linux/security/selinux/selinuxfs.c
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   1/* Updated: Karl MacMillan <kmacmillan@tresys.com>
   2 *
   3 *      Added conditional policy language extensions
   4 *
   5 *  Updated: Hewlett-Packard <paul@paul-moore.com>
   6 *
   7 *      Added support for the policy capability bitmap
   8 *
   9 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  10 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
  11 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
  12 *      This program is free software; you can redistribute it and/or modify
  13 *      it under the terms of the GNU General Public License as published by
  14 *      the Free Software Foundation, version 2.
  15 */
  16
  17#include <linux/kernel.h>
  18#include <linux/pagemap.h>
  19#include <linux/slab.h>
  20#include <linux/vmalloc.h>
  21#include <linux/fs.h>
  22#include <linux/mutex.h>
  23#include <linux/init.h>
  24#include <linux/string.h>
  25#include <linux/security.h>
  26#include <linux/major.h>
  27#include <linux/seq_file.h>
  28#include <linux/percpu.h>
  29#include <linux/audit.h>
  30#include <linux/uaccess.h>
  31#include <linux/kobject.h>
  32#include <linux/ctype.h>
  33
  34/* selinuxfs pseudo filesystem for exporting the security policy API.
  35   Based on the proc code and the fs/nfsd/nfsctl.c code. */
  36
  37#include "flask.h"
  38#include "avc.h"
  39#include "avc_ss.h"
  40#include "security.h"
  41#include "objsec.h"
  42#include "conditional.h"
  43
  44/* Policy capability filenames */
  45static char *policycap_names[] = {
  46        "network_peer_controls",
  47        "open_perms"
  48};
  49
  50unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  51
  52static int __init checkreqprot_setup(char *str)
  53{
  54        unsigned long checkreqprot;
  55        if (!strict_strtoul(str, 0, &checkreqprot))
  56                selinux_checkreqprot = checkreqprot ? 1 : 0;
  57        return 1;
  58}
  59__setup("checkreqprot=", checkreqprot_setup);
  60
  61static DEFINE_MUTEX(sel_mutex);
  62
  63/* global data for booleans */
  64static struct dentry *bool_dir;
  65static int bool_num;
  66static char **bool_pending_names;
  67static int *bool_pending_values;
  68
  69/* global data for classes */
  70static struct dentry *class_dir;
  71static unsigned long last_class_ino;
  72
  73static char policy_opened;
  74
  75/* global data for policy capabilities */
  76static struct dentry *policycap_dir;
  77
  78/* Check whether a task is allowed to use a security operation. */
  79static int task_has_security(struct task_struct *tsk,
  80                             u32 perms)
  81{
  82        const struct task_security_struct *tsec;
  83        u32 sid = 0;
  84
  85        rcu_read_lock();
  86        tsec = __task_cred(tsk)->security;
  87        if (tsec)
  88                sid = tsec->sid;
  89        rcu_read_unlock();
  90        if (!tsec)
  91                return -EACCES;
  92
  93        return avc_has_perm(sid, SECINITSID_SECURITY,
  94                            SECCLASS_SECURITY, perms, NULL);
  95}
  96
  97enum sel_inos {
  98        SEL_ROOT_INO = 2,
  99        SEL_LOAD,       /* load policy */
 100        SEL_ENFORCE,    /* get or set enforcing status */
 101        SEL_CONTEXT,    /* validate context */
 102        SEL_ACCESS,     /* compute access decision */
 103        SEL_CREATE,     /* compute create labeling decision */
 104        SEL_RELABEL,    /* compute relabeling decision */
 105        SEL_USER,       /* compute reachable user contexts */
 106        SEL_POLICYVERS, /* return policy version for this kernel */
 107        SEL_COMMIT_BOOLS, /* commit new boolean values */
 108        SEL_MLS,        /* return if MLS policy is enabled */
 109        SEL_DISABLE,    /* disable SELinux until next reboot */
 110        SEL_MEMBER,     /* compute polyinstantiation membership decision */
 111        SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 112        SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 113        SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
 114        SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 115        SEL_STATUS,     /* export current status using mmap() */
 116        SEL_POLICY,     /* allow userspace to read the in kernel policy */
 117        SEL_INO_NEXT,   /* The next inode number to use */
 118};
 119
 120static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 121
 122#define SEL_INITCON_INO_OFFSET          0x01000000
 123#define SEL_BOOL_INO_OFFSET             0x02000000
 124#define SEL_CLASS_INO_OFFSET            0x04000000
 125#define SEL_POLICYCAP_INO_OFFSET        0x08000000
 126#define SEL_INO_MASK                    0x00ffffff
 127
 128#define TMPBUFLEN       12
 129static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 130                                size_t count, loff_t *ppos)
 131{
 132        char tmpbuf[TMPBUFLEN];
 133        ssize_t length;
 134
 135        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 136        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 137}
 138
 139#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 140static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 141                                 size_t count, loff_t *ppos)
 142
 143{
 144        char *page = NULL;
 145        ssize_t length;
 146        int new_value;
 147
 148        length = -ENOMEM;
 149        if (count >= PAGE_SIZE)
 150                goto out;
 151
 152        /* No partial writes. */
 153        length = EINVAL;
 154        if (*ppos != 0)
 155                goto out;
 156
 157        length = -ENOMEM;
 158        page = (char *)get_zeroed_page(GFP_KERNEL);
 159        if (!page)
 160                goto out;
 161
 162        length = -EFAULT;
 163        if (copy_from_user(page, buf, count))
 164                goto out;
 165
 166        length = -EINVAL;
 167        if (sscanf(page, "%d", &new_value) != 1)
 168                goto out;
 169
 170        if (new_value != selinux_enforcing) {
 171                length = task_has_security(current, SECURITY__SETENFORCE);
 172                if (length)
 173                        goto out;
 174                audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 175                        "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 176                        new_value, selinux_enforcing,
 177                        from_kuid(&init_user_ns, audit_get_loginuid(current)),
 178                        audit_get_sessionid(current));
 179                selinux_enforcing = new_value;
 180                if (selinux_enforcing)
 181                        avc_ss_reset(0);
 182                selnl_notify_setenforce(selinux_enforcing);
 183                selinux_status_update_setenforce(selinux_enforcing);
 184        }
 185        length = count;
 186out:
 187        free_page((unsigned long) page);
 188        return length;
 189}
 190#else
 191#define sel_write_enforce NULL
 192#endif
 193
 194static const struct file_operations sel_enforce_ops = {
 195        .read           = sel_read_enforce,
 196        .write          = sel_write_enforce,
 197        .llseek         = generic_file_llseek,
 198};
 199
 200static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 201                                        size_t count, loff_t *ppos)
 202{
 203        char tmpbuf[TMPBUFLEN];
 204        ssize_t length;
 205        ino_t ino = file_inode(filp)->i_ino;
 206        int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 207                security_get_reject_unknown() : !security_get_allow_unknown();
 208
 209        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 210        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 211}
 212
 213static const struct file_operations sel_handle_unknown_ops = {
 214        .read           = sel_read_handle_unknown,
 215        .llseek         = generic_file_llseek,
 216};
 217
 218static int sel_open_handle_status(struct inode *inode, struct file *filp)
 219{
 220        struct page    *status = selinux_kernel_status_page();
 221
 222        if (!status)
 223                return -ENOMEM;
 224
 225        filp->private_data = status;
 226
 227        return 0;
 228}
 229
 230static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 231                                      size_t count, loff_t *ppos)
 232{
 233        struct page    *status = filp->private_data;
 234
 235        BUG_ON(!status);
 236
 237        return simple_read_from_buffer(buf, count, ppos,
 238                                       page_address(status),
 239                                       sizeof(struct selinux_kernel_status));
 240}
 241
 242static int sel_mmap_handle_status(struct file *filp,
 243                                  struct vm_area_struct *vma)
 244{
 245        struct page    *status = filp->private_data;
 246        unsigned long   size = vma->vm_end - vma->vm_start;
 247
 248        BUG_ON(!status);
 249
 250        /* only allows one page from the head */
 251        if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 252                return -EIO;
 253        /* disallow writable mapping */
 254        if (vma->vm_flags & VM_WRITE)
 255                return -EPERM;
 256        /* disallow mprotect() turns it into writable */
 257        vma->vm_flags &= ~VM_MAYWRITE;
 258
 259        return remap_pfn_range(vma, vma->vm_start,
 260                               page_to_pfn(status),
 261                               size, vma->vm_page_prot);
 262}
 263
 264static const struct file_operations sel_handle_status_ops = {
 265        .open           = sel_open_handle_status,
 266        .read           = sel_read_handle_status,
 267        .mmap           = sel_mmap_handle_status,
 268        .llseek         = generic_file_llseek,
 269};
 270
 271#ifdef CONFIG_SECURITY_SELINUX_DISABLE
 272static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 273                                 size_t count, loff_t *ppos)
 274
 275{
 276        char *page = NULL;
 277        ssize_t length;
 278        int new_value;
 279
 280        length = -ENOMEM;
 281        if (count >= PAGE_SIZE)
 282                goto out;
 283
 284        /* No partial writes. */
 285        length = -EINVAL;
 286        if (*ppos != 0)
 287                goto out;
 288
 289        length = -ENOMEM;
 290        page = (char *)get_zeroed_page(GFP_KERNEL);
 291        if (!page)
 292                goto out;
 293
 294        length = -EFAULT;
 295        if (copy_from_user(page, buf, count))
 296                goto out;
 297
 298        length = -EINVAL;
 299        if (sscanf(page, "%d", &new_value) != 1)
 300                goto out;
 301
 302        if (new_value) {
 303                length = selinux_disable();
 304                if (length)
 305                        goto out;
 306                audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 307                        "selinux=0 auid=%u ses=%u",
 308                        from_kuid(&init_user_ns, audit_get_loginuid(current)),
 309                        audit_get_sessionid(current));
 310        }
 311
 312        length = count;
 313out:
 314        free_page((unsigned long) page);
 315        return length;
 316}
 317#else
 318#define sel_write_disable NULL
 319#endif
 320
 321static const struct file_operations sel_disable_ops = {
 322        .write          = sel_write_disable,
 323        .llseek         = generic_file_llseek,
 324};
 325
 326static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 327                                   size_t count, loff_t *ppos)
 328{
 329        char tmpbuf[TMPBUFLEN];
 330        ssize_t length;
 331
 332        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 333        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 334}
 335
 336static const struct file_operations sel_policyvers_ops = {
 337        .read           = sel_read_policyvers,
 338        .llseek         = generic_file_llseek,
 339};
 340
 341/* declaration for sel_write_load */
 342static int sel_make_bools(void);
 343static int sel_make_classes(void);
 344static int sel_make_policycap(void);
 345
 346/* declaration for sel_make_class_dirs */
 347static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 348                        unsigned long *ino);
 349
 350static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 351                                size_t count, loff_t *ppos)
 352{
 353        char tmpbuf[TMPBUFLEN];
 354        ssize_t length;
 355
 356        length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 357                           security_mls_enabled());
 358        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 359}
 360
 361static const struct file_operations sel_mls_ops = {
 362        .read           = sel_read_mls,
 363        .llseek         = generic_file_llseek,
 364};
 365
 366struct policy_load_memory {
 367        size_t len;
 368        void *data;
 369};
 370
 371static int sel_open_policy(struct inode *inode, struct file *filp)
 372{
 373        struct policy_load_memory *plm = NULL;
 374        int rc;
 375
 376        BUG_ON(filp->private_data);
 377
 378        mutex_lock(&sel_mutex);
 379
 380        rc = task_has_security(current, SECURITY__READ_POLICY);
 381        if (rc)
 382                goto err;
 383
 384        rc = -EBUSY;
 385        if (policy_opened)
 386                goto err;
 387
 388        rc = -ENOMEM;
 389        plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 390        if (!plm)
 391                goto err;
 392
 393        if (i_size_read(inode) != security_policydb_len()) {
 394                mutex_lock(&inode->i_mutex);
 395                i_size_write(inode, security_policydb_len());
 396                mutex_unlock(&inode->i_mutex);
 397        }
 398
 399        rc = security_read_policy(&plm->data, &plm->len);
 400        if (rc)
 401                goto err;
 402
 403        policy_opened = 1;
 404
 405        filp->private_data = plm;
 406
 407        mutex_unlock(&sel_mutex);
 408
 409        return 0;
 410err:
 411        mutex_unlock(&sel_mutex);
 412
 413        if (plm)
 414                vfree(plm->data);
 415        kfree(plm);
 416        return rc;
 417}
 418
 419static int sel_release_policy(struct inode *inode, struct file *filp)
 420{
 421        struct policy_load_memory *plm = filp->private_data;
 422
 423        BUG_ON(!plm);
 424
 425        policy_opened = 0;
 426
 427        vfree(plm->data);
 428        kfree(plm);
 429
 430        return 0;
 431}
 432
 433static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 434                               size_t count, loff_t *ppos)
 435{
 436        struct policy_load_memory *plm = filp->private_data;
 437        int ret;
 438
 439        mutex_lock(&sel_mutex);
 440
 441        ret = task_has_security(current, SECURITY__READ_POLICY);
 442        if (ret)
 443                goto out;
 444
 445        ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 446out:
 447        mutex_unlock(&sel_mutex);
 448        return ret;
 449}
 450
 451static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 452                                 struct vm_fault *vmf)
 453{
 454        struct policy_load_memory *plm = vma->vm_file->private_data;
 455        unsigned long offset;
 456        struct page *page;
 457
 458        if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 459                return VM_FAULT_SIGBUS;
 460
 461        offset = vmf->pgoff << PAGE_SHIFT;
 462        if (offset >= roundup(plm->len, PAGE_SIZE))
 463                return VM_FAULT_SIGBUS;
 464
 465        page = vmalloc_to_page(plm->data + offset);
 466        get_page(page);
 467
 468        vmf->page = page;
 469
 470        return 0;
 471}
 472
 473static struct vm_operations_struct sel_mmap_policy_ops = {
 474        .fault = sel_mmap_policy_fault,
 475        .page_mkwrite = sel_mmap_policy_fault,
 476};
 477
 478static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 479{
 480        if (vma->vm_flags & VM_SHARED) {
 481                /* do not allow mprotect to make mapping writable */
 482                vma->vm_flags &= ~VM_MAYWRITE;
 483
 484                if (vma->vm_flags & VM_WRITE)
 485                        return -EACCES;
 486        }
 487
 488        vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 489        vma->vm_ops = &sel_mmap_policy_ops;
 490
 491        return 0;
 492}
 493
 494static const struct file_operations sel_policy_ops = {
 495        .open           = sel_open_policy,
 496        .read           = sel_read_policy,
 497        .mmap           = sel_mmap_policy,
 498        .release        = sel_release_policy,
 499        .llseek         = generic_file_llseek,
 500};
 501
 502static ssize_t sel_write_load(struct file *file, const char __user *buf,
 503                              size_t count, loff_t *ppos)
 504
 505{
 506        ssize_t length;
 507        void *data = NULL;
 508
 509        mutex_lock(&sel_mutex);
 510
 511        length = task_has_security(current, SECURITY__LOAD_POLICY);
 512        if (length)
 513                goto out;
 514
 515        /* No partial writes. */
 516        length = -EINVAL;
 517        if (*ppos != 0)
 518                goto out;
 519
 520        length = -EFBIG;
 521        if (count > 64 * 1024 * 1024)
 522                goto out;
 523
 524        length = -ENOMEM;
 525        data = vmalloc(count);
 526        if (!data)
 527                goto out;
 528
 529        length = -EFAULT;
 530        if (copy_from_user(data, buf, count) != 0)
 531                goto out;
 532
 533        length = security_load_policy(data, count);
 534        if (length)
 535                goto out;
 536
 537        length = sel_make_bools();
 538        if (length)
 539                goto out1;
 540
 541        length = sel_make_classes();
 542        if (length)
 543                goto out1;
 544
 545        length = sel_make_policycap();
 546        if (length)
 547                goto out1;
 548
 549        length = count;
 550
 551out1:
 552        audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 553                "policy loaded auid=%u ses=%u",
 554                from_kuid(&init_user_ns, audit_get_loginuid(current)),
 555                audit_get_sessionid(current));
 556out:
 557        mutex_unlock(&sel_mutex);
 558        vfree(data);
 559        return length;
 560}
 561
 562static const struct file_operations sel_load_ops = {
 563        .write          = sel_write_load,
 564        .llseek         = generic_file_llseek,
 565};
 566
 567static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 568{
 569        char *canon = NULL;
 570        u32 sid, len;
 571        ssize_t length;
 572
 573        length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 574        if (length)
 575                goto out;
 576
 577        length = security_context_to_sid(buf, size, &sid);
 578        if (length)
 579                goto out;
 580
 581        length = security_sid_to_context(sid, &canon, &len);
 582        if (length)
 583                goto out;
 584
 585        length = -ERANGE;
 586        if (len > SIMPLE_TRANSACTION_LIMIT) {
 587                printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 588                        "payload max\n", __func__, len);
 589                goto out;
 590        }
 591
 592        memcpy(buf, canon, len);
 593        length = len;
 594out:
 595        kfree(canon);
 596        return length;
 597}
 598
 599static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 600                                     size_t count, loff_t *ppos)
 601{
 602        char tmpbuf[TMPBUFLEN];
 603        ssize_t length;
 604
 605        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 606        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 607}
 608
 609static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 610                                      size_t count, loff_t *ppos)
 611{
 612        char *page = NULL;
 613        ssize_t length;
 614        unsigned int new_value;
 615
 616        length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 617        if (length)
 618                goto out;
 619
 620        length = -ENOMEM;
 621        if (count >= PAGE_SIZE)
 622                goto out;
 623
 624        /* No partial writes. */
 625        length = -EINVAL;
 626        if (*ppos != 0)
 627                goto out;
 628
 629        length = -ENOMEM;
 630        page = (char *)get_zeroed_page(GFP_KERNEL);
 631        if (!page)
 632                goto out;
 633
 634        length = -EFAULT;
 635        if (copy_from_user(page, buf, count))
 636                goto out;
 637
 638        length = -EINVAL;
 639        if (sscanf(page, "%u", &new_value) != 1)
 640                goto out;
 641
 642        selinux_checkreqprot = new_value ? 1 : 0;
 643        length = count;
 644out:
 645        free_page((unsigned long) page);
 646        return length;
 647}
 648static const struct file_operations sel_checkreqprot_ops = {
 649        .read           = sel_read_checkreqprot,
 650        .write          = sel_write_checkreqprot,
 651        .llseek         = generic_file_llseek,
 652};
 653
 654/*
 655 * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 656 */
 657static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 658static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 659static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 660static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 661static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 662
 663static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 664        [SEL_ACCESS] = sel_write_access,
 665        [SEL_CREATE] = sel_write_create,
 666        [SEL_RELABEL] = sel_write_relabel,
 667        [SEL_USER] = sel_write_user,
 668        [SEL_MEMBER] = sel_write_member,
 669        [SEL_CONTEXT] = sel_write_context,
 670};
 671
 672static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 673{
 674        ino_t ino = file_inode(file)->i_ino;
 675        char *data;
 676        ssize_t rv;
 677
 678        if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 679                return -EINVAL;
 680
 681        data = simple_transaction_get(file, buf, size);
 682        if (IS_ERR(data))
 683                return PTR_ERR(data);
 684
 685        rv = write_op[ino](file, data, size);
 686        if (rv > 0) {
 687                simple_transaction_set(file, rv);
 688                rv = size;
 689        }
 690        return rv;
 691}
 692
 693static const struct file_operations transaction_ops = {
 694        .write          = selinux_transaction_write,
 695        .read           = simple_transaction_read,
 696        .release        = simple_transaction_release,
 697        .llseek         = generic_file_llseek,
 698};
 699
 700/*
 701 * payload - write methods
 702 * If the method has a response, the response should be put in buf,
 703 * and the length returned.  Otherwise return 0 or and -error.
 704 */
 705
 706static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 707{
 708        char *scon = NULL, *tcon = NULL;
 709        u32 ssid, tsid;
 710        u16 tclass;
 711        struct av_decision avd;
 712        ssize_t length;
 713
 714        length = task_has_security(current, SECURITY__COMPUTE_AV);
 715        if (length)
 716                goto out;
 717
 718        length = -ENOMEM;
 719        scon = kzalloc(size + 1, GFP_KERNEL);
 720        if (!scon)
 721                goto out;
 722
 723        length = -ENOMEM;
 724        tcon = kzalloc(size + 1, GFP_KERNEL);
 725        if (!tcon)
 726                goto out;
 727
 728        length = -EINVAL;
 729        if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 730                goto out;
 731
 732        length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 733        if (length)
 734                goto out;
 735
 736        length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 737        if (length)
 738                goto out;
 739
 740        security_compute_av_user(ssid, tsid, tclass, &avd);
 741
 742        length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 743                          "%x %x %x %x %u %x",
 744                          avd.allowed, 0xffffffff,
 745                          avd.auditallow, avd.auditdeny,
 746                          avd.seqno, avd.flags);
 747out:
 748        kfree(tcon);
 749        kfree(scon);
 750        return length;
 751}
 752
 753static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 754{
 755        char *scon = NULL, *tcon = NULL;
 756        char *namebuf = NULL, *objname = NULL;
 757        u32 ssid, tsid, newsid;
 758        u16 tclass;
 759        ssize_t length;
 760        char *newcon = NULL;
 761        u32 len;
 762        int nargs;
 763
 764        length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 765        if (length)
 766                goto out;
 767
 768        length = -ENOMEM;
 769        scon = kzalloc(size + 1, GFP_KERNEL);
 770        if (!scon)
 771                goto out;
 772
 773        length = -ENOMEM;
 774        tcon = kzalloc(size + 1, GFP_KERNEL);
 775        if (!tcon)
 776                goto out;
 777
 778        length = -ENOMEM;
 779        namebuf = kzalloc(size + 1, GFP_KERNEL);
 780        if (!namebuf)
 781                goto out;
 782
 783        length = -EINVAL;
 784        nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 785        if (nargs < 3 || nargs > 4)
 786                goto out;
 787        if (nargs == 4) {
 788                /*
 789                 * If and when the name of new object to be queried contains
 790                 * either whitespace or multibyte characters, they shall be
 791                 * encoded based on the percentage-encoding rule.
 792                 * If not encoded, the sscanf logic picks up only left-half
 793                 * of the supplied name; splitted by a whitespace unexpectedly.
 794                 */
 795                char   *r, *w;
 796                int     c1, c2;
 797
 798                r = w = namebuf;
 799                do {
 800                        c1 = *r++;
 801                        if (c1 == '+')
 802                                c1 = ' ';
 803                        else if (c1 == '%') {
 804                                c1 = hex_to_bin(*r++);
 805                                if (c1 < 0)
 806                                        goto out;
 807                                c2 = hex_to_bin(*r++);
 808                                if (c2 < 0)
 809                                        goto out;
 810                                c1 = (c1 << 4) | c2;
 811                        }
 812                        *w++ = c1;
 813                } while (c1 != '\0');
 814
 815                objname = namebuf;
 816        }
 817
 818        length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 819        if (length)
 820                goto out;
 821
 822        length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 823        if (length)
 824                goto out;
 825
 826        length = security_transition_sid_user(ssid, tsid, tclass,
 827                                              objname, &newsid);
 828        if (length)
 829                goto out;
 830
 831        length = security_sid_to_context(newsid, &newcon, &len);
 832        if (length)
 833                goto out;
 834
 835        length = -ERANGE;
 836        if (len > SIMPLE_TRANSACTION_LIMIT) {
 837                printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 838                        "payload max\n", __func__, len);
 839                goto out;
 840        }
 841
 842        memcpy(buf, newcon, len);
 843        length = len;
 844out:
 845        kfree(newcon);
 846        kfree(namebuf);
 847        kfree(tcon);
 848        kfree(scon);
 849        return length;
 850}
 851
 852static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 853{
 854        char *scon = NULL, *tcon = NULL;
 855        u32 ssid, tsid, newsid;
 856        u16 tclass;
 857        ssize_t length;
 858        char *newcon = NULL;
 859        u32 len;
 860
 861        length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 862        if (length)
 863                goto out;
 864
 865        length = -ENOMEM;
 866        scon = kzalloc(size + 1, GFP_KERNEL);
 867        if (!scon)
 868                goto out;
 869
 870        length = -ENOMEM;
 871        tcon = kzalloc(size + 1, GFP_KERNEL);
 872        if (!tcon)
 873                goto out;
 874
 875        length = -EINVAL;
 876        if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 877                goto out;
 878
 879        length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 880        if (length)
 881                goto out;
 882
 883        length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
 884        if (length)
 885                goto out;
 886
 887        length = security_change_sid(ssid, tsid, tclass, &newsid);
 888        if (length)
 889                goto out;
 890
 891        length = security_sid_to_context(newsid, &newcon, &len);
 892        if (length)
 893                goto out;
 894
 895        length = -ERANGE;
 896        if (len > SIMPLE_TRANSACTION_LIMIT)
 897                goto out;
 898
 899        memcpy(buf, newcon, len);
 900        length = len;
 901out:
 902        kfree(newcon);
 903        kfree(tcon);
 904        kfree(scon);
 905        return length;
 906}
 907
 908static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 909{
 910        char *con = NULL, *user = NULL, *ptr;
 911        u32 sid, *sids = NULL;
 912        ssize_t length;
 913        char *newcon;
 914        int i, rc;
 915        u32 len, nsids;
 916
 917        length = task_has_security(current, SECURITY__COMPUTE_USER);
 918        if (length)
 919                goto out;
 920
 921        length = -ENOMEM;
 922        con = kzalloc(size + 1, GFP_KERNEL);
 923        if (!con)
 924                goto out;
 925
 926        length = -ENOMEM;
 927        user = kzalloc(size + 1, GFP_KERNEL);
 928        if (!user)
 929                goto out;
 930
 931        length = -EINVAL;
 932        if (sscanf(buf, "%s %s", con, user) != 2)
 933                goto out;
 934
 935        length = security_context_to_sid(con, strlen(con) + 1, &sid);
 936        if (length)
 937                goto out;
 938
 939        length = security_get_user_sids(sid, user, &sids, &nsids);
 940        if (length)
 941                goto out;
 942
 943        length = sprintf(buf, "%u", nsids) + 1;
 944        ptr = buf + length;
 945        for (i = 0; i < nsids; i++) {
 946                rc = security_sid_to_context(sids[i], &newcon, &len);
 947                if (rc) {
 948                        length = rc;
 949                        goto out;
 950                }
 951                if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 952                        kfree(newcon);
 953                        length = -ERANGE;
 954                        goto out;
 955                }
 956                memcpy(ptr, newcon, len);
 957                kfree(newcon);
 958                ptr += len;
 959                length += len;
 960        }
 961out:
 962        kfree(sids);
 963        kfree(user);
 964        kfree(con);
 965        return length;
 966}
 967
 968static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 969{
 970        char *scon = NULL, *tcon = NULL;
 971        u32 ssid, tsid, newsid;
 972        u16 tclass;
 973        ssize_t length;
 974        char *newcon = NULL;
 975        u32 len;
 976
 977        length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 978        if (length)
 979                goto out;
 980
 981        length = -ENOMEM;
 982        scon = kzalloc(size + 1, GFP_KERNEL);
 983        if (!scon)
 984                goto out;
 985
 986        length = -ENOMEM;
 987        tcon = kzalloc(size + 1, GFP_KERNEL);
 988        if (!tcon)
 989                goto out;
 990
 991        length = -EINVAL;
 992        if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 993                goto out;
 994
 995        length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
 996        if (length)
 997                goto out;
 998
 999        length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1000        if (length)
1001                goto out;
1002
1003        length = security_member_sid(ssid, tsid, tclass, &newsid);
1004        if (length)
1005                goto out;
1006
1007        length = security_sid_to_context(newsid, &newcon, &len);
1008        if (length)
1009                goto out;
1010
1011        length = -ERANGE;
1012        if (len > SIMPLE_TRANSACTION_LIMIT) {
1013                printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1014                        "payload max\n", __func__, len);
1015                goto out;
1016        }
1017
1018        memcpy(buf, newcon, len);
1019        length = len;
1020out:
1021        kfree(newcon);
1022        kfree(tcon);
1023        kfree(scon);
1024        return length;
1025}
1026
1027static struct inode *sel_make_inode(struct super_block *sb, int mode)
1028{
1029        struct inode *ret = new_inode(sb);
1030
1031        if (ret) {
1032                ret->i_mode = mode;
1033                ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1034        }
1035        return ret;
1036}
1037
1038static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1039                             size_t count, loff_t *ppos)
1040{
1041        char *page = NULL;
1042        ssize_t length;
1043        ssize_t ret;
1044        int cur_enforcing;
1045        unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1046        const char *name = filep->f_path.dentry->d_name.name;
1047
1048        mutex_lock(&sel_mutex);
1049
1050        ret = -EINVAL;
1051        if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1052                goto out;
1053
1054        ret = -ENOMEM;
1055        page = (char *)get_zeroed_page(GFP_KERNEL);
1056        if (!page)
1057                goto out;
1058
1059        cur_enforcing = security_get_bool_value(index);
1060        if (cur_enforcing < 0) {
1061                ret = cur_enforcing;
1062                goto out;
1063        }
1064        length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1065                          bool_pending_values[index]);
1066        ret = simple_read_from_buffer(buf, count, ppos, page, length);
1067out:
1068        mutex_unlock(&sel_mutex);
1069        free_page((unsigned long)page);
1070        return ret;
1071}
1072
1073static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1074                              size_t count, loff_t *ppos)
1075{
1076        char *page = NULL;
1077        ssize_t length;
1078        int new_value;
1079        unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1080        const char *name = filep->f_path.dentry->d_name.name;
1081
1082        mutex_lock(&sel_mutex);
1083
1084        length = task_has_security(current, SECURITY__SETBOOL);
1085        if (length)
1086                goto out;
1087
1088        length = -EINVAL;
1089        if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1090                goto out;
1091
1092        length = -ENOMEM;
1093        if (count >= PAGE_SIZE)
1094                goto out;
1095
1096        /* No partial writes. */
1097        length = -EINVAL;
1098        if (*ppos != 0)
1099                goto out;
1100
1101        length = -ENOMEM;
1102        page = (char *)get_zeroed_page(GFP_KERNEL);
1103        if (!page)
1104                goto out;
1105
1106        length = -EFAULT;
1107        if (copy_from_user(page, buf, count))
1108                goto out;
1109
1110        length = -EINVAL;
1111        if (sscanf(page, "%d", &new_value) != 1)
1112                goto out;
1113
1114        if (new_value)
1115                new_value = 1;
1116
1117        bool_pending_values[index] = new_value;
1118        length = count;
1119
1120out:
1121        mutex_unlock(&sel_mutex);
1122        free_page((unsigned long) page);
1123        return length;
1124}
1125
1126static const struct file_operations sel_bool_ops = {
1127        .read           = sel_read_bool,
1128        .write          = sel_write_bool,
1129        .llseek         = generic_file_llseek,
1130};
1131
1132static ssize_t sel_commit_bools_write(struct file *filep,
1133                                      const char __user *buf,
1134                                      size_t count, loff_t *ppos)
1135{
1136        char *page = NULL;
1137        ssize_t length;
1138        int new_value;
1139
1140        mutex_lock(&sel_mutex);
1141
1142        length = task_has_security(current, SECURITY__SETBOOL);
1143        if (length)
1144                goto out;
1145
1146        length = -ENOMEM;
1147        if (count >= PAGE_SIZE)
1148                goto out;
1149
1150        /* No partial writes. */
1151        length = -EINVAL;
1152        if (*ppos != 0)
1153                goto out;
1154
1155        length = -ENOMEM;
1156        page = (char *)get_zeroed_page(GFP_KERNEL);
1157        if (!page)
1158                goto out;
1159
1160        length = -EFAULT;
1161        if (copy_from_user(page, buf, count))
1162                goto out;
1163
1164        length = -EINVAL;
1165        if (sscanf(page, "%d", &new_value) != 1)
1166                goto out;
1167
1168        length = 0;
1169        if (new_value && bool_pending_values)
1170                length = security_set_bools(bool_num, bool_pending_values);
1171
1172        if (!length)
1173                length = count;
1174
1175out:
1176        mutex_unlock(&sel_mutex);
1177        free_page((unsigned long) page);
1178        return length;
1179}
1180
1181static const struct file_operations sel_commit_bools_ops = {
1182        .write          = sel_commit_bools_write,
1183        .llseek         = generic_file_llseek,
1184};
1185
1186static void sel_remove_entries(struct dentry *de)
1187{
1188        struct list_head *node;
1189
1190        spin_lock(&de->d_lock);
1191        node = de->d_subdirs.next;
1192        while (node != &de->d_subdirs) {
1193                struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1194
1195                spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1196                list_del_init(node);
1197
1198                if (d->d_inode) {
1199                        dget_dlock(d);
1200                        spin_unlock(&de->d_lock);
1201                        spin_unlock(&d->d_lock);
1202                        d_delete(d);
1203                        simple_unlink(de->d_inode, d);
1204                        dput(d);
1205                        spin_lock(&de->d_lock);
1206                } else
1207                        spin_unlock(&d->d_lock);
1208                node = de->d_subdirs.next;
1209        }
1210
1211        spin_unlock(&de->d_lock);
1212}
1213
1214#define BOOL_DIR_NAME "booleans"
1215
1216static int sel_make_bools(void)
1217{
1218        int i, ret;
1219        ssize_t len;
1220        struct dentry *dentry = NULL;
1221        struct dentry *dir = bool_dir;
1222        struct inode *inode = NULL;
1223        struct inode_security_struct *isec;
1224        char **names = NULL, *page;
1225        int num;
1226        int *values = NULL;
1227        u32 sid;
1228
1229        /* remove any existing files */
1230        for (i = 0; i < bool_num; i++)
1231                kfree(bool_pending_names[i]);
1232        kfree(bool_pending_names);
1233        kfree(bool_pending_values);
1234        bool_num = 0;
1235        bool_pending_names = NULL;
1236        bool_pending_values = NULL;
1237
1238        sel_remove_entries(dir);
1239
1240        ret = -ENOMEM;
1241        page = (char *)get_zeroed_page(GFP_KERNEL);
1242        if (!page)
1243                goto out;
1244
1245        ret = security_get_bools(&num, &names, &values);
1246        if (ret)
1247                goto out;
1248
1249        for (i = 0; i < num; i++) {
1250                ret = -ENOMEM;
1251                dentry = d_alloc_name(dir, names[i]);
1252                if (!dentry)
1253                        goto out;
1254
1255                ret = -ENOMEM;
1256                inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1257                if (!inode)
1258                        goto out;
1259
1260                ret = -ENAMETOOLONG;
1261                len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1262                if (len >= PAGE_SIZE)
1263                        goto out;
1264
1265                isec = (struct inode_security_struct *)inode->i_security;
1266                ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1267                if (ret)
1268                        goto out;
1269
1270                isec->sid = sid;
1271                isec->initialized = 1;
1272                inode->i_fop = &sel_bool_ops;
1273                inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1274                d_add(dentry, inode);
1275        }
1276        bool_num = num;
1277        bool_pending_names = names;
1278        bool_pending_values = values;
1279
1280        free_page((unsigned long)page);
1281        return 0;
1282out:
1283        free_page((unsigned long)page);
1284
1285        if (names) {
1286                for (i = 0; i < num; i++)
1287                        kfree(names[i]);
1288                kfree(names);
1289        }
1290        kfree(values);
1291        sel_remove_entries(dir);
1292
1293        return ret;
1294}
1295
1296#define NULL_FILE_NAME "null"
1297
1298struct path selinux_null;
1299
1300static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1301                                            size_t count, loff_t *ppos)
1302{
1303        char tmpbuf[TMPBUFLEN];
1304        ssize_t length;
1305
1306        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1307        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1308}
1309
1310static ssize_t sel_write_avc_cache_threshold(struct file *file,
1311                                             const char __user *buf,
1312                                             size_t count, loff_t *ppos)
1313
1314{
1315        char *page = NULL;
1316        ssize_t ret;
1317        int new_value;
1318
1319        ret = task_has_security(current, SECURITY__SETSECPARAM);
1320        if (ret)
1321                goto out;
1322
1323        ret = -ENOMEM;
1324        if (count >= PAGE_SIZE)
1325                goto out;
1326
1327        /* No partial writes. */
1328        ret = -EINVAL;
1329        if (*ppos != 0)
1330                goto out;
1331
1332        ret = -ENOMEM;
1333        page = (char *)get_zeroed_page(GFP_KERNEL);
1334        if (!page)
1335                goto out;
1336
1337        ret = -EFAULT;
1338        if (copy_from_user(page, buf, count))
1339                goto out;
1340
1341        ret = -EINVAL;
1342        if (sscanf(page, "%u", &new_value) != 1)
1343                goto out;
1344
1345        avc_cache_threshold = new_value;
1346
1347        ret = count;
1348out:
1349        free_page((unsigned long)page);
1350        return ret;
1351}
1352
1353static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1354                                       size_t count, loff_t *ppos)
1355{
1356        char *page;
1357        ssize_t length;
1358
1359        page = (char *)__get_free_page(GFP_KERNEL);
1360        if (!page)
1361                return -ENOMEM;
1362
1363        length = avc_get_hash_stats(page);
1364        if (length >= 0)
1365                length = simple_read_from_buffer(buf, count, ppos, page, length);
1366        free_page((unsigned long)page);
1367
1368        return length;
1369}
1370
1371static const struct file_operations sel_avc_cache_threshold_ops = {
1372        .read           = sel_read_avc_cache_threshold,
1373        .write          = sel_write_avc_cache_threshold,
1374        .llseek         = generic_file_llseek,
1375};
1376
1377static const struct file_operations sel_avc_hash_stats_ops = {
1378        .read           = sel_read_avc_hash_stats,
1379        .llseek         = generic_file_llseek,
1380};
1381
1382#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1383static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1384{
1385        int cpu;
1386
1387        for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1388                if (!cpu_possible(cpu))
1389                        continue;
1390                *idx = cpu + 1;
1391                return &per_cpu(avc_cache_stats, cpu);
1392        }
1393        return NULL;
1394}
1395
1396static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1397{
1398        loff_t n = *pos - 1;
1399
1400        if (*pos == 0)
1401                return SEQ_START_TOKEN;
1402
1403        return sel_avc_get_stat_idx(&n);
1404}
1405
1406static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1407{
1408        return sel_avc_get_stat_idx(pos);
1409}
1410
1411static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1412{
1413        struct avc_cache_stats *st = v;
1414
1415        if (v == SEQ_START_TOKEN)
1416                seq_printf(seq, "lookups hits misses allocations reclaims "
1417                           "frees\n");
1418        else {
1419                unsigned int lookups = st->lookups;
1420                unsigned int misses = st->misses;
1421                unsigned int hits = lookups - misses;
1422                seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1423                           hits, misses, st->allocations,
1424                           st->reclaims, st->frees);
1425        }
1426        return 0;
1427}
1428
1429static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1430{ }
1431
1432static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1433        .start          = sel_avc_stats_seq_start,
1434        .next           = sel_avc_stats_seq_next,
1435        .show           = sel_avc_stats_seq_show,
1436        .stop           = sel_avc_stats_seq_stop,
1437};
1438
1439static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1440{
1441        return seq_open(file, &sel_avc_cache_stats_seq_ops);
1442}
1443
1444static const struct file_operations sel_avc_cache_stats_ops = {
1445        .open           = sel_open_avc_cache_stats,
1446        .read           = seq_read,
1447        .llseek         = seq_lseek,
1448        .release        = seq_release,
1449};
1450#endif
1451
1452static int sel_make_avc_files(struct dentry *dir)
1453{
1454        int i;
1455        static struct tree_descr files[] = {
1456                { "cache_threshold",
1457                  &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1458                { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1459#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1460                { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1461#endif
1462        };
1463
1464        for (i = 0; i < ARRAY_SIZE(files); i++) {
1465                struct inode *inode;
1466                struct dentry *dentry;
1467
1468                dentry = d_alloc_name(dir, files[i].name);
1469                if (!dentry)
1470                        return -ENOMEM;
1471
1472                inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1473                if (!inode)
1474                        return -ENOMEM;
1475
1476                inode->i_fop = files[i].ops;
1477                inode->i_ino = ++sel_last_ino;
1478                d_add(dentry, inode);
1479        }
1480
1481        return 0;
1482}
1483
1484static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1485                                size_t count, loff_t *ppos)
1486{
1487        char *con;
1488        u32 sid, len;
1489        ssize_t ret;
1490
1491        sid = file_inode(file)->i_ino&SEL_INO_MASK;
1492        ret = security_sid_to_context(sid, &con, &len);
1493        if (ret)
1494                return ret;
1495
1496        ret = simple_read_from_buffer(buf, count, ppos, con, len);
1497        kfree(con);
1498        return ret;
1499}
1500
1501static const struct file_operations sel_initcon_ops = {
1502        .read           = sel_read_initcon,
1503        .llseek         = generic_file_llseek,
1504};
1505
1506static int sel_make_initcon_files(struct dentry *dir)
1507{
1508        int i;
1509
1510        for (i = 1; i <= SECINITSID_NUM; i++) {
1511                struct inode *inode;
1512                struct dentry *dentry;
1513                dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1514                if (!dentry)
1515                        return -ENOMEM;
1516
1517                inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1518                if (!inode)
1519                        return -ENOMEM;
1520
1521                inode->i_fop = &sel_initcon_ops;
1522                inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1523                d_add(dentry, inode);
1524        }
1525
1526        return 0;
1527}
1528
1529static inline unsigned long sel_class_to_ino(u16 class)
1530{
1531        return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1532}
1533
1534static inline u16 sel_ino_to_class(unsigned long ino)
1535{
1536        return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1537}
1538
1539static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1540{
1541        return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1542}
1543
1544static inline u32 sel_ino_to_perm(unsigned long ino)
1545{
1546        return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1547}
1548
1549static ssize_t sel_read_class(struct file *file, char __user *buf,
1550                                size_t count, loff_t *ppos)
1551{
1552        unsigned long ino = file_inode(file)->i_ino;
1553        char res[TMPBUFLEN];
1554        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1555        return simple_read_from_buffer(buf, count, ppos, res, len);
1556}
1557
1558static const struct file_operations sel_class_ops = {
1559        .read           = sel_read_class,
1560        .llseek         = generic_file_llseek,
1561};
1562
1563static ssize_t sel_read_perm(struct file *file, char __user *buf,
1564                                size_t count, loff_t *ppos)
1565{
1566        unsigned long ino = file_inode(file)->i_ino;
1567        char res[TMPBUFLEN];
1568        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1569        return simple_read_from_buffer(buf, count, ppos, res, len);
1570}
1571
1572static const struct file_operations sel_perm_ops = {
1573        .read           = sel_read_perm,
1574        .llseek         = generic_file_llseek,
1575};
1576
1577static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1578                                  size_t count, loff_t *ppos)
1579{
1580        int value;
1581        char tmpbuf[TMPBUFLEN];
1582        ssize_t length;
1583        unsigned long i_ino = file_inode(file)->i_ino;
1584
1585        value = security_policycap_supported(i_ino & SEL_INO_MASK);
1586        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1587
1588        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1589}
1590
1591static const struct file_operations sel_policycap_ops = {
1592        .read           = sel_read_policycap,
1593        .llseek         = generic_file_llseek,
1594};
1595
1596static int sel_make_perm_files(char *objclass, int classvalue,
1597                                struct dentry *dir)
1598{
1599        int i, rc, nperms;
1600        char **perms;
1601
1602        rc = security_get_permissions(objclass, &perms, &nperms);
1603        if (rc)
1604                return rc;
1605
1606        for (i = 0; i < nperms; i++) {
1607                struct inode *inode;
1608                struct dentry *dentry;
1609
1610                rc = -ENOMEM;
1611                dentry = d_alloc_name(dir, perms[i]);
1612                if (!dentry)
1613                        goto out;
1614
1615                rc = -ENOMEM;
1616                inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1617                if (!inode)
1618                        goto out;
1619
1620                inode->i_fop = &sel_perm_ops;
1621                /* i+1 since perm values are 1-indexed */
1622                inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1623                d_add(dentry, inode);
1624        }
1625        rc = 0;
1626out:
1627        for (i = 0; i < nperms; i++)
1628                kfree(perms[i]);
1629        kfree(perms);
1630        return rc;
1631}
1632
1633static int sel_make_class_dir_entries(char *classname, int index,
1634                                        struct dentry *dir)
1635{
1636        struct dentry *dentry = NULL;
1637        struct inode *inode = NULL;
1638        int rc;
1639
1640        dentry = d_alloc_name(dir, "index");
1641        if (!dentry)
1642                return -ENOMEM;
1643
1644        inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1645        if (!inode)
1646                return -ENOMEM;
1647
1648        inode->i_fop = &sel_class_ops;
1649        inode->i_ino = sel_class_to_ino(index);
1650        d_add(dentry, inode);
1651
1652        dentry = sel_make_dir(dir, "perms", &last_class_ino);
1653        if (IS_ERR(dentry))
1654                return PTR_ERR(dentry);
1655
1656        rc = sel_make_perm_files(classname, index, dentry);
1657
1658        return rc;
1659}
1660
1661static void sel_remove_classes(void)
1662{
1663        struct list_head *class_node;
1664
1665        list_for_each(class_node, &class_dir->d_subdirs) {
1666                struct dentry *class_subdir = list_entry(class_node,
1667                                        struct dentry, d_u.d_child);
1668                struct list_head *class_subdir_node;
1669
1670                list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1671                        struct dentry *d = list_entry(class_subdir_node,
1672                                                struct dentry, d_u.d_child);
1673
1674                        if (d->d_inode)
1675                                if (d->d_inode->i_mode & S_IFDIR)
1676                                        sel_remove_entries(d);
1677                }
1678
1679                sel_remove_entries(class_subdir);
1680        }
1681
1682        sel_remove_entries(class_dir);
1683}
1684
1685static int sel_make_classes(void)
1686{
1687        int rc, nclasses, i;
1688        char **classes;
1689
1690        /* delete any existing entries */
1691        sel_remove_classes();
1692
1693        rc = security_get_classes(&classes, &nclasses);
1694        if (rc)
1695                return rc;
1696
1697        /* +2 since classes are 1-indexed */
1698        last_class_ino = sel_class_to_ino(nclasses + 2);
1699
1700        for (i = 0; i < nclasses; i++) {
1701                struct dentry *class_name_dir;
1702
1703                class_name_dir = sel_make_dir(class_dir, classes[i],
1704                                &last_class_ino);
1705                if (IS_ERR(class_name_dir)) {
1706                        rc = PTR_ERR(class_name_dir);
1707                        goto out;
1708                }
1709
1710                /* i+1 since class values are 1-indexed */
1711                rc = sel_make_class_dir_entries(classes[i], i + 1,
1712                                class_name_dir);
1713                if (rc)
1714                        goto out;
1715        }
1716        rc = 0;
1717out:
1718        for (i = 0; i < nclasses; i++)
1719                kfree(classes[i]);
1720        kfree(classes);
1721        return rc;
1722}
1723
1724static int sel_make_policycap(void)
1725{
1726        unsigned int iter;
1727        struct dentry *dentry = NULL;
1728        struct inode *inode = NULL;
1729
1730        sel_remove_entries(policycap_dir);
1731
1732        for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1733                if (iter < ARRAY_SIZE(policycap_names))
1734                        dentry = d_alloc_name(policycap_dir,
1735                                              policycap_names[iter]);
1736                else
1737                        dentry = d_alloc_name(policycap_dir, "unknown");
1738
1739                if (dentry == NULL)
1740                        return -ENOMEM;
1741
1742                inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1743                if (inode == NULL)
1744                        return -ENOMEM;
1745
1746                inode->i_fop = &sel_policycap_ops;
1747                inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1748                d_add(dentry, inode);
1749        }
1750
1751        return 0;
1752}
1753
1754static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1755                        unsigned long *ino)
1756{
1757        struct dentry *dentry = d_alloc_name(dir, name);
1758        struct inode *inode;
1759
1760        if (!dentry)
1761                return ERR_PTR(-ENOMEM);
1762
1763        inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1764        if (!inode) {
1765                dput(dentry);
1766                return ERR_PTR(-ENOMEM);
1767        }
1768
1769        inode->i_op = &simple_dir_inode_operations;
1770        inode->i_fop = &simple_dir_operations;
1771        inode->i_ino = ++(*ino);
1772        /* directory inodes start off with i_nlink == 2 (for "." entry) */
1773        inc_nlink(inode);
1774        d_add(dentry, inode);
1775        /* bump link count on parent directory, too */
1776        inc_nlink(dir->d_inode);
1777
1778        return dentry;
1779}
1780
1781static int sel_fill_super(struct super_block *sb, void *data, int silent)
1782{
1783        int ret;
1784        struct dentry *dentry;
1785        struct inode *inode;
1786        struct inode_security_struct *isec;
1787
1788        static struct tree_descr selinux_files[] = {
1789                [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1790                [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1791                [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1792                [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1793                [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1794                [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1795                [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1796                [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1797                [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1798                [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1799                [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1800                [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1801                [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1802                [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1803                [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1804                [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1805                [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1806                /* last one */ {""}
1807        };
1808        ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1809        if (ret)
1810                goto err;
1811
1812        bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1813        if (IS_ERR(bool_dir)) {
1814                ret = PTR_ERR(bool_dir);
1815                bool_dir = NULL;
1816                goto err;
1817        }
1818
1819        ret = -ENOMEM;
1820        dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1821        if (!dentry)
1822                goto err;
1823
1824        ret = -ENOMEM;
1825        inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1826        if (!inode)
1827                goto err;
1828
1829        inode->i_ino = ++sel_last_ino;
1830        isec = (struct inode_security_struct *)inode->i_security;
1831        isec->sid = SECINITSID_DEVNULL;
1832        isec->sclass = SECCLASS_CHR_FILE;
1833        isec->initialized = 1;
1834
1835        init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1836        d_add(dentry, inode);
1837        selinux_null.dentry = dentry;
1838
1839        dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1840        if (IS_ERR(dentry)) {
1841                ret = PTR_ERR(dentry);
1842                goto err;
1843        }
1844
1845        ret = sel_make_avc_files(dentry);
1846        if (ret)
1847                goto err;
1848
1849        dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1850        if (IS_ERR(dentry)) {
1851                ret = PTR_ERR(dentry);
1852                goto err;
1853        }
1854
1855        ret = sel_make_initcon_files(dentry);
1856        if (ret)
1857                goto err;
1858
1859        class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1860        if (IS_ERR(class_dir)) {
1861                ret = PTR_ERR(class_dir);
1862                class_dir = NULL;
1863                goto err;
1864        }
1865
1866        policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1867        if (IS_ERR(policycap_dir)) {
1868                ret = PTR_ERR(policycap_dir);
1869                policycap_dir = NULL;
1870                goto err;
1871        }
1872        return 0;
1873err:
1874        printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1875                __func__);
1876        return ret;
1877}
1878
1879static struct dentry *sel_mount(struct file_system_type *fs_type,
1880                      int flags, const char *dev_name, void *data)
1881{
1882        return mount_single(fs_type, flags, data, sel_fill_super);
1883}
1884
1885static struct file_system_type sel_fs_type = {
1886        .name           = "selinuxfs",
1887        .mount          = sel_mount,
1888        .kill_sb        = kill_litter_super,
1889};
1890
1891struct vfsmount *selinuxfs_mount;
1892static struct kobject *selinuxfs_kobj;
1893
1894static int __init init_sel_fs(void)
1895{
1896        int err;
1897
1898        if (!selinux_enabled)
1899                return 0;
1900
1901        selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1902        if (!selinuxfs_kobj)
1903                return -ENOMEM;
1904
1905        err = register_filesystem(&sel_fs_type);
1906        if (err) {
1907                kobject_put(selinuxfs_kobj);
1908                return err;
1909        }
1910
1911        selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1912        if (IS_ERR(selinuxfs_mount)) {
1913                printk(KERN_ERR "selinuxfs:  could not mount!\n");
1914                err = PTR_ERR(selinuxfs_mount);
1915                selinuxfs_mount = NULL;
1916        }
1917
1918        return err;
1919}
1920
1921__initcall(init_sel_fs);
1922
1923#ifdef CONFIG_SECURITY_SELINUX_DISABLE
1924void exit_sel_fs(void)
1925{
1926        kobject_put(selinuxfs_kobj);
1927        kern_unmount(selinuxfs_mount);
1928        unregister_filesystem(&sel_fs_type);
1929}
1930#endif
1931