security/tomoyo/util.c

   1 /*
   2  * security/tomoyo/util.c
   3  *
   4  * Utility functions for TOMOYO.
   5  *
   6  * Copyright (C) 2005-2010  NTT DATA CORPORATION
   7  */
   8
   9 #include <linux/slab.h>
  10 #include "common.h"
  11
  12 /* Lock for protecting policy. */
  13 DEFINE_MUTEX(tomoyo_policy_lock);
  14
  15 /* Has /sbin/init started? */
  16 bool tomoyo_policy_loaded;
  17
  18 /*
  19  * Mapping table from "enum tomoyo_mac_index" to
  20  * "enum tomoyo_mac_category_index".
  21  */
  22 const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
  23         /* CONFIG::file group */
  24         [TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
  25         [TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
  26         [TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
  27         [TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
  28         [TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
  29         [TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
  30         [TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
  31         [TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
  32         [TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
  33         [TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
  34         [TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
  35         [TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
  36         [TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
  37         [TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
  38         [TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
  39         [TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
  40         [TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
  41         [TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
  42         [TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
  43         [TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
  44         [TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
  45         [TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
  46         [TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
  47 };
  48
  49 /**
  50  * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
  51  *
  52  * @time:  Seconds since 1970/01/01 00:00:00.
  53  * @stamp: Pointer to "struct tomoyo_time".
  54  *
  55  * Returns nothing.
  56  *
  57  * This function does not handle Y2038 problem.
  58  */
  59 void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
  60 {
  61         static const u16 tomoyo_eom[2][12] = {
  62                 { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
  63                 { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
  64         };
  65         u16 y;
  66         u8 m;
  67         bool r;
  68         stamp->sec = time % 60;
  69         time /= 60;
  70         stamp->min = time % 60;
  71         time /= 60;
  72         stamp->hour = time % 24;
  73         time /= 24;
  74         for (y = 1970; ; y++) {
  75                 const unsigned short days = (y & 3) ? 365 : 366;
  76                 if (time < days)
  77                         break;
  78                 time -= days;
  79         }
  80         r = (y & 3) == 0;
  81         for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
  82                 ;
  83         if (m)
  84                 time -= tomoyo_eom[r][m - 1];
  85         stamp->year = y;
  86         stamp->month = ++m;
  87         stamp->day = ++time;
  88 }
  89
  90 /**
  91  * tomoyo_permstr - Find permission keywords.
  92  *
  93  * @string: String representation for permissions in foo/bar/buz format.
  94  * @keyword: Keyword to find from @string/
  95  *
  96  * Returns ture if @keyword was found in @string, false otherwise.
  97  *
  98  * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
  99  */
 100 bool tomoyo_permstr(const char *string, const char *keyword)
 101 {
 102         const char *cp = strstr(string, keyword);
 103         if (cp)
 104                 return cp == string || *(cp - 1) == '/';
 105         return false;
 106 }
 107
 108 /**
 109  * tomoyo_read_token - Read a word from a line.
 110  *
 111  * @param: Pointer to "struct tomoyo_acl_param".
 112  *
 113  * Returns a word on success, "" otherwise.
 114  *
 115  * To allow the caller to skip NULL check, this function returns "" rather than
 116  * NULL if there is no more words to read.
 117  */
 118 char *tomoyo_read_token(struct tomoyo_acl_param *param)
 119 {
 120         char *pos = param->data;
 121         char *del = strchr(pos, ' ');
 122         if (del)
 123                 *del++ = '\0';
 124         else
 125                 del = pos + strlen(pos);
 126         param->data = del;
 127         return pos;
 128 }
 129
 130 /**
 131  * tomoyo_parse_ulong - Parse an "unsigned long" value.
 132  *
 133  * @result: Pointer to "unsigned long".
 134  * @str:    Pointer to string to parse.
 135  *
 136  * Returns one of values in "enum tomoyo_value_type".
 137  *
 138  * The @src is updated to point the first character after the value
 139  * on success.
 140  */
 141 u8 tomoyo_parse_ulong(unsigned long *result, char **str)
 142 {
 143         const char *cp = *str;
 144         char *ep;
 145         int base = 10;
 146         if (*cp == '0') {
 147                 char c = *(cp + 1);
 148                 if (c == 'x' || c == 'X') {
 149                         base = 16;
 150                         cp += 2;
 151                 } else if (c >= '0' && c <= '7') {
 152                         base = 8;
 153                         cp++;
 154                 }
 155         }
 156         *result = simple_strtoul(cp, &ep, base);
 157         if (cp == ep)
 158                 return TOMOYO_VALUE_TYPE_INVALID;
 159         *str = ep;
 160         switch (base) {
 161         case 16:
 162                 return TOMOYO_VALUE_TYPE_HEXADECIMAL;
 163         case 8:
 164                 return TOMOYO_VALUE_TYPE_OCTAL;
 165         default:
 166                 return TOMOYO_VALUE_TYPE_DECIMAL;
 167         }
 168 }
 169
 170 /**
 171  * tomoyo_print_ulong - Print an "unsigned long" value.
 172  *
 173  * @buffer:     Pointer to buffer.
 174  * @buffer_len: Size of @buffer.
 175  * @value:      An "unsigned long" value.
 176  * @type:       Type of @value.
 177  *
 178  * Returns nothing.
 179  */
 180 void tomoyo_print_ulong(char *buffer, const int buffer_len,
 181                         const unsigned long value, const u8 type)
 182 {
 183         if (type == TOMOYO_VALUE_TYPE_DECIMAL)
 184                 snprintf(buffer, buffer_len, "%lu", value);
 185         else if (type == TOMOYO_VALUE_TYPE_OCTAL)
 186                 snprintf(buffer, buffer_len, "0%lo", value);
 187         else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
 188                 snprintf(buffer, buffer_len, "0x%lX", value);
 189         else
 190                 snprintf(buffer, buffer_len, "type(%u)", type);
 191 }
 192
 193 /**
 194  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
 195  *
 196  * @param: Pointer to "struct tomoyo_acl_param".
 197  * @ptr:   Pointer to "struct tomoyo_name_union".
 198  *
 199  * Returns true on success, false otherwise.
 200  */
 201 bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
 202                              struct tomoyo_name_union *ptr)
 203 {
 204         char *filename;
 205         if (param->data[0] == '@') {
 206                 param->data++;
 207                 ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
 208                 return ptr->group != NULL;
 209         }
 210         filename = tomoyo_read_token(param);
 211         if (!tomoyo_correct_word(filename))
 212                 return false;
 213         ptr->filename = tomoyo_get_name(filename);
 214         return ptr->filename != NULL;
 215 }
 216
 217 /**
 218  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
 219  *
 220  * @param: Pointer to "struct tomoyo_acl_param".
 221  * @ptr:   Pointer to "struct tomoyo_number_union".
 222  *
 223  * Returns true on success, false otherwise.
 224  */
 225 bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
 226                                struct tomoyo_number_union *ptr)
 227 {
 228         char *data;
 229         u8 type;
 230         unsigned long v;
 231         memset(ptr, 0, sizeof(*ptr));
 232         if (param->data[0] == '@') {
 233                 param->data++;
 234                 ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
 235                 return ptr->group != NULL;
 236         }
 237         data = tomoyo_read_token(param);
 238         type = tomoyo_parse_ulong(&v, &data);
 239         if (type == TOMOYO_VALUE_TYPE_INVALID)
 240                 return false;
 241         ptr->values[0] = v;
 242         ptr->value_type[0] = type;
 243         if (!*data) {
 244                 ptr->values[1] = v;
 245                 ptr->value_type[1] = type;
 246                 return true;
 247         }
 248         if (*data++ != '-')
 249                 return false;
 250         type = tomoyo_parse_ulong(&v, &data);
 251         if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
 252                 return false;
 253         ptr->values[1] = v;
 254         ptr->value_type[1] = type;
 255         return true;
 256 }
 257
 258 /**
 259  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
 260  *
 261  * @str: Pointer to the string.
 262  *
 263  * Returns true if @str is a \ooo style octal value, false otherwise.
 264  *
 265  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
 266  * This function verifies that \ooo is in valid range.
 267  */
 268 static inline bool tomoyo_byte_range(const char *str)
 269 {
 270         return *str >= '0' && *str++ <= '3' &&
 271                 *str >= '0' && *str++ <= '7' &&
 272                 *str >= '0' && *str <= '7';
 273 }
 274
 275 /**
 276  * tomoyo_alphabet_char - Check whether the character is an alphabet.
 277  *
 278  * @c: The character to check.
 279  *
 280  * Returns true if @c is an alphabet character, false otherwise.
 281  */
 282 static inline bool tomoyo_alphabet_char(const char c)
 283 {
 284         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 285 }
 286
 287 /**
 288  * tomoyo_make_byte - Make byte value from three octal characters.
 289  *
 290  * @c1: The first character.
 291  * @c2: The second character.
 292  * @c3: The third character.
 293  *
 294  * Returns byte value.
 295  */
 296 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 297 {
 298         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 299 }
 300
 301 /**
 302  * tomoyo_valid - Check whether the character is a valid char.
 303  *
 304  * @c: The character to check.
 305  *
 306  * Returns true if @c is a valid character, false otherwise.
 307  */
 308 static inline bool tomoyo_valid(const unsigned char c)
 309 {
 310         return c > ' ' && c < 127;
 311 }
 312
 313 /**
 314  * tomoyo_invalid - Check whether the character is an invalid char.
 315  *
 316  * @c: The character to check.
 317  *
 318  * Returns true if @c is an invalid character, false otherwise.
 319  */
 320 static inline bool tomoyo_invalid(const unsigned char c)
 321 {
 322         return c && (c <= ' ' || c >= 127);
 323 }
 324
 325 /**
 326  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 327  *
 328  * @src:  Pointer to pointer to the string.
 329  * @find: Pointer to the keyword.
 330  *
 331  * Returns true if @src starts with @find, false otherwise.
 332  *
 333  * The @src is updated to point the first character after the @find
 334  * if @src starts with @find.
 335  */
 336 bool tomoyo_str_starts(char **src, const char *find)
 337 {
 338         const int len = strlen(find);
 339         char *tmp = *src;
 340
 341         if (strncmp(tmp, find, len))
 342                 return false;
 343         tmp += len;
 344         *src = tmp;
 345         return true;
 346 }
 347
 348 /**
 349  * tomoyo_normalize_line - Format string.
 350  *
 351  * @buffer: The line to normalize.
 352  *
 353  * Leading and trailing whitespaces are removed.
 354  * Multiple whitespaces are packed into single space.
 355  *
 356  * Returns nothing.
 357  */
 358 void tomoyo_normalize_line(unsigned char *buffer)
 359 {
 360         unsigned char *sp = buffer;
 361         unsigned char *dp = buffer;
 362         bool first = true;
 363
 364         while (tomoyo_invalid(*sp))
 365                 sp++;
 366         while (*sp) {
 367                 if (!first)
 368                         *dp++ = ' ';
 369                 first = false;
 370                 while (tomoyo_valid(*sp))
 371                         *dp++ = *sp++;
 372                 while (tomoyo_invalid(*sp))
 373                         sp++;
 374         }
 375         *dp = '\0';
 376 }
 377
 378 /**
 379  * tomoyo_correct_word2 - Validate a string.
 380  *
 381  * @string: The string to check. May be non-'\0'-terminated.
 382  * @len:    Length of @string.
 383  *
 384  * Check whether the given string follows the naming rules.
 385  * Returns true if @string follows the naming rules, false otherwise.
 386  */
 387 static bool tomoyo_correct_word2(const char *string, size_t len)
 388 {
 389         const char *const start = string;
 390         bool in_repetition = false;
 391         unsigned char c;
 392         unsigned char d;
 393         unsigned char e;
 394         if (!len)
 395                 goto out;
 396         while (len--) {
 397                 c = *string++;
 398                 if (c == '\\') {
 399                         if (!len--)
 400                                 goto out;
 401                         c = *string++;
 402                         switch (c) {
 403                         case '\\':  /* "\\" */
 404                                 continue;
 405                         case '$':   /* "\$" */
 406                         case '+':   /* "\+" */
 407                         case '?':   /* "\?" */
 408                         case '*':   /* "\*" */
 409                         case '@':   /* "\@" */
 410                         case 'x':   /* "\x" */
 411                         case 'X':   /* "\X" */
 412                         case 'a':   /* "\a" */
 413                         case 'A':   /* "\A" */
 414                         case '-':   /* "\-" */
 415                                 continue;
 416                         case '{':   /* "/\{" */
 417                                 if (string - 3 < start || *(string - 3) != '/')
 418                                         break;
 419                                 in_repetition = true;
 420                                 continue;
 421                         case '}':   /* "\}/" */
 422                                 if (*string != '/')
 423                                         break;
 424                                 if (!in_repetition)
 425                                         break;
 426                                 in_repetition = false;
 427                                 continue;
 428                         case '0':   /* "\ooo" */
 429                         case '1':
 430                         case '2':
 431                         case '3':
 432                                 if (!len-- || !len--)
 433                                         break;
 434                                 d = *string++;
 435                                 e = *string++;
 436                                 if (d < '0' || d > '7' || e < '0' || e > '7')
 437                                         break;
 438                                 c = tomoyo_make_byte(c, d, e);
 439                                 if (tomoyo_invalid(c))
 440                                         continue; /* pattern is not \000 */
 441                         }
 442                         goto out;
 443                 } else if (in_repetition && c == '/') {
 444                         goto out;
 445                 } else if (tomoyo_invalid(c)) {
 446                         goto out;
 447                 }
 448         }
 449         if (in_repetition)
 450                 goto out;
 451         return true;
 452  out:
 453         return false;
 454 }
 455
 456 /**
 457  * tomoyo_correct_word - Validate a string.
 458  *
 459  * @string: The string to check.
 460  *
 461  * Check whether the given string follows the naming rules.
 462  * Returns true if @string follows the naming rules, false otherwise.
 463  */
 464 bool tomoyo_correct_word(const char *string)
 465 {
 466         return tomoyo_correct_word2(string, strlen(string));
 467 }
 468
 469 /**
 470  * tomoyo_correct_path - Validate a pathname.
 471  *
 472  * @filename: The pathname to check.
 473  *
 474  * Check whether the given pathname follows the naming rules.
 475  * Returns true if @filename follows the naming rules, false otherwise.
 476  */
 477 bool tomoyo_correct_path(const char *filename)
 478 {
 479         return *filename == '/' && tomoyo_correct_word(filename);
 480 }
 481
 482 /**
 483  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
 484  *
 485  * @domainname: The domainname to check.
 486  *
 487  * Returns true if @domainname follows the naming rules, false otherwise.
 488  */
 489 bool tomoyo_correct_domain(const unsigned char *domainname)
 490 {
 491         if (!domainname || !tomoyo_domain_def(domainname))
 492                 return false;
 493         domainname = strchr(domainname, ' ');
 494         if (!domainname++)
 495                 return true;
 496         while (1) {
 497                 const unsigned char *cp = strchr(domainname, ' ');
 498                 if (!cp)
 499                         break;
 500                 if (*domainname != '/' ||
 501                     !tomoyo_correct_word2(domainname, cp - domainname))
 502                         return false;
 503                 domainname = cp + 1;
 504         }
 505         return tomoyo_correct_path(domainname);
 506 }
 507
 508 /**
 509  * tomoyo_domain_def - Check whether the given token can be a domainname.
 510  *
 511  * @buffer: The token to check.
 512  *
 513  * Returns true if @buffer possibly be a domainname, false otherwise.
 514  */
 515 bool tomoyo_domain_def(const unsigned char *buffer)
 516 {
 517         const unsigned char *cp;
 518         int len;
 519         if (*buffer != '<')
 520                 return false;
 521         cp = strchr(buffer, ' ');
 522         if (!cp)
 523                 len = strlen(buffer);
 524         else
 525                 len = cp - buffer;
 526         if (buffer[len - 1] != '>' ||
 527             !tomoyo_correct_word2(buffer + 1, len - 2))
 528                 return false;
 529         return true;
 530 }
 531
 532 /**
 533  * tomoyo_find_domain - Find a domain by the given name.
 534  *
 535  * @domainname: The domainname to find.
 536  *
 537  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 538  *
 539  * Caller holds tomoyo_read_lock().
 540  */
 541 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 542 {
 543         struct tomoyo_domain_info *domain;
 544         struct tomoyo_path_info name;
 545
 546         name.name = domainname;
 547         tomoyo_fill_path_info(&name);
 548         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 549                 if (!domain->is_deleted &&
 550                     !tomoyo_pathcmp(&name, domain->domainname))
 551                         return domain;
 552         }
 553         return NULL;
 554 }
 555
 556 /**
 557  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 558  *
 559  * @filename: The string to evaluate.
 560  *
 561  * Returns the initial length without a pattern in @filename.
 562  */
 563 static int tomoyo_const_part_length(const char *filename)
 564 {
 565         char c;
 566         int len = 0;
 567
 568         if (!filename)
 569                 return 0;
 570         while ((c = *filename++) != '\0') {
 571                 if (c != '\\') {
 572                         len++;
 573                         continue;
 574                 }
 575                 c = *filename++;
 576                 switch (c) {
 577                 case '\\':  /* "\\" */
 578                         len += 2;
 579                         continue;
 580                 case '0':   /* "\ooo" */
 581                 case '1':
 582                 case '2':
 583                 case '3':
 584                         c = *filename++;
 585                         if (c < '0' || c > '7')
 586                                 break;
 587                         c = *filename++;
 588                         if (c < '0' || c > '7')
 589                                 break;
 590                         len += 4;
 591                         continue;
 592                 }
 593                 break;
 594         }
 595         return len;
 596 }
 597
 598 /**
 599  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 600  *
 601  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 602  *
 603  * The caller sets "struct tomoyo_path_info"->name.
 604  */
 605 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 606 {
 607         const char *name = ptr->name;
 608         const int len = strlen(name);
 609
 610         ptr->const_len = tomoyo_const_part_length(name);
 611         ptr->is_dir = len && (name[len - 1] == '/');
 612         ptr->is_patterned = (ptr->const_len < len);
 613         ptr->hash = full_name_hash(name, len);
 614 }
 615
 616 /**
 617  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
 618  *
 619  * @filename:     The start of string to check.
 620  * @filename_end: The end of string to check.
 621  * @pattern:      The start of pattern to compare.
 622  * @pattern_end:  The end of pattern to compare.
 623  *
 624  * Returns true if @filename matches @pattern, false otherwise.
 625  */
 626 static bool tomoyo_file_matches_pattern2(const char *filename,
 627                                          const char *filename_end,
 628                                          const char *pattern,
 629                                          const char *pattern_end)
 630 {
 631         while (filename < filename_end && pattern < pattern_end) {
 632                 char c;
 633                 if (*pattern != '\\') {
 634                         if (*filename++ != *pattern++)
 635                                 return false;
 636                         continue;
 637                 }
 638                 c = *filename;
 639                 pattern++;
 640                 switch (*pattern) {
 641                         int i;
 642                         int j;
 643                 case '?':
 644                         if (c == '/') {
 645                                 return false;
 646                         } else if (c == '\\') {
 647                                 if (filename[1] == '\\')
 648                                         filename++;
 649                                 else if (tomoyo_byte_range(filename + 1))
 650                                         filename += 3;
 651                                 else
 652                                         return false;
 653                         }
 654                         break;
 655                 case '\\':
 656                         if (c != '\\')
 657                                 return false;
 658                         if (*++filename != '\\')
 659                                 return false;
 660                         break;
 661                 case '+':
 662                         if (!isdigit(c))
 663                                 return false;
 664                         break;
 665                 case 'x':
 666                         if (!isxdigit(c))
 667                                 return false;
 668                         break;
 669                 case 'a':
 670                         if (!tomoyo_alphabet_char(c))
 671                                 return false;
 672                         break;
 673                 case '0':
 674                 case '1':
 675                 case '2':
 676                 case '3':
 677                         if (c == '\\' && tomoyo_byte_range(filename + 1)
 678                             && strncmp(filename + 1, pattern, 3) == 0) {
 679                                 filename += 3;
 680                                 pattern += 2;
 681                                 break;
 682                         }
 683                         return false; /* Not matched. */
 684                 case '*':
 685                 case '@':
 686                         for (i = 0; i <= filename_end - filename; i++) {
 687                                 if (tomoyo_file_matches_pattern2(
 688                                                     filename + i, filename_end,
 689                                                     pattern + 1, pattern_end))
 690                                         return true;
 691                                 c = filename[i];
 692                                 if (c == '.' && *pattern == '@')
 693                                         break;
 694                                 if (c != '\\')
 695                                         continue;
 696                                 if (filename[i + 1] == '\\')
 697                                         i++;
 698                                 else if (tomoyo_byte_range(filename + i + 1))
 699                                         i += 3;
 700                                 else
 701                                         break; /* Bad pattern. */
 702                         }
 703                         return false; /* Not matched. */
 704                 default:
 705                         j = 0;
 706                         c = *pattern;
 707                         if (c == '$') {
 708                                 while (isdigit(filename[j]))
 709                                         j++;
 710                         } else if (c == 'X') {
 711                                 while (isxdigit(filename[j]))
 712                                         j++;
 713                         } else if (c == 'A') {
 714                                 while (tomoyo_alphabet_char(filename[j]))
 715                                         j++;
 716                         }
 717                         for (i = 1; i <= j; i++) {
 718                                 if (tomoyo_file_matches_pattern2(
 719                                                     filename + i, filename_end,
 720                                                     pattern + 1, pattern_end))
 721                                         return true;
 722                         }
 723                         return false; /* Not matched or bad pattern. */
 724                 }
 725                 filename++;
 726                 pattern++;
 727         }
 728         while (*pattern == '\\' &&
 729                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 730                 pattern += 2;
 731         return filename == filename_end && pattern == pattern_end;
 732 }
 733
 734 /**
 735  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
 736  *
 737  * @filename:     The start of string to check.
 738  * @filename_end: The end of string to check.
 739  * @pattern:      The start of pattern to compare.
 740  * @pattern_end:  The end of pattern to compare.
 741  *
 742  * Returns true if @filename matches @pattern, false otherwise.
 743  */
 744 static bool tomoyo_file_matches_pattern(const char *filename,
 745                                         const char *filename_end,
 746                                         const char *pattern,
 747                                         const char *pattern_end)
 748 {
 749         const char *pattern_start = pattern;
 750         bool first = true;
 751         bool result;
 752
 753         while (pattern < pattern_end - 1) {
 754                 /* Split at "\-" pattern. */
 755                 if (*pattern++ != '\\' || *pattern++ != '-')
 756                         continue;
 757                 result = tomoyo_file_matches_pattern2(filename,
 758                                                       filename_end,
 759                                                       pattern_start,
 760                                                       pattern - 2);
 761                 if (first)
 762                         result = !result;
 763                 if (result)
 764                         return false;
 765                 first = false;
 766                 pattern_start = pattern;
 767         }
 768         result = tomoyo_file_matches_pattern2(filename, filename_end,
 769                                               pattern_start, pattern_end);
 770         return first ? result : !result;
 771 }
 772
 773 /**
 774  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 775  *
 776  * @f: The start of string to check.
 777  * @p: The start of pattern to compare.
 778  *
 779  * Returns true if @f matches @p, false otherwise.
 780  */
 781 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 782 {
 783         const char *f_delimiter;
 784         const char *p_delimiter;
 785
 786         while (*f && *p) {
 787                 f_delimiter = strchr(f, '/');
 788                 if (!f_delimiter)
 789                         f_delimiter = f + strlen(f);
 790                 p_delimiter = strchr(p, '/');
 791                 if (!p_delimiter)
 792                         p_delimiter = p + strlen(p);
 793                 if (*p == '\\' && *(p + 1) == '{')
 794                         goto recursive;
 795                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 796                                                  p_delimiter))
 797                         return false;
 798                 f = f_delimiter;
 799                 if (*f)
 800                         f++;
 801                 p = p_delimiter;
 802                 if (*p)
 803                         p++;
 804         }
 805         /* Ignore trailing "\*" and "\@" in @pattern. */
 806         while (*p == '\\' &&
 807                (*(p + 1) == '*' || *(p + 1) == '@'))
 808                 p += 2;
 809         return !*f && !*p;
 810  recursive:
 811         /*
 812          * The "\{" pattern is permitted only after '/' character.
 813          * This guarantees that below "*(p - 1)" is safe.
 814          * Also, the "\}" pattern is permitted only before '/' character
 815          * so that "\{" + "\}" pair will not break the "\-" operator.
 816          */
 817         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 818             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 819                 return false; /* Bad pattern. */
 820         do {
 821                 /* Compare current component with pattern. */
 822                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 823                                                  p_delimiter - 2))
 824                         break;
 825                 /* Proceed to next component. */
 826                 f = f_delimiter;
 827                 if (!*f)
 828                         break;
 829                 f++;
 830                 /* Continue comparison. */
 831                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 832                         return true;
 833                 f_delimiter = strchr(f, '/');
 834         } while (f_delimiter);
 835         return false; /* Not matched. */
 836 }
 837
 838 /**
 839  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 840  *
 841  * @filename: The filename to check.
 842  * @pattern:  The pattern to compare.
 843  *
 844  * Returns true if matches, false otherwise.
 845  *
 846  * The following patterns are available.
 847  *   \\     \ itself.
 848  *   \ooo   Octal representation of a byte.
 849  *   \*     Zero or more repetitions of characters other than '/'.
 850  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 851  *   \?     1 byte character other than '/'.
 852  *   \$     One or more repetitions of decimal digits.
 853  *   \+     1 decimal digit.
 854  *   \X     One or more repetitions of hexadecimal digits.
 855  *   \x     1 hexadecimal digit.
 856  *   \A     One or more repetitions of alphabet characters.
 857  *   \a     1 alphabet character.
 858  *
 859  *   \-     Subtraction operator.
 860  *
 861  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 862  *               /dir/dir/dir/ ).
 863  */
 864 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 865                                  const struct tomoyo_path_info *pattern)
 866 {
 867         const char *f = filename->name;
 868         const char *p = pattern->name;
 869         const int len = pattern->const_len;
 870
 871         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 872         if (!pattern->is_patterned)
 873                 return !tomoyo_pathcmp(filename, pattern);
 874         /* Don't compare directory and non-directory. */
 875         if (filename->is_dir != pattern->is_dir)
 876                 return false;
 877         /* Compare the initial length without patterns. */
 878         if (strncmp(f, p, len))
 879                 return false;
 880         f += len;
 881         p += len;
 882         return tomoyo_path_matches_pattern2(f, p);
 883 }
 884
 885 /**
 886  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 887  *
 888  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 889  *
 890  * This function uses kzalloc(), so the caller must call kfree()
 891  * if this function didn't return NULL.
 892  */
 893 const char *tomoyo_get_exe(void)
 894 {
 895         struct mm_struct *mm = current->mm;
 896         struct vm_area_struct *vma;
 897         const char *cp = NULL;
 898
 899         if (!mm)
 900                 return NULL;
 901         down_read(&mm->mmap_sem);
 902         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 903                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 904                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 905                         break;
 906                 }
 907         }
 908         up_read(&mm->mmap_sem);
 909         return cp;
 910 }
 911
 912 /**
 913  * tomoyo_get_mode - Get MAC mode.
 914  *
 915  * @ns:      Pointer to "struct tomoyo_policy_namespace".
 916  * @profile: Profile number.
 917  * @index:   Index number of functionality.
 918  *
 919  * Returns mode.
 920  */
 921 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
 922                     const u8 index)
 923 {
 924         u8 mode;
 925         const u8 category = TOMOYO_MAC_CATEGORY_FILE;
 926         if (!tomoyo_policy_loaded)
 927                 return TOMOYO_CONFIG_DISABLED;
 928         mode = tomoyo_profile(ns, profile)->config[index];
 929         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
 930                 mode = tomoyo_profile(ns, profile)->config[category];
 931         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
 932                 mode = tomoyo_profile(ns, profile)->default_config;
 933         return mode & 3;
 934 }
 935
 936 /**
 937  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
 938  *
 939  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
 940  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
 941  * @index:  Index number of functionality.
 942  *
 943  * Returns mode.
 944  */
 945 int tomoyo_init_request_info(struct tomoyo_request_info *r,
 946                              struct tomoyo_domain_info *domain, const u8 index)
 947 {
 948         u8 profile;
 949         memset(r, 0, sizeof(*r));
 950         if (!domain)
 951                 domain = tomoyo_domain();
 952         r->domain = domain;
 953         profile = domain->profile;
 954         r->profile = profile;
 955         r->type = index;
 956         r->mode = tomoyo_get_mode(domain->ns, profile, index);
 957         return r->mode;
 958 }
 959
 960 /**
 961  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 962  *
 963  * @r: Pointer to "struct tomoyo_request_info".
 964  *
 965  * Returns true if the domain is not exceeded quota, false otherwise.
 966  *
 967  * Caller holds tomoyo_read_lock().
 968  */
 969 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
 970 {
 971         unsigned int count = 0;
 972         struct tomoyo_domain_info *domain = r->domain;
 973         struct tomoyo_acl_info *ptr;
 974
 975         if (r->mode != TOMOYO_CONFIG_LEARNING)
 976                 return false;
 977         if (!domain)
 978                 return true;
 979         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 980                 u16 perm;
 981                 u8 i;
 982                 if (ptr->is_deleted)
 983                         continue;
 984                 switch (ptr->type) {
 985                 case TOMOYO_TYPE_PATH_ACL:
 986                         perm = container_of(ptr, struct tomoyo_path_acl, head)
 987                                 ->perm;
 988                         break;
 989                 case TOMOYO_TYPE_PATH2_ACL:
 990                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
 991                                 ->perm;
 992                         break;
 993                 case TOMOYO_TYPE_PATH_NUMBER_ACL:
 994                         perm = container_of(ptr, struct tomoyo_path_number_acl,
 995                                             head)->perm;
 996                         break;
 997                 case TOMOYO_TYPE_MKDEV_ACL:
 998                         perm = container_of(ptr, struct tomoyo_mkdev_acl,
 999                                             head)->perm;
1000                         break;
1001                 default:
1002                         perm = 1;
1003                 }
1004                 for (i = 0; i < 16; i++)
1005                         if (perm & (1 << i))
1006                                 count++;
1007         }
1008         if (count < tomoyo_profile(domain->ns, domain->profile)->
1009             pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1010                 return true;
1011         if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1012                 domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1013                 /* r->granted = false; */
1014                 tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1015                 printk(KERN_WARNING "WARNING: "
1016                        "Domain '%s' has too many ACLs to hold. "
1017                        "Stopped learning mode.\n", domain->domainname->name);
1018         }
1019         return false;
1020 }