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/slab.h>
  14 #include <linux/security.h>
  15 #include <linux/hardirq.h>
  16 #include "common.h"
  17
  18 /* Lock for protecting policy. */
  19 DEFINE_MUTEX(tomoyo_policy_lock);
  20
  21 /* Has loading policy done? */
  22 bool tomoyo_policy_loaded;
  23
  24 /* String table for functionality that takes 4 modes. */
  25 static const char *tomoyo_mode_4[4] = {
  26         "disabled", "learning", "permissive", "enforcing"
  27 };
  28 /* String table for functionality that takes 2 modes. */
  29 static const char *tomoyo_mode_2[4] = {
  30         "disabled", "enabled", "enabled", "enabled"
  31 };
  32
  33 /*
  34  * tomoyo_control_array is a static data which contains
  35  *
  36  *  (1) functionality name used by /sys/kernel/security/tomoyo/profile .
  37  *  (2) initial values for "struct tomoyo_profile".
  38  *  (3) max values for "struct tomoyo_profile".
  39  */
  40 static struct {
  41         const char *keyword;
  42         unsigned int current_value;
  43         const unsigned int max_value;
  44 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
  45         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
  46         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
  47         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
  48 };
  49
  50 /*
  51  * tomoyo_profile is a structure which is used for holding the mode of access
  52  * controls. TOMOYO has 4 modes: disabled, learning, permissive, enforcing.
  53  * An administrator can define up to 256 profiles.
  54  * The ->profile of "struct tomoyo_domain_info" is used for remembering
  55  * the profile's number (0 - 255) assigned to that domain.
  56  */
  57 static struct tomoyo_profile {
  58         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
  59         const struct tomoyo_path_info *comment;
  60 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
  61
  62 /* Permit policy management by non-root user? */
  63 static bool tomoyo_manage_by_non_root;
  64
  65 /* Utility functions. */
  66
  67 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
  68 static int tomoyo_open_control(const u8 type, struct file *file);
  69 /* Close /sys/kernel/security/tomoyo/ interface. */
  70 static int tomoyo_close_control(struct file *file);
  71 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
  72 static int tomoyo_read_control(struct file *file, char __user *buffer,
  73                                const int buffer_len);
  74 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
  75 static int tomoyo_write_control(struct file *file, const char __user *buffer,
  76                                 const int buffer_len);
  77
  78 /**
  79  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
  80  *
  81  * @str: Pointer to the string.
  82  *
  83  * Returns true if @str is a \ooo style octal value, false otherwise.
  84  *
  85  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
  86  * This function verifies that \ooo is in valid range.
  87  */
  88 static inline bool tomoyo_is_byte_range(const char *str)
  89 {
  90         return *str >= '0' && *str++ <= '3' &&
  91                 *str >= '0' && *str++ <= '7' &&
  92                 *str >= '0' && *str <= '7';
  93 }
  94
  95 /**
  96  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
  97  *
  98  * @c: The character to check.
  99  *
 100  * Returns true if @c is an alphabet character, false otherwise.
 101  */
 102 static inline bool tomoyo_is_alphabet_char(const char c)
 103 {
 104         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 105 }
 106
 107 /**
 108  * tomoyo_make_byte - Make byte value from three octal characters.
 109  *
 110  * @c1: The first character.
 111  * @c2: The second character.
 112  * @c3: The third character.
 113  *
 114  * Returns byte value.
 115  */
 116 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 117 {
 118         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 119 }
 120
 121 /**
 122  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 123  *
 124  * @src:  Pointer to pointer to the string.
 125  * @find: Pointer to the keyword.
 126  *
 127  * Returns true if @src starts with @find, false otherwise.
 128  *
 129  * The @src is updated to point the first character after the @find
 130  * if @src starts with @find.
 131  */
 132 static bool tomoyo_str_starts(char **src, const char *find)
 133 {
 134         const int len = strlen(find);
 135         char *tmp = *src;
 136
 137         if (strncmp(tmp, find, len))
 138                 return false;
 139         tmp += len;
 140         *src = tmp;
 141         return true;
 142 }
 143
 144 /**
 145  * tomoyo_normalize_line - Format string.
 146  *
 147  * @buffer: The line to normalize.
 148  *
 149  * Leading and trailing whitespaces are removed.
 150  * Multiple whitespaces are packed into single space.
 151  *
 152  * Returns nothing.
 153  */
 154 static void tomoyo_normalize_line(unsigned char *buffer)
 155 {
 156         unsigned char *sp = buffer;
 157         unsigned char *dp = buffer;
 158         bool first = true;
 159
 160         while (tomoyo_is_invalid(*sp))
 161                 sp++;
 162         while (*sp) {
 163                 if (!first)
 164                         *dp++ = ' ';
 165                 first = false;
 166                 while (tomoyo_is_valid(*sp))
 167                         *dp++ = *sp++;
 168                 while (tomoyo_is_invalid(*sp))
 169                         sp++;
 170         }
 171         *dp = '\0';
 172 }
 173
 174 /**
 175  * tomoyo_is_correct_path - Validate a pathname.
 176  * @filename:     The pathname to check.
 177  * @start_type:   Should the pathname start with '/'?
 178  *                1 = must / -1 = must not / 0 = don't care
 179  * @pattern_type: Can the pathname contain a wildcard?
 180  *                1 = must / -1 = must not / 0 = don't care
 181  * @end_type:     Should the pathname end with '/'?
 182  *                1 = must / -1 = must not / 0 = don't care
 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 {
 190         const char *const start = filename;
 191         bool in_repetition = false;
 192         bool contains_pattern = false;
 193         unsigned char c;
 194         unsigned char d;
 195         unsigned char e;
 196
 197         if (!filename)
 198                 goto out;
 199         c = *filename;
 200         if (start_type == 1) { /* Must start with '/' */
 201                 if (c != '/')
 202                         goto out;
 203         } else if (start_type == -1) { /* Must not start with '/' */
 204                 if (c == '/')
 205                         goto out;
 206         }
 207         if (c)
 208                 c = *(filename + strlen(filename) - 1);
 209         if (end_type == 1) { /* Must end with '/' */
 210                 if (c != '/')
 211                         goto out;
 212         } else if (end_type == -1) { /* Must not end with '/' */
 213                 if (c == '/')
 214                         goto out;
 215         }
 216         while (1) {
 217                 c = *filename++;
 218                 if (!c)
 219                         break;
 220                 if (c == '\\') {
 221                         c = *filename++;
 222                         switch (c) {
 223                         case '\\':  /* "\\" */
 224                                 continue;
 225                         case '$':   /* "\$" */
 226                         case '+':   /* "\+" */
 227                         case '?':   /* "\?" */
 228                         case '*':   /* "\*" */
 229                         case '@':   /* "\@" */
 230                         case 'x':   /* "\x" */
 231                         case 'X':   /* "\X" */
 232                         case 'a':   /* "\a" */
 233                         case 'A':   /* "\A" */
 234                         case '-':   /* "\-" */
 235                                 if (pattern_type == -1)
 236                                         break; /* Must not contain pattern */
 237                                 contains_pattern = true;
 238                                 continue;
 239                         case '{':   /* "/\{" */
 240                                 if (filename - 3 < start ||
 241                                     *(filename - 3) != '/')
 242                                         break;
 243                                 if (pattern_type == -1)
 244                                         break; /* Must not contain pattern */
 245                                 contains_pattern = true;
 246                                 in_repetition = true;
 247                                 continue;
 248                         case '}':   /* "\}/" */
 249                                 if (*filename != '/')
 250                                         break;
 251                                 if (!in_repetition)
 252                                         break;
 253                                 in_repetition = false;
 254                                 continue;
 255                         case '0':   /* "\ooo" */
 256                         case '1':
 257                         case '2':
 258                         case '3':
 259                                 d = *filename++;
 260                                 if (d < '0' || d > '7')
 261                                         break;
 262                                 e = *filename++;
 263                                 if (e < '0' || e > '7')
 264                                         break;
 265                                 c = tomoyo_make_byte(c, d, e);
 266                                 if (tomoyo_is_invalid(c))
 267                                         continue; /* pattern is not \000 */
 268                         }
 269                         goto out;
 270                 } else if (in_repetition && c == '/') {
 271                         goto out;
 272                 } else if (tomoyo_is_invalid(c)) {
 273                         goto out;
 274                 }
 275         }
 276         if (pattern_type == 1) { /* Must contain pattern */
 277                 if (!contains_pattern)
 278                         goto out;
 279         }
 280         if (in_repetition)
 281                 goto out;
 282         return true;
 283  out:
 284         return false;
 285 }
 286
 287 /**
 288  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 289  * @domainname:   The domainname to check.
 290  *
 291  * Returns true if @domainname follows the naming rules, false otherwise.
 292  */
 293 bool tomoyo_is_correct_domain(const unsigned char *domainname)
 294 {
 295         unsigned char c;
 296         unsigned char d;
 297         unsigned char e;
 298
 299         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 300                                    TOMOYO_ROOT_NAME_LEN))
 301                 goto out;
 302         domainname += TOMOYO_ROOT_NAME_LEN;
 303         if (!*domainname)
 304                 return true;
 305         do {
 306                 if (*domainname++ != ' ')
 307                         goto out;
 308                 if (*domainname++ != '/')
 309                         goto out;
 310                 while ((c = *domainname) != '\0' && c != ' ') {
 311                         domainname++;
 312                         if (c == '\\') {
 313                                 c = *domainname++;
 314                                 switch ((c)) {
 315                                 case '\\':  /* "\\" */
 316                                         continue;
 317                                 case '0':   /* "\ooo" */
 318                                 case '1':
 319                                 case '2':
 320                                 case '3':
 321                                         d = *domainname++;
 322                                         if (d < '0' || d > '7')
 323                                                 break;
 324                                         e = *domainname++;
 325                                         if (e < '0' || e > '7')
 326                                                 break;
 327                                         c = tomoyo_make_byte(c, d, e);
 328                                         if (tomoyo_is_invalid(c))
 329                                                 /* pattern is not \000 */
 330                                                 continue;
 331                                 }
 332                                 goto out;
 333                         } else if (tomoyo_is_invalid(c)) {
 334                                 goto out;
 335                         }
 336                 }
 337         } while (*domainname);
 338         return true;
 339  out:
 340         return false;
 341 }
 342
 343 /**
 344  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 345  *
 346  * @buffer: The token to check.
 347  *
 348  * Returns true if @buffer possibly be a domainname, false otherwise.
 349  */
 350 bool tomoyo_is_domain_def(const unsigned char *buffer)
 351 {
 352         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 353 }
 354
 355 /**
 356  * tomoyo_find_domain - Find a domain by the given name.
 357  *
 358  * @domainname: The domainname to find.
 359  *
 360  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 361  *
 362  * Caller holds tomoyo_read_lock().
 363  */
 364 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 365 {
 366         struct tomoyo_domain_info *domain;
 367         struct tomoyo_path_info name;
 368
 369         name.name = domainname;
 370         tomoyo_fill_path_info(&name);
 371         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 372                 if (!domain->is_deleted &&
 373                     !tomoyo_pathcmp(&name, domain->domainname))
 374                         return domain;
 375         }
 376         return NULL;
 377 }
 378
 379 /**
 380  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 381  *
 382  * @filename: The string to evaluate.
 383  *
 384  * Returns the initial length without a pattern in @filename.
 385  */
 386 static int tomoyo_const_part_length(const char *filename)
 387 {
 388         char c;
 389         int len = 0;
 390
 391         if (!filename)
 392                 return 0;
 393         while ((c = *filename++) != '\0') {
 394                 if (c != '\\') {
 395                         len++;
 396                         continue;
 397                 }
 398                 c = *filename++;
 399                 switch (c) {
 400                 case '\\':  /* "\\" */
 401                         len += 2;
 402                         continue;
 403                 case '0':   /* "\ooo" */
 404                 case '1':
 405                 case '2':
 406                 case '3':
 407                         c = *filename++;
 408                         if (c < '0' || c > '7')
 409                                 break;
 410                         c = *filename++;
 411                         if (c < '0' || c > '7')
 412                                 break;
 413                         len += 4;
 414                         continue;
 415                 }
 416                 break;
 417         }
 418         return len;
 419 }
 420
 421 /**
 422  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 423  *
 424  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 425  *
 426  * The caller sets "struct tomoyo_path_info"->name.
 427  */
 428 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 429 {
 430         const char *name = ptr->name;
 431         const int len = strlen(name);
 432
 433         ptr->const_len = tomoyo_const_part_length(name);
 434         ptr->is_dir = len && (name[len - 1] == '/');
 435         ptr->is_patterned = (ptr->const_len < len);
 436         ptr->hash = full_name_hash(name, len);
 437 }
 438
 439 /**
 440  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
 441  * and "\-" pattern.
 442  *
 443  * @filename:     The start of string to check.
 444  * @filename_end: The end of string to check.
 445  * @pattern:      The start of pattern to compare.
 446  * @pattern_end:  The end of pattern to compare.
 447  *
 448  * Returns true if @filename matches @pattern, false otherwise.
 449  */
 450 static bool tomoyo_file_matches_pattern2(const char *filename,
 451                                          const char *filename_end,
 452                                          const char *pattern,
 453                                          const char *pattern_end)
 454 {
 455         while (filename < filename_end && pattern < pattern_end) {
 456                 char c;
 457                 if (*pattern != '\\') {
 458                         if (*filename++ != *pattern++)
 459                                 return false;
 460                         continue;
 461                 }
 462                 c = *filename;
 463                 pattern++;
 464                 switch (*pattern) {
 465                         int i;
 466                         int j;
 467                 case '?':
 468                         if (c == '/') {
 469                                 return false;
 470                         } else if (c == '\\') {
 471                                 if (filename[1] == '\\')
 472                                         filename++;
 473                                 else if (tomoyo_is_byte_range(filename + 1))
 474                                         filename += 3;
 475                                 else
 476                                         return false;
 477                         }
 478                         break;
 479                 case '\\':
 480                         if (c != '\\')
 481                                 return false;
 482                         if (*++filename != '\\')
 483                                 return false;
 484                         break;
 485                 case '+':
 486                         if (!isdigit(c))
 487                                 return false;
 488                         break;
 489                 case 'x':
 490                         if (!isxdigit(c))
 491                                 return false;
 492                         break;
 493                 case 'a':
 494                         if (!tomoyo_is_alphabet_char(c))
 495                                 return false;
 496                         break;
 497                 case '0':
 498                 case '1':
 499                 case '2':
 500                 case '3':
 501                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 502                             && strncmp(filename + 1, pattern, 3) == 0) {
 503                                 filename += 3;
 504                                 pattern += 2;
 505                                 break;
 506                         }
 507                         return false; /* Not matched. */
 508                 case '*':
 509                 case '@':
 510                         for (i = 0; i <= filename_end - filename; i++) {
 511                                 if (tomoyo_file_matches_pattern2(
 512                                                     filename + i, filename_end,
 513                                                     pattern + 1, pattern_end))
 514                                         return true;
 515                                 c = filename[i];
 516                                 if (c == '.' && *pattern == '@')
 517                                         break;
 518                                 if (c != '\\')
 519                                         continue;
 520                                 if (filename[i + 1] == '\\')
 521                                         i++;
 522                                 else if (tomoyo_is_byte_range(filename + i + 1))
 523                                         i += 3;
 524                                 else
 525                                         break; /* Bad pattern. */
 526                         }
 527                         return false; /* Not matched. */
 528                 default:
 529                         j = 0;
 530                         c = *pattern;
 531                         if (c == '$') {
 532                                 while (isdigit(filename[j]))
 533                                         j++;
 534                         } else if (c == 'X') {
 535                                 while (isxdigit(filename[j]))
 536                                         j++;
 537                         } else if (c == 'A') {
 538                                 while (tomoyo_is_alphabet_char(filename[j]))
 539                                         j++;
 540                         }
 541                         for (i = 1; i <= j; i++) {
 542                                 if (tomoyo_file_matches_pattern2(
 543                                                     filename + i, filename_end,
 544                                                     pattern + 1, pattern_end))
 545                                         return true;
 546                         }
 547                         return false; /* Not matched or bad pattern. */
 548                 }
 549                 filename++;
 550                 pattern++;
 551         }
 552         while (*pattern == '\\' &&
 553                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 554                 pattern += 2;
 555         return filename == filename_end && pattern == pattern_end;
 556 }
 557
 558 /**
 559  * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
 560  *
 561  * @filename:     The start of string to check.
 562  * @filename_end: The end of string to check.
 563  * @pattern:      The start of pattern to compare.
 564  * @pattern_end:  The end of pattern to compare.
 565  *
 566  * Returns true if @filename matches @pattern, false otherwise.
 567  */
 568 static bool tomoyo_file_matches_pattern(const char *filename,
 569                                            const char *filename_end,
 570                                            const char *pattern,
 571                                            const char *pattern_end)
 572 {
 573         const char *pattern_start = pattern;
 574         bool first = true;
 575         bool result;
 576
 577         while (pattern < pattern_end - 1) {
 578                 /* Split at "\-" pattern. */
 579                 if (*pattern++ != '\\' || *pattern++ != '-')
 580                         continue;
 581                 result = tomoyo_file_matches_pattern2(filename,
 582                                                       filename_end,
 583                                                       pattern_start,
 584                                                       pattern - 2);
 585                 if (first)
 586                         result = !result;
 587                 if (result)
 588                         return false;
 589                 first = false;
 590                 pattern_start = pattern;
 591         }
 592         result = tomoyo_file_matches_pattern2(filename, filename_end,
 593                                               pattern_start, pattern_end);
 594         return first ? result : !result;
 595 }
 596
 597 /**
 598  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 599  *
 600  * @f: The start of string to check.
 601  * @p: The start of pattern to compare.
 602  *
 603  * Returns true if @f matches @p, false otherwise.
 604  */
 605 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 606 {
 607         const char *f_delimiter;
 608         const char *p_delimiter;
 609
 610         while (*f && *p) {
 611                 f_delimiter = strchr(f, '/');
 612                 if (!f_delimiter)
 613                         f_delimiter = f + strlen(f);
 614                 p_delimiter = strchr(p, '/');
 615                 if (!p_delimiter)
 616                         p_delimiter = p + strlen(p);
 617                 if (*p == '\\' && *(p + 1) == '{')
 618                         goto recursive;
 619                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 620                                                  p_delimiter))
 621                         return false;
 622                 f = f_delimiter;
 623                 if (*f)
 624                         f++;
 625                 p = p_delimiter;
 626                 if (*p)
 627                         p++;
 628         }
 629         /* Ignore trailing "\*" and "\@" in @pattern. */
 630         while (*p == '\\' &&
 631                (*(p + 1) == '*' || *(p + 1) == '@'))
 632                 p += 2;
 633         return !*f && !*p;
 634  recursive:
 635         /*
 636          * The "\{" pattern is permitted only after '/' character.
 637          * This guarantees that below "*(p - 1)" is safe.
 638          * Also, the "\}" pattern is permitted only before '/' character
 639          * so that "\{" + "\}" pair will not break the "\-" operator.
 640          */
 641         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 642             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 643                 return false; /* Bad pattern. */
 644         do {
 645                 /* Compare current component with pattern. */
 646                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 647                                                  p_delimiter - 2))
 648                         break;
 649                 /* Proceed to next component. */
 650                 f = f_delimiter;
 651                 if (!*f)
 652                         break;
 653                 f++;
 654                 /* Continue comparison. */
 655                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 656                         return true;
 657                 f_delimiter = strchr(f, '/');
 658         } while (f_delimiter);
 659         return false; /* Not matched. */
 660 }
 661
 662 /**
 663  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 664  *
 665  * @filename: The filename to check.
 666  * @pattern:  The pattern to compare.
 667  *
 668  * Returns true if matches, false otherwise.
 669  *
 670  * The following patterns are available.
 671  *   \\     \ itself.
 672  *   \ooo   Octal representation of a byte.
 673  *   \*     Zero or more repetitions of characters other than '/'.
 674  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 675  *   \?     1 byte character other than '/'.
 676  *   \$     One or more repetitions of decimal digits.
 677  *   \+     1 decimal digit.
 678  *   \X     One or more repetitions of hexadecimal digits.
 679  *   \x     1 hexadecimal digit.
 680  *   \A     One or more repetitions of alphabet characters.
 681  *   \a     1 alphabet character.
 682  *
 683  *   \-     Subtraction operator.
 684  *
 685  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 686  *               /dir/dir/dir/ ).
 687  */
 688 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 689                                  const struct tomoyo_path_info *pattern)
 690 {
 691         const char *f = filename->name;
 692         const char *p = pattern->name;
 693         const int len = pattern->const_len;
 694
 695         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 696         if (!pattern->is_patterned)
 697                 return !tomoyo_pathcmp(filename, pattern);
 698         /* Don't compare directory and non-directory. */
 699         if (filename->is_dir != pattern->is_dir)
 700                 return false;
 701         /* Compare the initial length without patterns. */
 702         if (strncmp(f, p, len))
 703                 return false;
 704         f += len;
 705         p += len;
 706         return tomoyo_path_matches_pattern2(f, p);
 707 }
 708
 709 /**
 710  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 711  *
 712  * @head: Pointer to "struct tomoyo_io_buffer".
 713  * @fmt:  The printf()'s format string, followed by parameters.
 714  *
 715  * Returns true if output was written, false otherwise.
 716  *
 717  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 718  */
 719 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 720 {
 721         va_list args;
 722         int len;
 723         int pos = head->read_avail;
 724         int size = head->readbuf_size - pos;
 725
 726         if (size <= 0)
 727                 return false;
 728         va_start(args, fmt);
 729         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 730         va_end(args);
 731         if (pos + len >= head->readbuf_size)
 732                 return false;
 733         head->read_avail += len;
 734         return true;
 735 }
 736
 737 /**
 738  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 739  *
 740  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 741  *
 742  * This function uses kzalloc(), so the caller must call kfree()
 743  * if this function didn't return NULL.
 744  */
 745 static const char *tomoyo_get_exe(void)
 746 {
 747         struct mm_struct *mm = current->mm;
 748         struct vm_area_struct *vma;
 749         const char *cp = NULL;
 750
 751         if (!mm)
 752                 return NULL;
 753         down_read(&mm->mmap_sem);
 754         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 755                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 756                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 757                         break;
 758                 }
 759         }
 760         up_read(&mm->mmap_sem);
 761         return cp;
 762 }
 763
 764 /**
 765  * tomoyo_get_msg - Get warning message.
 766  *
 767  * @is_enforce: Is it enforcing mode?
 768  *
 769  * Returns "ERROR" or "WARNING".
 770  */
 771 const char *tomoyo_get_msg(const bool is_enforce)
 772 {
 773         if (is_enforce)
 774                 return "ERROR";
 775         else
 776                 return "WARNING";
 777 }
 778
 779 /**
 780  * tomoyo_check_flags - Check mode for specified functionality.
 781  *
 782  * @domain: Pointer to "struct tomoyo_domain_info".
 783  * @index:  The functionality to check mode.
 784  *
 785  * TOMOYO checks only process context.
 786  * This code disables TOMOYO's enforcement in case the function is called from
 787  * interrupt context.
 788  */
 789 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 790                                 const u8 index)
 791 {
 792         const u8 profile = domain->profile;
 793
 794         if (WARN_ON(in_interrupt()))
 795                 return 0;
 796         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 797 #if TOMOYO_MAX_PROFILES != 256
 798                 && profile < TOMOYO_MAX_PROFILES
 799 #endif
 800                 && tomoyo_profile_ptr[profile] ?
 801                 tomoyo_profile_ptr[profile]->value[index] : 0;
 802 }
 803
 804 /**
 805  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 806  *
 807  * @domain: Pointer to "struct tomoyo_domain_info".
 808  *
 809  * Returns true if domain policy violation warning should be printed to
 810  * console.
 811  */
 812 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 813 {
 814         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 815 }
 816
 817 /**
 818  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 819  *
 820  * @domain: Pointer to "struct tomoyo_domain_info".
 821  *
 822  * Returns true if the domain is not exceeded quota, false otherwise.
 823  *
 824  * Caller holds tomoyo_read_lock().
 825  */
 826 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 827 {
 828         unsigned int count = 0;
 829         struct tomoyo_acl_info *ptr;
 830
 831         if (!domain)
 832                 return true;
 833         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 834                 switch (ptr->type) {
 835                         struct tomoyo_path_acl *acl;
 836                         u32 perm;
 837                         u8 i;
 838                 case TOMOYO_TYPE_PATH_ACL:
 839                         acl = container_of(ptr, struct tomoyo_path_acl, head);
 840                         perm = acl->perm | (((u32) acl->perm_high) << 16);
 841                         for (i = 0; i < TOMOYO_MAX_PATH_OPERATION; i++)
 842                                 if (perm & (1 << i))
 843                                         count++;
 844                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
 845                                 count -= 2;
 846                         break;
 847                 case TOMOYO_TYPE_PATH2_ACL:
 848                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
 849                                 ->perm;
 850                         for (i = 0; i < TOMOYO_MAX_PATH2_OPERATION; i++)
 851                                 if (perm & (1 << i))
 852                                         count++;
 853                         break;
 854                 }
 855         }
 856         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 857                 return true;
 858         if (!domain->quota_warned) {
 859                 domain->quota_warned = true;
 860                 printk(KERN_WARNING "TOMOYO-WARNING: "
 861                        "Domain '%s' has so many ACLs to hold. "
 862                        "Stopped learning mode.\n", domain->domainname->name);
 863         }
 864         return false;
 865 }
 866
 867 /**
 868  * tomoyo_find_or_assign_new_profile - Create a new profile.
 869  *
 870  * @profile: Profile number to create.
 871  *
 872  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 873  */
 874 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 875                                                                 int profile)
 876 {
 877         struct tomoyo_profile *ptr = NULL;
 878         int i;
 879
 880         if (profile >= TOMOYO_MAX_PROFILES)
 881                 return NULL;
 882         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 883                 return NULL;
 884         ptr = tomoyo_profile_ptr[profile];
 885         if (ptr)
 886                 goto ok;
 887         ptr = kmalloc(sizeof(*ptr), GFP_NOFS);
 888         if (!tomoyo_memory_ok(ptr)) {
 889                 kfree(ptr);
 890                 ptr = NULL;
 891                 goto ok;
 892         }
 893         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 894                 ptr->value[i] = tomoyo_control_array[i].current_value;
 895         mb(); /* Avoid out-of-order execution. */
 896         tomoyo_profile_ptr[profile] = ptr;
 897  ok:
 898         mutex_unlock(&tomoyo_policy_lock);
 899         return ptr;
 900 }
 901
 902 /**
 903  * tomoyo_write_profile - Write to profile table.
 904  *
 905  * @head: Pointer to "struct tomoyo_io_buffer".
 906  *
 907  * Returns 0 on success, negative value otherwise.
 908  */
 909 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 910 {
 911         char *data = head->write_buf;
 912         unsigned int i;
 913         unsigned int value;
 914         char *cp;
 915         struct tomoyo_profile *profile;
 916         unsigned long num;
 917
 918         cp = strchr(data, '-');
 919         if (cp)
 920                 *cp = '\0';
 921         if (strict_strtoul(data, 10, &num))
 922                 return -EINVAL;
 923         if (cp)
 924                 data = cp + 1;
 925         profile = tomoyo_find_or_assign_new_profile(num);
 926         if (!profile)
 927                 return -EINVAL;
 928         cp = strchr(data, '=');
 929         if (!cp)
 930                 return -EINVAL;
 931         *cp = '\0';
 932         if (!strcmp(data, "COMMENT")) {
 933                 const struct tomoyo_path_info *old_comment = profile->comment;
 934                 profile->comment = tomoyo_get_name(cp + 1);
 935                 tomoyo_put_name(old_comment);
 936                 return 0;
 937         }
 938         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 939                 if (strcmp(data, tomoyo_control_array[i].keyword))
 940                         continue;
 941                 if (sscanf(cp + 1, "%u", &value) != 1) {
 942                         int j;
 943                         const char **modes;
 944                         switch (i) {
 945                         case TOMOYO_VERBOSE:
 946                                 modes = tomoyo_mode_2;
 947                                 break;
 948                         default:
 949                                 modes = tomoyo_mode_4;
 950                                 break;
 951                         }
 952                         for (j = 0; j < 4; j++) {
 953                                 if (strcmp(cp + 1, modes[j]))
 954                                         continue;
 955                                 value = j;
 956                                 break;
 957                         }
 958                         if (j == 4)
 959                                 return -EINVAL;
 960                 } else if (value > tomoyo_control_array[i].max_value) {
 961                         value = tomoyo_control_array[i].max_value;
 962                 }
 963                 profile->value[i] = value;
 964                 return 0;
 965         }
 966         return -EINVAL;
 967 }
 968
 969 /**
 970  * tomoyo_read_profile - Read from profile table.
 971  *
 972  * @head: Pointer to "struct tomoyo_io_buffer".
 973  *
 974  * Returns 0.
 975  */
 976 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 977 {
 978         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 979         int step;
 980
 981         if (head->read_eof)
 982                 return 0;
 983         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 984              step++) {
 985                 const u8 index = step / total;
 986                 u8 type = step % total;
 987                 const struct tomoyo_profile *profile
 988                         = tomoyo_profile_ptr[index];
 989                 head->read_step = step;
 990                 if (!profile)
 991                         continue;
 992                 if (!type) { /* Print profile' comment tag. */
 993                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
 994                                               index, profile->comment ?
 995                                               profile->comment->name : ""))
 996                                 break;
 997                         continue;
 998                 }
 999                 type--;
1000                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1001                         const unsigned int value = profile->value[type];
1002                         const char **modes = NULL;
1003                         const char *keyword
1004                                 = tomoyo_control_array[type].keyword;
1005                         switch (tomoyo_control_array[type].max_value) {
1006                         case 3:
1007                                 modes = tomoyo_mode_4;
1008                                 break;
1009                         case 1:
1010                                 modes = tomoyo_mode_2;
1011                                 break;
1012                         }
1013                         if (modes) {
1014                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1015                                                       keyword, modes[value]))
1016                                         break;
1017                         } else {
1018                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1019                                                       keyword, value))
1020                                         break;
1021                         }
1022                 }
1023         }
1024         if (step == TOMOYO_MAX_PROFILES * total)
1025                 head->read_eof = true;
1026         return 0;
1027 }
1028
1029 /*
1030  * tomoyo_policy_manager_list is used for holding list of domainnames or
1031  * programs which are permitted to modify configuration via
1032  * /sys/kernel/security/tomoyo/ interface.
1033  *
1034  * An entry is added by
1035  *
1036  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1037  *                                        /sys/kernel/security/tomoyo/manager
1038  *  (if you want to specify by a domainname)
1039  *
1040  *  or
1041  *
1042  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1043  *  (if you want to specify by a program's location)
1044  *
1045  * and is deleted by
1046  *
1047  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1048  *                                        /sys/kernel/security/tomoyo/manager
1049  *
1050  *  or
1051  *
1052  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1053  *                                        /sys/kernel/security/tomoyo/manager
1054  *
1055  * and all entries are retrieved by
1056  *
1057  * # cat /sys/kernel/security/tomoyo/manager
1058  */
1059 LIST_HEAD(tomoyo_policy_manager_list);
1060
1061 /**
1062  * tomoyo_update_manager_entry - Add a manager entry.
1063  *
1064  * @manager:   The path to manager or the domainnamme.
1065  * @is_delete: True if it is a delete request.
1066  *
1067  * Returns 0 on success, negative value otherwise.
1068  *
1069  * Caller holds tomoyo_read_lock().
1070  */
1071 static int tomoyo_update_manager_entry(const char *manager,
1072                                        const bool is_delete)
1073 {
1074         struct tomoyo_policy_manager_entry *ptr;
1075         struct tomoyo_policy_manager_entry e = { };
1076         int error = is_delete ? -ENOENT : -ENOMEM;
1077
1078         if (tomoyo_is_domain_def(manager)) {
1079                 if (!tomoyo_is_correct_domain(manager))
1080                         return -EINVAL;
1081                 e.is_domain = true;
1082         } else {
1083                 if (!tomoyo_is_correct_path(manager, 1, -1, -1))
1084                         return -EINVAL;
1085         }
1086         e.manager = tomoyo_get_name(manager);
1087         if (!e.manager)
1088                 return -ENOMEM;
1089         if (mutex_lock_interruptible(&tomoyo_policy_lock))
1090                 goto out;
1091         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1092                 if (ptr->manager != e.manager)
1093                         continue;
1094                 ptr->is_deleted = is_delete;
1095                 error = 0;
1096                 break;
1097         }
1098         if (!is_delete && error) {
1099                 struct tomoyo_policy_manager_entry *entry =
1100                         tomoyo_commit_ok(&e, sizeof(e));
1101                 if (entry) {
1102                         list_add_tail_rcu(&entry->list,
1103                                           &tomoyo_policy_manager_list);
1104                         error = 0;
1105                 }
1106         }
1107         mutex_unlock(&tomoyo_policy_lock);
1108  out:
1109         tomoyo_put_name(e.manager);
1110         return error;
1111 }
1112
1113 /**
1114  * tomoyo_write_manager_policy - Write manager policy.
1115  *
1116  * @head: Pointer to "struct tomoyo_io_buffer".
1117  *
1118  * Returns 0 on success, negative value otherwise.
1119  *
1120  * Caller holds tomoyo_read_lock().
1121  */
1122 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1123 {
1124         char *data = head->write_buf;
1125         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1126
1127         if (!strcmp(data, "manage_by_non_root")) {
1128                 tomoyo_manage_by_non_root = !is_delete;
1129                 return 0;
1130         }
1131         return tomoyo_update_manager_entry(data, is_delete);
1132 }
1133
1134 /**
1135  * tomoyo_read_manager_policy - Read manager policy.
1136  *
1137  * @head: Pointer to "struct tomoyo_io_buffer".
1138  *
1139  * Returns 0.
1140  *
1141  * Caller holds tomoyo_read_lock().
1142  */
1143 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1144 {
1145         struct list_head *pos;
1146         bool done = true;
1147
1148         if (head->read_eof)
1149                 return 0;
1150         list_for_each_cookie(pos, head->read_var2,
1151                              &tomoyo_policy_manager_list) {
1152                 struct tomoyo_policy_manager_entry *ptr;
1153                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1154                                  list);
1155                 if (ptr->is_deleted)
1156                         continue;
1157                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1158                 if (!done)
1159                         break;
1160         }
1161         head->read_eof = done;
1162         return 0;
1163 }
1164
1165 /**
1166  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1167  *
1168  * Returns true if the current process is permitted to modify policy
1169  * via /sys/kernel/security/tomoyo/ interface.
1170  *
1171  * Caller holds tomoyo_read_lock().
1172  */
1173 static bool tomoyo_is_policy_manager(void)
1174 {
1175         struct tomoyo_policy_manager_entry *ptr;
1176         const char *exe;
1177         const struct task_struct *task = current;
1178         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1179         bool found = false;
1180
1181         if (!tomoyo_policy_loaded)
1182                 return true;
1183         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1184                 return false;
1185         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1186                 if (!ptr->is_deleted && ptr->is_domain
1187                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1188                         found = true;
1189                         break;
1190                 }
1191         }
1192         if (found)
1193                 return true;
1194         exe = tomoyo_get_exe();
1195         if (!exe)
1196                 return false;
1197         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1198                 if (!ptr->is_deleted && !ptr->is_domain
1199                     && !strcmp(exe, ptr->manager->name)) {
1200                         found = true;
1201                         break;
1202                 }
1203         }
1204         if (!found) { /* Reduce error messages. */
1205                 static pid_t last_pid;
1206                 const pid_t pid = current->pid;
1207                 if (last_pid != pid) {
1208                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1209                                "update policies.\n", domainname->name, exe);
1210                         last_pid = pid;
1211                 }
1212         }
1213         kfree(exe);
1214         return found;
1215 }
1216
1217 /**
1218  * tomoyo_is_select_one - Parse select command.
1219  *
1220  * @head: Pointer to "struct tomoyo_io_buffer".
1221  * @data: String to parse.
1222  *
1223  * Returns true on success, false otherwise.
1224  *
1225  * Caller holds tomoyo_read_lock().
1226  */
1227 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1228                                  const char *data)
1229 {
1230         unsigned int pid;
1231         struct tomoyo_domain_info *domain = NULL;
1232
1233         if (sscanf(data, "pid=%u", &pid) == 1) {
1234                 struct task_struct *p;
1235                 rcu_read_lock();
1236                 read_lock(&tasklist_lock);
1237                 p = find_task_by_vpid(pid);
1238                 if (p)
1239                         domain = tomoyo_real_domain(p);
1240                 read_unlock(&tasklist_lock);
1241                 rcu_read_unlock();
1242         } else if (!strncmp(data, "domain=", 7)) {
1243                 if (tomoyo_is_domain_def(data + 7))
1244                         domain = tomoyo_find_domain(data + 7);
1245         } else
1246                 return false;
1247         head->write_var1 = domain;
1248         /* Accessing read_buf is safe because head->io_sem is held. */
1249         if (!head->read_buf)
1250                 return true; /* Do nothing if open(O_WRONLY). */
1251         head->read_avail = 0;
1252         tomoyo_io_printf(head, "# select %s\n", data);
1253         head->read_single_domain = true;
1254         head->read_eof = !domain;
1255         if (domain) {
1256                 struct tomoyo_domain_info *d;
1257                 head->read_var1 = NULL;
1258                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1259                         if (d == domain)
1260                                 break;
1261                         head->read_var1 = &d->list;
1262                 }
1263                 head->read_var2 = NULL;
1264                 head->read_bit = 0;
1265                 head->read_step = 0;
1266                 if (domain->is_deleted)
1267                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1268         }
1269         return true;
1270 }
1271
1272 /**
1273  * tomoyo_delete_domain - Delete a domain.
1274  *
1275  * @domainname: The name of domain.
1276  *
1277  * Returns 0.
1278  *
1279  * Caller holds tomoyo_read_lock().
1280  */
1281 static int tomoyo_delete_domain(char *domainname)
1282 {
1283         struct tomoyo_domain_info *domain;
1284         struct tomoyo_path_info name;
1285
1286         name.name = domainname;
1287         tomoyo_fill_path_info(&name);
1288         if (mutex_lock_interruptible(&tomoyo_policy_lock))
1289                 return 0;
1290         /* Is there an active domain? */
1291         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1292                 /* Never delete tomoyo_kernel_domain */
1293                 if (domain == &tomoyo_kernel_domain)
1294                         continue;
1295                 if (domain->is_deleted ||
1296                     tomoyo_pathcmp(domain->domainname, &name))
1297                         continue;
1298                 domain->is_deleted = true;
1299                 break;
1300         }
1301         mutex_unlock(&tomoyo_policy_lock);
1302         return 0;
1303 }
1304
1305 /**
1306  * tomoyo_write_domain_policy - Write domain policy.
1307  *
1308  * @head: Pointer to "struct tomoyo_io_buffer".
1309  *
1310  * Returns 0 on success, negative value otherwise.
1311  *
1312  * Caller holds tomoyo_read_lock().
1313  */
1314 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1315 {
1316         char *data = head->write_buf;
1317         struct tomoyo_domain_info *domain = head->write_var1;
1318         bool is_delete = false;
1319         bool is_select = false;
1320         unsigned int profile;
1321
1322         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1323                 is_delete = true;
1324         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1325                 is_select = true;
1326         if (is_select && tomoyo_is_select_one(head, data))
1327                 return 0;
1328         /* Don't allow updating policies by non manager programs. */
1329         if (!tomoyo_is_policy_manager())
1330                 return -EPERM;
1331         if (tomoyo_is_domain_def(data)) {
1332                 domain = NULL;
1333                 if (is_delete)
1334                         tomoyo_delete_domain(data);
1335                 else if (is_select)
1336                         domain = tomoyo_find_domain(data);
1337                 else
1338                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1339                 head->write_var1 = domain;
1340                 return 0;
1341         }
1342         if (!domain)
1343                 return -EINVAL;
1344
1345         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1346             && profile < TOMOYO_MAX_PROFILES) {
1347                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1348                         domain->profile = (u8) profile;
1349                 return 0;
1350         }
1351         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1352                 domain->ignore_global_allow_read = !is_delete;
1353                 return 0;
1354         }
1355         return tomoyo_write_file_policy(data, domain, is_delete);
1356 }
1357
1358 /**
1359  * tomoyo_print_path_acl - Print a single path ACL entry.
1360  *
1361  * @head: Pointer to "struct tomoyo_io_buffer".
1362  * @ptr:  Pointer to "struct tomoyo_path_acl".
1363  *
1364  * Returns true on success, false otherwise.
1365  */
1366 static bool tomoyo_print_path_acl(struct tomoyo_io_buffer *head,
1367                                   struct tomoyo_path_acl *ptr)
1368 {
1369         int pos;
1370         u8 bit;
1371         const char *filename;
1372         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1373
1374         filename = ptr->filename->name;
1375         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
1376                 const char *msg;
1377                 if (!(perm & (1 << bit)))
1378                         continue;
1379                 /* Print "read/write" instead of "read" and "write". */
1380                 if ((bit == TOMOYO_TYPE_READ || bit == TOMOYO_TYPE_WRITE)
1381                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
1382                         continue;
1383                 msg = tomoyo_path2keyword(bit);
1384                 pos = head->read_avail;
1385                 if (!tomoyo_io_printf(head, "allow_%s %s\n", msg, filename))
1386                         goto out;
1387         }
1388         head->read_bit = 0;
1389         return true;
1390  out:
1391         head->read_bit = bit;
1392         head->read_avail = pos;
1393         return false;
1394 }
1395
1396 /**
1397  * tomoyo_print_path2_acl - Print a double path ACL entry.
1398  *
1399  * @head: Pointer to "struct tomoyo_io_buffer".
1400  * @ptr:  Pointer to "struct tomoyo_path2_acl".
1401  *
1402  * Returns true on success, false otherwise.
1403  */
1404 static bool tomoyo_print_path2_acl(struct tomoyo_io_buffer *head,
1405                                    struct tomoyo_path2_acl *ptr)
1406 {
1407         int pos;
1408         const char *filename1;
1409         const char *filename2;
1410         const u8 perm = ptr->perm;
1411         u8 bit;
1412
1413         filename1 = ptr->filename1->name;
1414         filename2 = ptr->filename2->name;
1415         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) {
1416                 const char *msg;
1417                 if (!(perm & (1 << bit)))
1418                         continue;
1419                 msg = tomoyo_path22keyword(bit);
1420                 pos = head->read_avail;
1421                 if (!tomoyo_io_printf(head, "allow_%s %s %s\n", msg,
1422                                       filename1, filename2))
1423                         goto out;
1424         }
1425         head->read_bit = 0;
1426         return true;
1427  out:
1428         head->read_bit = bit;
1429         head->read_avail = pos;
1430         return false;
1431 }
1432
1433 /**
1434  * tomoyo_print_entry - Print an ACL entry.
1435  *
1436  * @head: Pointer to "struct tomoyo_io_buffer".
1437  * @ptr:  Pointer to an ACL entry.
1438  *
1439  * Returns true on success, false otherwise.
1440  */
1441 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1442                                struct tomoyo_acl_info *ptr)
1443 {
1444         const u8 acl_type = ptr->type;
1445
1446         if (acl_type == TOMOYO_TYPE_PATH_ACL) {
1447                 struct tomoyo_path_acl *acl
1448                         = container_of(ptr, struct tomoyo_path_acl, head);
1449                 return tomoyo_print_path_acl(head, acl);
1450         }
1451         if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
1452                 struct tomoyo_path2_acl *acl
1453                         = container_of(ptr, struct tomoyo_path2_acl, head);
1454                 return tomoyo_print_path2_acl(head, acl);
1455         }
1456         BUG(); /* This must not happen. */
1457         return false;
1458 }
1459
1460 /**
1461  * tomoyo_read_domain_policy - Read domain policy.
1462  *
1463  * @head: Pointer to "struct tomoyo_io_buffer".
1464  *
1465  * Returns 0.
1466  *
1467  * Caller holds tomoyo_read_lock().
1468  */
1469 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1470 {
1471         struct list_head *dpos;
1472         struct list_head *apos;
1473         bool done = true;
1474
1475         if (head->read_eof)
1476                 return 0;
1477         if (head->read_step == 0)
1478                 head->read_step = 1;
1479         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1480                 struct tomoyo_domain_info *domain;
1481                 const char *quota_exceeded = "";
1482                 const char *transition_failed = "";
1483                 const char *ignore_global_allow_read = "";
1484                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1485                 if (head->read_step != 1)
1486                         goto acl_loop;
1487                 if (domain->is_deleted && !head->read_single_domain)
1488                         continue;
1489                 /* Print domainname and flags. */
1490                 if (domain->quota_warned)
1491                         quota_exceeded = "quota_exceeded\n";
1492                 if (domain->transition_failed)
1493                         transition_failed = "transition_failed\n";
1494                 if (domain->ignore_global_allow_read)
1495                         ignore_global_allow_read
1496                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1497                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1498                                         "%u\n%s%s%s\n",
1499                                         domain->domainname->name,
1500                                         domain->profile, quota_exceeded,
1501                                         transition_failed,
1502                                         ignore_global_allow_read);
1503                 if (!done)
1504                         break;
1505                 head->read_step = 2;
1506 acl_loop:
1507                 if (head->read_step == 3)
1508                         goto tail_mark;
1509                 /* Print ACL entries in the domain. */
1510                 list_for_each_cookie(apos, head->read_var2,
1511                                      &domain->acl_info_list) {
1512                         struct tomoyo_acl_info *ptr
1513                                 = list_entry(apos, struct tomoyo_acl_info,
1514                                              list);
1515                         done = tomoyo_print_entry(head, ptr);
1516                         if (!done)
1517                                 break;
1518                 }
1519                 if (!done)
1520                         break;
1521                 head->read_step = 3;
1522 tail_mark:
1523                 done = tomoyo_io_printf(head, "\n");
1524                 if (!done)
1525                         break;
1526                 head->read_step = 1;
1527                 if (head->read_single_domain)
1528                         break;
1529         }
1530         head->read_eof = done;
1531         return 0;
1532 }
1533
1534 /**
1535  * tomoyo_write_domain_profile - Assign profile for specified domain.
1536  *
1537  * @head: Pointer to "struct tomoyo_io_buffer".
1538  *
1539  * Returns 0 on success, -EINVAL otherwise.
1540  *
1541  * This is equivalent to doing
1542  *
1543  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1544  *     /usr/lib/ccs/loadpolicy -d
1545  *
1546  * Caller holds tomoyo_read_lock().
1547  */
1548 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1549 {
1550         char *data = head->write_buf;
1551         char *cp = strchr(data, ' ');
1552         struct tomoyo_domain_info *domain;
1553         unsigned long profile;
1554
1555         if (!cp)
1556                 return -EINVAL;
1557         *cp = '\0';
1558         domain = tomoyo_find_domain(cp + 1);
1559         if (strict_strtoul(data, 10, &profile))
1560                 return -EINVAL;
1561         if (domain && profile < TOMOYO_MAX_PROFILES
1562             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1563                 domain->profile = (u8) profile;
1564         return 0;
1565 }
1566
1567 /**
1568  * tomoyo_read_domain_profile - Read only domainname and profile.
1569  *
1570  * @head: Pointer to "struct tomoyo_io_buffer".
1571  *
1572  * Returns list of profile number and domainname pairs.
1573  *
1574  * This is equivalent to doing
1575  *
1576  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1577  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1578  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1579  *     print $2 " " domainname; domainname = ""; } } ; '
1580  *
1581  * Caller holds tomoyo_read_lock().
1582  */
1583 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1584 {
1585         struct list_head *pos;
1586         bool done = true;
1587
1588         if (head->read_eof)
1589                 return 0;
1590         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1591                 struct tomoyo_domain_info *domain;
1592                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1593                 if (domain->is_deleted)
1594                         continue;
1595                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1596                                         domain->domainname->name);
1597                 if (!done)
1598                         break;
1599         }
1600         head->read_eof = done;
1601         return 0;
1602 }
1603
1604 /**
1605  * tomoyo_write_pid: Specify PID to obtain domainname.
1606  *
1607  * @head: Pointer to "struct tomoyo_io_buffer".
1608  *
1609  * Returns 0.
1610  */
1611 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1612 {
1613         unsigned long pid;
1614         /* No error check. */
1615         strict_strtoul(head->write_buf, 10, &pid);
1616         head->read_step = (int) pid;
1617         head->read_eof = false;
1618         return 0;
1619 }
1620
1621 /**
1622  * tomoyo_read_pid - Get domainname of the specified PID.
1623  *
1624  * @head: Pointer to "struct tomoyo_io_buffer".
1625  *
1626  * Returns the domainname which the specified PID is in on success,
1627  * empty string otherwise.
1628  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1629  * using read()/write() interface rather than sysctl() interface.
1630  */
1631 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1632 {
1633         if (head->read_avail == 0 && !head->read_eof) {
1634                 const int pid = head->read_step;
1635                 struct task_struct *p;
1636                 struct tomoyo_domain_info *domain = NULL;
1637                 rcu_read_lock();
1638                 read_lock(&tasklist_lock);
1639                 p = find_task_by_vpid(pid);
1640                 if (p)
1641                         domain = tomoyo_real_domain(p);
1642                 read_unlock(&tasklist_lock);
1643                 rcu_read_unlock();
1644                 if (domain)
1645                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1646                                          domain->domainname->name);
1647                 head->read_eof = true;
1648         }
1649         return 0;
1650 }
1651
1652 /**
1653  * tomoyo_write_exception_policy - Write exception policy.
1654  *
1655  * @head: Pointer to "struct tomoyo_io_buffer".
1656  *
1657  * Returns 0 on success, negative value otherwise.
1658  *
1659  * Caller holds tomoyo_read_lock().
1660  */
1661 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1662 {
1663         char *data = head->write_buf;
1664         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1665
1666         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1667                 return tomoyo_write_domain_keeper_policy(data, false,
1668                                                          is_delete);
1669         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1670                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1671         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1672                 return tomoyo_write_domain_initializer_policy(data, false,
1673                                                               is_delete);
1674         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1675                 return tomoyo_write_domain_initializer_policy(data, true,
1676                                                               is_delete);
1677         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1678                 return tomoyo_write_alias_policy(data, is_delete);
1679         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1680                 return tomoyo_write_globally_readable_policy(data, is_delete);
1681         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1682                 return tomoyo_write_pattern_policy(data, is_delete);
1683         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1684                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1685         return -EINVAL;
1686 }
1687
1688 /**
1689  * tomoyo_read_exception_policy - Read exception policy.
1690  *
1691  * @head: Pointer to "struct tomoyo_io_buffer".
1692  *
1693  * Returns 0 on success, -EINVAL otherwise.
1694  *
1695  * Caller holds tomoyo_read_lock().
1696  */
1697 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1698 {
1699         if (!head->read_eof) {
1700                 switch (head->read_step) {
1701                 case 0:
1702                         head->read_var2 = NULL;
1703                         head->read_step = 1;
1704                 case 1:
1705                         if (!tomoyo_read_domain_keeper_policy(head))
1706                                 break;
1707                         head->read_var2 = NULL;
1708                         head->read_step = 2;
1709                 case 2:
1710                         if (!tomoyo_read_globally_readable_policy(head))
1711                                 break;
1712                         head->read_var2 = NULL;
1713                         head->read_step = 3;
1714                 case 3:
1715                         head->read_var2 = NULL;
1716                         head->read_step = 4;
1717                 case 4:
1718                         if (!tomoyo_read_domain_initializer_policy(head))
1719                                 break;
1720                         head->read_var2 = NULL;
1721                         head->read_step = 5;
1722                 case 5:
1723                         if (!tomoyo_read_alias_policy(head))
1724                                 break;
1725                         head->read_var2 = NULL;
1726                         head->read_step = 6;
1727                 case 6:
1728                         head->read_var2 = NULL;
1729                         head->read_step = 7;
1730                 case 7:
1731                         if (!tomoyo_read_file_pattern(head))
1732                                 break;
1733                         head->read_var2 = NULL;
1734                         head->read_step = 8;
1735                 case 8:
1736                         if (!tomoyo_read_no_rewrite_policy(head))
1737                                 break;
1738                         head->read_var2 = NULL;
1739                         head->read_step = 9;
1740                 case 9:
1741                         head->read_eof = true;
1742                         break;
1743                 default:
1744                         return -EINVAL;
1745                 }
1746         }
1747         return 0;
1748 }
1749
1750 /* path to policy loader */
1751 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1752
1753 /**
1754  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1755  *
1756  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1757  */
1758 static bool tomoyo_policy_loader_exists(void)
1759 {
1760         /*
1761          * Don't activate MAC if the policy loader doesn't exist.
1762          * If the initrd includes /sbin/init but real-root-dev has not
1763          * mounted on / yet, activating MAC will block the system since
1764          * policies are not loaded yet.
1765          * Thus, let do_execve() call this function everytime.
1766          */
1767         struct path path;
1768
1769         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1770                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1771                        "since %s doesn't exist.\n", tomoyo_loader);
1772                 return false;
1773         }
1774         path_put(&path);
1775         return true;
1776 }
1777
1778 /**
1779  * tomoyo_load_policy - Run external policy loader to load policy.
1780  *
1781  * @filename: The program about to start.
1782  *
1783  * This function checks whether @filename is /sbin/init , and if so
1784  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1785  * and then continues invocation of /sbin/init.
1786  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1787  * writes to /sys/kernel/security/tomoyo/ interfaces.
1788  *
1789  * Returns nothing.
1790  */
1791 void tomoyo_load_policy(const char *filename)
1792 {
1793         char *argv[2];
1794         char *envp[3];
1795
1796         if (tomoyo_policy_loaded)
1797                 return;
1798         /*
1799          * Check filename is /sbin/init or /sbin/tomoyo-start.
1800          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1801          * be passed.
1802          * You can create /sbin/tomoyo-start by
1803          * "ln -s /bin/true /sbin/tomoyo-start".
1804          */
1805         if (strcmp(filename, "/sbin/init") &&
1806             strcmp(filename, "/sbin/tomoyo-start"))
1807                 return;
1808         if (!tomoyo_policy_loader_exists())
1809                 return;
1810
1811         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1812                tomoyo_loader);
1813         argv[0] = (char *) tomoyo_loader;
1814         argv[1] = NULL;
1815         envp[0] = "HOME=/";
1816         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1817         envp[2] = NULL;
1818         call_usermodehelper(argv[0], argv, envp, 1);
1819
1820         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1821         printk(KERN_INFO "Mandatory Access Control activated.\n");
1822         tomoyo_policy_loaded = true;
1823         { /* Check all profiles currently assigned to domains are defined. */
1824                 struct tomoyo_domain_info *domain;
1825                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1826                         const u8 profile = domain->profile;
1827                         if (tomoyo_profile_ptr[profile])
1828                                 continue;
1829                         panic("Profile %u (used by '%s') not defined.\n",
1830                               profile, domain->domainname->name);
1831                 }
1832         }
1833 }
1834
1835 /**
1836  * tomoyo_read_version: Get version.
1837  *
1838  * @head: Pointer to "struct tomoyo_io_buffer".
1839  *
1840  * Returns version information.
1841  */
1842 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1843 {
1844         if (!head->read_eof) {
1845                 tomoyo_io_printf(head, "2.2.0");
1846                 head->read_eof = true;
1847         }
1848         return 0;
1849 }
1850
1851 /**
1852  * tomoyo_read_self_domain - Get the current process's domainname.
1853  *
1854  * @head: Pointer to "struct tomoyo_io_buffer".
1855  *
1856  * Returns the current process's domainname.
1857  */
1858 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1859 {
1860         if (!head->read_eof) {
1861                 /*
1862                  * tomoyo_domain()->domainname != NULL
1863                  * because every process belongs to a domain and
1864                  * the domain's name cannot be NULL.
1865                  */
1866                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1867                 head->read_eof = true;
1868         }
1869         return 0;
1870 }
1871
1872 /**
1873  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1874  *
1875  * @type: Type of interface.
1876  * @file: Pointer to "struct file".
1877  *
1878  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1879  *
1880  * Caller acquires tomoyo_read_lock().
1881  */
1882 static int tomoyo_open_control(const u8 type, struct file *file)
1883 {
1884         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_NOFS);
1885
1886         if (!head)
1887                 return -ENOMEM;
1888         mutex_init(&head->io_sem);
1889         switch (type) {
1890         case TOMOYO_DOMAINPOLICY:
1891                 /* /sys/kernel/security/tomoyo/domain_policy */
1892                 head->write = tomoyo_write_domain_policy;
1893                 head->read = tomoyo_read_domain_policy;
1894                 break;
1895         case TOMOYO_EXCEPTIONPOLICY:
1896                 /* /sys/kernel/security/tomoyo/exception_policy */
1897                 head->write = tomoyo_write_exception_policy;
1898                 head->read = tomoyo_read_exception_policy;
1899                 break;
1900         case TOMOYO_SELFDOMAIN:
1901                 /* /sys/kernel/security/tomoyo/self_domain */
1902                 head->read = tomoyo_read_self_domain;
1903                 break;
1904         case TOMOYO_DOMAIN_STATUS:
1905                 /* /sys/kernel/security/tomoyo/.domain_status */
1906                 head->write = tomoyo_write_domain_profile;
1907                 head->read = tomoyo_read_domain_profile;
1908                 break;
1909         case TOMOYO_PROCESS_STATUS:
1910                 /* /sys/kernel/security/tomoyo/.process_status */
1911                 head->write = tomoyo_write_pid;
1912                 head->read = tomoyo_read_pid;
1913                 break;
1914         case TOMOYO_VERSION:
1915                 /* /sys/kernel/security/tomoyo/version */
1916                 head->read = tomoyo_read_version;
1917                 head->readbuf_size = 128;
1918                 break;
1919         case TOMOYO_MEMINFO:
1920                 /* /sys/kernel/security/tomoyo/meminfo */
1921                 head->write = tomoyo_write_memory_quota;
1922                 head->read = tomoyo_read_memory_counter;
1923                 head->readbuf_size = 512;
1924                 break;
1925         case TOMOYO_PROFILE:
1926                 /* /sys/kernel/security/tomoyo/profile */
1927                 head->write = tomoyo_write_profile;
1928                 head->read = tomoyo_read_profile;
1929                 break;
1930         case TOMOYO_MANAGER:
1931                 /* /sys/kernel/security/tomoyo/manager */
1932                 head->write = tomoyo_write_manager_policy;
1933                 head->read = tomoyo_read_manager_policy;
1934                 break;
1935         }
1936         if (!(file->f_mode & FMODE_READ)) {
1937                 /*
1938                  * No need to allocate read_buf since it is not opened
1939                  * for reading.
1940                  */
1941                 head->read = NULL;
1942         } else {
1943                 if (!head->readbuf_size)
1944                         head->readbuf_size = 4096 * 2;
1945                 head->read_buf = kzalloc(head->readbuf_size, GFP_NOFS);
1946                 if (!head->read_buf) {
1947                         kfree(head);
1948                         return -ENOMEM;
1949                 }
1950         }
1951         if (!(file->f_mode & FMODE_WRITE)) {
1952                 /*
1953                  * No need to allocate write_buf since it is not opened
1954                  * for writing.
1955                  */
1956                 head->write = NULL;
1957         } else if (head->write) {
1958                 head->writebuf_size = 4096 * 2;
1959                 head->write_buf = kzalloc(head->writebuf_size, GFP_NOFS);
1960                 if (!head->write_buf) {
1961                         kfree(head->read_buf);
1962                         kfree(head);
1963                         return -ENOMEM;
1964                 }
1965         }
1966         head->reader_idx = tomoyo_read_lock();
1967         file->private_data = head;
1968         /*
1969          * Call the handler now if the file is
1970          * /sys/kernel/security/tomoyo/self_domain
1971          * so that the user can use
1972          * cat < /sys/kernel/security/tomoyo/self_domain"
1973          * to know the current process's domainname.
1974          */
1975         if (type == TOMOYO_SELFDOMAIN)
1976                 tomoyo_read_control(file, NULL, 0);
1977         return 0;
1978 }
1979
1980 /**
1981  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1982  *
1983  * @file:       Pointer to "struct file".
1984  * @buffer:     Poiner to buffer to write to.
1985  * @buffer_len: Size of @buffer.
1986  *
1987  * Returns bytes read on success, negative value otherwise.
1988  *
1989  * Caller holds tomoyo_read_lock().
1990  */
1991 static int tomoyo_read_control(struct file *file, char __user *buffer,
1992                                const int buffer_len)
1993 {
1994         int len = 0;
1995         struct tomoyo_io_buffer *head = file->private_data;
1996         char *cp;
1997
1998         if (!head->read)
1999                 return -ENOSYS;
2000         if (mutex_lock_interruptible(&head->io_sem))
2001                 return -EINTR;
2002         /* Call the policy handler. */
2003         len = head->read(head);
2004         if (len < 0)
2005                 goto out;
2006         /* Write to buffer. */
2007         len = head->read_avail;
2008         if (len > buffer_len)
2009                 len = buffer_len;
2010         if (!len)
2011                 goto out;
2012         /* head->read_buf changes by some functions. */
2013         cp = head->read_buf;
2014         if (copy_to_user(buffer, cp, len)) {
2015                 len = -EFAULT;
2016                 goto out;
2017         }
2018         head->read_avail -= len;
2019         memmove(cp, cp + len, head->read_avail);
2020  out:
2021         mutex_unlock(&head->io_sem);
2022         return len;
2023 }
2024
2025 /**
2026  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2027  *
2028  * @file:       Pointer to "struct file".
2029  * @buffer:     Pointer to buffer to read from.
2030  * @buffer_len: Size of @buffer.
2031  *
2032  * Returns @buffer_len on success, negative value otherwise.
2033  *
2034  * Caller holds tomoyo_read_lock().
2035  */
2036 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2037                                 const int buffer_len)
2038 {
2039         struct tomoyo_io_buffer *head = file->private_data;
2040         int error = buffer_len;
2041         int avail_len = buffer_len;
2042         char *cp0 = head->write_buf;
2043
2044         if (!head->write)
2045                 return -ENOSYS;
2046         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2047                 return -EFAULT;
2048         /* Don't allow updating policies by non manager programs. */
2049         if (head->write != tomoyo_write_pid &&
2050             head->write != tomoyo_write_domain_policy &&
2051             !tomoyo_is_policy_manager())
2052                 return -EPERM;
2053         if (mutex_lock_interruptible(&head->io_sem))
2054                 return -EINTR;
2055         /* Read a line and dispatch it to the policy handler. */
2056         while (avail_len > 0) {
2057                 char c;
2058                 if (head->write_avail >= head->writebuf_size - 1) {
2059                         error = -ENOMEM;
2060                         break;
2061                 } else if (get_user(c, buffer)) {
2062                         error = -EFAULT;
2063                         break;
2064                 }
2065                 buffer++;
2066                 avail_len--;
2067                 cp0[head->write_avail++] = c;
2068                 if (c != '\n')
2069                         continue;
2070                 cp0[head->write_avail - 1] = '\0';
2071                 head->write_avail = 0;
2072                 tomoyo_normalize_line(cp0);
2073                 head->write(head);
2074         }
2075         mutex_unlock(&head->io_sem);
2076         return error;
2077 }
2078
2079 /**
2080  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2081  *
2082  * @file: Pointer to "struct file".
2083  *
2084  * Releases memory and returns 0.
2085  *
2086  * Caller looses tomoyo_read_lock().
2087  */
2088 static int tomoyo_close_control(struct file *file)
2089 {
2090         struct tomoyo_io_buffer *head = file->private_data;
2091         const bool is_write = !!head->write_buf;
2092
2093         tomoyo_read_unlock(head->reader_idx);
2094         /* Release memory used for policy I/O. */
2095         kfree(head->read_buf);
2096         head->read_buf = NULL;
2097         kfree(head->write_buf);
2098         head->write_buf = NULL;
2099         kfree(head);
2100         head = NULL;
2101         file->private_data = NULL;
2102         if (is_write)
2103                 tomoyo_run_gc();
2104         return 0;
2105 }
2106
2107 /**
2108  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2109  *
2110  * @inode: Pointer to "struct inode".
2111  * @file:  Pointer to "struct file".
2112  *
2113  * Returns 0 on success, negative value otherwise.
2114  */
2115 static int tomoyo_open(struct inode *inode, struct file *file)
2116 {
2117         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2118                 - ((u8 *) NULL);
2119         return tomoyo_open_control(key, file);
2120 }
2121
2122 /**
2123  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2124  *
2125  * @inode: Pointer to "struct inode".
2126  * @file:  Pointer to "struct file".
2127  *
2128  * Returns 0 on success, negative value otherwise.
2129  */
2130 static int tomoyo_release(struct inode *inode, struct file *file)
2131 {
2132         return tomoyo_close_control(file);
2133 }
2134
2135 /**
2136  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2137  *
2138  * @file:  Pointer to "struct file".
2139  * @buf:   Pointer to buffer.
2140  * @count: Size of @buf.
2141  * @ppos:  Unused.
2142  *
2143  * Returns bytes read on success, negative value otherwise.
2144  */
2145 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2146                            loff_t *ppos)
2147 {
2148         return tomoyo_read_control(file, buf, count);
2149 }
2150
2151 /**
2152  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2153  *
2154  * @file:  Pointer to "struct file".
2155  * @buf:   Pointer to buffer.
2156  * @count: Size of @buf.
2157  * @ppos:  Unused.
2158  *
2159  * Returns @count on success, negative value otherwise.
2160  */
2161 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2162                             size_t count, loff_t *ppos)
2163 {
2164         return tomoyo_write_control(file, buf, count);
2165 }
2166
2167 /*
2168  * tomoyo_operations is a "struct file_operations" which is used for handling
2169  * /sys/kernel/security/tomoyo/ interface.
2170  *
2171  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2172  * See tomoyo_io_buffer for internals.
2173  */
2174 static const struct file_operations tomoyo_operations = {
2175         .open    = tomoyo_open,
2176         .release = tomoyo_release,
2177         .read    = tomoyo_read,
2178         .write   = tomoyo_write,
2179 };
2180
2181 /**
2182  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2183  *
2184  * @name:   The name of the interface file.
2185  * @mode:   The permission of the interface file.
2186  * @parent: The parent directory.
2187  * @key:    Type of interface.
2188  *
2189  * Returns nothing.
2190  */
2191 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2192                                        struct dentry *parent, const u8 key)
2193 {
2194         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2195                                &tomoyo_operations);
2196 }
2197
2198 /**
2199  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2200  *
2201  * Returns 0.
2202  */
2203 static int __init tomoyo_initerface_init(void)
2204 {
2205         struct dentry *tomoyo_dir;
2206
2207         /* Don't create securityfs entries unless registered. */
2208         if (current_cred()->security != &tomoyo_kernel_domain)
2209                 return 0;
2210
2211         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2212         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2213                             TOMOYO_DOMAINPOLICY);
2214         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2215                             TOMOYO_EXCEPTIONPOLICY);
2216         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2217                             TOMOYO_SELFDOMAIN);
2218         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2219                             TOMOYO_DOMAIN_STATUS);
2220         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2221                             TOMOYO_PROCESS_STATUS);
2222         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2223                             TOMOYO_MEMINFO);
2224         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2225                             TOMOYO_PROFILE);
2226         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2227                             TOMOYO_MANAGER);
2228         tomoyo_create_entry("version",          0400, tomoyo_dir,
2229                             TOMOYO_VERSION);
2230         return 0;
2231 }
2232
2233 fs_initcall(tomoyo_initerface_init);