security/tomoyo/file.c

   1 /*
   2  * security/tomoyo/file.c
   3  *
   4  * Pathname restriction functions.
   5  *
   6  * Copyright (C) 2005-2010  NTT DATA CORPORATION
   7  */
   8
   9 #include "common.h"
  10 #include <linux/slab.h>
  11
  12 /* Keyword array for operations with one pathname. */
  13 static const char *tomoyo_path_keyword[TOMOYO_MAX_PATH_OPERATION] = {
  14         [TOMOYO_TYPE_READ_WRITE] = "read/write",
  15         [TOMOYO_TYPE_EXECUTE]    = "execute",
  16         [TOMOYO_TYPE_READ]       = "read",
  17         [TOMOYO_TYPE_WRITE]      = "write",
  18         [TOMOYO_TYPE_UNLINK]     = "unlink",
  19         [TOMOYO_TYPE_RMDIR]      = "rmdir",
  20         [TOMOYO_TYPE_TRUNCATE]   = "truncate",
  21         [TOMOYO_TYPE_SYMLINK]    = "symlink",
  22         [TOMOYO_TYPE_REWRITE]    = "rewrite",
  23         [TOMOYO_TYPE_CHROOT]     = "chroot",
  24         [TOMOYO_TYPE_UMOUNT]     = "unmount",
  25 };
  26
  27 /* Keyword array for operations with one pathname and three numbers. */
  28 static const char *tomoyo_mkdev_keyword
  29 [TOMOYO_MAX_MKDEV_OPERATION] = {
  30         [TOMOYO_TYPE_MKBLOCK]    = "mkblock",
  31         [TOMOYO_TYPE_MKCHAR]     = "mkchar",
  32 };
  33
  34 /* Keyword array for operations with two pathnames. */
  35 static const char *tomoyo_path2_keyword[TOMOYO_MAX_PATH2_OPERATION] = {
  36         [TOMOYO_TYPE_LINK]       = "link",
  37         [TOMOYO_TYPE_RENAME]     = "rename",
  38         [TOMOYO_TYPE_PIVOT_ROOT] = "pivot_root",
  39 };
  40
  41 /* Keyword array for operations with one pathname and one number. */
  42 static const char *tomoyo_path_number_keyword
  43 [TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
  44         [TOMOYO_TYPE_CREATE]     = "create",
  45         [TOMOYO_TYPE_MKDIR]      = "mkdir",
  46         [TOMOYO_TYPE_MKFIFO]     = "mkfifo",
  47         [TOMOYO_TYPE_MKSOCK]     = "mksock",
  48         [TOMOYO_TYPE_IOCTL]      = "ioctl",
  49         [TOMOYO_TYPE_CHMOD]      = "chmod",
  50         [TOMOYO_TYPE_CHOWN]      = "chown",
  51         [TOMOYO_TYPE_CHGRP]      = "chgrp",
  52 };
  53
  54 static const u8 tomoyo_p2mac[TOMOYO_MAX_PATH_OPERATION] = {
  55         [TOMOYO_TYPE_READ_WRITE] = TOMOYO_MAC_FILE_OPEN,
  56         [TOMOYO_TYPE_EXECUTE]    = TOMOYO_MAC_FILE_EXECUTE,
  57         [TOMOYO_TYPE_READ]       = TOMOYO_MAC_FILE_OPEN,
  58         [TOMOYO_TYPE_WRITE]      = TOMOYO_MAC_FILE_OPEN,
  59         [TOMOYO_TYPE_UNLINK]     = TOMOYO_MAC_FILE_UNLINK,
  60         [TOMOYO_TYPE_RMDIR]      = TOMOYO_MAC_FILE_RMDIR,
  61         [TOMOYO_TYPE_TRUNCATE]   = TOMOYO_MAC_FILE_TRUNCATE,
  62         [TOMOYO_TYPE_SYMLINK]    = TOMOYO_MAC_FILE_SYMLINK,
  63         [TOMOYO_TYPE_REWRITE]    = TOMOYO_MAC_FILE_REWRITE,
  64         [TOMOYO_TYPE_CHROOT]     = TOMOYO_MAC_FILE_CHROOT,
  65         [TOMOYO_TYPE_UMOUNT]     = TOMOYO_MAC_FILE_UMOUNT,
  66 };
  67
  68 static const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION] = {
  69         [TOMOYO_TYPE_MKBLOCK] = TOMOYO_MAC_FILE_MKBLOCK,
  70         [TOMOYO_TYPE_MKCHAR]  = TOMOYO_MAC_FILE_MKCHAR,
  71 };
  72
  73 static const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION] = {
  74         [TOMOYO_TYPE_LINK]       = TOMOYO_MAC_FILE_LINK,
  75         [TOMOYO_TYPE_RENAME]     = TOMOYO_MAC_FILE_RENAME,
  76         [TOMOYO_TYPE_PIVOT_ROOT] = TOMOYO_MAC_FILE_PIVOT_ROOT,
  77 };
  78
  79 static const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION] = {
  80         [TOMOYO_TYPE_CREATE] = TOMOYO_MAC_FILE_CREATE,
  81         [TOMOYO_TYPE_MKDIR]  = TOMOYO_MAC_FILE_MKDIR,
  82         [TOMOYO_TYPE_MKFIFO] = TOMOYO_MAC_FILE_MKFIFO,
  83         [TOMOYO_TYPE_MKSOCK] = TOMOYO_MAC_FILE_MKSOCK,
  84         [TOMOYO_TYPE_IOCTL]  = TOMOYO_MAC_FILE_IOCTL,
  85         [TOMOYO_TYPE_CHMOD]  = TOMOYO_MAC_FILE_CHMOD,
  86         [TOMOYO_TYPE_CHOWN]  = TOMOYO_MAC_FILE_CHOWN,
  87         [TOMOYO_TYPE_CHGRP]  = TOMOYO_MAC_FILE_CHGRP,
  88 };
  89
  90 void tomoyo_put_name_union(struct tomoyo_name_union *ptr)
  91 {
  92         if (!ptr)
  93                 return;
  94         if (ptr->is_group)
  95                 tomoyo_put_path_group(ptr->group);
  96         else
  97                 tomoyo_put_name(ptr->filename);
  98 }
  99
 100 bool tomoyo_compare_name_union(const struct tomoyo_path_info *name,
 101                                const struct tomoyo_name_union *ptr)
 102 {
 103         if (ptr->is_group)
 104                 return tomoyo_path_matches_group(name, ptr->group);
 105         return tomoyo_path_matches_pattern(name, ptr->filename);
 106 }
 107
 108 void tomoyo_put_number_union(struct tomoyo_number_union *ptr)
 109 {
 110         if (ptr && ptr->is_group)
 111                 tomoyo_put_number_group(ptr->group);
 112 }
 113
 114 bool tomoyo_compare_number_union(const unsigned long value,
 115                                  const struct tomoyo_number_union *ptr)
 116 {
 117         if (ptr->is_group)
 118                 return tomoyo_number_matches_group(value, value, ptr->group);
 119         return value >= ptr->values[0] && value <= ptr->values[1];
 120 }
 121
 122 /**
 123  * tomoyo_path2keyword - Get the name of single path operation.
 124  *
 125  * @operation: Type of operation.
 126  *
 127  * Returns the name of single path operation.
 128  */
 129 const char *tomoyo_path2keyword(const u8 operation)
 130 {
 131         return (operation < TOMOYO_MAX_PATH_OPERATION)
 132                 ? tomoyo_path_keyword[operation] : NULL;
 133 }
 134
 135 /**
 136  * tomoyo_mkdev2keyword - Get the name of path/number/number/number operations.
 137  *
 138  * @operation: Type of operation.
 139  *
 140  * Returns the name of path/number/number/number operation.
 141  */
 142 const char *tomoyo_mkdev2keyword(const u8 operation)
 143 {
 144         return (operation < TOMOYO_MAX_MKDEV_OPERATION)
 145                 ? tomoyo_mkdev_keyword[operation] : NULL;
 146 }
 147
 148 /**
 149  * tomoyo_path22keyword - Get the name of double path operation.
 150  *
 151  * @operation: Type of operation.
 152  *
 153  * Returns the name of double path operation.
 154  */
 155 const char *tomoyo_path22keyword(const u8 operation)
 156 {
 157         return (operation < TOMOYO_MAX_PATH2_OPERATION)
 158                 ? tomoyo_path2_keyword[operation] : NULL;
 159 }
 160
 161 /**
 162  * tomoyo_path_number2keyword - Get the name of path/number operations.
 163  *
 164  * @operation: Type of operation.
 165  *
 166  * Returns the name of path/number operation.
 167  */
 168 const char *tomoyo_path_number2keyword(const u8 operation)
 169 {
 170         return (operation < TOMOYO_MAX_PATH_NUMBER_OPERATION)
 171                 ? tomoyo_path_number_keyword[operation] : NULL;
 172 }
 173
 174 static void tomoyo_add_slash(struct tomoyo_path_info *buf)
 175 {
 176         if (buf->is_dir)
 177                 return;
 178         /*
 179          * This is OK because tomoyo_encode() reserves space for appending "/".
 180          */
 181         strcat((char *) buf->name, "/");
 182         tomoyo_fill_path_info(buf);
 183 }
 184
 185 /**
 186  * tomoyo_strendswith - Check whether the token ends with the given token.
 187  *
 188  * @name: The token to check.
 189  * @tail: The token to find.
 190  *
 191  * Returns true if @name ends with @tail, false otherwise.
 192  */
 193 static bool tomoyo_strendswith(const char *name, const char *tail)
 194 {
 195         int len;
 196
 197         if (!name || !tail)
 198                 return false;
 199         len = strlen(name) - strlen(tail);
 200         return len >= 0 && !strcmp(name + len, tail);
 201 }
 202
 203 /**
 204  * tomoyo_get_realpath - Get realpath.
 205  *
 206  * @buf:  Pointer to "struct tomoyo_path_info".
 207  * @path: Pointer to "struct path".
 208  *
 209  * Returns true on success, false otherwise.
 210  */
 211 static bool tomoyo_get_realpath(struct tomoyo_path_info *buf, struct path *path)
 212 {
 213         buf->name = tomoyo_realpath_from_path(path);
 214         if (buf->name) {
 215                 tomoyo_fill_path_info(buf);
 216                 return true;
 217         }
 218         return false;
 219 }
 220
 221 /**
 222  * tomoyo_audit_path_log - Audit path request log.
 223  *
 224  * @r: Pointer to "struct tomoyo_request_info".
 225  *
 226  * Returns 0 on success, negative value otherwise.
 227  */
 228 static int tomoyo_audit_path_log(struct tomoyo_request_info *r)
 229 {
 230         const char *operation = tomoyo_path_keyword[r->param.path.operation];
 231         const struct tomoyo_path_info *filename = r->param.path.filename;
 232         if (r->granted)
 233                 return 0;
 234         tomoyo_warn_log(r, "%s %s", operation, filename->name);
 235         return tomoyo_supervisor(r, "allow_%s %s\n", operation,
 236                                  tomoyo_file_pattern(filename));
 237 }
 238
 239 /**
 240  * tomoyo_audit_path2_log - Audit path/path request log.
 241  *
 242  * @r: Pointer to "struct tomoyo_request_info".
 243  *
 244  * Returns 0 on success, negative value otherwise.
 245  */
 246 static int tomoyo_audit_path2_log(struct tomoyo_request_info *r)
 247 {
 248         const char *operation = tomoyo_path2_keyword[r->param.path2.operation];
 249         const struct tomoyo_path_info *filename1 = r->param.path2.filename1;
 250         const struct tomoyo_path_info *filename2 = r->param.path2.filename2;
 251         if (r->granted)
 252                 return 0;
 253         tomoyo_warn_log(r, "%s %s %s", operation, filename1->name,
 254                         filename2->name);
 255         return tomoyo_supervisor(r, "allow_%s %s %s\n", operation,
 256                                  tomoyo_file_pattern(filename1),
 257                                  tomoyo_file_pattern(filename2));
 258 }
 259
 260 /**
 261  * tomoyo_audit_mkdev_log - Audit path/number/number/number request log.
 262  *
 263  * @r: Pointer to "struct tomoyo_request_info".
 264  *
 265  * Returns 0 on success, negative value otherwise.
 266  */
 267 static int tomoyo_audit_mkdev_log(struct tomoyo_request_info *r)
 268 {
 269         const char *operation = tomoyo_mkdev2keyword(r->param.mkdev.
 270                                                             operation);
 271         const struct tomoyo_path_info *filename = r->param.mkdev.filename;
 272         const unsigned int major = r->param.mkdev.major;
 273         const unsigned int minor = r->param.mkdev.minor;
 274         const unsigned int mode = r->param.mkdev.mode;
 275         if (r->granted)
 276                 return 0;
 277         tomoyo_warn_log(r, "%s %s 0%o %u %u", operation, filename->name, mode,
 278                         major, minor);
 279         return tomoyo_supervisor(r, "allow_%s %s 0%o %u %u\n", operation,
 280                                  tomoyo_file_pattern(filename), mode, major,
 281                                  minor);
 282 }
 283
 284 /**
 285  * tomoyo_audit_path_number_log - Audit path/number request log.
 286  *
 287  * @r:     Pointer to "struct tomoyo_request_info".
 288  * @error: Error code.
 289  *
 290  * Returns 0 on success, negative value otherwise.
 291  */
 292 static int tomoyo_audit_path_number_log(struct tomoyo_request_info *r)
 293 {
 294         const u8 type = r->param.path_number.operation;
 295         u8 radix;
 296         const struct tomoyo_path_info *filename = r->param.path_number.filename;
 297         const char *operation = tomoyo_path_number_keyword[type];
 298         char buffer[64];
 299         if (r->granted)
 300                 return 0;
 301         switch (type) {
 302         case TOMOYO_TYPE_CREATE:
 303         case TOMOYO_TYPE_MKDIR:
 304         case TOMOYO_TYPE_MKFIFO:
 305         case TOMOYO_TYPE_MKSOCK:
 306         case TOMOYO_TYPE_CHMOD:
 307                 radix = TOMOYO_VALUE_TYPE_OCTAL;
 308                 break;
 309         case TOMOYO_TYPE_IOCTL:
 310                 radix = TOMOYO_VALUE_TYPE_HEXADECIMAL;
 311                 break;
 312         default:
 313                 radix = TOMOYO_VALUE_TYPE_DECIMAL;
 314                 break;
 315         }
 316         tomoyo_print_ulong(buffer, sizeof(buffer), r->param.path_number.number,
 317                            radix);
 318         tomoyo_warn_log(r, "%s %s %s", operation, filename->name, buffer);
 319         return tomoyo_supervisor(r, "allow_%s %s %s\n", operation,
 320                                  tomoyo_file_pattern(filename), buffer);
 321 }
 322
 323 static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
 324                                    const char *filename2,
 325                                    struct tomoyo_domain_info *const domain,
 326                                    const bool is_delete);
 327 static int tomoyo_update_path_acl(const u8 type, const char *filename,
 328                                   struct tomoyo_domain_info *const domain,
 329                                   const bool is_delete);
 330
 331 /*
 332  * tomoyo_globally_readable_list is used for holding list of pathnames which
 333  * are by default allowed to be open()ed for reading by any process.
 334  *
 335  * An entry is added by
 336  *
 337  * # echo 'allow_read /lib/libc-2.5.so' > \
 338  *                               /sys/kernel/security/tomoyo/exception_policy
 339  *
 340  * and is deleted by
 341  *
 342  * # echo 'delete allow_read /lib/libc-2.5.so' > \
 343  *                               /sys/kernel/security/tomoyo/exception_policy
 344  *
 345  * and all entries are retrieved by
 346  *
 347  * # grep ^allow_read /sys/kernel/security/tomoyo/exception_policy
 348  *
 349  * In the example above, any process is allowed to
 350  * open("/lib/libc-2.5.so", O_RDONLY).
 351  * One exception is, if the domain which current process belongs to is marked
 352  * as "ignore_global_allow_read", current process can't do so unless explicitly
 353  * given "allow_read /lib/libc-2.5.so" to the domain which current process
 354  * belongs to.
 355  */
 356 LIST_HEAD(tomoyo_globally_readable_list);
 357
 358 static bool tomoyo_same_globally_readable(const struct tomoyo_acl_head *a,
 359                                           const struct tomoyo_acl_head *b)
 360 {
 361         return container_of(a, struct tomoyo_globally_readable_file_entry,
 362                             head)->filename ==
 363                 container_of(b, struct tomoyo_globally_readable_file_entry,
 364                              head)->filename;
 365 }
 366
 367 /**
 368  * tomoyo_update_globally_readable_entry - Update "struct tomoyo_globally_readable_file_entry" list.
 369  *
 370  * @filename:  Filename unconditionally permitted to open() for reading.
 371  * @is_delete: True if it is a delete request.
 372  *
 373  * Returns 0 on success, negative value otherwise.
 374  *
 375  * Caller holds tomoyo_read_lock().
 376  */
 377 static int tomoyo_update_globally_readable_entry(const char *filename,
 378                                                  const bool is_delete)
 379 {
 380         struct tomoyo_globally_readable_file_entry e = { };
 381         int error;
 382
 383         if (!tomoyo_correct_word(filename))
 384                 return -EINVAL;
 385         e.filename = tomoyo_get_name(filename);
 386         if (!e.filename)
 387                 return -ENOMEM;
 388         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
 389                                      &tomoyo_globally_readable_list,
 390                                      tomoyo_same_globally_readable);
 391         tomoyo_put_name(e.filename);
 392         return error;
 393 }
 394
 395 /**
 396  * tomoyo_globally_readable_file - Check if the file is unconditionnaly permitted to be open()ed for reading.
 397  *
 398  * @filename: The filename to check.
 399  *
 400  * Returns true if any domain can open @filename for reading, false otherwise.
 401  *
 402  * Caller holds tomoyo_read_lock().
 403  */
 404 static bool tomoyo_globally_readable_file(const struct tomoyo_path_info *
 405                                              filename)
 406 {
 407         struct tomoyo_globally_readable_file_entry *ptr;
 408         bool found = false;
 409
 410         list_for_each_entry_rcu(ptr, &tomoyo_globally_readable_list,
 411                                 head.list) {
 412                 if (!ptr->head.is_deleted &&
 413                     tomoyo_path_matches_pattern(filename, ptr->filename)) {
 414                         found = true;
 415                         break;
 416                 }
 417         }
 418         return found;
 419 }
 420
 421 /**
 422  * tomoyo_write_globally_readable_policy - Write "struct tomoyo_globally_readable_file_entry" list.
 423  *
 424  * @data:      String to parse.
 425  * @is_delete: True if it is a delete request.
 426  *
 427  * Returns 0 on success, negative value otherwise.
 428  *
 429  * Caller holds tomoyo_read_lock().
 430  */
 431 int tomoyo_write_globally_readable_policy(char *data, const bool is_delete)
 432 {
 433         return tomoyo_update_globally_readable_entry(data, is_delete);
 434 }
 435
 436 /**
 437  * tomoyo_read_globally_readable_policy - Read "struct tomoyo_globally_readable_file_entry" list.
 438  *
 439  * @head: Pointer to "struct tomoyo_io_buffer".
 440  *
 441  * Returns true on success, false otherwise.
 442  *
 443  * Caller holds tomoyo_read_lock().
 444  */
 445 bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head)
 446 {
 447         struct list_head *pos;
 448         bool done = true;
 449
 450         list_for_each_cookie(pos, head->read_var2,
 451                              &tomoyo_globally_readable_list) {
 452                 struct tomoyo_globally_readable_file_entry *ptr;
 453                 ptr = list_entry(pos,
 454                                  struct tomoyo_globally_readable_file_entry,
 455                                  head.list);
 456                 if (ptr->head.is_deleted)
 457                         continue;
 458                 done = tomoyo_io_printf(head, TOMOYO_KEYWORD_ALLOW_READ "%s\n",
 459                                         ptr->filename->name);
 460                 if (!done)
 461                         break;
 462         }
 463         return done;
 464 }
 465
 466 /* tomoyo_pattern_list is used for holding list of pathnames which are used for
 467  * converting pathnames to pathname patterns during learning mode.
 468  *
 469  * An entry is added by
 470  *
 471  * # echo 'file_pattern /proc/\$/mounts' > \
 472  *                             /sys/kernel/security/tomoyo/exception_policy
 473  *
 474  * and is deleted by
 475  *
 476  * # echo 'delete file_pattern /proc/\$/mounts' > \
 477  *                             /sys/kernel/security/tomoyo/exception_policy
 478  *
 479  * and all entries are retrieved by
 480  *
 481  * # grep ^file_pattern /sys/kernel/security/tomoyo/exception_policy
 482  *
 483  * In the example above, if a process which belongs to a domain which is in
 484  * learning mode requested open("/proc/1/mounts", O_RDONLY),
 485  * "allow_read /proc/\$/mounts" is automatically added to the domain which that
 486  * process belongs to.
 487  *
 488  * It is not a desirable behavior that we have to use /proc/\$/ instead of
 489  * /proc/self/ when current process needs to access only current process's
 490  * information. As of now, LSM version of TOMOYO is using __d_path() for
 491  * calculating pathname. Non LSM version of TOMOYO is using its own function
 492  * which pretends as if /proc/self/ is not a symlink; so that we can forbid
 493  * current process from accessing other process's information.
 494  */
 495 LIST_HEAD(tomoyo_pattern_list);
 496
 497 static bool tomoyo_same_pattern(const struct tomoyo_acl_head *a,
 498                                 const struct tomoyo_acl_head *b)
 499 {
 500         return container_of(a, struct tomoyo_pattern_entry, head)->pattern ==
 501                 container_of(b, struct tomoyo_pattern_entry, head)->pattern;
 502 }
 503
 504 /**
 505  * tomoyo_update_file_pattern_entry - Update "struct tomoyo_pattern_entry" list.
 506  *
 507  * @pattern:   Pathname pattern.
 508  * @is_delete: True if it is a delete request.
 509  *
 510  * Returns 0 on success, negative value otherwise.
 511  *
 512  * Caller holds tomoyo_read_lock().
 513  */
 514 static int tomoyo_update_file_pattern_entry(const char *pattern,
 515                                             const bool is_delete)
 516 {
 517         struct tomoyo_pattern_entry e = { };
 518         int error;
 519
 520         if (!tomoyo_correct_word(pattern))
 521                 return -EINVAL;
 522         e.pattern = tomoyo_get_name(pattern);
 523         if (!e.pattern)
 524                 return -ENOMEM;
 525         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
 526                                      &tomoyo_pattern_list,
 527                                      tomoyo_same_pattern);
 528         tomoyo_put_name(e.pattern);
 529         return error;
 530 }
 531
 532 /**
 533  * tomoyo_file_pattern - Get patterned pathname.
 534  *
 535  * @filename: The filename to find patterned pathname.
 536  *
 537  * Returns pointer to pathname pattern if matched, @filename otherwise.
 538  *
 539  * Caller holds tomoyo_read_lock().
 540  */
 541 const char *tomoyo_file_pattern(const struct tomoyo_path_info *filename)
 542 {
 543         struct tomoyo_pattern_entry *ptr;
 544         const struct tomoyo_path_info *pattern = NULL;
 545
 546         list_for_each_entry_rcu(ptr, &tomoyo_pattern_list, head.list) {
 547                 if (ptr->head.is_deleted)
 548                         continue;
 549                 if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
 550                         continue;
 551                 pattern = ptr->pattern;
 552                 if (tomoyo_strendswith(pattern->name, "/\\*")) {
 553                         /* Do nothing. Try to find the better match. */
 554                 } else {
 555                         /* This would be the better match. Use this. */
 556                         break;
 557                 }
 558         }
 559         if (pattern)
 560                 filename = pattern;
 561         return filename->name;
 562 }
 563
 564 /**
 565  * tomoyo_write_pattern_policy - Write "struct tomoyo_pattern_entry" list.
 566  *
 567  * @data:      String to parse.
 568  * @is_delete: True if it is a delete request.
 569  *
 570  * Returns 0 on success, negative value otherwise.
 571  *
 572  * Caller holds tomoyo_read_lock().
 573  */
 574 int tomoyo_write_pattern_policy(char *data, const bool is_delete)
 575 {
 576         return tomoyo_update_file_pattern_entry(data, is_delete);
 577 }
 578
 579 /**
 580  * tomoyo_read_file_pattern - Read "struct tomoyo_pattern_entry" list.
 581  *
 582  * @head: Pointer to "struct tomoyo_io_buffer".
 583  *
 584  * Returns true on success, false otherwise.
 585  *
 586  * Caller holds tomoyo_read_lock().
 587  */
 588 bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head)
 589 {
 590         struct list_head *pos;
 591         bool done = true;
 592
 593         list_for_each_cookie(pos, head->read_var2, &tomoyo_pattern_list) {
 594                 struct tomoyo_pattern_entry *ptr;
 595                 ptr = list_entry(pos, struct tomoyo_pattern_entry, head.list);
 596                 if (ptr->head.is_deleted)
 597                         continue;
 598                 done = tomoyo_io_printf(head, TOMOYO_KEYWORD_FILE_PATTERN
 599                                         "%s\n", ptr->pattern->name);
 600                 if (!done)
 601                         break;
 602         }
 603         return done;
 604 }
 605
 606 /*
 607  * tomoyo_no_rewrite_list is used for holding list of pathnames which are by
 608  * default forbidden to modify already written content of a file.
 609  *
 610  * An entry is added by
 611  *
 612  * # echo 'deny_rewrite /var/log/messages' > \
 613  *                              /sys/kernel/security/tomoyo/exception_policy
 614  *
 615  * and is deleted by
 616  *
 617  * # echo 'delete deny_rewrite /var/log/messages' > \
 618  *                              /sys/kernel/security/tomoyo/exception_policy
 619  *
 620  * and all entries are retrieved by
 621  *
 622  * # grep ^deny_rewrite /sys/kernel/security/tomoyo/exception_policy
 623  *
 624  * In the example above, if a process requested to rewrite /var/log/messages ,
 625  * the process can't rewrite unless the domain which that process belongs to
 626  * has "allow_rewrite /var/log/messages" entry.
 627  *
 628  * It is not a desirable behavior that we have to add "\040(deleted)" suffix
 629  * when we want to allow rewriting already unlink()ed file. As of now,
 630  * LSM version of TOMOYO is using __d_path() for calculating pathname.
 631  * Non LSM version of TOMOYO is using its own function which doesn't append
 632  * " (deleted)" suffix if the file is already unlink()ed; so that we don't
 633  * need to worry whether the file is already unlink()ed or not.
 634  */
 635 LIST_HEAD(tomoyo_no_rewrite_list);
 636
 637 static bool tomoyo_same_no_rewrite(const struct tomoyo_acl_head *a,
 638                                    const struct tomoyo_acl_head *b)
 639 {
 640         return container_of(a, struct tomoyo_no_rewrite_entry, head)->pattern
 641                 == container_of(b, struct tomoyo_no_rewrite_entry, head)
 642                 ->pattern;
 643 }
 644
 645 /**
 646  * tomoyo_update_no_rewrite_entry - Update "struct tomoyo_no_rewrite_entry" list.
 647  *
 648  * @pattern:   Pathname pattern that are not rewritable by default.
 649  * @is_delete: True if it is a delete request.
 650  *
 651  * Returns 0 on success, negative value otherwise.
 652  *
 653  * Caller holds tomoyo_read_lock().
 654  */
 655 static int tomoyo_update_no_rewrite_entry(const char *pattern,
 656                                           const bool is_delete)
 657 {
 658         struct tomoyo_no_rewrite_entry e = { };
 659         int error;
 660
 661         if (!tomoyo_correct_word(pattern))
 662                 return -EINVAL;
 663         e.pattern = tomoyo_get_name(pattern);
 664         if (!e.pattern)
 665                 return -ENOMEM;
 666         error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
 667                                      &tomoyo_no_rewrite_list,
 668                                      tomoyo_same_no_rewrite);
 669         tomoyo_put_name(e.pattern);
 670         return error;
 671 }
 672
 673 /**
 674  * tomoyo_no_rewrite_file - Check if the given pathname is not permitted to be rewrited.
 675  *
 676  * @filename: Filename to check.
 677  *
 678  * Returns true if @filename is specified by "deny_rewrite" directive,
 679  * false otherwise.
 680  *
 681  * Caller holds tomoyo_read_lock().
 682  */
 683 static bool tomoyo_no_rewrite_file(const struct tomoyo_path_info *filename)
 684 {
 685         struct tomoyo_no_rewrite_entry *ptr;
 686         bool found = false;
 687
 688         list_for_each_entry_rcu(ptr, &tomoyo_no_rewrite_list, head.list) {
 689                 if (ptr->head.is_deleted)
 690                         continue;
 691                 if (!tomoyo_path_matches_pattern(filename, ptr->pattern))
 692                         continue;
 693                 found = true;
 694                 break;
 695         }
 696         return found;
 697 }
 698
 699 /**
 700  * tomoyo_write_no_rewrite_policy - Write "struct tomoyo_no_rewrite_entry" list.
 701  *
 702  * @data:      String to parse.
 703  * @is_delete: True if it is a delete request.
 704  *
 705  * Returns 0 on success, negative value otherwise.
 706  *
 707  * Caller holds tomoyo_read_lock().
 708  */
 709 int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete)
 710 {
 711         return tomoyo_update_no_rewrite_entry(data, is_delete);
 712 }
 713
 714 /**
 715  * tomoyo_read_no_rewrite_policy - Read "struct tomoyo_no_rewrite_entry" list.
 716  *
 717  * @head: Pointer to "struct tomoyo_io_buffer".
 718  *
 719  * Returns true on success, false otherwise.
 720  *
 721  * Caller holds tomoyo_read_lock().
 722  */
 723 bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head)
 724 {
 725         struct list_head *pos;
 726         bool done = true;
 727
 728         list_for_each_cookie(pos, head->read_var2, &tomoyo_no_rewrite_list) {
 729                 struct tomoyo_no_rewrite_entry *ptr;
 730                 ptr = list_entry(pos, struct tomoyo_no_rewrite_entry,
 731                                  head.list);
 732                 if (ptr->head.is_deleted)
 733                         continue;
 734                 done = tomoyo_io_printf(head, TOMOYO_KEYWORD_DENY_REWRITE
 735                                         "%s\n", ptr->pattern->name);
 736                 if (!done)
 737                         break;
 738         }
 739         return done;
 740 }
 741
 742 static bool tomoyo_check_path_acl(const struct tomoyo_request_info *r,
 743                                   const struct tomoyo_acl_info *ptr)
 744 {
 745         const struct tomoyo_path_acl *acl = container_of(ptr, typeof(*acl),
 746                                                          head);
 747         return (acl->perm & (1 << r->param.path.operation)) &&
 748                 tomoyo_compare_name_union(r->param.path.filename, &acl->name);
 749 }
 750
 751 static bool tomoyo_check_path_number_acl(const struct tomoyo_request_info *r,
 752                                          const struct tomoyo_acl_info *ptr)
 753 {
 754         const struct tomoyo_path_number_acl *acl =
 755                 container_of(ptr, typeof(*acl), head);
 756         return (acl->perm & (1 << r->param.path_number.operation)) &&
 757                 tomoyo_compare_number_union(r->param.path_number.number,
 758                                             &acl->number) &&
 759                 tomoyo_compare_name_union(r->param.path_number.filename,
 760                                           &acl->name);
 761 }
 762
 763 static bool tomoyo_check_path2_acl(const struct tomoyo_request_info *r,
 764                                    const struct tomoyo_acl_info *ptr)
 765 {
 766         const struct tomoyo_path2_acl *acl =
 767                 container_of(ptr, typeof(*acl), head);
 768         return (acl->perm & (1 << r->param.path2.operation)) &&
 769                 tomoyo_compare_name_union(r->param.path2.filename1, &acl->name1)
 770                 && tomoyo_compare_name_union(r->param.path2.filename2,
 771                                              &acl->name2);
 772 }
 773
 774 static bool tomoyo_check_mkdev_acl(const struct tomoyo_request_info *r,
 775                                 const struct tomoyo_acl_info *ptr)
 776 {
 777         const struct tomoyo_mkdev_acl *acl =
 778                 container_of(ptr, typeof(*acl), head);
 779         return (acl->perm & (1 << r->param.mkdev.operation)) &&
 780                 tomoyo_compare_number_union(r->param.mkdev.mode,
 781                                             &acl->mode) &&
 782                 tomoyo_compare_number_union(r->param.mkdev.major,
 783                                             &acl->major) &&
 784                 tomoyo_compare_number_union(r->param.mkdev.minor,
 785                                             &acl->minor) &&
 786                 tomoyo_compare_name_union(r->param.mkdev.filename,
 787                                           &acl->name);
 788 }
 789
 790 static bool tomoyo_same_path_acl(const struct tomoyo_acl_info *a,
 791                                  const struct tomoyo_acl_info *b)
 792 {
 793         const struct tomoyo_path_acl *p1 = container_of(a, typeof(*p1), head);
 794         const struct tomoyo_path_acl *p2 = container_of(b, typeof(*p2), head);
 795         return tomoyo_same_acl_head(&p1->head, &p2->head) &&
 796                 tomoyo_same_name_union(&p1->name, &p2->name);
 797 }
 798
 799 static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
 800                                   struct tomoyo_acl_info *b,
 801                                   const bool is_delete)
 802 {
 803         u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
 804                 ->perm;
 805         u16 perm = *a_perm;
 806         const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
 807         if (is_delete) {
 808                 perm &= ~b_perm;
 809                 if ((perm & TOMOYO_RW_MASK) != TOMOYO_RW_MASK)
 810                         perm &= ~(1 << TOMOYO_TYPE_READ_WRITE);
 811                 else if (!(perm & (1 << TOMOYO_TYPE_READ_WRITE)))
 812                         perm &= ~TOMOYO_RW_MASK;
 813         } else {
 814                 perm |= b_perm;
 815                 if ((perm & TOMOYO_RW_MASK) == TOMOYO_RW_MASK)
 816                         perm |= (1 << TOMOYO_TYPE_READ_WRITE);
 817                 else if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
 818                         perm |= TOMOYO_RW_MASK;
 819         }
 820         *a_perm = perm;
 821         return !perm;
 822 }
 823
 824 /**
 825  * tomoyo_update_path_acl - Update "struct tomoyo_path_acl" list.
 826  *
 827  * @type:      Type of operation.
 828  * @filename:  Filename.
 829  * @domain:    Pointer to "struct tomoyo_domain_info".
 830  * @is_delete: True if it is a delete request.
 831  *
 832  * Returns 0 on success, negative value otherwise.
 833  *
 834  * Caller holds tomoyo_read_lock().
 835  */
 836 static int tomoyo_update_path_acl(const u8 type, const char *filename,
 837                                   struct tomoyo_domain_info * const domain,
 838                                   const bool is_delete)
 839 {
 840         struct tomoyo_path_acl e = {
 841                 .head.type = TOMOYO_TYPE_PATH_ACL,
 842                 .perm = 1 << type
 843         };
 844         int error;
 845         if (e.perm == (1 << TOMOYO_TYPE_READ_WRITE))
 846                 e.perm |= TOMOYO_RW_MASK;
 847         if (!tomoyo_parse_name_union(filename, &e.name))
 848                 return -EINVAL;
 849         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
 850                                      tomoyo_same_path_acl,
 851                                      tomoyo_merge_path_acl);
 852         tomoyo_put_name_union(&e.name);
 853         return error;
 854 }
 855
 856 static bool tomoyo_same_mkdev_acl(const struct tomoyo_acl_info *a,
 857                                          const struct tomoyo_acl_info *b)
 858 {
 859         const struct tomoyo_mkdev_acl *p1 = container_of(a, typeof(*p1),
 860                                                                 head);
 861         const struct tomoyo_mkdev_acl *p2 = container_of(b, typeof(*p2),
 862                                                                 head);
 863         return tomoyo_same_acl_head(&p1->head, &p2->head)
 864                 && tomoyo_same_name_union(&p1->name, &p2->name)
 865                 && tomoyo_same_number_union(&p1->mode, &p2->mode)
 866                 && tomoyo_same_number_union(&p1->major, &p2->major)
 867                 && tomoyo_same_number_union(&p1->minor, &p2->minor);
 868 }
 869
 870 static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
 871                                           struct tomoyo_acl_info *b,
 872                                           const bool is_delete)
 873 {
 874         u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
 875                                          head)->perm;
 876         u8 perm = *a_perm;
 877         const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
 878                 ->perm;
 879         if (is_delete)
 880                 perm &= ~b_perm;
 881         else
 882                 perm |= b_perm;
 883         *a_perm = perm;
 884         return !perm;
 885 }
 886
 887 /**
 888  * tomoyo_update_mkdev_acl - Update "struct tomoyo_mkdev_acl" list.
 889  *
 890  * @type:      Type of operation.
 891  * @filename:  Filename.
 892  * @mode:      Create mode.
 893  * @major:     Device major number.
 894  * @minor:     Device minor number.
 895  * @domain:    Pointer to "struct tomoyo_domain_info".
 896  * @is_delete: True if it is a delete request.
 897  *
 898  * Returns 0 on success, negative value otherwise.
 899  *
 900  * Caller holds tomoyo_read_lock().
 901  */
 902 static int tomoyo_update_mkdev_acl(const u8 type, const char *filename,
 903                                           char *mode, char *major, char *minor,
 904                                           struct tomoyo_domain_info * const
 905                                           domain, const bool is_delete)
 906 {
 907         struct tomoyo_mkdev_acl e = {
 908                 .head.type = TOMOYO_TYPE_MKDEV_ACL,
 909                 .perm = 1 << type
 910         };
 911         int error = is_delete ? -ENOENT : -ENOMEM;
 912         if (!tomoyo_parse_name_union(filename, &e.name) ||
 913             !tomoyo_parse_number_union(mode, &e.mode) ||
 914             !tomoyo_parse_number_union(major, &e.major) ||
 915             !tomoyo_parse_number_union(minor, &e.minor))
 916                 goto out;
 917         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
 918                                      tomoyo_same_mkdev_acl,
 919                                      tomoyo_merge_mkdev_acl);
 920  out:
 921         tomoyo_put_name_union(&e.name);
 922         tomoyo_put_number_union(&e.mode);
 923         tomoyo_put_number_union(&e.major);
 924         tomoyo_put_number_union(&e.minor);
 925         return error;
 926 }
 927
 928 static bool tomoyo_same_path2_acl(const struct tomoyo_acl_info *a,
 929                                   const struct tomoyo_acl_info *b)
 930 {
 931         const struct tomoyo_path2_acl *p1 = container_of(a, typeof(*p1), head);
 932         const struct tomoyo_path2_acl *p2 = container_of(b, typeof(*p2), head);
 933         return tomoyo_same_acl_head(&p1->head, &p2->head)
 934                 && tomoyo_same_name_union(&p1->name1, &p2->name1)
 935                 && tomoyo_same_name_union(&p1->name2, &p2->name2);
 936 }
 937
 938 static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
 939                                    struct tomoyo_acl_info *b,
 940                                    const bool is_delete)
 941 {
 942         u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
 943                 ->perm;
 944         u8 perm = *a_perm;
 945         const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
 946         if (is_delete)
 947                 perm &= ~b_perm;
 948         else
 949                 perm |= b_perm;
 950         *a_perm = perm;
 951         return !perm;
 952 }
 953
 954 /**
 955  * tomoyo_update_path2_acl - Update "struct tomoyo_path2_acl" list.
 956  *
 957  * @type:      Type of operation.
 958  * @filename1: First filename.
 959  * @filename2: Second filename.
 960  * @domain:    Pointer to "struct tomoyo_domain_info".
 961  * @is_delete: True if it is a delete request.
 962  *
 963  * Returns 0 on success, negative value otherwise.
 964  *
 965  * Caller holds tomoyo_read_lock().
 966  */
 967 static int tomoyo_update_path2_acl(const u8 type, const char *filename1,
 968                                    const char *filename2,
 969                                    struct tomoyo_domain_info * const domain,
 970                                    const bool is_delete)
 971 {
 972         struct tomoyo_path2_acl e = {
 973                 .head.type = TOMOYO_TYPE_PATH2_ACL,
 974                 .perm = 1 << type
 975         };
 976         int error = is_delete ? -ENOENT : -ENOMEM;
 977         if (!tomoyo_parse_name_union(filename1, &e.name1) ||
 978             !tomoyo_parse_name_union(filename2, &e.name2))
 979                 goto out;
 980         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
 981                                      tomoyo_same_path2_acl,
 982                                      tomoyo_merge_path2_acl);
 983  out:
 984         tomoyo_put_name_union(&e.name1);
 985         tomoyo_put_name_union(&e.name2);
 986         return error;
 987 }
 988
 989 /**
 990  * tomoyo_path_permission - Check permission for single path operation.
 991  *
 992  * @r:         Pointer to "struct tomoyo_request_info".
 993  * @operation: Type of operation.
 994  * @filename:  Filename to check.
 995  *
 996  * Returns 0 on success, negative value otherwise.
 997  *
 998  * Caller holds tomoyo_read_lock().
 999  */
1000 int tomoyo_path_permission(struct tomoyo_request_info *r, u8 operation,
1001                            const struct tomoyo_path_info *filename)
1002 {
1003         int error;
1004
1005  next:
1006         r->type = tomoyo_p2mac[operation];
1007         r->mode = tomoyo_get_mode(r->profile, r->type);
1008         if (r->mode == TOMOYO_CONFIG_DISABLED)
1009                 return 0;
1010         r->param_type = TOMOYO_TYPE_PATH_ACL;
1011         r->param.path.filename = filename;
1012         r->param.path.operation = operation;
1013         do {
1014                 tomoyo_check_acl(r, tomoyo_check_path_acl);
1015                 if (!r->granted && operation == TOMOYO_TYPE_READ &&
1016                     !r->domain->ignore_global_allow_read &&
1017                     tomoyo_globally_readable_file(filename))
1018                         r->granted = true;
1019                 error = tomoyo_audit_path_log(r);
1020                 /*
1021                  * Do not retry for execute request, for alias may have
1022                  * changed.
1023                  */
1024         } while (error == TOMOYO_RETRY_REQUEST &&
1025                  operation != TOMOYO_TYPE_EXECUTE);
1026         /*
1027          * Since "allow_truncate" doesn't imply "allow_rewrite" permission,
1028          * we need to check "allow_rewrite" permission if the filename is
1029          * specified by "deny_rewrite" keyword.
1030          */
1031         if (!error && operation == TOMOYO_TYPE_TRUNCATE &&
1032             tomoyo_no_rewrite_file(filename)) {
1033                 operation = TOMOYO_TYPE_REWRITE;
1034                 goto next;
1035         }
1036         return error;
1037 }
1038
1039 static bool tomoyo_same_path_number_acl(const struct tomoyo_acl_info *a,
1040                                         const struct tomoyo_acl_info *b)
1041 {
1042         const struct tomoyo_path_number_acl *p1 = container_of(a, typeof(*p1),
1043                                                                head);
1044         const struct tomoyo_path_number_acl *p2 = container_of(b, typeof(*p2),
1045                                                                head);
1046         return tomoyo_same_acl_head(&p1->head, &p2->head)
1047                 && tomoyo_same_name_union(&p1->name, &p2->name)
1048                 && tomoyo_same_number_union(&p1->number, &p2->number);
1049 }
1050
1051 static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
1052                                          struct tomoyo_acl_info *b,
1053                                          const bool is_delete)
1054 {
1055         u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
1056                                           head)->perm;
1057         u8 perm = *a_perm;
1058         const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
1059                 ->perm;
1060         if (is_delete)
1061                 perm &= ~b_perm;
1062         else
1063                 perm |= b_perm;
1064         *a_perm = perm;
1065         return !perm;
1066 }
1067
1068 /**
1069  * tomoyo_update_path_number_acl - Update ioctl/chmod/chown/chgrp ACL.
1070  *
1071  * @type:      Type of operation.
1072  * @filename:  Filename.
1073  * @number:    Number.
1074  * @domain:    Pointer to "struct tomoyo_domain_info".
1075  * @is_delete: True if it is a delete request.
1076  *
1077  * Returns 0 on success, negative value otherwise.
1078  */
1079 static int tomoyo_update_path_number_acl(const u8 type, const char *filename,
1080                                          char *number,
1081                                          struct tomoyo_domain_info * const
1082                                          domain,
1083                                          const bool is_delete)
1084 {
1085         struct tomoyo_path_number_acl e = {
1086                 .head.type = TOMOYO_TYPE_PATH_NUMBER_ACL,
1087                 .perm = 1 << type
1088         };
1089         int error = is_delete ? -ENOENT : -ENOMEM;
1090         if (!tomoyo_parse_name_union(filename, &e.name))
1091                 return -EINVAL;
1092         if (!tomoyo_parse_number_union(number, &e.number))
1093                 goto out;
1094         error = tomoyo_update_domain(&e.head, sizeof(e), is_delete, domain,
1095                                      tomoyo_same_path_number_acl,
1096                                      tomoyo_merge_path_number_acl);
1097  out:
1098         tomoyo_put_name_union(&e.name);
1099         tomoyo_put_number_union(&e.number);
1100         return error;
1101 }
1102
1103 /**
1104  * tomoyo_path_number_perm2 - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
1105  *
1106  * @r:        Pointer to "strct tomoyo_request_info".
1107  * @filename: Filename to check.
1108  * @number:   Number.
1109  *
1110  * Returns 0 on success, negative value otherwise.
1111  *
1112  * Caller holds tomoyo_read_lock().
1113  */
1114 static int tomoyo_path_number_perm2(struct tomoyo_request_info *r,
1115                                     const u8 type,
1116                                     const struct tomoyo_path_info *filename,
1117                                     const unsigned long number)
1118 {
1119         int error;
1120
1121         if (!filename)
1122                 return 0;
1123         r->param_type = TOMOYO_TYPE_PATH_NUMBER_ACL;
1124         r->param.path_number.operation = type;
1125         r->param.path_number.filename = filename;
1126         r->param.path_number.number = number;
1127         do {
1128                 tomoyo_check_acl(r, tomoyo_check_path_number_acl);
1129                 error = tomoyo_audit_path_number_log(r);
1130         } while (error == TOMOYO_RETRY_REQUEST);
1131         return error;
1132 }
1133
1134 /**
1135  * tomoyo_path_number_perm - Check permission for "create", "mkdir", "mkfifo", "mksock", "ioctl", "chmod", "chown", "chgrp".
1136  *
1137  * @type:   Type of operation.
1138  * @path:   Pointer to "struct path".
1139  * @number: Number.
1140  *
1141  * Returns 0 on success, negative value otherwise.
1142  */
1143 int tomoyo_path_number_perm(const u8 type, struct path *path,
1144                             unsigned long number)
1145 {
1146         struct tomoyo_request_info r;
1147         int error = -ENOMEM;
1148         struct tomoyo_path_info buf;
1149         int idx;
1150
1151         if (tomoyo_init_request_info(&r, NULL, tomoyo_pn2mac[type])
1152             == TOMOYO_CONFIG_DISABLED || !path->mnt || !path->dentry)
1153                 return 0;
1154         idx = tomoyo_read_lock();
1155         if (!tomoyo_get_realpath(&buf, path))
1156                 goto out;
1157         if (type == TOMOYO_TYPE_MKDIR)
1158                 tomoyo_add_slash(&buf);
1159         error = tomoyo_path_number_perm2(&r, type, &buf, number);
1160  out:
1161         kfree(buf.name);
1162         tomoyo_read_unlock(idx);
1163         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1164                 error = 0;
1165         return error;
1166 }
1167
1168 /**
1169  * tomoyo_check_open_permission - Check permission for "read" and "write".
1170  *
1171  * @domain: Pointer to "struct tomoyo_domain_info".
1172  * @path:   Pointer to "struct path".
1173  * @flag:   Flags for open().
1174  *
1175  * Returns 0 on success, negative value otherwise.
1176  */
1177 int tomoyo_check_open_permission(struct tomoyo_domain_info *domain,
1178                                  struct path *path, const int flag)
1179 {
1180         const u8 acc_mode = ACC_MODE(flag);
1181         int error = -ENOMEM;
1182         struct tomoyo_path_info buf;
1183         struct tomoyo_request_info r;
1184         int idx;
1185
1186         if (!path->mnt ||
1187             (path->dentry->d_inode && S_ISDIR(path->dentry->d_inode->i_mode)))
1188                 return 0;
1189         buf.name = NULL;
1190         r.mode = TOMOYO_CONFIG_DISABLED;
1191         idx = tomoyo_read_lock();
1192         if (!tomoyo_get_realpath(&buf, path))
1193                 goto out;
1194         error = 0;
1195         /*
1196          * If the filename is specified by "deny_rewrite" keyword,
1197          * we need to check "allow_rewrite" permission when the filename is not
1198          * opened for append mode or the filename is truncated at open time.
1199          */
1200         if ((acc_mode & MAY_WRITE) && !(flag & O_APPEND)
1201             && tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_REWRITE)
1202             != TOMOYO_CONFIG_DISABLED) {
1203                 if (!tomoyo_get_realpath(&buf, path)) {
1204                         error = -ENOMEM;
1205                         goto out;
1206                 }
1207                 if (tomoyo_no_rewrite_file(&buf))
1208                         error = tomoyo_path_permission(&r, TOMOYO_TYPE_REWRITE,
1209                                                        &buf);
1210         }
1211         if (!error && acc_mode &&
1212             tomoyo_init_request_info(&r, domain, TOMOYO_MAC_FILE_OPEN)
1213             != TOMOYO_CONFIG_DISABLED) {
1214                 u8 operation;
1215                 if (!buf.name && !tomoyo_get_realpath(&buf, path)) {
1216                         error = -ENOMEM;
1217                         goto out;
1218                 }
1219                 if (acc_mode == (MAY_READ | MAY_WRITE))
1220                         operation = TOMOYO_TYPE_READ_WRITE;
1221                 else if (acc_mode == MAY_READ)
1222                         operation = TOMOYO_TYPE_READ;
1223                 else
1224                         operation = TOMOYO_TYPE_WRITE;
1225                 error = tomoyo_path_permission(&r, operation, &buf);
1226         }
1227  out:
1228         kfree(buf.name);
1229         tomoyo_read_unlock(idx);
1230         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1231                 error = 0;
1232         return error;
1233 }
1234
1235 /**
1236  * tomoyo_path_perm - Check permission for "unlink", "rmdir", "truncate", "symlink", "rewrite", "chroot" and "unmount".
1237  *
1238  * @operation: Type of operation.
1239  * @path:      Pointer to "struct path".
1240  *
1241  * Returns 0 on success, negative value otherwise.
1242  */
1243 int tomoyo_path_perm(const u8 operation, struct path *path)
1244 {
1245         int error = -ENOMEM;
1246         struct tomoyo_path_info buf;
1247         struct tomoyo_request_info r;
1248         int idx;
1249
1250         if (!path->mnt)
1251                 return 0;
1252         if (tomoyo_init_request_info(&r, NULL, tomoyo_p2mac[operation])
1253             == TOMOYO_CONFIG_DISABLED)
1254                 return 0;
1255         buf.name = NULL;
1256         idx = tomoyo_read_lock();
1257         if (!tomoyo_get_realpath(&buf, path))
1258                 goto out;
1259         switch (operation) {
1260         case TOMOYO_TYPE_REWRITE:
1261                 if (!tomoyo_no_rewrite_file(&buf)) {
1262                         error = 0;
1263                         goto out;
1264                 }
1265                 break;
1266         case TOMOYO_TYPE_RMDIR:
1267         case TOMOYO_TYPE_CHROOT:
1268         case TOMOYO_TYPE_UMOUNT:
1269                 tomoyo_add_slash(&buf);
1270                 break;
1271         }
1272         error = tomoyo_path_permission(&r, operation, &buf);
1273  out:
1274         kfree(buf.name);
1275         tomoyo_read_unlock(idx);
1276         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1277                 error = 0;
1278         return error;
1279 }
1280
1281 /**
1282  * tomoyo_mkdev_perm - Check permission for "mkblock" and "mkchar".
1283  *
1284  * @operation: Type of operation. (TOMOYO_TYPE_MKCHAR or TOMOYO_TYPE_MKBLOCK)
1285  * @path:      Pointer to "struct path".
1286  * @mode:      Create mode.
1287  * @dev:       Device number.
1288  *
1289  * Returns 0 on success, negative value otherwise.
1290  */
1291 int tomoyo_mkdev_perm(const u8 operation, struct path *path,
1292                              const unsigned int mode, unsigned int dev)
1293 {
1294         struct tomoyo_request_info r;
1295         int error = -ENOMEM;
1296         struct tomoyo_path_info buf;
1297         int idx;
1298
1299         if (!path->mnt ||
1300             tomoyo_init_request_info(&r, NULL, tomoyo_pnnn2mac[operation])
1301             == TOMOYO_CONFIG_DISABLED)
1302                 return 0;
1303         idx = tomoyo_read_lock();
1304         error = -ENOMEM;
1305         if (tomoyo_get_realpath(&buf, path)) {
1306                 dev = new_decode_dev(dev);
1307                 r.param_type = TOMOYO_TYPE_MKDEV_ACL;
1308                 r.param.mkdev.filename = &buf;
1309                 r.param.mkdev.operation = operation;
1310                 r.param.mkdev.mode = mode;
1311                 r.param.mkdev.major = MAJOR(dev);
1312                 r.param.mkdev.minor = MINOR(dev);
1313                 tomoyo_check_acl(&r, tomoyo_check_mkdev_acl);
1314                 error = tomoyo_audit_mkdev_log(&r);
1315                 kfree(buf.name);
1316         }
1317         tomoyo_read_unlock(idx);
1318         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1319                 error = 0;
1320         return error;
1321 }
1322
1323 /**
1324  * tomoyo_path2_perm - Check permission for "rename", "link" and "pivot_root".
1325  *
1326  * @operation: Type of operation.
1327  * @path1:      Pointer to "struct path".
1328  * @path2:      Pointer to "struct path".
1329  *
1330  * Returns 0 on success, negative value otherwise.
1331  */
1332 int tomoyo_path2_perm(const u8 operation, struct path *path1,
1333                       struct path *path2)
1334 {
1335         int error = -ENOMEM;
1336         struct tomoyo_path_info buf1;
1337         struct tomoyo_path_info buf2;
1338         struct tomoyo_request_info r;
1339         int idx;
1340
1341         if (!path1->mnt || !path2->mnt ||
1342             tomoyo_init_request_info(&r, NULL, tomoyo_pp2mac[operation])
1343             == TOMOYO_CONFIG_DISABLED)
1344                 return 0;
1345         buf1.name = NULL;
1346         buf2.name = NULL;
1347         idx = tomoyo_read_lock();
1348         if (!tomoyo_get_realpath(&buf1, path1) ||
1349             !tomoyo_get_realpath(&buf2, path2))
1350                 goto out;
1351         switch (operation) {
1352                 struct dentry *dentry;
1353         case TOMOYO_TYPE_RENAME:
1354         case TOMOYO_TYPE_LINK:
1355                 dentry = path1->dentry;
1356                 if (!dentry->d_inode || !S_ISDIR(dentry->d_inode->i_mode))
1357                         break;
1358                 /* fall through */
1359         case TOMOYO_TYPE_PIVOT_ROOT:
1360                 tomoyo_add_slash(&buf1);
1361                 tomoyo_add_slash(&buf2);
1362                 break;
1363         }
1364         r.param_type = TOMOYO_TYPE_PATH2_ACL;
1365         r.param.path2.operation = operation;
1366         r.param.path2.filename1 = &buf1;
1367         r.param.path2.filename2 = &buf2;
1368         do {
1369                 tomoyo_check_acl(&r, tomoyo_check_path2_acl);
1370                 error = tomoyo_audit_path2_log(&r);
1371         } while (error == TOMOYO_RETRY_REQUEST);
1372  out:
1373         kfree(buf1.name);
1374         kfree(buf2.name);
1375         tomoyo_read_unlock(idx);
1376         if (r.mode != TOMOYO_CONFIG_ENFORCING)
1377                 error = 0;
1378         return error;
1379 }
1380
1381 /**
1382  * tomoyo_write_file_policy - Update file related list.
1383  *
1384  * @data:      String to parse.
1385  * @domain:    Pointer to "struct tomoyo_domain_info".
1386  * @is_delete: True if it is a delete request.
1387  *
1388  * Returns 0 on success, negative value otherwise.
1389  *
1390  * Caller holds tomoyo_read_lock().
1391  */
1392 int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
1393                              const bool is_delete)
1394 {
1395         char *w[5];
1396         u8 type;
1397         if (!tomoyo_tokenize(data, w, sizeof(w)) || !w[1][0])
1398                 return -EINVAL;
1399         if (strncmp(w[0], "allow_", 6))
1400                 goto out;
1401         w[0] += 6;
1402         for (type = 0; type < TOMOYO_MAX_PATH_OPERATION; type++) {
1403                 if (strcmp(w[0], tomoyo_path_keyword[type]))
1404                         continue;
1405                 return tomoyo_update_path_acl(type, w[1], domain, is_delete);
1406         }
1407         if (!w[2][0])
1408                 goto out;
1409         for (type = 0; type < TOMOYO_MAX_PATH2_OPERATION; type++) {
1410                 if (strcmp(w[0], tomoyo_path2_keyword[type]))
1411                         continue;
1412                 return tomoyo_update_path2_acl(type, w[1], w[2], domain,
1413                                                is_delete);
1414         }
1415         for (type = 0; type < TOMOYO_MAX_PATH_NUMBER_OPERATION; type++) {
1416                 if (strcmp(w[0], tomoyo_path_number_keyword[type]))
1417                         continue;
1418                 return tomoyo_update_path_number_acl(type, w[1], w[2], domain,
1419                                                      is_delete);
1420         }
1421         if (!w[3][0] || !w[4][0])
1422                 goto out;
1423         for (type = 0; type < TOMOYO_MAX_MKDEV_OPERATION; type++) {
1424                 if (strcmp(w[0], tomoyo_mkdev_keyword[type]))
1425                         continue;
1426                 return tomoyo_update_mkdev_acl(type, w[1], w[2], w[3],
1427                                                w[4], domain, is_delete);
1428         }
1429  out:
1430         return -EINVAL;
1431 }