buf, size_t size);
 436 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size);
 437 static ssize_t sel_write_user(struct file * file, char *buf, size_t size);
 438 static ssize_t sel_write_member(struct file * file, char *buf, size_t size);
 439
 440 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 441         [SEL_ACCESS] = sel_write_access,
 442         [SEL_CREATE] = sel_write_create,
 443         [SEL_RELABEL] = sel_write_relabel,
 444         [SEL_USER] = sel_write_user,
 445         [SEL_MEMBER] = sel_write_member,
 446         [SEL_CONTEXT] = sel_write_context,
 447 };
 448
 449 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 450 {
 451         ino_t ino =  file->f_dentry->d_inode->i_ino;
 452         char *data;
 453         ssize_t rv;
 454
 455         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 456                 return -EINVAL;
 457
 458         data = simple_transaction_get(file, buf, size);
 459         if (IS_ERR(data))
 460                 return PTR_ERR(data);
 461
 462         rv =  write_op[ino](file, data, size);
 463         if (rv>0) {
 464                 simple_transaction_set(file, rv);
 465                 rv = size;
 466         }
 467         return rv;
 468 }
 469
 470 static struct file_operations transaction_ops = {
 471         .write          = selinux_transaction_write,
 472         .read           = simple_transaction_read,
 473         .release        = simple_transaction_release,
 474 };
 475
 476 /*
 477  * payload - write methods
 478  * If the method has a response, the response should be put in buf,
 479  * and the length returned.  Otherwise return 0 or and -error.
 480  */
 481
 482 static ssize_t sel_write_access(struct file * file, char *buf, size_t size)
 483 {
 484         char *scon, *tcon;
 485         u32 ssid, tsid;
 486         u16 tclass;
 487         u32 req;
 488         struct av_decision avd;
 489         ssize_t length;
 490
 491         length = task_has_security(current, SECURITY__COMPUTE_AV);
 492         if (length)
 493                 return length;
 494
 495         length = -ENOMEM;
 496         scon = kzalloc(size+1, GFP_KERNEL);
 497         if (!scon)
 498                 return length;
 499
 500         tcon = kzalloc(size+1, GFP_KERNEL);
 501         if (!tcon)
 502                 goto out;
 503
 504         length = -EINVAL;
 505         if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
 506                 goto out2;
 507
 508         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 509         if (length < 0)
 510                 goto out2;
 511         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 512         if (length < 0)
 513                 goto out2;
 514
 515         length = security_compute_av(ssid, tsid, tclass, req, &avd);
 516         if (length < 0)
 517                 goto out2;
 518
 519         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 520                           "%x %x %x %x %u",
 521                           avd.allowed, avd.decided,
 522                           avd.auditallow, avd.auditdeny,
 523                           avd.seqno);
 524 out2:
 525         kfree(tcon);
 526 out:
 527         kfree(scon);
 528         return length;
 529 }
 530
 531 static ssize_t sel_write_create(struct file * file, char *buf, size_t size)
 532 {
 533         char *scon, *tcon;
 534         u32 ssid, tsid, newsid;
 535         u16 tclass;
 536         ssize_t length;
 537         char *newcon;
 538         u32 len;
 539
 540         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 541         if (length)
 542                 return length;
 543
 544         length = -ENOMEM;
 545         scon = kzalloc(size+1, GFP_KERNEL);
 546         if (!scon)
 547                 return length;
 548
 549         tcon = kzalloc(size+1, GFP_KERNEL);
 550         if (!tcon)
 551                 goto out;
 552
 553         length = -EINVAL;
 554         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 555                 goto out2;
 556
 557         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 558         if (length < 0)
 559                 goto out2;
 560         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 561         if (length < 0)
 562                 goto out2;
 563
 564         length = security_transition_sid(ssid, tsid, tclass, &newsid);
 565         if (length < 0)
 566                 goto out2;
 567
 568         length = security_sid_to_context(newsid, &newcon, &len);
 569         if (length < 0)
 570                 goto out2;
 571
 572         if (len > SIMPLE_TRANSACTION_LIMIT) {
 573                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 574                        "max\n", __FUNCTION__, len);
 575                 length = -ERANGE;
 576                 goto out3;
 577         }
 578
 579         memcpy(buf, newcon, len);
 580         length = len;
 581 out3:
 582         kfree(newcon);
 583 out2:
 584         kfree(tcon);
 585 out:
 586         kfree(scon);
 587         return length;
 588 }
 589
 590 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size)
 591 {
 592         char *scon, *tcon;
 593         u32 ssid, tsid, newsid;
 594         u16 tclass;
 595         ssize_t length;
 596         char *newcon;
 597         u32 len;
 598
 599         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 600         if (length)
 601                 return length;
 602
 603         length = -ENOMEM;
 604         scon = kzalloc(size+1, GFP_KERNEL);
 605         if (!scon)
 606                 return length;
 607
 608         tcon = kzalloc(size+1, GFP_KERNEL);
 609         if (!tcon)
 610                 goto out;
 611
 612         length = -EINVAL;
 613         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 614                 goto out2;
 615
 616         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 617         if (length < 0)
 618                 goto out2;
 619         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 620         if (length < 0)
 621                 goto out2;
 622
 623         length = security_change_sid(ssid, tsid, tclass, &newsid);
 624         if (length < 0)
 625                 goto out2;
 626
 627         length = security_sid_to_context(newsid, &newcon, &len);
 628         if (length < 0)
 629                 goto out2;
 630
 631         if (len > SIMPLE_TRANSACTION_LIMIT) {
 632                 length = -ERANGE;
 633                 goto out3;
 634         }
 635
 636         memcpy(buf, newcon, len);
 637         length = len;
 638 out3:
 639         kfree(newcon);
 640 out2:
 641         kfree(tcon);
 642 out:
 643         kfree(scon);
 644         return length;
 645 }
 646
 647 static ssize_t sel_write_user(struct file * file, char *buf, size_t size)
 648 {
 649         char *con, *user, *ptr;
 650         u32 sid, *sids;
 651         ssize_t length;
 652         char *newcon;
 653         int i, rc;
 654         u32 len, nsids;
 655
 656         length = task_has_security(current, SECURITY__COMPUTE_USER);
 657         if (length)
 658                 return length;
 659
 660         length = -ENOMEM;
 661         con = kzalloc(size+1, GFP_KERNEL);
 662         if (!con)
 663                 return length;
 664
 665         user = kzalloc(size+1, GFP_KERNEL);
 666         if (!user)
 667                 goto out;
 668
 669         length = -EINVAL;
 670         if (sscanf(buf, "%s %s", con, user) != 2)
 671                 goto out2;
 672
 673         length = security_context_to_sid(con, strlen(con)+1, &sid);
 674         if (length < 0)
 675                 goto out2;
 676
 677         length = security_get_user_sids(sid, user, &sids, &nsids);
 678         if (length < 0)
 679                 goto out2;
 680
 681         length = sprintf(buf, "%u", nsids) + 1;
 682         ptr = buf + length;
 683         for (i = 0; i < nsids; i++) {
 684                 rc = security_sid_to_context(sids[i], &newcon, &len);
 685                 if (rc) {
 686                         length = rc;
 687                         goto out3;
 688                 }
 689                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 690                         kfree(newcon);
 691                         length = -ERANGE;
 692                         goto out3;
 693                 }
 694                 memcpy(ptr, newcon, len);
 695                 kfree(newcon);
 696                 ptr += len;
 697                 length += len;
 698         }
 699 out3:
 700         kfree(sids);
 701 out2:
 702         kfree(user);
 703 out:
 704         kfree(con);
 705         return length;
 706 }
 707
 708 static ssize_t sel_write_member(struct file * file, char *buf, size_t size)
 709 {
 710         char *scon, *tcon;
 711         u32 ssid, tsid, newsid;
 712         u16 tclass;
 713         ssize_t length;
 714         char *newcon;
 715         u32 len;
 716
 717         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 718         if (length)
 719                 return length;
 720
 721         length = -ENOMEM;
 722         scon = kzalloc(size+1, GFP_KERNEL);
 723         if (!scon)
 724                 return length;
 725
 726         tcon = kzalloc(size+1, GFP_KERNEL);
 727         if (!tcon)
 728                 goto out;
 729
 730         length = -EINVAL;
 731         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 732                 goto out2;
 733
 734         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 735         if (length < 0)
 736                 goto out2;
 737         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 738         if (length < 0)
 739                 goto out2;
 740
 741         length = security_member_sid(ssid, tsid, tclass, &newsid);
 742         if (length < 0)
 743                 goto out2;
 744
 745         length = security_sid_to_context(newsid, &newcon, &len);
 746         if (length < 0)
 747                 goto out2;
 748
 749         if (len > SIMPLE_TRANSACTION_LIMIT) {
 750                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 751                        "max\n", __FUNCTION__, len);
 752                 length = -ERANGE;
 753                 goto out3;
 754         }
 755
 756         memcpy(buf, newcon, len);
 757         length = len;
 758 out3:
 759         kfree(newcon);
 760 out2:
 761         kfree(tcon);
 762 out:
 763         kfree(scon);
 764         return length;
 765 }
 766
 767 static struct inode *sel_make_inode(struct super_block *sb, int mode)
 768 {
 769         struct inode *ret = new_inode(sb);
 770
 771         if (ret) {
 772                 ret->i_mode = mode;
 773                 ret->i_uid = ret->i_gid = 0;
 774                 ret->i_blocks = 0;
 775                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
 776         }
 777         return ret;
 778 }
 779
 780 #define BOOL_INO_OFFSET 30
 781
 782 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 783                              size_t count, loff_t *ppos)
 784 {
 785         char *page = NULL;
 786         ssize_t length;
 787         ssize_t ret;
 788         int cur_enforcing;
 789         struct inode *inode;
 790
 791         mutex_lock(&sel_mutex);
 792
 793         ret = -EFAULT;
 794
 795         /* check to see if this file has been deleted */
 796         if (!filep->f_op)
 797                 goto out;
 798
 799         if (count > PAGE_SIZE) {
 800                 ret = -EINVAL;
 801                 goto out;
 802         }
 803         if (!(page = (char*)get_zeroed_page(GFP_KERNEL))) {
 804                 ret = -ENOMEM;
 805                 goto out;
 806         }
 807
 808         inode = filep->f_dentry->d_inode;
 809         cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
 810         if (cur_enforcing < 0) {
 811                 ret = cur_enforcing;
 812                 goto out;
 813         }
 814
 815         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
 816                           bool_pending_values[inode->i_ino - BOOL_INO_OFFSET]);
 817         ret = simple_read_from_buffer(buf, count, ppos, page, length);
 818 out:
 819         mutex_unlock(&sel_mutex);
 820         if (page)
 821                 free_page((unsigned long)page);
 822         return ret;
 823 }
 824
 825 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 826                               size_t count, loff_t *ppos)
 827 {
 828         char *page = NULL;
 829         ssize_t length = -EFAULT;
 830         int new_value;
 831         struct inode *inode;
 832
 833         mutex_lock(&sel_mutex);
 834
 835         length = task_has_security(current, SECURITY__SETBOOL);
 836         if (length)
 837                 goto out;
 838
 839         /* check to see if this file has been deleted */
 840         if (!filep->f_op)
 841                 goto out;
 842
 843         if (count >= PAGE_SIZE) {
 844                 length = -ENOMEM;
 845                 goto out;
 846         }
 847         if (*ppos != 0) {
 848                 /* No partial writes. */
 849                 goto out;
 850         }
 851         page = (char*)get_zeroed_page(GFP_KERNEL);
 852         if (!page) {
 853                 length = -ENOMEM;
 854                 goto out;
 855         }
 856
 857         if (copy_from_user(page, buf, count))
 858                 goto out;
 859
 860         length = -EINVAL;
 861         if (sscanf(page, "%d", &new_value) != 1)
 862                 goto out;
 863
 864         if (new_value)
 865                 new_value = 1;
 866
 867         inode = filep->f_dentry->d_inode;
 868         bool_pending_values[inode->i_ino - BOOL_INO_OFFSET] = new_value;
 869         length = count;
 870
 871 out:
 872         mutex_unlock(&sel_mutex);
 873         if (page)
 874                 free_page((unsigned long) page);
 875         return length;
 876 }
 877
 878 static struct file_operations sel_bool_ops = {
 879         .read           = sel_read_bool,
 880         .write          = sel_write_bool,
 881 };
 882
 883 static ssize_t sel_commit_bools_write(struct file *filep,
 884                                       const char __user *buf,
 885                                       size_t count, loff_t *ppos)
 886 {
 887         char *page = NULL;
 888         ssize_t length = -EFAULT;
 889         int new_value;
 890
 891         mutex_lock(&sel_mutex);
 892
 893         length = task_has_security(current, SECURITY__SETBOOL);
 894         if (length)
 895                 goto out;
 896
 897         /* check to see if this file has been deleted */
 898         if (!filep->f_op)
 899                 goto out;
 900
 901         if (count >= PAGE_SIZE) {
 902                 length = -ENOMEM;
 903                 goto out;
 904         }
 905         if (*ppos != 0) {
 906                 /* No partial writes. */
 907                 goto out;
 908         }
 909         page = (char*)get_zeroed_page(GFP_KERNEL);
 910         if (!page) {
 911                 length = -ENOMEM;
 912                 goto out;
 913         }
 914
 915         if (copy_from_user(page, buf, count))
 916                 goto out;
 917
 918         length = -EINVAL;
 919         if (sscanf(page, "%d", &new_value) != 1)
 920                 goto out;
 921
 922         if (new_value && bool_pending_values) {
 923                 security_set_bools(bool_num, bool_pending_values);
 924         }
 925
 926         length = count;
 927
 928 out:
 929         mutex_unlock(&sel_mutex);
 930         if (page)
 931                 free_page((unsigned long) page);
 932         return length;
 933 }
 934
 935 static struct file_operations sel_commit_bools_ops = {
 936         .write          = sel_commit_bools_write,
 937 };
 938
 939 /* delete booleans - partial revoke() from
 940  * fs/proc/generic.c proc_kill_inodes */
 941 static void sel_remove_bools(struct dentry *de)
 942 {
 943         struct list_head *p, *node;
 944         struct super_block *sb = de->d_sb;
 945
 946         spin_lock(&dcache_lock);
 947         node = de->d_subdirs.next;
 948         while (node != &de->d_subdirs) {
 949                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
 950                 list_del_init(node);
 951
 952                 if (d->d_inode) {
 953                         d = dget_locked(d);
 954                         spin_unlock(&dcache_lock);
 955                         d_delete(d);
 956                         simple_unlink(de->d_inode, d);
 957                         dput(d);
 958                         spin_lock(&dcache_lock);
 959                 }
 960                 node = de->d_subdirs.next;
 961         }
 962
 963         spin_unlock(&dcache_lock);
 964
 965         file_list_lock();
 966         list_for_each(p, &sb->s_files) {
 967                 struct file * filp = list_entry(p, struct file, f_u.fu_list);
 968                 struct dentry * dentry = filp->f_dentry;
 969
 970                 if (dentry->d_parent != de) {
 971                         continue;
 972                 }
 973                 filp->f_op = NULL;
 974         }
 975         file_list_unlock();
 976 }
 977
 978 #define BOOL_DIR_NAME "booleans"
 979
 980 static int sel_make_bools(void)
 981 {
 982         int i, ret = 0;
 983         ssize_t len;
 984         struct dentry *dentry = NULL;
 985         struct dentry *dir = bool_dir;
 986         struct inode *inode = NULL;
 987         struct inode_security_struct *isec;
 988         char **names = NULL, *page;
 989         int num;
 990         int *values = NULL;
 991         u32 sid;
 992
 993         /* remove any existing files */
 994         kfree(bool_pending_values);
 995         bool_pending_values = NULL;
 996
 997         sel_remove_bools(dir);
 998
 999         if (!(page = (char*)get_zeroed_page(GFP_KERNEL)))
1000                 return -ENOMEM;
1001
1002         ret = security_get_bools(&num, &names, &values);
1003         if (ret != 0)
1004                 goto out;
1005
1006         for (i = 0; i < num; i++) {
1007                 dentry = d_alloc_name(dir, names[i]);
1008                 if (!dentry) {
1009                         ret = -ENOMEM;
1010                         goto err;
1011                 }
1012                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1013                 if (!inode) {
1014                         ret = -ENOMEM;
1015                         goto err;
1016                 }
1017
1018                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1019                 if (len < 0) {
1020                         ret = -EINVAL;
1021                         goto err;
1022                 } else if (len >= PAGE_SIZE) {
1023                         ret = -ENAMETOOLONG;
1024                         goto err;
1025                 }
1026                 isec = (struct inode_security_struct*)inode->i_security;
1027                 if ((ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid)))
1028                         goto err;
1029                 isec->sid = sid;
1030                 isec->initialized = 1;
1031                 inode->i_fop = &sel_bool_ops;
1032                 inode->i_ino = i + BOOL_INO_OFFSET;
1033                 d_add(dentry, inode);
1034         }
1035         bool_num = num;
1036         bool_pending_values = values;
1037 out:
1038         free_page((unsigned long)page);
1039         if (names) {
1040                 for (i = 0; i < num; i++)
1041                         kfree(names[i]);
1042                 kfree(names);
1043         }
1044         return ret;
1045 err:
1046         kfree(values);
1047         sel_remove_bools(dir);
1048         ret = -ENOMEM;
1049         goto out;
1050 }
1051
1052 #define NULL_FILE_NAME "null"
1053
1054 struct dentry *selinux_null = NULL;
1055
1056 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1057                                             size_t count, loff_t *ppos)
1058 {
1059         char tmpbuf[TMPBUFLEN];
1060         ssize_t length;
1061
1062         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1063         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1064 }
1065
1066 static ssize_t sel_write_avc_cache_threshold(struct file * file,
1067                                              const char __user * buf,
1068                                              size_t count, loff_t *ppos)
1069
1070 {
1071         char *page;
1072         ssize_t ret;
1073         int new_value;
1074
1075         if (count >= PAGE_SIZE) {
1076                 ret = -ENOMEM;
1077                 goto out;
1078         }
1079
1080         if (*ppos != 0) {
1081                 /* No partial writes. */
1082                 ret = -EINVAL;
1083                 goto out;
1084         }
1085
1086         page = (char*)get_zeroed_page(GFP_KERNEL);
1087         if (!page) {
1088                 ret = -ENOMEM;
1089                 goto out;
1090         }
1091
1092         if (copy_from_user(page, buf, count)) {
1093                 ret = -EFAULT;
1094                 goto out_free;
1095         }
1096
1097         if (sscanf(page, "%u", &new_value) != 1) {
1098                 ret = -EINVAL;
1099                 goto out;
1100         }
1101
1102         if (new_value != avc_cache_threshold) {
1103                 ret = task_has_security(current, SECURITY__SETSECPARAM);
1104                 if (ret)
1105                         goto out_free;
1106                 avc_cache_threshold = new_value;
1107         }
1108         ret = count;
1109 out_free:
1110         free_page((unsigned long)page);
1111 out:
1112         return ret;
1113 }
1114
1115 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1116                                        size_t count, loff_t *ppos)
1117 {
1118         char *page;
1119         ssize_t ret = 0;
1120
1121         page = (char *)__get_free_page(GFP_KERNEL);
1122         if (!page) {
1123                 ret = -ENOMEM;
1124                 goto out;
1125         }
1126         ret = avc_get_hash_stats(page);
1127         if (ret >= 0)
1128                 ret = simple_read_from_buffer(buf, count, ppos, page, ret);
1129         free_page((unsigned long)page);
1130 out:
1131         return ret;
1132 }
1133
1134 static struct file_operations sel_avc_cache_threshold_ops = {
1135         .read           = sel_read_avc_cache_threshold,
1136         .write          = sel_write_avc_cache_threshold,
1137 };
1138
1139 static struct file_operations sel_avc_hash_stats_ops = {
1140         .read           = sel_read_avc_hash_stats,
1141 };
1142
1143 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1144 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1145 {
1146         int cpu;
1147
1148         for (cpu = *idx; cpu < NR_CPUS; ++cpu) {
1149                 if (!cpu_possible(cpu))
1150                         continue;
1151                 *idx = cpu + 1;
1152                 return &per_cpu(avc_cache_stats, cpu);
1153         }
1154         return NULL;
1155 }
1156
1157 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1158 {
1159         loff_t n = *pos - 1;
1160
1161         if (*pos == 0)
1162                 return SEQ_START_TOKEN;
1163
1164         return sel_avc_get_stat_idx(&n);
1165 }
1166
1167 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1168 {
1169         return sel_avc_get_stat_idx(pos);
1170 }
1171
1172 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1173 {
1174         struct avc_cache_stats *st = v;
1175
1176         if (v == SEQ_START_TOKEN)
1177                 seq_printf(seq, "lookups hits misses allocations reclaims "
1178                            "frees\n");
1179         else
1180                 seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
1181                            st->hits, st->misses, st->allocations,
1182                            st->reclaims, st->frees);
1183         return 0;
1184 }
1185
1186 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1187 { }
1188
1189 static struct seq_operations sel_avc_cache_stats_seq_ops = {
1190         .start          = sel_avc_stats_seq_start,
1191         .next           = sel_avc_stats_seq_next,
1192         .show           = sel_avc_stats_seq_show,
1193         .stop           = sel_avc_stats_seq_stop,
1194 };
1195
1196 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1197 {
1198         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1199 }
1200
1201 static struct file_operations sel_avc_cache_stats_ops = {
1202         .open           = sel_open_avc_cache_stats,
1203         .read           = seq_read,
1204         .llseek         = seq_lseek,
1205         .release        = seq_release,
1206 };
1207 #endif
1208
1209 static int sel_make_avc_files(struct dentry *dir)
1210 {
1211         int i, ret = 0;
1212         static struct tree_descr files[] = {
1213                 { "cache_threshold",
1214                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1215                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1216 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1217                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1218 #endif
1219         };
1220
1221         for (i = 0; i < ARRAY_SIZE(files); i++) {
1222                 struct inode *inode;
1223                 struct dentry *dentry;
1224
1225                 dentry = d_alloc_name(dir, files[i].name);
1226                 if (!dentry) {
1227                         ret = -ENOMEM;
1228                         goto out;
1229                 }
1230
1231                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1232                 if (!inode) {
1233                         ret = -ENOMEM;
1234                         goto out;
1235                 }
1236                 inode->i_fop = files[i].ops;
1237                 d_add(dentry, inode);
1238         }
1239 out:
1240         return ret;
1241 }
1242
1243 static int sel_make_dir(struct inode *dir, struct dentry *dentry)
1244 {
1245         int ret = 0;
1246         struct inode *inode;
1247
1248         inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1249         if (!inode) {
1250                 ret = -ENOMEM;
1251                 goto out;
1252         }
1253         inode->i_op = &simple_dir_inode_operations;
1254         inode->i_fop = &simple_dir_operations;
1255         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1256         inode->i_nlink++;
1257         d_add(dentry, inode);
1258         /* bump link count on parent directory, too */
1259         dir->i_nlink++;
1260 out:
1261         return ret;
1262 }
1263
1264 static int sel_fill_super(struct super_block * sb, void * data, int silent)
1265 {
1266         int ret;
1267         struct dentry *dentry;
1268         struct inode *inode, *root_inode;
1269         struct inode_security_struct *isec;
1270
1271         static struct tree_descr selinux_files[] = {
1272                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1273                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1274                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1275                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1276                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1277                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1278                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1279                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1280                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1281                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1282                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1283                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1284                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1285                 [SEL_COMPAT_NET] = {"compat_net", &sel_compat_net_ops, S_IRUGO|S_IWUSR},
1286                 /* last one */ {""}
1287         };
1288         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1289         if (ret)
1290                 goto err;
1291
1292         root_inode = sb->s_root->d_inode;
1293
1294         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1295         if (!dentry) {
1296                 ret = -ENOMEM;
1297                 goto err;
1298         }
1299
1300         ret = sel_make_dir(root_inode, dentry);
1301         if (ret)
1302                 goto err;
1303
1304         bool_dir = dentry;
1305
1306         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1307         if (!dentry) {
1308                 ret = -ENOMEM;
1309                 goto err;
1310         }
1311
1312         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1313         if (!inode) {
1314                 ret = -ENOMEM;
1315                 goto err;
1316         }
1317         isec = (struct inode_security_struct*)inode->i_security;
1318         isec->sid = SECINITSID_DEVNULL;
1319         isec->sclass = SECCLASS_CHR_FILE;
1320         isec->initialized = 1;
1321
1322         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1323         d_add(dentry, inode);
1324         selinux_null = dentry;
1325
1326         dentry = d_alloc_name(sb->s_root, "avc");
1327         if (!dentry) {
1328                 ret = -ENOMEM;
1329                 goto err;
1330         }
1331
1332         ret = sel_make_dir(root_inode, dentry);
1333         if (ret)
1334                 goto err;
1335
1336         ret = sel_make_avc_files(dentry);
1337         if (ret)
1338                 goto err;
1339 out:
1340         return ret;
1341 err:
1342         printk(KERN_ERR "%s:  failed while creating inodes\n", __FUNCTION__);
1343         goto out;
1344 }
1345
1346 static int sel_get_sb(struct file_system_type *fs_type,
1347                       int flags, const char *dev_name, void *data,
1348                       struct vfsmount *mnt)
1349 {
1350         return get_sb_single(fs_type, flags, data, sel_fill_super, mnt);
1351 }
1352
1353 static struct file_system_type sel_fs_type = {
1354         .name           = "selinuxfs",
1355         .get_sb         = sel_get_sb,
1356         .kill_sb        = kill_litter_super,
1357 };
1358
1359 struct vfsmount *selinuxfs_mount;
1360
1361 static int __init init_sel_fs(void)
1362 {
1363         int err;
1364
1365         if (!selinux_enabled)
1366                 return 0;
1367         err = register_filesystem(&sel_fs_type);
1368         if (!err) {
1369                 selinuxfs_mount = kern_mount(&sel_fs_type);
1370                 if (IS_ERR(selinuxfs_mount)) {
1371                         printk(KERN_ERR "selinuxfs:  could not mount!\n");
1372                         err = PTR_ERR(selinuxfs_mount);
1373                         selinuxfs_mount = NULL;
1374                 }
1375         }
1376         return err;
1377 }
1378
1379 __initcall(init_sel_fs);
1380
1381 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1382 void exit_sel_fs(void)
1383 {
1384         unregister_filesystem(&sel_fs_type);
1385 }
1386 #endif