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                        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 = filp->f_path.dentry->d_inode->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                        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_RESERVED;
 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                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->f_path.dentry->d_inode->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        struct inode *inode = filep->f_path.dentry->d_inode;
1046        unsigned index = inode->i_ino & SEL_INO_MASK;
1047        const char *name = filep->f_path.dentry->d_name.name;
1048
1049        mutex_lock(&sel_mutex);
1050
1051        ret = -EINVAL;
1052        if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1053                goto out;
1054
1055        ret = -ENOMEM;
1056        page = (char *)get_zeroed_page(GFP_KERNEL);
1057        if (!page)
1058                goto out;
1059
1060        cur_enforcing = security_get_bool_value(index);
1061        if (cur_enforcing < 0) {
1062                ret = cur_enforcing;
1063                goto out;
1064        }
1065        length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1066                          bool_pending_values[index]);
1067        ret = simple_read_from_buffer(buf, count, ppos, page, length);
1068out:
1069        mutex_unlock(&sel_mutex);
1070        free_page((unsigned long)page);
1071        return ret;
1072}
1073
1074static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1075                              size_t count, loff_t *ppos)
1076{
1077        char *page = NULL;
1078        ssize_t length;
1079        int new_value;
1080        struct inode *inode = filep->f_path.dentry->d_inode;
1081        unsigned index = inode->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        struct list_head *node;
1191
1192        spin_lock(&de->d_lock);
1193        node = de->d_subdirs.next;
1194        while (node != &de->d_subdirs) {
1195                struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1196
1197                spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1198                list_del_init(node);
1199
1200                if (d->d_inode) {
1201                        dget_dlock(d);
1202                        spin_unlock(&de->d_lock);
1203                        spin_unlock(&d->d_lock);
1204                        d_delete(d);
1205                        simple_unlink(de->d_inode, d);
1206                        dput(d);
1207                        spin_lock(&de->d_lock);
1208                } else
1209                        spin_unlock(&d->d_lock);
1210                node = de->d_subdirs.next;
1211        }
1212
1213        spin_unlock(&de->d_lock);
1214}
1215
1216#define BOOL_DIR_NAME "booleans"
1217
1218static int sel_make_bools(void)
1219{
1220        int i, ret;
1221        ssize_t len;
1222        struct dentry *dentry = NULL;
1223        struct dentry *dir = bool_dir;
1224        struct inode *inode = NULL;
1225        struct inode_security_struct *isec;
1226        char **names = NULL, *page;
1227        int num;
1228        int *values = NULL;
1229        u32 sid;
1230
1231        /* remove any existing files */
1232        for (i = 0; i < bool_num; i++)
1233                kfree(bool_pending_names[i]);
1234        kfree(bool_pending_names);
1235        kfree(bool_pending_values);
1236        bool_num = 0;
1237        bool_pending_names = NULL;
1238        bool_pending_values = NULL;
1239
1240        sel_remove_entries(dir);
1241
1242        ret = -ENOMEM;
1243        page = (char *)get_zeroed_page(GFP_KERNEL);
1244        if (!page)
1245                goto out;
1246
1247        ret = security_get_bools(&num, &names, &values);
1248        if (ret)
1249                goto out;
1250
1251        for (i = 0; i < num; i++) {
1252                ret = -ENOMEM;
1253                dentry = d_alloc_name(dir, names[i]);
1254                if (!dentry)
1255                        goto out;
1256
1257                ret = -ENOMEM;
1258                inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1259                if (!inode)
1260                        goto out;
1261
1262                ret = -ENAMETOOLONG;
1263                len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1264                if (len >= PAGE_SIZE)
1265                        goto out;
1266
1267                isec = (struct inode_security_struct *)inode->i_security;
1268                ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1269                if (ret)
1270                        goto out;
1271
1272                isec->sid = sid;
1273                isec->initialized = 1;
1274                inode->i_fop = &sel_bool_ops;
1275                inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1276                d_add(dentry, inode);
1277        }
1278        bool_num = num;
1279        bool_pending_names = names;
1280        bool_pending_values = values;
1281
1282        free_page((unsigned long)page);
1283        return 0;
1284out:
1285        free_page((unsigned long)page);
1286
1287        if (names) {
1288                for (i = 0; i < num; i++)
1289                        kfree(names[i]);
1290                kfree(names);
1291        }
1292        kfree(values);
1293        sel_remove_entries(dir);
1294
1295        return ret;
1296}
1297
1298#define NULL_FILE_NAME "null"
1299
1300struct path selinux_null;
1301
1302static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1303                                            size_t count, loff_t *ppos)
1304{
1305        char tmpbuf[TMPBUFLEN];
1306        ssize_t length;
1307
1308        length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1309        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1310}
1311
1312static ssize_t sel_write_avc_cache_threshold(struct file *file,
1313                                             const char __user *buf,
1314                                             size_t count, loff_t *ppos)
1315
1316{
1317        char *page = NULL;
1318        ssize_t ret;
1319        int new_value;
1320
1321        ret = task_has_security(current, SECURITY__SETSECPARAM);
1322        if (ret)
1323                goto out;
1324
1325        ret = -ENOMEM;
1326        if (count >= PAGE_SIZE)
1327                goto out;
1328
1329        /* No partial writes. */
1330        ret = -EINVAL;
1331        if (*ppos != 0)
1332                goto out;
1333
1334        ret = -ENOMEM;
1335        page = (char *)get_zeroed_page(GFP_KERNEL);
1336        if (!page)
1337                goto out;
1338
1339        ret = -EFAULT;
1340        if (copy_from_user(page, buf, count))
1341                goto out;
1342
1343        ret = -EINVAL;
1344        if (sscanf(page, "%u", &new_value) != 1)
1345                goto out;
1346
1347        avc_cache_threshold = new_value;
1348
1349        ret = count;
1350out:
1351        free_page((unsigned long)page);
1352        return ret;
1353}
1354
1355static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1356                                       size_t count, loff_t *ppos)
1357{
1358        char *page;
1359        ssize_t length;
1360
1361        page = (char *)__get_free_page(GFP_KERNEL);
1362        if (!page)
1363                return -ENOMEM;
1364
1365        length = avc_get_hash_stats(page);
1366        if (length >= 0)
1367                length = simple_read_from_buffer(buf, count, ppos, page, length);
1368        free_page((unsigned long)page);
1369
1370        return length;
1371}
1372
1373static const struct file_operations sel_avc_cache_threshold_ops = {
1374        .read           = sel_read_avc_cache_threshold,
1375        .write          = sel_write_avc_cache_threshold,
1376        .llseek         = generic_file_llseek,
1377};
1378
1379static const struct file_operations sel_avc_hash_stats_ops = {
1380        .read           = sel_read_avc_hash_stats,
1381        .llseek         = generic_file_llseek,
1382};
1383
1384#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1385static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1386{
1387        int cpu;
1388
1389        for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1390                if (!cpu_possible(cpu))
1391                        continue;
1392                *idx = cpu + 1;
1393                return &per_cpu(avc_cache_stats, cpu);
1394        }
1395        return NULL;
1396}
1397
1398static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1399{
1400        loff_t n = *pos - 1;
1401
1402        if (*pos == 0)
1403                return SEQ_START_TOKEN;
1404
1405        return sel_avc_get_stat_idx(&n);
1406}
1407
1408static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1409{
1410        return sel_avc_get_stat_idx(pos);
1411}
1412
1413static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1414{
1415        struct avc_cache_stats *st = v;
1416
1417        if (v == SEQ_START_TOKEN)
1418                seq_printf(seq, "lookups hits misses allocations reclaims "
1419                           "frees\n");
1420        else {
1421                unsigned int lookups = st->lookups;
1422                unsigned int misses = st->misses;
1423                unsigned int hits = lookups - misses;
1424                seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1425                           hits, misses, st->allocations,
1426                           st->reclaims, st->frees);
1427        }
1428        return 0;
1429}
1430
1431static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1432{ }
1433
1434static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1435        .start          = sel_avc_stats_seq_start,
1436        .next           = sel_avc_stats_seq_next,
1437        .show           = sel_avc_stats_seq_show,
1438        .stop           = sel_avc_stats_seq_stop,
1439};
1440
1441static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1442{
1443        return seq_open(file, &sel_avc_cache_stats_seq_ops);
1444}
1445
1446static const struct file_operations sel_avc_cache_stats_ops = {
1447        .open           = sel_open_avc_cache_stats,
1448        .read           = seq_read,
1449        .llseek         = seq_lseek,
1450        .release        = seq_release,
1451};
1452#endif
1453
1454static int sel_make_avc_files(struct dentry *dir)
1455{
1456        int i;
1457        static struct tree_descr files[] = {
1458                { "cache_threshold",
1459                  &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1460                { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1461#ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1462                { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1463#endif
1464        };
1465
1466        for (i = 0; i < ARRAY_SIZE(files); i++) {
1467                struct inode *inode;
1468                struct dentry *dentry;
1469
1470                dentry = d_alloc_name(dir, files[i].name);
1471                if (!dentry)
1472                        return -ENOMEM;
1473
1474                inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1475                if (!inode)
1476                        return -ENOMEM;
1477
1478                inode->i_fop = files[i].ops;
1479                inode->i_ino = ++sel_last_ino;
1480                d_add(dentry, inode);
1481        }
1482
1483        return 0;
1484}
1485
1486static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1487                                size_t count, loff_t *ppos)
1488{
1489        struct inode *inode;
1490        char *con;
1491        u32 sid, len;
1492        ssize_t ret;
1493
1494        inode = file->f_path.dentry->d_inode;
1495        sid = inode->i_ino&SEL_INO_MASK;
1496        ret = security_sid_to_context(sid, &con, &len);
1497        if (ret)
1498                return ret;
1499
1500        ret = simple_read_from_buffer(buf, count, ppos, con, len);
1501        kfree(con);
1502        return ret;
1503}
1504
1505static const struct file_operations sel_initcon_ops = {
1506        .read           = sel_read_initcon,
1507        .llseek         = generic_file_llseek,
1508};
1509
1510static int sel_make_initcon_files(struct dentry *dir)
1511{
1512        int i;
1513
1514        for (i = 1; i <= SECINITSID_NUM; i++) {
1515                struct inode *inode;
1516                struct dentry *dentry;
1517                dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1518                if (!dentry)
1519                        return -ENOMEM;
1520
1521                inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1522                if (!inode)
1523                        return -ENOMEM;
1524
1525                inode->i_fop = &sel_initcon_ops;
1526                inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1527                d_add(dentry, inode);
1528        }
1529
1530        return 0;
1531}
1532
1533static inline unsigned long sel_class_to_ino(u16 class)
1534{
1535        return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1536}
1537
1538static inline u16 sel_ino_to_class(unsigned long ino)
1539{
1540        return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1541}
1542
1543static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1544{
1545        return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1546}
1547
1548static inline u32 sel_ino_to_perm(unsigned long ino)
1549{
1550        return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1551}
1552
1553static ssize_t sel_read_class(struct file *file, char __user *buf,
1554                                size_t count, loff_t *ppos)
1555{
1556        unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1557        char res[TMPBUFLEN];
1558        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1559        return simple_read_from_buffer(buf, count, ppos, res, len);
1560}
1561
1562static const struct file_operations sel_class_ops = {
1563        .read           = sel_read_class,
1564        .llseek         = generic_file_llseek,
1565};
1566
1567static ssize_t sel_read_perm(struct file *file, char __user *buf,
1568                                size_t count, loff_t *ppos)
1569{
1570        unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1571        char res[TMPBUFLEN];
1572        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1573        return simple_read_from_buffer(buf, count, ppos, res, len);
1574}
1575
1576static const struct file_operations sel_perm_ops = {
1577        .read           = sel_read_perm,
1578        .llseek         = generic_file_llseek,
1579};
1580
1581static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1582                                  size_t count, loff_t *ppos)
1583{
1584        int value;
1585        char tmpbuf[TMPBUFLEN];
1586        ssize_t length;
1587        unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1588
1589        value = security_policycap_supported(i_ino & SEL_INO_MASK);
1590        length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1591
1592        return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1593}
1594
1595static const struct file_operations sel_policycap_ops = {
1596        .read           = sel_read_policycap,
1597        .llseek         = generic_file_llseek,
1598};
1599
1600static int sel_make_perm_files(char *objclass, int classvalue,
1601                                struct dentry *dir)
1602{
1603        int i, rc, nperms;
1604        char **perms;
1605
1606        rc = security_get_permissions(objclass, &perms, &nperms);
1607        if (rc)
1608                return rc;
1609
1610        for (i = 0; i < nperms; i++) {
1611                struct inode *inode;
1612                struct dentry *dentry;
1613
1614                rc = -ENOMEM;
1615                dentry = d_alloc_name(dir, perms[i]);
1616                if (!dentry)
1617                        goto out;
1618
1619                rc = -ENOMEM;
1620                inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1621                if (!inode)
1622                        goto out;
1623
1624                inode->i_fop = &sel_perm_ops;
1625                /* i+1 since perm values are 1-indexed */
1626                inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1627                d_add(dentry, inode);
1628        }
1629        rc = 0;
1630out:
1631        for (i = 0; i < nperms; i++)
1632                kfree(perms[i]);
1633        kfree(perms);
1634        return rc;
1635}
1636
1637static int sel_make_class_dir_entries(char *classname, int index,
1638                                        struct dentry *dir)
1639{
1640        struct dentry *dentry = NULL;
1641        struct inode *inode = NULL;
1642        int rc;
1643
1644        dentry = d_alloc_name(dir, "index");
1645        if (!dentry)
1646                return -ENOMEM;
1647
1648        inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1649        if (!inode)
1650                return -ENOMEM;
1651
1652        inode->i_fop = &sel_class_ops;
1653        inode->i_ino = sel_class_to_ino(index);
1654        d_add(dentry, inode);
1655
1656        dentry = sel_make_dir(dir, "perms", &last_class_ino);
1657        if (IS_ERR(dentry))
1658                return PTR_ERR(dentry);
1659
1660        rc = sel_make_perm_files(classname, index, dentry);
1661
1662        return rc;
1663}
1664
1665static void sel_remove_classes(void)
1666{
1667        struct list_head *class_node;
1668
1669        list_for_each(class_node, &class_dir->d_subdirs) {
1670                struct dentry *class_subdir = list_entry(class_node,
1671                                        struct dentry, d_u.d_child);
1672                struct list_head *class_subdir_node;
1673
1674                list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1675                        struct dentry *d = list_entry(class_subdir_node,
1676                                                struct dentry, d_u.d_child);
1677
1678                        if (d->d_inode)
1679                                if (d->d_inode->i_mode & S_IFDIR)
1680                                        sel_remove_entries(d);
1681                }
1682
1683                sel_remove_entries(class_subdir);
1684        }
1685
1686        sel_remove_entries(class_dir);
1687}
1688
1689static int sel_make_classes(void)
1690{
1691        int rc, nclasses, i;
1692        char **classes;
1693
1694        /* delete any existing entries */
1695        sel_remove_classes();
1696
1697        rc = security_get_classes(&classes, &nclasses);
1698        if (rc)
1699                return rc;
1700
1701        /* +2 since classes are 1-indexed */
1702        last_class_ino = sel_class_to_ino(nclasses + 2);
1703
1704        for (i = 0; i < nclasses; i++) {
1705                struct dentry *class_name_dir;
1706
1707                class_name_dir = sel_make_dir(class_dir, classes[i],
1708                                &last_class_ino);
1709                if (IS_ERR(class_name_dir)) {
1710                        rc = PTR_ERR(class_name_dir);
1711                        goto out;
1712                }
1713
1714                /* i+1 since class values are 1-indexed */
1715                rc = sel_make_class_dir_entries(classes[i], i + 1,
1716                                class_name_dir);
1717                if (rc)
1718                        goto out;
1719        }
1720        rc = 0;
1721out:
1722        for (i = 0; i < nclasses; i++)
1723                kfree(classes[i]);
1724        kfree(classes);
1725        return rc;
1726}
1727
1728static int sel_make_policycap(void)
1729{
1730        unsigned int iter;
1731        struct dentry *dentry = NULL;
1732        struct inode *inode = NULL;
1733
1734        sel_remove_entries(policycap_dir);
1735
1736        for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1737                if (iter < ARRAY_SIZE(policycap_names))
1738                        dentry = d_alloc_name(policycap_dir,
1739                                              policycap_names[iter]);
1740                else
1741                        dentry = d_alloc_name(policycap_dir, "unknown");
1742
1743                if (dentry == NULL)
1744                        return -ENOMEM;
1745
1746                inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1747                if (inode == NULL)
1748                        return -ENOMEM;
1749
1750                inode->i_fop = &sel_policycap_ops;
1751                inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1752                d_add(dentry, inode);
1753        }
1754
1755        return 0;
1756}
1757
1758static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1759                        unsigned long *ino)
1760{
1761        struct dentry *dentry = d_alloc_name(dir, name);
1762        struct inode *inode;
1763
1764        if (!dentry)
1765                return ERR_PTR(-ENOMEM);
1766
1767        inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1768        if (!inode) {
1769                dput(dentry);
1770                return ERR_PTR(-ENOMEM);
1771        }
1772
1773        inode->i_op = &simple_dir_inode_operations;
1774        inode->i_fop = &simple_dir_operations;
1775        inode->i_ino = ++(*ino);
1776        /* directory inodes start off with i_nlink == 2 (for "." entry) */
1777        inc_nlink(inode);
1778        d_add(dentry, inode);
1779        /* bump link count on parent directory, too */
1780        inc_nlink(dir->d_inode);
1781
1782        return dentry;
1783}
1784
1785static int sel_fill_super(struct super_block *sb, void *data, int silent)
1786{
1787        int ret;
1788        struct dentry *dentry;
1789        struct inode *inode;
1790        struct inode_security_struct *isec;
1791
1792        static struct tree_descr selinux_files[] = {
1793                [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1794                [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1795                [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1796                [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1797                [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1798                [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1799                [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1800                [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1801                [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1802                [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1803                [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1804                [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1805                [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1806                [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1807                [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1808                [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1809                [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1810                /* last one */ {""}
1811        };
1812        ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1813        if (ret)
1814                goto err;
1815
1816        bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1817        if (IS_ERR(bool_dir)) {
1818                ret = PTR_ERR(bool_dir);
1819                bool_dir = NULL;
1820                goto err;
1821        }
1822
1823        ret = -ENOMEM;
1824        dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1825        if (!dentry)
1826                goto err;
1827
1828        ret = -ENOMEM;
1829        inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1830        if (!inode)
1831                goto err;
1832
1833        inode->i_ino = ++sel_last_ino;
1834        isec = (struct inode_security_struct *)inode->i_security;
1835        isec->sid = SECINITSID_DEVNULL;
1836        isec->sclass = SECCLASS_CHR_FILE;
1837        isec->initialized = 1;
1838
1839        init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1840        d_add(dentry, inode);
1841        selinux_null.dentry = dentry;
1842
1843        dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1844        if (IS_ERR(dentry)) {
1845                ret = PTR_ERR(dentry);
1846                goto err;
1847        }
1848
1849        ret = sel_make_avc_files(dentry);
1850        if (ret)
1851                goto err;
1852
1853        dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1854        if (IS_ERR(dentry)) {
1855                ret = PTR_ERR(dentry);
1856                goto err;
1857        }
1858
1859        ret = sel_make_initcon_files(dentry);
1860        if (ret)
1861                goto err;
1862
1863        class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1864        if (IS_ERR(class_dir)) {
1865                ret = PTR_ERR(class_dir);
1866                class_dir = NULL;
1867                goto err;
1868        }
1869
1870        policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1871        if (IS_ERR(policycap_dir)) {
1872                ret = PTR_ERR(policycap_dir);
1873                policycap_dir = NULL;
1874                goto err;
1875        }
1876        return 0;
1877err:
1878        printk(KERN_ERR "SELinux: %s:  failed while creating inodes\n",
1879                __func__);
1880        return ret;
1881}
1882
1883static struct dentry *sel_mount(struct file_system_type *fs_type,
1884                      int flags, const char *dev_name, void *data)
1885{
1886        return mount_single(fs_type, flags, data, sel_fill_super);
1887}
1888
1889static struct file_system_type sel_fs_type = {
1890        .name           = "selinuxfs",
1891        .mount          = sel_mount,
1892        .kill_sb        = kill_litter_super,
1893};
1894
1895struct vfsmount *selinuxfs_mount;
1896static struct kobject *selinuxfs_kobj;
1897
1898static int __init init_sel_fs(void)
1899{
1900        int err;
1901
1902        if (!selinux_enabled)
1903                return 0;
1904
1905        selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1906        if (!selinuxfs_kobj)
1907                return -ENOMEM;
1908
1909        err = register_filesystem(&sel_fs_type);
1910        if (err) {
1911                kobject_put(selinuxfs_kobj);
1912                return err;
1913        }
1914
1915        selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1916        if (IS_ERR(selinuxfs_mount)) {
1917                printk(KERN_ERR "selinuxfs:  could not mount!\n");
1918                err = PTR_ERR(selinuxfs_mount);
1919                selinuxfs_mount = NULL;
1920        }
1921
1922        return err;
1923}
1924
1925__initcall(init_sel_fs);
1926
1927#ifdef CONFIG_SECURITY_SELINUX_DISABLE
1928void exit_sel_fs(void)
1929{
1930        kobject_put(selinuxfs_kobj);
1931        kern_unmount(selinuxfs_mount);
1932        unregister_filesystem(&sel_fs_type);
1933}
1934#endif
1935
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