security/tomoyo/common.c

   1 /*
   2  * security/tomoyo/common.c
   3  *
   4  * Common functions for TOMOYO.
   5  *
   6  * Copyright (C) 2005-2009  NTT DATA CORPORATION
   7  *
   8  * Version: 2.2.0   2009/04/01
   9  *
  10  */
  11
  12 #include <linux/uaccess.h>
  13 #include <linux/security.h>
  14 #include <linux/hardirq.h>
  15 #include "common.h"
  16
  17 /* Lock for protecting policy. */
  18 DEFINE_MUTEX(tomoyo_policy_lock);
  19
  20 /* Has loading policy done? */
  21 bool tomoyo_policy_loaded;
  22
  23 /* String table for functionality that takes 4 modes. */
  24 static const char *tomoyo_mode_4[4] = {
  25         "disabled", "learning", "permissive", "enforcing"
  26 };
  27 /* String table for functionality that takes 2 modes. */
  28 static const char *tomoyo_mode_2[4] = {
  29         "disabled", "enabled", "enabled", "enabled"
  30 };
  31
  32 /*
  33  * tomoyo_control_array is a static data which contains
  34  *
  35  *  (1) functionality name used by /sys/kernel/security/tomoyo/profile .
  36  *  (2) initial values for "struct tomoyo_profile".
  37  *  (3) max values for "struct tomoyo_profile".
  38  */
  39 static struct {
  40         const char *keyword;
  41         unsigned int current_value;
  42         const unsigned int max_value;
  43 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
  44         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
  45         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
  46         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
  47 };
  48
  49 /*
  50  * tomoyo_profile is a structure which is used for holding the mode of access
  51  * controls. TOMOYO has 4 modes: disabled, learning, permissive, enforcing.
  52  * An administrator can define up to 256 profiles.
  53  * The ->profile of "struct tomoyo_domain_info" is used for remembering
  54  * the profile's number (0 - 255) assigned to that domain.
  55  */
  56 static struct tomoyo_profile {
  57         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
  58         const struct tomoyo_path_info *comment;
  59 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
  60
  61 /* Permit policy management by non-root user? */
  62 static bool tomoyo_manage_by_non_root;
  63
  64 /* Utility functions. */
  65
  66 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
  67 static int tomoyo_open_control(const u8 type, struct file *file);
  68 /* Close /sys/kernel/security/tomoyo/ interface. */
  69 static int tomoyo_close_control(struct file *file);
  70 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
  71 static int tomoyo_read_control(struct file *file, char __user *buffer,
  72                                const int buffer_len);
  73 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
  74 static int tomoyo_write_control(struct file *file, const char __user *buffer,
  75                                 const int buffer_len);
  76
  77 /**
  78  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
  79  *
  80  * @str: Pointer to the string.
  81  *
  82  * Returns true if @str is a \ooo style octal value, false otherwise.
  83  *
  84  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
  85  * This function verifies that \ooo is in valid range.
  86  */
  87 static inline bool tomoyo_is_byte_range(const char *str)
  88 {
  89         return *str >= '0' && *str++ <= '3' &&
  90                 *str >= '0' && *str++ <= '7' &&
  91                 *str >= '0' && *str <= '7';
  92 }
  93
  94 /**
  95  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
  96  *
  97  * @c: The character to check.
  98  *
  99  * Returns true if @c is an alphabet character, false otherwise.
 100  */
 101 static inline bool tomoyo_is_alphabet_char(const char c)
 102 {
 103         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 104 }
 105
 106 /**
 107  * tomoyo_make_byte - Make byte value from three octal characters.
 108  *
 109  * @c1: The first character.
 110  * @c2: The second character.
 111  * @c3: The third character.
 112  *
 113  * Returns byte value.
 114  */
 115 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 116 {
 117         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 118 }
 119
 120 /**
 121  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 122  *
 123  * @src:  Pointer to pointer to the string.
 124  * @find: Pointer to the keyword.
 125  *
 126  * Returns true if @src starts with @find, false otherwise.
 127  *
 128  * The @src is updated to point the first character after the @find
 129  * if @src starts with @find.
 130  */
 131 static bool tomoyo_str_starts(char **src, const char *find)
 132 {
 133         const int len = strlen(find);
 134         char *tmp = *src;
 135
 136         if (strncmp(tmp, find, len))
 137                 return false;
 138         tmp += len;
 139         *src = tmp;
 140         return true;
 141 }
 142
 143 /**
 144  * tomoyo_normalize_line - Format string.
 145  *
 146  * @buffer: The line to normalize.
 147  *
 148  * Leading and trailing whitespaces are removed.
 149  * Multiple whitespaces are packed into single space.
 150  *
 151  * Returns nothing.
 152  */
 153 static void tomoyo_normalize_line(unsigned char *buffer)
 154 {
 155         unsigned char *sp = buffer;
 156         unsigned char *dp = buffer;
 157         bool first = true;
 158
 159         while (tomoyo_is_invalid(*sp))
 160                 sp++;
 161         while (*sp) {
 162                 if (!first)
 163                         *dp++ = ' ';
 164                 first = false;
 165                 while (tomoyo_is_valid(*sp))
 166                         *dp++ = *sp++;
 167                 while (tomoyo_is_invalid(*sp))
 168                         sp++;
 169         }
 170         *dp = '\0';
 171 }
 172
 173 /**
 174  * tomoyo_is_correct_path - Validate a pathname.
 175  * @filename:     The pathname to check.
 176  * @start_type:   Should the pathname start with '/'?
 177  *                1 = must / -1 = must not / 0 = don't care
 178  * @pattern_type: Can the pathname contain a wildcard?
 179  *                1 = must / -1 = must not / 0 = don't care
 180  * @end_type:     Should the pathname end with '/'?
 181  *                1 = must / -1 = must not / 0 = don't care
 182  *
 183  * Check whether the given filename follows the naming rules.
 184  * Returns true if @filename follows the naming rules, false otherwise.
 185  */
 186 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 187                             const s8 pattern_type, const s8 end_type)
 188 {
 189         const char *const start = filename;
 190         bool in_repetition = false;
 191         bool contains_pattern = false;
 192         unsigned char c;
 193         unsigned char d;
 194         unsigned char e;
 195
 196         if (!filename)
 197                 goto out;
 198         c = *filename;
 199         if (start_type == 1) { /* Must start with '/' */
 200                 if (c != '/')
 201                         goto out;
 202         } else if (start_type == -1) { /* Must not start with '/' */
 203                 if (c == '/')
 204                         goto out;
 205         }
 206         if (c)
 207                 c = *(filename + strlen(filename) - 1);
 208         if (end_type == 1) { /* Must end with '/' */
 209                 if (c != '/')
 210                         goto out;
 211         } else if (end_type == -1) { /* Must not end with '/' */
 212                 if (c == '/')
 213                         goto out;
 214         }
 215         while (1) {
 216                 c = *filename++;
 217                 if (!c)
 218                         break;
 219                 if (c == '\\') {
 220                         c = *filename++;
 221                         switch (c) {
 222                         case '\\':  /* "\\" */
 223                                 continue;
 224                         case '$':   /* "\$" */
 225                         case '+':   /* "\+" */
 226                         case '?':   /* "\?" */
 227                         case '*':   /* "\*" */
 228                         case '@':   /* "\@" */
 229                         case 'x':   /* "\x" */
 230                         case 'X':   /* "\X" */
 231                         case 'a':   /* "\a" */
 232                         case 'A':   /* "\A" */
 233                         case '-':   /* "\-" */
 234                                 if (pattern_type == -1)
 235                                         break; /* Must not contain pattern */
 236                                 contains_pattern = true;
 237                                 continue;
 238                         case '{':   /* "/\{" */
 239                                 if (filename - 3 < start ||
 240                                     *(filename - 3) != '/')
 241                                         break;
 242                                 if (pattern_type == -1)
 243                                         break; /* Must not contain pattern */
 244                                 contains_pattern = true;
 245                                 in_repetition = true;
 246                                 continue;
 247                         case '}':   /* "\}/" */
 248                                 if (*filename != '/')
 249                                         break;
 250                                 if (!in_repetition)
 251                                         break;
 252                                 in_repetition = false;
 253                                 continue;
 254                         case '0':   /* "\ooo" */
 255                         case '1':
 256                         case '2':
 257                         case '3':
 258                                 d = *filename++;
 259                                 if (d < '0' || d > '7')
 260                                         break;
 261                                 e = *filename++;
 262                                 if (e < '0' || e > '7')
 263                                         break;
 264                                 c = tomoyo_make_byte(c, d, e);
 265                                 if (tomoyo_is_invalid(c))
 266                                         continue; /* pattern is not \000 */
 267                         }
 268                         goto out;
 269                 } else if (in_repetition && c == '/') {
 270                         goto out;
 271                 } else if (tomoyo_is_invalid(c)) {
 272                         goto out;
 273                 }
 274         }
 275         if (pattern_type == 1) { /* Must contain pattern */
 276                 if (!contains_pattern)
 277                         goto out;
 278         }
 279         if (in_repetition)
 280                 goto out;
 281         return true;
 282  out:
 283         return false;
 284 }
 285
 286 /**
 287  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 288  * @domainname:   The domainname to check.
 289  *
 290  * Returns true if @domainname follows the naming rules, false otherwise.
 291  */
 292 bool tomoyo_is_correct_domain(const unsigned char *domainname)
 293 {
 294         unsigned char c;
 295         unsigned char d;
 296         unsigned char e;
 297
 298         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 299                                    TOMOYO_ROOT_NAME_LEN))
 300                 goto out;
 301         domainname += TOMOYO_ROOT_NAME_LEN;
 302         if (!*domainname)
 303                 return true;
 304         do {
 305                 if (*domainname++ != ' ')
 306                         goto out;
 307                 if (*domainname++ != '/')
 308                         goto out;
 309                 while ((c = *domainname) != '\0' && c != ' ') {
 310                         domainname++;
 311                         if (c == '\\') {
 312                                 c = *domainname++;
 313                                 switch ((c)) {
 314                                 case '\\':  /* "\\" */
 315                                         continue;
 316                                 case '0':   /* "\ooo" */
 317                                 case '1':
 318                                 case '2':
 319                                 case '3':
 320                                         d = *domainname++;
 321                                         if (d < '0' || d > '7')
 322                                                 break;
 323                                         e = *domainname++;
 324                                         if (e < '0' || e > '7')
 325                                                 break;
 326                                         c = tomoyo_make_byte(c, d, e);
 327                                         if (tomoyo_is_invalid(c))
 328                                                 /* pattern is not \000 */
 329                                                 continue;
 330                                 }
 331                                 goto out;
 332                         } else if (tomoyo_is_invalid(c)) {
 333                                 goto out;
 334                         }
 335                 }
 336         } while (*domainname);
 337         return true;
 338  out:
 339         return false;
 340 }
 341
 342 /**
 343  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 344  *
 345  * @buffer: The token to check.
 346  *
 347  * Returns true if @buffer possibly be a domainname, false otherwise.
 348  */
 349 bool tomoyo_is_domain_def(const unsigned char *buffer)
 350 {
 351         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 352 }
 353
 354 /**
 355  * tomoyo_find_domain - Find a domain by the given name.
 356  *
 357  * @domainname: The domainname to find.
 358  *
 359  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 360  *
 361  * Caller holds tomoyo_read_lock().
 362  */
 363 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 364 {
 365         struct tomoyo_domain_info *domain;
 366         struct tomoyo_path_info name;
 367
 368         name.name = domainname;
 369         tomoyo_fill_path_info(&name);
 370         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 371                 if (!domain->is_deleted &&
 372                     !tomoyo_pathcmp(&name, domain->domainname))
 373                         return domain;
 374         }
 375         return NULL;
 376 }
 377
 378 /**
 379  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 380  *
 381  * @filename: The string to evaluate.
 382  *
 383  * Returns the initial length without a pattern in @filename.
 384  */
 385 static int tomoyo_const_part_length(const char *filename)
 386 {
 387         char c;
 388         int len = 0;
 389
 390         if (!filename)
 391                 return 0;
 392         while ((c = *filename++) != '\0') {
 393                 if (c != '\\') {
 394                         len++;
 395                         continue;
 396                 }
 397                 c = *filename++;
 398                 switch (c) {
 399                 case '\\':  /* "\\" */
 400                         len += 2;
 401                         continue;
 402                 case '0':   /* "\ooo" */
 403                 case '1':
 404                 case '2':
 405                 case '3':
 406                         c = *filename++;
 407                         if (c < '0' || c > '7')
 408                                 break;
 409                         c = *filename++;
 410                         if (c < '0' || c > '7')
 411                                 break;
 412                         len += 4;
 413                         continue;
 414                 }
 415                 break;
 416         }
 417         return len;
 418 }
 419
 420 /**
 421  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 422  *
 423  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 424  *
 425  * The caller sets "struct tomoyo_path_info"->name.
 426  */
 427 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 428 {
 429         const char *name = ptr->name;
 430         const int len = strlen(name);
 431
 432         ptr->const_len = tomoyo_const_part_length(name);
 433         ptr->is_dir = len && (name[len - 1] == '/');
 434         ptr->is_patterned = (ptr->const_len < len);
 435         ptr->hash = full_name_hash(name, len);
 436 }
 437
 438 /**
 439  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
 440  * and "\-" pattern.
 441  *
 442  * @filename:     The start of string to check.
 443  * @filename_end: The end of string to check.
 444  * @pattern:      The start of pattern to compare.
 445  * @pattern_end:  The end of pattern to compare.
 446  *
 447  * Returns true if @filename matches @pattern, false otherwise.
 448  */
 449 static bool tomoyo_file_matches_pattern2(const char *filename,
 450                                          const char *filename_end,
 451                                          const char *pattern,
 452                                          const char *pattern_end)
 453 {
 454         while (filename < filename_end && pattern < pattern_end) {
 455                 char c;
 456                 if (*pattern != '\\') {
 457                         if (*filename++ != *pattern++)
 458                                 return false;
 459                         continue;
 460                 }
 461                 c = *filename;
 462                 pattern++;
 463                 switch (*pattern) {
 464                         int i;
 465                         int j;
 466                 case '?':
 467                         if (c == '/') {
 468                                 return false;
 469                         } else if (c == '\\') {
 470                                 if (filename[1] == '\\')
 471                                         filename++;
 472                                 else if (tomoyo_is_byte_range(filename + 1))
 473                                         filename += 3;
 474                                 else
 475                                         return false;
 476                         }
 477                         break;
 478                 case '\\':
 479                         if (c != '\\')
 480                                 return false;
 481                         if (*++filename != '\\')
 482                                 return false;
 483                         break;
 484                 case '+':
 485                         if (!isdigit(c))
 486                                 return false;
 487                         break;
 488                 case 'x':
 489                         if (!isxdigit(c))
 490                                 return false;
 491                         break;
 492                 case 'a':
 493                         if (!tomoyo_is_alphabet_char(c))
 494                                 return false;
 495                         break;
 496                 case '0':
 497                 case '1':
 498                 case '2':
 499                 case '3':
 500                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 501                             && strncmp(filename + 1, pattern, 3) == 0) {
 502                                 filename += 3;
 503                                 pattern += 2;
 504                                 break;
 505                         }
 506                         return false; /* Not matched. */
 507                 case '*':
 508                 case '@':
 509                         for (i = 0; i <= filename_end - filename; i++) {
 510                                 if (tomoyo_file_matches_pattern2(
 511                                                     filename + i, filename_end,
 512                                                     pattern + 1, pattern_end))
 513                                         return true;
 514                                 c = filename[i];
 515                                 if (c == '.' && *pattern == '@')
 516                                         break;
 517                                 if (c != '\\')
 518                                         continue;
 519                                 if (filename[i + 1] == '\\')
 520                                         i++;
 521                                 else if (tomoyo_is_byte_range(filename + i + 1))
 522                                         i += 3;
 523                                 else
 524                                         break; /* Bad pattern. */
 525                         }
 526                         return false; /* Not matched. */
 527                 default:
 528                         j = 0;
 529                         c = *pattern;
 530                         if (c == '$') {
 531                                 while (isdigit(filename[j]))
 532                                         j++;
 533                         } else if (c == 'X') {
 534                                 while (isxdigit(filename[j]))
 535                                         j++;
 536                         } else if (c == 'A') {
 537                                 while (tomoyo_is_alphabet_char(filename[j]))
 538                                         j++;
 539                         }
 540                         for (i = 1; i <= j; i++) {
 541                                 if (tomoyo_file_matches_pattern2(
 542                                                     filename + i, filename_end,
 543                                                     pattern + 1, pattern_end))
 544                                         return true;
 545                         }
 546                         return false; /* Not matched or bad pattern. */
 547                 }
 548                 filename++;
 549                 pattern++;
 550         }
 551         while (*pattern == '\\' &&
 552                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 553                 pattern += 2;
 554         return filename == filename_end && pattern == pattern_end;
 555 }
 556
 557 /**
 558  * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
 559  *
 560  * @filename:     The start of string to check.
 561  * @filename_end: The end of string to check.
 562  * @pattern:      The start of pattern to compare.
 563  * @pattern_end:  The end of pattern to compare.
 564  *
 565  * Returns true if @filename matches @pattern, false otherwise.
 566  */
 567 static bool tomoyo_file_matches_pattern(const char *filename,
 568                                            const char *filename_end,
 569                                            const char *pattern,
 570                                            const char *pattern_end)
 571 {
 572         const char *pattern_start = pattern;
 573         bool first = true;
 574         bool result;
 575
 576         while (pattern < pattern_end - 1) {
 577                 /* Split at "\-" pattern. */
 578                 if (*pattern++ != '\\' || *pattern++ != '-')
 579                         continue;
 580                 result = tomoyo_file_matches_pattern2(filename,
 581                                                       filename_end,
 582                                                       pattern_start,
 583                                                       pattern - 2);
 584                 if (first)
 585                         result = !result;
 586                 if (result)
 587                         return false;
 588                 first = false;
 589                 pattern_start = pattern;
 590         }
 591         result = tomoyo_file_matches_pattern2(filename, filename_end,
 592                                               pattern_start, pattern_end);
 593         return first ? result : !result;
 594 }
 595
 596 /**
 597  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 598  *
 599  * @f: The start of string to check.
 600  * @p: The start of pattern to compare.
 601  *
 602  * Returns true if @f matches @p, false otherwise.
 603  */
 604 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 605 {
 606         const char *f_delimiter;
 607         const char *p_delimiter;
 608
 609         while (*f && *p) {
 610                 f_delimiter = strchr(f, '/');
 611                 if (!f_delimiter)
 612                         f_delimiter = f + strlen(f);
 613                 p_delimiter = strchr(p, '/');
 614                 if (!p_delimiter)
 615                         p_delimiter = p + strlen(p);
 616                 if (*p == '\\' && *(p + 1) == '{')
 617                         goto recursive;
 618                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 619                                                  p_delimiter))
 620                         return false;
 621                 f = f_delimiter;
 622                 if (*f)
 623                         f++;
 624                 p = p_delimiter;
 625                 if (*p)
 626                         p++;
 627         }
 628         /* Ignore trailing "\*" and "\@" in @pattern. */
 629         while (*p == '\\' &&
 630                (*(p + 1) == '*' || *(p + 1) == '@'))
 631                 p += 2;
 632         return !*f && !*p;
 633  recursive:
 634         /*
 635          * The "\{" pattern is permitted only after '/' character.
 636          * This guarantees that below "*(p - 1)" is safe.
 637          * Also, the "\}" pattern is permitted only before '/' character
 638          * so that "\{" + "\}" pair will not break the "\-" operator.
 639          */
 640         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 641             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 642                 return false; /* Bad pattern. */
 643         do {
 644                 /* Compare current component with pattern. */
 645                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 646                                                  p_delimiter - 2))
 647                         break;
 648                 /* Proceed to next component. */
 649                 f = f_delimiter;
 650                 if (!*f)
 651                         break;
 652                 f++;
 653                 /* Continue comparison. */
 654                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 655                         return true;
 656                 f_delimiter = strchr(f, '/');
 657         } while (f_delimiter);
 658         return false; /* Not matched. */
 659 }
 660
 661 /**
 662  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 663  *
 664  * @filename: The filename to check.
 665  * @pattern:  The pattern to compare.
 666  *
 667  * Returns true if matches, false otherwise.
 668  *
 669  * The following patterns are available.
 670  *   \\     \ itself.
 671  *   \ooo   Octal representation of a byte.
 672  *   \*     Zero or more repetitions of characters other than '/'.
 673  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 674  *   \?     1 byte character other than '/'.
 675  *   \$     One or more repetitions of decimal digits.
 676  *   \+     1 decimal digit.
 677  *   \X     One or more repetitions of hexadecimal digits.
 678  *   \x     1 hexadecimal digit.
 679  *   \A     One or more repetitions of alphabet characters.
 680  *   \a     1 alphabet character.
 681  *
 682  *   \-     Subtraction operator.
 683  *
 684  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 685  *               /dir/dir/dir/ ).
 686  */
 687 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 688                                  const struct tomoyo_path_info *pattern)
 689 {
 690         const char *f = filename->name;
 691         const char *p = pattern->name;
 692         const int len = pattern->const_len;
 693
 694         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 695         if (!pattern->is_patterned)
 696                 return !tomoyo_pathcmp(filename, pattern);
 697         /* Don't compare directory and non-directory. */
 698         if (filename->is_dir != pattern->is_dir)
 699                 return false;
 700         /* Compare the initial length without patterns. */
 701         if (strncmp(f, p, len))
 702                 return false;
 703         f += len;
 704         p += len;
 705         return tomoyo_path_matches_pattern2(f, p);
 706 }
 707
 708 /**
 709  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 710  *
 711  * @head: Pointer to "struct tomoyo_io_buffer".
 712  * @fmt:  The printf()'s format string, followed by parameters.
 713  *
 714  * Returns true if output was written, false otherwise.
 715  *
 716  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 717  */
 718 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 719 {
 720         va_list args;
 721         int len;
 722         int pos = head->read_avail;
 723         int size = head->readbuf_size - pos;
 724
 725         if (size <= 0)
 726                 return false;
 727         va_start(args, fmt);
 728         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 729         va_end(args);
 730         if (pos + len >= head->readbuf_size)
 731                 return false;
 732         head->read_avail += len;
 733         return true;
 734 }
 735
 736 /**
 737  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 738  *
 739  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 740  *
 741  * This function uses kzalloc(), so the caller must call kfree()
 742  * if this function didn't return NULL.
 743  */
 744 static const char *tomoyo_get_exe(void)
 745 {
 746         struct mm_struct *mm = current->mm;
 747         struct vm_area_struct *vma;
 748         const char *cp = NULL;
 749
 750         if (!mm)
 751                 return NULL;
 752         down_read(&mm->mmap_sem);
 753         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 754                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 755                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 756                         break;
 757                 }
 758         }
 759         up_read(&mm->mmap_sem);
 760         return cp;
 761 }
 762
 763 /**
 764  * tomoyo_get_msg - Get warning message.
 765  *
 766  * @is_enforce: Is it enforcing mode?
 767  *
 768  * Returns "ERROR" or "WARNING".
 769  */
 770 const char *tomoyo_get_msg(const bool is_enforce)
 771 {
 772         if (is_enforce)
 773                 return "ERROR";
 774         else
 775                 return "WARNING";
 776 }
 777
 778 /**
 779  * tomoyo_check_flags - Check mode for specified functionality.
 780  *
 781  * @domain: Pointer to "struct tomoyo_domain_info".
 782  * @index:  The functionality to check mode.
 783  *
 784  * TOMOYO checks only process context.
 785  * This code disables TOMOYO's enforcement in case the function is called from
 786  * interrupt context.
 787  */
 788 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 789                                 const u8 index)
 790 {
 791         const u8 profile = domain->profile;
 792
 793         if (WARN_ON(in_interrupt()))
 794                 return 0;
 795         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 796 #if TOMOYO_MAX_PROFILES != 256
 797                 && profile < TOMOYO_MAX_PROFILES
 798 #endif
 799                 && tomoyo_profile_ptr[profile] ?
 800                 tomoyo_profile_ptr[profile]->value[index] : 0;
 801 }
 802
 803 /**
 804  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 805  *
 806  * @domain: Pointer to "struct tomoyo_domain_info".
 807  *
 808  * Returns true if domain policy violation warning should be printed to
 809  * console.
 810  */
 811 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 812 {
 813         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 814 }
 815
 816 /**
 817  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 818  *
 819  * @domain: Pointer to "struct tomoyo_domain_info".
 820  *
 821  * Returns true if the domain is not exceeded quota, false otherwise.
 822  *
 823  * Caller holds tomoyo_read_lock().
 824  */
 825 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 826 {
 827         unsigned int count = 0;
 828         struct tomoyo_acl_info *ptr;
 829
 830         if (!domain)
 831                 return true;
 832         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 833                 switch (ptr->type) {
 834                         struct tomoyo_path_acl *acl;
 835                         u32 perm;
 836                         u8 i;
 837                 case TOMOYO_TYPE_PATH_ACL:
 838                         acl = container_of(ptr, struct tomoyo_path_acl, head);
 839                         perm = acl->perm | (((u32) acl->perm_high) << 16);
 840                         for (i = 0; i < TOMOYO_MAX_PATH_OPERATION; i++)
 841                                 if (perm & (1 << i))
 842                                         count++;
 843                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
 844                                 count -= 2;
 845                         break;
 846                 case TOMOYO_TYPE_PATH2_ACL:
 847                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
 848                                 ->perm;
 849                         for (i = 0; i < TOMOYO_MAX_PATH2_OPERATION; i++)
 850                                 if (perm & (1 << i))
 851                                         count++;
 852                         break;
 853                 }
 854         }
 855         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 856                 return true;
 857         if (!domain->quota_warned) {
 858                 domain->quota_warned = true;
 859                 printk(KERN_WARNING "TOMOYO-WARNING: "
 860                        "Domain '%s' has so many ACLs to hold. "
 861                        "Stopped learning mode.\n", domain->domainname->name);
 862         }
 863         return false;
 864 }
 865
 866 /**
 867  * tomoyo_find_or_assign_new_profile - Create a new profile.
 868  *
 869  * @profile: Profile number to create.
 870  *
 871  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 872  */
 873 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 874                                                                 int profile)
 875 {
 876         static DEFINE_MUTEX(lock);
 877         struct tomoyo_profile *ptr = NULL;
 878         int i;
 879
 880         if (profile >= TOMOYO_MAX_PROFILES)
 881                 return NULL;
 882         mutex_lock(&lock);
 883         ptr = tomoyo_profile_ptr[profile];
 884         if (ptr)
 885                 goto ok;
 886         ptr = kmalloc(sizeof(*ptr), GFP_KERNEL);
 887         if (!tomoyo_memory_ok(ptr)) {
 888                 kfree(ptr);
 889                 goto ok;
 890         }
 891         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 892                 ptr->value[i] = tomoyo_control_array[i].current_value;
 893         mb(); /* Avoid out-of-order execution. */
 894         tomoyo_profile_ptr[profile] = ptr;
 895  ok:
 896         mutex_unlock(&lock);
 897         return ptr;
 898 }
 899
 900 /**
 901  * tomoyo_write_profile - Write to profile table.
 902  *
 903  * @head: Pointer to "struct tomoyo_io_buffer".
 904  *
 905  * Returns 0 on success, negative value otherwise.
 906  */
 907 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 908 {
 909         char *data = head->write_buf;
 910         unsigned int i;
 911         unsigned int value;
 912         char *cp;
 913         struct tomoyo_profile *profile;
 914         unsigned long num;
 915
 916         cp = strchr(data, '-');
 917         if (cp)
 918                 *cp = '\0';
 919         if (strict_strtoul(data, 10, &num))
 920                 return -EINVAL;
 921         if (cp)
 922                 data = cp + 1;
 923         profile = tomoyo_find_or_assign_new_profile(num);
 924         if (!profile)
 925                 return -EINVAL;
 926         cp = strchr(data, '=');
 927         if (!cp)
 928                 return -EINVAL;
 929         *cp = '\0';
 930         if (!strcmp(data, "COMMENT")) {
 931                 const struct tomoyo_path_info *old_comment = profile->comment;
 932                 profile->comment = tomoyo_get_name(cp + 1);
 933                 tomoyo_put_name(old_comment);
 934                 return 0;
 935         }
 936         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 937                 if (strcmp(data, tomoyo_control_array[i].keyword))
 938                         continue;
 939                 if (sscanf(cp + 1, "%u", &value) != 1) {
 940                         int j;
 941                         const char **modes;
 942                         switch (i) {
 943                         case TOMOYO_VERBOSE:
 944                                 modes = tomoyo_mode_2;
 945                                 break;
 946                         default:
 947                                 modes = tomoyo_mode_4;
 948                                 break;
 949                         }
 950                         for (j = 0; j < 4; j++) {
 951                                 if (strcmp(cp + 1, modes[j]))
 952                                         continue;
 953                                 value = j;
 954                                 break;
 955                         }
 956                         if (j == 4)
 957                                 return -EINVAL;
 958                 } else if (value > tomoyo_control_array[i].max_value) {
 959                         value = tomoyo_control_array[i].max_value;
 960                 }
 961                 profile->value[i] = value;
 962                 return 0;
 963         }
 964         return -EINVAL;
 965 }
 966
 967 /**
 968  * tomoyo_read_profile - Read from profile table.
 969  *
 970  * @head: Pointer to "struct tomoyo_io_buffer".
 971  *
 972  * Returns 0.
 973  */
 974 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 975 {
 976         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 977         int step;
 978
 979         if (head->read_eof)
 980                 return 0;
 981         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 982              step++) {
 983                 const u8 index = step / total;
 984                 u8 type = step % total;
 985                 const struct tomoyo_profile *profile
 986                         = tomoyo_profile_ptr[index];
 987                 head->read_step = step;
 988                 if (!profile)
 989                         continue;
 990                 if (!type) { /* Print profile' comment tag. */
 991                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
 992                                               index, profile->comment ?
 993                                               profile->comment->name : ""))
 994                                 break;
 995                         continue;
 996                 }
 997                 type--;
 998                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
 999                         const unsigned int value = profile->value[type];
1000                         const char **modes = NULL;
1001                         const char *keyword
1002                                 = tomoyo_control_array[type].keyword;
1003                         switch (tomoyo_control_array[type].max_value) {
1004                         case 3:
1005                                 modes = tomoyo_mode_4;
1006                                 break;
1007                         case 1:
1008                                 modes = tomoyo_mode_2;
1009                                 break;
1010                         }
1011                         if (modes) {
1012                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1013                                                       keyword, modes[value]))
1014                                         break;
1015                         } else {
1016                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1017                                                       keyword, value))
1018                                         break;
1019                         }
1020                 }
1021         }
1022         if (step == TOMOYO_MAX_PROFILES * total)
1023                 head->read_eof = true;
1024         return 0;
1025 }
1026
1027 /*
1028  * tomoyo_policy_manager_list is used for holding list of domainnames or
1029  * programs which are permitted to modify configuration via
1030  * /sys/kernel/security/tomoyo/ interface.
1031  *
1032  * An entry is added by
1033  *
1034  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1035  *                                        /sys/kernel/security/tomoyo/manager
1036  *  (if you want to specify by a domainname)
1037  *
1038  *  or
1039  *
1040  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1041  *  (if you want to specify by a program's location)
1042  *
1043  * and is deleted by
1044  *
1045  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1046  *                                        /sys/kernel/security/tomoyo/manager
1047  *
1048  *  or
1049  *
1050  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1051  *                                        /sys/kernel/security/tomoyo/manager
1052  *
1053  * and all entries are retrieved by
1054  *
1055  * # cat /sys/kernel/security/tomoyo/manager
1056  */
1057 LIST_HEAD(tomoyo_policy_manager_list);
1058
1059 /**
1060  * tomoyo_update_manager_entry - Add a manager entry.
1061  *
1062  * @manager:   The path to manager or the domainnamme.
1063  * @is_delete: True if it is a delete request.
1064  *
1065  * Returns 0 on success, negative value otherwise.
1066  *
1067  * Caller holds tomoyo_read_lock().
1068  */
1069 static int tomoyo_update_manager_entry(const char *manager,
1070                                        const bool is_delete)
1071 {
1072         struct tomoyo_policy_manager_entry *entry = NULL;
1073         struct tomoyo_policy_manager_entry *ptr;
1074         const struct tomoyo_path_info *saved_manager;
1075         int error = is_delete ? -ENOENT : -ENOMEM;
1076         bool is_domain = false;
1077
1078         if (tomoyo_is_domain_def(manager)) {
1079                 if (!tomoyo_is_correct_domain(manager))
1080                         return -EINVAL;
1081                 is_domain = true;
1082         } else {
1083                 if (!tomoyo_is_correct_path(manager, 1, -1, -1))
1084                         return -EINVAL;
1085         }
1086         saved_manager = tomoyo_get_name(manager);
1087         if (!saved_manager)
1088                 return -ENOMEM;
1089         if (!is_delete)
1090                 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1091         mutex_lock(&tomoyo_policy_lock);
1092         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1093                 if (ptr->manager != saved_manager)
1094                         continue;
1095                 ptr->is_deleted = is_delete;
1096                 error = 0;
1097                 break;
1098         }
1099         if (!is_delete && error && tomoyo_memory_ok(entry)) {
1100                 entry->manager = saved_manager;
1101                 saved_manager = NULL;
1102                 entry->is_domain = is_domain;
1103                 list_add_tail_rcu(&entry->list, &tomoyo_policy_manager_list);
1104                 entry = NULL;
1105                 error = 0;
1106         }
1107         mutex_unlock(&tomoyo_policy_lock);
1108         tomoyo_put_name(saved_manager);
1109         kfree(entry);
1110         return error;
1111 }
1112
1113 /**
1114  * tomoyo_write_manager_policy - Write manager policy.
1115  *
1116  * @head: Pointer to "struct tomoyo_io_buffer".
1117  *
1118  * Returns 0 on success, negative value otherwise.
1119  *
1120  * Caller holds tomoyo_read_lock().
1121  */
1122 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1123 {
1124         char *data = head->write_buf;
1125         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1126
1127         if (!strcmp(data, "manage_by_non_root")) {
1128                 tomoyo_manage_by_non_root = !is_delete;
1129                 return 0;
1130         }
1131         return tomoyo_update_manager_entry(data, is_delete);
1132 }
1133
1134 /**
1135  * tomoyo_read_manager_policy - Read manager policy.
1136  *
1137  * @head: Pointer to "struct tomoyo_io_buffer".
1138  *
1139  * Returns 0.
1140  *
1141  * Caller holds tomoyo_read_lock().
1142  */
1143 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1144 {
1145         struct list_head *pos;
1146         bool done = true;
1147
1148         if (head->read_eof)
1149                 return 0;
1150         list_for_each_cookie(pos, head->read_var2,
1151                              &tomoyo_policy_manager_list) {
1152                 struct tomoyo_policy_manager_entry *ptr;
1153                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1154                                  list);
1155                 if (ptr->is_deleted)
1156                         continue;
1157                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1158                 if (!done)
1159                         break;
1160         }
1161         head->read_eof = done;
1162         return 0;
1163 }
1164
1165 /**
1166  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1167  *
1168  * Returns true if the current process is permitted to modify policy
1169  * via /sys/kernel/security/tomoyo/ interface.
1170  *
1171  * Caller holds tomoyo_read_lock().
1172  */
1173 static bool tomoyo_is_policy_manager(void)
1174 {
1175         struct tomoyo_policy_manager_entry *ptr;
1176         const char *exe;
1177         const struct task_struct *task = current;
1178         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1179         bool found = false;
1180
1181         if (!tomoyo_policy_loaded)
1182                 return true;
1183         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1184                 return false;
1185         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1186                 if (!ptr->is_deleted && ptr->is_domain
1187                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1188                         found = true;
1189                         break;
1190                 }
1191         }
1192         if (found)
1193                 return true;
1194         exe = tomoyo_get_exe();
1195         if (!exe)
1196                 return false;
1197         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1198                 if (!ptr->is_deleted && !ptr->is_domain
1199                     && !strcmp(exe, ptr->manager->name)) {
1200                         found = true;
1201                         break;
1202                 }
1203         }
1204         if (!found) { /* Reduce error messages. */
1205                 static pid_t last_pid;
1206                 const pid_t pid = current->pid;
1207                 if (last_pid != pid) {
1208                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1209                                "update policies.\n", domainname->name, exe);
1210                         last_pid = pid;
1211                 }
1212         }
1213         kfree(exe);
1214         return found;
1215 }
1216
1217 /**
1218  * tomoyo_is_select_one - Parse select command.
1219  *
1220  * @head: Pointer to "struct tomoyo_io_buffer".
1221  * @data: String to parse.
1222  *
1223  * Returns true on success, false otherwise.
1224  *
1225  * Caller holds tomoyo_read_lock().
1226  */
1227 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1228                                  const char *data)
1229 {
1230         unsigned int pid;
1231         struct tomoyo_domain_info *domain = NULL;
1232
1233         if (sscanf(data, "pid=%u", &pid) == 1) {
1234                 struct task_struct *p;
1235                 read_lock(&tasklist_lock);
1236                 p = find_task_by_vpid(pid);
1237                 if (p)
1238                         domain = tomoyo_real_domain(p);
1239                 read_unlock(&tasklist_lock);
1240         } else if (!strncmp(data, "domain=", 7)) {
1241                 if (tomoyo_is_domain_def(data + 7))
1242                         domain = tomoyo_find_domain(data + 7);
1243         } else
1244                 return false;
1245         head->write_var1 = domain;
1246         /* Accessing read_buf is safe because head->io_sem is held. */
1247         if (!head->read_buf)
1248                 return true; /* Do nothing if open(O_WRONLY). */
1249         head->read_avail = 0;
1250         tomoyo_io_printf(head, "# select %s\n", data);
1251         head->read_single_domain = true;
1252         head->read_eof = !domain;
1253         if (domain) {
1254                 struct tomoyo_domain_info *d;
1255                 head->read_var1 = NULL;
1256                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1257                         if (d == domain)
1258                                 break;
1259                         head->read_var1 = &d->list;
1260                 }
1261                 head->read_var2 = NULL;
1262                 head->read_bit = 0;
1263                 head->read_step = 0;
1264                 if (domain->is_deleted)
1265                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1266         }
1267         return true;
1268 }
1269
1270 /**
1271  * tomoyo_delete_domain - Delete a domain.
1272  *
1273  * @domainname: The name of domain.
1274  *
1275  * Returns 0.
1276  *
1277  * Caller holds tomoyo_read_lock().
1278  */
1279 static int tomoyo_delete_domain(char *domainname)
1280 {
1281         struct tomoyo_domain_info *domain;
1282         struct tomoyo_path_info name;
1283
1284         name.name = domainname;
1285         tomoyo_fill_path_info(&name);
1286         mutex_lock(&tomoyo_policy_lock);
1287         /* Is there an active domain? */
1288         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1289                 /* Never delete tomoyo_kernel_domain */
1290                 if (domain == &tomoyo_kernel_domain)
1291                         continue;
1292                 if (domain->is_deleted ||
1293                     tomoyo_pathcmp(domain->domainname, &name))
1294                         continue;
1295                 domain->is_deleted = true;
1296                 break;
1297         }
1298         mutex_unlock(&tomoyo_policy_lock);
1299         return 0;
1300 }
1301
1302 /**
1303  * tomoyo_write_domain_policy - Write domain policy.
1304  *
1305  * @head: Pointer to "struct tomoyo_io_buffer".
1306  *
1307  * Returns 0 on success, negative value otherwise.
1308  *
1309  * Caller holds tomoyo_read_lock().
1310  */
1311 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1312 {
1313         char *data = head->write_buf;
1314         struct tomoyo_domain_info *domain = head->write_var1;
1315         bool is_delete = false;
1316         bool is_select = false;
1317         unsigned int profile;
1318
1319         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1320                 is_delete = true;
1321         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1322                 is_select = true;
1323         if (is_select && tomoyo_is_select_one(head, data))
1324                 return 0;
1325         /* Don't allow updating policies by non manager programs. */
1326         if (!tomoyo_is_policy_manager())
1327                 return -EPERM;
1328         if (tomoyo_is_domain_def(data)) {
1329                 domain = NULL;
1330                 if (is_delete)
1331                         tomoyo_delete_domain(data);
1332                 else if (is_select)
1333                         domain = tomoyo_find_domain(data);
1334                 else
1335                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1336                 head->write_var1 = domain;
1337                 return 0;
1338         }
1339         if (!domain)
1340                 return -EINVAL;
1341
1342         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1343             && profile < TOMOYO_MAX_PROFILES) {
1344                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1345                         domain->profile = (u8) profile;
1346                 return 0;
1347         }
1348         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1349                 domain->ignore_global_allow_read = !is_delete;
1350                 return 0;
1351         }
1352         return tomoyo_write_file_policy(data, domain, is_delete);
1353 }
1354
1355 /**
1356  * tomoyo_print_path_acl - Print a single path ACL entry.
1357  *
1358  * @head: Pointer to "struct tomoyo_io_buffer".
1359  * @ptr:  Pointer to "struct tomoyo_path_acl".
1360  *
1361  * Returns true on success, false otherwise.
1362  */
1363 static bool tomoyo_print_path_acl(struct tomoyo_io_buffer *head,
1364                                   struct tomoyo_path_acl *ptr)
1365 {
1366         int pos;
1367         u8 bit;
1368         const char *atmark = "";
1369         const char *filename;
1370         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1371
1372         filename = ptr->filename->name;
1373         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
1374                 const char *msg;
1375                 if (!(perm & (1 << bit)))
1376                         continue;
1377                 /* Print "read/write" instead of "read" and "write". */
1378                 if ((bit == TOMOYO_TYPE_READ || bit == TOMOYO_TYPE_WRITE)
1379                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
1380                         continue;
1381                 msg = tomoyo_path2keyword(bit);
1382                 pos = head->read_avail;
1383                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1384                                       atmark, filename))
1385                         goto out;
1386         }
1387         head->read_bit = 0;
1388         return true;
1389  out:
1390         head->read_bit = bit;
1391         head->read_avail = pos;
1392         return false;
1393 }
1394
1395 /**
1396  * tomoyo_print_path2_acl - Print a double path ACL entry.
1397  *
1398  * @head: Pointer to "struct tomoyo_io_buffer".
1399  * @ptr:  Pointer to "struct tomoyo_path2_acl".
1400  *
1401  * Returns true on success, false otherwise.
1402  */
1403 static bool tomoyo_print_path2_acl(struct tomoyo_io_buffer *head,
1404                                    struct tomoyo_path2_acl *ptr)
1405 {
1406         int pos;
1407         const char *atmark1 = "";
1408         const char *atmark2 = "";
1409         const char *filename1;
1410         const char *filename2;
1411         const u8 perm = ptr->perm;
1412         u8 bit;
1413
1414         filename1 = ptr->filename1->name;
1415         filename2 = ptr->filename2->name;
1416         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) {
1417                 const char *msg;
1418                 if (!(perm & (1 << bit)))
1419                         continue;
1420                 msg = tomoyo_path22keyword(bit);
1421                 pos = head->read_avail;
1422                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1423                                       atmark1, filename1, atmark2, filename2))
1424                         goto out;
1425         }
1426         head->read_bit = 0;
1427         return true;
1428  out:
1429         head->read_bit = bit;
1430         head->read_avail = pos;
1431         return false;
1432 }
1433
1434 /**
1435  * tomoyo_print_entry - Print an ACL entry.
1436  *
1437  * @head: Pointer to "struct tomoyo_io_buffer".
1438  * @ptr:  Pointer to an ACL entry.
1439  *
1440  * Returns true on success, false otherwise.
1441  */
1442 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1443                                struct tomoyo_acl_info *ptr)
1444 {
1445         const u8 acl_type = ptr->type;
1446
1447         if (acl_type == TOMOYO_TYPE_PATH_ACL) {
1448                 struct tomoyo_path_acl *acl
1449                         = container_of(ptr, struct tomoyo_path_acl, head);
1450                 return tomoyo_print_path_acl(head, acl);
1451         }
1452         if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
1453                 struct tomoyo_path2_acl *acl
1454                         = container_of(ptr, struct tomoyo_path2_acl, head);
1455                 return tomoyo_print_path2_acl(head, acl);
1456         }
1457         BUG(); /* This must not happen. */
1458         return false;
1459 }
1460
1461 /**
1462  * tomoyo_read_domain_policy - Read domain policy.
1463  *
1464  * @head: Pointer to "struct tomoyo_io_buffer".
1465  *
1466  * Returns 0.
1467  *
1468  * Caller holds tomoyo_read_lock().
1469  */
1470 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1471 {
1472         struct list_head *dpos;
1473         struct list_head *apos;
1474         bool done = true;
1475
1476         if (head->read_eof)
1477                 return 0;
1478         if (head->read_step == 0)
1479                 head->read_step = 1;
1480         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1481                 struct tomoyo_domain_info *domain;
1482                 const char *quota_exceeded = "";
1483                 const char *transition_failed = "";
1484                 const char *ignore_global_allow_read = "";
1485                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1486                 if (head->read_step != 1)
1487                         goto acl_loop;
1488                 if (domain->is_deleted && !head->read_single_domain)
1489                         continue;
1490                 /* Print domainname and flags. */
1491                 if (domain->quota_warned)
1492                         quota_exceeded = "quota_exceeded\n";
1493                 if (domain->transition_failed)
1494                         transition_failed = "transition_failed\n";
1495                 if (domain->ignore_global_allow_read)
1496                         ignore_global_allow_read
1497                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1498                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1499                                         "%u\n%s%s%s\n",
1500                                         domain->domainname->name,
1501                                         domain->profile, quota_exceeded,
1502                                         transition_failed,
1503                                         ignore_global_allow_read);
1504                 if (!done)
1505                         break;
1506                 head->read_step = 2;
1507 acl_loop:
1508                 if (head->read_step == 3)
1509                         goto tail_mark;
1510                 /* Print ACL entries in the domain. */
1511                 list_for_each_cookie(apos, head->read_var2,
1512                                      &domain->acl_info_list) {
1513                         struct tomoyo_acl_info *ptr
1514                                 = list_entry(apos, struct tomoyo_acl_info,
1515                                              list);
1516                         done = tomoyo_print_entry(head, ptr);
1517                         if (!done)
1518                                 break;
1519                 }
1520                 if (!done)
1521                         break;
1522                 head->read_step = 3;
1523 tail_mark:
1524                 done = tomoyo_io_printf(head, "\n");
1525                 if (!done)
1526                         break;
1527                 head->read_step = 1;
1528                 if (head->read_single_domain)
1529                         break;
1530         }
1531         head->read_eof = done;
1532         return 0;
1533 }
1534
1535 /**
1536  * tomoyo_write_domain_profile - Assign profile for specified domain.
1537  *
1538  * @head: Pointer to "struct tomoyo_io_buffer".
1539  *
1540  * Returns 0 on success, -EINVAL otherwise.
1541  *
1542  * This is equivalent to doing
1543  *
1544  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1545  *     /usr/lib/ccs/loadpolicy -d
1546  *
1547  * Caller holds tomoyo_read_lock().
1548  */
1549 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1550 {
1551         char *data = head->write_buf;
1552         char *cp = strchr(data, ' ');
1553         struct tomoyo_domain_info *domain;
1554         unsigned long profile;
1555
1556         if (!cp)
1557                 return -EINVAL;
1558         *cp = '\0';
1559         domain = tomoyo_find_domain(cp + 1);
1560         if (strict_strtoul(data, 10, &profile))
1561                 return -EINVAL;
1562         if (domain && profile < TOMOYO_MAX_PROFILES
1563             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1564                 domain->profile = (u8) profile;
1565         return 0;
1566 }
1567
1568 /**
1569  * tomoyo_read_domain_profile - Read only domainname and profile.
1570  *
1571  * @head: Pointer to "struct tomoyo_io_buffer".
1572  *
1573  * Returns list of profile number and domainname pairs.
1574  *
1575  * This is equivalent to doing
1576  *
1577  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1578  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1579  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1580  *     print $2 " " domainname; domainname = ""; } } ; '
1581  *
1582  * Caller holds tomoyo_read_lock().
1583  */
1584 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1585 {
1586         struct list_head *pos;
1587         bool done = true;
1588
1589         if (head->read_eof)
1590                 return 0;
1591         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1592                 struct tomoyo_domain_info *domain;
1593                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1594                 if (domain->is_deleted)
1595                         continue;
1596                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1597                                         domain->domainname->name);
1598                 if (!done)
1599                         break;
1600         }
1601         head->read_eof = done;
1602         return 0;
1603 }
1604
1605 /**
1606  * tomoyo_write_pid: Specify PID to obtain domainname.
1607  *
1608  * @head: Pointer to "struct tomoyo_io_buffer".
1609  *
1610  * Returns 0.
1611  */
1612 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1613 {
1614         unsigned long pid;
1615         /* No error check. */
1616         strict_strtoul(head->write_buf, 10, &pid);
1617         head->read_step = (int) pid;
1618         head->read_eof = false;
1619         return 0;
1620 }
1621
1622 /**
1623  * tomoyo_read_pid - Get domainname of the specified PID.
1624  *
1625  * @head: Pointer to "struct tomoyo_io_buffer".
1626  *
1627  * Returns the domainname which the specified PID is in on success,
1628  * empty string otherwise.
1629  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1630  * using read()/write() interface rather than sysctl() interface.
1631  */
1632 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1633 {
1634         if (head->read_avail == 0 && !head->read_eof) {
1635                 const int pid = head->read_step;
1636                 struct task_struct *p;
1637                 struct tomoyo_domain_info *domain = NULL;
1638                 read_lock(&tasklist_lock);
1639                 p = find_task_by_vpid(pid);
1640                 if (p)
1641                         domain = tomoyo_real_domain(p);
1642                 read_unlock(&tasklist_lock);
1643                 if (domain)
1644                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1645                                          domain->domainname->name);
1646                 head->read_eof = true;
1647         }
1648         return 0;
1649 }
1650
1651 /**
1652  * tomoyo_write_exception_policy - Write exception policy.
1653  *
1654  * @head: Pointer to "struct tomoyo_io_buffer".
1655  *
1656  * Returns 0 on success, negative value otherwise.
1657  *
1658  * Caller holds tomoyo_read_lock().
1659  */
1660 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1661 {
1662         char *data = head->write_buf;
1663         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1664
1665         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1666                 return tomoyo_write_domain_keeper_policy(data, false,
1667                                                          is_delete);
1668         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1669                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1670         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1671                 return tomoyo_write_domain_initializer_policy(data, false,
1672                                                               is_delete);
1673         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1674                 return tomoyo_write_domain_initializer_policy(data, true,
1675                                                               is_delete);
1676         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1677                 return tomoyo_write_alias_policy(data, is_delete);
1678         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1679                 return tomoyo_write_globally_readable_policy(data, is_delete);
1680         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1681                 return tomoyo_write_pattern_policy(data, is_delete);
1682         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1683                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1684         return -EINVAL;
1685 }
1686
1687 /**
1688  * tomoyo_read_exception_policy - Read exception policy.
1689  *
1690  * @head: Pointer to "struct tomoyo_io_buffer".
1691  *
1692  * Returns 0 on success, -EINVAL otherwise.
1693  *
1694  * Caller holds tomoyo_read_lock().
1695  */
1696 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1697 {
1698         if (!head->read_eof) {
1699                 switch (head->read_step) {
1700                 case 0:
1701                         head->read_var2 = NULL;
1702                         head->read_step = 1;
1703                 case 1:
1704                         if (!tomoyo_read_domain_keeper_policy(head))
1705                                 break;
1706                         head->read_var2 = NULL;
1707                         head->read_step = 2;
1708                 case 2:
1709                         if (!tomoyo_read_globally_readable_policy(head))
1710                                 break;
1711                         head->read_var2 = NULL;
1712                         head->read_step = 3;
1713                 case 3:
1714                         head->read_var2 = NULL;
1715                         head->read_step = 4;
1716                 case 4:
1717                         if (!tomoyo_read_domain_initializer_policy(head))
1718                                 break;
1719                         head->read_var2 = NULL;
1720                         head->read_step = 5;
1721                 case 5:
1722                         if (!tomoyo_read_alias_policy(head))
1723                                 break;
1724                         head->read_var2 = NULL;
1725                         head->read_step = 6;
1726                 case 6:
1727                         head->read_var2 = NULL;
1728                         head->read_step = 7;
1729                 case 7:
1730                         if (!tomoyo_read_file_pattern(head))
1731                                 break;
1732                         head->read_var2 = NULL;
1733                         head->read_step = 8;
1734                 case 8:
1735                         if (!tomoyo_read_no_rewrite_policy(head))
1736                                 break;
1737                         head->read_var2 = NULL;
1738                         head->read_step = 9;
1739                 case 9:
1740                         head->read_eof = true;
1741                         break;
1742                 default:
1743                         return -EINVAL;
1744                 }
1745         }
1746         return 0;
1747 }
1748
1749 /* path to policy loader */
1750 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1751
1752 /**
1753  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1754  *
1755  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1756  */
1757 static bool tomoyo_policy_loader_exists(void)
1758 {
1759         /*
1760          * Don't activate MAC if the policy loader doesn't exist.
1761          * If the initrd includes /sbin/init but real-root-dev has not
1762          * mounted on / yet, activating MAC will block the system since
1763          * policies are not loaded yet.
1764          * Thus, let do_execve() call this function everytime.
1765          */
1766         struct path path;
1767
1768         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1769                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1770                        "since %s doesn't exist.\n", tomoyo_loader);
1771                 return false;
1772         }
1773         path_put(&path);
1774         return true;
1775 }
1776
1777 /**
1778  * tomoyo_load_policy - Run external policy loader to load policy.
1779  *
1780  * @filename: The program about to start.
1781  *
1782  * This function checks whether @filename is /sbin/init , and if so
1783  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1784  * and then continues invocation of /sbin/init.
1785  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1786  * writes to /sys/kernel/security/tomoyo/ interfaces.
1787  *
1788  * Returns nothing.
1789  */
1790 void tomoyo_load_policy(const char *filename)
1791 {
1792         char *argv[2];
1793         char *envp[3];
1794
1795         if (tomoyo_policy_loaded)
1796                 return;
1797         /*
1798          * Check filename is /sbin/init or /sbin/tomoyo-start.
1799          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1800          * be passed.
1801          * You can create /sbin/tomoyo-start by
1802          * "ln -s /bin/true /sbin/tomoyo-start".
1803          */
1804         if (strcmp(filename, "/sbin/init") &&
1805             strcmp(filename, "/sbin/tomoyo-start"))
1806                 return;
1807         if (!tomoyo_policy_loader_exists())
1808                 return;
1809
1810         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1811                tomoyo_loader);
1812         argv[0] = (char *) tomoyo_loader;
1813         argv[1] = NULL;
1814         envp[0] = "HOME=/";
1815         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1816         envp[2] = NULL;
1817         call_usermodehelper(argv[0], argv, envp, 1);
1818
1819         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1820         printk(KERN_INFO "Mandatory Access Control activated.\n");
1821         tomoyo_policy_loaded = true;
1822         { /* Check all profiles currently assigned to domains are defined. */
1823                 struct tomoyo_domain_info *domain;
1824                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1825                         const u8 profile = domain->profile;
1826                         if (tomoyo_profile_ptr[profile])
1827                                 continue;
1828                         panic("Profile %u (used by '%s') not defined.\n",
1829                               profile, domain->domainname->name);
1830                 }
1831         }
1832 }
1833
1834 /**
1835  * tomoyo_read_version: Get version.
1836  *
1837  * @head: Pointer to "struct tomoyo_io_buffer".
1838  *
1839  * Returns version information.
1840  */
1841 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1842 {
1843         if (!head->read_eof) {
1844                 tomoyo_io_printf(head, "2.2.0");
1845                 head->read_eof = true;
1846         }
1847         return 0;
1848 }
1849
1850 /**
1851  * tomoyo_read_self_domain - Get the current process's domainname.
1852  *
1853  * @head: Pointer to "struct tomoyo_io_buffer".
1854  *
1855  * Returns the current process's domainname.
1856  */
1857 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1858 {
1859         if (!head->read_eof) {
1860                 /*
1861                  * tomoyo_domain()->domainname != NULL
1862                  * because every process belongs to a domain and
1863                  * the domain's name cannot be NULL.
1864                  */
1865                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1866                 head->read_eof = true;
1867         }
1868         return 0;
1869 }
1870
1871 /**
1872  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1873  *
1874  * @type: Type of interface.
1875  * @file: Pointer to "struct file".
1876  *
1877  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1878  *
1879  * Caller acquires tomoyo_read_lock().
1880  */
1881 static int tomoyo_open_control(const u8 type, struct file *file)
1882 {
1883         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_KERNEL);
1884
1885         if (!head)
1886                 return -ENOMEM;
1887         mutex_init(&head->io_sem);
1888         switch (type) {
1889         case TOMOYO_DOMAINPOLICY:
1890                 /* /sys/kernel/security/tomoyo/domain_policy */
1891                 head->write = tomoyo_write_domain_policy;
1892                 head->read = tomoyo_read_domain_policy;
1893                 break;
1894         case TOMOYO_EXCEPTIONPOLICY:
1895                 /* /sys/kernel/security/tomoyo/exception_policy */
1896                 head->write = tomoyo_write_exception_policy;
1897                 head->read = tomoyo_read_exception_policy;
1898                 break;
1899         case TOMOYO_SELFDOMAIN:
1900                 /* /sys/kernel/security/tomoyo/self_domain */
1901                 head->read = tomoyo_read_self_domain;
1902                 break;
1903         case TOMOYO_DOMAIN_STATUS:
1904                 /* /sys/kernel/security/tomoyo/.domain_status */
1905                 head->write = tomoyo_write_domain_profile;
1906                 head->read = tomoyo_read_domain_profile;
1907                 break;
1908         case TOMOYO_PROCESS_STATUS:
1909                 /* /sys/kernel/security/tomoyo/.process_status */
1910                 head->write = tomoyo_write_pid;
1911                 head->read = tomoyo_read_pid;
1912                 break;
1913         case TOMOYO_VERSION:
1914                 /* /sys/kernel/security/tomoyo/version */
1915                 head->read = tomoyo_read_version;
1916                 head->readbuf_size = 128;
1917                 break;
1918         case TOMOYO_MEMINFO:
1919                 /* /sys/kernel/security/tomoyo/meminfo */
1920                 head->write = tomoyo_write_memory_quota;
1921                 head->read = tomoyo_read_memory_counter;
1922                 head->readbuf_size = 512;
1923                 break;
1924         case TOMOYO_PROFILE:
1925                 /* /sys/kernel/security/tomoyo/profile */
1926                 head->write = tomoyo_write_profile;
1927                 head->read = tomoyo_read_profile;
1928                 break;
1929         case TOMOYO_MANAGER:
1930                 /* /sys/kernel/security/tomoyo/manager */
1931                 head->write = tomoyo_write_manager_policy;
1932                 head->read = tomoyo_read_manager_policy;
1933                 break;
1934         }
1935         if (!(file->f_mode & FMODE_READ)) {
1936                 /*
1937                  * No need to allocate read_buf since it is not opened
1938                  * for reading.
1939                  */
1940                 head->read = NULL;
1941         } else {
1942                 if (!head->readbuf_size)
1943                         head->readbuf_size = 4096 * 2;
1944                 head->read_buf = kzalloc(head->readbuf_size, GFP_KERNEL);
1945                 if (!head->read_buf) {
1946                         kfree(head);
1947                         return -ENOMEM;
1948                 }
1949         }
1950         if (!(file->f_mode & FMODE_WRITE)) {
1951                 /*
1952                  * No need to allocate write_buf since it is not opened
1953                  * for writing.
1954                  */
1955                 head->write = NULL;
1956         } else if (head->write) {
1957                 head->writebuf_size = 4096 * 2;
1958                 head->write_buf = kzalloc(head->writebuf_size, GFP_KERNEL);
1959                 if (!head->write_buf) {
1960                         kfree(head->read_buf);
1961                         kfree(head);
1962                         return -ENOMEM;
1963                 }
1964         }
1965         head->reader_idx = tomoyo_read_lock();
1966         file->private_data = head;
1967         /*
1968          * Call the handler now if the file is
1969          * /sys/kernel/security/tomoyo/self_domain
1970          * so that the user can use
1971          * cat < /sys/kernel/security/tomoyo/self_domain"
1972          * to know the current process's domainname.
1973          */
1974         if (type == TOMOYO_SELFDOMAIN)
1975                 tomoyo_read_control(file, NULL, 0);
1976         return 0;
1977 }
1978
1979 /**
1980  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1981  *
1982  * @file:       Pointer to "struct file".
1983  * @buffer:     Poiner to buffer to write to.
1984  * @buffer_len: Size of @buffer.
1985  *
1986  * Returns bytes read on success, negative value otherwise.
1987  *
1988  * Caller holds tomoyo_read_lock().
1989  */
1990 static int tomoyo_read_control(struct file *file, char __user *buffer,
1991                                const int buffer_len)
1992 {
1993         int len = 0;
1994         struct tomoyo_io_buffer *head = file->private_data;
1995         char *cp;
1996
1997         if (!head->read)
1998                 return -ENOSYS;
1999         if (mutex_lock_interruptible(&head->io_sem))
2000                 return -EINTR;
2001         /* Call the policy handler. */
2002         len = head->read(head);
2003         if (len < 0)
2004                 goto out;
2005         /* Write to buffer. */
2006         len = head->read_avail;
2007         if (len > buffer_len)
2008                 len = buffer_len;
2009         if (!len)
2010                 goto out;
2011         /* head->read_buf changes by some functions. */
2012         cp = head->read_buf;
2013         if (copy_to_user(buffer, cp, len)) {
2014                 len = -EFAULT;
2015                 goto out;
2016         }
2017         head->read_avail -= len;
2018         memmove(cp, cp + len, head->read_avail);
2019  out:
2020         mutex_unlock(&head->io_sem);
2021         return len;
2022 }
2023
2024 /**
2025  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2026  *
2027  * @file:       Pointer to "struct file".
2028  * @buffer:     Pointer to buffer to read from.
2029  * @buffer_len: Size of @buffer.
2030  *
2031  * Returns @buffer_len on success, negative value otherwise.
2032  *
2033  * Caller holds tomoyo_read_lock().
2034  */
2035 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2036                                 const int buffer_len)
2037 {
2038         struct tomoyo_io_buffer *head = file->private_data;
2039         int error = buffer_len;
2040         int avail_len = buffer_len;
2041         char *cp0 = head->write_buf;
2042
2043         if (!head->write)
2044                 return -ENOSYS;
2045         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2046                 return -EFAULT;
2047         /* Don't allow updating policies by non manager programs. */
2048         if (head->write != tomoyo_write_pid &&
2049             head->write != tomoyo_write_domain_policy &&
2050             !tomoyo_is_policy_manager())
2051                 return -EPERM;
2052         if (mutex_lock_interruptible(&head->io_sem))
2053                 return -EINTR;
2054         /* Read a line and dispatch it to the policy handler. */
2055         while (avail_len > 0) {
2056                 char c;
2057                 if (head->write_avail >= head->writebuf_size - 1) {
2058                         error = -ENOMEM;
2059                         break;
2060                 } else if (get_user(c, buffer)) {
2061                         error = -EFAULT;
2062                         break;
2063                 }
2064                 buffer++;
2065                 avail_len--;
2066                 cp0[head->write_avail++] = c;
2067                 if (c != '\n')
2068                         continue;
2069                 cp0[head->write_avail - 1] = '\0';
2070                 head->write_avail = 0;
2071                 tomoyo_normalize_line(cp0);
2072                 head->write(head);
2073         }
2074         mutex_unlock(&head->io_sem);
2075         return error;
2076 }
2077
2078 /**
2079  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2080  *
2081  * @file: Pointer to "struct file".
2082  *
2083  * Releases memory and returns 0.
2084  *
2085  * Caller looses tomoyo_read_lock().
2086  */
2087 static int tomoyo_close_control(struct file *file)
2088 {
2089         struct tomoyo_io_buffer *head = file->private_data;
2090         const bool is_write = !!head->write_buf;
2091
2092         tomoyo_read_unlock(head->reader_idx);
2093         /* Release memory used for policy I/O. */
2094         kfree(head->read_buf);
2095         head->read_buf = NULL;
2096         kfree(head->write_buf);
2097         head->write_buf = NULL;
2098         kfree(head);
2099         head = NULL;
2100         file->private_data = NULL;
2101         if (is_write)
2102                 tomoyo_run_gc();
2103         return 0;
2104 }
2105
2106 /**
2107  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2108  *
2109  * @inode: Pointer to "struct inode".
2110  * @file:  Pointer to "struct file".
2111  *
2112  * Returns 0 on success, negative value otherwise.
2113  */
2114 static int tomoyo_open(struct inode *inode, struct file *file)
2115 {
2116         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2117                 - ((u8 *) NULL);
2118         return tomoyo_open_control(key, file);
2119 }
2120
2121 /**
2122  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2123  *
2124  * @inode: Pointer to "struct inode".
2125  * @file:  Pointer to "struct file".
2126  *
2127  * Returns 0 on success, negative value otherwise.
2128  */
2129 static int tomoyo_release(struct inode *inode, struct file *file)
2130 {
2131         return tomoyo_close_control(file);
2132 }
2133
2134 /**
2135  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2136  *
2137  * @file:  Pointer to "struct file".
2138  * @buf:   Pointer to buffer.
2139  * @count: Size of @buf.
2140  * @ppos:  Unused.
2141  *
2142  * Returns bytes read on success, negative value otherwise.
2143  */
2144 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2145                            loff_t *ppos)
2146 {
2147         return tomoyo_read_control(file, buf, count);
2148 }
2149
2150 /**
2151  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2152  *
2153  * @file:  Pointer to "struct file".
2154  * @buf:   Pointer to buffer.
2155  * @count: Size of @buf.
2156  * @ppos:  Unused.
2157  *
2158  * Returns @count on success, negative value otherwise.
2159  */
2160 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2161                             size_t count, loff_t *ppos)
2162 {
2163         return tomoyo_write_control(file, buf, count);
2164 }
2165
2166 /*
2167  * tomoyo_operations is a "struct file_operations" which is used for handling
2168  * /sys/kernel/security/tomoyo/ interface.
2169  *
2170  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2171  * See tomoyo_io_buffer for internals.
2172  */
2173 static const struct file_operations tomoyo_operations = {
2174         .open    = tomoyo_open,
2175         .release = tomoyo_release,
2176         .read    = tomoyo_read,
2177         .write   = tomoyo_write,
2178 };
2179
2180 /**
2181  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2182  *
2183  * @name:   The name of the interface file.
2184  * @mode:   The permission of the interface file.
2185  * @parent: The parent directory.
2186  * @key:    Type of interface.
2187  *
2188  * Returns nothing.
2189  */
2190 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2191                                        struct dentry *parent, const u8 key)
2192 {
2193         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2194                                &tomoyo_operations);
2195 }
2196
2197 /**
2198  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2199  *
2200  * Returns 0.
2201  */
2202 static int __init tomoyo_initerface_init(void)
2203 {
2204         struct dentry *tomoyo_dir;
2205
2206         /* Don't create securityfs entries unless registered. */
2207         if (current_cred()->security != &tomoyo_kernel_domain)
2208                 return 0;
2209
2210         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2211         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2212                             TOMOYO_DOMAINPOLICY);
2213         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2214                             TOMOYO_EXCEPTIONPOLICY);
2215         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2216                             TOMOYO_SELFDOMAIN);
2217         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2218                             TOMOYO_DOMAIN_STATUS);
2219         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2220                             TOMOYO_PROCESS_STATUS);
2221         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2222                             TOMOYO_MEMINFO);
2223         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2224                             TOMOYO_PROFILE);
2225         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2226                             TOMOYO_MANAGER);
2227         tomoyo_create_entry("version",          0400, tomoyo_dir,
2228                             TOMOYO_VERSION);
2229         return 0;
2230 }
2231
2232 fs_initcall(tomoyo_initerface_init);