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   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  * @function:     The name of function calling me.
 183  *
 184  * Check whether the given filename follows the naming rules.
 185  * Returns true if @filename follows the naming rules, false otherwise.
 186  */
 187 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 188                             const s8 pattern_type, const s8 end_type,
 189                             const char *function)
 190 {
 191         const char *const start = filename;
 192         bool in_repetition = false;
 193         bool contains_pattern = false;
 194         unsigned char c;
 195         unsigned char d;
 196         unsigned char e;
 197         const char *original_filename = filename;
 198
 199         if (!filename)
 200                 goto out;
 201         c = *filename;
 202         if (start_type == 1) { /* Must start with '/' */
 203                 if (c != '/')
 204                         goto out;
 205         } else if (start_type == -1) { /* Must not start with '/' */
 206                 if (c == '/')
 207                         goto out;
 208         }
 209         if (c)
 210                 c = *(filename + strlen(filename) - 1);
 211         if (end_type == 1) { /* Must end with '/' */
 212                 if (c != '/')
 213                         goto out;
 214         } else if (end_type == -1) { /* Must not end with '/' */
 215                 if (c == '/')
 216                         goto out;
 217         }
 218         while (1) {
 219                 c = *filename++;
 220                 if (!c)
 221                         break;
 222                 if (c == '\\') {
 223                         c = *filename++;
 224                         switch (c) {
 225                         case '\\':  /* "\\" */
 226                                 continue;
 227                         case '$':   /* "\$" */
 228                         case '+':   /* "\+" */
 229                         case '?':   /* "\?" */
 230                         case '*':   /* "\*" */
 231                         case '@':   /* "\@" */
 232                         case 'x':   /* "\x" */
 233                         case 'X':   /* "\X" */
 234                         case 'a':   /* "\a" */
 235                         case 'A':   /* "\A" */
 236                         case '-':   /* "\-" */
 237                                 if (pattern_type == -1)
 238                                         break; /* Must not contain pattern */
 239                                 contains_pattern = true;
 240                                 continue;
 241                         case '{':   /* "/\{" */
 242                                 if (filename - 3 < start ||
 243                                     *(filename - 3) != '/')
 244                                         break;
 245                                 if (pattern_type == -1)
 246                                         break; /* Must not contain pattern */
 247                                 contains_pattern = true;
 248                                 in_repetition = true;
 249                                 continue;
 250                         case '}':   /* "\}/" */
 251                                 if (*filename != '/')
 252                                         break;
 253                                 if (!in_repetition)
 254                                         break;
 255                                 in_repetition = false;
 256                                 continue;
 257                         case '0':   /* "\ooo" */
 258                         case '1':
 259                         case '2':
 260                         case '3':
 261                                 d = *filename++;
 262                                 if (d < '0' || d > '7')
 263                                         break;
 264                                 e = *filename++;
 265                                 if (e < '0' || e > '7')
 266                                         break;
 267                                 c = tomoyo_make_byte(c, d, e);
 268                                 if (tomoyo_is_invalid(c))
 269                                         continue; /* pattern is not \000 */
 270                         }
 271                         goto out;
 272                 } else if (in_repetition && c == '/') {
 273                         goto out;
 274                 } else if (tomoyo_is_invalid(c)) {
 275                         goto out;
 276                 }
 277         }
 278         if (pattern_type == 1) { /* Must contain pattern */
 279                 if (!contains_pattern)
 280                         goto out;
 281         }
 282         if (in_repetition)
 283                 goto out;
 284         return true;
 285  out:
 286         printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function,
 287                original_filename);
 288         return false;
 289 }
 290
 291 /**
 292  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 293  * @domainname:   The domainname to check.
 294  * @function:     The name of function calling me.
 295  *
 296  * Returns true if @domainname follows the naming rules, false otherwise.
 297  */
 298 bool tomoyo_is_correct_domain(const unsigned char *domainname,
 299                               const char *function)
 300 {
 301         unsigned char c;
 302         unsigned char d;
 303         unsigned char e;
 304         const char *org_domainname = domainname;
 305
 306         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 307                                    TOMOYO_ROOT_NAME_LEN))
 308                 goto out;
 309         domainname += TOMOYO_ROOT_NAME_LEN;
 310         if (!*domainname)
 311                 return true;
 312         do {
 313                 if (*domainname++ != ' ')
 314                         goto out;
 315                 if (*domainname++ != '/')
 316                         goto out;
 317                 while ((c = *domainname) != '\0' && c != ' ') {
 318                         domainname++;
 319                         if (c == '\\') {
 320                                 c = *domainname++;
 321                                 switch ((c)) {
 322                                 case '\\':  /* "\\" */
 323                                         continue;
 324                                 case '0':   /* "\ooo" */
 325                                 case '1':
 326                                 case '2':
 327                                 case '3':
 328                                         d = *domainname++;
 329                                         if (d < '0' || d > '7')
 330                                                 break;
 331                                         e = *domainname++;
 332                                         if (e < '0' || e > '7')
 333                                                 break;
 334                                         c = tomoyo_make_byte(c, d, e);
 335                                         if (tomoyo_is_invalid(c))
 336                                                 /* pattern is not \000 */
 337                                                 continue;
 338                                 }
 339                                 goto out;
 340                         } else if (tomoyo_is_invalid(c)) {
 341                                 goto out;
 342                         }
 343                 }
 344         } while (*domainname);
 345         return true;
 346  out:
 347         printk(KERN_DEBUG "%s: Invalid domainname '%s'\n", function,
 348                org_domainname);
 349         return false;
 350 }
 351
 352 /**
 353  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 354  *
 355  * @buffer: The token to check.
 356  *
 357  * Returns true if @buffer possibly be a domainname, false otherwise.
 358  */
 359 bool tomoyo_is_domain_def(const unsigned char *buffer)
 360 {
 361         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 362 }
 363
 364 /**
 365  * tomoyo_find_domain - Find a domain by the given name.
 366  *
 367  * @domainname: The domainname to find.
 368  *
 369  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 370  *
 371  * Caller holds tomoyo_read_lock().
 372  */
 373 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 374 {
 375         struct tomoyo_domain_info *domain;
 376         struct tomoyo_path_info name;
 377
 378         name.name = domainname;
 379         tomoyo_fill_path_info(&name);
 380         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 381                 if (!domain->is_deleted &&
 382                     !tomoyo_pathcmp(&name, domain->domainname))
 383                         return domain;
 384         }
 385         return NULL;
 386 }
 387
 388 /**
 389  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 390  *
 391  * @filename: The string to evaluate.
 392  *
 393  * Returns the initial length without a pattern in @filename.
 394  */
 395 static int tomoyo_const_part_length(const char *filename)
 396 {
 397         char c;
 398         int len = 0;
 399
 400         if (!filename)
 401                 return 0;
 402         while ((c = *filename++) != '\0') {
 403                 if (c != '\\') {
 404                         len++;
 405                         continue;
 406                 }
 407                 c = *filename++;
 408                 switch (c) {
 409                 case '\\':  /* "\\" */
 410                         len += 2;
 411                         continue;
 412                 case '0':   /* "\ooo" */
 413                 case '1':
 414                 case '2':
 415                 case '3':
 416                         c = *filename++;
 417                         if (c < '0' || c > '7')
 418                                 break;
 419                         c = *filename++;
 420                         if (c < '0' || c > '7')
 421                                 break;
 422                         len += 4;
 423                         continue;
 424                 }
 425                 break;
 426         }
 427         return len;
 428 }
 429
 430 /**
 431  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 432  *
 433  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 434  *
 435  * The caller sets "struct tomoyo_path_info"->name.
 436  */
 437 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 438 {
 439         const char *name = ptr->name;
 440         const int len = strlen(name);
 441
 442         ptr->const_len = tomoyo_const_part_length(name);
 443         ptr->is_dir = len && (name[len - 1] == '/');
 444         ptr->is_patterned = (ptr->const_len < len);
 445         ptr->hash = full_name_hash(name, len);
 446 }
 447
 448 /**
 449  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
 450  * and "\-" pattern.
 451  *
 452  * @filename:     The start of string to check.
 453  * @filename_end: The end of string to check.
 454  * @pattern:      The start of pattern to compare.
 455  * @pattern_end:  The end of pattern to compare.
 456  *
 457  * Returns true if @filename matches @pattern, false otherwise.
 458  */
 459 static bool tomoyo_file_matches_pattern2(const char *filename,
 460                                          const char *filename_end,
 461                                          const char *pattern,
 462                                          const char *pattern_end)
 463 {
 464         while (filename < filename_end && pattern < pattern_end) {
 465                 char c;
 466                 if (*pattern != '\\') {
 467                         if (*filename++ != *pattern++)
 468                                 return false;
 469                         continue;
 470                 }
 471                 c = *filename;
 472                 pattern++;
 473                 switch (*pattern) {
 474                         int i;
 475                         int j;
 476                 case '?':
 477                         if (c == '/') {
 478                                 return false;
 479                         } else if (c == '\\') {
 480                                 if (filename[1] == '\\')
 481                                         filename++;
 482                                 else if (tomoyo_is_byte_range(filename + 1))
 483                                         filename += 3;
 484                                 else
 485                                         return false;
 486                         }
 487                         break;
 488                 case '\\':
 489                         if (c != '\\')
 490                                 return false;
 491                         if (*++filename != '\\')
 492                                 return false;
 493                         break;
 494                 case '+':
 495                         if (!isdigit(c))
 496                                 return false;
 497                         break;
 498                 case 'x':
 499                         if (!isxdigit(c))
 500                                 return false;
 501                         break;
 502                 case 'a':
 503                         if (!tomoyo_is_alphabet_char(c))
 504                                 return false;
 505                         break;
 506                 case '0':
 507                 case '1':
 508                 case '2':
 509                 case '3':
 510                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 511                             && strncmp(filename + 1, pattern, 3) == 0) {
 512                                 filename += 3;
 513                                 pattern += 2;
 514                                 break;
 515                         }
 516                         return false; /* Not matched. */
 517                 case '*':
 518                 case '@':
 519                         for (i = 0; i <= filename_end - filename; i++) {
 520                                 if (tomoyo_file_matches_pattern2(
 521                                                     filename + i, filename_end,
 522                                                     pattern + 1, pattern_end))
 523                                         return true;
 524                                 c = filename[i];
 525                                 if (c == '.' && *pattern == '@')
 526                                         break;
 527                                 if (c != '\\')
 528                                         continue;
 529                                 if (filename[i + 1] == '\\')
 530                                         i++;
 531                                 else if (tomoyo_is_byte_range(filename + i + 1))
 532                                         i += 3;
 533                                 else
 534                                         break; /* Bad pattern. */
 535                         }
 536                         return false; /* Not matched. */
 537                 default:
 538                         j = 0;
 539                         c = *pattern;
 540                         if (c == '$') {
 541                                 while (isdigit(filename[j]))
 542                                         j++;
 543                         } else if (c == 'X') {
 544                                 while (isxdigit(filename[j]))
 545                                         j++;
 546                         } else if (c == 'A') {
 547                                 while (tomoyo_is_alphabet_char(filename[j]))
 548                                         j++;
 549                         }
 550                         for (i = 1; i <= j; i++) {
 551                                 if (tomoyo_file_matches_pattern2(
 552                                                     filename + i, filename_end,
 553                                                     pattern + 1, pattern_end))
 554                                         return true;
 555                         }
 556                         return false; /* Not matched or bad pattern. */
 557                 }
 558                 filename++;
 559                 pattern++;
 560         }
 561         while (*pattern == '\\' &&
 562                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 563                 pattern += 2;
 564         return filename == filename_end && pattern == pattern_end;
 565 }
 566
 567 /**
 568  * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
 569  *
 570  * @filename:     The start of string to check.
 571  * @filename_end: The end of string to check.
 572  * @pattern:      The start of pattern to compare.
 573  * @pattern_end:  The end of pattern to compare.
 574  *
 575  * Returns true if @filename matches @pattern, false otherwise.
 576  */
 577 static bool tomoyo_file_matches_pattern(const char *filename,
 578                                            const char *filename_end,
 579                                            const char *pattern,
 580                                            const char *pattern_end)
 581 {
 582         const char *pattern_start = pattern;
 583         bool first = true;
 584         bool result;
 585
 586         while (pattern < pattern_end - 1) {
 587                 /* Split at "\-" pattern. */
 588                 if (*pattern++ != '\\' || *pattern++ != '-')
 589                         continue;
 590                 result = tomoyo_file_matches_pattern2(filename,
 591                                                       filename_end,
 592                                                       pattern_start,
 593                                                       pattern - 2);
 594                 if (first)
 595                         result = !result;
 596                 if (result)
 597                         return false;
 598                 first = false;
 599                 pattern_start = pattern;
 600         }
 601         result = tomoyo_file_matches_pattern2(filename, filename_end,
 602                                               pattern_start, pattern_end);
 603         return first ? result : !result;
 604 }
 605
 606 /**
 607  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 608  *
 609  * @f: The start of string to check.
 610  * @p: The start of pattern to compare.
 611  *
 612  * Returns true if @f matches @p, false otherwise.
 613  */
 614 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 615 {
 616         const char *f_delimiter;
 617         const char *p_delimiter;
 618
 619         while (*f && *p) {
 620                 f_delimiter = strchr(f, '/');
 621                 if (!f_delimiter)
 622                         f_delimiter = f + strlen(f);
 623                 p_delimiter = strchr(p, '/');
 624                 if (!p_delimiter)
 625                         p_delimiter = p + strlen(p);
 626                 if (*p == '\\' && *(p + 1) == '{')
 627                         goto recursive;
 628                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 629                                                  p_delimiter))
 630                         return false;
 631                 f = f_delimiter;
 632                 if (*f)
 633                         f++;
 634                 p = p_delimiter;
 635                 if (*p)
 636                         p++;
 637         }
 638         /* Ignore trailing "\*" and "\@" in @pattern. */
 639         while (*p == '\\' &&
 640                (*(p + 1) == '*' || *(p + 1) == '@'))
 641                 p += 2;
 642         return !*f && !*p;
 643  recursive:
 644         /*
 645          * The "\{" pattern is permitted only after '/' character.
 646          * This guarantees that below "*(p - 1)" is safe.
 647          * Also, the "\}" pattern is permitted only before '/' character
 648          * so that "\{" + "\}" pair will not break the "\-" operator.
 649          */
 650         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 651             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 652                 return false; /* Bad pattern. */
 653         do {
 654                 /* Compare current component with pattern. */
 655                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 656                                                  p_delimiter - 2))
 657                         break;
 658                 /* Proceed to next component. */
 659                 f = f_delimiter;
 660                 if (!*f)
 661                         break;
 662                 f++;
 663                 /* Continue comparison. */
 664                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 665                         return true;
 666                 f_delimiter = strchr(f, '/');
 667         } while (f_delimiter);
 668         return false; /* Not matched. */
 669 }
 670
 671 /**
 672  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 673  *
 674  * @filename: The filename to check.
 675  * @pattern:  The pattern to compare.
 676  *
 677  * Returns true if matches, false otherwise.
 678  *
 679  * The following patterns are available.
 680  *   \\     \ itself.
 681  *   \ooo   Octal representation of a byte.
 682  *   \*     Zero or more repetitions of characters other than '/'.
 683  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 684  *   \?     1 byte character other than '/'.
 685  *   \$     One or more repetitions of decimal digits.
 686  *   \+     1 decimal digit.
 687  *   \X     One or more repetitions of hexadecimal digits.
 688  *   \x     1 hexadecimal digit.
 689  *   \A     One or more repetitions of alphabet characters.
 690  *   \a     1 alphabet character.
 691  *
 692  *   \-     Subtraction operator.
 693  *
 694  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 695  *               /dir/dir/dir/ ).
 696  */
 697 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 698                                  const struct tomoyo_path_info *pattern)
 699 {
 700         const char *f = filename->name;
 701         const char *p = pattern->name;
 702         const int len = pattern->const_len;
 703
 704         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 705         if (!pattern->is_patterned)
 706                 return !tomoyo_pathcmp(filename, pattern);
 707         /* Don't compare directory and non-directory. */
 708         if (filename->is_dir != pattern->is_dir)
 709                 return false;
 710         /* Compare the initial length without patterns. */
 711         if (strncmp(f, p, len))
 712                 return false;
 713         f += len;
 714         p += len;
 715         return tomoyo_path_matches_pattern2(f, p);
 716 }
 717
 718 /**
 719  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 720  *
 721  * @head: Pointer to "struct tomoyo_io_buffer".
 722  * @fmt:  The printf()'s format string, followed by parameters.
 723  *
 724  * Returns true if output was written, false otherwise.
 725  *
 726  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 727  */
 728 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 729 {
 730         va_list args;
 731         int len;
 732         int pos = head->read_avail;
 733         int size = head->readbuf_size - pos;
 734
 735         if (size <= 0)
 736                 return false;
 737         va_start(args, fmt);
 738         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 739         va_end(args);
 740         if (pos + len >= head->readbuf_size)
 741                 return false;
 742         head->read_avail += len;
 743         return true;
 744 }
 745
 746 /**
 747  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 748  *
 749  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 750  *
 751  * This function uses kzalloc(), so the caller must call kfree()
 752  * if this function didn't return NULL.
 753  */
 754 static const char *tomoyo_get_exe(void)
 755 {
 756         struct mm_struct *mm = current->mm;
 757         struct vm_area_struct *vma;
 758         const char *cp = NULL;
 759
 760         if (!mm)
 761                 return NULL;
 762         down_read(&mm->mmap_sem);
 763         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 764                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 765                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 766                         break;
 767                 }
 768         }
 769         up_read(&mm->mmap_sem);
 770         return cp;
 771 }
 772
 773 /**
 774  * tomoyo_get_msg - Get warning message.
 775  *
 776  * @is_enforce: Is it enforcing mode?
 777  *
 778  * Returns "ERROR" or "WARNING".
 779  */
 780 const char *tomoyo_get_msg(const bool is_enforce)
 781 {
 782         if (is_enforce)
 783                 return "ERROR";
 784         else
 785                 return "WARNING";
 786 }
 787
 788 /**
 789  * tomoyo_check_flags - Check mode for specified functionality.
 790  *
 791  * @domain: Pointer to "struct tomoyo_domain_info".
 792  * @index:  The functionality to check mode.
 793  *
 794  * TOMOYO checks only process context.
 795  * This code disables TOMOYO's enforcement in case the function is called from
 796  * interrupt context.
 797  */
 798 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 799                                 const u8 index)
 800 {
 801         const u8 profile = domain->profile;
 802
 803         if (WARN_ON(in_interrupt()))
 804                 return 0;
 805         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 806 #if TOMOYO_MAX_PROFILES != 256
 807                 && profile < TOMOYO_MAX_PROFILES
 808 #endif
 809                 && tomoyo_profile_ptr[profile] ?
 810                 tomoyo_profile_ptr[profile]->value[index] : 0;
 811 }
 812
 813 /**
 814  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 815  *
 816  * @domain: Pointer to "struct tomoyo_domain_info".
 817  *
 818  * Returns true if domain policy violation warning should be printed to
 819  * console.
 820  */
 821 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 822 {
 823         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 824 }
 825
 826 /**
 827  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 828  *
 829  * @domain: Pointer to "struct tomoyo_domain_info".
 830  *
 831  * Returns true if the domain is not exceeded quota, false otherwise.
 832  *
 833  * Caller holds tomoyo_read_lock().
 834  */
 835 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 836 {
 837         unsigned int count = 0;
 838         struct tomoyo_acl_info *ptr;
 839
 840         if (!domain)
 841                 return true;
 842         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 843                 switch (ptr->type) {
 844                         struct tomoyo_single_path_acl_record *acl;
 845                         u32 perm;
 846                         u8 i;
 847                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
 848                         acl = container_of(ptr,
 849                                            struct tomoyo_single_path_acl_record,
 850                                            head);
 851                         perm = acl->perm | (((u32) acl->perm_high) << 16);
 852                         for (i = 0; i < TOMOYO_MAX_SINGLE_PATH_OPERATION; i++)
 853                                 if (perm & (1 << i))
 854                                         count++;
 855                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL))
 856                                 count -= 2;
 857                         break;
 858                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
 859                         perm = container_of(ptr,
 860                                     struct tomoyo_double_path_acl_record,
 861                                             head)->perm;
 862                         for (i = 0; i < TOMOYO_MAX_DOUBLE_PATH_OPERATION; i++)
 863                                 if (perm & (1 << i))
 864                                         count++;
 865                         break;
 866                 }
 867         }
 868         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 869                 return true;
 870         if (!domain->quota_warned) {
 871                 domain->quota_warned = true;
 872                 printk(KERN_WARNING "TOMOYO-WARNING: "
 873                        "Domain '%s' has so many ACLs to hold. "
 874                        "Stopped learning mode.\n", domain->domainname->name);
 875         }
 876         return false;
 877 }
 878
 879 /**
 880  * tomoyo_find_or_assign_new_profile - Create a new profile.
 881  *
 882  * @profile: Profile number to create.
 883  *
 884  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 885  */
 886 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 887                                                                 int profile)
 888 {
 889         static DEFINE_MUTEX(lock);
 890         struct tomoyo_profile *ptr = NULL;
 891         int i;
 892
 893         if (profile >= TOMOYO_MAX_PROFILES)
 894                 return NULL;
 895         mutex_lock(&lock);
 896         ptr = tomoyo_profile_ptr[profile];
 897         if (ptr)
 898                 goto ok;
 899         ptr = kmalloc(sizeof(*ptr), GFP_KERNEL);
 900         if (!tomoyo_memory_ok(ptr)) {
 901                 kfree(ptr);
 902                 goto ok;
 903         }
 904         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 905                 ptr->value[i] = tomoyo_control_array[i].current_value;
 906         mb(); /* Avoid out-of-order execution. */
 907         tomoyo_profile_ptr[profile] = ptr;
 908  ok:
 909         mutex_unlock(&lock);
 910         return ptr;
 911 }
 912
 913 /**
 914  * tomoyo_write_profile - Write to profile table.
 915  *
 916  * @head: Pointer to "struct tomoyo_io_buffer".
 917  *
 918  * Returns 0 on success, negative value otherwise.
 919  */
 920 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 921 {
 922         char *data = head->write_buf;
 923         unsigned int i;
 924         unsigned int value;
 925         char *cp;
 926         struct tomoyo_profile *profile;
 927         unsigned long num;
 928
 929         cp = strchr(data, '-');
 930         if (cp)
 931                 *cp = '\0';
 932         if (strict_strtoul(data, 10, &num))
 933                 return -EINVAL;
 934         if (cp)
 935                 data = cp + 1;
 936         profile = tomoyo_find_or_assign_new_profile(num);
 937         if (!profile)
 938                 return -EINVAL;
 939         cp = strchr(data, '=');
 940         if (!cp)
 941                 return -EINVAL;
 942         *cp = '\0';
 943         if (!strcmp(data, "COMMENT")) {
 944                 const struct tomoyo_path_info *old_comment = profile->comment;
 945                 profile->comment = tomoyo_get_name(cp + 1);
 946                 tomoyo_put_name(old_comment);
 947                 return 0;
 948         }
 949         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 950                 if (strcmp(data, tomoyo_control_array[i].keyword))
 951                         continue;
 952                 if (sscanf(cp + 1, "%u", &value) != 1) {
 953                         int j;
 954                         const char **modes;
 955                         switch (i) {
 956                         case TOMOYO_VERBOSE:
 957                                 modes = tomoyo_mode_2;
 958                                 break;
 959                         default:
 960                                 modes = tomoyo_mode_4;
 961                                 break;
 962                         }
 963                         for (j = 0; j < 4; j++) {
 964                                 if (strcmp(cp + 1, modes[j]))
 965                                         continue;
 966                                 value = j;
 967                                 break;
 968                         }
 969                         if (j == 4)
 970                                 return -EINVAL;
 971                 } else if (value > tomoyo_control_array[i].max_value) {
 972                         value = tomoyo_control_array[i].max_value;
 973                 }
 974                 profile->value[i] = value;
 975                 return 0;
 976         }
 977         return -EINVAL;
 978 }
 979
 980 /**
 981  * tomoyo_read_profile - Read from profile table.
 982  *
 983  * @head: Pointer to "struct tomoyo_io_buffer".
 984  *
 985  * Returns 0.
 986  */
 987 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 988 {
 989         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 990         int step;
 991
 992         if (head->read_eof)
 993                 return 0;
 994         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 995              step++) {
 996                 const u8 index = step / total;
 997                 u8 type = step % total;
 998                 const struct tomoyo_profile *profile
 999                         = tomoyo_profile_ptr[index];
1000                 head->read_step = step;
1001                 if (!profile)
1002                         continue;
1003                 if (!type) { /* Print profile' comment tag. */
1004                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
1005                                               index, profile->comment ?
1006                                               profile->comment->name : ""))
1007                                 break;
1008                         continue;
1009                 }
1010                 type--;
1011                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1012                         const unsigned int value = profile->value[type];
1013                         const char **modes = NULL;
1014                         const char *keyword
1015                                 = tomoyo_control_array[type].keyword;
1016                         switch (tomoyo_control_array[type].max_value) {
1017                         case 3:
1018                                 modes = tomoyo_mode_4;
1019                                 break;
1020                         case 1:
1021                                 modes = tomoyo_mode_2;
1022                                 break;
1023                         }
1024                         if (modes) {
1025                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1026                                                       keyword, modes[value]))
1027                                         break;
1028                         } else {
1029                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1030                                                       keyword, value))
1031                                         break;
1032                         }
1033                 }
1034         }
1035         if (step == TOMOYO_MAX_PROFILES * total)
1036                 head->read_eof = true;
1037         return 0;
1038 }
1039
1040 /*
1041  * tomoyo_policy_manager_list is used for holding list of domainnames or
1042  * programs which are permitted to modify configuration via
1043  * /sys/kernel/security/tomoyo/ interface.
1044  *
1045  * An entry is added by
1046  *
1047  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1048  *                                        /sys/kernel/security/tomoyo/manager
1049  *  (if you want to specify by a domainname)
1050  *
1051  *  or
1052  *
1053  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1054  *  (if you want to specify by a program's location)
1055  *
1056  * and is deleted by
1057  *
1058  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1059  *                                        /sys/kernel/security/tomoyo/manager
1060  *
1061  *  or
1062  *
1063  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1064  *                                        /sys/kernel/security/tomoyo/manager
1065  *
1066  * and all entries are retrieved by
1067  *
1068  * # cat /sys/kernel/security/tomoyo/manager
1069  */
1070 LIST_HEAD(tomoyo_policy_manager_list);
1071
1072 /**
1073  * tomoyo_update_manager_entry - Add a manager entry.
1074  *
1075  * @manager:   The path to manager or the domainnamme.
1076  * @is_delete: True if it is a delete request.
1077  *
1078  * Returns 0 on success, negative value otherwise.
1079  *
1080  * Caller holds tomoyo_read_lock().
1081  */
1082 static int tomoyo_update_manager_entry(const char *manager,
1083                                        const bool is_delete)
1084 {
1085         struct tomoyo_policy_manager_entry *entry = NULL;
1086         struct tomoyo_policy_manager_entry *ptr;
1087         const struct tomoyo_path_info *saved_manager;
1088         int error = is_delete ? -ENOENT : -ENOMEM;
1089         bool is_domain = false;
1090
1091         if (tomoyo_is_domain_def(manager)) {
1092                 if (!tomoyo_is_correct_domain(manager, __func__))
1093                         return -EINVAL;
1094                 is_domain = true;
1095         } else {
1096                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1097                         return -EINVAL;
1098         }
1099         saved_manager = tomoyo_get_name(manager);
1100         if (!saved_manager)
1101                 return -ENOMEM;
1102         if (!is_delete)
1103                 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1104         mutex_lock(&tomoyo_policy_lock);
1105         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1106                 if (ptr->manager != saved_manager)
1107                         continue;
1108                 ptr->is_deleted = is_delete;
1109                 error = 0;
1110                 break;
1111         }
1112         if (!is_delete && error && tomoyo_memory_ok(entry)) {
1113                 entry->manager = saved_manager;
1114                 saved_manager = NULL;
1115                 entry->is_domain = is_domain;
1116                 list_add_tail_rcu(&entry->list, &tomoyo_policy_manager_list);
1117                 entry = NULL;
1118                 error = 0;
1119         }
1120         mutex_unlock(&tomoyo_policy_lock);
1121         tomoyo_put_name(saved_manager);
1122         kfree(entry);
1123         return error;
1124 }
1125
1126 /**
1127  * tomoyo_write_manager_policy - Write manager policy.
1128  *
1129  * @head: Pointer to "struct tomoyo_io_buffer".
1130  *
1131  * Returns 0 on success, negative value otherwise.
1132  *
1133  * Caller holds tomoyo_read_lock().
1134  */
1135 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1136 {
1137         char *data = head->write_buf;
1138         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1139
1140         if (!strcmp(data, "manage_by_non_root")) {
1141                 tomoyo_manage_by_non_root = !is_delete;
1142                 return 0;
1143         }
1144         return tomoyo_update_manager_entry(data, is_delete);
1145 }
1146
1147 /**
1148  * tomoyo_read_manager_policy - Read manager policy.
1149  *
1150  * @head: Pointer to "struct tomoyo_io_buffer".
1151  *
1152  * Returns 0.
1153  *
1154  * Caller holds tomoyo_read_lock().
1155  */
1156 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1157 {
1158         struct list_head *pos;
1159         bool done = true;
1160
1161         if (head->read_eof)
1162                 return 0;
1163         list_for_each_cookie(pos, head->read_var2,
1164                              &tomoyo_policy_manager_list) {
1165                 struct tomoyo_policy_manager_entry *ptr;
1166                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1167                                  list);
1168                 if (ptr->is_deleted)
1169                         continue;
1170                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1171                 if (!done)
1172                         break;
1173         }
1174         head->read_eof = done;
1175         return 0;
1176 }
1177
1178 /**
1179  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1180  *
1181  * Returns true if the current process is permitted to modify policy
1182  * via /sys/kernel/security/tomoyo/ interface.
1183  *
1184  * Caller holds tomoyo_read_lock().
1185  */
1186 static bool tomoyo_is_policy_manager(void)
1187 {
1188         struct tomoyo_policy_manager_entry *ptr;
1189         const char *exe;
1190         const struct task_struct *task = current;
1191         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1192         bool found = false;
1193
1194         if (!tomoyo_policy_loaded)
1195                 return true;
1196         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1197                 return false;
1198         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1199                 if (!ptr->is_deleted && ptr->is_domain
1200                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1201                         found = true;
1202                         break;
1203                 }
1204         }
1205         if (found)
1206                 return true;
1207         exe = tomoyo_get_exe();
1208         if (!exe)
1209                 return false;
1210         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1211                 if (!ptr->is_deleted && !ptr->is_domain
1212                     && !strcmp(exe, ptr->manager->name)) {
1213                         found = true;
1214                         break;
1215                 }
1216         }
1217         if (!found) { /* Reduce error messages. */
1218                 static pid_t last_pid;
1219                 const pid_t pid = current->pid;
1220                 if (last_pid != pid) {
1221                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1222                                "update policies.\n", domainname->name, exe);
1223                         last_pid = pid;
1224                 }
1225         }
1226         kfree(exe);
1227         return found;
1228 }
1229
1230 /**
1231  * tomoyo_is_select_one - Parse select command.
1232  *
1233  * @head: Pointer to "struct tomoyo_io_buffer".
1234  * @data: String to parse.
1235  *
1236  * Returns true on success, false otherwise.
1237  *
1238  * Caller holds tomoyo_read_lock().
1239  */
1240 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1241                                  const char *data)
1242 {
1243         unsigned int pid;
1244         struct tomoyo_domain_info *domain = NULL;
1245
1246         if (sscanf(data, "pid=%u", &pid) == 1) {
1247                 struct task_struct *p;
1248                 read_lock(&tasklist_lock);
1249                 p = find_task_by_vpid(pid);
1250                 if (p)
1251                         domain = tomoyo_real_domain(p);
1252                 read_unlock(&tasklist_lock);
1253         } else if (!strncmp(data, "domain=", 7)) {
1254                 if (tomoyo_is_domain_def(data + 7))
1255                         domain = tomoyo_find_domain(data + 7);
1256         } else
1257                 return false;
1258         head->write_var1 = domain;
1259         /* Accessing read_buf is safe because head->io_sem is held. */
1260         if (!head->read_buf)
1261                 return true; /* Do nothing if open(O_WRONLY). */
1262         head->read_avail = 0;
1263         tomoyo_io_printf(head, "# select %s\n", data);
1264         head->read_single_domain = true;
1265         head->read_eof = !domain;
1266         if (domain) {
1267                 struct tomoyo_domain_info *d;
1268                 head->read_var1 = NULL;
1269                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1270                         if (d == domain)
1271                                 break;
1272                         head->read_var1 = &d->list;
1273                 }
1274                 head->read_var2 = NULL;
1275                 head->read_bit = 0;
1276                 head->read_step = 0;
1277                 if (domain->is_deleted)
1278                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1279         }
1280         return true;
1281 }
1282
1283 /**
1284  * tomoyo_delete_domain - Delete a domain.
1285  *
1286  * @domainname: The name of domain.
1287  *
1288  * Returns 0.
1289  *
1290  * Caller holds tomoyo_read_lock().
1291  */
1292 static int tomoyo_delete_domain(char *domainname)
1293 {
1294         struct tomoyo_domain_info *domain;
1295         struct tomoyo_path_info name;
1296
1297         name.name = domainname;
1298         tomoyo_fill_path_info(&name);
1299         mutex_lock(&tomoyo_policy_lock);
1300         /* Is there an active domain? */
1301         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1302                 /* Never delete tomoyo_kernel_domain */
1303                 if (domain == &tomoyo_kernel_domain)
1304                         continue;
1305                 if (domain->is_deleted ||
1306                     tomoyo_pathcmp(domain->domainname, &name))
1307                         continue;
1308                 domain->is_deleted = true;
1309                 break;
1310         }
1311         mutex_unlock(&tomoyo_policy_lock);
1312         return 0;
1313 }
1314
1315 /**
1316  * tomoyo_write_domain_policy - Write domain policy.
1317  *
1318  * @head: Pointer to "struct tomoyo_io_buffer".
1319  *
1320  * Returns 0 on success, negative value otherwise.
1321  *
1322  * Caller holds tomoyo_read_lock().
1323  */
1324 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1325 {
1326         char *data = head->write_buf;
1327         struct tomoyo_domain_info *domain = head->write_var1;
1328         bool is_delete = false;
1329         bool is_select = false;
1330         unsigned int profile;
1331
1332         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1333                 is_delete = true;
1334         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1335                 is_select = true;
1336         if (is_select && tomoyo_is_select_one(head, data))
1337                 return 0;
1338         /* Don't allow updating policies by non manager programs. */
1339         if (!tomoyo_is_policy_manager())
1340                 return -EPERM;
1341         if (tomoyo_is_domain_def(data)) {
1342                 domain = NULL;
1343                 if (is_delete)
1344                         tomoyo_delete_domain(data);
1345                 else if (is_select)
1346                         domain = tomoyo_find_domain(data);
1347                 else
1348                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1349                 head->write_var1 = domain;
1350                 return 0;
1351         }
1352         if (!domain)
1353                 return -EINVAL;
1354
1355         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1356             && profile < TOMOYO_MAX_PROFILES) {
1357                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1358                         domain->profile = (u8) profile;
1359                 return 0;
1360         }
1361         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1362                 domain->ignore_global_allow_read = !is_delete;
1363                 return 0;
1364         }
1365         return tomoyo_write_file_policy(data, domain, is_delete);
1366 }
1367
1368 /**
1369  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1370  *
1371  * @head: Pointer to "struct tomoyo_io_buffer".
1372  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1373  *
1374  * Returns true on success, false otherwise.
1375  */
1376 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1377                                          struct tomoyo_single_path_acl_record *
1378                                          ptr)
1379 {
1380         int pos;
1381         u8 bit;
1382         const char *atmark = "";
1383         const char *filename;
1384         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1385
1386         filename = ptr->filename->name;
1387         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1388              bit++) {
1389                 const char *msg;
1390                 if (!(perm & (1 << bit)))
1391                         continue;
1392                 /* Print "read/write" instead of "read" and "write". */
1393                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1394                      bit == TOMOYO_TYPE_WRITE_ACL)
1395                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1396                         continue;
1397                 msg = tomoyo_sp2keyword(bit);
1398                 pos = head->read_avail;
1399                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1400                                       atmark, filename))
1401                         goto out;
1402         }
1403         head->read_bit = 0;
1404         return true;
1405  out:
1406         head->read_bit = bit;
1407         head->read_avail = pos;
1408         return false;
1409 }
1410
1411 /**
1412  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1413  *
1414  * @head: Pointer to "struct tomoyo_io_buffer".
1415  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1416  *
1417  * Returns true on success, false otherwise.
1418  */
1419 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1420                                          struct tomoyo_double_path_acl_record *
1421                                          ptr)
1422 {
1423         int pos;
1424         const char *atmark1 = "";
1425         const char *atmark2 = "";
1426         const char *filename1;
1427         const char *filename2;
1428         const u8 perm = ptr->perm;
1429         u8 bit;
1430
1431         filename1 = ptr->filename1->name;
1432         filename2 = ptr->filename2->name;
1433         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1434              bit++) {
1435                 const char *msg;
1436                 if (!(perm & (1 << bit)))
1437                         continue;
1438                 msg = tomoyo_dp2keyword(bit);
1439                 pos = head->read_avail;
1440                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1441                                       atmark1, filename1, atmark2, filename2))
1442                         goto out;
1443         }
1444         head->read_bit = 0;
1445         return true;
1446  out:
1447         head->read_bit = bit;
1448         head->read_avail = pos;
1449         return false;
1450 }
1451
1452 /**
1453  * tomoyo_print_entry - Print an ACL entry.
1454  *
1455  * @head: Pointer to "struct tomoyo_io_buffer".
1456  * @ptr:  Pointer to an ACL entry.
1457  *
1458  * Returns true on success, false otherwise.
1459  */
1460 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1461                                struct tomoyo_acl_info *ptr)
1462 {
1463         const u8 acl_type = ptr->type;
1464
1465         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1466                 struct tomoyo_single_path_acl_record *acl
1467                         = container_of(ptr,
1468                                        struct tomoyo_single_path_acl_record,
1469                                        head);
1470                 return tomoyo_print_single_path_acl(head, acl);
1471         }
1472         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1473                 struct tomoyo_double_path_acl_record *acl
1474                         = container_of(ptr,
1475                                        struct tomoyo_double_path_acl_record,
1476                                        head);
1477                 return tomoyo_print_double_path_acl(head, acl);
1478         }
1479         BUG(); /* This must not happen. */
1480         return false;
1481 }
1482
1483 /**
1484  * tomoyo_read_domain_policy - Read domain policy.
1485  *
1486  * @head: Pointer to "struct tomoyo_io_buffer".
1487  *
1488  * Returns 0.
1489  *
1490  * Caller holds tomoyo_read_lock().
1491  */
1492 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1493 {
1494         struct list_head *dpos;
1495         struct list_head *apos;
1496         bool done = true;
1497
1498         if (head->read_eof)
1499                 return 0;
1500         if (head->read_step == 0)
1501                 head->read_step = 1;
1502         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1503                 struct tomoyo_domain_info *domain;
1504                 const char *quota_exceeded = "";
1505                 const char *transition_failed = "";
1506                 const char *ignore_global_allow_read = "";
1507                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1508                 if (head->read_step != 1)
1509                         goto acl_loop;
1510                 if (domain->is_deleted && !head->read_single_domain)
1511                         continue;
1512                 /* Print domainname and flags. */
1513                 if (domain->quota_warned)
1514                         quota_exceeded = "quota_exceeded\n";
1515                 if (domain->transition_failed)
1516                         transition_failed = "transition_failed\n";
1517                 if (domain->ignore_global_allow_read)
1518                         ignore_global_allow_read
1519                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1520                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1521                                         "%u\n%s%s%s\n",
1522                                         domain->domainname->name,
1523                                         domain->profile, quota_exceeded,
1524                                         transition_failed,
1525                                         ignore_global_allow_read);
1526                 if (!done)
1527                         break;
1528                 head->read_step = 2;
1529 acl_loop:
1530                 if (head->read_step == 3)
1531                         goto tail_mark;
1532                 /* Print ACL entries in the domain. */
1533                 list_for_each_cookie(apos, head->read_var2,
1534                                      &domain->acl_info_list) {
1535                         struct tomoyo_acl_info *ptr
1536                                 = list_entry(apos, struct tomoyo_acl_info,
1537                                              list);
1538                         done = tomoyo_print_entry(head, ptr);
1539                         if (!done)
1540                                 break;
1541                 }
1542                 if (!done)
1543                         break;
1544                 head->read_step = 3;
1545 tail_mark:
1546                 done = tomoyo_io_printf(head, "\n");
1547                 if (!done)
1548                         break;
1549                 head->read_step = 1;
1550                 if (head->read_single_domain)
1551                         break;
1552         }
1553         head->read_eof = done;
1554         return 0;
1555 }
1556
1557 /**
1558  * tomoyo_write_domain_profile - Assign profile for specified domain.
1559  *
1560  * @head: Pointer to "struct tomoyo_io_buffer".
1561  *
1562  * Returns 0 on success, -EINVAL otherwise.
1563  *
1564  * This is equivalent to doing
1565  *
1566  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1567  *     /usr/lib/ccs/loadpolicy -d
1568  *
1569  * Caller holds tomoyo_read_lock().
1570  */
1571 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1572 {
1573         char *data = head->write_buf;
1574         char *cp = strchr(data, ' ');
1575         struct tomoyo_domain_info *domain;
1576         unsigned long profile;
1577
1578         if (!cp)
1579                 return -EINVAL;
1580         *cp = '\0';
1581         domain = tomoyo_find_domain(cp + 1);
1582         if (strict_strtoul(data, 10, &profile))
1583                 return -EINVAL;
1584         if (domain && profile < TOMOYO_MAX_PROFILES
1585             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1586                 domain->profile = (u8) profile;
1587         return 0;
1588 }
1589
1590 /**
1591  * tomoyo_read_domain_profile - Read only domainname and profile.
1592  *
1593  * @head: Pointer to "struct tomoyo_io_buffer".
1594  *
1595  * Returns list of profile number and domainname pairs.
1596  *
1597  * This is equivalent to doing
1598  *
1599  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1600  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1601  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1602  *     print $2 " " domainname; domainname = ""; } } ; '
1603  *
1604  * Caller holds tomoyo_read_lock().
1605  */
1606 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1607 {
1608         struct list_head *pos;
1609         bool done = true;
1610
1611         if (head->read_eof)
1612                 return 0;
1613         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1614                 struct tomoyo_domain_info *domain;
1615                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1616                 if (domain->is_deleted)
1617                         continue;
1618                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1619                                         domain->domainname->name);
1620                 if (!done)
1621                         break;
1622         }
1623         head->read_eof = done;
1624         return 0;
1625 }
1626
1627 /**
1628  * tomoyo_write_pid: Specify PID to obtain domainname.
1629  *
1630  * @head: Pointer to "struct tomoyo_io_buffer".
1631  *
1632  * Returns 0.
1633  */
1634 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1635 {
1636         unsigned long pid;
1637         /* No error check. */
1638         strict_strtoul(head->write_buf, 10, &pid);
1639         head->read_step = (int) pid;
1640         head->read_eof = false;
1641         return 0;
1642 }
1643
1644 /**
1645  * tomoyo_read_pid - Get domainname of the specified PID.
1646  *
1647  * @head: Pointer to "struct tomoyo_io_buffer".
1648  *
1649  * Returns the domainname which the specified PID is in on success,
1650  * empty string otherwise.
1651  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1652  * using read()/write() interface rather than sysctl() interface.
1653  */
1654 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1655 {
1656         if (head->read_avail == 0 && !head->read_eof) {
1657                 const int pid = head->read_step;
1658                 struct task_struct *p;
1659                 struct tomoyo_domain_info *domain = NULL;
1660                 read_lock(&tasklist_lock);
1661                 p = find_task_by_vpid(pid);
1662                 if (p)
1663                         domain = tomoyo_real_domain(p);
1664                 read_unlock(&tasklist_lock);
1665                 if (domain)
1666                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1667                                          domain->domainname->name);
1668                 head->read_eof = true;
1669         }
1670         return 0;
1671 }
1672
1673 /**
1674  * tomoyo_write_exception_policy - Write exception policy.
1675  *
1676  * @head: Pointer to "struct tomoyo_io_buffer".
1677  *
1678  * Returns 0 on success, negative value otherwise.
1679  *
1680  * Caller holds tomoyo_read_lock().
1681  */
1682 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1683 {
1684         char *data = head->write_buf;
1685         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1686
1687         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1688                 return tomoyo_write_domain_keeper_policy(data, false,
1689                                                          is_delete);
1690         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1691                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1692         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1693                 return tomoyo_write_domain_initializer_policy(data, false,
1694                                                               is_delete);
1695         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1696                 return tomoyo_write_domain_initializer_policy(data, true,
1697                                                               is_delete);
1698         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1699                 return tomoyo_write_alias_policy(data, is_delete);
1700         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1701                 return tomoyo_write_globally_readable_policy(data, is_delete);
1702         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1703                 return tomoyo_write_pattern_policy(data, is_delete);
1704         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1705                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1706         return -EINVAL;
1707 }
1708
1709 /**
1710  * tomoyo_read_exception_policy - Read exception policy.
1711  *
1712  * @head: Pointer to "struct tomoyo_io_buffer".
1713  *
1714  * Returns 0 on success, -EINVAL otherwise.
1715  *
1716  * Caller holds tomoyo_read_lock().
1717  */
1718 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1719 {
1720         if (!head->read_eof) {
1721                 switch (head->read_step) {
1722                 case 0:
1723                         head->read_var2 = NULL;
1724                         head->read_step = 1;
1725                 case 1:
1726                         if (!tomoyo_read_domain_keeper_policy(head))
1727                                 break;
1728                         head->read_var2 = NULL;
1729                         head->read_step = 2;
1730                 case 2:
1731                         if (!tomoyo_read_globally_readable_policy(head))
1732                                 break;
1733                         head->read_var2 = NULL;
1734                         head->read_step = 3;
1735                 case 3:
1736                         head->read_var2 = NULL;
1737                         head->read_step = 4;
1738                 case 4:
1739                         if (!tomoyo_read_domain_initializer_policy(head))
1740                                 break;
1741                         head->read_var2 = NULL;
1742                         head->read_step = 5;
1743                 case 5:
1744                         if (!tomoyo_read_alias_policy(head))
1745                                 break;
1746                         head->read_var2 = NULL;
1747                         head->read_step = 6;
1748                 case 6:
1749                         head->read_var2 = NULL;
1750                         head->read_step = 7;
1751                 case 7:
1752                         if (!tomoyo_read_file_pattern(head))
1753                                 break;
1754                         head->read_var2 = NULL;
1755                         head->read_step = 8;
1756                 case 8:
1757                         if (!tomoyo_read_no_rewrite_policy(head))
1758                                 break;
1759                         head->read_var2 = NULL;
1760                         head->read_step = 9;
1761                 case 9:
1762                         head->read_eof = true;
1763                         break;
1764                 default:
1765                         return -EINVAL;
1766                 }
1767         }
1768         return 0;
1769 }
1770
1771 /* path to policy loader */
1772 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1773
1774 /**
1775  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1776  *
1777  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1778  */
1779 static bool tomoyo_policy_loader_exists(void)
1780 {
1781         /*
1782          * Don't activate MAC if the policy loader doesn't exist.
1783          * If the initrd includes /sbin/init but real-root-dev has not
1784          * mounted on / yet, activating MAC will block the system since
1785          * policies are not loaded yet.
1786          * Thus, let do_execve() call this function everytime.
1787          */
1788         struct path path;
1789
1790         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1791                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1792                        "since %s doesn't exist.\n", tomoyo_loader);
1793                 return false;
1794         }
1795         path_put(&path);
1796         return true;
1797 }
1798
1799 /**
1800  * tomoyo_load_policy - Run external policy loader to load policy.
1801  *
1802  * @filename: The program about to start.
1803  *
1804  * This function checks whether @filename is /sbin/init , and if so
1805  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1806  * and then continues invocation of /sbin/init.
1807  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1808  * writes to /sys/kernel/security/tomoyo/ interfaces.
1809  *
1810  * Returns nothing.
1811  */
1812 void tomoyo_load_policy(const char *filename)
1813 {
1814         char *argv[2];
1815         char *envp[3];
1816
1817         if (tomoyo_policy_loaded)
1818                 return;
1819         /*
1820          * Check filename is /sbin/init or /sbin/tomoyo-start.
1821          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1822          * be passed.
1823          * You can create /sbin/tomoyo-start by
1824          * "ln -s /bin/true /sbin/tomoyo-start".
1825          */
1826         if (strcmp(filename, "/sbin/init") &&
1827             strcmp(filename, "/sbin/tomoyo-start"))
1828                 return;
1829         if (!tomoyo_policy_loader_exists())
1830                 return;
1831
1832         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1833                tomoyo_loader);
1834         argv[0] = (char *) tomoyo_loader;
1835         argv[1] = NULL;
1836         envp[0] = "HOME=/";
1837         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1838         envp[2] = NULL;
1839         call_usermodehelper(argv[0], argv, envp, 1);
1840
1841         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1842         printk(KERN_INFO "Mandatory Access Control activated.\n");
1843         tomoyo_policy_loaded = true;
1844         { /* Check all profiles currently assigned to domains are defined. */
1845                 struct tomoyo_domain_info *domain;
1846                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1847                         const u8 profile = domain->profile;
1848                         if (tomoyo_profile_ptr[profile])
1849                                 continue;
1850                         panic("Profile %u (used by '%s') not defined.\n",
1851                               profile, domain->domainname->name);
1852                 }
1853         }
1854 }
1855
1856 /**
1857  * tomoyo_read_version: Get version.
1858  *
1859  * @head: Pointer to "struct tomoyo_io_buffer".
1860  *
1861  * Returns version information.
1862  */
1863 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1864 {
1865         if (!head->read_eof) {
1866                 tomoyo_io_printf(head, "2.2.0");
1867                 head->read_eof = true;
1868         }
1869         return 0;
1870 }
1871
1872 /**
1873  * tomoyo_read_self_domain - Get the current process's domainname.
1874  *
1875  * @head: Pointer to "struct tomoyo_io_buffer".
1876  *
1877  * Returns the current process's domainname.
1878  */
1879 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1880 {
1881         if (!head->read_eof) {
1882                 /*
1883                  * tomoyo_domain()->domainname != NULL
1884                  * because every process belongs to a domain and
1885                  * the domain's name cannot be NULL.
1886                  */
1887                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1888                 head->read_eof = true;
1889         }
1890         return 0;
1891 }
1892
1893 /**
1894  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1895  *
1896  * @type: Type of interface.
1897  * @file: Pointer to "struct file".
1898  *
1899  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1900  *
1901  * Caller acquires tomoyo_read_lock().
1902  */
1903 static int tomoyo_open_control(const u8 type, struct file *file)
1904 {
1905         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_KERNEL);
1906
1907         if (!head)
1908                 return -ENOMEM;
1909         mutex_init(&head->io_sem);
1910         switch (type) {
1911         case TOMOYO_DOMAINPOLICY:
1912                 /* /sys/kernel/security/tomoyo/domain_policy */
1913                 head->write = tomoyo_write_domain_policy;
1914                 head->read = tomoyo_read_domain_policy;
1915                 break;
1916         case TOMOYO_EXCEPTIONPOLICY:
1917                 /* /sys/kernel/security/tomoyo/exception_policy */
1918                 head->write = tomoyo_write_exception_policy;
1919                 head->read = tomoyo_read_exception_policy;
1920                 break;
1921         case TOMOYO_SELFDOMAIN:
1922                 /* /sys/kernel/security/tomoyo/self_domain */
1923                 head->read = tomoyo_read_self_domain;
1924                 break;
1925         case TOMOYO_DOMAIN_STATUS:
1926                 /* /sys/kernel/security/tomoyo/.domain_status */
1927                 head->write = tomoyo_write_domain_profile;
1928                 head->read = tomoyo_read_domain_profile;
1929                 break;
1930         case TOMOYO_PROCESS_STATUS:
1931                 /* /sys/kernel/security/tomoyo/.process_status */
1932                 head->write = tomoyo_write_pid;
1933                 head->read = tomoyo_read_pid;
1934                 break;
1935         case TOMOYO_VERSION:
1936                 /* /sys/kernel/security/tomoyo/version */
1937                 head->read = tomoyo_read_version;
1938                 head->readbuf_size = 128;
1939                 break;
1940         case TOMOYO_MEMINFO:
1941                 /* /sys/kernel/security/tomoyo/meminfo */
1942                 head->write = tomoyo_write_memory_quota;
1943                 head->read = tomoyo_read_memory_counter;
1944                 head->readbuf_size = 512;
1945                 break;
1946         case TOMOYO_PROFILE:
1947                 /* /sys/kernel/security/tomoyo/profile */
1948                 head->write = tomoyo_write_profile;
1949                 head->read = tomoyo_read_profile;
1950                 break;
1951         case TOMOYO_MANAGER:
1952                 /* /sys/kernel/security/tomoyo/manager */
1953                 head->write = tomoyo_write_manager_policy;
1954                 head->read = tomoyo_read_manager_policy;
1955                 break;
1956         }
1957         if (!(file->f_mode & FMODE_READ)) {
1958                 /*
1959                  * No need to allocate read_buf since it is not opened
1960                  * for reading.
1961                  */
1962                 head->read = NULL;
1963         } else {
1964                 if (!head->readbuf_size)
1965                         head->readbuf_size = 4096 * 2;
1966                 head->read_buf = kzalloc(head->readbuf_size, GFP_KERNEL);
1967                 if (!head->read_buf) {
1968                         kfree(head);
1969                         return -ENOMEM;
1970                 }
1971         }
1972         if (!(file->f_mode & FMODE_WRITE)) {
1973                 /*
1974                  * No need to allocate write_buf since it is not opened
1975                  * for writing.
1976                  */
1977                 head->write = NULL;
1978         } else if (head->write) {
1979                 head->writebuf_size = 4096 * 2;
1980                 head->write_buf = kzalloc(head->writebuf_size, GFP_KERNEL);
1981                 if (!head->write_buf) {
1982                         kfree(head->read_buf);
1983                         kfree(head);
1984                         return -ENOMEM;
1985                 }
1986         }
1987         head->reader_idx = tomoyo_read_lock();
1988         file->private_data = head;
1989         /*
1990          * Call the handler now if the file is
1991          * /sys/kernel/security/tomoyo/self_domain
1992          * so that the user can use
1993          * cat < /sys/kernel/security/tomoyo/self_domain"
1994          * to know the current process's domainname.
1995          */
1996         if (type == TOMOYO_SELFDOMAIN)
1997                 tomoyo_read_control(file, NULL, 0);
1998         return 0;
1999 }
2000
2001 /**
2002  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
2003  *
2004  * @file:       Pointer to "struct file".
2005  * @buffer:     Poiner to buffer to write to.
2006  * @buffer_len: Size of @buffer.
2007  *
2008  * Returns bytes read on success, negative value otherwise.
2009  *
2010  * Caller holds tomoyo_read_lock().
2011  */
2012 static int tomoyo_read_control(struct file *file, char __user *buffer,
2013                                const int buffer_len)
2014 {
2015         int len = 0;
2016         struct tomoyo_io_buffer *head = file->private_data;
2017         char *cp;
2018
2019         if (!head->read)
2020                 return -ENOSYS;
2021         if (mutex_lock_interruptible(&head->io_sem))
2022                 return -EINTR;
2023         /* Call the policy handler. */
2024         len = head->read(head);
2025         if (len < 0)
2026                 goto out;
2027         /* Write to buffer. */
2028         len = head->read_avail;
2029         if (len > buffer_len)
2030                 len = buffer_len;
2031         if (!len)
2032                 goto out;
2033         /* head->read_buf changes by some functions. */
2034         cp = head->read_buf;
2035         if (copy_to_user(buffer, cp, len)) {
2036                 len = -EFAULT;
2037                 goto out;
2038         }
2039         head->read_avail -= len;
2040         memmove(cp, cp + len, head->read_avail);
2041  out:
2042         mutex_unlock(&head->io_sem);
2043         return len;
2044 }
2045
2046 /**
2047  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2048  *
2049  * @file:       Pointer to "struct file".
2050  * @buffer:     Pointer to buffer to read from.
2051  * @buffer_len: Size of @buffer.
2052  *
2053  * Returns @buffer_len on success, negative value otherwise.
2054  *
2055  * Caller holds tomoyo_read_lock().
2056  */
2057 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2058                                 const int buffer_len)
2059 {
2060         struct tomoyo_io_buffer *head = file->private_data;
2061         int error = buffer_len;
2062         int avail_len = buffer_len;
2063         char *cp0 = head->write_buf;
2064
2065         if (!head->write)
2066                 return -ENOSYS;
2067         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2068                 return -EFAULT;
2069         /* Don't allow updating policies by non manager programs. */
2070         if (head->write != tomoyo_write_pid &&
2071             head->write != tomoyo_write_domain_policy &&
2072             !tomoyo_is_policy_manager())
2073                 return -EPERM;
2074         if (mutex_lock_interruptible(&head->io_sem))
2075                 return -EINTR;
2076         /* Read a line and dispatch it to the policy handler. */
2077         while (avail_len > 0) {
2078                 char c;
2079                 if (head->write_avail >= head->writebuf_size - 1) {
2080                         error = -ENOMEM;
2081                         break;
2082                 } else if (get_user(c, buffer)) {
2083                         error = -EFAULT;
2084                         break;
2085                 }
2086                 buffer++;
2087                 avail_len--;
2088                 cp0[head->write_avail++] = c;
2089                 if (c != '\n')
2090                         continue;
2091                 cp0[head->write_avail - 1] = '\0';
2092                 head->write_avail = 0;
2093                 tomoyo_normalize_line(cp0);
2094                 head->write(head);
2095         }
2096         mutex_unlock(&head->io_sem);
2097         return error;
2098 }
2099
2100 /**
2101  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2102  *
2103  * @file: Pointer to "struct file".
2104  *
2105  * Releases memory and returns 0.
2106  *
2107  * Caller looses tomoyo_read_lock().
2108  */
2109 static int tomoyo_close_control(struct file *file)
2110 {
2111         struct tomoyo_io_buffer *head = file->private_data;
2112         const bool is_write = !!head->write_buf;
2113
2114         tomoyo_read_unlock(head->reader_idx);
2115         /* Release memory used for policy I/O. */
2116         kfree(head->read_buf);
2117         head->read_buf = NULL;
2118         kfree(head->write_buf);
2119         head->write_buf = NULL;
2120         kfree(head);
2121         head = NULL;
2122         file->private_data = NULL;
2123         if (is_write)
2124                 tomoyo_run_gc();
2125         return 0;
2126 }
2127
2128 /**
2129  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2130  *
2131  * @inode: Pointer to "struct inode".
2132  * @file:  Pointer to "struct file".
2133  *
2134  * Returns 0 on success, negative value otherwise.
2135  */
2136 static int tomoyo_open(struct inode *inode, struct file *file)
2137 {
2138         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2139                 - ((u8 *) NULL);
2140         return tomoyo_open_control(key, file);
2141 }
2142
2143 /**
2144  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2145  *
2146  * @inode: Pointer to "struct inode".
2147  * @file:  Pointer to "struct file".
2148  *
2149  * Returns 0 on success, negative value otherwise.
2150  */
2151 static int tomoyo_release(struct inode *inode, struct file *file)
2152 {
2153         return tomoyo_close_control(file);
2154 }
2155
2156 /**
2157  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2158  *
2159  * @file:  Pointer to "struct file".
2160  * @buf:   Pointer to buffer.
2161  * @count: Size of @buf.
2162  * @ppos:  Unused.
2163  *
2164  * Returns bytes read on success, negative value otherwise.
2165  */
2166 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2167                            loff_t *ppos)
2168 {
2169         return tomoyo_read_control(file, buf, count);
2170 }
2171
2172 /**
2173  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2174  *
2175  * @file:  Pointer to "struct file".
2176  * @buf:   Pointer to buffer.
2177  * @count: Size of @buf.
2178  * @ppos:  Unused.
2179  *
2180  * Returns @count on success, negative value otherwise.
2181  */
2182 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2183                             size_t count, loff_t *ppos)
2184 {
2185         return tomoyo_write_control(file, buf, count);
2186 }
2187
2188 /*
2189  * tomoyo_operations is a "struct file_operations" which is used for handling
2190  * /sys/kernel/security/tomoyo/ interface.
2191  *
2192  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2193  * See tomoyo_io_buffer for internals.
2194  */
2195 static const struct file_operations tomoyo_operations = {
2196         .open    = tomoyo_open,
2197         .release = tomoyo_release,
2198         .read    = tomoyo_read,
2199         .write   = tomoyo_write,
2200 };
2201
2202 /**
2203  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2204  *
2205  * @name:   The name of the interface file.
2206  * @mode:   The permission of the interface file.
2207  * @parent: The parent directory.
2208  * @key:    Type of interface.
2209  *
2210  * Returns nothing.
2211  */
2212 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2213                                        struct dentry *parent, const u8 key)
2214 {
2215         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2216                                &tomoyo_operations);
2217 }
2218
2219 /**
2220  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2221  *
2222  * Returns 0.
2223  */
2224 static int __init tomoyo_initerface_init(void)
2225 {
2226         struct dentry *tomoyo_dir;
2227
2228         /* Don't create securityfs entries unless registered. */
2229         if (current_cred()->security != &tomoyo_kernel_domain)
2230                 return 0;
2231
2232         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2233         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2234                             TOMOYO_DOMAINPOLICY);
2235         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2236                             TOMOYO_EXCEPTIONPOLICY);
2237         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2238                             TOMOYO_SELFDOMAIN);
2239         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2240                             TOMOYO_DOMAIN_STATUS);
2241         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2242                             TOMOYO_PROCESS_STATUS);
2243         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2244                             TOMOYO_MEMINFO);
2245         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2246                             TOMOYO_PROFILE);
2247         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2248                             TOMOYO_MANAGER);
2249         tomoyo_create_entry("version",          0400, tomoyo_dir,
2250                             TOMOYO_VERSION);
2251         return 0;
2252 }
2253
2254 fs_initcall(tomoyo_initerface_init);