security/tomoyo/util.c

   1 /*
   2  * security/tomoyo/util.c
   3  *
   4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   5  */
   6
   7 #include <linux/slab.h>
   8 #include "common.h"
   9
  10 /* Lock for protecting policy. */
  11 DEFINE_MUTEX(tomoyo_policy_lock);
  12
  13 /* Has /sbin/init started? */
  14 bool tomoyo_policy_loaded;
  15
  16 /*
  17  * Mapping table from "enum tomoyo_mac_index" to
  18  * "enum tomoyo_mac_category_index".
  19  */
  20 const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
  21         /* CONFIG::file group */
  22         [TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
  23         [TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
  24         [TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
  25         [TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
  26         [TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
  27         [TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
  28         [TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
  29         [TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
  30         [TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
  31         [TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
  32         [TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
  33         [TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
  34         [TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
  35         [TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
  36         [TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
  37         [TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
  38         [TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
  39         [TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
  40         [TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
  41         [TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
  42         [TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
  43         [TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
  44         [TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,
  45 };
  46
  47 /**
  48  * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
  49  *
  50  * @time:  Seconds since 1970/01/01 00:00:00.
  51  * @stamp: Pointer to "struct tomoyo_time".
  52  *
  53  * Returns nothing.
  54  *
  55  * This function does not handle Y2038 problem.
  56  */
  57 void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
  58 {
  59         static const u16 tomoyo_eom[2][12] = {
  60                 { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
  61                 { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
  62         };
  63         u16 y;
  64         u8 m;
  65         bool r;
  66         stamp->sec = time % 60;
  67         time /= 60;
  68         stamp->min = time % 60;
  69         time /= 60;
  70         stamp->hour = time % 24;
  71         time /= 24;
  72         for (y = 1970; ; y++) {
  73                 const unsigned short days = (y & 3) ? 365 : 366;
  74                 if (time < days)
  75                         break;
  76                 time -= days;
  77         }
  78         r = (y & 3) == 0;
  79         for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
  80                 ;
  81         if (m)
  82                 time -= tomoyo_eom[r][m - 1];
  83         stamp->year = y;
  84         stamp->month = ++m;
  85         stamp->day = ++time;
  86 }
  87
  88 /**
  89  * tomoyo_permstr - Find permission keywords.
  90  *
  91  * @string: String representation for permissions in foo/bar/buz format.
  92  * @keyword: Keyword to find from @string/
  93  *
  94  * Returns ture if @keyword was found in @string, false otherwise.
  95  *
  96  * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
  97  */
  98 bool tomoyo_permstr(const char *string, const char *keyword)
  99 {
 100         const char *cp = strstr(string, keyword);
 101         if (cp)
 102                 return cp == string || *(cp - 1) == '/';
 103         return false;
 104 }
 105
 106 /**
 107  * tomoyo_read_token - Read a word from a line.
 108  *
 109  * @param: Pointer to "struct tomoyo_acl_param".
 110  *
 111  * Returns a word on success, "" otherwise.
 112  *
 113  * To allow the caller to skip NULL check, this function returns "" rather than
 114  * NULL if there is no more words to read.
 115  */
 116 char *tomoyo_read_token(struct tomoyo_acl_param *param)
 117 {
 118         char *pos = param->data;
 119         char *del = strchr(pos, ' ');
 120         if (del)
 121                 *del++ = '\0';
 122         else
 123                 del = pos + strlen(pos);
 124         param->data = del;
 125         return pos;
 126 }
 127
 128 /**
 129  * tomoyo_parse_ulong - Parse an "unsigned long" value.
 130  *
 131  * @result: Pointer to "unsigned long".
 132  * @str:    Pointer to string to parse.
 133  *
 134  * Returns one of values in "enum tomoyo_value_type".
 135  *
 136  * The @src is updated to point the first character after the value
 137  * on success.
 138  */
 139 u8 tomoyo_parse_ulong(unsigned long *result, char **str)
 140 {
 141         const char *cp = *str;
 142         char *ep;
 143         int base = 10;
 144         if (*cp == '0') {
 145                 char c = *(cp + 1);
 146                 if (c == 'x' || c == 'X') {
 147                         base = 16;
 148                         cp += 2;
 149                 } else if (c >= '0' && c <= '7') {
 150                         base = 8;
 151                         cp++;
 152                 }
 153         }
 154         *result = simple_strtoul(cp, &ep, base);
 155         if (cp == ep)
 156                 return TOMOYO_VALUE_TYPE_INVALID;
 157         *str = ep;
 158         switch (base) {
 159         case 16:
 160                 return TOMOYO_VALUE_TYPE_HEXADECIMAL;
 161         case 8:
 162                 return TOMOYO_VALUE_TYPE_OCTAL;
 163         default:
 164                 return TOMOYO_VALUE_TYPE_DECIMAL;
 165         }
 166 }
 167
 168 /**
 169  * tomoyo_print_ulong - Print an "unsigned long" value.
 170  *
 171  * @buffer:     Pointer to buffer.
 172  * @buffer_len: Size of @buffer.
 173  * @value:      An "unsigned long" value.
 174  * @type:       Type of @value.
 175  *
 176  * Returns nothing.
 177  */
 178 void tomoyo_print_ulong(char *buffer, const int buffer_len,
 179                         const unsigned long value, const u8 type)
 180 {
 181         if (type == TOMOYO_VALUE_TYPE_DECIMAL)
 182                 snprintf(buffer, buffer_len, "%lu", value);
 183         else if (type == TOMOYO_VALUE_TYPE_OCTAL)
 184                 snprintf(buffer, buffer_len, "0%lo", value);
 185         else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
 186                 snprintf(buffer, buffer_len, "0x%lX", value);
 187         else
 188                 snprintf(buffer, buffer_len, "type(%u)", type);
 189 }
 190
 191 /**
 192  * tomoyo_parse_name_union - Parse a tomoyo_name_union.
 193  *
 194  * @param: Pointer to "struct tomoyo_acl_param".
 195  * @ptr:   Pointer to "struct tomoyo_name_union".
 196  *
 197  * Returns true on success, false otherwise.
 198  */
 199 bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,
 200                              struct tomoyo_name_union *ptr)
 201 {
 202         char *filename;
 203         if (param->data[0] == '@') {
 204                 param->data++;
 205                 ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);
 206                 return ptr->group != NULL;
 207         }
 208         filename = tomoyo_read_token(param);
 209         if (!tomoyo_correct_word(filename))
 210                 return false;
 211         ptr->filename = tomoyo_get_name(filename);
 212         return ptr->filename != NULL;
 213 }
 214
 215 /**
 216  * tomoyo_parse_number_union - Parse a tomoyo_number_union.
 217  *
 218  * @param: Pointer to "struct tomoyo_acl_param".
 219  * @ptr:   Pointer to "struct tomoyo_number_union".
 220  *
 221  * Returns true on success, false otherwise.
 222  */
 223 bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
 224                                struct tomoyo_number_union *ptr)
 225 {
 226         char *data;
 227         u8 type;
 228         unsigned long v;
 229         memset(ptr, 0, sizeof(*ptr));
 230         if (param->data[0] == '@') {
 231                 param->data++;
 232                 ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
 233                 return ptr->group != NULL;
 234         }
 235         data = tomoyo_read_token(param);
 236         type = tomoyo_parse_ulong(&v, &data);
 237         if (type == TOMOYO_VALUE_TYPE_INVALID)
 238                 return false;
 239         ptr->values[0] = v;
 240         ptr->value_type[0] = type;
 241         if (!*data) {
 242                 ptr->values[1] = v;
 243                 ptr->value_type[1] = type;
 244                 return true;
 245         }
 246         if (*data++ != '-')
 247                 return false;
 248         type = tomoyo_parse_ulong(&v, &data);
 249         if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)
 250                 return false;
 251         ptr->values[1] = v;
 252         ptr->value_type[1] = type;
 253         return true;
 254 }
 255
 256 /**
 257  * tomoyo_byte_range - Check whether the string is a \ooo style octal value.
 258  *
 259  * @str: Pointer to the string.
 260  *
 261  * Returns true if @str is a \ooo style octal value, false otherwise.
 262  *
 263  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
 264  * This function verifies that \ooo is in valid range.
 265  */
 266 static inline bool tomoyo_byte_range(const char *str)
 267 {
 268         return *str >= '0' && *str++ <= '3' &&
 269                 *str >= '0' && *str++ <= '7' &&
 270                 *str >= '0' && *str <= '7';
 271 }
 272
 273 /**
 274  * tomoyo_alphabet_char - Check whether the character is an alphabet.
 275  *
 276  * @c: The character to check.
 277  *
 278  * Returns true if @c is an alphabet character, false otherwise.
 279  */
 280 static inline bool tomoyo_alphabet_char(const char c)
 281 {
 282         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 283 }
 284
 285 /**
 286  * tomoyo_make_byte - Make byte value from three octal characters.
 287  *
 288  * @c1: The first character.
 289  * @c2: The second character.
 290  * @c3: The third character.
 291  *
 292  * Returns byte value.
 293  */
 294 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 295 {
 296         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 297 }
 298
 299 /**
 300  * tomoyo_valid - Check whether the character is a valid char.
 301  *
 302  * @c: The character to check.
 303  *
 304  * Returns true if @c is a valid character, false otherwise.
 305  */
 306 static inline bool tomoyo_valid(const unsigned char c)
 307 {
 308         return c > ' ' && c < 127;
 309 }
 310
 311 /**
 312  * tomoyo_invalid - Check whether the character is an invalid char.
 313  *
 314  * @c: The character to check.
 315  *
 316  * Returns true if @c is an invalid character, false otherwise.
 317  */
 318 static inline bool tomoyo_invalid(const unsigned char c)
 319 {
 320         return c && (c <= ' ' || c >= 127);
 321 }
 322
 323 /**
 324  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 325  *
 326  * @src:  Pointer to pointer to the string.
 327  * @find: Pointer to the keyword.
 328  *
 329  * Returns true if @src starts with @find, false otherwise.
 330  *
 331  * The @src is updated to point the first character after the @find
 332  * if @src starts with @find.
 333  */
 334 bool tomoyo_str_starts(char **src, const char *find)
 335 {
 336         const int len = strlen(find);
 337         char *tmp = *src;
 338
 339         if (strncmp(tmp, find, len))
 340                 return false;
 341         tmp += len;
 342         *src = tmp;
 343         return true;
 344 }
 345
 346 /**
 347  * tomoyo_normalize_line - Format string.
 348  *
 349  * @buffer: The line to normalize.
 350  *
 351  * Leading and trailing whitespaces are removed.
 352  * Multiple whitespaces are packed into single space.
 353  *
 354  * Returns nothing.
 355  */
 356 void tomoyo_normalize_line(unsigned char *buffer)
 357 {
 358         unsigned char *sp = buffer;
 359         unsigned char *dp = buffer;
 360         bool first = true;
 361
 362         while (tomoyo_invalid(*sp))
 363                 sp++;
 364         while (*sp) {
 365                 if (!first)
 366                         *dp++ = ' ';
 367                 first = false;
 368                 while (tomoyo_valid(*sp))
 369                         *dp++ = *sp++;
 370                 while (tomoyo_invalid(*sp))
 371                         sp++;
 372         }
 373         *dp = '\0';
 374 }
 375
 376 /**
 377  * tomoyo_correct_word2 - Validate a string.
 378  *
 379  * @string: The string to check. Maybe non-'\0'-terminated.
 380  * @len:    Length of @string.
 381  *
 382  * Check whether the given string follows the naming rules.
 383  * Returns true if @string follows the naming rules, false otherwise.
 384  */
 385 static bool tomoyo_correct_word2(const char *string, size_t len)
 386 {
 387         const char *const start = string;
 388         bool in_repetition = false;
 389         unsigned char c;
 390         unsigned char d;
 391         unsigned char e;
 392         if (!len)
 393                 goto out;
 394         while (len--) {
 395                 c = *string++;
 396                 if (c == '\\') {
 397                         if (!len--)
 398                                 goto out;
 399                         c = *string++;
 400                         switch (c) {
 401                         case '\\':  /* "\\" */
 402                                 continue;
 403                         case '$':   /* "\$" */
 404                         case '+':   /* "\+" */
 405                         case '?':   /* "\?" */
 406                         case '*':   /* "\*" */
 407                         case '@':   /* "\@" */
 408                         case 'x':   /* "\x" */
 409                         case 'X':   /* "\X" */
 410                         case 'a':   /* "\a" */
 411                         case 'A':   /* "\A" */
 412                         case '-':   /* "\-" */
 413                                 continue;
 414                         case '{':   /* "/\{" */
 415                                 if (string - 3 < start || *(string - 3) != '/')
 416                                         break;
 417                                 in_repetition = true;
 418                                 continue;
 419                         case '}':   /* "\}/" */
 420                                 if (*string != '/')
 421                                         break;
 422                                 if (!in_repetition)
 423                                         break;
 424                                 in_repetition = false;
 425                                 continue;
 426                         case '0':   /* "\ooo" */
 427                         case '1':
 428                         case '2':
 429                         case '3':
 430                                 if (!len-- || !len--)
 431                                         break;
 432                                 d = *string++;
 433                                 e = *string++;
 434                                 if (d < '0' || d > '7' || e < '0' || e > '7')
 435                                         break;
 436                                 c = tomoyo_make_byte(c, d, e);
 437                                 if (tomoyo_invalid(c))
 438                                         continue; /* pattern is not \000 */
 439                         }
 440                         goto out;
 441                 } else if (in_repetition && c == '/') {
 442                         goto out;
 443                 } else if (tomoyo_invalid(c)) {
 444                         goto out;
 445                 }
 446         }
 447         if (in_repetition)
 448                 goto out;
 449         return true;
 450  out:
 451         return false;
 452 }
 453
 454 /**
 455  * tomoyo_correct_word - Validate a string.
 456  *
 457  * @string: The string to check.
 458  *
 459  * Check whether the given string follows the naming rules.
 460  * Returns true if @string follows the naming rules, false otherwise.
 461  */
 462 bool tomoyo_correct_word(const char *string)
 463 {
 464         return tomoyo_correct_word2(string, strlen(string));
 465 }
 466
 467 /**
 468  * tomoyo_correct_path - Validate a pathname.
 469  *
 470  * @filename: The pathname to check.
 471  *
 472  * Check whether the given pathname follows the naming rules.
 473  * Returns true if @filename follows the naming rules, false otherwise.
 474  */
 475 bool tomoyo_correct_path(const char *filename)
 476 {
 477         return *filename == '/' && tomoyo_correct_word(filename);
 478 }
 479
 480 /**
 481  * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.
 482  *
 483  * @domainname: The domainname to check.
 484  *
 485  * Returns true if @domainname follows the naming rules, false otherwise.
 486  */
 487 bool tomoyo_correct_domain(const unsigned char *domainname)
 488 {
 489         if (!domainname || !tomoyo_domain_def(domainname))
 490                 return false;
 491         domainname = strchr(domainname, ' ');
 492         if (!domainname++)
 493                 return true;
 494         while (1) {
 495                 const unsigned char *cp = strchr(domainname, ' ');
 496                 if (!cp)
 497                         break;
 498                 if (*domainname != '/' ||
 499                     !tomoyo_correct_word2(domainname, cp - domainname))
 500                         return false;
 501                 domainname = cp + 1;
 502         }
 503         return tomoyo_correct_path(domainname);
 504 }
 505
 506 /**
 507  * tomoyo_domain_def - Check whether the given token can be a domainname.
 508  *
 509  * @buffer: The token to check.
 510  *
 511  * Returns true if @buffer possibly be a domainname, false otherwise.
 512  */
 513 bool tomoyo_domain_def(const unsigned char *buffer)
 514 {
 515         const unsigned char *cp;
 516         int len;
 517         if (*buffer != '<')
 518                 return false;
 519         cp = strchr(buffer, ' ');
 520         if (!cp)
 521                 len = strlen(buffer);
 522         else
 523                 len = cp - buffer;
 524         if (buffer[len - 1] != '>' ||
 525             !tomoyo_correct_word2(buffer + 1, len - 2))
 526                 return false;
 527         return true;
 528 }
 529
 530 /**
 531  * tomoyo_find_domain - Find a domain by the given name.
 532  *
 533  * @domainname: The domainname to find.
 534  *
 535  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 536  *
 537  * Caller holds tomoyo_read_lock().
 538  */
 539 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 540 {
 541         struct tomoyo_domain_info *domain;
 542         struct tomoyo_path_info name;
 543
 544         name.name = domainname;
 545         tomoyo_fill_path_info(&name);
 546         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 547                 if (!domain->is_deleted &&
 548                     !tomoyo_pathcmp(&name, domain->domainname))
 549                         return domain;
 550         }
 551         return NULL;
 552 }
 553
 554 /**
 555  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 556  *
 557  * @filename: The string to evaluate.
 558  *
 559  * Returns the initial length without a pattern in @filename.
 560  */
 561 static int tomoyo_const_part_length(const char *filename)
 562 {
 563         char c;
 564         int len = 0;
 565
 566         if (!filename)
 567                 return 0;
 568         while ((c = *filename++) != '\0') {
 569                 if (c != '\\') {
 570                         len++;
 571                         continue;
 572                 }
 573                 c = *filename++;
 574                 switch (c) {
 575                 case '\\':  /* "\\" */
 576                         len += 2;
 577                         continue;
 578                 case '0':   /* "\ooo" */
 579                 case '1':
 580                 case '2':
 581                 case '3':
 582                         c = *filename++;
 583                         if (c < '0' || c > '7')
 584                                 break;
 585                         c = *filename++;
 586                         if (c < '0' || c > '7')
 587                                 break;
 588                         len += 4;
 589                         continue;
 590                 }
 591                 break;
 592         }
 593         return len;
 594 }
 595
 596 /**
 597  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 598  *
 599  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 600  *
 601  * The caller sets "struct tomoyo_path_info"->name.
 602  */
 603 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 604 {
 605         const char *name = ptr->name;
 606         const int len = strlen(name);
 607
 608         ptr->const_len = tomoyo_const_part_length(name);
 609         ptr->is_dir = len && (name[len - 1] == '/');
 610         ptr->is_patterned = (ptr->const_len < len);
 611         ptr->hash = full_name_hash(name, len);
 612 }
 613
 614 /**
 615  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
 616  *
 617  * @filename:     The start of string to check.
 618  * @filename_end: The end of string to check.
 619  * @pattern:      The start of pattern to compare.
 620  * @pattern_end:  The end of pattern to compare.
 621  *
 622  * Returns true if @filename matches @pattern, false otherwise.
 623  */
 624 static bool tomoyo_file_matches_pattern2(const char *filename,
 625                                          const char *filename_end,
 626                                          const char *pattern,
 627                                          const char *pattern_end)
 628 {
 629         while (filename < filename_end && pattern < pattern_end) {
 630                 char c;
 631                 if (*pattern != '\\') {
 632                         if (*filename++ != *pattern++)
 633                                 return false;
 634                         continue;
 635                 }
 636                 c = *filename;
 637                 pattern++;
 638                 switch (*pattern) {
 639                         int i;
 640                         int j;
 641                 case '?':
 642                         if (c == '/') {
 643                                 return false;
 644                         } else if (c == '\\') {
 645                                 if (filename[1] == '\\')
 646                                         filename++;
 647                                 else if (tomoyo_byte_range(filename + 1))
 648                                         filename += 3;
 649                                 else
 650                                         return false;
 651                         }
 652                         break;
 653                 case '\\':
 654                         if (c != '\\')
 655                                 return false;
 656                         if (*++filename != '\\')
 657                                 return false;
 658                         break;
 659                 case '+':
 660                         if (!isdigit(c))
 661                                 return false;
 662                         break;
 663                 case 'x':
 664                         if (!isxdigit(c))
 665                                 return false;
 666                         break;
 667                 case 'a':
 668                         if (!tomoyo_alphabet_char(c))
 669                                 return false;
 670                         break;
 671                 case '0':
 672                 case '1':
 673                 case '2':
 674                 case '3':
 675                         if (c == '\\' && tomoyo_byte_range(filename + 1)
 676                             && strncmp(filename + 1, pattern, 3) == 0) {
 677                                 filename += 3;
 678                                 pattern += 2;
 679                                 break;
 680                         }
 681                         return false; /* Not matched. */
 682                 case '*':
 683                 case '@':
 684                         for (i = 0; i <= filename_end - filename; i++) {
 685                                 if (tomoyo_file_matches_pattern2(
 686                                                     filename + i, filename_end,
 687                                                     pattern + 1, pattern_end))
 688                                         return true;
 689                                 c = filename[i];
 690                                 if (c == '.' && *pattern == '@')
 691                                         break;
 692                                 if (c != '\\')
 693                                         continue;
 694                                 if (filename[i + 1] == '\\')
 695                                         i++;
 696                                 else if (tomoyo_byte_range(filename + i + 1))
 697                                         i += 3;
 698                                 else
 699                                         break; /* Bad pattern. */
 700                         }
 701                         return false; /* Not matched. */
 702                 default:
 703                         j = 0;
 704                         c = *pattern;
 705                         if (c == '$') {
 706                                 while (isdigit(filename[j]))
 707                                         j++;
 708                         } else if (c == 'X') {
 709                                 while (isxdigit(filename[j]))
 710                                         j++;
 711                         } else if (c == 'A') {
 712                                 while (tomoyo_alphabet_char(filename[j]))
 713                                         j++;
 714                         }
 715                         for (i = 1; i <= j; i++) {
 716                                 if (tomoyo_file_matches_pattern2(
 717                                                     filename + i, filename_end,
 718                                                     pattern + 1, pattern_end))
 719                                         return true;
 720                         }
 721                         return false; /* Not matched or bad pattern. */
 722                 }
 723                 filename++;
 724                 pattern++;
 725         }
 726         while (*pattern == '\\' &&
 727                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 728                 pattern += 2;
 729         return filename == filename_end && pattern == pattern_end;
 730 }
 731
 732 /**
 733  * tomoyo_file_matches_pattern - Pattern matching without '/' character.
 734  *
 735  * @filename:     The start of string to check.
 736  * @filename_end: The end of string to check.
 737  * @pattern:      The start of pattern to compare.
 738  * @pattern_end:  The end of pattern to compare.
 739  *
 740  * Returns true if @filename matches @pattern, false otherwise.
 741  */
 742 static bool tomoyo_file_matches_pattern(const char *filename,
 743                                         const char *filename_end,
 744                                         const char *pattern,
 745                                         const char *pattern_end)
 746 {
 747         const char *pattern_start = pattern;
 748         bool first = true;
 749         bool result;
 750
 751         while (pattern < pattern_end - 1) {
 752                 /* Split at "\-" pattern. */
 753                 if (*pattern++ != '\\' || *pattern++ != '-')
 754                         continue;
 755                 result = tomoyo_file_matches_pattern2(filename,
 756                                                       filename_end,
 757                                                       pattern_start,
 758                                                       pattern - 2);
 759                 if (first)
 760                         result = !result;
 761                 if (result)
 762                         return false;
 763                 first = false;
 764                 pattern_start = pattern;
 765         }
 766         result = tomoyo_file_matches_pattern2(filename, filename_end,
 767                                               pattern_start, pattern_end);
 768         return first ? result : !result;
 769 }
 770
 771 /**
 772  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 773  *
 774  * @f: The start of string to check.
 775  * @p: The start of pattern to compare.
 776  *
 777  * Returns true if @f matches @p, false otherwise.
 778  */
 779 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 780 {
 781         const char *f_delimiter;
 782         const char *p_delimiter;
 783
 784         while (*f && *p) {
 785                 f_delimiter = strchr(f, '/');
 786                 if (!f_delimiter)
 787                         f_delimiter = f + strlen(f);
 788                 p_delimiter = strchr(p, '/');
 789                 if (!p_delimiter)
 790                         p_delimiter = p + strlen(p);
 791                 if (*p == '\\' && *(p + 1) == '{')
 792                         goto recursive;
 793                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 794                                                  p_delimiter))
 795                         return false;
 796                 f = f_delimiter;
 797                 if (*f)
 798                         f++;
 799                 p = p_delimiter;
 800                 if (*p)
 801                         p++;
 802         }
 803         /* Ignore trailing "\*" and "\@" in @pattern. */
 804         while (*p == '\\' &&
 805                (*(p + 1) == '*' || *(p + 1) == '@'))
 806                 p += 2;
 807         return !*f && !*p;
 808  recursive:
 809         /*
 810          * The "\{" pattern is permitted only after '/' character.
 811          * This guarantees that below "*(p - 1)" is safe.
 812          * Also, the "\}" pattern is permitted only before '/' character
 813          * so that "\{" + "\}" pair will not break the "\-" operator.
 814          */
 815         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 816             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 817                 return false; /* Bad pattern. */
 818         do {
 819                 /* Compare current component with pattern. */
 820                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 821                                                  p_delimiter - 2))
 822                         break;
 823                 /* Proceed to next component. */
 824                 f = f_delimiter;
 825                 if (!*f)
 826                         break;
 827                 f++;
 828                 /* Continue comparison. */
 829                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 830                         return true;
 831                 f_delimiter = strchr(f, '/');
 832         } while (f_delimiter);
 833         return false; /* Not matched. */
 834 }
 835
 836 /**
 837  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 838  *
 839  * @filename: The filename to check.
 840  * @pattern:  The pattern to compare.
 841  *
 842  * Returns true if matches, false otherwise.
 843  *
 844  * The following patterns are available.
 845  *   \\     \ itself.
 846  *   \ooo   Octal representation of a byte.
 847  *   \*     Zero or more repetitions of characters other than '/'.
 848  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 849  *   \?     1 byte character other than '/'.
 850  *   \$     One or more repetitions of decimal digits.
 851  *   \+     1 decimal digit.
 852  *   \X     One or more repetitions of hexadecimal digits.
 853  *   \x     1 hexadecimal digit.
 854  *   \A     One or more repetitions of alphabet characters.
 855  *   \a     1 alphabet character.
 856  *
 857  *   \-     Subtraction operator.
 858  *
 859  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 860  *               /dir/dir/dir/ ).
 861  */
 862 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 863                                  const struct tomoyo_path_info *pattern)
 864 {
 865         const char *f = filename->name;
 866         const char *p = pattern->name;
 867         const int len = pattern->const_len;
 868
 869         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 870         if (!pattern->is_patterned)
 871                 return !tomoyo_pathcmp(filename, pattern);
 872         /* Don't compare directory and non-directory. */
 873         if (filename->is_dir != pattern->is_dir)
 874                 return false;
 875         /* Compare the initial length without patterns. */
 876         if (strncmp(f, p, len))
 877                 return false;
 878         f += len;
 879         p += len;
 880         return tomoyo_path_matches_pattern2(f, p);
 881 }
 882
 883 /**
 884  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 885  *
 886  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 887  *
 888  * This function uses kzalloc(), so the caller must call kfree()
 889  * if this function didn't return NULL.
 890  */
 891 const char *tomoyo_get_exe(void)
 892 {
 893         struct mm_struct *mm = current->mm;
 894         struct vm_area_struct *vma;
 895         const char *cp = NULL;
 896
 897         if (!mm)
 898                 return NULL;
 899         down_read(&mm->mmap_sem);
 900         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 901                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 902                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 903                         break;
 904                 }
 905         }
 906         up_read(&mm->mmap_sem);
 907         return cp;
 908 }
 909
 910 /**
 911  * tomoyo_get_mode - Get MAC mode.
 912  *
 913  * @ns:      Pointer to "struct tomoyo_policy_namespace".
 914  * @profile: Profile number.
 915  * @index:   Index number of functionality.
 916  *
 917  * Returns mode.
 918  */
 919 int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
 920                     const u8 index)
 921 {
 922         u8 mode;
 923         const u8 category = TOMOYO_MAC_CATEGORY_FILE;
 924         if (!tomoyo_policy_loaded)
 925                 return TOMOYO_CONFIG_DISABLED;
 926         mode = tomoyo_profile(ns, profile)->config[index];
 927         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
 928                 mode = tomoyo_profile(ns, profile)->config[category];
 929         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
 930                 mode = tomoyo_profile(ns, profile)->default_config;
 931         return mode & 3;
 932 }
 933
 934 /**
 935  * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
 936  *
 937  * @r:      Pointer to "struct tomoyo_request_info" to initialize.
 938  * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().
 939  * @index:  Index number of functionality.
 940  *
 941  * Returns mode.
 942  */
 943 int tomoyo_init_request_info(struct tomoyo_request_info *r,
 944                              struct tomoyo_domain_info *domain, const u8 index)
 945 {
 946         u8 profile;
 947         memset(r, 0, sizeof(*r));
 948         if (!domain)
 949                 domain = tomoyo_domain();
 950         r->domain = domain;
 951         profile = domain->profile;
 952         r->profile = profile;
 953         r->type = index;
 954         r->mode = tomoyo_get_mode(domain->ns, profile, index);
 955         return r->mode;
 956 }
 957
 958 /**
 959  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 960  *
 961  * @r: Pointer to "struct tomoyo_request_info".
 962  *
 963  * Returns true if the domain is not exceeded quota, false otherwise.
 964  *
 965  * Caller holds tomoyo_read_lock().
 966  */
 967 bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
 968 {
 969         unsigned int count = 0;
 970         struct tomoyo_domain_info *domain = r->domain;
 971         struct tomoyo_acl_info *ptr;
 972
 973         if (r->mode != TOMOYO_CONFIG_LEARNING)
 974                 return false;
 975         if (!domain)
 976                 return true;
 977         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 978                 u16 perm;
 979                 u8 i;
 980                 if (ptr->is_deleted)
 981                         continue;
 982                 switch (ptr->type) {
 983                 case TOMOYO_TYPE_PATH_ACL:
 984                         perm = container_of(ptr, struct tomoyo_path_acl, head)
 985                                 ->perm;
 986                         break;
 987                 case TOMOYO_TYPE_PATH2_ACL:
 988                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
 989                                 ->perm;
 990                         break;
 991                 case TOMOYO_TYPE_PATH_NUMBER_ACL:
 992                         perm = container_of(ptr, struct tomoyo_path_number_acl,
 993                                             head)->perm;
 994                         break;
 995                 case TOMOYO_TYPE_MKDEV_ACL:
 996                         perm = container_of(ptr, struct tomoyo_mkdev_acl,
 997                                             head)->perm;
 998                         break;
 999                 default:
1000                         perm = 1;
1001                 }
1002                 for (i = 0; i < 16; i++)
1003                         if (perm & (1 << i))
1004                                 count++;
1005         }
1006         if (count < tomoyo_profile(domain->ns, domain->profile)->
1007             pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])
1008                 return true;
1009         if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
1010                 domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
1011                 /* r->granted = false; */
1012                 tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
1013                 printk(KERN_WARNING "WARNING: "
1014                        "Domain '%s' has too many ACLs to hold. "
1015                        "Stopped learning mode.\n", domain->domainname->name);
1016         }
1017         return false;
1018 }