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