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 "realpath.h"
  16 #include "common.h"
  17 #include "tomoyo.h"
  18
  19 /* Lock for protecting policy. */
  20 DEFINE_MUTEX(tomoyo_policy_lock);
  21
  22 /* Has loading policy done? */
  23 bool tomoyo_policy_loaded;
  24
  25 /* String table for functionality that takes 4 modes. */
  26 static const char *tomoyo_mode_4[4] = {
  27         "disabled", "learning", "permissive", "enforcing"
  28 };
  29 /* String table for functionality that takes 2 modes. */
  30 static const char *tomoyo_mode_2[4] = {
  31         "disabled", "enabled", "enabled", "enabled"
  32 };
  33
  34 /*
  35  * tomoyo_control_array is a static data which contains
  36  *
  37  *  (1) functionality name used by /sys/kernel/security/tomoyo/profile .
  38  *  (2) initial values for "struct tomoyo_profile".
  39  *  (3) max values for "struct tomoyo_profile".
  40  */
  41 static struct {
  42         const char *keyword;
  43         unsigned int current_value;
  44         const unsigned int max_value;
  45 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
  46         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
  47         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
  48         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
  49 };
  50
  51 /*
  52  * tomoyo_profile is a structure which is used for holding the mode of access
  53  * controls. TOMOYO has 4 modes: disabled, learning, permissive, enforcing.
  54  * An administrator can define up to 256 profiles.
  55  * The ->profile of "struct tomoyo_domain_info" is used for remembering
  56  * the profile's number (0 - 255) assigned to that domain.
  57  */
  58 static struct tomoyo_profile {
  59         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
  60         const struct tomoyo_path_info *comment;
  61 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
  62
  63 /* Permit policy management by non-root user? */
  64 static bool tomoyo_manage_by_non_root;
  65
  66 /* Utility functions. */
  67
  68 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
  69 static int tomoyo_open_control(const u8 type, struct file *file);
  70 /* Close /sys/kernel/security/tomoyo/ interface. */
  71 static int tomoyo_close_control(struct file *file);
  72 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
  73 static int tomoyo_read_control(struct file *file, char __user *buffer,
  74                                const int buffer_len);
  75 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
  76 static int tomoyo_write_control(struct file *file, const char __user *buffer,
  77                                 const int buffer_len);
  78
  79 /**
  80  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
  81  *
  82  * @str: Pointer to the string.
  83  *
  84  * Returns true if @str is a \ooo style octal value, false otherwise.
  85  *
  86  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
  87  * This function verifies that \ooo is in valid range.
  88  */
  89 static inline bool tomoyo_is_byte_range(const char *str)
  90 {
  91         return *str >= '0' && *str++ <= '3' &&
  92                 *str >= '0' && *str++ <= '7' &&
  93                 *str >= '0' && *str <= '7';
  94 }
  95
  96 /**
  97  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
  98  *
  99  * @c: The character to check.
 100  *
 101  * Returns true if @c is an alphabet character, false otherwise.
 102  */
 103 static inline bool tomoyo_is_alphabet_char(const char c)
 104 {
 105         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 106 }
 107
 108 /**
 109  * tomoyo_make_byte - Make byte value from three octal characters.
 110  *
 111  * @c1: The first character.
 112  * @c2: The second character.
 113  * @c3: The third character.
 114  *
 115  * Returns byte value.
 116  */
 117 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 118 {
 119         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 120 }
 121
 122 /**
 123  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 124  *
 125  * @src:  Pointer to pointer to the string.
 126  * @find: Pointer to the keyword.
 127  *
 128  * Returns true if @src starts with @find, false otherwise.
 129  *
 130  * The @src is updated to point the first character after the @find
 131  * if @src starts with @find.
 132  */
 133 static bool tomoyo_str_starts(char **src, const char *find)
 134 {
 135         const int len = strlen(find);
 136         char *tmp = *src;
 137
 138         if (strncmp(tmp, find, len))
 139                 return false;
 140         tmp += len;
 141         *src = tmp;
 142         return true;
 143 }
 144
 145 /**
 146  * tomoyo_normalize_line - Format string.
 147  *
 148  * @buffer: The line to normalize.
 149  *
 150  * Leading and trailing whitespaces are removed.
 151  * Multiple whitespaces are packed into single space.
 152  *
 153  * Returns nothing.
 154  */
 155 static void tomoyo_normalize_line(unsigned char *buffer)
 156 {
 157         unsigned char *sp = buffer;
 158         unsigned char *dp = buffer;
 159         bool first = true;
 160
 161         while (tomoyo_is_invalid(*sp))
 162                 sp++;
 163         while (*sp) {
 164                 if (!first)
 165                         *dp++ = ' ';
 166                 first = false;
 167                 while (tomoyo_is_valid(*sp))
 168                         *dp++ = *sp++;
 169                 while (tomoyo_is_invalid(*sp))
 170                         sp++;
 171         }
 172         *dp = '\0';
 173 }
 174
 175 /**
 176  * tomoyo_is_correct_path - Validate a pathname.
 177  * @filename:     The pathname to check.
 178  * @start_type:   Should the pathname start with '/'?
 179  *                1 = must / -1 = must not / 0 = don't care
 180  * @pattern_type: Can the pathname contain a wildcard?
 181  *                1 = must / -1 = must not / 0 = don't care
 182  * @end_type:     Should the pathname end with '/'?
 183  *                1 = must / -1 = must not / 0 = don't care
 184  * @function:     The name of function calling me.
 185  *
 186  * Check whether the given filename follows the naming rules.
 187  * Returns true if @filename follows the naming rules, false otherwise.
 188  */
 189 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 190                             const s8 pattern_type, const s8 end_type,
 191                             const char *function)
 192 {
 193         const char *const start = filename;
 194         bool in_repetition = false;
 195         bool contains_pattern = false;
 196         unsigned char c;
 197         unsigned char d;
 198         unsigned char e;
 199         const char *original_filename = filename;
 200
 201         if (!filename)
 202                 goto out;
 203         c = *filename;
 204         if (start_type == 1) { /* Must start with '/' */
 205                 if (c != '/')
 206                         goto out;
 207         } else if (start_type == -1) { /* Must not start with '/' */
 208                 if (c == '/')
 209                         goto out;
 210         }
 211         if (c)
 212                 c = *(filename + strlen(filename) - 1);
 213         if (end_type == 1) { /* Must end with '/' */
 214                 if (c != '/')
 215                         goto out;
 216         } else if (end_type == -1) { /* Must not end with '/' */
 217                 if (c == '/')
 218                         goto out;
 219         }
 220         while (1) {
 221                 c = *filename++;
 222                 if (!c)
 223                         break;
 224                 if (c == '\\') {
 225                         c = *filename++;
 226                         switch (c) {
 227                         case '\\':  /* "\\" */
 228                                 continue;
 229                         case '$':   /* "\$" */
 230                         case '+':   /* "\+" */
 231                         case '?':   /* "\?" */
 232                         case '*':   /* "\*" */
 233                         case '@':   /* "\@" */
 234                         case 'x':   /* "\x" */
 235                         case 'X':   /* "\X" */
 236                         case 'a':   /* "\a" */
 237                         case 'A':   /* "\A" */
 238                         case '-':   /* "\-" */
 239                                 if (pattern_type == -1)
 240                                         break; /* Must not contain pattern */
 241                                 contains_pattern = true;
 242                                 continue;
 243                         case '{':   /* "/\{" */
 244                                 if (filename - 3 < start ||
 245                                     *(filename - 3) != '/')
 246                                         break;
 247                                 if (pattern_type == -1)
 248                                         break; /* Must not contain pattern */
 249                                 contains_pattern = true;
 250                                 in_repetition = true;
 251                                 continue;
 252                         case '}':   /* "\}/" */
 253                                 if (*filename != '/')
 254                                         break;
 255                                 if (!in_repetition)
 256                                         break;
 257                                 in_repetition = false;
 258                                 continue;
 259                         case '0':   /* "\ooo" */
 260                         case '1':
 261                         case '2':
 262                         case '3':
 263                                 d = *filename++;
 264                                 if (d < '0' || d > '7')
 265                                         break;
 266                                 e = *filename++;
 267                                 if (e < '0' || e > '7')
 268                                         break;
 269                                 c = tomoyo_make_byte(c, d, e);
 270                                 if (tomoyo_is_invalid(c))
 271                                         continue; /* pattern is not \000 */
 272                         }
 273                         goto out;
 274                 } else if (in_repetition && c == '/') {
 275                         goto out;
 276                 } else if (tomoyo_is_invalid(c)) {
 277                         goto out;
 278                 }
 279         }
 280         if (pattern_type == 1) { /* Must contain pattern */
 281                 if (!contains_pattern)
 282                         goto out;
 283         }
 284         if (in_repetition)
 285                 goto out;
 286         return true;
 287  out:
 288         printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function,
 289                original_filename);
 290         return false;
 291 }
 292
 293 /**
 294  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 295  * @domainname:   The domainname to check.
 296  * @function:     The name of function calling me.
 297  *
 298  * Returns true if @domainname follows the naming rules, false otherwise.
 299  */
 300 bool tomoyo_is_correct_domain(const unsigned char *domainname,
 301                               const char *function)
 302 {
 303         unsigned char c;
 304         unsigned char d;
 305         unsigned char e;
 306         const char *org_domainname = domainname;
 307
 308         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 309                                    TOMOYO_ROOT_NAME_LEN))
 310                 goto out;
 311         domainname += TOMOYO_ROOT_NAME_LEN;
 312         if (!*domainname)
 313                 return true;
 314         do {
 315                 if (*domainname++ != ' ')
 316                         goto out;
 317                 if (*domainname++ != '/')
 318                         goto out;
 319                 while ((c = *domainname) != '\0' && c != ' ') {
 320                         domainname++;
 321                         if (c == '\\') {
 322                                 c = *domainname++;
 323                                 switch ((c)) {
 324                                 case '\\':  /* "\\" */
 325                                         continue;
 326                                 case '0':   /* "\ooo" */
 327                                 case '1':
 328                                 case '2':
 329                                 case '3':
 330                                         d = *domainname++;
 331                                         if (d < '0' || d > '7')
 332                                                 break;
 333                                         e = *domainname++;
 334                                         if (e < '0' || e > '7')
 335                                                 break;
 336                                         c = tomoyo_make_byte(c, d, e);
 337                                         if (tomoyo_is_invalid(c))
 338                                                 /* pattern is not \000 */
 339                                                 continue;
 340                                 }
 341                                 goto out;
 342                         } else if (tomoyo_is_invalid(c)) {
 343                                 goto out;
 344                         }
 345                 }
 346         } while (*domainname);
 347         return true;
 348  out:
 349         printk(KERN_DEBUG "%s: Invalid domainname '%s'\n", function,
 350                org_domainname);
 351         return false;
 352 }
 353
 354 /**
 355  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 356  *
 357  * @buffer: The token to check.
 358  *
 359  * Returns true if @buffer possibly be a domainname, false otherwise.
 360  */
 361 bool tomoyo_is_domain_def(const unsigned char *buffer)
 362 {
 363         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 364 }
 365
 366 /**
 367  * tomoyo_find_domain - Find a domain by the given name.
 368  *
 369  * @domainname: The domainname to find.
 370  *
 371  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 372  *
 373  * Caller holds tomoyo_read_lock().
 374  */
 375 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 376 {
 377         struct tomoyo_domain_info *domain;
 378         struct tomoyo_path_info name;
 379
 380         name.name = domainname;
 381         tomoyo_fill_path_info(&name);
 382         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 383                 if (!domain->is_deleted &&
 384                     !tomoyo_pathcmp(&name, domain->domainname))
 385                         return domain;
 386         }
 387         return NULL;
 388 }
 389
 390 /**
 391  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 392  *
 393  * @filename: The string to evaluate.
 394  *
 395  * Returns the initial length without a pattern in @filename.
 396  */
 397 static int tomoyo_const_part_length(const char *filename)
 398 {
 399         char c;
 400         int len = 0;
 401
 402         if (!filename)
 403                 return 0;
 404         while ((c = *filename++) != '\0') {
 405                 if (c != '\\') {
 406                         len++;
 407                         continue;
 408                 }
 409                 c = *filename++;
 410                 switch (c) {
 411                 case '\\':  /* "\\" */
 412                         len += 2;
 413                         continue;
 414                 case '0':   /* "\ooo" */
 415                 case '1':
 416                 case '2':
 417                 case '3':
 418                         c = *filename++;
 419                         if (c < '0' || c > '7')
 420                                 break;
 421                         c = *filename++;
 422                         if (c < '0' || c > '7')
 423                                 break;
 424                         len += 4;
 425                         continue;
 426                 }
 427                 break;
 428         }
 429         return len;
 430 }
 431
 432 /**
 433  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 434  *
 435  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 436  *
 437  * The caller sets "struct tomoyo_path_info"->name.
 438  */
 439 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 440 {
 441         const char *name = ptr->name;
 442         const int len = strlen(name);
 443
 444         ptr->const_len = tomoyo_const_part_length(name);
 445         ptr->is_dir = len && (name[len - 1] == '/');
 446         ptr->is_patterned = (ptr->const_len < len);
 447         ptr->hash = full_name_hash(name, len);
 448 }
 449
 450 /**
 451  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
 452  * and "\-" pattern.
 453  *
 454  * @filename:     The start of string to check.
 455  * @filename_end: The end of string to check.
 456  * @pattern:      The start of pattern to compare.
 457  * @pattern_end:  The end of pattern to compare.
 458  *
 459  * Returns true if @filename matches @pattern, false otherwise.
 460  */
 461 static bool tomoyo_file_matches_pattern2(const char *filename,
 462                                          const char *filename_end,
 463                                          const char *pattern,
 464                                          const char *pattern_end)
 465 {
 466         while (filename < filename_end && pattern < pattern_end) {
 467                 char c;
 468                 if (*pattern != '\\') {
 469                         if (*filename++ != *pattern++)
 470                                 return false;
 471                         continue;
 472                 }
 473                 c = *filename;
 474                 pattern++;
 475                 switch (*pattern) {
 476                         int i;
 477                         int j;
 478                 case '?':
 479                         if (c == '/') {
 480                                 return false;
 481                         } else if (c == '\\') {
 482                                 if (filename[1] == '\\')
 483                                         filename++;
 484                                 else if (tomoyo_is_byte_range(filename + 1))
 485                                         filename += 3;
 486                                 else
 487                                         return false;
 488                         }
 489                         break;
 490                 case '\\':
 491                         if (c != '\\')
 492                                 return false;
 493                         if (*++filename != '\\')
 494                                 return false;
 495                         break;
 496                 case '+':
 497                         if (!isdigit(c))
 498                                 return false;
 499                         break;
 500                 case 'x':
 501                         if (!isxdigit(c))
 502                                 return false;
 503                         break;
 504                 case 'a':
 505                         if (!tomoyo_is_alphabet_char(c))
 506                                 return false;
 507                         break;
 508                 case '0':
 509                 case '1':
 510                 case '2':
 511                 case '3':
 512                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 513                             && strncmp(filename + 1, pattern, 3) == 0) {
 514                                 filename += 3;
 515                                 pattern += 2;
 516                                 break;
 517                         }
 518                         return false; /* Not matched. */
 519                 case '*':
 520                 case '@':
 521                         for (i = 0; i <= filename_end - filename; i++) {
 522                                 if (tomoyo_file_matches_pattern2(
 523                                                     filename + i, filename_end,
 524                                                     pattern + 1, pattern_end))
 525                                         return true;
 526                                 c = filename[i];
 527                                 if (c == '.' && *pattern == '@')
 528                                         break;
 529                                 if (c != '\\')
 530                                         continue;
 531                                 if (filename[i + 1] == '\\')
 532                                         i++;
 533                                 else if (tomoyo_is_byte_range(filename + i + 1))
 534                                         i += 3;
 535                                 else
 536                                         break; /* Bad pattern. */
 537                         }
 538                         return false; /* Not matched. */
 539                 default:
 540                         j = 0;
 541                         c = *pattern;
 542                         if (c == '$') {
 543                                 while (isdigit(filename[j]))
 544                                         j++;
 545                         } else if (c == 'X') {
 546                                 while (isxdigit(filename[j]))
 547                                         j++;
 548                         } else if (c == 'A') {
 549                                 while (tomoyo_is_alphabet_char(filename[j]))
 550                                         j++;
 551                         }
 552                         for (i = 1; i <= j; i++) {
 553                                 if (tomoyo_file_matches_pattern2(
 554                                                     filename + i, filename_end,
 555                                                     pattern + 1, pattern_end))
 556                                         return true;
 557                         }
 558                         return false; /* Not matched or bad pattern. */
 559                 }
 560                 filename++;
 561                 pattern++;
 562         }
 563         while (*pattern == '\\' &&
 564                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 565                 pattern += 2;
 566         return filename == filename_end && pattern == pattern_end;
 567 }
 568
 569 /**
 570  * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
 571  *
 572  * @filename:     The start of string to check.
 573  * @filename_end: The end of string to check.
 574  * @pattern:      The start of pattern to compare.
 575  * @pattern_end:  The end of pattern to compare.
 576  *
 577  * Returns true if @filename matches @pattern, false otherwise.
 578  */
 579 static bool tomoyo_file_matches_pattern(const char *filename,
 580                                            const char *filename_end,
 581                                            const char *pattern,
 582                                            const char *pattern_end)
 583 {
 584         const char *pattern_start = pattern;
 585         bool first = true;
 586         bool result;
 587
 588         while (pattern < pattern_end - 1) {
 589                 /* Split at "\-" pattern. */
 590                 if (*pattern++ != '\\' || *pattern++ != '-')
 591                         continue;
 592                 result = tomoyo_file_matches_pattern2(filename,
 593                                                       filename_end,
 594                                                       pattern_start,
 595                                                       pattern - 2);
 596                 if (first)
 597                         result = !result;
 598                 if (result)
 599                         return false;
 600                 first = false;
 601                 pattern_start = pattern;
 602         }
 603         result = tomoyo_file_matches_pattern2(filename, filename_end,
 604                                               pattern_start, pattern_end);
 605         return first ? result : !result;
 606 }
 607
 608 /**
 609  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 610  *
 611  * @f: The start of string to check.
 612  * @p: The start of pattern to compare.
 613  *
 614  * Returns true if @f matches @p, false otherwise.
 615  */
 616 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 617 {
 618         const char *f_delimiter;
 619         const char *p_delimiter;
 620
 621         while (*f && *p) {
 622                 f_delimiter = strchr(f, '/');
 623                 if (!f_delimiter)
 624                         f_delimiter = f + strlen(f);
 625                 p_delimiter = strchr(p, '/');
 626                 if (!p_delimiter)
 627                         p_delimiter = p + strlen(p);
 628                 if (*p == '\\' && *(p + 1) == '{')
 629                         goto recursive;
 630                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 631                                                  p_delimiter))
 632                         return false;
 633                 f = f_delimiter;
 634                 if (*f)
 635                         f++;
 636                 p = p_delimiter;
 637                 if (*p)
 638                         p++;
 639         }
 640         /* Ignore trailing "\*" and "\@" in @pattern. */
 641         while (*p == '\\' &&
 642                (*(p + 1) == '*' || *(p + 1) == '@'))
 643                 p += 2;
 644         return !*f && !*p;
 645  recursive:
 646         /*
 647          * The "\{" pattern is permitted only after '/' character.
 648          * This guarantees that below "*(p - 1)" is safe.
 649          * Also, the "\}" pattern is permitted only before '/' character
 650          * so that "\{" + "\}" pair will not break the "\-" operator.
 651          */
 652         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 653             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 654                 return false; /* Bad pattern. */
 655         do {
 656                 /* Compare current component with pattern. */
 657                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 658                                                  p_delimiter - 2))
 659                         break;
 660                 /* Proceed to next component. */
 661                 f = f_delimiter;
 662                 if (!*f)
 663                         break;
 664                 f++;
 665                 /* Continue comparison. */
 666                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 667                         return true;
 668                 f_delimiter = strchr(f, '/');
 669         } while (f_delimiter);
 670         return false; /* Not matched. */
 671 }
 672
 673 /**
 674  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 675  *
 676  * @filename: The filename to check.
 677  * @pattern:  The pattern to compare.
 678  *
 679  * Returns true if matches, false otherwise.
 680  *
 681  * The following patterns are available.
 682  *   \\     \ itself.
 683  *   \ooo   Octal representation of a byte.
 684  *   \*     Zero or more repetitions of characters other than '/'.
 685  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 686  *   \?     1 byte character other than '/'.
 687  *   \$     One or more repetitions of decimal digits.
 688  *   \+     1 decimal digit.
 689  *   \X     One or more repetitions of hexadecimal digits.
 690  *   \x     1 hexadecimal digit.
 691  *   \A     One or more repetitions of alphabet characters.
 692  *   \a     1 alphabet character.
 693  *
 694  *   \-     Subtraction operator.
 695  *
 696  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 697  *               /dir/dir/dir/ ).
 698  */
 699 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 700                                  const struct tomoyo_path_info *pattern)
 701 {
 702         const char *f = filename->name;
 703         const char *p = pattern->name;
 704         const int len = pattern->const_len;
 705
 706         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 707         if (!pattern->is_patterned)
 708                 return !tomoyo_pathcmp(filename, pattern);
 709         /* Don't compare directory and non-directory. */
 710         if (filename->is_dir != pattern->is_dir)
 711                 return false;
 712         /* Compare the initial length without patterns. */
 713         if (strncmp(f, p, len))
 714                 return false;
 715         f += len;
 716         p += len;
 717         return tomoyo_path_matches_pattern2(f, p);
 718 }
 719
 720 /**
 721  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 722  *
 723  * @head: Pointer to "struct tomoyo_io_buffer".
 724  * @fmt:  The printf()'s format string, followed by parameters.
 725  *
 726  * Returns true if output was written, false otherwise.
 727  *
 728  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 729  */
 730 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 731 {
 732         va_list args;
 733         int len;
 734         int pos = head->read_avail;
 735         int size = head->readbuf_size - pos;
 736
 737         if (size <= 0)
 738                 return false;
 739         va_start(args, fmt);
 740         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 741         va_end(args);
 742         if (pos + len >= head->readbuf_size)
 743                 return false;
 744         head->read_avail += len;
 745         return true;
 746 }
 747
 748 /**
 749  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 750  *
 751  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 752  *
 753  * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
 754  * if this function didn't return NULL.
 755  */
 756 static const char *tomoyo_get_exe(void)
 757 {
 758         struct mm_struct *mm = current->mm;
 759         struct vm_area_struct *vma;
 760         const char *cp = NULL;
 761
 762         if (!mm)
 763                 return NULL;
 764         down_read(&mm->mmap_sem);
 765         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 766                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 767                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 768                         break;
 769                 }
 770         }
 771         up_read(&mm->mmap_sem);
 772         return cp;
 773 }
 774
 775 /**
 776  * tomoyo_get_msg - Get warning message.
 777  *
 778  * @is_enforce: Is it enforcing mode?
 779  *
 780  * Returns "ERROR" or "WARNING".
 781  */
 782 const char *tomoyo_get_msg(const bool is_enforce)
 783 {
 784         if (is_enforce)
 785                 return "ERROR";
 786         else
 787                 return "WARNING";
 788 }
 789
 790 /**
 791  * tomoyo_check_flags - Check mode for specified functionality.
 792  *
 793  * @domain: Pointer to "struct tomoyo_domain_info".
 794  * @index:  The functionality to check mode.
 795  *
 796  * TOMOYO checks only process context.
 797  * This code disables TOMOYO's enforcement in case the function is called from
 798  * interrupt context.
 799  */
 800 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 801                                 const u8 index)
 802 {
 803         const u8 profile = domain->profile;
 804
 805         if (WARN_ON(in_interrupt()))
 806                 return 0;
 807         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 808 #if TOMOYO_MAX_PROFILES != 256
 809                 && profile < TOMOYO_MAX_PROFILES
 810 #endif
 811                 && tomoyo_profile_ptr[profile] ?
 812                 tomoyo_profile_ptr[profile]->value[index] : 0;
 813 }
 814
 815 /**
 816  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 817  *
 818  * @domain: Pointer to "struct tomoyo_domain_info".
 819  *
 820  * Returns true if domain policy violation warning should be printed to
 821  * console.
 822  */
 823 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 824 {
 825         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 826 }
 827
 828 /**
 829  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 830  *
 831  * @domain: Pointer to "struct tomoyo_domain_info".
 832  *
 833  * Returns true if the domain is not exceeded quota, false otherwise.
 834  *
 835  * Caller holds tomoyo_read_lock().
 836  */
 837 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 838 {
 839         unsigned int count = 0;
 840         struct tomoyo_acl_info *ptr;
 841
 842         if (!domain)
 843                 return true;
 844         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 845                 if (ptr->type & TOMOYO_ACL_DELETED)
 846                         continue;
 847                 switch (tomoyo_acl_type2(ptr)) {
 848                         struct tomoyo_single_path_acl_record *acl;
 849                         u32 perm;
 850                         u8 i;
 851                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
 852                         acl = container_of(ptr,
 853                                            struct tomoyo_single_path_acl_record,
 854                                            head);
 855                         perm = acl->perm | (((u32) acl->perm_high) << 16);
 856                         for (i = 0; i < TOMOYO_MAX_SINGLE_PATH_OPERATION; i++)
 857                                 if (perm & (1 << i))
 858                                         count++;
 859                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL))
 860                                 count -= 2;
 861                         break;
 862                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
 863                         perm = container_of(ptr,
 864                                     struct tomoyo_double_path_acl_record,
 865                                             head)->perm;
 866                         for (i = 0; i < TOMOYO_MAX_DOUBLE_PATH_OPERATION; i++)
 867                                 if (perm & (1 << i))
 868                                         count++;
 869                         break;
 870                 }
 871         }
 872         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 873                 return true;
 874         if (!domain->quota_warned) {
 875                 domain->quota_warned = true;
 876                 printk(KERN_WARNING "TOMOYO-WARNING: "
 877                        "Domain '%s' has so many ACLs to hold. "
 878                        "Stopped learning mode.\n", domain->domainname->name);
 879         }
 880         return false;
 881 }
 882
 883 /**
 884  * tomoyo_find_or_assign_new_profile - Create a new profile.
 885  *
 886  * @profile: Profile number to create.
 887  *
 888  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 889  */
 890 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 891                                                                 int profile)
 892 {
 893         static DEFINE_MUTEX(lock);
 894         struct tomoyo_profile *ptr = NULL;
 895         int i;
 896
 897         if (profile >= TOMOYO_MAX_PROFILES)
 898                 return NULL;
 899         mutex_lock(&lock);
 900         ptr = tomoyo_profile_ptr[profile];
 901         if (ptr)
 902                 goto ok;
 903         ptr = kmalloc(sizeof(*ptr), GFP_KERNEL);
 904         if (!tomoyo_memory_ok(ptr)) {
 905                 kfree(ptr);
 906                 goto ok;
 907         }
 908         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 909                 ptr->value[i] = tomoyo_control_array[i].current_value;
 910         mb(); /* Avoid out-of-order execution. */
 911         tomoyo_profile_ptr[profile] = ptr;
 912  ok:
 913         mutex_unlock(&lock);
 914         return ptr;
 915 }
 916
 917 /**
 918  * tomoyo_write_profile - Write to profile table.
 919  *
 920  * @head: Pointer to "struct tomoyo_io_buffer".
 921  *
 922  * Returns 0 on success, negative value otherwise.
 923  */
 924 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 925 {
 926         char *data = head->write_buf;
 927         unsigned int i;
 928         unsigned int value;
 929         char *cp;
 930         struct tomoyo_profile *profile;
 931         unsigned long num;
 932
 933         cp = strchr(data, '-');
 934         if (cp)
 935                 *cp = '\0';
 936         if (strict_strtoul(data, 10, &num))
 937                 return -EINVAL;
 938         if (cp)
 939                 data = cp + 1;
 940         profile = tomoyo_find_or_assign_new_profile(num);
 941         if (!profile)
 942                 return -EINVAL;
 943         cp = strchr(data, '=');
 944         if (!cp)
 945                 return -EINVAL;
 946         *cp = '\0';
 947         if (!strcmp(data, "COMMENT")) {
 948                 profile->comment = tomoyo_save_name(cp + 1);
 949                 return 0;
 950         }
 951         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 952                 if (strcmp(data, tomoyo_control_array[i].keyword))
 953                         continue;
 954                 if (sscanf(cp + 1, "%u", &value) != 1) {
 955                         int j;
 956                         const char **modes;
 957                         switch (i) {
 958                         case TOMOYO_VERBOSE:
 959                                 modes = tomoyo_mode_2;
 960                                 break;
 961                         default:
 962                                 modes = tomoyo_mode_4;
 963                                 break;
 964                         }
 965                         for (j = 0; j < 4; j++) {
 966                                 if (strcmp(cp + 1, modes[j]))
 967                                         continue;
 968                                 value = j;
 969                                 break;
 970                         }
 971                         if (j == 4)
 972                                 return -EINVAL;
 973                 } else if (value > tomoyo_control_array[i].max_value) {
 974                         value = tomoyo_control_array[i].max_value;
 975                 }
 976                 profile->value[i] = value;
 977                 return 0;
 978         }
 979         return -EINVAL;
 980 }
 981
 982 /**
 983  * tomoyo_read_profile - Read from profile table.
 984  *
 985  * @head: Pointer to "struct tomoyo_io_buffer".
 986  *
 987  * Returns 0.
 988  */
 989 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 990 {
 991         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 992         int step;
 993
 994         if (head->read_eof)
 995                 return 0;
 996         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 997              step++) {
 998                 const u8 index = step / total;
 999                 u8 type = step % total;
1000                 const struct tomoyo_profile *profile
1001                         = tomoyo_profile_ptr[index];
1002                 head->read_step = step;
1003                 if (!profile)
1004                         continue;
1005                 if (!type) { /* Print profile' comment tag. */
1006                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
1007                                               index, profile->comment ?
1008                                               profile->comment->name : ""))
1009                                 break;
1010                         continue;
1011                 }
1012                 type--;
1013                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1014                         const unsigned int value = profile->value[type];
1015                         const char **modes = NULL;
1016                         const char *keyword
1017                                 = tomoyo_control_array[type].keyword;
1018                         switch (tomoyo_control_array[type].max_value) {
1019                         case 3:
1020                                 modes = tomoyo_mode_4;
1021                                 break;
1022                         case 1:
1023                                 modes = tomoyo_mode_2;
1024                                 break;
1025                         }
1026                         if (modes) {
1027                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1028                                                       keyword, modes[value]))
1029                                         break;
1030                         } else {
1031                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1032                                                       keyword, value))
1033                                         break;
1034                         }
1035                 }
1036         }
1037         if (step == TOMOYO_MAX_PROFILES * total)
1038                 head->read_eof = true;
1039         return 0;
1040 }
1041
1042 /*
1043  * tomoyo_policy_manager_entry is a structure which is used for holding list of
1044  * domainnames or programs which are permitted to modify configuration via
1045  * /sys/kernel/security/tomoyo/ interface.
1046  * It has following fields.
1047  *
1048  *  (1) "list" which is linked to tomoyo_policy_manager_list .
1049  *  (2) "manager" is a domainname or a program's pathname.
1050  *  (3) "is_domain" is a bool which is true if "manager" is a domainname, false
1051  *      otherwise.
1052  *  (4) "is_deleted" is a bool which is true if marked as deleted, false
1053  *      otherwise.
1054  */
1055 struct tomoyo_policy_manager_entry {
1056         struct list_head list;
1057         /* A path to program or a domainname. */
1058         const struct tomoyo_path_info *manager;
1059         bool is_domain;  /* True if manager is a domainname. */
1060         bool is_deleted; /* True if this entry is deleted. */
1061 };
1062
1063 /*
1064  * tomoyo_policy_manager_list is used for holding list of domainnames or
1065  * programs which are permitted to modify configuration via
1066  * /sys/kernel/security/tomoyo/ interface.
1067  *
1068  * An entry is added by
1069  *
1070  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1071  *                                        /sys/kernel/security/tomoyo/manager
1072  *  (if you want to specify by a domainname)
1073  *
1074  *  or
1075  *
1076  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1077  *  (if you want to specify by a program's location)
1078  *
1079  * and is deleted by
1080  *
1081  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1082  *                                        /sys/kernel/security/tomoyo/manager
1083  *
1084  *  or
1085  *
1086  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1087  *                                        /sys/kernel/security/tomoyo/manager
1088  *
1089  * and all entries are retrieved by
1090  *
1091  * # cat /sys/kernel/security/tomoyo/manager
1092  */
1093 static LIST_HEAD(tomoyo_policy_manager_list);
1094
1095 /**
1096  * tomoyo_update_manager_entry - Add a manager entry.
1097  *
1098  * @manager:   The path to manager or the domainnamme.
1099  * @is_delete: True if it is a delete request.
1100  *
1101  * Returns 0 on success, negative value otherwise.
1102  *
1103  * Caller holds tomoyo_read_lock().
1104  */
1105 static int tomoyo_update_manager_entry(const char *manager,
1106                                        const bool is_delete)
1107 {
1108         struct tomoyo_policy_manager_entry *new_entry;
1109         struct tomoyo_policy_manager_entry *ptr;
1110         const struct tomoyo_path_info *saved_manager;
1111         int error = -ENOMEM;
1112         bool is_domain = false;
1113
1114         if (tomoyo_is_domain_def(manager)) {
1115                 if (!tomoyo_is_correct_domain(manager, __func__))
1116                         return -EINVAL;
1117                 is_domain = true;
1118         } else {
1119                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1120                         return -EINVAL;
1121         }
1122         saved_manager = tomoyo_save_name(manager);
1123         if (!saved_manager)
1124                 return -ENOMEM;
1125         new_entry = kmalloc(sizeof(*new_entry), GFP_KERNEL);
1126         mutex_lock(&tomoyo_policy_lock);
1127         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1128                 if (ptr->manager != saved_manager)
1129                         continue;
1130                 ptr->is_deleted = is_delete;
1131                 error = 0;
1132                 goto out;
1133         }
1134         if (is_delete) {
1135                 error = -ENOENT;
1136                 goto out;
1137         }
1138         if (!tomoyo_memory_ok(new_entry))
1139                 goto out;
1140         new_entry->manager = saved_manager;
1141         new_entry->is_domain = is_domain;
1142         list_add_tail_rcu(&new_entry->list, &tomoyo_policy_manager_list);
1143         new_entry = NULL;
1144         error = 0;
1145  out:
1146         mutex_unlock(&tomoyo_policy_lock);
1147         kfree(new_entry);
1148         return error;
1149 }
1150
1151 /**
1152  * tomoyo_write_manager_policy - Write manager policy.
1153  *
1154  * @head: Pointer to "struct tomoyo_io_buffer".
1155  *
1156  * Returns 0 on success, negative value otherwise.
1157  *
1158  * Caller holds tomoyo_read_lock().
1159  */
1160 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1161 {
1162         char *data = head->write_buf;
1163         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1164
1165         if (!strcmp(data, "manage_by_non_root")) {
1166                 tomoyo_manage_by_non_root = !is_delete;
1167                 return 0;
1168         }
1169         return tomoyo_update_manager_entry(data, is_delete);
1170 }
1171
1172 /**
1173  * tomoyo_read_manager_policy - Read manager policy.
1174  *
1175  * @head: Pointer to "struct tomoyo_io_buffer".
1176  *
1177  * Returns 0.
1178  *
1179  * Caller holds tomoyo_read_lock().
1180  */
1181 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1182 {
1183         struct list_head *pos;
1184         bool done = true;
1185
1186         if (head->read_eof)
1187                 return 0;
1188         list_for_each_cookie(pos, head->read_var2,
1189                              &tomoyo_policy_manager_list) {
1190                 struct tomoyo_policy_manager_entry *ptr;
1191                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1192                                  list);
1193                 if (ptr->is_deleted)
1194                         continue;
1195                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1196                 if (!done)
1197                         break;
1198         }
1199         head->read_eof = done;
1200         return 0;
1201 }
1202
1203 /**
1204  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1205  *
1206  * Returns true if the current process is permitted to modify policy
1207  * via /sys/kernel/security/tomoyo/ interface.
1208  *
1209  * Caller holds tomoyo_read_lock().
1210  */
1211 static bool tomoyo_is_policy_manager(void)
1212 {
1213         struct tomoyo_policy_manager_entry *ptr;
1214         const char *exe;
1215         const struct task_struct *task = current;
1216         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1217         bool found = false;
1218
1219         if (!tomoyo_policy_loaded)
1220                 return true;
1221         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1222                 return false;
1223         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1224                 if (!ptr->is_deleted && ptr->is_domain
1225                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1226                         found = true;
1227                         break;
1228                 }
1229         }
1230         if (found)
1231                 return true;
1232         exe = tomoyo_get_exe();
1233         if (!exe)
1234                 return false;
1235         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1236                 if (!ptr->is_deleted && !ptr->is_domain
1237                     && !strcmp(exe, ptr->manager->name)) {
1238                         found = true;
1239                         break;
1240                 }
1241         }
1242         if (!found) { /* Reduce error messages. */
1243                 static pid_t last_pid;
1244                 const pid_t pid = current->pid;
1245                 if (last_pid != pid) {
1246                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1247                                "update policies.\n", domainname->name, exe);
1248                         last_pid = pid;
1249                 }
1250         }
1251         tomoyo_free(exe);
1252         return found;
1253 }
1254
1255 /**
1256  * tomoyo_is_select_one - Parse select command.
1257  *
1258  * @head: Pointer to "struct tomoyo_io_buffer".
1259  * @data: String to parse.
1260  *
1261  * Returns true on success, false otherwise.
1262  *
1263  * Caller holds tomoyo_read_lock().
1264  */
1265 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1266                                  const char *data)
1267 {
1268         unsigned int pid;
1269         struct tomoyo_domain_info *domain = NULL;
1270
1271         if (sscanf(data, "pid=%u", &pid) == 1) {
1272                 struct task_struct *p;
1273                 read_lock(&tasklist_lock);
1274                 p = find_task_by_vpid(pid);
1275                 if (p)
1276                         domain = tomoyo_real_domain(p);
1277                 read_unlock(&tasklist_lock);
1278         } else if (!strncmp(data, "domain=", 7)) {
1279                 if (tomoyo_is_domain_def(data + 7))
1280                         domain = tomoyo_find_domain(data + 7);
1281         } else
1282                 return false;
1283         head->write_var1 = domain;
1284         /* Accessing read_buf is safe because head->io_sem is held. */
1285         if (!head->read_buf)
1286                 return true; /* Do nothing if open(O_WRONLY). */
1287         head->read_avail = 0;
1288         tomoyo_io_printf(head, "# select %s\n", data);
1289         head->read_single_domain = true;
1290         head->read_eof = !domain;
1291         if (domain) {
1292                 struct tomoyo_domain_info *d;
1293                 head->read_var1 = NULL;
1294                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1295                         if (d == domain)
1296                                 break;
1297                         head->read_var1 = &d->list;
1298                 }
1299                 head->read_var2 = NULL;
1300                 head->read_bit = 0;
1301                 head->read_step = 0;
1302                 if (domain->is_deleted)
1303                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1304         }
1305         return true;
1306 }
1307
1308 /**
1309  * tomoyo_delete_domain - Delete a domain.
1310  *
1311  * @domainname: The name of domain.
1312  *
1313  * Returns 0.
1314  *
1315  * Caller holds tomoyo_read_lock().
1316  */
1317 static int tomoyo_delete_domain(char *domainname)
1318 {
1319         struct tomoyo_domain_info *domain;
1320         struct tomoyo_path_info name;
1321
1322         name.name = domainname;
1323         tomoyo_fill_path_info(&name);
1324         mutex_lock(&tomoyo_policy_lock);
1325         /* Is there an active domain? */
1326         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1327                 /* Never delete tomoyo_kernel_domain */
1328                 if (domain == &tomoyo_kernel_domain)
1329                         continue;
1330                 if (domain->is_deleted ||
1331                     tomoyo_pathcmp(domain->domainname, &name))
1332                         continue;
1333                 domain->is_deleted = true;
1334                 break;
1335         }
1336         mutex_unlock(&tomoyo_policy_lock);
1337         return 0;
1338 }
1339
1340 /**
1341  * tomoyo_write_domain_policy - Write domain policy.
1342  *
1343  * @head: Pointer to "struct tomoyo_io_buffer".
1344  *
1345  * Returns 0 on success, negative value otherwise.
1346  *
1347  * Caller holds tomoyo_read_lock().
1348  */
1349 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1350 {
1351         char *data = head->write_buf;
1352         struct tomoyo_domain_info *domain = head->write_var1;
1353         bool is_delete = false;
1354         bool is_select = false;
1355         unsigned int profile;
1356
1357         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1358                 is_delete = true;
1359         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1360                 is_select = true;
1361         if (is_select && tomoyo_is_select_one(head, data))
1362                 return 0;
1363         /* Don't allow updating policies by non manager programs. */
1364         if (!tomoyo_is_policy_manager())
1365                 return -EPERM;
1366         if (tomoyo_is_domain_def(data)) {
1367                 domain = NULL;
1368                 if (is_delete)
1369                         tomoyo_delete_domain(data);
1370                 else if (is_select)
1371                         domain = tomoyo_find_domain(data);
1372                 else
1373                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1374                 head->write_var1 = domain;
1375                 return 0;
1376         }
1377         if (!domain)
1378                 return -EINVAL;
1379
1380         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1381             && profile < TOMOYO_MAX_PROFILES) {
1382                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1383                         domain->profile = (u8) profile;
1384                 return 0;
1385         }
1386         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1387                 tomoyo_set_domain_flag(domain, is_delete,
1388                                TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
1389                 return 0;
1390         }
1391         return tomoyo_write_file_policy(data, domain, is_delete);
1392 }
1393
1394 /**
1395  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1396  *
1397  * @head: Pointer to "struct tomoyo_io_buffer".
1398  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1399  *
1400  * Returns true on success, false otherwise.
1401  */
1402 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1403                                          struct tomoyo_single_path_acl_record *
1404                                          ptr)
1405 {
1406         int pos;
1407         u8 bit;
1408         const char *atmark = "";
1409         const char *filename;
1410         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1411
1412         filename = ptr->filename->name;
1413         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1414              bit++) {
1415                 const char *msg;
1416                 if (!(perm & (1 << bit)))
1417                         continue;
1418                 /* Print "read/write" instead of "read" and "write". */
1419                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1420                      bit == TOMOYO_TYPE_WRITE_ACL)
1421                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1422                         continue;
1423                 msg = tomoyo_sp2keyword(bit);
1424                 pos = head->read_avail;
1425                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1426                                       atmark, filename))
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_double_path_acl - Print a double path ACL entry.
1439  *
1440  * @head: Pointer to "struct tomoyo_io_buffer".
1441  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1442  *
1443  * Returns true on success, false otherwise.
1444  */
1445 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1446                                          struct tomoyo_double_path_acl_record *
1447                                          ptr)
1448 {
1449         int pos;
1450         const char *atmark1 = "";
1451         const char *atmark2 = "";
1452         const char *filename1;
1453         const char *filename2;
1454         const u8 perm = ptr->perm;
1455         u8 bit;
1456
1457         filename1 = ptr->filename1->name;
1458         filename2 = ptr->filename2->name;
1459         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1460              bit++) {
1461                 const char *msg;
1462                 if (!(perm & (1 << bit)))
1463                         continue;
1464                 msg = tomoyo_dp2keyword(bit);
1465                 pos = head->read_avail;
1466                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1467                                       atmark1, filename1, atmark2, filename2))
1468                         goto out;
1469         }
1470         head->read_bit = 0;
1471         return true;
1472  out:
1473         head->read_bit = bit;
1474         head->read_avail = pos;
1475         return false;
1476 }
1477
1478 /**
1479  * tomoyo_print_entry - Print an ACL entry.
1480  *
1481  * @head: Pointer to "struct tomoyo_io_buffer".
1482  * @ptr:  Pointer to an ACL entry.
1483  *
1484  * Returns true on success, false otherwise.
1485  */
1486 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1487                                struct tomoyo_acl_info *ptr)
1488 {
1489         const u8 acl_type = tomoyo_acl_type2(ptr);
1490
1491         if (acl_type & TOMOYO_ACL_DELETED)
1492                 return true;
1493         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1494                 struct tomoyo_single_path_acl_record *acl
1495                         = container_of(ptr,
1496                                        struct tomoyo_single_path_acl_record,
1497                                        head);
1498                 return tomoyo_print_single_path_acl(head, acl);
1499         }
1500         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1501                 struct tomoyo_double_path_acl_record *acl
1502                         = container_of(ptr,
1503                                        struct tomoyo_double_path_acl_record,
1504                                        head);
1505                 return tomoyo_print_double_path_acl(head, acl);
1506         }
1507         BUG(); /* This must not happen. */
1508         return false;
1509 }
1510
1511 /**
1512  * tomoyo_read_domain_policy - Read domain policy.
1513  *
1514  * @head: Pointer to "struct tomoyo_io_buffer".
1515  *
1516  * Returns 0.
1517  *
1518  * Caller holds tomoyo_read_lock().
1519  */
1520 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1521 {
1522         struct list_head *dpos;
1523         struct list_head *apos;
1524         bool done = true;
1525
1526         if (head->read_eof)
1527                 return 0;
1528         if (head->read_step == 0)
1529                 head->read_step = 1;
1530         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1531                 struct tomoyo_domain_info *domain;
1532                 const char *quota_exceeded = "";
1533                 const char *transition_failed = "";
1534                 const char *ignore_global_allow_read = "";
1535                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1536                 if (head->read_step != 1)
1537                         goto acl_loop;
1538                 if (domain->is_deleted && !head->read_single_domain)
1539                         continue;
1540                 /* Print domainname and flags. */
1541                 if (domain->quota_warned)
1542                         quota_exceeded = "quota_exceeded\n";
1543                 if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
1544                         transition_failed = "transition_failed\n";
1545                 if (domain->flags &
1546                     TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
1547                         ignore_global_allow_read
1548                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1549                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1550                                         "%u\n%s%s%s\n",
1551                                         domain->domainname->name,
1552                                         domain->profile, quota_exceeded,
1553                                         transition_failed,
1554                                         ignore_global_allow_read);
1555                 if (!done)
1556                         break;
1557                 head->read_step = 2;
1558 acl_loop:
1559                 if (head->read_step == 3)
1560                         goto tail_mark;
1561                 /* Print ACL entries in the domain. */
1562                 list_for_each_cookie(apos, head->read_var2,
1563                                      &domain->acl_info_list) {
1564                         struct tomoyo_acl_info *ptr
1565                                 = list_entry(apos, struct tomoyo_acl_info,
1566                                              list);
1567                         done = tomoyo_print_entry(head, ptr);
1568                         if (!done)
1569                                 break;
1570                 }
1571                 if (!done)
1572                         break;
1573                 head->read_step = 3;
1574 tail_mark:
1575                 done = tomoyo_io_printf(head, "\n");
1576                 if (!done)
1577                         break;
1578                 head->read_step = 1;
1579                 if (head->read_single_domain)
1580                         break;
1581         }
1582         head->read_eof = done;
1583         return 0;
1584 }
1585
1586 /**
1587  * tomoyo_write_domain_profile - Assign profile for specified domain.
1588  *
1589  * @head: Pointer to "struct tomoyo_io_buffer".
1590  *
1591  * Returns 0 on success, -EINVAL otherwise.
1592  *
1593  * This is equivalent to doing
1594  *
1595  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1596  *     /usr/lib/ccs/loadpolicy -d
1597  *
1598  * Caller holds tomoyo_read_lock().
1599  */
1600 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1601 {
1602         char *data = head->write_buf;
1603         char *cp = strchr(data, ' ');
1604         struct tomoyo_domain_info *domain;
1605         unsigned long profile;
1606
1607         if (!cp)
1608                 return -EINVAL;
1609         *cp = '\0';
1610         domain = tomoyo_find_domain(cp + 1);
1611         if (strict_strtoul(data, 10, &profile))
1612                 return -EINVAL;
1613         if (domain && profile < TOMOYO_MAX_PROFILES
1614             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1615                 domain->profile = (u8) profile;
1616         return 0;
1617 }
1618
1619 /**
1620  * tomoyo_read_domain_profile - Read only domainname and profile.
1621  *
1622  * @head: Pointer to "struct tomoyo_io_buffer".
1623  *
1624  * Returns list of profile number and domainname pairs.
1625  *
1626  * This is equivalent to doing
1627  *
1628  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1629  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1630  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1631  *     print $2 " " domainname; domainname = ""; } } ; '
1632  *
1633  * Caller holds tomoyo_read_lock().
1634  */
1635 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1636 {
1637         struct list_head *pos;
1638         bool done = true;
1639
1640         if (head->read_eof)
1641                 return 0;
1642         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1643                 struct tomoyo_domain_info *domain;
1644                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1645                 if (domain->is_deleted)
1646                         continue;
1647                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1648                                         domain->domainname->name);
1649                 if (!done)
1650                         break;
1651         }
1652         head->read_eof = done;
1653         return 0;
1654 }
1655
1656 /**
1657  * tomoyo_write_pid: Specify PID to obtain domainname.
1658  *
1659  * @head: Pointer to "struct tomoyo_io_buffer".
1660  *
1661  * Returns 0.
1662  */
1663 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1664 {
1665         unsigned long pid;
1666         /* No error check. */
1667         strict_strtoul(head->write_buf, 10, &pid);
1668         head->read_step = (int) pid;
1669         head->read_eof = false;
1670         return 0;
1671 }
1672
1673 /**
1674  * tomoyo_read_pid - Get domainname of the specified PID.
1675  *
1676  * @head: Pointer to "struct tomoyo_io_buffer".
1677  *
1678  * Returns the domainname which the specified PID is in on success,
1679  * empty string otherwise.
1680  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1681  * using read()/write() interface rather than sysctl() interface.
1682  */
1683 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1684 {
1685         if (head->read_avail == 0 && !head->read_eof) {
1686                 const int pid = head->read_step;
1687                 struct task_struct *p;
1688                 struct tomoyo_domain_info *domain = NULL;
1689                 read_lock(&tasklist_lock);
1690                 p = find_task_by_vpid(pid);
1691                 if (p)
1692                         domain = tomoyo_real_domain(p);
1693                 read_unlock(&tasklist_lock);
1694                 if (domain)
1695                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1696                                          domain->domainname->name);
1697                 head->read_eof = true;
1698         }
1699         return 0;
1700 }
1701
1702 /**
1703  * tomoyo_write_exception_policy - Write exception policy.
1704  *
1705  * @head: Pointer to "struct tomoyo_io_buffer".
1706  *
1707  * Returns 0 on success, negative value otherwise.
1708  *
1709  * Caller holds tomoyo_read_lock().
1710  */
1711 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1712 {
1713         char *data = head->write_buf;
1714         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1715
1716         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1717                 return tomoyo_write_domain_keeper_policy(data, false,
1718                                                          is_delete);
1719         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1720                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1721         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1722                 return tomoyo_write_domain_initializer_policy(data, false,
1723                                                               is_delete);
1724         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1725                 return tomoyo_write_domain_initializer_policy(data, true,
1726                                                               is_delete);
1727         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1728                 return tomoyo_write_alias_policy(data, is_delete);
1729         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1730                 return tomoyo_write_globally_readable_policy(data, is_delete);
1731         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1732                 return tomoyo_write_pattern_policy(data, is_delete);
1733         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1734                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1735         return -EINVAL;
1736 }
1737
1738 /**
1739  * tomoyo_read_exception_policy - Read exception policy.
1740  *
1741  * @head: Pointer to "struct tomoyo_io_buffer".
1742  *
1743  * Returns 0 on success, -EINVAL otherwise.
1744  *
1745  * Caller holds tomoyo_read_lock().
1746  */
1747 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1748 {
1749         if (!head->read_eof) {
1750                 switch (head->read_step) {
1751                 case 0:
1752                         head->read_var2 = NULL;
1753                         head->read_step = 1;
1754                 case 1:
1755                         if (!tomoyo_read_domain_keeper_policy(head))
1756                                 break;
1757                         head->read_var2 = NULL;
1758                         head->read_step = 2;
1759                 case 2:
1760                         if (!tomoyo_read_globally_readable_policy(head))
1761                                 break;
1762                         head->read_var2 = NULL;
1763                         head->read_step = 3;
1764                 case 3:
1765                         head->read_var2 = NULL;
1766                         head->read_step = 4;
1767                 case 4:
1768                         if (!tomoyo_read_domain_initializer_policy(head))
1769                                 break;
1770                         head->read_var2 = NULL;
1771                         head->read_step = 5;
1772                 case 5:
1773                         if (!tomoyo_read_alias_policy(head))
1774                                 break;
1775                         head->read_var2 = NULL;
1776                         head->read_step = 6;
1777                 case 6:
1778                         head->read_var2 = NULL;
1779                         head->read_step = 7;
1780                 case 7:
1781                         if (!tomoyo_read_file_pattern(head))
1782                                 break;
1783                         head->read_var2 = NULL;
1784                         head->read_step = 8;
1785                 case 8:
1786                         if (!tomoyo_read_no_rewrite_policy(head))
1787                                 break;
1788                         head->read_var2 = NULL;
1789                         head->read_step = 9;
1790                 case 9:
1791                         head->read_eof = true;
1792                         break;
1793                 default:
1794                         return -EINVAL;
1795                 }
1796         }
1797         return 0;
1798 }
1799
1800 /* path to policy loader */
1801 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1802
1803 /**
1804  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1805  *
1806  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1807  */
1808 static bool tomoyo_policy_loader_exists(void)
1809 {
1810         /*
1811          * Don't activate MAC if the policy loader doesn't exist.
1812          * If the initrd includes /sbin/init but real-root-dev has not
1813          * mounted on / yet, activating MAC will block the system since
1814          * policies are not loaded yet.
1815          * Thus, let do_execve() call this function everytime.
1816          */
1817         struct path path;
1818
1819         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1820                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1821                        "since %s doesn't exist.\n", tomoyo_loader);
1822                 return false;
1823         }
1824         path_put(&path);
1825         return true;
1826 }
1827
1828 /**
1829  * tomoyo_load_policy - Run external policy loader to load policy.
1830  *
1831  * @filename: The program about to start.
1832  *
1833  * This function checks whether @filename is /sbin/init , and if so
1834  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1835  * and then continues invocation of /sbin/init.
1836  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1837  * writes to /sys/kernel/security/tomoyo/ interfaces.
1838  *
1839  * Returns nothing.
1840  */
1841 void tomoyo_load_policy(const char *filename)
1842 {
1843         char *argv[2];
1844         char *envp[3];
1845
1846         if (tomoyo_policy_loaded)
1847                 return;
1848         /*
1849          * Check filename is /sbin/init or /sbin/tomoyo-start.
1850          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1851          * be passed.
1852          * You can create /sbin/tomoyo-start by
1853          * "ln -s /bin/true /sbin/tomoyo-start".
1854          */
1855         if (strcmp(filename, "/sbin/init") &&
1856             strcmp(filename, "/sbin/tomoyo-start"))
1857                 return;
1858         if (!tomoyo_policy_loader_exists())
1859                 return;
1860
1861         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1862                tomoyo_loader);
1863         argv[0] = (char *) tomoyo_loader;
1864         argv[1] = NULL;
1865         envp[0] = "HOME=/";
1866         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1867         envp[2] = NULL;
1868         call_usermodehelper(argv[0], argv, envp, 1);
1869
1870         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1871         printk(KERN_INFO "Mandatory Access Control activated.\n");
1872         tomoyo_policy_loaded = true;
1873         { /* Check all profiles currently assigned to domains are defined. */
1874                 struct tomoyo_domain_info *domain;
1875                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1876                         const u8 profile = domain->profile;
1877                         if (tomoyo_profile_ptr[profile])
1878                                 continue;
1879                         panic("Profile %u (used by '%s') not defined.\n",
1880                               profile, domain->domainname->name);
1881                 }
1882         }
1883 }
1884
1885 /**
1886  * tomoyo_read_version: Get version.
1887  *
1888  * @head: Pointer to "struct tomoyo_io_buffer".
1889  *
1890  * Returns version information.
1891  */
1892 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1893 {
1894         if (!head->read_eof) {
1895                 tomoyo_io_printf(head, "2.2.0");
1896                 head->read_eof = true;
1897         }
1898         return 0;
1899 }
1900
1901 /**
1902  * tomoyo_read_self_domain - Get the current process's domainname.
1903  *
1904  * @head: Pointer to "struct tomoyo_io_buffer".
1905  *
1906  * Returns the current process's domainname.
1907  */
1908 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1909 {
1910         if (!head->read_eof) {
1911                 /*
1912                  * tomoyo_domain()->domainname != NULL
1913                  * because every process belongs to a domain and
1914                  * the domain's name cannot be NULL.
1915                  */
1916                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1917                 head->read_eof = true;
1918         }
1919         return 0;
1920 }
1921
1922 /**
1923  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1924  *
1925  * @type: Type of interface.
1926  * @file: Pointer to "struct file".
1927  *
1928  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1929  *
1930  * Caller acquires tomoyo_read_lock().
1931  */
1932 static int tomoyo_open_control(const u8 type, struct file *file)
1933 {
1934         struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
1935
1936         if (!head)
1937                 return -ENOMEM;
1938         mutex_init(&head->io_sem);
1939         switch (type) {
1940         case TOMOYO_DOMAINPOLICY:
1941                 /* /sys/kernel/security/tomoyo/domain_policy */
1942                 head->write = tomoyo_write_domain_policy;
1943                 head->read = tomoyo_read_domain_policy;
1944                 break;
1945         case TOMOYO_EXCEPTIONPOLICY:
1946                 /* /sys/kernel/security/tomoyo/exception_policy */
1947                 head->write = tomoyo_write_exception_policy;
1948                 head->read = tomoyo_read_exception_policy;
1949                 break;
1950         case TOMOYO_SELFDOMAIN:
1951                 /* /sys/kernel/security/tomoyo/self_domain */
1952                 head->read = tomoyo_read_self_domain;
1953                 break;
1954         case TOMOYO_DOMAIN_STATUS:
1955                 /* /sys/kernel/security/tomoyo/.domain_status */
1956                 head->write = tomoyo_write_domain_profile;
1957                 head->read = tomoyo_read_domain_profile;
1958                 break;
1959         case TOMOYO_PROCESS_STATUS:
1960                 /* /sys/kernel/security/tomoyo/.process_status */
1961                 head->write = tomoyo_write_pid;
1962                 head->read = tomoyo_read_pid;
1963                 break;
1964         case TOMOYO_VERSION:
1965                 /* /sys/kernel/security/tomoyo/version */
1966                 head->read = tomoyo_read_version;
1967                 head->readbuf_size = 128;
1968                 break;
1969         case TOMOYO_MEMINFO:
1970                 /* /sys/kernel/security/tomoyo/meminfo */
1971                 head->write = tomoyo_write_memory_quota;
1972                 head->read = tomoyo_read_memory_counter;
1973                 head->readbuf_size = 512;
1974                 break;
1975         case TOMOYO_PROFILE:
1976                 /* /sys/kernel/security/tomoyo/profile */
1977                 head->write = tomoyo_write_profile;
1978                 head->read = tomoyo_read_profile;
1979                 break;
1980         case TOMOYO_MANAGER:
1981                 /* /sys/kernel/security/tomoyo/manager */
1982                 head->write = tomoyo_write_manager_policy;
1983                 head->read = tomoyo_read_manager_policy;
1984                 break;
1985         }
1986         if (!(file->f_mode & FMODE_READ)) {
1987                 /*
1988                  * No need to allocate read_buf since it is not opened
1989                  * for reading.
1990                  */
1991                 head->read = NULL;
1992         } else {
1993                 if (!head->readbuf_size)
1994                         head->readbuf_size = 4096 * 2;
1995                 head->read_buf = tomoyo_alloc(head->readbuf_size);
1996                 if (!head->read_buf) {
1997                         tomoyo_free(head);
1998                         return -ENOMEM;
1999                 }
2000         }
2001         if (!(file->f_mode & FMODE_WRITE)) {
2002                 /*
2003                  * No need to allocate write_buf since it is not opened
2004                  * for writing.
2005                  */
2006                 head->write = NULL;
2007         } else if (head->write) {
2008                 head->writebuf_size = 4096 * 2;
2009                 head->write_buf = tomoyo_alloc(head->writebuf_size);
2010                 if (!head->write_buf) {
2011                         tomoyo_free(head->read_buf);
2012                         tomoyo_free(head);
2013                         return -ENOMEM;
2014                 }
2015         }
2016         head->reader_idx = tomoyo_read_lock();
2017         file->private_data = head;
2018         /*
2019          * Call the handler now if the file is
2020          * /sys/kernel/security/tomoyo/self_domain
2021          * so that the user can use
2022          * cat < /sys/kernel/security/tomoyo/self_domain"
2023          * to know the current process's domainname.
2024          */
2025         if (type == TOMOYO_SELFDOMAIN)
2026                 tomoyo_read_control(file, NULL, 0);
2027         return 0;
2028 }
2029
2030 /**
2031  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
2032  *
2033  * @file:       Pointer to "struct file".
2034  * @buffer:     Poiner to buffer to write to.
2035  * @buffer_len: Size of @buffer.
2036  *
2037  * Returns bytes read on success, negative value otherwise.
2038  *
2039  * Caller holds tomoyo_read_lock().
2040  */
2041 static int tomoyo_read_control(struct file *file, char __user *buffer,
2042                                const int buffer_len)
2043 {
2044         int len = 0;
2045         struct tomoyo_io_buffer *head = file->private_data;
2046         char *cp;
2047
2048         if (!head->read)
2049                 return -ENOSYS;
2050         if (mutex_lock_interruptible(&head->io_sem))
2051                 return -EINTR;
2052         /* Call the policy handler. */
2053         len = head->read(head);
2054         if (len < 0)
2055                 goto out;
2056         /* Write to buffer. */
2057         len = head->read_avail;
2058         if (len > buffer_len)
2059                 len = buffer_len;
2060         if (!len)
2061                 goto out;
2062         /* head->read_buf changes by some functions. */
2063         cp = head->read_buf;
2064         if (copy_to_user(buffer, cp, len)) {
2065                 len = -EFAULT;
2066                 goto out;
2067         }
2068         head->read_avail -= len;
2069         memmove(cp, cp + len, head->read_avail);
2070  out:
2071         mutex_unlock(&head->io_sem);
2072         return len;
2073 }
2074
2075 /**
2076  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2077  *
2078  * @file:       Pointer to "struct file".
2079  * @buffer:     Pointer to buffer to read from.
2080  * @buffer_len: Size of @buffer.
2081  *
2082  * Returns @buffer_len on success, negative value otherwise.
2083  *
2084  * Caller holds tomoyo_read_lock().
2085  */
2086 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2087                                 const int buffer_len)
2088 {
2089         struct tomoyo_io_buffer *head = file->private_data;
2090         int error = buffer_len;
2091         int avail_len = buffer_len;
2092         char *cp0 = head->write_buf;
2093
2094         if (!head->write)
2095                 return -ENOSYS;
2096         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2097                 return -EFAULT;
2098         /* Don't allow updating policies by non manager programs. */
2099         if (head->write != tomoyo_write_pid &&
2100             head->write != tomoyo_write_domain_policy &&
2101             !tomoyo_is_policy_manager())
2102                 return -EPERM;
2103         if (mutex_lock_interruptible(&head->io_sem))
2104                 return -EINTR;
2105         /* Read a line and dispatch it to the policy handler. */
2106         while (avail_len > 0) {
2107                 char c;
2108                 if (head->write_avail >= head->writebuf_size - 1) {
2109                         error = -ENOMEM;
2110                         break;
2111                 } else if (get_user(c, buffer)) {
2112                         error = -EFAULT;
2113                         break;
2114                 }
2115                 buffer++;
2116                 avail_len--;
2117                 cp0[head->write_avail++] = c;
2118                 if (c != '\n')
2119                         continue;
2120                 cp0[head->write_avail - 1] = '\0';
2121                 head->write_avail = 0;
2122                 tomoyo_normalize_line(cp0);
2123                 head->write(head);
2124         }
2125         mutex_unlock(&head->io_sem);
2126         return error;
2127 }
2128
2129 /**
2130  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2131  *
2132  * @file: Pointer to "struct file".
2133  *
2134  * Releases memory and returns 0.
2135  *
2136  * Caller looses tomoyo_read_lock().
2137  */
2138 static int tomoyo_close_control(struct file *file)
2139 {
2140         struct tomoyo_io_buffer *head = file->private_data;
2141
2142         tomoyo_read_unlock(head->reader_idx);
2143         /* Release memory used for policy I/O. */
2144         tomoyo_free(head->read_buf);
2145         head->read_buf = NULL;
2146         tomoyo_free(head->write_buf);
2147         head->write_buf = NULL;
2148         tomoyo_free(head);
2149         head = NULL;
2150         file->private_data = NULL;
2151         return 0;
2152 }
2153
2154 /**
2155  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2156  *
2157  * @inode: Pointer to "struct inode".
2158  * @file:  Pointer to "struct file".
2159  *
2160  * Returns 0 on success, negative value otherwise.
2161  */
2162 static int tomoyo_open(struct inode *inode, struct file *file)
2163 {
2164         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2165                 - ((u8 *) NULL);
2166         return tomoyo_open_control(key, file);
2167 }
2168
2169 /**
2170  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2171  *
2172  * @inode: Pointer to "struct inode".
2173  * @file:  Pointer to "struct file".
2174  *
2175  * Returns 0 on success, negative value otherwise.
2176  */
2177 static int tomoyo_release(struct inode *inode, struct file *file)
2178 {
2179         return tomoyo_close_control(file);
2180 }
2181
2182 /**
2183  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2184  *
2185  * @file:  Pointer to "struct file".
2186  * @buf:   Pointer to buffer.
2187  * @count: Size of @buf.
2188  * @ppos:  Unused.
2189  *
2190  * Returns bytes read on success, negative value otherwise.
2191  */
2192 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2193                            loff_t *ppos)
2194 {
2195         return tomoyo_read_control(file, buf, count);
2196 }
2197
2198 /**
2199  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2200  *
2201  * @file:  Pointer to "struct file".
2202  * @buf:   Pointer to buffer.
2203  * @count: Size of @buf.
2204  * @ppos:  Unused.
2205  *
2206  * Returns @count on success, negative value otherwise.
2207  */
2208 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2209                             size_t count, loff_t *ppos)
2210 {
2211         return tomoyo_write_control(file, buf, count);
2212 }
2213
2214 /*
2215  * tomoyo_operations is a "struct file_operations" which is used for handling
2216  * /sys/kernel/security/tomoyo/ interface.
2217  *
2218  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2219  * See tomoyo_io_buffer for internals.
2220  */
2221 static const struct file_operations tomoyo_operations = {
2222         .open    = tomoyo_open,
2223         .release = tomoyo_release,
2224         .read    = tomoyo_read,
2225         .write   = tomoyo_write,
2226 };
2227
2228 /**
2229  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2230  *
2231  * @name:   The name of the interface file.
2232  * @mode:   The permission of the interface file.
2233  * @parent: The parent directory.
2234  * @key:    Type of interface.
2235  *
2236  * Returns nothing.
2237  */
2238 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2239                                        struct dentry *parent, const u8 key)
2240 {
2241         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2242                                &tomoyo_operations);
2243 }
2244
2245 /**
2246  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2247  *
2248  * Returns 0.
2249  */
2250 static int __init tomoyo_initerface_init(void)
2251 {
2252         struct dentry *tomoyo_dir;
2253
2254         /* Don't create securityfs entries unless registered. */
2255         if (current_cred()->security != &tomoyo_kernel_domain)
2256                 return 0;
2257
2258         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2259         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2260                             TOMOYO_DOMAINPOLICY);
2261         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2262                             TOMOYO_EXCEPTIONPOLICY);
2263         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2264                             TOMOYO_SELFDOMAIN);
2265         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2266                             TOMOYO_DOMAIN_STATUS);
2267         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2268                             TOMOYO_PROCESS_STATUS);
2269         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2270                             TOMOYO_MEMINFO);
2271         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2272                             TOMOYO_PROFILE);
2273         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2274                             TOMOYO_MANAGER);
2275         tomoyo_create_entry("version",          0400, tomoyo_dir,
2276                             TOMOYO_VERSION);
2277         return 0;
2278 }
2279
2280 fs_initcall(tomoyo_initerface_init);