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  * tomoyo_parse_ulong - Parse an "unsigned long" value.
  20  *
  21  * @result: Pointer to "unsigned long".
  22  * @str:    Pointer to string to parse.
  23  *
  24  * Returns value type on success, 0 otherwise.
  25  *
  26  * The @src is updated to point the first character after the value
  27  * on success.
  28  */
  29 static u8 tomoyo_parse_ulong(unsigned long *result, char **str)
  30 {
  31         const char *cp = *str;
  32         char *ep;
  33         int base = 10;
  34         if (*cp == '0') {
  35                 char c = *(cp + 1);
  36                 if (c == 'x' || c == 'X') {
  37                         base = 16;
  38                         cp += 2;
  39                 } else if (c >= '0' && c <= '7') {
  40                         base = 8;
  41                         cp++;
  42                 }
  43         }
  44         *result = simple_strtoul(cp, &ep, base);
  45         if (cp == ep)
  46                 return 0;
  47         *str = ep;
  48         switch (base) {
  49         case 16:
  50                 return TOMOYO_VALUE_TYPE_HEXADECIMAL;
  51         case 8:
  52                 return TOMOYO_VALUE_TYPE_OCTAL;
  53         default:
  54                 return TOMOYO_VALUE_TYPE_DECIMAL;
  55         }
  56 }
  57
  58 /**
  59  * tomoyo_print_ulong - Print an "unsigned long" value.
  60  *
  61  * @buffer:     Pointer to buffer.
  62  * @buffer_len: Size of @buffer.
  63  * @value:      An "unsigned long" value.
  64  * @type:       Type of @value.
  65  *
  66  * Returns nothing.
  67  */
  68 void tomoyo_print_ulong(char *buffer, const int buffer_len,
  69                         const unsigned long value, const u8 type)
  70 {
  71         if (type == TOMOYO_VALUE_TYPE_DECIMAL)
  72                 snprintf(buffer, buffer_len, "%lu", value);
  73         else if (type == TOMOYO_VALUE_TYPE_OCTAL)
  74                 snprintf(buffer, buffer_len, "0%lo", value);
  75         else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
  76                 snprintf(buffer, buffer_len, "0x%lX", value);
  77         else
  78                 snprintf(buffer, buffer_len, "type(%u)", type);
  79 }
  80
  81 /**
  82  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
  83  *
  84  * @filename: Name or name group.
  85  * @ptr:      Pointer to "struct tomoyo_name_union".
  86  *
  87  * Returns true on success, false otherwise.
  88  */
  89 bool tomoyo_parse_name_union(const char *filename,
  90                              struct tomoyo_name_union *ptr)
  91 {
  92         if (!tomoyo_correct_word(filename))
  93                 return false;
  94         if (filename[0] == '@') {
  95                 ptr->group = tomoyo_get_group(filename + 1, TOMOYO_PATH_GROUP);
  96                 ptr->is_group = true;
  97                 return ptr->group != NULL;
  98         }
  99         ptr->filename = tomoyo_get_name(filename);
 100         ptr->is_group = false;
 101         return ptr->filename != NULL;
 102 }
 103
 104 /**
 105  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
 106  *
 107  * @data: Number or number range or number group.
 108  * @ptr:  Pointer to "struct tomoyo_number_union".
 109  *
 110  * Returns true on success, false otherwise.
 111  */
 112 bool tomoyo_parse_number_union(char *data, struct tomoyo_number_union *num)
 113 {
 114         u8 type;
 115         unsigned long v;
 116         memset(num, 0, sizeof(*num));
 117         if (data[0] == '@') {
 118                 if (!tomoyo_correct_word(data))
 119                         return false;
 120                 num->group = tomoyo_get_group(data + 1, TOMOYO_NUMBER_GROUP);
 121                 num->is_group = true;
 122                 return num->group != NULL;
 123         }
 124         type = tomoyo_parse_ulong(&v, &data);
 125         if (!type)
 126                 return false;
 127         num->values[0] = v;
 128         num->min_type = type;
 129         if (!*data) {
 130                 num->values[1] = v;
 131                 num->max_type = type;
 132                 return true;
 133         }
 134         if (*data++ != '-')
 135                 return false;
 136         type = tomoyo_parse_ulong(&v, &data);
 137         if (!type || *data)
 138                 return false;
 139         num->values[1] = v;
 140         num->max_type = type;
 141         return true;
 142 }
 143
 144 /**
 145  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
 146  *
 147  * @str: Pointer to the string.
 148  *
 149  * Returns true if @str is a \ooo style octal value, false otherwise.
 150  *
 151  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
 152  * This function verifies that \ooo is in valid range.
 153  */
 154 static inline bool tomoyo_byte_range(const char *str)
 155 {
 156         return *str >= '0' && *str++ <= '3' &&
 157                 *str >= '0' && *str++ <= '7' &&
 158                 *str >= '0' && *str <= '7';
 159 }
 160
 161 /**
 162  * tomoyo_alphabet_char - Check whether the character is an alphabet.
 163  *
 164  * @c: The character to check.
 165  *
 166  * Returns true if @c is an alphabet character, false otherwise.
 167  */
 168 static inline bool tomoyo_alphabet_char(const char c)
 169 {
 170         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 171 }
 172
 173 /**
 174  * tomoyo_make_byte - Make byte value from three octal characters.
 175  *
 176  * @c1: The first character.
 177  * @c2: The second character.
 178  * @c3: The third character.
 179  *
 180  * Returns byte value.
 181  */
 182 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 183 {
 184         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 185 }
 186
 187 /**
 188  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 189  *
 190  * @src:  Pointer to pointer to the string.
 191  * @find: Pointer to the keyword.
 192  *
 193  * Returns true if @src starts with @find, false otherwise.
 194  *
 195  * The @src is updated to point the first character after the @find
 196  * if @src starts with @find.
 197  */
 198 bool tomoyo_str_starts(char **src, const char *find)
 199 {
 200         const int len = strlen(find);
 201         char *tmp = *src;
 202
 203         if (strncmp(tmp, find, len))
 204                 return false;
 205         tmp += len;
 206         *src = tmp;
 207         return true;
 208 }
 209
 210 /**
 211  * tomoyo_normalize_line - Format string.
 212  *
 213  * @buffer: The line to normalize.
 214  *
 215  * Leading and trailing whitespaces are removed.
 216  * Multiple whitespaces are packed into single space.
 217  *
 218  * Returns nothing.
 219  */
 220 void tomoyo_normalize_line(unsigned char *buffer)
 221 {
 222         unsigned char *sp = buffer;
 223         unsigned char *dp = buffer;
 224         bool first = true;
 225
 226         while (tomoyo_invalid(*sp))
 227                 sp++;
 228         while (*sp) {
 229                 if (!first)
 230                         *dp++ = ' ';
 231                 first = false;
 232                 while (tomoyo_valid(*sp))
 233                         *dp++ = *sp++;
 234                 while (tomoyo_invalid(*sp))
 235                         sp++;
 236         }
 237         *dp = '\0';
 238 }
 239
 240 /**
 241  * tomoyo_tokenize - Tokenize string.
 242  *
 243  * @buffer: The line to tokenize.
 244  * @w:      Pointer to "char *".
 245  * @size:   Sizeof @w .
 246  *
 247  * Returns true on success, false otherwise.
 248  */
 249 bool tomoyo_tokenize(char *buffer, char *w[], size_t size)
 250 {
 251         int count = size / sizeof(char *);
 252         int i;
 253         for (i = 0; i < count; i++)
 254                 w[i] = "";
 255         for (i = 0; i < count; i++) {
 256                 char *cp = strchr(buffer, ' ');
 257                 if (cp)
 258                         *cp = '\0';
 259                 w[i] = buffer;
 260                 if (!cp)
 261                         break;
 262                 buffer = cp + 1;
 263         }
 264         return i < count || !*buffer;
 265 }
 266
 267 /**
 268  * tomoyo_correct_word2 - Validate a string.
 269  *
 270  * @string: The string to check. May be non-'\0'-terminated.
 271  * @len:    Length of @string.
 272  *
 273  * Check whether the given string follows the naming rules.
 274  * Returns true if @string follows the naming rules, false otherwise.
 275  */
 276 static bool tomoyo_correct_word2(const char *string, size_t len)
 277 {
 278         const char *const start = string;
 279         bool in_repetition = false;
 280         unsigned char c;
 281         unsigned char d;
 282         unsigned char e;
 283         if (!len)
 284                 goto out;
 285         while (len--) {
 286                 c = *string++;
 287                 if (c == '\\') {
 288                         if (!len--)
 289                                 goto out;
 290                         c = *string++;
 291                         switch (c) {
 292                         case '\\':  /* "\\" */
 293                                 continue;
 294                         case '$':   /* "\$" */
 295                         case '+':   /* "\+" */
 296                         case '?':   /* "\?" */
 297                         case '*':   /* "\*" */
 298                         case '@':   /* "\@" */
 299                         case 'x':   /* "\x" */
 300                         case 'X':   /* "\X" */
 301                         case 'a':   /* "\a" */
 302                         case 'A':   /* "\A" */
 303                         case '-':   /* "\-" */
 304                                 continue;
 305                         case '{':   /* "/\{" */
 306                                 if (string - 3 < start || *(string - 3) != '/')
 307                                         break;
 308                                 in_repetition = true;
 309                                 continue;
 310                         case '}':   /* "\}/" */
 311                                 if (*string != '/')
 312                                         break;
 313                                 if (!in_repetition)
 314                                         break;
 315                                 in_repetition = false;
 316                                 continue;
 317                         case '0':   /* "\ooo" */
 318                         case '1':
 319                         case '2':
 320                         case '3':
 321                                 if (!len-- || !len--)
 322                                         break;
 323                                 d = *string++;
 324                                 e = *string++;
 325                                 if (d < '0' || d > '7' || e < '0' || e > '7')
 326                                         break;
 327                                 c = tomoyo_make_byte(c, d, e);
 328                                 if (tomoyo_invalid(c))
 329                                         continue; /* pattern is not \000 */
 330                         }
 331                         goto out;
 332                 } else if (in_repetition && c == '/') {
 333                         goto out;
 334                 } else if (tomoyo_invalid(c)) {
 335                         goto out;
 336                 }
 337         }
 338         if (in_repetition)
 339                 goto out;
 340         return true;
 341  out:
 342         return false;
 343 }
 344
 345 /**
 346  * tomoyo_correct_word - Validate a string.
 347  *
 348  * @string: The string to check.
 349  *
 350  * Check whether the given string follows the naming rules.
 351  * Returns true if @string follows the naming rules, false otherwise.
 352  */
 353 bool tomoyo_correct_word(const char *string)
 354 {
 355         return tomoyo_correct_word2(string, strlen(string));
 356 }
 357
 358 /**
 359  * tomoyo_correct_path - Validate a pathname.
 360  *
 361  * @filename: The pathname to check.
 362  *
 363  * Check whether the given pathname follows the naming rules.
 364  * Returns true if @filename follows the naming rules, false otherwise.
 365  */
 366 bool tomoyo_correct_path(const char *filename)
 367 {
 368         return *filename == '/' && tomoyo_correct_word(filename);
 369 }
 370
 371 /**
 372  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
 373  *
 374  * @domainname: The domainname to check.
 375  *
 376  * Returns true if @domainname follows the naming rules, false otherwise.
 377  */
 378 bool tomoyo_correct_domain(const unsigned char *domainname)
 379 {
 380         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 381                                    TOMOYO_ROOT_NAME_LEN))
 382                 goto out;
 383         domainname += TOMOYO_ROOT_NAME_LEN;
 384         if (!*domainname)
 385                 return true;
 386         if (*domainname++ != ' ')
 387                 goto out;
 388         while (1) {
 389                 const unsigned char *cp = strchr(domainname, ' ');
 390                 if (!cp)
 391                         break;
 392                 if (*domainname != '/' ||
 393                     !tomoyo_correct_word2(domainname, cp - domainname))
 394                         goto out;
 395                 domainname = cp + 1;
 396         }
 397         return tomoyo_correct_path(domainname);
 398  out:
 399         return false;
 400 }
 401
 402 /**
 403  * tomoyo_domain_def - Check whether the given token can be a domainname.
 404  *
 405  * @buffer: The token to check.
 406  *
 407  * Returns true if @buffer possibly be a domainname, false otherwise.
 408  */
 409 bool tomoyo_domain_def(const unsigned char *buffer)
 410 {
 411         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 412 }
 413
 414 /**
 415  * tomoyo_find_domain - Find a domain by the given name.
 416  *
 417  * @domainname: The domainname to find.
 418  *
 419  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 420  *
 421  * Caller holds tomoyo_read_lock().
 422  */
 423 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 424 {
 425         struct tomoyo_domain_info *domain;
 426         struct tomoyo_path_info name;
 427
 428         name.name = domainname;
 429         tomoyo_fill_path_info(&name);
 430         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 431                 if (!domain->is_deleted &&
 432                     !tomoyo_pathcmp(&name, domain->domainname))
 433                         return domain;
 434         }
 435         return NULL;
 436 }
 437
 438 /**
 439  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 440  *
 441  * @filename: The string to evaluate.
 442  *
 443  * Returns the initial length without a pattern in @filename.
 444  */
 445 static int tomoyo_const_part_length(const char *filename)
 446 {
 447         char c;
 448         int len = 0;
 449
 450         if (!filename)
 451                 return 0;
 452         while ((c = *filename++) != '\0') {
 453                 if (c != '\\') {
 454                         len++;
 455                         continue;
 456                 }
 457                 c = *filename++;
 458                 switch (c) {
 459                 case '\\':  /* "\\" */
 460                         len += 2;
 461                         continue;
 462                 case '0':   /* "\ooo" */
 463                 case '1':
 464                 case '2':
 465                 case '3':
 466                         c = *filename++;
 467                         if (c < '0' || c > '7')
 468                                 break;
 469                         c = *filename++;
 470                         if (c < '0' || c > '7')
 471                                 break;
 472                         len += 4;
 473                         continue;
 474                 }
 475                 break;
 476         }
 477         return len;
 478 }
 479
 480 /**
 481  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 482  *
 483  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 484  *
 485  * The caller sets "struct tomoyo_path_info"->name.
 486  */
 487 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 488 {
 489         const char *name = ptr->name;
 490         const int len = strlen(name);
 491
 492         ptr->const_len = tomoyo_const_part_length(name);
 493         ptr->is_dir = len && (name[len - 1] == '/');
 494         ptr->is_patterned = (ptr->const_len < len);
 495         ptr->hash = full_name_hash(name, len);
 496 }
 497
 498 /**
 499  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
 500  *
 501  * @filename:     The start of string to check.
 502  * @filename_end: The end of string to check.
 503  * @pattern:      The start of pattern to compare.
 504  * @pattern_end:  The end of pattern to compare.
 505  *
 506  * Returns true if @filename matches @pattern, false otherwise.
 507  */
 508 static bool tomoyo_file_matches_pattern2(const char *filename,
 509                                          const char *filename_end,
 510                                          const char *pattern,
 511                                          const char *pattern_end)
 512 {
 513         while (filename < filename_end && pattern < pattern_end) {
 514                 char c;
 515                 if (*pattern != '\\') {
 516                         if (*filename++ != *pattern++)
 517                                 return false;
 518                         continue;
 519                 }
 520                 c = *filename;
 521                 pattern++;
 522                 switch (*pattern) {
 523                         int i;
 524                         int j;
 525                 case '?':
 526                         if (c == '/') {
 527                                 return false;
 528                         } else if (c == '\\') {
 529                                 if (filename[1] == '\\')
 530                                         filename++;
 531                                 else if (tomoyo_byte_range(filename + 1))
 532                                         filename += 3;
 533                                 else
 534                                         return false;
 535                         }
 536                         break;
 537                 case '\\':
 538                         if (c != '\\')
 539                                 return false;
 540                         if (*++filename != '\\')
 541                                 return false;
 542                         break;
 543                 case '+':
 544                         if (!isdigit(c))
 545                                 return false;
 546                         break;
 547                 case 'x':
 548                         if (!isxdigit(c))
 549                                 return false;
 550                         break;
 551                 case 'a':
 552                         if (!tomoyo_alphabet_char(c))
 553                                 return false;
 554                         break;
 555                 case '0':
 556                 case '1':
 557                 case '2':
 558                 case '3':
 559                         if (c == '\\' && tomoyo_byte_range(filename + 1)
 560                             && strncmp(filename + 1, pattern, 3) == 0) {
 561                                 filename += 3;
 562                                 pattern += 2;
 563                                 break;
 564                         }
 565                         return false; /* Not matched. */
 566                 case '*':
 567                 case '@':
 568                         for (i = 0; i <= filename_end - filename; i++) {
 569                                 if (tomoyo_file_matches_pattern2(
 570                                                     filename + i, filename_end,
 571                                                     pattern + 1, pattern_end))
 572                                         return true;
 573                                 c = filename[i];
 574                                 if (c == '.' && *pattern == '@')
 575                                         break;
 576                                 if (c != '\\')
 577                                         continue;
 578                                 if (filename[i + 1] == '\\')
 579                                         i++;
 580                                 else if (tomoyo_byte_range(filename + i + 1))
 581                                         i += 3;
 582                                 else
 583                                         break; /* Bad pattern. */
 584                         }
 585                         return false; /* Not matched. */
 586                 default:
 587                         j = 0;
 588                         c = *pattern;
 589                         if (c == '$') {
 590                                 while (isdigit(filename[j]))
 591                                         j++;
 592                         } else if (c == 'X') {
 593                                 while (isxdigit(filename[j]))
 594                                         j++;
 595                         } else if (c == 'A') {
 596                                 while (tomoyo_alphabet_char(filename[j]))
 597                                         j++;
 598                         }
 599                         for (i = 1; i <= j; i++) {
 600                                 if (tomoyo_file_matches_pattern2(
 601                                                     filename + i, filename_end,
 602                                                     pattern + 1, pattern_end))
 603                                         return true;
 604                         }
 605                         return false; /* Not matched or bad pattern. */
 606                 }
 607                 filename++;
 608                 pattern++;
 609         }
 610         while (*pattern == '\\' &&
 611                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 612                 pattern += 2;
 613         return filename == filename_end && pattern == pattern_end;
 614 }
 615
 616 /**
 617  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
 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_pattern(const char *filename,
 627                                         const char *filename_end,
 628                                         const char *pattern,
 629                                         const char *pattern_end)
 630 {
 631         const char *pattern_start = pattern;
 632         bool first = true;
 633         bool result;
 634
 635         while (pattern < pattern_end - 1) {
 636                 /* Split at "\-" pattern. */
 637                 if (*pattern++ != '\\' || *pattern++ != '-')
 638                         continue;
 639                 result = tomoyo_file_matches_pattern2(filename,
 640                                                       filename_end,
 641                                                       pattern_start,
 642                                                       pattern - 2);
 643                 if (first)
 644                         result = !result;
 645                 if (result)
 646                         return false;
 647                 first = false;
 648                 pattern_start = pattern;
 649         }
 650         result = tomoyo_file_matches_pattern2(filename, filename_end,
 651                                               pattern_start, pattern_end);
 652         return first ? result : !result;
 653 }
 654
 655 /**
 656  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 657  *
 658  * @f: The start of string to check.
 659  * @p: The start of pattern to compare.
 660  *
 661  * Returns true if @f matches @p, false otherwise.
 662  */
 663 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 664 {
 665         const char *f_delimiter;
 666         const char *p_delimiter;
 667
 668         while (*f && *p) {
 669                 f_delimiter = strchr(f, '/');
 670                 if (!f_delimiter)
 671                         f_delimiter = f + strlen(f);
 672                 p_delimiter = strchr(p, '/');
 673                 if (!p_delimiter)
 674                         p_delimiter = p + strlen(p);
 675                 if (*p == '\\' && *(p + 1) == '{')
 676                         goto recursive;
 677                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 678                                                  p_delimiter))
 679                         return false;
 680                 f = f_delimiter;
 681                 if (*f)
 682                         f++;
 683                 p = p_delimiter;
 684                 if (*p)
 685                         p++;
 686         }
 687         /* Ignore trailing "\*" and "\@" in @pattern. */
 688         while (*p == '\\' &&
 689                (*(p + 1) == '*' || *(p + 1) == '@'))
 690                 p += 2;
 691         return !*f && !*p;
 692  recursive:
 693         /*
 694          * The "\{" pattern is permitted only after '/' character.
 695          * This guarantees that below "*(p - 1)" is safe.
 696          * Also, the "\}" pattern is permitted only before '/' character
 697          * so that "\{" + "\}" pair will not break the "\-" operator.
 698          */
 699         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 700             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 701                 return false; /* Bad pattern. */
 702         do {
 703                 /* Compare current component with pattern. */
 704                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 705                                                  p_delimiter - 2))
 706                         break;
 707                 /* Proceed to next component. */
 708                 f = f_delimiter;
 709                 if (!*f)
 710                         break;
 711                 f++;
 712                 /* Continue comparison. */
 713                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 714                         return true;
 715                 f_delimiter = strchr(f, '/');
 716         } while (f_delimiter);
 717         return false; /* Not matched. */
 718 }
 719
 720 /**
 721  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 722  *
 723  * @filename: The filename to check.
 724  * @pattern:  The pattern to compare.
 725  *
 726  * Returns true if matches, false otherwise.
 727  *
 728  * The following patterns are available.
 729  *   \\     \ itself.
 730  *   \ooo   Octal representation of a byte.
 731  *   \*     Zero or more repetitions of characters other than '/'.
 732  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 733  *   \?     1 byte character other than '/'.
 734  *   \$     One or more repetitions of decimal digits.
 735  *   \+     1 decimal digit.
 736  *   \X     One or more repetitions of hexadecimal digits.
 737  *   \x     1 hexadecimal digit.
 738  *   \A     One or more repetitions of alphabet characters.
 739  *   \a     1 alphabet character.
 740  *
 741  *   \-     Subtraction operator.
 742  *
 743  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 744  *               /dir/dir/dir/ ).
 745  */
 746 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 747                                  const struct tomoyo_path_info *pattern)
 748 {
 749         const char *f = filename->name;
 750         const char *p = pattern->name;
 751         const int len = pattern->const_len;
 752
 753         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 754         if (!pattern->is_patterned)
 755                 return !tomoyo_pathcmp(filename, pattern);
 756         /* Don't compare directory and non-directory. */
 757         if (filename->is_dir != pattern->is_dir)
 758                 return false;
 759         /* Compare the initial length without patterns. */
 760         if (strncmp(f, p, len))
 761                 return false;
 762         f += len;
 763         p += len;
 764         return tomoyo_path_matches_pattern2(f, p);
 765 }
 766
 767 /**
 768  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 769  *
 770  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 771  *
 772  * This function uses kzalloc(), so the caller must call kfree()
 773  * if this function didn't return NULL.
 774  */
 775 const char *tomoyo_get_exe(void)
 776 {
 777         struct mm_struct *mm = current->mm;
 778         struct vm_area_struct *vma;
 779         const char *cp = NULL;
 780
 781         if (!mm)
 782                 return NULL;
 783         down_read(&mm->mmap_sem);
 784         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 785                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 786                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 787                         break;
 788                 }
 789         }
 790         up_read(&mm->mmap_sem);
 791         return cp;
 792 }
 793
 794 /**
 795  * tomoyo_get_mode - Get MAC mode.
 796  *
 797  * @profile: Profile number.
 798  * @index:   Index number of functionality.
 799  *
 800  * Returns mode.
 801  */
 802 int tomoyo_get_mode(const u8 profile, const u8 index)
 803 {
 804         u8 mode;
 805         const u8 category = TOMOYO_MAC_CATEGORY_FILE;
 806         if (!tomoyo_policy_loaded)
 807                 return TOMOYO_CONFIG_DISABLED;
 808         mode = tomoyo_profile(profile)->config[index];
 809         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
 810                 mode = tomoyo_profile(profile)->config[category];
 811         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
 812                 mode = tomoyo_profile(profile)->default_config;
 813         return mode & 3;
 814 }
 815
 816 /**
 817  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
 818  *
 819  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
 820  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
 821  * @index:  Index number of functionality.
 822  *
 823  * Returns mode.
 824  */
 825 int tomoyo_init_request_info(struct tomoyo_request_info *r,
 826                              struct tomoyo_domain_info *domain, const u8 index)
 827 {
 828         u8 profile;
 829         memset(r, 0, sizeof(*r));
 830         if (!domain)
 831                 domain = tomoyo_domain();
 832         r->domain = domain;
 833         profile = domain->profile;
 834         r->profile = profile;
 835         r->type = index;
 836         r->mode = tomoyo_get_mode(profile, index);
 837         return r->mode;
 838 }
 839
 840 /**
 841  * tomoyo_last_word - Get last component of a line.
 842  *
 843  * @line: A line.
 844  *
 845  * Returns the last word of a line.
 846  */
 847 const char *tomoyo_last_word(const char *name)
 848 {
 849         const char *cp = strrchr(name, ' ');
 850         if (cp)
 851                 return cp + 1;
 852         return name;
 853 }
 854
 855 /**
 856  * tomoyo_warn_log - Print warning or error message on console.
 857  *
 858  * @r:   Pointer to "struct tomoyo_request_info".
 859  * @fmt: The printf()'s format string, followed by parameters.
 860  */
 861 void tomoyo_warn_log(struct tomoyo_request_info *r, const char *fmt, ...)
 862 {
 863         va_list args;
 864         char *buffer;
 865         const struct tomoyo_domain_info * const domain = r->domain;
 866         const struct tomoyo_profile *profile = tomoyo_profile(domain->profile);
 867         switch (r->mode) {
 868         case TOMOYO_CONFIG_ENFORCING:
 869                 if (!profile->enforcing->enforcing_verbose)
 870                         return;
 871                 break;
 872         case TOMOYO_CONFIG_PERMISSIVE:
 873                 if (!profile->permissive->permissive_verbose)
 874                         return;
 875                 break;
 876         case TOMOYO_CONFIG_LEARNING:
 877                 if (!profile->learning->learning_verbose)
 878                         return;
 879                 break;
 880         }
 881         buffer = kmalloc(4096, GFP_NOFS);
 882         if (!buffer)
 883                 return;
 884         va_start(args, fmt);
 885         vsnprintf(buffer, 4095, fmt, args);
 886         va_end(args);
 887         buffer[4095] = '\0';
 888         printk(KERN_WARNING "%s: Access %s denied for %s\n",
 889                r->mode == TOMOYO_CONFIG_ENFORCING ? "ERROR" : "WARNING", buffer,
 890                tomoyo_last_word(domain->domainname->name));
 891         kfree(buffer);
 892 }
 893
 894 /**
 895  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 896  *
 897  * @r: Pointer to "struct tomoyo_request_info".
 898  *
 899  * Returns true if the domain is not exceeded quota, false otherwise.
 900  *
 901  * Caller holds tomoyo_read_lock().
 902  */
 903 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
 904 {
 905         unsigned int count = 0;
 906         struct tomoyo_domain_info *domain = r->domain;
 907         struct tomoyo_acl_info *ptr;
 908
 909         if (r->mode != TOMOYO_CONFIG_LEARNING)
 910                 return false;
 911         if (!domain)
 912                 return true;
 913         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 914                 if (ptr->is_deleted)
 915                         continue;
 916                 switch (ptr->type) {
 917                         u16 perm;
 918                         u8 i;
 919                 case TOMOYO_TYPE_PATH_ACL:
 920                         perm = container_of(ptr, struct tomoyo_path_acl, head)
 921                                 ->perm;
 922                         for (i = 0; i < TOMOYO_MAX_PATH_OPERATION; i++)
 923                                 if (perm & (1 << i))
 924                                         count++;
 925                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
 926                                 count -= 2;
 927                         break;
 928                 case TOMOYO_TYPE_PATH2_ACL:
 929                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
 930                                 ->perm;
 931                         for (i = 0; i < TOMOYO_MAX_PATH2_OPERATION; i++)
 932                                 if (perm & (1 << i))
 933                                         count++;
 934                         break;
 935                 case TOMOYO_TYPE_PATH_NUMBER_ACL:
 936                         perm = container_of(ptr, struct tomoyo_path_number_acl,
 937                                             head)->perm;
 938                         for (i = 0; i < TOMOYO_MAX_PATH_NUMBER_OPERATION; i++)
 939                                 if (perm & (1 << i))
 940                                         count++;
 941                         break;
 942                 case TOMOYO_TYPE_MKDEV_ACL:
 943                         perm = container_of(ptr, struct tomoyo_mkdev_acl,
 944                                             head)->perm;
 945                         for (i = 0; i < TOMOYO_MAX_MKDEV_OPERATION; i++)
 946                                 if (perm & (1 << i))
 947                                         count++;
 948                         break;
 949                 default:
 950                         count++;
 951                 }
 952         }
 953         if (count < tomoyo_profile(domain->profile)->learning->
 954             learning_max_entry)
 955                 return true;
 956         if (!domain->quota_warned) {
 957                 domain->quota_warned = true;
 958                 printk(KERN_WARNING "TOMOYO-WARNING: "
 959                        "Domain '%s' has so many ACLs to hold. "
 960                        "Stopped learning mode.\n", domain->domainname->name);
 961         }
 962         return false;
 963 }