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/mutex.h>
  19 #include <linux/init.h>
  20 #include <linux/string.h>
  21 #include <linux/security.h>
  22 #include <linux/major.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/percpu.h>
  25 #include <linux/audit.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/semaphore.h>
  28
  29 /* selinuxfs pseudo filesystem for exporting the security policy API.
  30    Based on the proc code and the fs/nfsd/nfsctl.c code. */
  31
  32 #include "flask.h"
  33 #include "avc.h"
  34 #include "avc_ss.h"
  35 #include "security.h"
  36 #include "objsec.h"
  37 #include "conditional.h"
  38
  39 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  40
  41 #ifdef CONFIG_SECURITY_SELINUX_ENABLE_SECMARK_DEFAULT
  42 #define SELINUX_COMPAT_NET_VALUE 0
  43 #else
  44 #define SELINUX_COMPAT_NET_VALUE 1
  45 #endif
  46
  47 int selinux_compat_net = SELINUX_COMPAT_NET_VALUE;
  48
  49 static int __init checkreqprot_setup(char *str)
  50 {
  51         selinux_checkreqprot = simple_strtoul(str,NULL,0) ? 1 : 0;
  52         return 1;
  53 }
  54 __setup("checkreqprot=", checkreqprot_setup);
  55
  56 static int __init selinux_compat_net_setup(char *str)
  57 {
  58         selinux_compat_net = simple_strtoul(str,NULL,0) ? 1 : 0;
  59         return 1;
  60 }
  61 __setup("selinux_compat_net=", selinux_compat_net_setup);
  62
  63
  64 static DEFINE_MUTEX(sel_mutex);
  65
  66 /* global data for booleans */
  67 static struct dentry *bool_dir = NULL;
  68 static int bool_num = 0;
  69 static int *bool_pending_values = NULL;
  70
  71 extern void selnl_notify_setenforce(int val);
  72
  73 /* Check whether a task is allowed to use a security operation. */
  74 static int task_has_security(struct task_struct *tsk,
  75                              u32 perms)
  76 {
  77         struct task_security_struct *tsec;
  78
  79         tsec = tsk->security;
  80         if (!tsec)
  81                 return -EACCES;
  82
  83         return avc_has_perm(tsec->sid, SECINITSID_SECURITY,
  84                             SECCLASS_SECURITY, perms, NULL);
  85 }
  86
  87 enum sel_inos {
  88         SEL_ROOT_INO = 2,
  89         SEL_LOAD,       /* load policy */
  90         SEL_ENFORCE,    /* get or set enforcing status */
  91         SEL_CONTEXT,    /* validate context */
  92         SEL_ACCESS,     /* compute access decision */
  93         SEL_CREATE,     /* compute create labeling decision */
  94         SEL_RELABEL,    /* compute relabeling decision */
  95         SEL_USER,       /* compute reachable user contexts */
  96         SEL_POLICYVERS, /* return policy version for this kernel */
  97         SEL_COMMIT_BOOLS, /* commit new boolean values */
  98         SEL_MLS,        /* return if MLS policy is enabled */
  99         SEL_DISABLE,    /* disable SELinux until next reboot */
 100         SEL_AVC,        /* AVC management directory */
 101         SEL_MEMBER,     /* compute polyinstantiation membership decision */
 102         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 103         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 104 };
 105
 106 #define TMPBUFLEN       12
 107 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 108                                 size_t count, loff_t *ppos)
 109 {
 110         char tmpbuf[TMPBUFLEN];
 111         ssize_t length;
 112
 113         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 114         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 115 }
 116
 117 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 118 static ssize_t sel_write_enforce(struct file * file, const char __user * buf,
 119                                  size_t count, loff_t *ppos)
 120
 121 {
 122         char *page;
 123         ssize_t length;
 124         int new_value;
 125
 126         if (count >= PAGE_SIZE)
 127                 return -ENOMEM;
 128         if (*ppos != 0) {
 129                 /* No partial writes. */
 130                 return -EINVAL;
 131         }
 132         page = (char*)get_zeroed_page(GFP_KERNEL);
 133         if (!page)
 134                 return -ENOMEM;
 135         length = -EFAULT;
 136         if (copy_from_user(page, buf, count))
 137                 goto out;
 138
 139         length = -EINVAL;
 140         if (sscanf(page, "%d", &new_value) != 1)
 141                 goto out;
 142
 143         if (new_value != selinux_enforcing) {
 144                 length = task_has_security(current, SECURITY__SETENFORCE);
 145                 if (length)
 146                         goto out;
 147                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 148                         "enforcing=%d old_enforcing=%d auid=%u", new_value,
 149                         selinux_enforcing,
 150                         audit_get_loginuid(current->audit_context));
 151                 selinux_enforcing = new_value;
 152                 if (selinux_enforcing)
 153                         avc_ss_reset(0);
 154                 selnl_notify_setenforce(selinux_enforcing);
 155         }
 156         length = count;
 157 out:
 158         free_page((unsigned long) page);
 159         return length;
 160 }
 161 #else
 162 #define sel_write_enforce NULL
 163 #endif
 164
 165 static struct file_operations sel_enforce_ops = {
 166         .read           = sel_read_enforce,
 167         .write          = sel_write_enforce,
 168 };
 169
 170 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
 171 static ssize_t sel_write_disable(struct file * file, const char __user * buf,
 172                                  size_t count, loff_t *ppos)
 173
 174 {
 175         char *page;
 176         ssize_t length;
 177         int new_value;
 178         extern int selinux_disable(void);
 179
 180         if (count >= PAGE_SIZE)
 181                 return -ENOMEM;
 182         if (*ppos != 0) {
 183                 /* No partial writes. */
 184                 return -EINVAL;
 185         }
 186         page = (char*)get_zeroed_page(GFP_KERNEL);
 187         if (!page)
 188                 return -ENOMEM;
 189         length = -EFAULT;
 190         if (copy_from_user(page, buf, count))
 191                 goto out;
 192
 193         length = -EINVAL;
 194         if (sscanf(page, "%d", &new_value) != 1)
 195                 goto out;
 196
 197         if (new_value) {
 198                 length = selinux_disable();
 199                 if (length < 0)
 200                         goto out;
 201                 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 202                         "selinux=0 auid=%u",
 203                         audit_get_loginuid(current->audit_context));
 204         }
 205
 206         length = count;
 207 out:
 208         free_page((unsigned long) page);
 209         return length;
 210 }
 211 #else
 212 #define sel_write_disable NULL
 213 #endif
 214
 215 static struct file_operations sel_disable_ops = {
 216         .write          = sel_write_disable,
 217 };
 218
 219 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 220                                    size_t count, loff_t *ppos)
 221 {
 222         char tmpbuf[TMPBUFLEN];
 223         ssize_t length;
 224
 225         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 226         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 227 }
 228
 229 static struct file_operations sel_policyvers_ops = {
 230         .read           = sel_read_policyvers,
 231 };
 232
 233 /* declaration for sel_write_load */
 234 static int sel_make_bools(void);
 235
 236 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 237                                 size_t count, loff_t *ppos)
 238 {
 239         char tmpbuf[TMPBUFLEN];
 240         ssize_t length;
 241
 242         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_mls_enabled);
 243         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 244 }
 245
 246 static struct file_operations sel_mls_ops = {
 247         .read           = sel_read_mls,
 248 };
 249
 250 static ssize_t sel_write_load(struct file * file, const char __user * buf,
 251                               size_t count, loff_t *ppos)
 252
 253 {
 254         int ret;
 255         ssize_t length;
 256         void *data = NULL;
 257
 258         mutex_lock(&sel_mutex);
 259
 260         length = task_has_security(current, SECURITY__LOAD_POLICY);
 261         if (length)
 262                 goto out;
 263
 264         if (*ppos != 0) {
 265                 /* No partial writes. */
 266                 length = -EINVAL;
 267                 goto out;
 268         }
 269
 270         if ((count > 64 * 1024 * 1024)
 271             || (data = vmalloc(count)) == NULL) {
 272                 length = -ENOMEM;
 273                 goto out;
 274         }
 275
 276         length = -EFAULT;
 277         if (copy_from_user(data, buf, count) != 0)
 278                 goto out;
 279
 280         length = security_load_policy(data, count);
 281         if (length)
 282                 goto out;
 283
 284         ret = sel_make_bools();
 285         if (ret)
 286                 length = ret;
 287         else
 288                 length = count;
 289         audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 290                 "policy loaded auid=%u",
 291                 audit_get_loginuid(current->audit_context));
 292 out:
 293         mutex_unlock(&sel_mutex);
 294         vfree(data);
 295         return length;
 296 }
 297
 298 static struct file_operations sel_load_ops = {
 299         .write          = sel_write_load,
 300 };
 301
 302 static ssize_t sel_write_context(struct file * file, char *buf, size_t size)
 303 {
 304         char *canon;
 305         u32 sid, len;
 306         ssize_t length;
 307
 308         length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 309         if (length)
 310                 return length;
 311
 312         length = security_context_to_sid(buf, size, &sid);
 313         if (length < 0)
 314                 return length;
 315
 316         length = security_sid_to_context(sid, &canon, &len);
 317         if (length < 0)
 318                 return length;
 319
 320         if (len > SIMPLE_TRANSACTION_LIMIT) {
 321                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 322                        "max\n", __FUNCTION__, len);
 323                 length = -ERANGE;
 324                 goto out;
 325         }
 326
 327         memcpy(buf, canon, len);
 328         length = len;
 329 out:
 330         kfree(canon);
 331         return length;
 332 }
 333
 334 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 335                                      size_t count, loff_t *ppos)
 336 {
 337         char tmpbuf[TMPBUFLEN];
 338         ssize_t length;
 339
 340         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 341         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 342 }
 343
 344 static ssize_t sel_write_checkreqprot(struct file * file, const char __user * buf,
 345                                       size_t count, loff_t *ppos)
 346 {
 347         char *page;
 348         ssize_t length;
 349         unsigned int new_value;
 350
 351         length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 352         if (length)
 353                 return length;
 354
 355         if (count >= PAGE_SIZE)
 356                 return -ENOMEM;
 357         if (*ppos != 0) {
 358                 /* No partial writes. */
 359                 return -EINVAL;
 360         }
 361         page = (char*)get_zeroed_page(GFP_KERNEL);
 362         if (!page)
 363                 return -ENOMEM;
 364         length = -EFAULT;
 365         if (copy_from_user(page, buf, count))
 366                 goto out;
 367
 368         length = -EINVAL;
 369         if (sscanf(page, "%u", &new_value) != 1)
 370                 goto out;
 371
 372         selinux_checkreqprot = new_value ? 1 : 0;
 373         length = count;
 374 out:
 375         free_page((unsigned long) page);
 376         return length;
 377 }
 378 static struct file_operations sel_checkreqprot_ops = {
 379         .read           = sel_read_checkreqprot,
 380         .write          = sel_write_checkreqprot,
 381 };
 382
 383 static ssize_t sel_read_compat_net(struct file *filp, char __user *buf,
 384                                    size_t count, loff_t *ppos)
 385 {
 386         char tmpbuf[TMPBUFLEN];
 387         ssize_t length;
 388
 389         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_compat_net);
 390         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 391 }
 392
 393 static ssize_t sel_write_compat_net(struct file * file, const char __user * buf,
 394                                     size_t count, loff_t *ppos)
 395 {
 396         char *page;
 397         ssize_t length;
 398         int new_value;
 399
 400         length = task_has_security(current, SECURITY__LOAD_POLICY);
 401         if (length)
 402                 return length;
 403
 404         if (count >= PAGE_SIZE)
 405                 return -ENOMEM;
 406         if (*ppos != 0) {
 407                 /* No partial writes. */
 408                 return -EINVAL;
 409         }
 410         page = (char*)get_zeroed_page(GFP_KERNEL);
 411         if (!page)
 412                 return -ENOMEM;
 413         length = -EFAULT;
 414         if (copy_from_user(page, buf, count))
 415                 goto out;
 416
 417         length = -EINVAL;
 418         if (sscanf(page, "%d", &new_value) != 1)
 419                 goto out;
 420
 421         selinux_compat_net = new_value ? 1 : 0;
 422         length = count;
 423 out:
 424         free_page((unsigned long) page);
 425         return length;
 426 }
 427 static struct file_operations sel_compat_net_ops = {
 428         .read           = sel_read_compat_net,
 429         .write          = sel_write_compat_net,
 430 };
 431
 432 /*
 433  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 434  */
 435 static ssize_t sel_write_access(struct file * file, char *buf, size_t size);
 436 static ssize_t sel_write_create(struct file * file, char *buf, size_t size);
 437 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size);
 438 static ssize_t sel_write_user(struct file * file, char *buf, size_t size);
 439 static ssize_t sel_write_member(struct file * file, char *buf, size_t size);
 440
 441 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 442         [SEL_ACCESS] = sel_write_access,
 443         [SEL_CREATE] = sel_write_create,
 444         [SEL_RELABEL] = sel_write_relabel,
 445         [SEL_USER] = sel_write_user,
 446         [SEL_MEMBER] = sel_write_member,
 447         [SEL_CONTEXT] = sel_write_context,
 448 };
 449
 450 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 451 {
 452         ino_t ino =  file->f_dentry->d_inode->i_ino;
 453         char *data;
 454         ssize_t rv;
 455
 456         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 457                 return -EINVAL;
 458
 459         data = simple_transaction_get(file, buf, size);
 460         if (IS_ERR(data))
 461                 return PTR_ERR(data);
 462
 463         rv =  write_op[ino](file, data, size);
 464         if (rv>0) {
 465                 simple_transaction_set(file, rv);
 466                 rv = size;
 467         }
 468         return rv;
 469 }
 470
 471 static struct file_operations transaction_ops = {
 472         .write          = selinux_transaction_write,
 473         .read           = simple_transaction_read,
 474         .release        = simple_transaction_release,
 475 };
 476
 477 /*
 478  * payload - write methods
 479  * If the method has a response, the response should be put in buf,
 480  * and the length returned.  Otherwise return 0 or and -error.
 481  */
 482
 483 static ssize_t sel_write_access(struct file * file, char *buf, size_t size)
 484 {
 485         char *scon, *tcon;
 486         u32 ssid, tsid;
 487         u16 tclass;
 488         u32 req;
 489         struct av_decision avd;
 490         ssize_t length;
 491
 492         length = task_has_security(current, SECURITY__COMPUTE_AV);
 493         if (length)
 494                 return length;
 495
 496         length = -ENOMEM;
 497         scon = kzalloc(size+1, GFP_KERNEL);
 498         if (!scon)
 499                 return length;
 500
 501         tcon = kzalloc(size+1, GFP_KERNEL);
 502         if (!tcon)
 503                 goto out;
 504
 505         length = -EINVAL;
 506         if (sscanf(buf, "%s %s %hu %x", scon, tcon, &tclass, &req) != 4)
 507                 goto out2;
 508
 509         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 510         if (length < 0)
 511                 goto out2;
 512         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 513         if (length < 0)
 514                 goto out2;
 515
 516         length = security_compute_av(ssid, tsid, tclass, req, &avd);
 517         if (length < 0)
 518                 goto out2;
 519
 520         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 521                           "%x %x %x %x %u",
 522                           avd.allowed, avd.decided,
 523                           avd.auditallow, avd.auditdeny,
 524                           avd.seqno);
 525 out2:
 526         kfree(tcon);
 527 out:
 528         kfree(scon);
 529         return length;
 530 }
 531
 532 static ssize_t sel_write_create(struct file * file, char *buf, size_t size)
 533 {
 534         char *scon, *tcon;
 535         u32 ssid, tsid, newsid;
 536         u16 tclass;
 537         ssize_t length;
 538         char *newcon;
 539         u32 len;
 540
 541         length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 542         if (length)
 543                 return length;
 544
 545         length = -ENOMEM;
 546         scon = kzalloc(size+1, GFP_KERNEL);
 547         if (!scon)
 548                 return length;
 549
 550         tcon = kzalloc(size+1, GFP_KERNEL);
 551         if (!tcon)
 552                 goto out;
 553
 554         length = -EINVAL;
 555         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 556                 goto out2;
 557
 558         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 559         if (length < 0)
 560                 goto out2;
 561         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 562         if (length < 0)
 563                 goto out2;
 564
 565         length = security_transition_sid(ssid, tsid, tclass, &newsid);
 566         if (length < 0)
 567                 goto out2;
 568
 569         length = security_sid_to_context(newsid, &newcon, &len);
 570         if (length < 0)
 571                 goto out2;
 572
 573         if (len > SIMPLE_TRANSACTION_LIMIT) {
 574                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 575                        "max\n", __FUNCTION__, len);
 576                 length = -ERANGE;
 577                 goto out3;
 578         }
 579
 580         memcpy(buf, newcon, len);
 581         length = len;
 582 out3:
 583         kfree(newcon);
 584 out2:
 585         kfree(tcon);
 586 out:
 587         kfree(scon);
 588         return length;
 589 }
 590
 591 static ssize_t sel_write_relabel(struct file * file, char *buf, size_t size)
 592 {
 593         char *scon, *tcon;
 594         u32 ssid, tsid, newsid;
 595         u16 tclass;
 596         ssize_t length;
 597         char *newcon;
 598         u32 len;
 599
 600         length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 601         if (length)
 602                 return length;
 603
 604         length = -ENOMEM;
 605         scon = kzalloc(size+1, GFP_KERNEL);
 606         if (!scon)
 607                 return length;
 608
 609         tcon = kzalloc(size+1, GFP_KERNEL);
 610         if (!tcon)
 611                 goto out;
 612
 613         length = -EINVAL;
 614         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 615                 goto out2;
 616
 617         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 618         if (length < 0)
 619                 goto out2;
 620         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 621         if (length < 0)
 622                 goto out2;
 623
 624         length = security_change_sid(ssid, tsid, tclass, &newsid);
 625         if (length < 0)
 626                 goto out2;
 627
 628         length = security_sid_to_context(newsid, &newcon, &len);
 629         if (length < 0)
 630                 goto out2;
 631
 632         if (len > SIMPLE_TRANSACTION_LIMIT) {
 633                 length = -ERANGE;
 634                 goto out3;
 635         }
 636
 637         memcpy(buf, newcon, len);
 638         length = len;
 639 out3:
 640         kfree(newcon);
 641 out2:
 642         kfree(tcon);
 643 out:
 644         kfree(scon);
 645         return length;
 646 }
 647
 648 static ssize_t sel_write_user(struct file * file, char *buf, size_t size)
 649 {
 650         char *con, *user, *ptr;
 651         u32 sid, *sids;
 652         ssize_t length;
 653         char *newcon;
 654         int i, rc;
 655         u32 len, nsids;
 656
 657         length = task_has_security(current, SECURITY__COMPUTE_USER);
 658         if (length)
 659                 return length;
 660
 661         length = -ENOMEM;
 662         con = kzalloc(size+1, GFP_KERNEL);
 663         if (!con)
 664                 return length;
 665
 666         user = kzalloc(size+1, GFP_KERNEL);
 667         if (!user)
 668                 goto out;
 669
 670         length = -EINVAL;
 671         if (sscanf(buf, "%s %s", con, user) != 2)
 672                 goto out2;
 673
 674         length = security_context_to_sid(con, strlen(con)+1, &sid);
 675         if (length < 0)
 676                 goto out2;
 677
 678         length = security_get_user_sids(sid, user, &sids, &nsids);
 679         if (length < 0)
 680                 goto out2;
 681
 682         length = sprintf(buf, "%u", nsids) + 1;
 683         ptr = buf + length;
 684         for (i = 0; i < nsids; i++) {
 685                 rc = security_sid_to_context(sids[i], &newcon, &len);
 686                 if (rc) {
 687                         length = rc;
 688                         goto out3;
 689                 }
 690                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 691                         kfree(newcon);
 692                         length = -ERANGE;
 693                         goto out3;
 694                 }
 695                 memcpy(ptr, newcon, len);
 696                 kfree(newcon);
 697                 ptr += len;
 698                 length += len;
 699         }
 700 out3:
 701         kfree(sids);
 702 out2:
 703         kfree(user);
 704 out:
 705         kfree(con);
 706         return length;
 707 }
 708
 709 static ssize_t sel_write_member(struct file * file, char *buf, size_t size)
 710 {
 711         char *scon, *tcon;
 712         u32 ssid, tsid, newsid;
 713         u16 tclass;
 714         ssize_t length;
 715         char *newcon;
 716         u32 len;
 717
 718         length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 719         if (length)
 720                 return length;
 721
 722         length = -ENOMEM;
 723         scon = kzalloc(size+1, GFP_KERNEL);
 724         if (!scon)
 725                 return length;
 726
 727         tcon = kzalloc(size+1, GFP_KERNEL);
 728         if (!tcon)
 729                 goto out;
 730
 731         length = -EINVAL;
 732         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 733                 goto out2;
 734
 735         length = security_context_to_sid(scon, strlen(scon)+1, &ssid);
 736         if (length < 0)
 737                 goto out2;
 738         length = security_context_to_sid(tcon, strlen(tcon)+1, &tsid);
 739         if (length < 0)
 740                 goto out2;
 741
 742         length = security_member_sid(ssid, tsid, tclass, &newsid);
 743         if (length < 0)
 744                 goto out2;
 745
 746         length = security_sid_to_context(newsid, &newcon, &len);
 747         if (length < 0)
 748                 goto out2;
 749
 750         if (len > SIMPLE_TRANSACTION_LIMIT) {
 751                 printk(KERN_ERR "%s:  context size (%u) exceeds payload "
 752                        "max\n", __FUNCTION__, len);
 753                 length = -ERANGE;
 754                 goto out3;
 755         }
 756
 757         memcpy(buf, newcon, len);
 758         length = len;
 759 out3:
 760         kfree(newcon);
 761 out2:
 762         kfree(tcon);
 763 out:
 764         kfree(scon);
 765         return length;
 766 }
 767
 768 static struct inode *sel_make_inode(struct super_block *sb, int mode)
 769 {
 770         struct inode *ret = new_inode(sb);
 771
 772         if (ret) {
 773                 ret->i_mode = mode;
 774                 ret->i_uid = ret->i_gid = 0;
 775                 ret->i_blksize = PAGE_CACHE_SIZE;
 776                 ret->i_blocks = 0;
 777                 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
 778         }
 779         return ret;
 780 }
 781
 782 #define BOOL_INO_OFFSET 30
 783
 784 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 785                              size_t count, loff_t *ppos)
 786 {
 787         char *page = NULL;
 788         ssize_t length;
 789         ssize_t ret;
 790         int cur_enforcing;
 791         struct inode *inode;
 792
 793         mutex_lock(&sel_mutex);
 794
 795         ret = -EFAULT;
 796
 797         /* check to see if this file has been deleted */
 798         if (!filep->f_op)
 799                 goto out;
 800
 801         if (count > PAGE_SIZE) {
 802                 ret = -EINVAL;
 803                 goto out;
 804         }
 805         if (!(page = (char*)get_zeroed_page(GFP_KERNEL))) {
 806                 ret = -ENOMEM;
 807                 goto out;
 808         }
 809
 810         inode = filep->f_dentry->d_inode;
 811         cur_enforcing = security_get_bool_value(inode->i_ino - BOOL_INO_OFFSET);
 812         if (cur_enforcing < 0) {
 813                 ret = cur_enforcing;
 814                 goto out;
 815         }
 816
 817         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
 818                           bool_pending_values[inode->i_ino - BOOL_INO_OFFSET]);
 819         ret = simple_read_from_buffer(buf, count, ppos, page, length);
 820 out:
 821         mutex_unlock(&sel_mutex);
 822         if (page)
 823                 free_page((unsigned long)page);
 824         return ret;
 825 }
 826
 827 static ssize_t sel_write_bool(struct file *filep, 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         struct inode *inode;
 834
 835         mutex_lock(&sel_mutex);
 836
 837         length = task_has_security(current, SECURITY__SETBOOL);
 838         if (length)
 839                 goto out;
 840
 841         /* check to see if this file has been deleted */
 842         if (!filep->f_op)
 843                 goto out;
 844
 845         if (count >= PAGE_SIZE) {
 846                 length = -ENOMEM;
 847                 goto out;
 848         }
 849         if (*ppos != 0) {
 850                 /* No partial writes. */
 851                 goto out;
 852         }
 853         page = (char*)get_zeroed_page(GFP_KERNEL);
 854         if (!page) {
 855                 length = -ENOMEM;
 856                 goto out;
 857         }
 858
 859         if (copy_from_user(page, buf, count))
 860                 goto out;
 861
 862         length = -EINVAL;
 863         if (sscanf(page, "%d", &new_value) != 1)
 864                 goto out;
 865
 866         if (new_value)
 867                 new_value = 1;
 868
 869         inode = filep->f_dentry->d_inode;
 870         bool_pending_values[inode->i_ino - BOOL_INO_OFFSET] = new_value;
 871         length = count;
 872
 873 out:
 874         mutex_unlock(&sel_mutex);
 875         if (page)
 876                 free_page((unsigned long) page);
 877         return length;
 878 }
 879
 880 static struct file_operations sel_bool_ops = {
 881         .read           = sel_read_bool,
 882         .write          = sel_write_bool,
 883 };
 884
 885 static ssize_t sel_commit_bools_write(struct file *filep,
 886                                       const char __user *buf,
 887                                       size_t count, loff_t *ppos)
 888 {
 889         char *page = NULL;
 890         ssize_t length = -EFAULT;
 891         int new_value;
 892
 893         mutex_lock(&sel_mutex);
 894
 895         length = task_has_security(current, SECURITY__SETBOOL);
 896         if (length)
 897                 goto out;
 898
 899         /* check to see if this file has been deleted */
 900         if (!filep->f_op)
 901                 goto out;
 902
 903         if (count >= PAGE_SIZE) {
 904                 length = -ENOMEM;
 905                 goto out;
 906         }
 907         if (*ppos != 0) {
 908                 /* No partial writes. */
 909                 goto out;
 910         }
 911         page = (char*)get_zeroed_page(GFP_KERNEL);
 912         if (!page) {
 913                 length = -ENOMEM;
 914                 goto out;
 915         }
 916
 917         if (copy_from_user(page, buf, count))
 918                 goto out;
 919
 920         length = -EINVAL;
 921         if (sscanf(page, "%d", &new_value) != 1)
 922                 goto out;
 923
 924         if (new_value && bool_pending_values) {
 925                 security_set_bools(bool_num, bool_pending_values);
 926         }
 927
 928         length = count;
 929
 930 out:
 931         mutex_unlock(&sel_mutex);
 932         if (page)
 933                 free_page((unsigned long) page);
 934         return length;
 935 }
 936
 937 static struct file_operations sel_commit_bools_ops = {
 938         .write          = sel_commit_bools_write,
 939 };
 940
 941 /* delete booleans - partial revoke() from
 942  * fs/proc/generic.c proc_kill_inodes */
 943 static void sel_remove_bools(struct dentry *de)
 944 {
 945         struct list_head *p, *node;
 946         struct super_block *sb = de->d_sb;
 947
 948         spin_lock(&dcache_lock);
 949         node = de->d_subdirs.next;
 950         while (node != &de->d_subdirs) {
 951                 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
 952                 list_del_init(node);
 953
 954                 if (d->d_inode) {
 955                         d = dget_locked(d);
 956                         spin_unlock(&dcache_lock);
 957                         d_delete(d);
 958                         simple_unlink(de->d_inode, d);
 959                         dput(d);
 960                         spin_lock(&dcache_lock);
 961                 }
 962                 node = de->d_subdirs.next;
 963         }
 964
 965         spin_unlock(&dcache_lock);
 966
 967         file_list_lock();
 968         list_for_each(p, &sb->s_files) {
 969                 struct file * filp = list_entry(p, struct file, f_u.fu_list);
 970                 struct dentry * dentry = filp->f_dentry;
 971
 972                 if (dentry->d_parent != de) {
 973                         continue;
 974                 }
 975                 filp->f_op = NULL;
 976         }
 977         file_list_unlock();
 978 }
 979
 980 #define BOOL_DIR_NAME "booleans"
 981
 982 static int sel_make_bools(void)
 983 {
 984         int i, ret = 0;
 985         ssize_t len;
 986         struct dentry *dentry = NULL;
 987         struct dentry *dir = bool_dir;
 988         struct inode *inode = NULL;
 989         struct inode_security_struct *isec;
 990         char **names = NULL, *page;
 991         int num;
 992         int *values = NULL;
 993         u32 sid;
 994
 995         /* remove any existing files */
 996         kfree(bool_pending_values);
 997         bool_pending_values = NULL;
 998
 999         sel_remove_bools(dir);
1000
1001         if (!(page = (char*)get_zeroed_page(GFP_KERNEL)))
1002                 return -ENOMEM;
1003
1004         ret = security_get_bools(&num, &names, &values);
1005         if (ret != 0)
1006                 goto out;
1007
1008         for (i = 0; i < num; i++) {
1009                 dentry = d_alloc_name(dir, names[i]);
1010                 if (!dentry) {
1011                         ret = -ENOMEM;
1012                         goto err;
1013                 }
1014                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1015                 if (!inode) {
1016                         ret = -ENOMEM;
1017                         goto err;
1018                 }
1019
1020                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1021                 if (len < 0) {
1022                         ret = -EINVAL;
1023                         goto err;
1024                 } else if (len >= PAGE_SIZE) {
1025                         ret = -ENAMETOOLONG;
1026                         goto err;
1027                 }
1028                 isec = (struct inode_security_struct*)inode->i_security;
1029                 if ((ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid)))
1030                         goto err;
1031                 isec->sid = sid;
1032                 isec->initialized = 1;
1033                 inode->i_fop = &sel_bool_ops;
1034                 inode->i_ino = i + BOOL_INO_OFFSET;
1035                 d_add(dentry, inode);
1036         }
1037         bool_num = num;
1038         bool_pending_values = values;
1039 out:
1040         free_page((unsigned long)page);
1041         if (names) {
1042                 for (i = 0; i < num; i++)
1043                         kfree(names[i]);
1044                 kfree(names);
1045         }
1046         return ret;
1047 err:
1048         kfree(values);
1049         sel_remove_bools(dir);
1050         ret = -ENOMEM;
1051         goto out;
1052 }
1053
1054 #define NULL_FILE_NAME "null"
1055
1056 struct dentry *selinux_null = NULL;
1057
1058 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1059                                             size_t count, loff_t *ppos)
1060 {
1061         char tmpbuf[TMPBUFLEN];
1062         ssize_t length;
1063
1064         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1065         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1066 }
1067
1068 static ssize_t sel_write_avc_cache_threshold(struct file * file,
1069                                              const char __user * buf,
1070                                              size_t count, loff_t *ppos)
1071
1072 {
1073         char *page;
1074         ssize_t ret;
1075         int new_value;
1076
1077         if (count >= PAGE_SIZE) {
1078                 ret = -ENOMEM;
1079                 goto out;
1080         }
1081
1082         if (*ppos != 0) {
1083                 /* No partial writes. */
1084                 ret = -EINVAL;
1085                 goto out;
1086         }
1087
1088         page = (char*)get_zeroed_page(GFP_KERNEL);
1089         if (!page) {
1090                 ret = -ENOMEM;
1091                 goto out;
1092         }
1093
1094         if (copy_from_user(page, buf, count)) {
1095                 ret = -EFAULT;
1096                 goto out_free;
1097         }
1098
1099         if (sscanf(page, "%u", &new_value) != 1) {
1100                 ret = -EINVAL;
1101                 goto out;
1102         }
1103
1104         if (new_value != avc_cache_threshold) {
1105                 ret = task_has_security(current, SECURITY__SETSECPARAM);
1106                 if (ret)
1107                         goto out_free;
1108                 avc_cache_threshold = new_value;
1109         }
1110         ret = count;
1111 out_free:
1112         free_page((unsigned long)page);
1113 out:
1114         return ret;
1115 }
1116
1117 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1118                                        size_t count, loff_t *ppos)
1119 {
1120         char *page;
1121         ssize_t ret = 0;
1122
1123         page = (char *)__get_free_page(GFP_KERNEL);
1124         if (!page) {
1125                 ret = -ENOMEM;
1126                 goto out;
1127         }
1128         ret = avc_get_hash_stats(page);
1129         if (ret >= 0)
1130                 ret = simple_read_from_buffer(buf, count, ppos, page, ret);
1131         free_page((unsigned long)page);
1132 out:
1133         return ret;
1134 }
1135
1136 static struct file_operations sel_avc_cache_threshold_ops = {
1137         .read           = sel_read_avc_cache_threshold,
1138         .write          = sel_write_avc_cache_threshold,
1139 };
1140
1141 static struct file_operations sel_avc_hash_stats_ops = {
1142         .read           = sel_read_avc_hash_stats,
1143 };
1144
1145 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1146 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1147 {
1148         int cpu;
1149
1150         for (cpu = *idx; cpu < NR_CPUS; ++cpu) {
1151                 if (!cpu_possible(cpu))
1152                         continue;
1153                 *idx = cpu + 1;
1154                 return &per_cpu(avc_cache_stats, cpu);
1155         }
1156         return NULL;
1157 }
1158
1159 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1160 {
1161         loff_t n = *pos - 1;
1162
1163         if (*pos == 0)
1164                 return SEQ_START_TOKEN;
1165
1166         return sel_avc_get_stat_idx(&n);
1167 }
1168
1169 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1170 {
1171         return sel_avc_get_stat_idx(pos);
1172 }
1173
1174 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1175 {
1176         struct avc_cache_stats *st = v;
1177
1178         if (v == SEQ_START_TOKEN)
1179                 seq_printf(seq, "lookups hits misses allocations reclaims "
1180                            "frees\n");
1181         else
1182                 seq_printf(seq, "%u %u %u %u %u %u\n", st->lookups,
1183                            st->hits, st->misses, st->allocations,
1184                            st->reclaims, st->frees);
1185         return 0;
1186 }
1187
1188 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1189 { }
1190
1191 static struct seq_operations sel_avc_cache_stats_seq_ops = {
1192         .start          = sel_avc_stats_seq_start,
1193         .next           = sel_avc_stats_seq_next,
1194         .show           = sel_avc_stats_seq_show,
1195         .stop           = sel_avc_stats_seq_stop,
1196 };
1197
1198 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1199 {
1200         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1201 }
1202
1203 static struct file_operations sel_avc_cache_stats_ops = {
1204         .open           = sel_open_avc_cache_stats,
1205         .read           = seq_read,
1206         .llseek         = seq_lseek,
1207         .release        = seq_release,
1208 };
1209 #endif
1210
1211 static int sel_make_avc_files(struct dentry *dir)
1212 {
1213         int i, ret = 0;
1214         static struct tree_descr files[] = {
1215                 { "cache_threshold",
1216                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1217                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1218 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1219                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1220 #endif
1221         };
1222
1223         for (i = 0; i < ARRAY_SIZE(files); i++) {
1224                 struct inode *inode;
1225                 struct dentry *dentry;
1226
1227                 dentry = d_alloc_name(dir, files[i].name);
1228                 if (!dentry) {
1229                         ret = -ENOMEM;
1230                         goto out;
1231                 }
1232
1233                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1234                 if (!inode) {
1235                         ret = -ENOMEM;
1236                         goto out;
1237                 }
1238                 inode->i_fop = files[i].ops;
1239                 d_add(dentry, inode);
1240         }
1241 out:
1242         return ret;
1243 }
1244
1245 static int sel_make_dir(struct inode *dir, struct dentry *dentry)
1246 {
1247         int ret = 0;
1248         struct inode *inode;
1249
1250         inode = sel_make_inode(dir->i_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1251         if (!inode) {
1252                 ret = -ENOMEM;
1253                 goto out;
1254         }
1255         inode->i_op = &simple_dir_inode_operations;
1256         inode->i_fop = &simple_dir_operations;
1257         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1258         inode->i_nlink++;
1259         d_add(dentry, inode);
1260         /* bump link count on parent directory, too */
1261         dir->i_nlink++;
1262 out:
1263         return ret;
1264 }
1265
1266 static int sel_fill_super(struct super_block * sb, void * data, int silent)
1267 {
1268         int ret;
1269         struct dentry *dentry;
1270         struct inode *inode, *root_inode;
1271         struct inode_security_struct *isec;
1272
1273         static struct tree_descr selinux_files[] = {
1274                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1275                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1276                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1277                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1278                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1279                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1280                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1281                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1282                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1283                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1284                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1285                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1286                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1287                 [SEL_COMPAT_NET] = {"compat_net", &sel_compat_net_ops, S_IRUGO|S_IWUSR},
1288                 /* last one */ {""}
1289         };
1290         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1291         if (ret)
1292                 goto err;
1293
1294         root_inode = sb->s_root->d_inode;
1295
1296         dentry = d_alloc_name(sb->s_root, BOOL_DIR_NAME);
1297         if (!dentry) {
1298                 ret = -ENOMEM;
1299                 goto err;
1300         }
1301
1302         ret = sel_make_dir(root_inode, dentry);
1303         if (ret)
1304                 goto err;
1305
1306         bool_dir = dentry;
1307
1308         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1309         if (!dentry) {
1310                 ret = -ENOMEM;
1311                 goto err;
1312         }
1313
1314         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1315         if (!inode) {
1316                 ret = -ENOMEM;
1317                 goto err;
1318         }
1319         isec = (struct inode_security_struct*)inode->i_security;
1320         isec->sid = SECINITSID_DEVNULL;
1321         isec->sclass = SECCLASS_CHR_FILE;
1322         isec->initialized = 1;
1323
1324         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1325         d_add(dentry, inode);
1326         selinux_null = dentry;
1327
1328         dentry = d_alloc_name(sb->s_root, "avc");
1329         if (!dentry) {
1330                 ret = -ENOMEM;
1331                 goto err;
1332         }
1333
1334         ret = sel_make_dir(root_inode, dentry);
1335         if (ret)
1336                 goto err;
1337
1338         ret = sel_make_avc_files(dentry);
1339         if (ret)
1340                 goto err;
1341 out:
1342         return ret;
1343 err:
1344         printk(KERN_ERR "%s:  failed while creating inodes\n", __FUNCTION__);
1345         goto out;
1346 }
1347
1348 static struct super_block *sel_get_sb(struct file_system_type *fs_type,
1349                                       int flags, const char *dev_name, void *data)
1350 {
1351         return get_sb_single(fs_type, flags, data, sel_fill_super);
1352 }
1353
1354 static struct file_system_type sel_fs_type = {
1355         .name           = "selinuxfs",
1356         .get_sb         = sel_get_sb,
1357         .kill_sb        = kill_litter_super,
1358 };
1359
1360 struct vfsmount *selinuxfs_mount;
1361
1362 static int __init init_sel_fs(void)
1363 {
1364         int err;
1365
1366         if (!selinux_enabled)
1367                 return 0;
1368         err = register_filesystem(&sel_fs_type);
1369         if (!err) {
1370                 selinuxfs_mount = kern_mount(&sel_fs_type);
1371                 if (IS_ERR(selinuxfs_mount)) {
1372                         printk(KERN_ERR "selinuxfs:  could not mount!\n");
1373                         err = PTR_ERR(selinuxfs_mount);
1374                         selinuxfs_mount = NULL;
1375                 }
1376         }
1377         return err;
1378 }
1379
1380 __initcall(init_sel_fs);
1381
1382 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1383 void exit_sel_fs(void)
1384 {
1385         unregister_filesystem(&sel_fs_type);
1386 }
1387 #endif