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        "redhat1",
  49        "always_check_network"
  50};
  51
  52unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
  53
  54static int __init checkreqprot_setup(char *str)
  55{
  56        unsigned long checkreqprot;
  57        if (!kstrtoul(str, 0, &checkreqprot))
  58                selinux_checkreqprot = checkreqprot ? 1 : 0;
  59        return 1;
  60}
  61__setup("checkreqprot=", checkreqprot_setup);
  62
  63static DEFINE_MUTEX(sel_mutex);
  64
  65/* global data for booleans */
  66static struct dentry *bool_dir;
  67static int bool_num;
  68static char **bool_pending_names;
  69static int *bool_pending_values;
  70
  71/* global data for classes */
  72static struct dentry *class_dir;
  73static unsigned long last_class_ino;
  74
  75static char policy_opened;
  76
  77/* global data for policy capabilities */
  78static struct dentry *policycap_dir;
  79
  80/* Check whether a task is allowed to use a security operation. */
  81static int task_has_security(struct task_struct *tsk,
  82                             u32 perms)
  83{
  84        const struct task_security_struct *tsec;
  85        u32 sid = 0;
  86
  87        rcu_read_lock();
  88        tsec = __task_cred(tsk)->security;
  89        if (tsec)
  90                sid = tsec->sid;
  91        rcu_read_unlock();
  92        if (!tsec)
  93                return -EACCES;
  94
  95        return avc_has_perm(sid, SECINITSID_SECURITY,
  96                            SECCLASS_SECURITY, perms, NULL);
  97}
  98
  99enum sel_inos {
 100        SEL_ROOT_INO = 2,
 101        SEL_LOAD,       /* load policy */
 102        SEL_ENFORCE,    /* get or set enforcing status */
 103        SEL_CONTEXT,    /* validate context */
 104        SEL_ACCESS,     /* compute access decision */
 105        SEL_CREATE,     /* compute create labeling decision */
 106        SEL_RELABEL,    /* compute relabeling decision */
 107        SEL_USER,       /* compute reachable user contexts */
 108        SEL_POLICYVERS, /* return policy version for this kernel */
 109        SEL_COMMIT_BOOLS, /* commit new boolean values */
 110        SEL_MLS,        /* return if MLS policy is enabled */
 111        SEL_DISABLE,    /* disable SELinux until next reboot */
 112        SEL_MEMBER,     /* compute polyinstantiation membership decision */
 113        SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
 114        SEL_COMPAT_NET, /* whether to use old compat network packet controls */
 115        SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
 116        SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 117        SEL_STATUS,     /* export current status using mmap() */
 118        SEL_POLICY,     /* allow userspace to read the in kernel policy */
 119        SEL_INO_NEXT,   /* The next inode number to use */
 120};
 121
 122static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
 123
 124#define SEL_INITCON_INO_OFFSET          0x01000000
 125#define SEL_BOOL_INO_OFFSET             0x02000000
 126#define SEL_CLASS_INO_OFFSET            0x04000000
 127#define SEL_POLICYCAP_INO_OFFSET        0x08000000
 128#define SEL_INO_MASK                    0x00ffffff
 129
 130#define TMPBUFLEN       12
 131static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
 132                                size_t count, loff_t *ppos)
 133{
 134        char tmpbuf[TMPBUFLEN];
 135        ssize_t length;
 136
 137        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
 138        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 139}
 140
 141#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 142static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 143                                 size_t count, loff_t *ppos)
 144
 145{
 146        char *page = NULL;
 147        ssize_t length;
 148        int new_value;
 149
 150        length = -ENOMEM;
 151        if (count >= PAGE_SIZE)
 152                goto out;
 153
 154        /* No partial writes. */
 155        length = -EINVAL;
 156        if (*ppos != 0)
 157                goto out;
 158
 159        length = -ENOMEM;
 160        page = (char *)get_zeroed_page(GFP_KERNEL);
 161        if (!page)
 162                goto out;
 163
 164        length = -EFAULT;
 165        if (copy_from_user(page, buf, count))
 166                goto out;
 167
 168        length = -EINVAL;
 169        if (sscanf(page, "%d", &new_value) != 1)
 170                goto out;
 171
 172        if (new_value != selinux_enforcing) {
 173                length = task_has_security(current, SECURITY__SETENFORCE);
 174                if (length)
 175                        goto out;
 176                audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 177                        "enforcing=%d old_enforcing=%d auid=%u ses=%u",
 178                        new_value, selinux_enforcing,
 179                        from_kuid(&init_user_ns, audit_get_loginuid(current)),
 180                        audit_get_sessionid(current));
 181                selinux_enforcing = new_value;
 182                if (selinux_enforcing)
 183                        avc_ss_reset(0);
 184                selnl_notify_setenforce(selinux_enforcing);
 185                selinux_status_update_setenforce(selinux_enforcing);
 186        }
 187        length = count;
 188out:
 189        free_page((unsigned long) page);
 190        return length;
 191}
 192#else
 193#define sel_write_enforce NULL
 194#endif
 195
 196static const struct file_operations sel_enforce_ops = {
 197        .read           = sel_read_enforce,
 198        .write          = sel_write_enforce,
 199        .llseek         = generic_file_llseek,
 200};
 201
 202static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
 203                                        size_t count, loff_t *ppos)
 204{
 205        char tmpbuf[TMPBUFLEN];
 206        ssize_t length;
 207        ino_t ino = file_inode(filp)->i_ino;
 208        int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
 209                security_get_reject_unknown() : !security_get_allow_unknown();
 210
 211        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
 212        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 213}
 214
 215static const struct file_operations sel_handle_unknown_ops = {
 216        .read           = sel_read_handle_unknown,
 217        .llseek         = generic_file_llseek,
 218};
 219
 220static int sel_open_handle_status(struct inode *inode, struct file *filp)
 221{
 222        struct page    *status = selinux_kernel_status_page();
 223
 224        if (!status)
 225                return -ENOMEM;
 226
 227        filp->private_data = status;
 228
 229        return 0;
 230}
 231
 232static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
 233                                      size_t count, loff_t *ppos)
 234{
 235        struct page    *status = filp->private_data;
 236
 237        BUG_ON(!status);
 238
 239        return simple_read_from_buffer(buf, count, ppos,
 240                                       page_address(status),
 241                                       sizeof(struct selinux_kernel_status));
 242}
 243
 244static int sel_mmap_handle_status(struct file *filp,
 245                                  struct vm_area_struct *vma)
 246{
 247        struct page    *status = filp->private_data;
 248        unsigned long   size = vma->vm_end - vma->vm_start;
 249
 250        BUG_ON(!status);
 251
 252        /* only allows one page from the head */
 253        if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
 254                return -EIO;
 255        /* disallow writable mapping */
 256        if (vma->vm_flags & VM_WRITE)
 257                return -EPERM;
 258        /* disallow mprotect() turns it into writable */
 259        vma->vm_flags &= ~VM_MAYWRITE;
 260
 261        return remap_pfn_range(vma, vma->vm_start,
 262                               page_to_pfn(status),
 263                               size, vma->vm_page_prot);
 264}
 265
 266static const struct file_operations sel_handle_status_ops = {
 267        .open           = sel_open_handle_status,
 268        .read           = sel_read_handle_status,
 269        .mmap           = sel_mmap_handle_status,
 270        .llseek         = generic_file_llseek,
 271};
 272
 273#ifdef CONFIG_SECURITY_SELINUX_DISABLE
 274static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 275                                 size_t count, loff_t *ppos)
 276
 277{
 278        char *page = NULL;
 279        ssize_t length;
 280        int new_value;
 281
 282        length = -ENOMEM;
 283        if (count >= PAGE_SIZE)
 284                goto out;
 285
 286        /* No partial writes. */
 287        length = -EINVAL;
 288        if (*ppos != 0)
 289                goto out;
 290
 291        length = -ENOMEM;
 292        page = (char *)get_zeroed_page(GFP_KERNEL);
 293        if (!page)
 294                goto out;
 295
 296        length = -EFAULT;
 297        if (copy_from_user(page, buf, count))
 298                goto out;
 299
 300        length = -EINVAL;
 301        if (sscanf(page, "%d", &new_value) != 1)
 302                goto out;
 303
 304        if (new_value) {
 305                length = selinux_disable();
 306                if (length)
 307                        goto out;
 308                audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
 309                        "selinux=0 auid=%u ses=%u",
 310                        from_kuid(&init_user_ns, audit_get_loginuid(current)),
 311                        audit_get_sessionid(current));
 312        }
 313
 314        length = count;
 315out:
 316        free_page((unsigned long) page);
 317        return length;
 318}
 319#else
 320#define sel_write_disable NULL
 321#endif
 322
 323static const struct file_operations sel_disable_ops = {
 324        .write          = sel_write_disable,
 325        .llseek         = generic_file_llseek,
 326};
 327
 328static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
 329                                   size_t count, loff_t *ppos)
 330{
 331        char tmpbuf[TMPBUFLEN];
 332        ssize_t length;
 333
 334        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
 335        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 336}
 337
 338static const struct file_operations sel_policyvers_ops = {
 339        .read           = sel_read_policyvers,
 340        .llseek         = generic_file_llseek,
 341};
 342
 343/* declaration for sel_write_load */
 344static int sel_make_bools(void);
 345static int sel_make_classes(void);
 346static int sel_make_policycap(void);
 347
 348/* declaration for sel_make_class_dirs */
 349static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
 350                        unsigned long *ino);
 351
 352static ssize_t sel_read_mls(struct file *filp, char __user *buf,
 353                                size_t count, loff_t *ppos)
 354{
 355        char tmpbuf[TMPBUFLEN];
 356        ssize_t length;
 357
 358        length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
 359                           security_mls_enabled());
 360        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 361}
 362
 363static const struct file_operations sel_mls_ops = {
 364        .read           = sel_read_mls,
 365        .llseek         = generic_file_llseek,
 366};
 367
 368struct policy_load_memory {
 369        size_t len;
 370        void *data;
 371};
 372
 373static int sel_open_policy(struct inode *inode, struct file *filp)
 374{
 375        struct policy_load_memory *plm = NULL;
 376        int rc;
 377
 378        BUG_ON(filp->private_data);
 379
 380        mutex_lock(&sel_mutex);
 381
 382        rc = task_has_security(current, SECURITY__READ_POLICY);
 383        if (rc)
 384                goto err;
 385
 386        rc = -EBUSY;
 387        if (policy_opened)
 388                goto err;
 389
 390        rc = -ENOMEM;
 391        plm = kzalloc(sizeof(*plm), GFP_KERNEL);
 392        if (!plm)
 393                goto err;
 394
 395        if (i_size_read(inode) != security_policydb_len()) {
 396                mutex_lock(&inode->i_mutex);
 397                i_size_write(inode, security_policydb_len());
 398                mutex_unlock(&inode->i_mutex);
 399        }
 400
 401        rc = security_read_policy(&plm->data, &plm->len);
 402        if (rc)
 403                goto err;
 404
 405        policy_opened = 1;
 406
 407        filp->private_data = plm;
 408
 409        mutex_unlock(&sel_mutex);
 410
 411        return 0;
 412err:
 413        mutex_unlock(&sel_mutex);
 414
 415        if (plm)
 416                vfree(plm->data);
 417        kfree(plm);
 418        return rc;
 419}
 420
 421static int sel_release_policy(struct inode *inode, struct file *filp)
 422{
 423        struct policy_load_memory *plm = filp->private_data;
 424
 425        BUG_ON(!plm);
 426
 427        policy_opened = 0;
 428
 429        vfree(plm->data);
 430        kfree(plm);
 431
 432        return 0;
 433}
 434
 435static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 436                               size_t count, loff_t *ppos)
 437{
 438        struct policy_load_memory *plm = filp->private_data;
 439        int ret;
 440
 441        mutex_lock(&sel_mutex);
 442
 443        ret = task_has_security(current, SECURITY__READ_POLICY);
 444        if (ret)
 445                goto out;
 446
 447        ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
 448out:
 449        mutex_unlock(&sel_mutex);
 450        return ret;
 451}
 452
 453static int sel_mmap_policy_fault(struct vm_area_struct *vma,
 454                                 struct vm_fault *vmf)
 455{
 456        struct policy_load_memory *plm = vma->vm_file->private_data;
 457        unsigned long offset;
 458        struct page *page;
 459
 460        if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
 461                return VM_FAULT_SIGBUS;
 462
 463        offset = vmf->pgoff << PAGE_SHIFT;
 464        if (offset >= roundup(plm->len, PAGE_SIZE))
 465                return VM_FAULT_SIGBUS;
 466
 467        page = vmalloc_to_page(plm->data + offset);
 468        get_page(page);
 469
 470        vmf->page = page;
 471
 472        return 0;
 473}
 474
 475static const struct vm_operations_struct sel_mmap_policy_ops = {
 476        .fault = sel_mmap_policy_fault,
 477        .page_mkwrite = sel_mmap_policy_fault,
 478};
 479
 480static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
 481{
 482        if (vma->vm_flags & VM_SHARED) {
 483                /* do not allow mprotect to make mapping writable */
 484                vma->vm_flags &= ~VM_MAYWRITE;
 485
 486                if (vma->vm_flags & VM_WRITE)
 487                        return -EACCES;
 488        }
 489
 490        vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 491        vma->vm_ops = &sel_mmap_policy_ops;
 492
 493        return 0;
 494}
 495
 496static const struct file_operations sel_policy_ops = {
 497        .open           = sel_open_policy,
 498        .read           = sel_read_policy,
 499        .mmap           = sel_mmap_policy,
 500        .release        = sel_release_policy,
 501        .llseek         = generic_file_llseek,
 502};
 503
 504static ssize_t sel_write_load(struct file *file, const char __user *buf,
 505                              size_t count, loff_t *ppos)
 506
 507{
 508        ssize_t length;
 509        void *data = NULL;
 510
 511        mutex_lock(&sel_mutex);
 512
 513        length = task_has_security(current, SECURITY__LOAD_POLICY);
 514        if (length)
 515                goto out;
 516
 517        /* No partial writes. */
 518        length = -EINVAL;
 519        if (*ppos != 0)
 520                goto out;
 521
 522        length = -EFBIG;
 523        if (count > 64 * 1024 * 1024)
 524                goto out;
 525
 526        length = -ENOMEM;
 527        data = vmalloc(count);
 528        if (!data)
 529                goto out;
 530
 531        length = -EFAULT;
 532        if (copy_from_user(data, buf, count) != 0)
 533                goto out;
 534
 535        length = security_load_policy(data, count);
 536        if (length)
 537                goto out;
 538
 539        length = sel_make_bools();
 540        if (length)
 541                goto out1;
 542
 543        length = sel_make_classes();
 544        if (length)
 545                goto out1;
 546
 547        length = sel_make_policycap();
 548        if (length)
 549                goto out1;
 550
 551        length = count;
 552
 553out1:
 554        audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
 555                "policy loaded auid=%u ses=%u",
 556                from_kuid(&init_user_ns, audit_get_loginuid(current)),
 557                audit_get_sessionid(current));
 558out:
 559        mutex_unlock(&sel_mutex);
 560        vfree(data);
 561        return length;
 562}
 563
 564static const struct file_operations sel_load_ops = {
 565        .write          = sel_write_load,
 566        .llseek         = generic_file_llseek,
 567};
 568
 569static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 570{
 571        char *canon = NULL;
 572        u32 sid, len;
 573        ssize_t length;
 574
 575        length = task_has_security(current, SECURITY__CHECK_CONTEXT);
 576        if (length)
 577                goto out;
 578
 579        length = security_context_to_sid(buf, size, &sid, GFP_KERNEL);
 580        if (length)
 581                goto out;
 582
 583        length = security_sid_to_context(sid, &canon, &len);
 584        if (length)
 585                goto out;
 586
 587        length = -ERANGE;
 588        if (len > SIMPLE_TRANSACTION_LIMIT) {
 589                printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 590                        "payload max\n", __func__, len);
 591                goto out;
 592        }
 593
 594        memcpy(buf, canon, len);
 595        length = len;
 596out:
 597        kfree(canon);
 598        return length;
 599}
 600
 601static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 602                                     size_t count, loff_t *ppos)
 603{
 604        char tmpbuf[TMPBUFLEN];
 605        ssize_t length;
 606
 607        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
 608        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 609}
 610
 611static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 612                                      size_t count, loff_t *ppos)
 613{
 614        char *page = NULL;
 615        ssize_t length;
 616        unsigned int new_value;
 617
 618        length = task_has_security(current, SECURITY__SETCHECKREQPROT);
 619        if (length)
 620                goto out;
 621
 622        length = -ENOMEM;
 623        if (count >= PAGE_SIZE)
 624                goto out;
 625
 626        /* No partial writes. */
 627        length = -EINVAL;
 628        if (*ppos != 0)
 629                goto out;
 630
 631        length = -ENOMEM;
 632        page = (char *)get_zeroed_page(GFP_KERNEL);
 633        if (!page)
 634                goto out;
 635
 636        length = -EFAULT;
 637        if (copy_from_user(page, buf, count))
 638                goto out;
 639
 640        length = -EINVAL;
 641        if (sscanf(page, "%u", &new_value) != 1)
 642                goto out;
 643
 644        selinux_checkreqprot = new_value ? 1 : 0;
 645        length = count;
 646out:
 647        free_page((unsigned long) page);
 648        return length;
 649}
 650static const struct file_operations sel_checkreqprot_ops = {
 651        .read           = sel_read_checkreqprot,
 652        .write          = sel_write_checkreqprot,
 653        .llseek         = generic_file_llseek,
 654};
 655
 656/*
 657 * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
 658 */
 659static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
 660static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
 661static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
 662static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
 663static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
 664
 665static ssize_t (*write_op[])(struct file *, char *, size_t) = {
 666        [SEL_ACCESS] = sel_write_access,
 667        [SEL_CREATE] = sel_write_create,
 668        [SEL_RELABEL] = sel_write_relabel,
 669        [SEL_USER] = sel_write_user,
 670        [SEL_MEMBER] = sel_write_member,
 671        [SEL_CONTEXT] = sel_write_context,
 672};
 673
 674static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
 675{
 676        ino_t ino = file_inode(file)->i_ino;
 677        char *data;
 678        ssize_t rv;
 679
 680        if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
 681                return -EINVAL;
 682
 683        data = simple_transaction_get(file, buf, size);
 684        if (IS_ERR(data))
 685                return PTR_ERR(data);
 686
 687        rv = write_op[ino](file, data, size);
 688        if (rv > 0) {
 689                simple_transaction_set(file, rv);
 690                rv = size;
 691        }
 692        return rv;
 693}
 694
 695static const struct file_operations transaction_ops = {
 696        .write          = selinux_transaction_write,
 697        .read           = simple_transaction_read,
 698        .release        = simple_transaction_release,
 699        .llseek         = generic_file_llseek,
 700};
 701
 702/*
 703 * payload - write methods
 704 * If the method has a response, the response should be put in buf,
 705 * and the length returned.  Otherwise return 0 or and -error.
 706 */
 707
 708static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 709{
 710        char *scon = NULL, *tcon = NULL;
 711        u32 ssid, tsid;
 712        u16 tclass;
 713        struct av_decision avd;
 714        ssize_t length;
 715
 716        length = task_has_security(current, SECURITY__COMPUTE_AV);
 717        if (length)
 718                goto out;
 719
 720        length = -ENOMEM;
 721        scon = kzalloc(size + 1, GFP_KERNEL);
 722        if (!scon)
 723                goto out;
 724
 725        length = -ENOMEM;
 726        tcon = kzalloc(size + 1, GFP_KERNEL);
 727        if (!tcon)
 728                goto out;
 729
 730        length = -EINVAL;
 731        if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 732                goto out;
 733
 734        length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 735        if (length)
 736                goto out;
 737
 738        length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 739        if (length)
 740                goto out;
 741
 742        security_compute_av_user(ssid, tsid, tclass, &avd);
 743
 744        length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
 745                          "%x %x %x %x %u %x",
 746                          avd.allowed, 0xffffffff,
 747                          avd.auditallow, avd.auditdeny,
 748                          avd.seqno, avd.flags);
 749out:
 750        kfree(tcon);
 751        kfree(scon);
 752        return length;
 753}
 754
 755static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 756{
 757        char *scon = NULL, *tcon = NULL;
 758        char *namebuf = NULL, *objname = NULL;
 759        u32 ssid, tsid, newsid;
 760        u16 tclass;
 761        ssize_t length;
 762        char *newcon = NULL;
 763        u32 len;
 764        int nargs;
 765
 766        length = task_has_security(current, SECURITY__COMPUTE_CREATE);
 767        if (length)
 768                goto out;
 769
 770        length = -ENOMEM;
 771        scon = kzalloc(size + 1, GFP_KERNEL);
 772        if (!scon)
 773                goto out;
 774
 775        length = -ENOMEM;
 776        tcon = kzalloc(size + 1, GFP_KERNEL);
 777        if (!tcon)
 778                goto out;
 779
 780        length = -ENOMEM;
 781        namebuf = kzalloc(size + 1, GFP_KERNEL);
 782        if (!namebuf)
 783                goto out;
 784
 785        length = -EINVAL;
 786        nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
 787        if (nargs < 3 || nargs > 4)
 788                goto out;
 789        if (nargs == 4) {
 790                /*
 791                 * If and when the name of new object to be queried contains
 792                 * either whitespace or multibyte characters, they shall be
 793                 * encoded based on the percentage-encoding rule.
 794                 * If not encoded, the sscanf logic picks up only left-half
 795                 * of the supplied name; splitted by a whitespace unexpectedly.
 796                 */
 797                char   *r, *w;
 798                int     c1, c2;
 799
 800                r = w = namebuf;
 801                do {
 802                        c1 = *r++;
 803                        if (c1 == '+')
 804                                c1 = ' ';
 805                        else if (c1 == '%') {
 806                                c1 = hex_to_bin(*r++);
 807                                if (c1 < 0)
 808                                        goto out;
 809                                c2 = hex_to_bin(*r++);
 810                                if (c2 < 0)
 811                                        goto out;
 812                                c1 = (c1 << 4) | c2;
 813                        }
 814                        *w++ = c1;
 815                } while (c1 != '\0');
 816
 817                objname = namebuf;
 818        }
 819
 820        length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 821        if (length)
 822                goto out;
 823
 824        length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 825        if (length)
 826                goto out;
 827
 828        length = security_transition_sid_user(ssid, tsid, tclass,
 829                                              objname, &newsid);
 830        if (length)
 831                goto out;
 832
 833        length = security_sid_to_context(newsid, &newcon, &len);
 834        if (length)
 835                goto out;
 836
 837        length = -ERANGE;
 838        if (len > SIMPLE_TRANSACTION_LIMIT) {
 839                printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
 840                        "payload max\n", __func__, len);
 841                goto out;
 842        }
 843
 844        memcpy(buf, newcon, len);
 845        length = len;
 846out:
 847        kfree(newcon);
 848        kfree(namebuf);
 849        kfree(tcon);
 850        kfree(scon);
 851        return length;
 852}
 853
 854static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 855{
 856        char *scon = NULL, *tcon = NULL;
 857        u32 ssid, tsid, newsid;
 858        u16 tclass;
 859        ssize_t length;
 860        char *newcon = NULL;
 861        u32 len;
 862
 863        length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
 864        if (length)
 865                goto out;
 866
 867        length = -ENOMEM;
 868        scon = kzalloc(size + 1, GFP_KERNEL);
 869        if (!scon)
 870                goto out;
 871
 872        length = -ENOMEM;
 873        tcon = kzalloc(size + 1, GFP_KERNEL);
 874        if (!tcon)
 875                goto out;
 876
 877        length = -EINVAL;
 878        if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 879                goto out;
 880
 881        length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 882        if (length)
 883                goto out;
 884
 885        length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
 886        if (length)
 887                goto out;
 888
 889        length = security_change_sid(ssid, tsid, tclass, &newsid);
 890        if (length)
 891                goto out;
 892
 893        length = security_sid_to_context(newsid, &newcon, &len);
 894        if (length)
 895                goto out;
 896
 897        length = -ERANGE;
 898        if (len > SIMPLE_TRANSACTION_LIMIT)
 899                goto out;
 900
 901        memcpy(buf, newcon, len);
 902        length = len;
 903out:
 904        kfree(newcon);
 905        kfree(tcon);
 906        kfree(scon);
 907        return length;
 908}
 909
 910static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 911{
 912        char *con = NULL, *user = NULL, *ptr;
 913        u32 sid, *sids = NULL;
 914        ssize_t length;
 915        char *newcon;
 916        int i, rc;
 917        u32 len, nsids;
 918
 919        length = task_has_security(current, SECURITY__COMPUTE_USER);
 920        if (length)
 921                goto out;
 922
 923        length = -ENOMEM;
 924        con = kzalloc(size + 1, GFP_KERNEL);
 925        if (!con)
 926                goto out;
 927
 928        length = -ENOMEM;
 929        user = kzalloc(size + 1, GFP_KERNEL);
 930        if (!user)
 931                goto out;
 932
 933        length = -EINVAL;
 934        if (sscanf(buf, "%s %s", con, user) != 2)
 935                goto out;
 936
 937        length = security_context_str_to_sid(con, &sid, GFP_KERNEL);
 938        if (length)
 939                goto out;
 940
 941        length = security_get_user_sids(sid, user, &sids, &nsids);
 942        if (length)
 943                goto out;
 944
 945        length = sprintf(buf, "%u", nsids) + 1;
 946        ptr = buf + length;
 947        for (i = 0; i < nsids; i++) {
 948                rc = security_sid_to_context(sids[i], &newcon, &len);
 949                if (rc) {
 950                        length = rc;
 951                        goto out;
 952                }
 953                if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
 954                        kfree(newcon);
 955                        length = -ERANGE;
 956                        goto out;
 957                }
 958                memcpy(ptr, newcon, len);
 959                kfree(newcon);
 960                ptr += len;
 961                length += len;
 962        }
 963out:
 964        kfree(sids);
 965        kfree(user);
 966        kfree(con);
 967        return length;
 968}
 969
 970static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 971{
 972        char *scon = NULL, *tcon = NULL;
 973        u32 ssid, tsid, newsid;
 974        u16 tclass;
 975        ssize_t length;
 976        char *newcon = NULL;
 977        u32 len;
 978
 979        length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
 980        if (length)
 981                goto out;
 982
 983        length = -ENOMEM;
 984        scon = kzalloc(size + 1, GFP_KERNEL);
 985        if (!scon)
 986                goto out;
 987
 988        length = -ENOMEM;
 989        tcon = kzalloc(size + 1, GFP_KERNEL);
 990        if (!tcon)
 991                goto out;
 992
 993        length = -EINVAL;
 994        if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 995                goto out;
 996
 997        length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
 998        if (length)
 999                goto out;
1000
1001        length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
1002        if (length)
1003                goto out;
1004
1005        length = security_member_sid(ssid, tsid, tclass, &newsid);
1006        if (length)
1007                goto out;
1008
1009        length = security_sid_to_context(newsid, &newcon, &len);
1010        if (length)
1011                goto out;
1012
1013        length = -ERANGE;
1014        if (len > SIMPLE_TRANSACTION_LIMIT) {
1015                printk(KERN_ERR "SELinux: %s:  context size (%u) exceeds "
1016                        "payload max\n", __func__, len);
1017                goto out;
1018        }
1019
1020        memcpy(buf, newcon, len);
1021        length = len;
1022out:
1023        kfree(newcon);
1024        kfree(tcon);
1025        kfree(scon);
1026        return length;
1027}
1028
1029static struct inode *sel_make_inode(struct super_block *sb, int mode)
1030{
1031        struct inode *ret = new_inode(sb);
1032
1033        if (ret) {
1034                ret->i_mode = mode;
1035                ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1036        }
1037        return ret;
1038}
1039
1040static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1041                             size_t count, loff_t *ppos)
1042{
1043        char *page = NULL;
1044        ssize_t length;
1045        ssize_t ret;
1046        int cur_enforcing;
1047        unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1048        const char *name = filep->f_path.dentry->d_name.name;
1049
1050        mutex_lock(&sel_mutex);
1051
1052        ret = -EINVAL;
1053        if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1054                goto out;
1055
1056        ret = -ENOMEM;
1057        page = (char *)get_zeroed_page(GFP_KERNEL);
1058        if (!page)
1059                goto out;
1060
1061        cur_enforcing = security_get_bool_value(index);
1062        if (cur_enforcing < 0) {
1063                ret = cur_enforcing;
1064                goto out;
1065        }
1066        length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1067                          bool_pending_values[index]);
1068        ret = simple_read_from_buffer(buf, count, ppos, page, length);
1069out:
1070        mutex_unlock(&sel_mutex);
1071        free_page((unsigned long)page);
1072        return ret;
1073}
1074
1075static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1076                              size_t count, loff_t *ppos)
1077{
1078        char *page = NULL;
1079        ssize_t length;
1080        int new_value;
1081        unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1082        const char *name = filep->f_path.dentry->d_name.name;
1083
1084        mutex_lock(&sel_mutex);
1085
1086        length = task_has_security(current, SECURITY__SETBOOL);
1087        if (length)
1088                goto out;
1089
1090        length = -EINVAL;
1091        if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1092                goto out;
1093
1094        length = -ENOMEM;
1095        if (count >= PAGE_SIZE)
1096                goto out;
1097
1098        /* No partial writes. */
1099        length = -EINVAL;
1100        if (*ppos != 0)
1101                goto out;
1102
1103        length = -ENOMEM;
1104        page = (char *)get_zeroed_page(GFP_KERNEL);
1105        if (!page)
1106                goto out;
1107
1108        length = -EFAULT;
1109        if (copy_from_user(page, buf, count))
1110                goto out;
1111
1112        length = -EINVAL;
1113        if (sscanf(page, "%d", &new_value) != 1)
1114                goto out;
1115
1116        if (new_value)
1117                new_value = 1;
1118
1119        bool_pending_values[index] = new_value;
1120        length = count;
1121
1122out:
1123        mutex_unlock(&sel_mutex);
1124        free_page((unsigned long) page);
1125        return length;
1126}
1127
1128static const struct file_operations sel_bool_ops = {
1129        .read           = sel_read_bool,
1130        .write          = sel_write_bool,
1131        .llseek         = generic_file_llseek,
1132};
1133
1134static ssize_t sel_commit_bools_write(struct file *filep,
1135                                      const char __user *buf,
1136                                      size_t count, loff_t *ppos)
1137{
1138        char *page = NULL;
1139        ssize_t length;
1140        int new_value;
1141
1142        mutex_lock(&sel_mutex);
1143
1144        length = task_has_security(current, SECURITY__SETBOOL);
1145        if (length)
1146                goto out;
1147
1148        length = -ENOMEM;
1149        if (count >= PAGE_SIZE)
1150                goto out;
1151
1152        /* No partial writes. */
1153        length = -EINVAL;
1154        if (*ppos != 0)
1155                goto out;
1156
1157        length = -ENOMEM;
1158        page = (char *)get_zeroed_page(GFP_KERNEL);
1159        if (!page)
1160                goto out;
1161
1162        length = -EFAULT;
1163        if (copy_from_user(page, buf, count))
1164                goto out;
1165
1166        length = -EINVAL;
1167        if (sscanf(page, "%d", &new_value) != 1)
1168                goto out;
1169
1170        length = 0;
1171        if (new_value && bool_pending_values)
1172                length = security_set_bools(bool_num, bool_pending_values);
1173
1174        if (!length)
1175                length = count;
1176
1177out:
1178        mutex_unlock(&sel_mutex);
1179        free_page((unsigned long) page);
1180        return length;
1181}
1182
1183static const struct file_operations sel_commit_bools_ops = {
1184        .write          = sel_commit_bools_write,
1185        .llseek         = generic_file_llseek,
1186};
1187
1188static void sel_remove_entries(struct dentry *de)
1189{
1190        d_genocide(de);
1191        shrink_dcache_parent(de);
1192}
1193
1194#define BOOL_DIR_NAME "booleans"
1195
1196static int sel_make_bools(void)
1197{
1198        int i, ret;
1199        ssize_t len;
1200        struct dentry *dentry = NULL;
1201        struct dentry *dir = bool_dir;
1202        struct inode *inode = NULL;
1203        struct inode_security_struct *isec;
1204        char **names = NULL, *page;
1205        int num;
1206        int *values = NULL;
1207        u32 sid;
1208
1209        /* remove any existing files */
1210        for (i = 0; i < bool_num; i++)
1211                kfree(bool_pending_names[i]);
1212        kfree(bool_pending_names);
1213        kfree(bool_pending_values);
1214        bool_num = 0;
1215        bool_pending_names = NULL;
1216        bool_pending_values = NULL;
1217
1218        sel_remove_entries(dir);
1219
1220        ret = -ENOMEM;
1221        page = (char *)get_zeroed_page(GFP_KERNEL);
1222        if (!page)
1223                goto out;
1224
1225        ret = security_get_bools(&num, &names, &values);
1226        if (ret)
1227                goto out;
1228
1229        for (i = 0; i < num; i++) {
1230                ret = -ENOMEM;
1231                dentry = d_alloc_name(dir, names[i]);
1232                if (!dentry)
1233                        goto out;
1234
1235                ret = -ENOMEM;
1236                inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1237                if (!inode)
1238                        goto out;
1239
1240                ret = -ENAMETOOLONG;
1241                len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1242                if (len >= PAGE_SIZE)
1243                        goto out;
1244
1245                isec = (struct inode_security_struct *)inode->i_security;
1246                ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1247                if (ret)
1248                        goto out;
1249
1250                isec->sid = sid;
1251                isec->initialized = 1;
1252                inode->i_fop = &sel_bool_ops;
1253                inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1254                d_add(dentry, inode);
1255        }
1256        bool_num = num;
1257        bool_pending_names = names;
1258        bool_pending_values = values;
1259
1260        free_page((unsigned long)page);
1261        return 0;
1262out:
1263        free_page((unsigned long)page);
1264
1265        if (names) {
1266                for (i = 0; i < num; i++)
1267                        kfree(names[i]);
1268                kfree(names);
1269        }
1270        kfree(values);
1271        sel_remove_entries(dir);
1272
1273        return ret;
1274}
1275
1276#define NULL_FILE_NAME "null"
1277
1278struct path selinux_null;
1279
1280static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1281                                            size_t count, loff_t *ppos)
1282{
1283        char tmpbuf[TMPBUFLEN];
1284        ssize_t length;
1285
1286        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1287        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1288}
1289
1290static ssize_t sel_write_avc_cache_threshold(struct file *file,
1291                                             const char __user *buf,
1292                                             size_t count, loff_t *ppos)
1293
1294{
1295        char *page = NULL;
1296        ssize_t ret;
1297        int new_value;
1298
1299        ret = task_has_security(current, SECURITY__SETSECPARAM);
1300        if (ret)
1301                goto out;
1302
1303        ret = -ENOMEM;
1304        if (count >= PAGE_SIZE)
1305                goto out;
1306
1307        /* No partial writes. */
1308        ret = -EINVAL;
1309        if (*ppos != 0)
1310                goto out;
1311
1312        ret = -ENOMEM;
1313        page = (char *)get_zeroed_page(GFP_KERNEL);
1314        if (!page)
1315                goto out;
1316
1317        ret = -EFAULT;
1318        if (copy_from_user(page, buf, count))
1319                goto out;
1320
1321        ret = -EINVAL;
1322        if (sscanf(page, "%u", &new_value) != 1)
1323                goto out;
1324
1325        avc_cache_threshold = new_value;
1326
1327        ret = count;
1328out:
1329        free_page((unsigned long)page);
1330        return ret;
1331}
1332
1333static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1334                                       size_t count, loff_t *ppos)
1335{
1336        char *page;
1337        ssize_t length;
1338
1339        page = (char *)__get_free_page(GFP_KERNEL);
1340        if (!page)
1341                return -ENOMEM;
1342
1343        length = avc_get_hash_stats(page);
1344        if (length >= 0)
1345                length = simple_read_from_buffer(buf, count, ppos, page, length);
1346        free_page((unsigned long)page);
1347
1348        return length;
1349}
1350
1351static const struct file_operations sel_avc_cache_threshold_ops = {
1352        .read           = sel_read_avc_cache_threshold,
1353        .write          = sel_write_avc_cache_threshold,
1354        .llseek         = generic_file_llseek,
1355};
1356
1357static const struct file_operations sel_avc_hash_stats_ops = {
1358        .read           = sel_read_avc_hash_stats,
1359        .llseek         = generic_file_llseek,
1360};
1361
1362#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1363static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1364{
1365        int cpu;
1366
1367        for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1368                if (!cpu_possible(cpu))
1369                        continue;
1370                *idx = cpu + 1;
1371                return &per_cpu(avc_cache_stats, cpu);
1372        }
1373        return NULL;
1374}
1375
1376static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1377{
1378        loff_t n = *pos - 1;
1379
1380        if (*pos == 0)
1381                return SEQ_START_TOKEN;
1382
1383        return sel_avc_get_stat_idx(&n);
1384}
1385
1386static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1387{
1388        return sel_avc_get_stat_idx(pos);
1389}
1390
1391static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1392{
1393        struct avc_cache_stats *st = v;
1394
1395        if (v == SEQ_START_TOKEN)
1396                seq_printf(seq, "lookups hits misses allocations reclaims "
1397                           "frees\n");
1398        else {
1399                unsigned int lookups = st->lookups;
1400                unsigned int misses = st->misses;
1401                unsigned int hits = lookups - misses;
1402                seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1403                           hits, misses, st->allocations,
1404                           st->reclaims, st->frees);
1405        }
1406        return 0;
1407}
1408
1409static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1410{ }
1411
1412static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1413        .start          = sel_avc_stats_seq_start,
1414        .next           = sel_avc_stats_seq_next,
1415        .show           = sel_avc_stats_seq_show,
1416        .stop           = sel_avc_stats_seq_stop,
1417};
1418
1419static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1420{
1421        return seq_open(file, &sel_avc_cache_stats_seq_ops);
1422}
1423
1424static const struct file_operations sel_avc_cache_stats_ops = {
1425        .open           = sel_open_avc_cache_stats,
1426        .read           = seq_read,
1427        .llseek         = seq_lseek,
1428        .release        = seq_release,
1429};
1430#endif
1431
1432static int sel_make_avc_files(struct dentry *dir)
1433{
1434        int i;
1435        static struct tree_descr files[] = {
1436                { "cache_threshold",
1437                  &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1438                { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1439#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1440                { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1441#endif
1442        };
1443
1444        for (i = 0; i < ARRAY_SIZE(files); i++) {
1445                struct inode *inode;
1446                struct dentry *dentry;
1447
1448                dentry = d_alloc_name(dir, files[i].name);
1449                if (!dentry)
1450                        return -ENOMEM;
1451
1452                inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1453                if (!inode)
1454                        return -ENOMEM;
1455
1456                inode->i_fop = files[i].ops;
1457                inode->i_ino = ++sel_last_ino;
1458                d_add(dentry, inode);
1459        }
1460
1461        return 0;
1462}
1463
1464static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1465                                size_t count, loff_t *ppos)
1466{
1467        char *con;
1468        u32 sid, len;
1469        ssize_t ret;
1470
1471        sid = file_inode(file)->i_ino&SEL_INO_MASK;
1472        ret = security_sid_to_context(sid, &con, &len);
1473        if (ret)
1474                return ret;
1475
1476        ret = simple_read_from_buffer(buf, count, ppos, con, len);
1477        kfree(con);
1478        return ret;
1479}
1480
1481static const struct file_operations sel_initcon_ops = {
1482        .read           = sel_read_initcon,
1483        .llseek         = generic_file_llseek,
1484};
1485
1486static int sel_make_initcon_files(struct dentry *dir)
1487{
1488        int i;
1489
1490        for (i = 1; i <= SECINITSID_NUM; i++) {
1491                struct inode *inode;
1492                struct dentry *dentry;
1493                dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1494                if (!dentry)
1495                        return -ENOMEM;
1496
1497                inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1498                if (!inode)
1499                        return -ENOMEM;
1500
1501                inode->i_fop = &sel_initcon_ops;
1502                inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1503                d_add(dentry, inode);
1504        }
1505
1506        return 0;
1507}
1508
1509static inline unsigned long sel_class_to_ino(u16 class)
1510{
1511        return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1512}
1513
1514static inline u16 sel_ino_to_class(unsigned long ino)
1515{
1516        return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1517}
1518
1519static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1520{
1521        return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1522}
1523
1524static inline u32 sel_ino_to_perm(unsigned long ino)
1525{
1526        return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1527}
1528
1529static ssize_t sel_read_class(struct file *file, char __user *buf,
1530                                size_t count, loff_t *ppos)
1531{
1532        unsigned long ino = file_inode(file)->i_ino;
1533        char res[TMPBUFLEN];
1534        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1535        return simple_read_from_buffer(buf, count, ppos, res, len);
1536}
1537
1538static const struct file_operations sel_class_ops = {
1539        .read           = sel_read_class,
1540        .llseek         = generic_file_llseek,
1541};
1542
1543static ssize_t sel_read_perm(struct file *file, char __user *buf,
1544                                size_t count, loff_t *ppos)
1545{
1546        unsigned long ino = file_inode(file)->i_ino;
1547        char res[TMPBUFLEN];
1548        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1549        return simple_read_from_buffer(buf, count, ppos, res, len);
1550}
1551
1552static const struct file_operations sel_perm_ops = {
1553        .read           = sel_read_perm,
1554        .llseek         = generic_file_llseek,
1555};
1556
1557static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1558                                  size_t count, loff_t *ppos)
1559{
1560        int value;
1561        char tmpbuf[TMPBUFLEN];
1562        ssize_t length;
1563        unsigned long i_ino = file_inode(file)->i_ino;
1564
1565        value = security_policycap_supported(i_ino & SEL_INO_MASK);
1566        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1567
1568        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1569}
1570
1571static const struct file_operations sel_policycap_ops = {
1572        .read           = sel_read_policycap,
1573        .llseek         = generic_file_llseek,
1574};
1575
1576static int sel_make_perm_files(char *objclass, int classvalue,
1577                                struct dentry *dir)
1578{
1579        int i, rc, nperms;
1580        char **perms;
1581
1582        rc = security_get_permissions(objclass, &perms, &nperms);
1583        if (rc)
1584                return rc;
1585
1586        for (i = 0; i < nperms; i++) {
1587                struct inode *inode;
1588                struct dentry *dentry;
1589
1590                rc = -ENOMEM;
1591                dentry = d_alloc_name(dir, perms[i]);
1592                if (!dentry)
1593                        goto out;
1594
1595                rc = -ENOMEM;
1596                inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1597                if (!inode)
1598                        goto out;
1599
1600                inode->i_fop = &sel_perm_ops;
1601                /* i+1 since perm values are 1-indexed */
1602                inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1603                d_add(dentry, inode);
1604        }
1605        rc = 0;
1606out:
1607        for (i = 0; i < nperms; i++)
1608                kfree(perms[i]);
1609        kfree(perms);
1610        return rc;
1611}
1612
1613static int sel_make_class_dir_entries(char *classname, int index,
1614                                        struct dentry *dir)
1615{
1616        struct dentry *dentry = NULL;
1617        struct inode *inode = NULL;
1618        int rc;
1619
1620        dentry = d_alloc_name(dir, "index");
1621        if (!dentry)
1622                return -ENOMEM;
1623
1624        inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1625        if (!inode)
1626                return -ENOMEM;
1627
1628        inode->i_fop = &sel_class_ops;
1629        inode->i_ino = sel_class_to_ino(index);
1630        d_add(dentry, inode);
1631
1632        dentry = sel_make_dir(dir, "perms", &last_class_ino);
1633        if (IS_ERR(dentry))
1634                return PTR_ERR(dentry);
1635
1636        rc = sel_make_perm_files(classname, index, dentry);
1637
1638        return rc;
1639}
1640
1641static int sel_make_classes(void)
1642{
1643        int rc, nclasses, i;
1644        char **classes;
1645
1646        /* delete any existing entries */
1647        sel_remove_entries(class_dir);
1648
1649        rc = security_get_classes(&classes, &nclasses);
1650        if (rc)
1651                return rc;
1652
1653        /* +2 since classes are 1-indexed */
1654        last_class_ino = sel_class_to_ino(nclasses + 2);
1655
1656        for (i = 0; i < nclasses; i++) {
1657                struct dentry *class_name_dir;
1658
1659                class_name_dir = sel_make_dir(class_dir, classes[i],
1660                                &last_class_ino);
1661                if (IS_ERR(class_name_dir)) {
1662                        rc = PTR_ERR(class_name_dir);
1663                        goto out;
1664                }
1665
1666                /* i+1 since class values are 1-indexed */
1667                rc = sel_make_class_dir_entries(classes[i], i + 1,
1668                                class_name_dir);
1669                if (rc)
1670                        goto out;
1671        }
1672        rc = 0;
1673out:
1674        for (i = 0; i < nclasses; i++)
1675                kfree(classes[i]);
1676        kfree(classes);
1677        return rc;
1678}
1679
1680static int sel_make_policycap(void)
1681{
1682        unsigned int iter;
1683        struct dentry *dentry = NULL;
1684        struct inode *inode = NULL;
1685
1686        sel_remove_entries(policycap_dir);
1687
1688        for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1689                if (iter < ARRAY_SIZE(policycap_names))
1690                        dentry = d_alloc_name(policycap_dir,
1691                                              policycap_names[iter]);
1692                else
1693                        dentry = d_alloc_name(policycap_dir, "unknown");
1694
1695                if (dentry == NULL)
1696                        return -ENOMEM;
1697
1698                inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1699                if (inode == NULL)
1700                        return -ENOMEM;
1701
1702                inode->i_fop = &sel_policycap_ops;
1703                inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1704                d_add(dentry, inode);
1705        }
1706
1707        return 0;
1708}
1709
1710static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1711                        unsigned long *ino)
1712{
1713        struct dentry *dentry = d_alloc_name(dir, name);
1714        struct inode *inode;
1715
1716        if (!dentry)
1717                return ERR_PTR(-ENOMEM);
1718
1719        inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1720        if (!inode) {
1721                dput(dentry);
1722                return ERR_PTR(-ENOMEM);
1723        }
1724
1725        inode->i_op = &simple_dir_inode_operations;
1726        inode->i_fop = &simple_dir_operations;
1727        inode->i_ino = ++(*ino);
1728        /* directory inodes start off with i_nlink == 2 (for "." entry) */
1729        inc_nlink(inode);
1730        d_add(dentry, inode);
1731        /* bump link count on parent directory, too */
1732        inc_nlink(d_inode(dir));
1733
1734        return dentry;
1735}
1736
1737static int sel_fill_super(struct super_block *sb, void *data, int silent)
1738{
1739        int ret;
1740        struct dentry *dentry;
1741        struct inode *inode;
1742        struct inode_security_struct *isec;
1743
1744        static struct tree_descr selinux_files[] = {
1745                [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1746                [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1747                [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1748                [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1749                [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1750                [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1751                [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1752                [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1753                [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1754                [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1755                [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1756                [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1757                [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1758                [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1759                [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1760                [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1761                [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1762                /* last one */ {""}
1763        };
1764        ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1765        if (ret)
1766                goto err;
1767
1768        bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1769        if (IS_ERR(bool_dir)) {
1770                ret = PTR_ERR(bool_dir);
1771                bool_dir = NULL;
1772                goto err;
1773        }
1774
1775        ret = -ENOMEM;
1776        dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1777        if (!dentry)
1778                goto err;
1779
1780        ret = -ENOMEM;
1781        inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1782        if (!inode)
1783                goto err;
1784
1785        inode->i_ino = ++sel_last_ino;
1786        isec = (struct inode_security_struct *)inode->i_security;
1787        isec->sid = SECINITSID_DEVNULL;
1788        isec->sclass = SECCLASS_CHR_FILE;
1789        isec->initialized = 1;
1790
1791        init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1792        d_add(dentry, inode);
1793        selinux_null.dentry = dentry;
1794
1795        dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1796        if (IS_ERR(dentry)) {
1797                ret = PTR_ERR(dentry);
1798                goto err;
1799        }
1800
1801        ret = sel_make_avc_files(dentry);
1802        if (ret)
1803                goto err;
1804
1805        dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1806        if (IS_ERR(dentry)) {
1807                ret = PTR_ERR(dentry);
1808                goto err;
1809        }
1810
1811        ret = sel_make_initcon_files(dentry);
1812        if (ret)
1813                goto err;
1814
1815        class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1816        if (IS_ERR(class_dir)) {
1817                ret = PTR_ERR(class_dir);
1818                class_dir = NULL;
1819                goto err;
1820        }
1821
1822        policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1823        if (IS_ERR(policycap_dir)) {
1824                ret = PTR_ERR(policycap_dir);
1825                policycap_dir = NULL;
1826                goto err;
1827        }
1828        return 0;
1829err:
1830        printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1831                __func__);
1832        return ret;
1833}
1834
1835static struct dentry *sel_mount(struct file_system_type *fs_type,
1836                      int flags, const char *dev_name, void *data)
1837{
1838        return mount_single(fs_type, flags, data, sel_fill_super);
1839}
1840
1841static struct file_system_type sel_fs_type = {
1842        .name           = "selinuxfs",
1843        .mount          = sel_mount,
1844        .kill_sb        = kill_litter_super,
1845};
1846
1847struct vfsmount *selinuxfs_mount;
1848
1849static int __init init_sel_fs(void)
1850{
1851        int err;
1852
1853        if (!selinux_enabled)
1854                return 0;
1855
1856        err = sysfs_create_mount_point(fs_kobj, "selinux");
1857        if (err)
1858                return err;
1859
1860        err = register_filesystem(&sel_fs_type);
1861        if (err) {
1862                sysfs_remove_mount_point(fs_kobj, "selinux");
1863                return err;
1864        }
1865
1866        selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1867        if (IS_ERR(selinuxfs_mount)) {
1868                printk(KERN_ERR "selinuxfs:  could not mount!\n");
1869                err = PTR_ERR(selinuxfs_mount);
1870                selinuxfs_mount = NULL;
1871        }
1872
1873        return err;
1874}
1875
1876__initcall(init_sel_fs);
1877
1878#ifdef CONFIG_SECURITY_SELINUX_DISABLE
1879void exit_sel_fs(void)
1880{
1881        sysfs_remove_mount_point(fs_kobj, "selinux");
1882        kern_unmount(selinuxfs_mount);
1883        unregister_filesystem(&sel_fs_type);
1884}
1885#endif
1886