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                 ptr = NULL;
 890                 goto ok;
 891         }
 892         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 893                 ptr->value[i] = tomoyo_control_array[i].current_value;
 894         mb(); /* Avoid out-of-order execution. */
 895         tomoyo_profile_ptr[profile] = ptr;
 896  ok:
 897         mutex_unlock(&lock);
 898         return ptr;
 899 }
 900
 901 /**
 902  * tomoyo_write_profile - Write to profile table.
 903  *
 904  * @head: Pointer to "struct tomoyo_io_buffer".
 905  *
 906  * Returns 0 on success, negative value otherwise.
 907  */
 908 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 909 {
 910         char *data = head->write_buf;
 911         unsigned int i;
 912         unsigned int value;
 913         char *cp;
 914         struct tomoyo_profile *profile;
 915         unsigned long num;
 916
 917         cp = strchr(data, '-');
 918         if (cp)
 919                 *cp = '\0';
 920         if (strict_strtoul(data, 10, &num))
 921                 return -EINVAL;
 922         if (cp)
 923                 data = cp + 1;
 924         profile = tomoyo_find_or_assign_new_profile(num);
 925         if (!profile)
 926                 return -EINVAL;
 927         cp = strchr(data, '=');
 928         if (!cp)
 929                 return -EINVAL;
 930         *cp = '\0';
 931         if (!strcmp(data, "COMMENT")) {
 932                 const struct tomoyo_path_info *old_comment = profile->comment;
 933                 profile->comment = tomoyo_get_name(cp + 1);
 934                 tomoyo_put_name(old_comment);
 935                 return 0;
 936         }
 937         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 938                 if (strcmp(data, tomoyo_control_array[i].keyword))
 939                         continue;
 940                 if (sscanf(cp + 1, "%u", &value) != 1) {
 941                         int j;
 942                         const char **modes;
 943                         switch (i) {
 944                         case TOMOYO_VERBOSE:
 945                                 modes = tomoyo_mode_2;
 946                                 break;
 947                         default:
 948                                 modes = tomoyo_mode_4;
 949                                 break;
 950                         }
 951                         for (j = 0; j < 4; j++) {
 952                                 if (strcmp(cp + 1, modes[j]))
 953                                         continue;
 954                                 value = j;
 955                                 break;
 956                         }
 957                         if (j == 4)
 958                                 return -EINVAL;
 959                 } else if (value > tomoyo_control_array[i].max_value) {
 960                         value = tomoyo_control_array[i].max_value;
 961                 }
 962                 profile->value[i] = value;
 963                 return 0;
 964         }
 965         return -EINVAL;
 966 }
 967
 968 /**
 969  * tomoyo_read_profile - Read from profile table.
 970  *
 971  * @head: Pointer to "struct tomoyo_io_buffer".
 972  *
 973  * Returns 0.
 974  */
 975 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 976 {
 977         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 978         int step;
 979
 980         if (head->read_eof)
 981                 return 0;
 982         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 983              step++) {
 984                 const u8 index = step / total;
 985                 u8 type = step % total;
 986                 const struct tomoyo_profile *profile
 987                         = tomoyo_profile_ptr[index];
 988                 head->read_step = step;
 989                 if (!profile)
 990                         continue;
 991                 if (!type) { /* Print profile' comment tag. */
 992                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
 993                                               index, profile->comment ?
 994                                               profile->comment->name : ""))
 995                                 break;
 996                         continue;
 997                 }
 998                 type--;
 999                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1000                         const unsigned int value = profile->value[type];
1001                         const char **modes = NULL;
1002                         const char *keyword
1003                                 = tomoyo_control_array[type].keyword;
1004                         switch (tomoyo_control_array[type].max_value) {
1005                         case 3:
1006                                 modes = tomoyo_mode_4;
1007                                 break;
1008                         case 1:
1009                                 modes = tomoyo_mode_2;
1010                                 break;
1011                         }
1012                         if (modes) {
1013                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1014                                                       keyword, modes[value]))
1015                                         break;
1016                         } else {
1017                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1018                                                       keyword, value))
1019                                         break;
1020                         }
1021                 }
1022         }
1023         if (step == TOMOYO_MAX_PROFILES * total)
1024                 head->read_eof = true;
1025         return 0;
1026 }
1027
1028 /*
1029  * tomoyo_policy_manager_list is used for holding list of domainnames or
1030  * programs which are permitted to modify configuration via
1031  * /sys/kernel/security/tomoyo/ interface.
1032  *
1033  * An entry is added by
1034  *
1035  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1036  *                                        /sys/kernel/security/tomoyo/manager
1037  *  (if you want to specify by a domainname)
1038  *
1039  *  or
1040  *
1041  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1042  *  (if you want to specify by a program's location)
1043  *
1044  * and is deleted by
1045  *
1046  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1047  *                                        /sys/kernel/security/tomoyo/manager
1048  *
1049  *  or
1050  *
1051  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1052  *                                        /sys/kernel/security/tomoyo/manager
1053  *
1054  * and all entries are retrieved by
1055  *
1056  * # cat /sys/kernel/security/tomoyo/manager
1057  */
1058 LIST_HEAD(tomoyo_policy_manager_list);
1059
1060 /**
1061  * tomoyo_update_manager_entry - Add a manager entry.
1062  *
1063  * @manager:   The path to manager or the domainnamme.
1064  * @is_delete: True if it is a delete request.
1065  *
1066  * Returns 0 on success, negative value otherwise.
1067  *
1068  * Caller holds tomoyo_read_lock().
1069  */
1070 static int tomoyo_update_manager_entry(const char *manager,
1071                                        const bool is_delete)
1072 {
1073         struct tomoyo_policy_manager_entry *entry = NULL;
1074         struct tomoyo_policy_manager_entry *ptr;
1075         const struct tomoyo_path_info *saved_manager;
1076         int error = is_delete ? -ENOENT : -ENOMEM;
1077         bool is_domain = false;
1078
1079         if (tomoyo_is_domain_def(manager)) {
1080                 if (!tomoyo_is_correct_domain(manager))
1081                         return -EINVAL;
1082                 is_domain = true;
1083         } else {
1084                 if (!tomoyo_is_correct_path(manager, 1, -1, -1))
1085                         return -EINVAL;
1086         }
1087         saved_manager = tomoyo_get_name(manager);
1088         if (!saved_manager)
1089                 return -ENOMEM;
1090         if (!is_delete)
1091                 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1092         mutex_lock(&tomoyo_policy_lock);
1093         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1094                 if (ptr->manager != saved_manager)
1095                         continue;
1096                 ptr->is_deleted = is_delete;
1097                 error = 0;
1098                 break;
1099         }
1100         if (!is_delete && error && tomoyo_memory_ok(entry)) {
1101                 entry->manager = saved_manager;
1102                 saved_manager = NULL;
1103                 entry->is_domain = is_domain;
1104                 list_add_tail_rcu(&entry->list, &tomoyo_policy_manager_list);
1105                 entry = NULL;
1106                 error = 0;
1107         }
1108         mutex_unlock(&tomoyo_policy_lock);
1109         tomoyo_put_name(saved_manager);
1110         kfree(entry);
1111         return error;
1112 }
1113
1114 /**
1115  * tomoyo_write_manager_policy - Write manager policy.
1116  *
1117  * @head: Pointer to "struct tomoyo_io_buffer".
1118  *
1119  * Returns 0 on success, negative value otherwise.
1120  *
1121  * Caller holds tomoyo_read_lock().
1122  */
1123 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1124 {
1125         char *data = head->write_buf;
1126         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1127
1128         if (!strcmp(data, "manage_by_non_root")) {
1129                 tomoyo_manage_by_non_root = !is_delete;
1130                 return 0;
1131         }
1132         return tomoyo_update_manager_entry(data, is_delete);
1133 }
1134
1135 /**
1136  * tomoyo_read_manager_policy - Read manager policy.
1137  *
1138  * @head: Pointer to "struct tomoyo_io_buffer".
1139  *
1140  * Returns 0.
1141  *
1142  * Caller holds tomoyo_read_lock().
1143  */
1144 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1145 {
1146         struct list_head *pos;
1147         bool done = true;
1148
1149         if (head->read_eof)
1150                 return 0;
1151         list_for_each_cookie(pos, head->read_var2,
1152                              &tomoyo_policy_manager_list) {
1153                 struct tomoyo_policy_manager_entry *ptr;
1154                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1155                                  list);
1156                 if (ptr->is_deleted)
1157                         continue;
1158                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1159                 if (!done)
1160                         break;
1161         }
1162         head->read_eof = done;
1163         return 0;
1164 }
1165
1166 /**
1167  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1168  *
1169  * Returns true if the current process is permitted to modify policy
1170  * via /sys/kernel/security/tomoyo/ interface.
1171  *
1172  * Caller holds tomoyo_read_lock().
1173  */
1174 static bool tomoyo_is_policy_manager(void)
1175 {
1176         struct tomoyo_policy_manager_entry *ptr;
1177         const char *exe;
1178         const struct task_struct *task = current;
1179         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1180         bool found = false;
1181
1182         if (!tomoyo_policy_loaded)
1183                 return true;
1184         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1185                 return false;
1186         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1187                 if (!ptr->is_deleted && ptr->is_domain
1188                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1189                         found = true;
1190                         break;
1191                 }
1192         }
1193         if (found)
1194                 return true;
1195         exe = tomoyo_get_exe();
1196         if (!exe)
1197                 return false;
1198         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1199                 if (!ptr->is_deleted && !ptr->is_domain
1200                     && !strcmp(exe, ptr->manager->name)) {
1201                         found = true;
1202                         break;
1203                 }
1204         }
1205         if (!found) { /* Reduce error messages. */
1206                 static pid_t last_pid;
1207                 const pid_t pid = current->pid;
1208                 if (last_pid != pid) {
1209                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1210                                "update policies.\n", domainname->name, exe);
1211                         last_pid = pid;
1212                 }
1213         }
1214         kfree(exe);
1215         return found;
1216 }
1217
1218 /**
1219  * tomoyo_is_select_one - Parse select command.
1220  *
1221  * @head: Pointer to "struct tomoyo_io_buffer".
1222  * @data: String to parse.
1223  *
1224  * Returns true on success, false otherwise.
1225  *
1226  * Caller holds tomoyo_read_lock().
1227  */
1228 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1229                                  const char *data)
1230 {
1231         unsigned int pid;
1232         struct tomoyo_domain_info *domain = NULL;
1233
1234         if (sscanf(data, "pid=%u", &pid) == 1) {
1235                 struct task_struct *p;
1236                 rcu_read_lock();
1237                 read_lock(&tasklist_lock);
1238                 p = find_task_by_vpid(pid);
1239                 if (p)
1240                         domain = tomoyo_real_domain(p);
1241                 read_unlock(&tasklist_lock);
1242                 rcu_read_unlock();
1243         } else if (!strncmp(data, "domain=", 7)) {
1244                 if (tomoyo_is_domain_def(data + 7))
1245                         domain = tomoyo_find_domain(data + 7);
1246         } else
1247                 return false;
1248         head->write_var1 = domain;
1249         /* Accessing read_buf is safe because head->io_sem is held. */
1250         if (!head->read_buf)
1251                 return true; /* Do nothing if open(O_WRONLY). */
1252         head->read_avail = 0;
1253         tomoyo_io_printf(head, "# select %s\n", data);
1254         head->read_single_domain = true;
1255         head->read_eof = !domain;
1256         if (domain) {
1257                 struct tomoyo_domain_info *d;
1258                 head->read_var1 = NULL;
1259                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1260                         if (d == domain)
1261                                 break;
1262                         head->read_var1 = &d->list;
1263                 }
1264                 head->read_var2 = NULL;
1265                 head->read_bit = 0;
1266                 head->read_step = 0;
1267                 if (domain->is_deleted)
1268                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1269         }
1270         return true;
1271 }
1272
1273 /**
1274  * tomoyo_delete_domain - Delete a domain.
1275  *
1276  * @domainname: The name of domain.
1277  *
1278  * Returns 0.
1279  *
1280  * Caller holds tomoyo_read_lock().
1281  */
1282 static int tomoyo_delete_domain(char *domainname)
1283 {
1284         struct tomoyo_domain_info *domain;
1285         struct tomoyo_path_info name;
1286
1287         name.name = domainname;
1288         tomoyo_fill_path_info(&name);
1289         mutex_lock(&tomoyo_policy_lock);
1290         /* Is there an active domain? */
1291         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1292                 /* Never delete tomoyo_kernel_domain */
1293                 if (domain == &tomoyo_kernel_domain)
1294                         continue;
1295                 if (domain->is_deleted ||
1296                     tomoyo_pathcmp(domain->domainname, &name))
1297                         continue;
1298                 domain->is_deleted = true;
1299                 break;
1300         }
1301         mutex_unlock(&tomoyo_policy_lock);
1302         return 0;
1303 }
1304
1305 /**
1306  * tomoyo_write_domain_policy - Write domain policy.
1307  *
1308  * @head: Pointer to "struct tomoyo_io_buffer".
1309  *
1310  * Returns 0 on success, negative value otherwise.
1311  *
1312  * Caller holds tomoyo_read_lock().
1313  */
1314 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1315 {
1316         char *data = head->write_buf;
1317         struct tomoyo_domain_info *domain = head->write_var1;
1318         bool is_delete = false;
1319         bool is_select = false;
1320         unsigned int profile;
1321
1322         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1323                 is_delete = true;
1324         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1325                 is_select = true;
1326         if (is_select && tomoyo_is_select_one(head, data))
1327                 return 0;
1328         /* Don't allow updating policies by non manager programs. */
1329         if (!tomoyo_is_policy_manager())
1330                 return -EPERM;
1331         if (tomoyo_is_domain_def(data)) {
1332                 domain = NULL;
1333                 if (is_delete)
1334                         tomoyo_delete_domain(data);
1335                 else if (is_select)
1336                         domain = tomoyo_find_domain(data);
1337                 else
1338                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1339                 head->write_var1 = domain;
1340                 return 0;
1341         }
1342         if (!domain)
1343                 return -EINVAL;
1344
1345         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1346             && profile < TOMOYO_MAX_PROFILES) {
1347                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1348                         domain->profile = (u8) profile;
1349                 return 0;
1350         }
1351         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1352                 domain->ignore_global_allow_read = !is_delete;
1353                 return 0;
1354         }
1355         return tomoyo_write_file_policy(data, domain, is_delete);
1356 }
1357
1358 /**
1359  * tomoyo_print_path_acl - Print a single path ACL entry.
1360  *
1361  * @head: Pointer to "struct tomoyo_io_buffer".
1362  * @ptr:  Pointer to "struct tomoyo_path_acl".
1363  *
1364  * Returns true on success, false otherwise.
1365  */
1366 static bool tomoyo_print_path_acl(struct tomoyo_io_buffer *head,
1367                                   struct tomoyo_path_acl *ptr)
1368 {
1369         int pos;
1370         u8 bit;
1371         const char *atmark = "";
1372         const char *filename;
1373         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1374
1375         filename = ptr->filename->name;
1376         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
1377                 const char *msg;
1378                 if (!(perm & (1 << bit)))
1379                         continue;
1380                 /* Print "read/write" instead of "read" and "write". */
1381                 if ((bit == TOMOYO_TYPE_READ || bit == TOMOYO_TYPE_WRITE)
1382                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
1383                         continue;
1384                 msg = tomoyo_path2keyword(bit);
1385                 pos = head->read_avail;
1386                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1387                                       atmark, filename))
1388                         goto out;
1389         }
1390         head->read_bit = 0;
1391         return true;
1392  out:
1393         head->read_bit = bit;
1394         head->read_avail = pos;
1395         return false;
1396 }
1397
1398 /**
1399  * tomoyo_print_path2_acl - Print a double path ACL entry.
1400  *
1401  * @head: Pointer to "struct tomoyo_io_buffer".
1402  * @ptr:  Pointer to "struct tomoyo_path2_acl".
1403  *
1404  * Returns true on success, false otherwise.
1405  */
1406 static bool tomoyo_print_path2_acl(struct tomoyo_io_buffer *head,
1407                                    struct tomoyo_path2_acl *ptr)
1408 {
1409         int pos;
1410         const char *atmark1 = "";
1411         const char *atmark2 = "";
1412         const char *filename1;
1413         const char *filename2;
1414         const u8 perm = ptr->perm;
1415         u8 bit;
1416
1417         filename1 = ptr->filename1->name;
1418         filename2 = ptr->filename2->name;
1419         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) {
1420                 const char *msg;
1421                 if (!(perm & (1 << bit)))
1422                         continue;
1423                 msg = tomoyo_path22keyword(bit);
1424                 pos = head->read_avail;
1425                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1426                                       atmark1, filename1, atmark2, filename2))
1427                         goto out;
1428         }
1429         head->read_bit = 0;
1430         return true;
1431  out:
1432         head->read_bit = bit;
1433         head->read_avail = pos;
1434         return false;
1435 }
1436
1437 /**
1438  * tomoyo_print_entry - Print an ACL entry.
1439  *
1440  * @head: Pointer to "struct tomoyo_io_buffer".
1441  * @ptr:  Pointer to an ACL entry.
1442  *
1443  * Returns true on success, false otherwise.
1444  */
1445 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1446                                struct tomoyo_acl_info *ptr)
1447 {
1448         const u8 acl_type = ptr->type;
1449
1450         if (acl_type == TOMOYO_TYPE_PATH_ACL) {
1451                 struct tomoyo_path_acl *acl
1452                         = container_of(ptr, struct tomoyo_path_acl, head);
1453                 return tomoyo_print_path_acl(head, acl);
1454         }
1455         if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
1456                 struct tomoyo_path2_acl *acl
1457                         = container_of(ptr, struct tomoyo_path2_acl, head);
1458                 return tomoyo_print_path2_acl(head, acl);
1459         }
1460         BUG(); /* This must not happen. */
1461         return false;
1462 }
1463
1464 /**
1465  * tomoyo_read_domain_policy - Read domain policy.
1466  *
1467  * @head: Pointer to "struct tomoyo_io_buffer".
1468  *
1469  * Returns 0.
1470  *
1471  * Caller holds tomoyo_read_lock().
1472  */
1473 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1474 {
1475         struct list_head *dpos;
1476         struct list_head *apos;
1477         bool done = true;
1478
1479         if (head->read_eof)
1480                 return 0;
1481         if (head->read_step == 0)
1482                 head->read_step = 1;
1483         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1484                 struct tomoyo_domain_info *domain;
1485                 const char *quota_exceeded = "";
1486                 const char *transition_failed = "";
1487                 const char *ignore_global_allow_read = "";
1488                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1489                 if (head->read_step != 1)
1490                         goto acl_loop;
1491                 if (domain->is_deleted && !head->read_single_domain)
1492                         continue;
1493                 /* Print domainname and flags. */
1494                 if (domain->quota_warned)
1495                         quota_exceeded = "quota_exceeded\n";
1496                 if (domain->transition_failed)
1497                         transition_failed = "transition_failed\n";
1498                 if (domain->ignore_global_allow_read)
1499                         ignore_global_allow_read
1500                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1501                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1502                                         "%u\n%s%s%s\n",
1503                                         domain->domainname->name,
1504                                         domain->profile, quota_exceeded,
1505                                         transition_failed,
1506                                         ignore_global_allow_read);
1507                 if (!done)
1508                         break;
1509                 head->read_step = 2;
1510 acl_loop:
1511                 if (head->read_step == 3)
1512                         goto tail_mark;
1513                 /* Print ACL entries in the domain. */
1514                 list_for_each_cookie(apos, head->read_var2,
1515                                      &domain->acl_info_list) {
1516                         struct tomoyo_acl_info *ptr
1517                                 = list_entry(apos, struct tomoyo_acl_info,
1518                                              list);
1519                         done = tomoyo_print_entry(head, ptr);
1520                         if (!done)
1521                                 break;
1522                 }
1523                 if (!done)
1524                         break;
1525                 head->read_step = 3;
1526 tail_mark:
1527                 done = tomoyo_io_printf(head, "\n");
1528                 if (!done)
1529                         break;
1530                 head->read_step = 1;
1531                 if (head->read_single_domain)
1532                         break;
1533         }
1534         head->read_eof = done;
1535         return 0;
1536 }
1537
1538 /**
1539  * tomoyo_write_domain_profile - Assign profile for specified domain.
1540  *
1541  * @head: Pointer to "struct tomoyo_io_buffer".
1542  *
1543  * Returns 0 on success, -EINVAL otherwise.
1544  *
1545  * This is equivalent to doing
1546  *
1547  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1548  *     /usr/lib/ccs/loadpolicy -d
1549  *
1550  * Caller holds tomoyo_read_lock().
1551  */
1552 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1553 {
1554         char *data = head->write_buf;
1555         char *cp = strchr(data, ' ');
1556         struct tomoyo_domain_info *domain;
1557         unsigned long profile;
1558
1559         if (!cp)
1560                 return -EINVAL;
1561         *cp = '\0';
1562         domain = tomoyo_find_domain(cp + 1);
1563         if (strict_strtoul(data, 10, &profile))
1564                 return -EINVAL;
1565         if (domain && profile < TOMOYO_MAX_PROFILES
1566             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1567                 domain->profile = (u8) profile;
1568         return 0;
1569 }
1570
1571 /**
1572  * tomoyo_read_domain_profile - Read only domainname and profile.
1573  *
1574  * @head: Pointer to "struct tomoyo_io_buffer".
1575  *
1576  * Returns list of profile number and domainname pairs.
1577  *
1578  * This is equivalent to doing
1579  *
1580  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1581  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1582  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1583  *     print $2 " " domainname; domainname = ""; } } ; '
1584  *
1585  * Caller holds tomoyo_read_lock().
1586  */
1587 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1588 {
1589         struct list_head *pos;
1590         bool done = true;
1591
1592         if (head->read_eof)
1593                 return 0;
1594         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1595                 struct tomoyo_domain_info *domain;
1596                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1597                 if (domain->is_deleted)
1598                         continue;
1599                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1600                                         domain->domainname->name);
1601                 if (!done)
1602                         break;
1603         }
1604         head->read_eof = done;
1605         return 0;
1606 }
1607
1608 /**
1609  * tomoyo_write_pid: Specify PID to obtain domainname.
1610  *
1611  * @head: Pointer to "struct tomoyo_io_buffer".
1612  *
1613  * Returns 0.
1614  */
1615 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1616 {
1617         unsigned long pid;
1618         /* No error check. */
1619         strict_strtoul(head->write_buf, 10, &pid);
1620         head->read_step = (int) pid;
1621         head->read_eof = false;
1622         return 0;
1623 }
1624
1625 /**
1626  * tomoyo_read_pid - Get domainname of the specified PID.
1627  *
1628  * @head: Pointer to "struct tomoyo_io_buffer".
1629  *
1630  * Returns the domainname which the specified PID is in on success,
1631  * empty string otherwise.
1632  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1633  * using read()/write() interface rather than sysctl() interface.
1634  */
1635 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1636 {
1637         if (head->read_avail == 0 && !head->read_eof) {
1638                 const int pid = head->read_step;
1639                 struct task_struct *p;
1640                 struct tomoyo_domain_info *domain = NULL;
1641                 rcu_read_lock();
1642                 read_lock(&tasklist_lock);
1643                 p = find_task_by_vpid(pid);
1644                 if (p)
1645                         domain = tomoyo_real_domain(p);
1646                 read_unlock(&tasklist_lock);
1647                 rcu_read_unlock();
1648                 if (domain)
1649                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1650                                          domain->domainname->name);
1651                 head->read_eof = true;
1652         }
1653         return 0;
1654 }
1655
1656 /**
1657  * tomoyo_write_exception_policy - Write exception policy.
1658  *
1659  * @head: Pointer to "struct tomoyo_io_buffer".
1660  *
1661  * Returns 0 on success, negative value otherwise.
1662  *
1663  * Caller holds tomoyo_read_lock().
1664  */
1665 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1666 {
1667         char *data = head->write_buf;
1668         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1669
1670         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1671                 return tomoyo_write_domain_keeper_policy(data, false,
1672                                                          is_delete);
1673         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1674                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1675         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1676                 return tomoyo_write_domain_initializer_policy(data, false,
1677                                                               is_delete);
1678         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1679                 return tomoyo_write_domain_initializer_policy(data, true,
1680                                                               is_delete);
1681         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1682                 return tomoyo_write_alias_policy(data, is_delete);
1683         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1684                 return tomoyo_write_globally_readable_policy(data, is_delete);
1685         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1686                 return tomoyo_write_pattern_policy(data, is_delete);
1687         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1688                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1689         return -EINVAL;
1690 }
1691
1692 /**
1693  * tomoyo_read_exception_policy - Read exception policy.
1694  *
1695  * @head: Pointer to "struct tomoyo_io_buffer".
1696  *
1697  * Returns 0 on success, -EINVAL otherwise.
1698  *
1699  * Caller holds tomoyo_read_lock().
1700  */
1701 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1702 {
1703         if (!head->read_eof) {
1704                 switch (head->read_step) {
1705                 case 0:
1706                         head->read_var2 = NULL;
1707                         head->read_step = 1;
1708                 case 1:
1709                         if (!tomoyo_read_domain_keeper_policy(head))
1710                                 break;
1711                         head->read_var2 = NULL;
1712                         head->read_step = 2;
1713                 case 2:
1714                         if (!tomoyo_read_globally_readable_policy(head))
1715                                 break;
1716                         head->read_var2 = NULL;
1717                         head->read_step = 3;
1718                 case 3:
1719                         head->read_var2 = NULL;
1720                         head->read_step = 4;
1721                 case 4:
1722                         if (!tomoyo_read_domain_initializer_policy(head))
1723                                 break;
1724                         head->read_var2 = NULL;
1725                         head->read_step = 5;
1726                 case 5:
1727                         if (!tomoyo_read_alias_policy(head))
1728                                 break;
1729                         head->read_var2 = NULL;
1730                         head->read_step = 6;
1731                 case 6:
1732                         head->read_var2 = NULL;
1733                         head->read_step = 7;
1734                 case 7:
1735                         if (!tomoyo_read_file_pattern(head))
1736                                 break;
1737                         head->read_var2 = NULL;
1738                         head->read_step = 8;
1739                 case 8:
1740                         if (!tomoyo_read_no_rewrite_policy(head))
1741                                 break;
1742                         head->read_var2 = NULL;
1743                         head->read_step = 9;
1744                 case 9:
1745                         head->read_eof = true;
1746                         break;
1747                 default:
1748                         return -EINVAL;
1749                 }
1750         }
1751         return 0;
1752 }
1753
1754 /* path to policy loader */
1755 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1756
1757 /**
1758  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1759  *
1760  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1761  */
1762 static bool tomoyo_policy_loader_exists(void)
1763 {
1764         /*
1765          * Don't activate MAC if the policy loader doesn't exist.
1766          * If the initrd includes /sbin/init but real-root-dev has not
1767          * mounted on / yet, activating MAC will block the system since
1768          * policies are not loaded yet.
1769          * Thus, let do_execve() call this function everytime.
1770          */
1771         struct path path;
1772
1773         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1774                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1775                        "since %s doesn't exist.\n", tomoyo_loader);
1776                 return false;
1777         }
1778         path_put(&path);
1779         return true;
1780 }
1781
1782 /**
1783  * tomoyo_load_policy - Run external policy loader to load policy.
1784  *
1785  * @filename: The program about to start.
1786  *
1787  * This function checks whether @filename is /sbin/init , and if so
1788  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1789  * and then continues invocation of /sbin/init.
1790  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1791  * writes to /sys/kernel/security/tomoyo/ interfaces.
1792  *
1793  * Returns nothing.
1794  */
1795 void tomoyo_load_policy(const char *filename)
1796 {
1797         char *argv[2];
1798         char *envp[3];
1799
1800         if (tomoyo_policy_loaded)
1801                 return;
1802         /*
1803          * Check filename is /sbin/init or /sbin/tomoyo-start.
1804          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1805          * be passed.
1806          * You can create /sbin/tomoyo-start by
1807          * "ln -s /bin/true /sbin/tomoyo-start".
1808          */
1809         if (strcmp(filename, "/sbin/init") &&
1810             strcmp(filename, "/sbin/tomoyo-start"))
1811                 return;
1812         if (!tomoyo_policy_loader_exists())
1813                 return;
1814
1815         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1816                tomoyo_loader);
1817         argv[0] = (char *) tomoyo_loader;
1818         argv[1] = NULL;
1819         envp[0] = "HOME=/";
1820         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1821         envp[2] = NULL;
1822         call_usermodehelper(argv[0], argv, envp, 1);
1823
1824         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1825         printk(KERN_INFO "Mandatory Access Control activated.\n");
1826         tomoyo_policy_loaded = true;
1827         { /* Check all profiles currently assigned to domains are defined. */
1828                 struct tomoyo_domain_info *domain;
1829                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1830                         const u8 profile = domain->profile;
1831                         if (tomoyo_profile_ptr[profile])
1832                                 continue;
1833                         panic("Profile %u (used by '%s') not defined.\n",
1834                               profile, domain->domainname->name);
1835                 }
1836         }
1837 }
1838
1839 /**
1840  * tomoyo_read_version: Get version.
1841  *
1842  * @head: Pointer to "struct tomoyo_io_buffer".
1843  *
1844  * Returns version information.
1845  */
1846 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1847 {
1848         if (!head->read_eof) {
1849                 tomoyo_io_printf(head, "2.2.0");
1850                 head->read_eof = true;
1851         }
1852         return 0;
1853 }
1854
1855 /**
1856  * tomoyo_read_self_domain - Get the current process's domainname.
1857  *
1858  * @head: Pointer to "struct tomoyo_io_buffer".
1859  *
1860  * Returns the current process's domainname.
1861  */
1862 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1863 {
1864         if (!head->read_eof) {
1865                 /*
1866                  * tomoyo_domain()->domainname != NULL
1867                  * because every process belongs to a domain and
1868                  * the domain's name cannot be NULL.
1869                  */
1870                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1871                 head->read_eof = true;
1872         }
1873         return 0;
1874 }
1875
1876 /**
1877  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1878  *
1879  * @type: Type of interface.
1880  * @file: Pointer to "struct file".
1881  *
1882  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1883  *
1884  * Caller acquires tomoyo_read_lock().
1885  */
1886 static int tomoyo_open_control(const u8 type, struct file *file)
1887 {
1888         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_KERNEL);
1889
1890         if (!head)
1891                 return -ENOMEM;
1892         mutex_init(&head->io_sem);
1893         switch (type) {
1894         case TOMOYO_DOMAINPOLICY:
1895                 /* /sys/kernel/security/tomoyo/domain_policy */
1896                 head->write = tomoyo_write_domain_policy;
1897                 head->read = tomoyo_read_domain_policy;
1898                 break;
1899         case TOMOYO_EXCEPTIONPOLICY:
1900                 /* /sys/kernel/security/tomoyo/exception_policy */
1901                 head->write = tomoyo_write_exception_policy;
1902                 head->read = tomoyo_read_exception_policy;
1903                 break;
1904         case TOMOYO_SELFDOMAIN:
1905                 /* /sys/kernel/security/tomoyo/self_domain */
1906                 head->read = tomoyo_read_self_domain;
1907                 break;
1908         case TOMOYO_DOMAIN_STATUS:
1909                 /* /sys/kernel/security/tomoyo/.domain_status */
1910                 head->write = tomoyo_write_domain_profile;
1911                 head->read = tomoyo_read_domain_profile;
1912                 break;
1913         case TOMOYO_PROCESS_STATUS:
1914                 /* /sys/kernel/security/tomoyo/.process_status */
1915                 head->write = tomoyo_write_pid;
1916                 head->read = tomoyo_read_pid;
1917                 break;
1918         case TOMOYO_VERSION:
1919                 /* /sys/kernel/security/tomoyo/version */
1920                 head->read = tomoyo_read_version;
1921                 head->readbuf_size = 128;
1922                 break;
1923         case TOMOYO_MEMINFO:
1924                 /* /sys/kernel/security/tomoyo/meminfo */
1925                 head->write = tomoyo_write_memory_quota;
1926                 head->read = tomoyo_read_memory_counter;
1927                 head->readbuf_size = 512;
1928                 break;
1929         case TOMOYO_PROFILE:
1930                 /* /sys/kernel/security/tomoyo/profile */
1931                 head->write = tomoyo_write_profile;
1932                 head->read = tomoyo_read_profile;
1933                 break;
1934         case TOMOYO_MANAGER:
1935                 /* /sys/kernel/security/tomoyo/manager */
1936                 head->write = tomoyo_write_manager_policy;
1937                 head->read = tomoyo_read_manager_policy;
1938                 break;
1939         }
1940         if (!(file->f_mode & FMODE_READ)) {
1941                 /*
1942                  * No need to allocate read_buf since it is not opened
1943                  * for reading.
1944                  */
1945                 head->read = NULL;
1946         } else {
1947                 if (!head->readbuf_size)
1948                         head->readbuf_size = 4096 * 2;
1949                 head->read_buf = kzalloc(head->readbuf_size, GFP_KERNEL);
1950                 if (!head->read_buf) {
1951                         kfree(head);
1952                         return -ENOMEM;
1953                 }
1954         }
1955         if (!(file->f_mode & FMODE_WRITE)) {
1956                 /*
1957                  * No need to allocate write_buf since it is not opened
1958                  * for writing.
1959                  */
1960                 head->write = NULL;
1961         } else if (head->write) {
1962                 head->writebuf_size = 4096 * 2;
1963                 head->write_buf = kzalloc(head->writebuf_size, GFP_KERNEL);
1964                 if (!head->write_buf) {
1965                         kfree(head->read_buf);
1966                         kfree(head);
1967                         return -ENOMEM;
1968                 }
1969         }
1970         head->reader_idx = tomoyo_read_lock();
1971         file->private_data = head;
1972         /*
1973          * Call the handler now if the file is
1974          * /sys/kernel/security/tomoyo/self_domain
1975          * so that the user can use
1976          * cat < /sys/kernel/security/tomoyo/self_domain"
1977          * to know the current process's domainname.
1978          */
1979         if (type == TOMOYO_SELFDOMAIN)
1980                 tomoyo_read_control(file, NULL, 0);
1981         return 0;
1982 }
1983
1984 /**
1985  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1986  *
1987  * @file:       Pointer to "struct file".
1988  * @buffer:     Poiner to buffer to write to.
1989  * @buffer_len: Size of @buffer.
1990  *
1991  * Returns bytes read on success, negative value otherwise.
1992  *
1993  * Caller holds tomoyo_read_lock().
1994  */
1995 static int tomoyo_read_control(struct file *file, char __user *buffer,
1996                                const int buffer_len)
1997 {
1998         int len = 0;
1999         struct tomoyo_io_buffer *head = file->private_data;
2000         char *cp;
2001
2002         if (!head->read)
2003                 return -ENOSYS;
2004         if (mutex_lock_interruptible(&head->io_sem))
2005                 return -EINTR;
2006         /* Call the policy handler. */
2007         len = head->read(head);
2008         if (len < 0)
2009                 goto out;
2010         /* Write to buffer. */
2011         len = head->read_avail;
2012         if (len > buffer_len)
2013                 len = buffer_len;
2014         if (!len)
2015                 goto out;
2016         /* head->read_buf changes by some functions. */
2017         cp = head->read_buf;
2018         if (copy_to_user(buffer, cp, len)) {
2019                 len = -EFAULT;
2020                 goto out;
2021         }
2022         head->read_avail -= len;
2023         memmove(cp, cp + len, head->read_avail);
2024  out:
2025         mutex_unlock(&head->io_sem);
2026         return len;
2027 }
2028
2029 /**
2030  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2031  *
2032  * @file:       Pointer to "struct file".
2033  * @buffer:     Pointer to buffer to read from.
2034  * @buffer_len: Size of @buffer.
2035  *
2036  * Returns @buffer_len on success, negative value otherwise.
2037  *
2038  * Caller holds tomoyo_read_lock().
2039  */
2040 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2041                                 const int buffer_len)
2042 {
2043         struct tomoyo_io_buffer *head = file->private_data;
2044         int error = buffer_len;
2045         int avail_len = buffer_len;
2046         char *cp0 = head->write_buf;
2047
2048         if (!head->write)
2049                 return -ENOSYS;
2050         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2051                 return -EFAULT;
2052         /* Don't allow updating policies by non manager programs. */
2053         if (head->write != tomoyo_write_pid &&
2054             head->write != tomoyo_write_domain_policy &&
2055             !tomoyo_is_policy_manager())
2056                 return -EPERM;
2057         if (mutex_lock_interruptible(&head->io_sem))
2058                 return -EINTR;
2059         /* Read a line and dispatch it to the policy handler. */
2060         while (avail_len > 0) {
2061                 char c;
2062                 if (head->write_avail >= head->writebuf_size - 1) {
2063                         error = -ENOMEM;
2064                         break;
2065                 } else if (get_user(c, buffer)) {
2066                         error = -EFAULT;
2067                         break;
2068                 }
2069                 buffer++;
2070                 avail_len--;
2071                 cp0[head->write_avail++] = c;
2072                 if (c != '\n')
2073                         continue;
2074                 cp0[head->write_avail - 1] = '\0';
2075                 head->write_avail = 0;
2076                 tomoyo_normalize_line(cp0);
2077                 head->write(head);
2078         }
2079         mutex_unlock(&head->io_sem);
2080         return error;
2081 }
2082
2083 /**
2084  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2085  *
2086  * @file: Pointer to "struct file".
2087  *
2088  * Releases memory and returns 0.
2089  *
2090  * Caller looses tomoyo_read_lock().
2091  */
2092 static int tomoyo_close_control(struct file *file)
2093 {
2094         struct tomoyo_io_buffer *head = file->private_data;
2095         const bool is_write = !!head->write_buf;
2096
2097         tomoyo_read_unlock(head->reader_idx);
2098         /* Release memory used for policy I/O. */
2099         kfree(head->read_buf);
2100         head->read_buf = NULL;
2101         kfree(head->write_buf);
2102         head->write_buf = NULL;
2103         kfree(head);
2104         head = NULL;
2105         file->private_data = NULL;
2106         if (is_write)
2107                 tomoyo_run_gc();
2108         return 0;
2109 }
2110
2111 /**
2112  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2113  *
2114  * @inode: Pointer to "struct inode".
2115  * @file:  Pointer to "struct file".
2116  *
2117  * Returns 0 on success, negative value otherwise.
2118  */
2119 static int tomoyo_open(struct inode *inode, struct file *file)
2120 {
2121         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2122                 - ((u8 *) NULL);
2123         return tomoyo_open_control(key, file);
2124 }
2125
2126 /**
2127  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2128  *
2129  * @inode: Pointer to "struct inode".
2130  * @file:  Pointer to "struct file".
2131  *
2132  * Returns 0 on success, negative value otherwise.
2133  */
2134 static int tomoyo_release(struct inode *inode, struct file *file)
2135 {
2136         return tomoyo_close_control(file);
2137 }
2138
2139 /**
2140  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2141  *
2142  * @file:  Pointer to "struct file".
2143  * @buf:   Pointer to buffer.
2144  * @count: Size of @buf.
2145  * @ppos:  Unused.
2146  *
2147  * Returns bytes read on success, negative value otherwise.
2148  */
2149 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2150                            loff_t *ppos)
2151 {
2152         return tomoyo_read_control(file, buf, count);
2153 }
2154
2155 /**
2156  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2157  *
2158  * @file:  Pointer to "struct file".
2159  * @buf:   Pointer to buffer.
2160  * @count: Size of @buf.
2161  * @ppos:  Unused.
2162  *
2163  * Returns @count on success, negative value otherwise.
2164  */
2165 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2166                             size_t count, loff_t *ppos)
2167 {
2168         return tomoyo_write_control(file, buf, count);
2169 }
2170
2171 /*
2172  * tomoyo_operations is a "struct file_operations" which is used for handling
2173  * /sys/kernel/security/tomoyo/ interface.
2174  *
2175  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2176  * See tomoyo_io_buffer for internals.
2177  */
2178 static const struct file_operations tomoyo_operations = {
2179         .open    = tomoyo_open,
2180         .release = tomoyo_release,
2181         .read    = tomoyo_read,
2182         .write   = tomoyo_write,
2183 };
2184
2185 /**
2186  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2187  *
2188  * @name:   The name of the interface file.
2189  * @mode:   The permission of the interface file.
2190  * @parent: The parent directory.
2191  * @key:    Type of interface.
2192  *
2193  * Returns nothing.
2194  */
2195 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2196                                        struct dentry *parent, const u8 key)
2197 {
2198         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2199                                &tomoyo_operations);
2200 }
2201
2202 /**
2203  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2204  *
2205  * Returns 0.
2206  */
2207 static int __init tomoyo_initerface_init(void)
2208 {
2209         struct dentry *tomoyo_dir;
2210
2211         /* Don't create securityfs entries unless registered. */
2212         if (current_cred()->security != &tomoyo_kernel_domain)
2213                 return 0;
2214
2215         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2216         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2217                             TOMOYO_DOMAINPOLICY);
2218         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2219                             TOMOYO_EXCEPTIONPOLICY);
2220         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2221                             TOMOYO_SELFDOMAIN);
2222         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2223                             TOMOYO_DOMAIN_STATUS);
2224         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2225                             TOMOYO_PROCESS_STATUS);
2226         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2227                             TOMOYO_MEMINFO);
2228         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2229                             TOMOYO_PROFILE);
2230         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2231                             TOMOYO_MANAGER);
2232         tomoyo_create_entry("version",          0400, tomoyo_dir,
2233                             TOMOYO_VERSION);
2234         return 0;
2235 }
2236
2237 fs_initcall(tomoyo_initerface_init);