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   1 /*
   2  * security/tomoyo/common.c
   3  *
   4  * Common functions for TOMOYO.
   5  *
   6  * Copyright (C) 2005-2009  NTT DATA CORPORATION
   7  *
   8  * Version: 2.2.0   2009/04/01
   9  *
  10  */
  11
  12 #include <linux/uaccess.h>
  13 #include <linux/security.h>
  14 #include <linux/hardirq.h>
  15 #include "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 kzalloc(), so the caller must call kfree()
 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                 switch (ptr->type) {
 846                         struct tomoyo_single_path_acl_record *acl;
 847                         u32 perm;
 848                         u8 i;
 849                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
 850                         acl = container_of(ptr,
 851                                            struct tomoyo_single_path_acl_record,
 852                                            head);
 853                         perm = acl->perm | (((u32) acl->perm_high) << 16);
 854                         for (i = 0; i < TOMOYO_MAX_SINGLE_PATH_OPERATION; i++)
 855                                 if (perm & (1 << i))
 856                                         count++;
 857                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL))
 858                                 count -= 2;
 859                         break;
 860                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
 861                         perm = container_of(ptr,
 862                                     struct tomoyo_double_path_acl_record,
 863                                             head)->perm;
 864                         for (i = 0; i < TOMOYO_MAX_DOUBLE_PATH_OPERATION; i++)
 865                                 if (perm & (1 << i))
 866                                         count++;
 867                         break;
 868                 }
 869         }
 870         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 871                 return true;
 872         if (!domain->quota_warned) {
 873                 domain->quota_warned = true;
 874                 printk(KERN_WARNING "TOMOYO-WARNING: "
 875                        "Domain '%s' has so many ACLs to hold. "
 876                        "Stopped learning mode.\n", domain->domainname->name);
 877         }
 878         return false;
 879 }
 880
 881 /**
 882  * tomoyo_find_or_assign_new_profile - Create a new profile.
 883  *
 884  * @profile: Profile number to create.
 885  *
 886  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 887  */
 888 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 889                                                                 int profile)
 890 {
 891         static DEFINE_MUTEX(lock);
 892         struct tomoyo_profile *ptr = NULL;
 893         int i;
 894
 895         if (profile >= TOMOYO_MAX_PROFILES)
 896                 return NULL;
 897         mutex_lock(&lock);
 898         ptr = tomoyo_profile_ptr[profile];
 899         if (ptr)
 900                 goto ok;
 901         ptr = kmalloc(sizeof(*ptr), GFP_KERNEL);
 902         if (!tomoyo_memory_ok(ptr)) {
 903                 kfree(ptr);
 904                 goto ok;
 905         }
 906         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 907                 ptr->value[i] = tomoyo_control_array[i].current_value;
 908         mb(); /* Avoid out-of-order execution. */
 909         tomoyo_profile_ptr[profile] = ptr;
 910  ok:
 911         mutex_unlock(&lock);
 912         return ptr;
 913 }
 914
 915 /**
 916  * tomoyo_write_profile - Write to profile table.
 917  *
 918  * @head: Pointer to "struct tomoyo_io_buffer".
 919  *
 920  * Returns 0 on success, negative value otherwise.
 921  */
 922 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 923 {
 924         char *data = head->write_buf;
 925         unsigned int i;
 926         unsigned int value;
 927         char *cp;
 928         struct tomoyo_profile *profile;
 929         unsigned long num;
 930
 931         cp = strchr(data, '-');
 932         if (cp)
 933                 *cp = '\0';
 934         if (strict_strtoul(data, 10, &num))
 935                 return -EINVAL;
 936         if (cp)
 937                 data = cp + 1;
 938         profile = tomoyo_find_or_assign_new_profile(num);
 939         if (!profile)
 940                 return -EINVAL;
 941         cp = strchr(data, '=');
 942         if (!cp)
 943                 return -EINVAL;
 944         *cp = '\0';
 945         if (!strcmp(data, "COMMENT")) {
 946                 profile->comment = tomoyo_save_name(cp + 1);
 947                 return 0;
 948         }
 949         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 950                 if (strcmp(data, tomoyo_control_array[i].keyword))
 951                         continue;
 952                 if (sscanf(cp + 1, "%u", &value) != 1) {
 953                         int j;
 954                         const char **modes;
 955                         switch (i) {
 956                         case TOMOYO_VERBOSE:
 957                                 modes = tomoyo_mode_2;
 958                                 break;
 959                         default:
 960                                 modes = tomoyo_mode_4;
 961                                 break;
 962                         }
 963                         for (j = 0; j < 4; j++) {
 964                                 if (strcmp(cp + 1, modes[j]))
 965                                         continue;
 966                                 value = j;
 967                                 break;
 968                         }
 969                         if (j == 4)
 970                                 return -EINVAL;
 971                 } else if (value > tomoyo_control_array[i].max_value) {
 972                         value = tomoyo_control_array[i].max_value;
 973                 }
 974                 profile->value[i] = value;
 975                 return 0;
 976         }
 977         return -EINVAL;
 978 }
 979
 980 /**
 981  * tomoyo_read_profile - Read from profile table.
 982  *
 983  * @head: Pointer to "struct tomoyo_io_buffer".
 984  *
 985  * Returns 0.
 986  */
 987 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 988 {
 989         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 990         int step;
 991
 992         if (head->read_eof)
 993                 return 0;
 994         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 995              step++) {
 996                 const u8 index = step / total;
 997                 u8 type = step % total;
 998                 const struct tomoyo_profile *profile
 999                         = tomoyo_profile_ptr[index];
1000                 head->read_step = step;
1001                 if (!profile)
1002                         continue;
1003                 if (!type) { /* Print profile' comment tag. */
1004                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
1005                                               index, profile->comment ?
1006                                               profile->comment->name : ""))
1007                                 break;
1008                         continue;
1009                 }
1010                 type--;
1011                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1012                         const unsigned int value = profile->value[type];
1013                         const char **modes = NULL;
1014                         const char *keyword
1015                                 = tomoyo_control_array[type].keyword;
1016                         switch (tomoyo_control_array[type].max_value) {
1017                         case 3:
1018                                 modes = tomoyo_mode_4;
1019                                 break;
1020                         case 1:
1021                                 modes = tomoyo_mode_2;
1022                                 break;
1023                         }
1024                         if (modes) {
1025                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1026                                                       keyword, modes[value]))
1027                                         break;
1028                         } else {
1029                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1030                                                       keyword, value))
1031                                         break;
1032                         }
1033                 }
1034         }
1035         if (step == TOMOYO_MAX_PROFILES * total)
1036                 head->read_eof = true;
1037         return 0;
1038 }
1039
1040 /*
1041  * tomoyo_policy_manager_entry is a structure which is used for holding list of
1042  * domainnames or programs which are permitted to modify configuration via
1043  * /sys/kernel/security/tomoyo/ interface.
1044  * It has following fields.
1045  *
1046  *  (1) "list" which is linked to tomoyo_policy_manager_list .
1047  *  (2) "manager" is a domainname or a program's pathname.
1048  *  (3) "is_domain" is a bool which is true if "manager" is a domainname, false
1049  *      otherwise.
1050  *  (4) "is_deleted" is a bool which is true if marked as deleted, false
1051  *      otherwise.
1052  */
1053 struct tomoyo_policy_manager_entry {
1054         struct list_head list;
1055         /* A path to program or a domainname. */
1056         const struct tomoyo_path_info *manager;
1057         bool is_domain;  /* True if manager is a domainname. */
1058         bool is_deleted; /* True if this entry is deleted. */
1059 };
1060
1061 /*
1062  * tomoyo_policy_manager_list is used for holding list of domainnames or
1063  * programs which are permitted to modify configuration via
1064  * /sys/kernel/security/tomoyo/ interface.
1065  *
1066  * An entry is added by
1067  *
1068  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1069  *                                        /sys/kernel/security/tomoyo/manager
1070  *  (if you want to specify by a domainname)
1071  *
1072  *  or
1073  *
1074  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1075  *  (if you want to specify by a program's location)
1076  *
1077  * and is deleted by
1078  *
1079  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1080  *                                        /sys/kernel/security/tomoyo/manager
1081  *
1082  *  or
1083  *
1084  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1085  *                                        /sys/kernel/security/tomoyo/manager
1086  *
1087  * and all entries are retrieved by
1088  *
1089  * # cat /sys/kernel/security/tomoyo/manager
1090  */
1091 static LIST_HEAD(tomoyo_policy_manager_list);
1092
1093 /**
1094  * tomoyo_update_manager_entry - Add a manager entry.
1095  *
1096  * @manager:   The path to manager or the domainnamme.
1097  * @is_delete: True if it is a delete request.
1098  *
1099  * Returns 0 on success, negative value otherwise.
1100  *
1101  * Caller holds tomoyo_read_lock().
1102  */
1103 static int tomoyo_update_manager_entry(const char *manager,
1104                                        const bool is_delete)
1105 {
1106         struct tomoyo_policy_manager_entry *entry = NULL;
1107         struct tomoyo_policy_manager_entry *ptr;
1108         const struct tomoyo_path_info *saved_manager;
1109         int error = is_delete ? -ENOENT : -ENOMEM;
1110         bool is_domain = false;
1111
1112         if (tomoyo_is_domain_def(manager)) {
1113                 if (!tomoyo_is_correct_domain(manager, __func__))
1114                         return -EINVAL;
1115                 is_domain = true;
1116         } else {
1117                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1118                         return -EINVAL;
1119         }
1120         saved_manager = tomoyo_save_name(manager);
1121         if (!saved_manager)
1122                 return -ENOMEM;
1123         if (!is_delete)
1124                 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1125         mutex_lock(&tomoyo_policy_lock);
1126         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1127                 if (ptr->manager != saved_manager)
1128                         continue;
1129                 ptr->is_deleted = is_delete;
1130                 error = 0;
1131                 break;
1132         }
1133         if (!is_delete && error && tomoyo_memory_ok(entry)) {
1134                 entry->manager = saved_manager;
1135                 entry->is_domain = is_domain;
1136                 list_add_tail_rcu(&entry->list, &tomoyo_policy_manager_list);
1137                 entry = NULL;
1138                 error = 0;
1139         }
1140         mutex_unlock(&tomoyo_policy_lock);
1141         kfree(entry);
1142         return error;
1143 }
1144
1145 /**
1146  * tomoyo_write_manager_policy - Write manager policy.
1147  *
1148  * @head: Pointer to "struct tomoyo_io_buffer".
1149  *
1150  * Returns 0 on success, negative value otherwise.
1151  *
1152  * Caller holds tomoyo_read_lock().
1153  */
1154 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1155 {
1156         char *data = head->write_buf;
1157         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1158
1159         if (!strcmp(data, "manage_by_non_root")) {
1160                 tomoyo_manage_by_non_root = !is_delete;
1161                 return 0;
1162         }
1163         return tomoyo_update_manager_entry(data, is_delete);
1164 }
1165
1166 /**
1167  * tomoyo_read_manager_policy - Read manager policy.
1168  *
1169  * @head: Pointer to "struct tomoyo_io_buffer".
1170  *
1171  * Returns 0.
1172  *
1173  * Caller holds tomoyo_read_lock().
1174  */
1175 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1176 {
1177         struct list_head *pos;
1178         bool done = true;
1179
1180         if (head->read_eof)
1181                 return 0;
1182         list_for_each_cookie(pos, head->read_var2,
1183                              &tomoyo_policy_manager_list) {
1184                 struct tomoyo_policy_manager_entry *ptr;
1185                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1186                                  list);
1187                 if (ptr->is_deleted)
1188                         continue;
1189                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1190                 if (!done)
1191                         break;
1192         }
1193         head->read_eof = done;
1194         return 0;
1195 }
1196
1197 /**
1198  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1199  *
1200  * Returns true if the current process is permitted to modify policy
1201  * via /sys/kernel/security/tomoyo/ interface.
1202  *
1203  * Caller holds tomoyo_read_lock().
1204  */
1205 static bool tomoyo_is_policy_manager(void)
1206 {
1207         struct tomoyo_policy_manager_entry *ptr;
1208         const char *exe;
1209         const struct task_struct *task = current;
1210         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1211         bool found = false;
1212
1213         if (!tomoyo_policy_loaded)
1214                 return true;
1215         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1216                 return false;
1217         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1218                 if (!ptr->is_deleted && ptr->is_domain
1219                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1220                         found = true;
1221                         break;
1222                 }
1223         }
1224         if (found)
1225                 return true;
1226         exe = tomoyo_get_exe();
1227         if (!exe)
1228                 return false;
1229         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1230                 if (!ptr->is_deleted && !ptr->is_domain
1231                     && !strcmp(exe, ptr->manager->name)) {
1232                         found = true;
1233                         break;
1234                 }
1235         }
1236         if (!found) { /* Reduce error messages. */
1237                 static pid_t last_pid;
1238                 const pid_t pid = current->pid;
1239                 if (last_pid != pid) {
1240                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1241                                "update policies.\n", domainname->name, exe);
1242                         last_pid = pid;
1243                 }
1244         }
1245         kfree(exe);
1246         return found;
1247 }
1248
1249 /**
1250  * tomoyo_is_select_one - Parse select command.
1251  *
1252  * @head: Pointer to "struct tomoyo_io_buffer".
1253  * @data: String to parse.
1254  *
1255  * Returns true on success, false otherwise.
1256  *
1257  * Caller holds tomoyo_read_lock().
1258  */
1259 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1260                                  const char *data)
1261 {
1262         unsigned int pid;
1263         struct tomoyo_domain_info *domain = NULL;
1264
1265         if (sscanf(data, "pid=%u", &pid) == 1) {
1266                 struct task_struct *p;
1267                 read_lock(&tasklist_lock);
1268                 p = find_task_by_vpid(pid);
1269                 if (p)
1270                         domain = tomoyo_real_domain(p);
1271                 read_unlock(&tasklist_lock);
1272         } else if (!strncmp(data, "domain=", 7)) {
1273                 if (tomoyo_is_domain_def(data + 7))
1274                         domain = tomoyo_find_domain(data + 7);
1275         } else
1276                 return false;
1277         head->write_var1 = domain;
1278         /* Accessing read_buf is safe because head->io_sem is held. */
1279         if (!head->read_buf)
1280                 return true; /* Do nothing if open(O_WRONLY). */
1281         head->read_avail = 0;
1282         tomoyo_io_printf(head, "# select %s\n", data);
1283         head->read_single_domain = true;
1284         head->read_eof = !domain;
1285         if (domain) {
1286                 struct tomoyo_domain_info *d;
1287                 head->read_var1 = NULL;
1288                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1289                         if (d == domain)
1290                                 break;
1291                         head->read_var1 = &d->list;
1292                 }
1293                 head->read_var2 = NULL;
1294                 head->read_bit = 0;
1295                 head->read_step = 0;
1296                 if (domain->is_deleted)
1297                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1298         }
1299         return true;
1300 }
1301
1302 /**
1303  * tomoyo_delete_domain - Delete a domain.
1304  *
1305  * @domainname: The name of domain.
1306  *
1307  * Returns 0.
1308  *
1309  * Caller holds tomoyo_read_lock().
1310  */
1311 static int tomoyo_delete_domain(char *domainname)
1312 {
1313         struct tomoyo_domain_info *domain;
1314         struct tomoyo_path_info name;
1315
1316         name.name = domainname;
1317         tomoyo_fill_path_info(&name);
1318         mutex_lock(&tomoyo_policy_lock);
1319         /* Is there an active domain? */
1320         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1321                 /* Never delete tomoyo_kernel_domain */
1322                 if (domain == &tomoyo_kernel_domain)
1323                         continue;
1324                 if (domain->is_deleted ||
1325                     tomoyo_pathcmp(domain->domainname, &name))
1326                         continue;
1327                 domain->is_deleted = true;
1328                 break;
1329         }
1330         mutex_unlock(&tomoyo_policy_lock);
1331         return 0;
1332 }
1333
1334 /**
1335  * tomoyo_write_domain_policy - Write domain policy.
1336  *
1337  * @head: Pointer to "struct tomoyo_io_buffer".
1338  *
1339  * Returns 0 on success, negative value otherwise.
1340  *
1341  * Caller holds tomoyo_read_lock().
1342  */
1343 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1344 {
1345         char *data = head->write_buf;
1346         struct tomoyo_domain_info *domain = head->write_var1;
1347         bool is_delete = false;
1348         bool is_select = false;
1349         unsigned int profile;
1350
1351         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1352                 is_delete = true;
1353         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1354                 is_select = true;
1355         if (is_select && tomoyo_is_select_one(head, data))
1356                 return 0;
1357         /* Don't allow updating policies by non manager programs. */
1358         if (!tomoyo_is_policy_manager())
1359                 return -EPERM;
1360         if (tomoyo_is_domain_def(data)) {
1361                 domain = NULL;
1362                 if (is_delete)
1363                         tomoyo_delete_domain(data);
1364                 else if (is_select)
1365                         domain = tomoyo_find_domain(data);
1366                 else
1367                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1368                 head->write_var1 = domain;
1369                 return 0;
1370         }
1371         if (!domain)
1372                 return -EINVAL;
1373
1374         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1375             && profile < TOMOYO_MAX_PROFILES) {
1376                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1377                         domain->profile = (u8) profile;
1378                 return 0;
1379         }
1380         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1381                 domain->ignore_global_allow_read = !is_delete;
1382                 return 0;
1383         }
1384         return tomoyo_write_file_policy(data, domain, is_delete);
1385 }
1386
1387 /**
1388  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1389  *
1390  * @head: Pointer to "struct tomoyo_io_buffer".
1391  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1392  *
1393  * Returns true on success, false otherwise.
1394  */
1395 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1396                                          struct tomoyo_single_path_acl_record *
1397                                          ptr)
1398 {
1399         int pos;
1400         u8 bit;
1401         const char *atmark = "";
1402         const char *filename;
1403         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1404
1405         filename = ptr->filename->name;
1406         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1407              bit++) {
1408                 const char *msg;
1409                 if (!(perm & (1 << bit)))
1410                         continue;
1411                 /* Print "read/write" instead of "read" and "write". */
1412                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1413                      bit == TOMOYO_TYPE_WRITE_ACL)
1414                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1415                         continue;
1416                 msg = tomoyo_sp2keyword(bit);
1417                 pos = head->read_avail;
1418                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1419                                       atmark, filename))
1420                         goto out;
1421         }
1422         head->read_bit = 0;
1423         return true;
1424  out:
1425         head->read_bit = bit;
1426         head->read_avail = pos;
1427         return false;
1428 }
1429
1430 /**
1431  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1432  *
1433  * @head: Pointer to "struct tomoyo_io_buffer".
1434  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1435  *
1436  * Returns true on success, false otherwise.
1437  */
1438 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1439                                          struct tomoyo_double_path_acl_record *
1440                                          ptr)
1441 {
1442         int pos;
1443         const char *atmark1 = "";
1444         const char *atmark2 = "";
1445         const char *filename1;
1446         const char *filename2;
1447         const u8 perm = ptr->perm;
1448         u8 bit;
1449
1450         filename1 = ptr->filename1->name;
1451         filename2 = ptr->filename2->name;
1452         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1453              bit++) {
1454                 const char *msg;
1455                 if (!(perm & (1 << bit)))
1456                         continue;
1457                 msg = tomoyo_dp2keyword(bit);
1458                 pos = head->read_avail;
1459                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1460                                       atmark1, filename1, atmark2, filename2))
1461                         goto out;
1462         }
1463         head->read_bit = 0;
1464         return true;
1465  out:
1466         head->read_bit = bit;
1467         head->read_avail = pos;
1468         return false;
1469 }
1470
1471 /**
1472  * tomoyo_print_entry - Print an ACL entry.
1473  *
1474  * @head: Pointer to "struct tomoyo_io_buffer".
1475  * @ptr:  Pointer to an ACL entry.
1476  *
1477  * Returns true on success, false otherwise.
1478  */
1479 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1480                                struct tomoyo_acl_info *ptr)
1481 {
1482         const u8 acl_type = ptr->type;
1483
1484         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1485                 struct tomoyo_single_path_acl_record *acl
1486                         = container_of(ptr,
1487                                        struct tomoyo_single_path_acl_record,
1488                                        head);
1489                 return tomoyo_print_single_path_acl(head, acl);
1490         }
1491         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1492                 struct tomoyo_double_path_acl_record *acl
1493                         = container_of(ptr,
1494                                        struct tomoyo_double_path_acl_record,
1495                                        head);
1496                 return tomoyo_print_double_path_acl(head, acl);
1497         }
1498         BUG(); /* This must not happen. */
1499         return false;
1500 }
1501
1502 /**
1503  * tomoyo_read_domain_policy - Read domain policy.
1504  *
1505  * @head: Pointer to "struct tomoyo_io_buffer".
1506  *
1507  * Returns 0.
1508  *
1509  * Caller holds tomoyo_read_lock().
1510  */
1511 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1512 {
1513         struct list_head *dpos;
1514         struct list_head *apos;
1515         bool done = true;
1516
1517         if (head->read_eof)
1518                 return 0;
1519         if (head->read_step == 0)
1520                 head->read_step = 1;
1521         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1522                 struct tomoyo_domain_info *domain;
1523                 const char *quota_exceeded = "";
1524                 const char *transition_failed = "";
1525                 const char *ignore_global_allow_read = "";
1526                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1527                 if (head->read_step != 1)
1528                         goto acl_loop;
1529                 if (domain->is_deleted && !head->read_single_domain)
1530                         continue;
1531                 /* Print domainname and flags. */
1532                 if (domain->quota_warned)
1533                         quota_exceeded = "quota_exceeded\n";
1534                 if (domain->transition_failed)
1535                         transition_failed = "transition_failed\n";
1536                 if (domain->ignore_global_allow_read)
1537                         ignore_global_allow_read
1538                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1539                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1540                                         "%u\n%s%s%s\n",
1541                                         domain->domainname->name,
1542                                         domain->profile, quota_exceeded,
1543                                         transition_failed,
1544                                         ignore_global_allow_read);
1545                 if (!done)
1546                         break;
1547                 head->read_step = 2;
1548 acl_loop:
1549                 if (head->read_step == 3)
1550                         goto tail_mark;
1551                 /* Print ACL entries in the domain. */
1552                 list_for_each_cookie(apos, head->read_var2,
1553                                      &domain->acl_info_list) {
1554                         struct tomoyo_acl_info *ptr
1555                                 = list_entry(apos, struct tomoyo_acl_info,
1556                                              list);
1557                         done = tomoyo_print_entry(head, ptr);
1558                         if (!done)
1559                                 break;
1560                 }
1561                 if (!done)
1562                         break;
1563                 head->read_step = 3;
1564 tail_mark:
1565                 done = tomoyo_io_printf(head, "\n");
1566                 if (!done)
1567                         break;
1568                 head->read_step = 1;
1569                 if (head->read_single_domain)
1570                         break;
1571         }
1572         head->read_eof = done;
1573         return 0;
1574 }
1575
1576 /**
1577  * tomoyo_write_domain_profile - Assign profile for specified domain.
1578  *
1579  * @head: Pointer to "struct tomoyo_io_buffer".
1580  *
1581  * Returns 0 on success, -EINVAL otherwise.
1582  *
1583  * This is equivalent to doing
1584  *
1585  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1586  *     /usr/lib/ccs/loadpolicy -d
1587  *
1588  * Caller holds tomoyo_read_lock().
1589  */
1590 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1591 {
1592         char *data = head->write_buf;
1593         char *cp = strchr(data, ' ');
1594         struct tomoyo_domain_info *domain;
1595         unsigned long profile;
1596
1597         if (!cp)
1598                 return -EINVAL;
1599         *cp = '\0';
1600         domain = tomoyo_find_domain(cp + 1);
1601         if (strict_strtoul(data, 10, &profile))
1602                 return -EINVAL;
1603         if (domain && profile < TOMOYO_MAX_PROFILES
1604             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1605                 domain->profile = (u8) profile;
1606         return 0;
1607 }
1608
1609 /**
1610  * tomoyo_read_domain_profile - Read only domainname and profile.
1611  *
1612  * @head: Pointer to "struct tomoyo_io_buffer".
1613  *
1614  * Returns list of profile number and domainname pairs.
1615  *
1616  * This is equivalent to doing
1617  *
1618  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1619  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1620  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1621  *     print $2 " " domainname; domainname = ""; } } ; '
1622  *
1623  * Caller holds tomoyo_read_lock().
1624  */
1625 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1626 {
1627         struct list_head *pos;
1628         bool done = true;
1629
1630         if (head->read_eof)
1631                 return 0;
1632         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1633                 struct tomoyo_domain_info *domain;
1634                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1635                 if (domain->is_deleted)
1636                         continue;
1637                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1638                                         domain->domainname->name);
1639                 if (!done)
1640                         break;
1641         }
1642         head->read_eof = done;
1643         return 0;
1644 }
1645
1646 /**
1647  * tomoyo_write_pid: Specify PID to obtain domainname.
1648  *
1649  * @head: Pointer to "struct tomoyo_io_buffer".
1650  *
1651  * Returns 0.
1652  */
1653 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1654 {
1655         unsigned long pid;
1656         /* No error check. */
1657         strict_strtoul(head->write_buf, 10, &pid);
1658         head->read_step = (int) pid;
1659         head->read_eof = false;
1660         return 0;
1661 }
1662
1663 /**
1664  * tomoyo_read_pid - Get domainname of the specified PID.
1665  *
1666  * @head: Pointer to "struct tomoyo_io_buffer".
1667  *
1668  * Returns the domainname which the specified PID is in on success,
1669  * empty string otherwise.
1670  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1671  * using read()/write() interface rather than sysctl() interface.
1672  */
1673 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1674 {
1675         if (head->read_avail == 0 && !head->read_eof) {
1676                 const int pid = head->read_step;
1677                 struct task_struct *p;
1678                 struct tomoyo_domain_info *domain = NULL;
1679                 read_lock(&tasklist_lock);
1680                 p = find_task_by_vpid(pid);
1681                 if (p)
1682                         domain = tomoyo_real_domain(p);
1683                 read_unlock(&tasklist_lock);
1684                 if (domain)
1685                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1686                                          domain->domainname->name);
1687                 head->read_eof = true;
1688         }
1689         return 0;
1690 }
1691
1692 /**
1693  * tomoyo_write_exception_policy - Write exception policy.
1694  *
1695  * @head: Pointer to "struct tomoyo_io_buffer".
1696  *
1697  * Returns 0 on success, negative value otherwise.
1698  *
1699  * Caller holds tomoyo_read_lock().
1700  */
1701 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1702 {
1703         char *data = head->write_buf;
1704         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1705
1706         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1707                 return tomoyo_write_domain_keeper_policy(data, false,
1708                                                          is_delete);
1709         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1710                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1711         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1712                 return tomoyo_write_domain_initializer_policy(data, false,
1713                                                               is_delete);
1714         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1715                 return tomoyo_write_domain_initializer_policy(data, true,
1716                                                               is_delete);
1717         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1718                 return tomoyo_write_alias_policy(data, is_delete);
1719         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1720                 return tomoyo_write_globally_readable_policy(data, is_delete);
1721         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1722                 return tomoyo_write_pattern_policy(data, is_delete);
1723         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1724                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1725         return -EINVAL;
1726 }
1727
1728 /**
1729  * tomoyo_read_exception_policy - Read exception policy.
1730  *
1731  * @head: Pointer to "struct tomoyo_io_buffer".
1732  *
1733  * Returns 0 on success, -EINVAL otherwise.
1734  *
1735  * Caller holds tomoyo_read_lock().
1736  */
1737 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1738 {
1739         if (!head->read_eof) {
1740                 switch (head->read_step) {
1741                 case 0:
1742                         head->read_var2 = NULL;
1743                         head->read_step = 1;
1744                 case 1:
1745                         if (!tomoyo_read_domain_keeper_policy(head))
1746                                 break;
1747                         head->read_var2 = NULL;
1748                         head->read_step = 2;
1749                 case 2:
1750                         if (!tomoyo_read_globally_readable_policy(head))
1751                                 break;
1752                         head->read_var2 = NULL;
1753                         head->read_step = 3;
1754                 case 3:
1755                         head->read_var2 = NULL;
1756                         head->read_step = 4;
1757                 case 4:
1758                         if (!tomoyo_read_domain_initializer_policy(head))
1759                                 break;
1760                         head->read_var2 = NULL;
1761                         head->read_step = 5;
1762                 case 5:
1763                         if (!tomoyo_read_alias_policy(head))
1764                                 break;
1765                         head->read_var2 = NULL;
1766                         head->read_step = 6;
1767                 case 6:
1768                         head->read_var2 = NULL;
1769                         head->read_step = 7;
1770                 case 7:
1771                         if (!tomoyo_read_file_pattern(head))
1772                                 break;
1773                         head->read_var2 = NULL;
1774                         head->read_step = 8;
1775                 case 8:
1776                         if (!tomoyo_read_no_rewrite_policy(head))
1777                                 break;
1778                         head->read_var2 = NULL;
1779                         head->read_step = 9;
1780                 case 9:
1781                         head->read_eof = true;
1782                         break;
1783                 default:
1784                         return -EINVAL;
1785                 }
1786         }
1787         return 0;
1788 }
1789
1790 /* path to policy loader */
1791 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1792
1793 /**
1794  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1795  *
1796  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1797  */
1798 static bool tomoyo_policy_loader_exists(void)
1799 {
1800         /*
1801          * Don't activate MAC if the policy loader doesn't exist.
1802          * If the initrd includes /sbin/init but real-root-dev has not
1803          * mounted on / yet, activating MAC will block the system since
1804          * policies are not loaded yet.
1805          * Thus, let do_execve() call this function everytime.
1806          */
1807         struct path path;
1808
1809         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1810                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1811                        "since %s doesn't exist.\n", tomoyo_loader);
1812                 return false;
1813         }
1814         path_put(&path);
1815         return true;
1816 }
1817
1818 /**
1819  * tomoyo_load_policy - Run external policy loader to load policy.
1820  *
1821  * @filename: The program about to start.
1822  *
1823  * This function checks whether @filename is /sbin/init , and if so
1824  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1825  * and then continues invocation of /sbin/init.
1826  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1827  * writes to /sys/kernel/security/tomoyo/ interfaces.
1828  *
1829  * Returns nothing.
1830  */
1831 void tomoyo_load_policy(const char *filename)
1832 {
1833         char *argv[2];
1834         char *envp[3];
1835
1836         if (tomoyo_policy_loaded)
1837                 return;
1838         /*
1839          * Check filename is /sbin/init or /sbin/tomoyo-start.
1840          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1841          * be passed.
1842          * You can create /sbin/tomoyo-start by
1843          * "ln -s /bin/true /sbin/tomoyo-start".
1844          */
1845         if (strcmp(filename, "/sbin/init") &&
1846             strcmp(filename, "/sbin/tomoyo-start"))
1847                 return;
1848         if (!tomoyo_policy_loader_exists())
1849                 return;
1850
1851         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1852                tomoyo_loader);
1853         argv[0] = (char *) tomoyo_loader;
1854         argv[1] = NULL;
1855         envp[0] = "HOME=/";
1856         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1857         envp[2] = NULL;
1858         call_usermodehelper(argv[0], argv, envp, 1);
1859
1860         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1861         printk(KERN_INFO "Mandatory Access Control activated.\n");
1862         tomoyo_policy_loaded = true;
1863         { /* Check all profiles currently assigned to domains are defined. */
1864                 struct tomoyo_domain_info *domain;
1865                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1866                         const u8 profile = domain->profile;
1867                         if (tomoyo_profile_ptr[profile])
1868                                 continue;
1869                         panic("Profile %u (used by '%s') not defined.\n",
1870                               profile, domain->domainname->name);
1871                 }
1872         }
1873 }
1874
1875 /**
1876  * tomoyo_read_version: Get version.
1877  *
1878  * @head: Pointer to "struct tomoyo_io_buffer".
1879  *
1880  * Returns version information.
1881  */
1882 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1883 {
1884         if (!head->read_eof) {
1885                 tomoyo_io_printf(head, "2.2.0");
1886                 head->read_eof = true;
1887         }
1888         return 0;
1889 }
1890
1891 /**
1892  * tomoyo_read_self_domain - Get the current process's domainname.
1893  *
1894  * @head: Pointer to "struct tomoyo_io_buffer".
1895  *
1896  * Returns the current process's domainname.
1897  */
1898 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1899 {
1900         if (!head->read_eof) {
1901                 /*
1902                  * tomoyo_domain()->domainname != NULL
1903                  * because every process belongs to a domain and
1904                  * the domain's name cannot be NULL.
1905                  */
1906                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1907                 head->read_eof = true;
1908         }
1909         return 0;
1910 }
1911
1912 /**
1913  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1914  *
1915  * @type: Type of interface.
1916  * @file: Pointer to "struct file".
1917  *
1918  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1919  *
1920  * Caller acquires tomoyo_read_lock().
1921  */
1922 static int tomoyo_open_control(const u8 type, struct file *file)
1923 {
1924         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_KERNEL);
1925
1926         if (!head)
1927                 return -ENOMEM;
1928         mutex_init(&head->io_sem);
1929         switch (type) {
1930         case TOMOYO_DOMAINPOLICY:
1931                 /* /sys/kernel/security/tomoyo/domain_policy */
1932                 head->write = tomoyo_write_domain_policy;
1933                 head->read = tomoyo_read_domain_policy;
1934                 break;
1935         case TOMOYO_EXCEPTIONPOLICY:
1936                 /* /sys/kernel/security/tomoyo/exception_policy */
1937                 head->write = tomoyo_write_exception_policy;
1938                 head->read = tomoyo_read_exception_policy;
1939                 break;
1940         case TOMOYO_SELFDOMAIN:
1941                 /* /sys/kernel/security/tomoyo/self_domain */
1942                 head->read = tomoyo_read_self_domain;
1943                 break;
1944         case TOMOYO_DOMAIN_STATUS:
1945                 /* /sys/kernel/security/tomoyo/.domain_status */
1946                 head->write = tomoyo_write_domain_profile;
1947                 head->read = tomoyo_read_domain_profile;
1948                 break;
1949         case TOMOYO_PROCESS_STATUS:
1950                 /* /sys/kernel/security/tomoyo/.process_status */
1951                 head->write = tomoyo_write_pid;
1952                 head->read = tomoyo_read_pid;
1953                 break;
1954         case TOMOYO_VERSION:
1955                 /* /sys/kernel/security/tomoyo/version */
1956                 head->read = tomoyo_read_version;
1957                 head->readbuf_size = 128;
1958                 break;
1959         case TOMOYO_MEMINFO:
1960                 /* /sys/kernel/security/tomoyo/meminfo */
1961                 head->write = tomoyo_write_memory_quota;
1962                 head->read = tomoyo_read_memory_counter;
1963                 head->readbuf_size = 512;
1964                 break;
1965         case TOMOYO_PROFILE:
1966                 /* /sys/kernel/security/tomoyo/profile */
1967                 head->write = tomoyo_write_profile;
1968                 head->read = tomoyo_read_profile;
1969                 break;
1970         case TOMOYO_MANAGER:
1971                 /* /sys/kernel/security/tomoyo/manager */
1972                 head->write = tomoyo_write_manager_policy;
1973                 head->read = tomoyo_read_manager_policy;
1974                 break;
1975         }
1976         if (!(file->f_mode & FMODE_READ)) {
1977                 /*
1978                  * No need to allocate read_buf since it is not opened
1979                  * for reading.
1980                  */
1981                 head->read = NULL;
1982         } else {
1983                 if (!head->readbuf_size)
1984                         head->readbuf_size = 4096 * 2;
1985                 head->read_buf = kzalloc(head->readbuf_size, GFP_KERNEL);
1986                 if (!head->read_buf) {
1987                         kfree(head);
1988                         return -ENOMEM;
1989                 }
1990         }
1991         if (!(file->f_mode & FMODE_WRITE)) {
1992                 /*
1993                  * No need to allocate write_buf since it is not opened
1994                  * for writing.
1995                  */
1996                 head->write = NULL;
1997         } else if (head->write) {
1998                 head->writebuf_size = 4096 * 2;
1999                 head->write_buf = kzalloc(head->writebuf_size, GFP_KERNEL);
2000                 if (!head->write_buf) {
2001                         kfree(head->read_buf);
2002                         kfree(head);
2003                         return -ENOMEM;
2004                 }
2005         }
2006         head->reader_idx = tomoyo_read_lock();
2007         file->private_data = head;
2008         /*
2009          * Call the handler now if the file is
2010          * /sys/kernel/security/tomoyo/self_domain
2011          * so that the user can use
2012          * cat < /sys/kernel/security/tomoyo/self_domain"
2013          * to know the current process's domainname.
2014          */
2015         if (type == TOMOYO_SELFDOMAIN)
2016                 tomoyo_read_control(file, NULL, 0);
2017         return 0;
2018 }
2019
2020 /**
2021  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
2022  *
2023  * @file:       Pointer to "struct file".
2024  * @buffer:     Poiner to buffer to write to.
2025  * @buffer_len: Size of @buffer.
2026  *
2027  * Returns bytes read on success, negative value otherwise.
2028  *
2029  * Caller holds tomoyo_read_lock().
2030  */
2031 static int tomoyo_read_control(struct file *file, char __user *buffer,
2032                                const int buffer_len)
2033 {
2034         int len = 0;
2035         struct tomoyo_io_buffer *head = file->private_data;
2036         char *cp;
2037
2038         if (!head->read)
2039                 return -ENOSYS;
2040         if (mutex_lock_interruptible(&head->io_sem))
2041                 return -EINTR;
2042         /* Call the policy handler. */
2043         len = head->read(head);
2044         if (len < 0)
2045                 goto out;
2046         /* Write to buffer. */
2047         len = head->read_avail;
2048         if (len > buffer_len)
2049                 len = buffer_len;
2050         if (!len)
2051                 goto out;
2052         /* head->read_buf changes by some functions. */
2053         cp = head->read_buf;
2054         if (copy_to_user(buffer, cp, len)) {
2055                 len = -EFAULT;
2056                 goto out;
2057         }
2058         head->read_avail -= len;
2059         memmove(cp, cp + len, head->read_avail);
2060  out:
2061         mutex_unlock(&head->io_sem);
2062         return len;
2063 }
2064
2065 /**
2066  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2067  *
2068  * @file:       Pointer to "struct file".
2069  * @buffer:     Pointer to buffer to read from.
2070  * @buffer_len: Size of @buffer.
2071  *
2072  * Returns @buffer_len on success, negative value otherwise.
2073  *
2074  * Caller holds tomoyo_read_lock().
2075  */
2076 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2077                                 const int buffer_len)
2078 {
2079         struct tomoyo_io_buffer *head = file->private_data;
2080         int error = buffer_len;
2081         int avail_len = buffer_len;
2082         char *cp0 = head->write_buf;
2083
2084         if (!head->write)
2085                 return -ENOSYS;
2086         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2087                 return -EFAULT;
2088         /* Don't allow updating policies by non manager programs. */
2089         if (head->write != tomoyo_write_pid &&
2090             head->write != tomoyo_write_domain_policy &&
2091             !tomoyo_is_policy_manager())
2092                 return -EPERM;
2093         if (mutex_lock_interruptible(&head->io_sem))
2094                 return -EINTR;
2095         /* Read a line and dispatch it to the policy handler. */
2096         while (avail_len > 0) {
2097                 char c;
2098                 if (head->write_avail >= head->writebuf_size - 1) {
2099                         error = -ENOMEM;
2100                         break;
2101                 } else if (get_user(c, buffer)) {
2102                         error = -EFAULT;
2103                         break;
2104                 }
2105                 buffer++;
2106                 avail_len--;
2107                 cp0[head->write_avail++] = c;
2108                 if (c != '\n')
2109                         continue;
2110                 cp0[head->write_avail - 1] = '\0';
2111                 head->write_avail = 0;
2112                 tomoyo_normalize_line(cp0);
2113                 head->write(head);
2114         }
2115         mutex_unlock(&head->io_sem);
2116         return error;
2117 }
2118
2119 /**
2120  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2121  *
2122  * @file: Pointer to "struct file".
2123  *
2124  * Releases memory and returns 0.
2125  *
2126  * Caller looses tomoyo_read_lock().
2127  */
2128 static int tomoyo_close_control(struct file *file)
2129 {
2130         struct tomoyo_io_buffer *head = file->private_data;
2131
2132         tomoyo_read_unlock(head->reader_idx);
2133         /* Release memory used for policy I/O. */
2134         kfree(head->read_buf);
2135         head->read_buf = NULL;
2136         kfree(head->write_buf);
2137         head->write_buf = NULL;
2138         kfree(head);
2139         head = NULL;
2140         file->private_data = NULL;
2141         return 0;
2142 }
2143
2144 /**
2145  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2146  *
2147  * @inode: Pointer to "struct inode".
2148  * @file:  Pointer to "struct file".
2149  *
2150  * Returns 0 on success, negative value otherwise.
2151  */
2152 static int tomoyo_open(struct inode *inode, struct file *file)
2153 {
2154         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2155                 - ((u8 *) NULL);
2156         return tomoyo_open_control(key, file);
2157 }
2158
2159 /**
2160  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2161  *
2162  * @inode: Pointer to "struct inode".
2163  * @file:  Pointer to "struct file".
2164  *
2165  * Returns 0 on success, negative value otherwise.
2166  */
2167 static int tomoyo_release(struct inode *inode, struct file *file)
2168 {
2169         return tomoyo_close_control(file);
2170 }
2171
2172 /**
2173  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2174  *
2175  * @file:  Pointer to "struct file".
2176  * @buf:   Pointer to buffer.
2177  * @count: Size of @buf.
2178  * @ppos:  Unused.
2179  *
2180  * Returns bytes read on success, negative value otherwise.
2181  */
2182 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2183                            loff_t *ppos)
2184 {
2185         return tomoyo_read_control(file, buf, count);
2186 }
2187
2188 /**
2189  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2190  *
2191  * @file:  Pointer to "struct file".
2192  * @buf:   Pointer to buffer.
2193  * @count: Size of @buf.
2194  * @ppos:  Unused.
2195  *
2196  * Returns @count on success, negative value otherwise.
2197  */
2198 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2199                             size_t count, loff_t *ppos)
2200 {
2201         return tomoyo_write_control(file, buf, count);
2202 }
2203
2204 /*
2205  * tomoyo_operations is a "struct file_operations" which is used for handling
2206  * /sys/kernel/security/tomoyo/ interface.
2207  *
2208  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2209  * See tomoyo_io_buffer for internals.
2210  */
2211 static const struct file_operations tomoyo_operations = {
2212         .open    = tomoyo_open,
2213         .release = tomoyo_release,
2214         .read    = tomoyo_read,
2215         .write   = tomoyo_write,
2216 };
2217
2218 /**
2219  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2220  *
2221  * @name:   The name of the interface file.
2222  * @mode:   The permission of the interface file.
2223  * @parent: The parent directory.
2224  * @key:    Type of interface.
2225  *
2226  * Returns nothing.
2227  */
2228 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2229                                        struct dentry *parent, const u8 key)
2230 {
2231         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2232                                &tomoyo_operations);
2233 }
2234
2235 /**
2236  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2237  *
2238  * Returns 0.
2239  */
2240 static int __init tomoyo_initerface_init(void)
2241 {
2242         struct dentry *tomoyo_dir;
2243
2244         /* Don't create securityfs entries unless registered. */
2245         if (current_cred()->security != &tomoyo_kernel_domain)
2246                 return 0;
2247
2248         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2249         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2250                             TOMOYO_DOMAINPOLICY);
2251         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2252                             TOMOYO_EXCEPTIONPOLICY);
2253         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2254                             TOMOYO_SELFDOMAIN);
2255         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2256                             TOMOYO_DOMAIN_STATUS);
2257         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2258                             TOMOYO_PROCESS_STATUS);
2259         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2260                             TOMOYO_MEMINFO);
2261         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2262                             TOMOYO_PROFILE);
2263         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2264                             TOMOYO_MANAGER);
2265         tomoyo_create_entry("version",          0400, tomoyo_dir,
2266                             TOMOYO_VERSION);
2267         return 0;
2268 }
2269
2270 fs_initcall(tomoyo_initerface_init);