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_parse_name_union - Parse a tomoyo_name_union.
  80  *
  81  * @filename: Name or name group.
  82  * @ptr:      Pointer to "struct tomoyo_name_union".
  83  *
  84  * Returns true on success, false otherwise.
  85  */
  86 bool tomoyo_parse_name_union(const char *filename,
  87                              struct tomoyo_name_union *ptr)
  88 {
  89         if (!tomoyo_is_correct_path(filename, 0, 0, 0))
  90                 return false;
  91         if (filename[0] == '@') {
  92                 ptr->group = tomoyo_get_path_group(filename + 1);
  93                 ptr->is_group = true;
  94                 return ptr->group != NULL;
  95         }
  96         ptr->filename = tomoyo_get_name(filename);
  97         ptr->is_group = false;
  98         return ptr->filename != NULL;
  99 }
 100
 101 /**
 102  * tomoyo_print_name_union - Print a tomoyo_name_union.
 103  *
 104  * @head: Pointer to "struct tomoyo_io_buffer".
 105  * @ptr:  Pointer to "struct tomoyo_name_union".
 106  *
 107  * Returns true on success, false otherwise.
 108  */
 109 static bool tomoyo_print_name_union(struct tomoyo_io_buffer *head,
 110                                  const struct tomoyo_name_union *ptr)
 111 {
 112         int pos = head->read_avail;
 113         if (pos && head->read_buf[pos - 1] == ' ')
 114                 head->read_avail--;
 115         if (ptr->is_group)
 116                 return tomoyo_io_printf(head, " @%s",
 117                                         ptr->group->group_name->name);
 118         return tomoyo_io_printf(head, " %s", ptr->filename->name);
 119 }
 120
 121 /**
 122  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
 123  *
 124  * @str: Pointer to the string.
 125  *
 126  * Returns true if @str is a \ooo style octal value, false otherwise.
 127  *
 128  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
 129  * This function verifies that \ooo is in valid range.
 130  */
 131 static inline bool tomoyo_is_byte_range(const char *str)
 132 {
 133         return *str >= '0' && *str++ <= '3' &&
 134                 *str >= '0' && *str++ <= '7' &&
 135                 *str >= '0' && *str <= '7';
 136 }
 137
 138 /**
 139  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
 140  *
 141  * @c: The character to check.
 142  *
 143  * Returns true if @c is an alphabet character, false otherwise.
 144  */
 145 static inline bool tomoyo_is_alphabet_char(const char c)
 146 {
 147         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 148 }
 149
 150 /**
 151  * tomoyo_make_byte - Make byte value from three octal characters.
 152  *
 153  * @c1: The first character.
 154  * @c2: The second character.
 155  * @c3: The third character.
 156  *
 157  * Returns byte value.
 158  */
 159 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 160 {
 161         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 162 }
 163
 164 /**
 165  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 166  *
 167  * @src:  Pointer to pointer to the string.
 168  * @find: Pointer to the keyword.
 169  *
 170  * Returns true if @src starts with @find, false otherwise.
 171  *
 172  * The @src is updated to point the first character after the @find
 173  * if @src starts with @find.
 174  */
 175 static bool tomoyo_str_starts(char **src, const char *find)
 176 {
 177         const int len = strlen(find);
 178         char *tmp = *src;
 179
 180         if (strncmp(tmp, find, len))
 181                 return false;
 182         tmp += len;
 183         *src = tmp;
 184         return true;
 185 }
 186
 187 /**
 188  * tomoyo_normalize_line - Format string.
 189  *
 190  * @buffer: The line to normalize.
 191  *
 192  * Leading and trailing whitespaces are removed.
 193  * Multiple whitespaces are packed into single space.
 194  *
 195  * Returns nothing.
 196  */
 197 static void tomoyo_normalize_line(unsigned char *buffer)
 198 {
 199         unsigned char *sp = buffer;
 200         unsigned char *dp = buffer;
 201         bool first = true;
 202
 203         while (tomoyo_is_invalid(*sp))
 204                 sp++;
 205         while (*sp) {
 206                 if (!first)
 207                         *dp++ = ' ';
 208                 first = false;
 209                 while (tomoyo_is_valid(*sp))
 210                         *dp++ = *sp++;
 211                 while (tomoyo_is_invalid(*sp))
 212                         sp++;
 213         }
 214         *dp = '\0';
 215 }
 216
 217 /**
 218  * tomoyo_tokenize - Tokenize string.
 219  *
 220  * @buffer: The line to tokenize.
 221  * @w:      Pointer to "char *".
 222  * @size:   Sizeof @w .
 223  *
 224  * Returns true on success, false otherwise.
 225  */
 226 bool tomoyo_tokenize(char *buffer, char *w[], size_t size)
 227 {
 228         int count = size / sizeof(char *);
 229         int i;
 230         for (i = 0; i < count; i++)
 231                 w[i] = "";
 232         for (i = 0; i < count; i++) {
 233                 char *cp = strchr(buffer, ' ');
 234                 if (cp)
 235                         *cp = '\0';
 236                 w[i] = buffer;
 237                 if (!cp)
 238                         break;
 239                 buffer = cp + 1;
 240         }
 241         return i < count || !*buffer;
 242 }
 243
 244 /**
 245  * tomoyo_is_correct_path - Validate a pathname.
 246  * @filename:     The pathname to check.
 247  * @start_type:   Should the pathname start with '/'?
 248  *                1 = must / -1 = must not / 0 = don't care
 249  * @pattern_type: Can the pathname contain a wildcard?
 250  *                1 = must / -1 = must not / 0 = don't care
 251  * @end_type:     Should the pathname end with '/'?
 252  *                1 = must / -1 = must not / 0 = don't care
 253  *
 254  * Check whether the given filename follows the naming rules.
 255  * Returns true if @filename follows the naming rules, false otherwise.
 256  */
 257 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 258                             const s8 pattern_type, const s8 end_type)
 259 {
 260         const char *const start = filename;
 261         bool in_repetition = false;
 262         bool contains_pattern = false;
 263         unsigned char c;
 264         unsigned char d;
 265         unsigned char e;
 266
 267         if (!filename)
 268                 goto out;
 269         c = *filename;
 270         if (start_type == 1) { /* Must start with '/' */
 271                 if (c != '/')
 272                         goto out;
 273         } else if (start_type == -1) { /* Must not start with '/' */
 274                 if (c == '/')
 275                         goto out;
 276         }
 277         if (c)
 278                 c = *(filename + strlen(filename) - 1);
 279         if (end_type == 1) { /* Must end with '/' */
 280                 if (c != '/')
 281                         goto out;
 282         } else if (end_type == -1) { /* Must not end with '/' */
 283                 if (c == '/')
 284                         goto out;
 285         }
 286         while (1) {
 287                 c = *filename++;
 288                 if (!c)
 289                         break;
 290                 if (c == '\\') {
 291                         c = *filename++;
 292                         switch (c) {
 293                         case '\\':  /* "\\" */
 294                                 continue;
 295                         case '$':   /* "\$" */
 296                         case '+':   /* "\+" */
 297                         case '?':   /* "\?" */
 298                         case '*':   /* "\*" */
 299                         case '@':   /* "\@" */
 300                         case 'x':   /* "\x" */
 301                         case 'X':   /* "\X" */
 302                         case 'a':   /* "\a" */
 303                         case 'A':   /* "\A" */
 304                         case '-':   /* "\-" */
 305                                 if (pattern_type == -1)
 306                                         break; /* Must not contain pattern */
 307                                 contains_pattern = true;
 308                                 continue;
 309                         case '{':   /* "/\{" */
 310                                 if (filename - 3 < start ||
 311                                     *(filename - 3) != '/')
 312                                         break;
 313                                 if (pattern_type == -1)
 314                                         break; /* Must not contain pattern */
 315                                 contains_pattern = true;
 316                                 in_repetition = true;
 317                                 continue;
 318                         case '}':   /* "\}/" */
 319                                 if (*filename != '/')
 320                                         break;
 321                                 if (!in_repetition)
 322                                         break;
 323                                 in_repetition = false;
 324                                 continue;
 325                         case '0':   /* "\ooo" */
 326                         case '1':
 327                         case '2':
 328                         case '3':
 329                                 d = *filename++;
 330                                 if (d < '0' || d > '7')
 331                                         break;
 332                                 e = *filename++;
 333                                 if (e < '0' || e > '7')
 334                                         break;
 335                                 c = tomoyo_make_byte(c, d, e);
 336                                 if (tomoyo_is_invalid(c))
 337                                         continue; /* pattern is not \000 */
 338                         }
 339                         goto out;
 340                 } else if (in_repetition && c == '/') {
 341                         goto out;
 342                 } else if (tomoyo_is_invalid(c)) {
 343                         goto out;
 344                 }
 345         }
 346         if (pattern_type == 1) { /* Must contain pattern */
 347                 if (!contains_pattern)
 348                         goto out;
 349         }
 350         if (in_repetition)
 351                 goto out;
 352         return true;
 353  out:
 354         return false;
 355 }
 356
 357 /**
 358  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 359  * @domainname:   The domainname to check.
 360  *
 361  * Returns true if @domainname follows the naming rules, false otherwise.
 362  */
 363 bool tomoyo_is_correct_domain(const unsigned char *domainname)
 364 {
 365         unsigned char c;
 366         unsigned char d;
 367         unsigned char e;
 368
 369         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 370                                    TOMOYO_ROOT_NAME_LEN))
 371                 goto out;
 372         domainname += TOMOYO_ROOT_NAME_LEN;
 373         if (!*domainname)
 374                 return true;
 375         do {
 376                 if (*domainname++ != ' ')
 377                         goto out;
 378                 if (*domainname++ != '/')
 379                         goto out;
 380                 while ((c = *domainname) != '\0' && c != ' ') {
 381                         domainname++;
 382                         if (c == '\\') {
 383                                 c = *domainname++;
 384                                 switch ((c)) {
 385                                 case '\\':  /* "\\" */
 386                                         continue;
 387                                 case '0':   /* "\ooo" */
 388                                 case '1':
 389                                 case '2':
 390                                 case '3':
 391                                         d = *domainname++;
 392                                         if (d < '0' || d > '7')
 393                                                 break;
 394                                         e = *domainname++;
 395                                         if (e < '0' || e > '7')
 396                                                 break;
 397                                         c = tomoyo_make_byte(c, d, e);
 398                                         if (tomoyo_is_invalid(c))
 399                                                 /* pattern is not \000 */
 400                                                 continue;
 401                                 }
 402                                 goto out;
 403                         } else if (tomoyo_is_invalid(c)) {
 404                                 goto out;
 405                         }
 406                 }
 407         } while (*domainname);
 408         return true;
 409  out:
 410         return false;
 411 }
 412
 413 /**
 414  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 415  *
 416  * @buffer: The token to check.
 417  *
 418  * Returns true if @buffer possibly be a domainname, false otherwise.
 419  */
 420 bool tomoyo_is_domain_def(const unsigned char *buffer)
 421 {
 422         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 423 }
 424
 425 /**
 426  * tomoyo_find_domain - Find a domain by the given name.
 427  *
 428  * @domainname: The domainname to find.
 429  *
 430  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 431  *
 432  * Caller holds tomoyo_read_lock().
 433  */
 434 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 435 {
 436         struct tomoyo_domain_info *domain;
 437         struct tomoyo_path_info name;
 438
 439         name.name = domainname;
 440         tomoyo_fill_path_info(&name);
 441         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
 442                 if (!domain->is_deleted &&
 443                     !tomoyo_pathcmp(&name, domain->domainname))
 444                         return domain;
 445         }
 446         return NULL;
 447 }
 448
 449 /**
 450  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 451  *
 452  * @filename: The string to evaluate.
 453  *
 454  * Returns the initial length without a pattern in @filename.
 455  */
 456 static int tomoyo_const_part_length(const char *filename)
 457 {
 458         char c;
 459         int len = 0;
 460
 461         if (!filename)
 462                 return 0;
 463         while ((c = *filename++) != '\0') {
 464                 if (c != '\\') {
 465                         len++;
 466                         continue;
 467                 }
 468                 c = *filename++;
 469                 switch (c) {
 470                 case '\\':  /* "\\" */
 471                         len += 2;
 472                         continue;
 473                 case '0':   /* "\ooo" */
 474                 case '1':
 475                 case '2':
 476                 case '3':
 477                         c = *filename++;
 478                         if (c < '0' || c > '7')
 479                                 break;
 480                         c = *filename++;
 481                         if (c < '0' || c > '7')
 482                                 break;
 483                         len += 4;
 484                         continue;
 485                 }
 486                 break;
 487         }
 488         return len;
 489 }
 490
 491 /**
 492  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 493  *
 494  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 495  *
 496  * The caller sets "struct tomoyo_path_info"->name.
 497  */
 498 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 499 {
 500         const char *name = ptr->name;
 501         const int len = strlen(name);
 502
 503         ptr->const_len = tomoyo_const_part_length(name);
 504         ptr->is_dir = len && (name[len - 1] == '/');
 505         ptr->is_patterned = (ptr->const_len < len);
 506         ptr->hash = full_name_hash(name, len);
 507 }
 508
 509 /**
 510  * tomoyo_file_matches_pattern2 - Pattern matching without '/' character
 511  * and "\-" pattern.
 512  *
 513  * @filename:     The start of string to check.
 514  * @filename_end: The end of string to check.
 515  * @pattern:      The start of pattern to compare.
 516  * @pattern_end:  The end of pattern to compare.
 517  *
 518  * Returns true if @filename matches @pattern, false otherwise.
 519  */
 520 static bool tomoyo_file_matches_pattern2(const char *filename,
 521                                          const char *filename_end,
 522                                          const char *pattern,
 523                                          const char *pattern_end)
 524 {
 525         while (filename < filename_end && pattern < pattern_end) {
 526                 char c;
 527                 if (*pattern != '\\') {
 528                         if (*filename++ != *pattern++)
 529                                 return false;
 530                         continue;
 531                 }
 532                 c = *filename;
 533                 pattern++;
 534                 switch (*pattern) {
 535                         int i;
 536                         int j;
 537                 case '?':
 538                         if (c == '/') {
 539                                 return false;
 540                         } else if (c == '\\') {
 541                                 if (filename[1] == '\\')
 542                                         filename++;
 543                                 else if (tomoyo_is_byte_range(filename + 1))
 544                                         filename += 3;
 545                                 else
 546                                         return false;
 547                         }
 548                         break;
 549                 case '\\':
 550                         if (c != '\\')
 551                                 return false;
 552                         if (*++filename != '\\')
 553                                 return false;
 554                         break;
 555                 case '+':
 556                         if (!isdigit(c))
 557                                 return false;
 558                         break;
 559                 case 'x':
 560                         if (!isxdigit(c))
 561                                 return false;
 562                         break;
 563                 case 'a':
 564                         if (!tomoyo_is_alphabet_char(c))
 565                                 return false;
 566                         break;
 567                 case '0':
 568                 case '1':
 569                 case '2':
 570                 case '3':
 571                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 572                             && strncmp(filename + 1, pattern, 3) == 0) {
 573                                 filename += 3;
 574                                 pattern += 2;
 575                                 break;
 576                         }
 577                         return false; /* Not matched. */
 578                 case '*':
 579                 case '@':
 580                         for (i = 0; i <= filename_end - filename; i++) {
 581                                 if (tomoyo_file_matches_pattern2(
 582                                                     filename + i, filename_end,
 583                                                     pattern + 1, pattern_end))
 584                                         return true;
 585                                 c = filename[i];
 586                                 if (c == '.' && *pattern == '@')
 587                                         break;
 588                                 if (c != '\\')
 589                                         continue;
 590                                 if (filename[i + 1] == '\\')
 591                                         i++;
 592                                 else if (tomoyo_is_byte_range(filename + i + 1))
 593                                         i += 3;
 594                                 else
 595                                         break; /* Bad pattern. */
 596                         }
 597                         return false; /* Not matched. */
 598                 default:
 599                         j = 0;
 600                         c = *pattern;
 601                         if (c == '$') {
 602                                 while (isdigit(filename[j]))
 603                                         j++;
 604                         } else if (c == 'X') {
 605                                 while (isxdigit(filename[j]))
 606                                         j++;
 607                         } else if (c == 'A') {
 608                                 while (tomoyo_is_alphabet_char(filename[j]))
 609                                         j++;
 610                         }
 611                         for (i = 1; i <= j; i++) {
 612                                 if (tomoyo_file_matches_pattern2(
 613                                                     filename + i, filename_end,
 614                                                     pattern + 1, pattern_end))
 615                                         return true;
 616                         }
 617                         return false; /* Not matched or bad pattern. */
 618                 }
 619                 filename++;
 620                 pattern++;
 621         }
 622         while (*pattern == '\\' &&
 623                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 624                 pattern += 2;
 625         return filename == filename_end && pattern == pattern_end;
 626 }
 627
 628 /**
 629  * tomoyo_file_matches_pattern - Pattern matching without without '/' character.
 630  *
 631  * @filename:     The start of string to check.
 632  * @filename_end: The end of string to check.
 633  * @pattern:      The start of pattern to compare.
 634  * @pattern_end:  The end of pattern to compare.
 635  *
 636  * Returns true if @filename matches @pattern, false otherwise.
 637  */
 638 static bool tomoyo_file_matches_pattern(const char *filename,
 639                                            const char *filename_end,
 640                                            const char *pattern,
 641                                            const char *pattern_end)
 642 {
 643         const char *pattern_start = pattern;
 644         bool first = true;
 645         bool result;
 646
 647         while (pattern < pattern_end - 1) {
 648                 /* Split at "\-" pattern. */
 649                 if (*pattern++ != '\\' || *pattern++ != '-')
 650                         continue;
 651                 result = tomoyo_file_matches_pattern2(filename,
 652                                                       filename_end,
 653                                                       pattern_start,
 654                                                       pattern - 2);
 655                 if (first)
 656                         result = !result;
 657                 if (result)
 658                         return false;
 659                 first = false;
 660                 pattern_start = pattern;
 661         }
 662         result = tomoyo_file_matches_pattern2(filename, filename_end,
 663                                               pattern_start, pattern_end);
 664         return first ? result : !result;
 665 }
 666
 667 /**
 668  * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
 669  *
 670  * @f: The start of string to check.
 671  * @p: The start of pattern to compare.
 672  *
 673  * Returns true if @f matches @p, false otherwise.
 674  */
 675 static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
 676 {
 677         const char *f_delimiter;
 678         const char *p_delimiter;
 679
 680         while (*f && *p) {
 681                 f_delimiter = strchr(f, '/');
 682                 if (!f_delimiter)
 683                         f_delimiter = f + strlen(f);
 684                 p_delimiter = strchr(p, '/');
 685                 if (!p_delimiter)
 686                         p_delimiter = p + strlen(p);
 687                 if (*p == '\\' && *(p + 1) == '{')
 688                         goto recursive;
 689                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
 690                                                  p_delimiter))
 691                         return false;
 692                 f = f_delimiter;
 693                 if (*f)
 694                         f++;
 695                 p = p_delimiter;
 696                 if (*p)
 697                         p++;
 698         }
 699         /* Ignore trailing "\*" and "\@" in @pattern. */
 700         while (*p == '\\' &&
 701                (*(p + 1) == '*' || *(p + 1) == '@'))
 702                 p += 2;
 703         return !*f && !*p;
 704  recursive:
 705         /*
 706          * The "\{" pattern is permitted only after '/' character.
 707          * This guarantees that below "*(p - 1)" is safe.
 708          * Also, the "\}" pattern is permitted only before '/' character
 709          * so that "\{" + "\}" pair will not break the "\-" operator.
 710          */
 711         if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
 712             *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
 713                 return false; /* Bad pattern. */
 714         do {
 715                 /* Compare current component with pattern. */
 716                 if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
 717                                                  p_delimiter - 2))
 718                         break;
 719                 /* Proceed to next component. */
 720                 f = f_delimiter;
 721                 if (!*f)
 722                         break;
 723                 f++;
 724                 /* Continue comparison. */
 725                 if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
 726                         return true;
 727                 f_delimiter = strchr(f, '/');
 728         } while (f_delimiter);
 729         return false; /* Not matched. */
 730 }
 731
 732 /**
 733  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 734  *
 735  * @filename: The filename to check.
 736  * @pattern:  The pattern to compare.
 737  *
 738  * Returns true if matches, false otherwise.
 739  *
 740  * The following patterns are available.
 741  *   \\     \ itself.
 742  *   \ooo   Octal representation of a byte.
 743  *   \*     Zero or more repetitions of characters other than '/'.
 744  *   \@     Zero or more repetitions of characters other than '/' or '.'.
 745  *   \?     1 byte character other than '/'.
 746  *   \$     One or more repetitions of decimal digits.
 747  *   \+     1 decimal digit.
 748  *   \X     One or more repetitions of hexadecimal digits.
 749  *   \x     1 hexadecimal digit.
 750  *   \A     One or more repetitions of alphabet characters.
 751  *   \a     1 alphabet character.
 752  *
 753  *   \-     Subtraction operator.
 754  *
 755  *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
 756  *               /dir/dir/dir/ ).
 757  */
 758 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 759                                  const struct tomoyo_path_info *pattern)
 760 {
 761         const char *f = filename->name;
 762         const char *p = pattern->name;
 763         const int len = pattern->const_len;
 764
 765         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 766         if (!pattern->is_patterned)
 767                 return !tomoyo_pathcmp(filename, pattern);
 768         /* Don't compare directory and non-directory. */
 769         if (filename->is_dir != pattern->is_dir)
 770                 return false;
 771         /* Compare the initial length without patterns. */
 772         if (strncmp(f, p, len))
 773                 return false;
 774         f += len;
 775         p += len;
 776         return tomoyo_path_matches_pattern2(f, p);
 777 }
 778
 779 /**
 780  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 781  *
 782  * @head: Pointer to "struct tomoyo_io_buffer".
 783  * @fmt:  The printf()'s format string, followed by parameters.
 784  *
 785  * Returns true if output was written, false otherwise.
 786  *
 787  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 788  */
 789 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 790 {
 791         va_list args;
 792         int len;
 793         int pos = head->read_avail;
 794         int size = head->readbuf_size - pos;
 795
 796         if (size <= 0)
 797                 return false;
 798         va_start(args, fmt);
 799         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 800         va_end(args);
 801         if (pos + len >= head->readbuf_size)
 802                 return false;
 803         head->read_avail += len;
 804         return true;
 805 }
 806
 807 /**
 808  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 809  *
 810  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 811  *
 812  * This function uses kzalloc(), so the caller must call kfree()
 813  * if this function didn't return NULL.
 814  */
 815 static const char *tomoyo_get_exe(void)
 816 {
 817         struct mm_struct *mm = current->mm;
 818         struct vm_area_struct *vma;
 819         const char *cp = NULL;
 820
 821         if (!mm)
 822                 return NULL;
 823         down_read(&mm->mmap_sem);
 824         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 825                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 826                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 827                         break;
 828                 }
 829         }
 830         up_read(&mm->mmap_sem);
 831         return cp;
 832 }
 833
 834 /**
 835  * tomoyo_get_msg - Get warning message.
 836  *
 837  * @is_enforce: Is it enforcing mode?
 838  *
 839  * Returns "ERROR" or "WARNING".
 840  */
 841 const char *tomoyo_get_msg(const bool is_enforce)
 842 {
 843         if (is_enforce)
 844                 return "ERROR";
 845         else
 846                 return "WARNING";
 847 }
 848
 849 /**
 850  * tomoyo_check_flags - Check mode for specified functionality.
 851  *
 852  * @domain: Pointer to "struct tomoyo_domain_info".
 853  * @index:  The functionality to check mode.
 854  *
 855  * TOMOYO checks only process context.
 856  * This code disables TOMOYO's enforcement in case the function is called from
 857  * interrupt context.
 858  */
 859 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 860                                 const u8 index)
 861 {
 862         const u8 profile = domain->profile;
 863
 864         if (WARN_ON(in_interrupt()))
 865                 return 0;
 866         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 867 #if TOMOYO_MAX_PROFILES != 256
 868                 && profile < TOMOYO_MAX_PROFILES
 869 #endif
 870                 && tomoyo_profile_ptr[profile] ?
 871                 tomoyo_profile_ptr[profile]->value[index] : 0;
 872 }
 873
 874 /**
 875  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 876  *
 877  * @domain: Pointer to "struct tomoyo_domain_info".
 878  *
 879  * Returns true if domain policy violation warning should be printed to
 880  * console.
 881  */
 882 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 883 {
 884         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 885 }
 886
 887 /**
 888  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 889  *
 890  * @domain: Pointer to "struct tomoyo_domain_info".
 891  *
 892  * Returns true if the domain is not exceeded quota, false otherwise.
 893  *
 894  * Caller holds tomoyo_read_lock().
 895  */
 896 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 897 {
 898         unsigned int count = 0;
 899         struct tomoyo_acl_info *ptr;
 900
 901         if (!domain)
 902                 return true;
 903         list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {
 904                 switch (ptr->type) {
 905                         struct tomoyo_path_acl *acl;
 906                         u32 perm;
 907                         u8 i;
 908                 case TOMOYO_TYPE_PATH_ACL:
 909                         acl = container_of(ptr, struct tomoyo_path_acl, head);
 910                         perm = acl->perm | (((u32) acl->perm_high) << 16);
 911                         for (i = 0; i < TOMOYO_MAX_PATH_OPERATION; i++)
 912                                 if (perm & (1 << i))
 913                                         count++;
 914                         if (perm & (1 << TOMOYO_TYPE_READ_WRITE))
 915                                 count -= 2;
 916                         break;
 917                 case TOMOYO_TYPE_PATH2_ACL:
 918                         perm = container_of(ptr, struct tomoyo_path2_acl, head)
 919                                 ->perm;
 920                         for (i = 0; i < TOMOYO_MAX_PATH2_OPERATION; i++)
 921                                 if (perm & (1 << i))
 922                                         count++;
 923                         break;
 924                 }
 925         }
 926         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 927                 return true;
 928         if (!domain->quota_warned) {
 929                 domain->quota_warned = true;
 930                 printk(KERN_WARNING "TOMOYO-WARNING: "
 931                        "Domain '%s' has so many ACLs to hold. "
 932                        "Stopped learning mode.\n", domain->domainname->name);
 933         }
 934         return false;
 935 }
 936
 937 /**
 938  * tomoyo_find_or_assign_new_profile - Create a new profile.
 939  *
 940  * @profile: Profile number to create.
 941  *
 942  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 943  */
 944 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 945                                                                 int profile)
 946 {
 947         struct tomoyo_profile *ptr = NULL;
 948         int i;
 949
 950         if (profile >= TOMOYO_MAX_PROFILES)
 951                 return NULL;
 952         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 953                 return NULL;
 954         ptr = tomoyo_profile_ptr[profile];
 955         if (ptr)
 956                 goto ok;
 957         ptr = kmalloc(sizeof(*ptr), GFP_NOFS);
 958         if (!tomoyo_memory_ok(ptr)) {
 959                 kfree(ptr);
 960                 ptr = NULL;
 961                 goto ok;
 962         }
 963         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 964                 ptr->value[i] = tomoyo_control_array[i].current_value;
 965         mb(); /* Avoid out-of-order execution. */
 966         tomoyo_profile_ptr[profile] = ptr;
 967  ok:
 968         mutex_unlock(&tomoyo_policy_lock);
 969         return ptr;
 970 }
 971
 972 /**
 973  * tomoyo_write_profile - Write to profile table.
 974  *
 975  * @head: Pointer to "struct tomoyo_io_buffer".
 976  *
 977  * Returns 0 on success, negative value otherwise.
 978  */
 979 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 980 {
 981         char *data = head->write_buf;
 982         unsigned int i;
 983         unsigned int value;
 984         char *cp;
 985         struct tomoyo_profile *profile;
 986         unsigned long num;
 987
 988         cp = strchr(data, '-');
 989         if (cp)
 990                 *cp = '\0';
 991         if (strict_strtoul(data, 10, &num))
 992                 return -EINVAL;
 993         if (cp)
 994                 data = cp + 1;
 995         profile = tomoyo_find_or_assign_new_profile(num);
 996         if (!profile)
 997                 return -EINVAL;
 998         cp = strchr(data, '=');
 999         if (!cp)
1000                 return -EINVAL;
1001         *cp = '\0';
1002         if (!strcmp(data, "COMMENT")) {
1003                 const struct tomoyo_path_info *old_comment = profile->comment;
1004                 profile->comment = tomoyo_get_name(cp + 1);
1005                 tomoyo_put_name(old_comment);
1006                 return 0;
1007         }
1008         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
1009                 if (strcmp(data, tomoyo_control_array[i].keyword))
1010                         continue;
1011                 if (sscanf(cp + 1, "%u", &value) != 1) {
1012                         int j;
1013                         const char **modes;
1014                         switch (i) {
1015                         case TOMOYO_VERBOSE:
1016                                 modes = tomoyo_mode_2;
1017                                 break;
1018                         default:
1019                                 modes = tomoyo_mode_4;
1020                                 break;
1021                         }
1022                         for (j = 0; j < 4; j++) {
1023                                 if (strcmp(cp + 1, modes[j]))
1024                                         continue;
1025                                 value = j;
1026                                 break;
1027                         }
1028                         if (j == 4)
1029                                 return -EINVAL;
1030                 } else if (value > tomoyo_control_array[i].max_value) {
1031                         value = tomoyo_control_array[i].max_value;
1032                 }
1033                 profile->value[i] = value;
1034                 return 0;
1035         }
1036         return -EINVAL;
1037 }
1038
1039 /**
1040  * tomoyo_read_profile - Read from profile table.
1041  *
1042  * @head: Pointer to "struct tomoyo_io_buffer".
1043  *
1044  * Returns 0.
1045  */
1046 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
1047 {
1048         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
1049         int step;
1050
1051         if (head->read_eof)
1052                 return 0;
1053         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
1054              step++) {
1055                 const u8 index = step / total;
1056                 u8 type = step % total;
1057                 const struct tomoyo_profile *profile
1058                         = tomoyo_profile_ptr[index];
1059                 head->read_step = step;
1060                 if (!profile)
1061                         continue;
1062                 if (!type) { /* Print profile' comment tag. */
1063                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
1064                                               index, profile->comment ?
1065                                               profile->comment->name : ""))
1066                                 break;
1067                         continue;
1068                 }
1069                 type--;
1070                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
1071                         const unsigned int value = profile->value[type];
1072                         const char **modes = NULL;
1073                         const char *keyword
1074                                 = tomoyo_control_array[type].keyword;
1075                         switch (tomoyo_control_array[type].max_value) {
1076                         case 3:
1077                                 modes = tomoyo_mode_4;
1078                                 break;
1079                         case 1:
1080                                 modes = tomoyo_mode_2;
1081                                 break;
1082                         }
1083                         if (modes) {
1084                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1085                                                       keyword, modes[value]))
1086                                         break;
1087                         } else {
1088                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1089                                                       keyword, value))
1090                                         break;
1091                         }
1092                 }
1093         }
1094         if (step == TOMOYO_MAX_PROFILES * total)
1095                 head->read_eof = true;
1096         return 0;
1097 }
1098
1099 /*
1100  * tomoyo_policy_manager_list is used for holding list of domainnames or
1101  * programs which are permitted to modify configuration via
1102  * /sys/kernel/security/tomoyo/ interface.
1103  *
1104  * An entry is added by
1105  *
1106  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1107  *                                        /sys/kernel/security/tomoyo/manager
1108  *  (if you want to specify by a domainname)
1109  *
1110  *  or
1111  *
1112  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1113  *  (if you want to specify by a program's location)
1114  *
1115  * and is deleted by
1116  *
1117  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1118  *                                        /sys/kernel/security/tomoyo/manager
1119  *
1120  *  or
1121  *
1122  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1123  *                                        /sys/kernel/security/tomoyo/manager
1124  *
1125  * and all entries are retrieved by
1126  *
1127  * # cat /sys/kernel/security/tomoyo/manager
1128  */
1129 LIST_HEAD(tomoyo_policy_manager_list);
1130
1131 /**
1132  * tomoyo_update_manager_entry - Add a manager entry.
1133  *
1134  * @manager:   The path to manager or the domainnamme.
1135  * @is_delete: True if it is a delete request.
1136  *
1137  * Returns 0 on success, negative value otherwise.
1138  *
1139  * Caller holds tomoyo_read_lock().
1140  */
1141 static int tomoyo_update_manager_entry(const char *manager,
1142                                        const bool is_delete)
1143 {
1144         struct tomoyo_policy_manager_entry *ptr;
1145         struct tomoyo_policy_manager_entry e = { };
1146         int error = is_delete ? -ENOENT : -ENOMEM;
1147
1148         if (tomoyo_is_domain_def(manager)) {
1149                 if (!tomoyo_is_correct_domain(manager))
1150                         return -EINVAL;
1151                 e.is_domain = true;
1152         } else {
1153                 if (!tomoyo_is_correct_path(manager, 1, -1, -1))
1154                         return -EINVAL;
1155         }
1156         e.manager = tomoyo_get_name(manager);
1157         if (!e.manager)
1158                 return -ENOMEM;
1159         if (mutex_lock_interruptible(&tomoyo_policy_lock))
1160                 goto out;
1161         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1162                 if (ptr->manager != e.manager)
1163                         continue;
1164                 ptr->is_deleted = is_delete;
1165                 error = 0;
1166                 break;
1167         }
1168         if (!is_delete && error) {
1169                 struct tomoyo_policy_manager_entry *entry =
1170                         tomoyo_commit_ok(&e, sizeof(e));
1171                 if (entry) {
1172                         list_add_tail_rcu(&entry->list,
1173                                           &tomoyo_policy_manager_list);
1174                         error = 0;
1175                 }
1176         }
1177         mutex_unlock(&tomoyo_policy_lock);
1178  out:
1179         tomoyo_put_name(e.manager);
1180         return error;
1181 }
1182
1183 /**
1184  * tomoyo_write_manager_policy - Write manager policy.
1185  *
1186  * @head: Pointer to "struct tomoyo_io_buffer".
1187  *
1188  * Returns 0 on success, negative value otherwise.
1189  *
1190  * Caller holds tomoyo_read_lock().
1191  */
1192 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1193 {
1194         char *data = head->write_buf;
1195         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1196
1197         if (!strcmp(data, "manage_by_non_root")) {
1198                 tomoyo_manage_by_non_root = !is_delete;
1199                 return 0;
1200         }
1201         return tomoyo_update_manager_entry(data, is_delete);
1202 }
1203
1204 /**
1205  * tomoyo_read_manager_policy - Read manager policy.
1206  *
1207  * @head: Pointer to "struct tomoyo_io_buffer".
1208  *
1209  * Returns 0.
1210  *
1211  * Caller holds tomoyo_read_lock().
1212  */
1213 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1214 {
1215         struct list_head *pos;
1216         bool done = true;
1217
1218         if (head->read_eof)
1219                 return 0;
1220         list_for_each_cookie(pos, head->read_var2,
1221                              &tomoyo_policy_manager_list) {
1222                 struct tomoyo_policy_manager_entry *ptr;
1223                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1224                                  list);
1225                 if (ptr->is_deleted)
1226                         continue;
1227                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1228                 if (!done)
1229                         break;
1230         }
1231         head->read_eof = done;
1232         return 0;
1233 }
1234
1235 /**
1236  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1237  *
1238  * Returns true if the current process is permitted to modify policy
1239  * via /sys/kernel/security/tomoyo/ interface.
1240  *
1241  * Caller holds tomoyo_read_lock().
1242  */
1243 static bool tomoyo_is_policy_manager(void)
1244 {
1245         struct tomoyo_policy_manager_entry *ptr;
1246         const char *exe;
1247         const struct task_struct *task = current;
1248         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1249         bool found = false;
1250
1251         if (!tomoyo_policy_loaded)
1252                 return true;
1253         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1254                 return false;
1255         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1256                 if (!ptr->is_deleted && ptr->is_domain
1257                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1258                         found = true;
1259                         break;
1260                 }
1261         }
1262         if (found)
1263                 return true;
1264         exe = tomoyo_get_exe();
1265         if (!exe)
1266                 return false;
1267         list_for_each_entry_rcu(ptr, &tomoyo_policy_manager_list, list) {
1268                 if (!ptr->is_deleted && !ptr->is_domain
1269                     && !strcmp(exe, ptr->manager->name)) {
1270                         found = true;
1271                         break;
1272                 }
1273         }
1274         if (!found) { /* Reduce error messages. */
1275                 static pid_t last_pid;
1276                 const pid_t pid = current->pid;
1277                 if (last_pid != pid) {
1278                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1279                                "update policies.\n", domainname->name, exe);
1280                         last_pid = pid;
1281                 }
1282         }
1283         kfree(exe);
1284         return found;
1285 }
1286
1287 /**
1288  * tomoyo_is_select_one - Parse select command.
1289  *
1290  * @head: Pointer to "struct tomoyo_io_buffer".
1291  * @data: String to parse.
1292  *
1293  * Returns true on success, false otherwise.
1294  *
1295  * Caller holds tomoyo_read_lock().
1296  */
1297 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1298                                  const char *data)
1299 {
1300         unsigned int pid;
1301         struct tomoyo_domain_info *domain = NULL;
1302
1303         if (sscanf(data, "pid=%u", &pid) == 1) {
1304                 struct task_struct *p;
1305                 rcu_read_lock();
1306                 read_lock(&tasklist_lock);
1307                 p = find_task_by_vpid(pid);
1308                 if (p)
1309                         domain = tomoyo_real_domain(p);
1310                 read_unlock(&tasklist_lock);
1311                 rcu_read_unlock();
1312         } else if (!strncmp(data, "domain=", 7)) {
1313                 if (tomoyo_is_domain_def(data + 7))
1314                         domain = tomoyo_find_domain(data + 7);
1315         } else
1316                 return false;
1317         head->write_var1 = domain;
1318         /* Accessing read_buf is safe because head->io_sem is held. */
1319         if (!head->read_buf)
1320                 return true; /* Do nothing if open(O_WRONLY). */
1321         head->read_avail = 0;
1322         tomoyo_io_printf(head, "# select %s\n", data);
1323         head->read_single_domain = true;
1324         head->read_eof = !domain;
1325         if (domain) {
1326                 struct tomoyo_domain_info *d;
1327                 head->read_var1 = NULL;
1328                 list_for_each_entry_rcu(d, &tomoyo_domain_list, list) {
1329                         if (d == domain)
1330                                 break;
1331                         head->read_var1 = &d->list;
1332                 }
1333                 head->read_var2 = NULL;
1334                 head->read_bit = 0;
1335                 head->read_step = 0;
1336                 if (domain->is_deleted)
1337                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1338         }
1339         return true;
1340 }
1341
1342 /**
1343  * tomoyo_delete_domain - Delete a domain.
1344  *
1345  * @domainname: The name of domain.
1346  *
1347  * Returns 0.
1348  *
1349  * Caller holds tomoyo_read_lock().
1350  */
1351 static int tomoyo_delete_domain(char *domainname)
1352 {
1353         struct tomoyo_domain_info *domain;
1354         struct tomoyo_path_info name;
1355
1356         name.name = domainname;
1357         tomoyo_fill_path_info(&name);
1358         if (mutex_lock_interruptible(&tomoyo_policy_lock))
1359                 return 0;
1360         /* Is there an active domain? */
1361         list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1362                 /* Never delete tomoyo_kernel_domain */
1363                 if (domain == &tomoyo_kernel_domain)
1364                         continue;
1365                 if (domain->is_deleted ||
1366                     tomoyo_pathcmp(domain->domainname, &name))
1367                         continue;
1368                 domain->is_deleted = true;
1369                 break;
1370         }
1371         mutex_unlock(&tomoyo_policy_lock);
1372         return 0;
1373 }
1374
1375 /**
1376  * tomoyo_write_domain_policy - Write domain policy.
1377  *
1378  * @head: Pointer to "struct tomoyo_io_buffer".
1379  *
1380  * Returns 0 on success, negative value otherwise.
1381  *
1382  * Caller holds tomoyo_read_lock().
1383  */
1384 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1385 {
1386         char *data = head->write_buf;
1387         struct tomoyo_domain_info *domain = head->write_var1;
1388         bool is_delete = false;
1389         bool is_select = false;
1390         unsigned int profile;
1391
1392         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1393                 is_delete = true;
1394         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1395                 is_select = true;
1396         if (is_select && tomoyo_is_select_one(head, data))
1397                 return 0;
1398         /* Don't allow updating policies by non manager programs. */
1399         if (!tomoyo_is_policy_manager())
1400                 return -EPERM;
1401         if (tomoyo_is_domain_def(data)) {
1402                 domain = NULL;
1403                 if (is_delete)
1404                         tomoyo_delete_domain(data);
1405                 else if (is_select)
1406                         domain = tomoyo_find_domain(data);
1407                 else
1408                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1409                 head->write_var1 = domain;
1410                 return 0;
1411         }
1412         if (!domain)
1413                 return -EINVAL;
1414
1415         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1416             && profile < TOMOYO_MAX_PROFILES) {
1417                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1418                         domain->profile = (u8) profile;
1419                 return 0;
1420         }
1421         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1422                 domain->ignore_global_allow_read = !is_delete;
1423                 return 0;
1424         }
1425         return tomoyo_write_file_policy(data, domain, is_delete);
1426 }
1427
1428 /**
1429  * tomoyo_print_path_acl - Print a single path ACL entry.
1430  *
1431  * @head: Pointer to "struct tomoyo_io_buffer".
1432  * @ptr:  Pointer to "struct tomoyo_path_acl".
1433  *
1434  * Returns true on success, false otherwise.
1435  */
1436 static bool tomoyo_print_path_acl(struct tomoyo_io_buffer *head,
1437                                   struct tomoyo_path_acl *ptr)
1438 {
1439         int pos;
1440         u8 bit;
1441         const u32 perm = ptr->perm | (((u32) ptr->perm_high) << 16);
1442
1443         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH_OPERATION; bit++) {
1444                 if (!(perm & (1 << bit)))
1445                         continue;
1446                 /* Print "read/write" instead of "read" and "write". */
1447                 if ((bit == TOMOYO_TYPE_READ || bit == TOMOYO_TYPE_WRITE)
1448                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE)))
1449                         continue;
1450                 pos = head->read_avail;
1451                 if (!tomoyo_io_printf(head, "allow_%s ",
1452                                       tomoyo_path2keyword(bit)) ||
1453                     !tomoyo_print_name_union(head, &ptr->name) ||
1454                     !tomoyo_io_printf(head, "\n"))
1455                         goto out;
1456         }
1457         head->read_bit = 0;
1458         return true;
1459  out:
1460         head->read_bit = bit;
1461         head->read_avail = pos;
1462         return false;
1463 }
1464
1465 /**
1466  * tomoyo_print_path2_acl - Print a double path ACL entry.
1467  *
1468  * @head: Pointer to "struct tomoyo_io_buffer".
1469  * @ptr:  Pointer to "struct tomoyo_path2_acl".
1470  *
1471  * Returns true on success, false otherwise.
1472  */
1473 static bool tomoyo_print_path2_acl(struct tomoyo_io_buffer *head,
1474                                    struct tomoyo_path2_acl *ptr)
1475 {
1476         int pos;
1477         const u8 perm = ptr->perm;
1478         u8 bit;
1479
1480         for (bit = head->read_bit; bit < TOMOYO_MAX_PATH2_OPERATION; bit++) {
1481                 if (!(perm & (1 << bit)))
1482                         continue;
1483                 pos = head->read_avail;
1484                 if (!tomoyo_io_printf(head, "allow_%s ",
1485                                       tomoyo_path22keyword(bit)) ||
1486                     !tomoyo_print_name_union(head, &ptr->name1) ||
1487                     !tomoyo_print_name_union(head, &ptr->name2) ||
1488                     !tomoyo_io_printf(head, "\n"))
1489                         goto out;
1490         }
1491         head->read_bit = 0;
1492         return true;
1493  out:
1494         head->read_bit = bit;
1495         head->read_avail = pos;
1496         return false;
1497 }
1498
1499 /**
1500  * tomoyo_print_entry - Print an ACL entry.
1501  *
1502  * @head: Pointer to "struct tomoyo_io_buffer".
1503  * @ptr:  Pointer to an ACL entry.
1504  *
1505  * Returns true on success, false otherwise.
1506  */
1507 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1508                                struct tomoyo_acl_info *ptr)
1509 {
1510         const u8 acl_type = ptr->type;
1511
1512         if (acl_type == TOMOYO_TYPE_PATH_ACL) {
1513                 struct tomoyo_path_acl *acl
1514                         = container_of(ptr, struct tomoyo_path_acl, head);
1515                 return tomoyo_print_path_acl(head, acl);
1516         }
1517         if (acl_type == TOMOYO_TYPE_PATH2_ACL) {
1518                 struct tomoyo_path2_acl *acl
1519                         = container_of(ptr, struct tomoyo_path2_acl, head);
1520                 return tomoyo_print_path2_acl(head, acl);
1521         }
1522         BUG(); /* This must not happen. */
1523         return false;
1524 }
1525
1526 /**
1527  * tomoyo_read_domain_policy - Read domain policy.
1528  *
1529  * @head: Pointer to "struct tomoyo_io_buffer".
1530  *
1531  * Returns 0.
1532  *
1533  * Caller holds tomoyo_read_lock().
1534  */
1535 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1536 {
1537         struct list_head *dpos;
1538         struct list_head *apos;
1539         bool done = true;
1540
1541         if (head->read_eof)
1542                 return 0;
1543         if (head->read_step == 0)
1544                 head->read_step = 1;
1545         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1546                 struct tomoyo_domain_info *domain;
1547                 const char *quota_exceeded = "";
1548                 const char *transition_failed = "";
1549                 const char *ignore_global_allow_read = "";
1550                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1551                 if (head->read_step != 1)
1552                         goto acl_loop;
1553                 if (domain->is_deleted && !head->read_single_domain)
1554                         continue;
1555                 /* Print domainname and flags. */
1556                 if (domain->quota_warned)
1557                         quota_exceeded = "quota_exceeded\n";
1558                 if (domain->transition_failed)
1559                         transition_failed = "transition_failed\n";
1560                 if (domain->ignore_global_allow_read)
1561                         ignore_global_allow_read
1562                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1563                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1564                                         "%u\n%s%s%s\n",
1565                                         domain->domainname->name,
1566                                         domain->profile, quota_exceeded,
1567                                         transition_failed,
1568                                         ignore_global_allow_read);
1569                 if (!done)
1570                         break;
1571                 head->read_step = 2;
1572 acl_loop:
1573                 if (head->read_step == 3)
1574                         goto tail_mark;
1575                 /* Print ACL entries in the domain. */
1576                 list_for_each_cookie(apos, head->read_var2,
1577                                      &domain->acl_info_list) {
1578                         struct tomoyo_acl_info *ptr
1579                                 = list_entry(apos, struct tomoyo_acl_info,
1580                                              list);
1581                         done = tomoyo_print_entry(head, ptr);
1582                         if (!done)
1583                                 break;
1584                 }
1585                 if (!done)
1586                         break;
1587                 head->read_step = 3;
1588 tail_mark:
1589                 done = tomoyo_io_printf(head, "\n");
1590                 if (!done)
1591                         break;
1592                 head->read_step = 1;
1593                 if (head->read_single_domain)
1594                         break;
1595         }
1596         head->read_eof = done;
1597         return 0;
1598 }
1599
1600 /**
1601  * tomoyo_write_domain_profile - Assign profile for specified domain.
1602  *
1603  * @head: Pointer to "struct tomoyo_io_buffer".
1604  *
1605  * Returns 0 on success, -EINVAL otherwise.
1606  *
1607  * This is equivalent to doing
1608  *
1609  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1610  *     /usr/lib/ccs/loadpolicy -d
1611  *
1612  * Caller holds tomoyo_read_lock().
1613  */
1614 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1615 {
1616         char *data = head->write_buf;
1617         char *cp = strchr(data, ' ');
1618         struct tomoyo_domain_info *domain;
1619         unsigned long profile;
1620
1621         if (!cp)
1622                 return -EINVAL;
1623         *cp = '\0';
1624         domain = tomoyo_find_domain(cp + 1);
1625         if (strict_strtoul(data, 10, &profile))
1626                 return -EINVAL;
1627         if (domain && profile < TOMOYO_MAX_PROFILES
1628             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1629                 domain->profile = (u8) profile;
1630         return 0;
1631 }
1632
1633 /**
1634  * tomoyo_read_domain_profile - Read only domainname and profile.
1635  *
1636  * @head: Pointer to "struct tomoyo_io_buffer".
1637  *
1638  * Returns list of profile number and domainname pairs.
1639  *
1640  * This is equivalent to doing
1641  *
1642  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1643  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1644  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1645  *     print $2 " " domainname; domainname = ""; } } ; '
1646  *
1647  * Caller holds tomoyo_read_lock().
1648  */
1649 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1650 {
1651         struct list_head *pos;
1652         bool done = true;
1653
1654         if (head->read_eof)
1655                 return 0;
1656         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1657                 struct tomoyo_domain_info *domain;
1658                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1659                 if (domain->is_deleted)
1660                         continue;
1661                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1662                                         domain->domainname->name);
1663                 if (!done)
1664                         break;
1665         }
1666         head->read_eof = done;
1667         return 0;
1668 }
1669
1670 /**
1671  * tomoyo_write_pid: Specify PID to obtain domainname.
1672  *
1673  * @head: Pointer to "struct tomoyo_io_buffer".
1674  *
1675  * Returns 0.
1676  */
1677 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1678 {
1679         unsigned long pid;
1680         /* No error check. */
1681         strict_strtoul(head->write_buf, 10, &pid);
1682         head->read_step = (int) pid;
1683         head->read_eof = false;
1684         return 0;
1685 }
1686
1687 /**
1688  * tomoyo_read_pid - Get domainname of the specified PID.
1689  *
1690  * @head: Pointer to "struct tomoyo_io_buffer".
1691  *
1692  * Returns the domainname which the specified PID is in on success,
1693  * empty string otherwise.
1694  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1695  * using read()/write() interface rather than sysctl() interface.
1696  */
1697 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1698 {
1699         if (head->read_avail == 0 && !head->read_eof) {
1700                 const int pid = head->read_step;
1701                 struct task_struct *p;
1702                 struct tomoyo_domain_info *domain = NULL;
1703                 rcu_read_lock();
1704                 read_lock(&tasklist_lock);
1705                 p = find_task_by_vpid(pid);
1706                 if (p)
1707                         domain = tomoyo_real_domain(p);
1708                 read_unlock(&tasklist_lock);
1709                 rcu_read_unlock();
1710                 if (domain)
1711                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1712                                          domain->domainname->name);
1713                 head->read_eof = true;
1714         }
1715         return 0;
1716 }
1717
1718 /**
1719  * tomoyo_write_exception_policy - Write exception policy.
1720  *
1721  * @head: Pointer to "struct tomoyo_io_buffer".
1722  *
1723  * Returns 0 on success, negative value otherwise.
1724  *
1725  * Caller holds tomoyo_read_lock().
1726  */
1727 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1728 {
1729         char *data = head->write_buf;
1730         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1731
1732         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1733                 return tomoyo_write_domain_keeper_policy(data, false,
1734                                                          is_delete);
1735         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1736                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1737         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1738                 return tomoyo_write_domain_initializer_policy(data, false,
1739                                                               is_delete);
1740         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1741                 return tomoyo_write_domain_initializer_policy(data, true,
1742                                                               is_delete);
1743         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1744                 return tomoyo_write_alias_policy(data, is_delete);
1745         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1746                 return tomoyo_write_globally_readable_policy(data, is_delete);
1747         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1748                 return tomoyo_write_pattern_policy(data, is_delete);
1749         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1750                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1751         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_PATH_GROUP))
1752                 return tomoyo_write_path_group_policy(data, is_delete);
1753         return -EINVAL;
1754 }
1755
1756 /**
1757  * tomoyo_read_exception_policy - Read exception policy.
1758  *
1759  * @head: Pointer to "struct tomoyo_io_buffer".
1760  *
1761  * Returns 0 on success, -EINVAL otherwise.
1762  *
1763  * Caller holds tomoyo_read_lock().
1764  */
1765 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1766 {
1767         if (!head->read_eof) {
1768                 switch (head->read_step) {
1769                 case 0:
1770                         head->read_var2 = NULL;
1771                         head->read_step = 1;
1772                 case 1:
1773                         if (!tomoyo_read_domain_keeper_policy(head))
1774                                 break;
1775                         head->read_var2 = NULL;
1776                         head->read_step = 2;
1777                 case 2:
1778                         if (!tomoyo_read_globally_readable_policy(head))
1779                                 break;
1780                         head->read_var2 = NULL;
1781                         head->read_step = 3;
1782                 case 3:
1783                         head->read_var2 = NULL;
1784                         head->read_step = 4;
1785                 case 4:
1786                         if (!tomoyo_read_domain_initializer_policy(head))
1787                                 break;
1788                         head->read_var2 = NULL;
1789                         head->read_step = 5;
1790                 case 5:
1791                         if (!tomoyo_read_alias_policy(head))
1792                                 break;
1793                         head->read_var2 = NULL;
1794                         head->read_step = 6;
1795                 case 6:
1796                         head->read_var2 = NULL;
1797                         head->read_step = 7;
1798                 case 7:
1799                         if (!tomoyo_read_file_pattern(head))
1800                                 break;
1801                         head->read_var2 = NULL;
1802                         head->read_step = 8;
1803                 case 8:
1804                         if (!tomoyo_read_no_rewrite_policy(head))
1805                                 break;
1806                         head->read_var2 = NULL;
1807                         head->read_step = 9;
1808                 case 9:
1809                         if (!tomoyo_read_path_group_policy(head))
1810                                 break;
1811                         head->read_var1 = NULL;
1812                         head->read_var2 = NULL;
1813                         head->read_step = 10;
1814                 case 10:
1815                         head->read_eof = true;
1816                         break;
1817                 default:
1818                         return -EINVAL;
1819                 }
1820         }
1821         return 0;
1822 }
1823
1824 /* path to policy loader */
1825 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1826
1827 /**
1828  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1829  *
1830  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1831  */
1832 static bool tomoyo_policy_loader_exists(void)
1833 {
1834         /*
1835          * Don't activate MAC if the policy loader doesn't exist.
1836          * If the initrd includes /sbin/init but real-root-dev has not
1837          * mounted on / yet, activating MAC will block the system since
1838          * policies are not loaded yet.
1839          * Thus, let do_execve() call this function everytime.
1840          */
1841         struct path path;
1842
1843         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1844                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1845                        "since %s doesn't exist.\n", tomoyo_loader);
1846                 return false;
1847         }
1848         path_put(&path);
1849         return true;
1850 }
1851
1852 /**
1853  * tomoyo_load_policy - Run external policy loader to load policy.
1854  *
1855  * @filename: The program about to start.
1856  *
1857  * This function checks whether @filename is /sbin/init , and if so
1858  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1859  * and then continues invocation of /sbin/init.
1860  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1861  * writes to /sys/kernel/security/tomoyo/ interfaces.
1862  *
1863  * Returns nothing.
1864  */
1865 void tomoyo_load_policy(const char *filename)
1866 {
1867         char *argv[2];
1868         char *envp[3];
1869
1870         if (tomoyo_policy_loaded)
1871                 return;
1872         /*
1873          * Check filename is /sbin/init or /sbin/tomoyo-start.
1874          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1875          * be passed.
1876          * You can create /sbin/tomoyo-start by
1877          * "ln -s /bin/true /sbin/tomoyo-start".
1878          */
1879         if (strcmp(filename, "/sbin/init") &&
1880             strcmp(filename, "/sbin/tomoyo-start"))
1881                 return;
1882         if (!tomoyo_policy_loader_exists())
1883                 return;
1884
1885         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1886                tomoyo_loader);
1887         argv[0] = (char *) tomoyo_loader;
1888         argv[1] = NULL;
1889         envp[0] = "HOME=/";
1890         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1891         envp[2] = NULL;
1892         call_usermodehelper(argv[0], argv, envp, 1);
1893
1894         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1895         printk(KERN_INFO "Mandatory Access Control activated.\n");
1896         tomoyo_policy_loaded = true;
1897         { /* Check all profiles currently assigned to domains are defined. */
1898                 struct tomoyo_domain_info *domain;
1899                 list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
1900                         const u8 profile = domain->profile;
1901                         if (tomoyo_profile_ptr[profile])
1902                                 continue;
1903                         panic("Profile %u (used by '%s') not defined.\n",
1904                               profile, domain->domainname->name);
1905                 }
1906         }
1907 }
1908
1909 /**
1910  * tomoyo_read_version: Get version.
1911  *
1912  * @head: Pointer to "struct tomoyo_io_buffer".
1913  *
1914  * Returns version information.
1915  */
1916 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1917 {
1918         if (!head->read_eof) {
1919                 tomoyo_io_printf(head, "2.2.0");
1920                 head->read_eof = true;
1921         }
1922         return 0;
1923 }
1924
1925 /**
1926  * tomoyo_read_self_domain - Get the current process's domainname.
1927  *
1928  * @head: Pointer to "struct tomoyo_io_buffer".
1929  *
1930  * Returns the current process's domainname.
1931  */
1932 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1933 {
1934         if (!head->read_eof) {
1935                 /*
1936                  * tomoyo_domain()->domainname != NULL
1937                  * because every process belongs to a domain and
1938                  * the domain's name cannot be NULL.
1939                  */
1940                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1941                 head->read_eof = true;
1942         }
1943         return 0;
1944 }
1945
1946 /**
1947  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1948  *
1949  * @type: Type of interface.
1950  * @file: Pointer to "struct file".
1951  *
1952  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1953  *
1954  * Caller acquires tomoyo_read_lock().
1955  */
1956 static int tomoyo_open_control(const u8 type, struct file *file)
1957 {
1958         struct tomoyo_io_buffer *head = kzalloc(sizeof(*head), GFP_NOFS);
1959
1960         if (!head)
1961                 return -ENOMEM;
1962         mutex_init(&head->io_sem);
1963         switch (type) {
1964         case TOMOYO_DOMAINPOLICY:
1965                 /* /sys/kernel/security/tomoyo/domain_policy */
1966                 head->write = tomoyo_write_domain_policy;
1967                 head->read = tomoyo_read_domain_policy;
1968                 break;
1969         case TOMOYO_EXCEPTIONPOLICY:
1970                 /* /sys/kernel/security/tomoyo/exception_policy */
1971                 head->write = tomoyo_write_exception_policy;
1972                 head->read = tomoyo_read_exception_policy;
1973                 break;
1974         case TOMOYO_SELFDOMAIN:
1975                 /* /sys/kernel/security/tomoyo/self_domain */
1976                 head->read = tomoyo_read_self_domain;
1977                 break;
1978         case TOMOYO_DOMAIN_STATUS:
1979                 /* /sys/kernel/security/tomoyo/.domain_status */
1980                 head->write = tomoyo_write_domain_profile;
1981                 head->read = tomoyo_read_domain_profile;
1982                 break;
1983         case TOMOYO_PROCESS_STATUS:
1984                 /* /sys/kernel/security/tomoyo/.process_status */
1985                 head->write = tomoyo_write_pid;
1986                 head->read = tomoyo_read_pid;
1987                 break;
1988         case TOMOYO_VERSION:
1989                 /* /sys/kernel/security/tomoyo/version */
1990                 head->read = tomoyo_read_version;
1991                 head->readbuf_size = 128;
1992                 break;
1993         case TOMOYO_MEMINFO:
1994                 /* /sys/kernel/security/tomoyo/meminfo */
1995                 head->write = tomoyo_write_memory_quota;
1996                 head->read = tomoyo_read_memory_counter;
1997                 head->readbuf_size = 512;
1998                 break;
1999         case TOMOYO_PROFILE:
2000                 /* /sys/kernel/security/tomoyo/profile */
2001                 head->write = tomoyo_write_profile;
2002                 head->read = tomoyo_read_profile;
2003                 break;
2004         case TOMOYO_MANAGER:
2005                 /* /sys/kernel/security/tomoyo/manager */
2006                 head->write = tomoyo_write_manager_policy;
2007                 head->read = tomoyo_read_manager_policy;
2008                 break;
2009         }
2010         if (!(file->f_mode & FMODE_READ)) {
2011                 /*
2012                  * No need to allocate read_buf since it is not opened
2013                  * for reading.
2014                  */
2015                 head->read = NULL;
2016         } else {
2017                 if (!head->readbuf_size)
2018                         head->readbuf_size = 4096 * 2;
2019                 head->read_buf = kzalloc(head->readbuf_size, GFP_NOFS);
2020                 if (!head->read_buf) {
2021                         kfree(head);
2022                         return -ENOMEM;
2023                 }
2024         }
2025         if (!(file->f_mode & FMODE_WRITE)) {
2026                 /*
2027                  * No need to allocate write_buf since it is not opened
2028                  * for writing.
2029                  */
2030                 head->write = NULL;
2031         } else if (head->write) {
2032                 head->writebuf_size = 4096 * 2;
2033                 head->write_buf = kzalloc(head->writebuf_size, GFP_NOFS);
2034                 if (!head->write_buf) {
2035                         kfree(head->read_buf);
2036                         kfree(head);
2037                         return -ENOMEM;
2038                 }
2039         }
2040         head->reader_idx = tomoyo_read_lock();
2041         file->private_data = head;
2042         /*
2043          * Call the handler now if the file is
2044          * /sys/kernel/security/tomoyo/self_domain
2045          * so that the user can use
2046          * cat < /sys/kernel/security/tomoyo/self_domain"
2047          * to know the current process's domainname.
2048          */
2049         if (type == TOMOYO_SELFDOMAIN)
2050                 tomoyo_read_control(file, NULL, 0);
2051         return 0;
2052 }
2053
2054 /**
2055  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
2056  *
2057  * @file:       Pointer to "struct file".
2058  * @buffer:     Poiner to buffer to write to.
2059  * @buffer_len: Size of @buffer.
2060  *
2061  * Returns bytes read on success, negative value otherwise.
2062  *
2063  * Caller holds tomoyo_read_lock().
2064  */
2065 static int tomoyo_read_control(struct file *file, char __user *buffer,
2066                                const int buffer_len)
2067 {
2068         int len = 0;
2069         struct tomoyo_io_buffer *head = file->private_data;
2070         char *cp;
2071
2072         if (!head->read)
2073                 return -ENOSYS;
2074         if (mutex_lock_interruptible(&head->io_sem))
2075                 return -EINTR;
2076         /* Call the policy handler. */
2077         len = head->read(head);
2078         if (len < 0)
2079                 goto out;
2080         /* Write to buffer. */
2081         len = head->read_avail;
2082         if (len > buffer_len)
2083                 len = buffer_len;
2084         if (!len)
2085                 goto out;
2086         /* head->read_buf changes by some functions. */
2087         cp = head->read_buf;
2088         if (copy_to_user(buffer, cp, len)) {
2089                 len = -EFAULT;
2090                 goto out;
2091         }
2092         head->read_avail -= len;
2093         memmove(cp, cp + len, head->read_avail);
2094  out:
2095         mutex_unlock(&head->io_sem);
2096         return len;
2097 }
2098
2099 /**
2100  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2101  *
2102  * @file:       Pointer to "struct file".
2103  * @buffer:     Pointer to buffer to read from.
2104  * @buffer_len: Size of @buffer.
2105  *
2106  * Returns @buffer_len on success, negative value otherwise.
2107  *
2108  * Caller holds tomoyo_read_lock().
2109  */
2110 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2111                                 const int buffer_len)
2112 {
2113         struct tomoyo_io_buffer *head = file->private_data;
2114         int error = buffer_len;
2115         int avail_len = buffer_len;
2116         char *cp0 = head->write_buf;
2117
2118         if (!head->write)
2119                 return -ENOSYS;
2120         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2121                 return -EFAULT;
2122         /* Don't allow updating policies by non manager programs. */
2123         if (head->write != tomoyo_write_pid &&
2124             head->write != tomoyo_write_domain_policy &&
2125             !tomoyo_is_policy_manager())
2126                 return -EPERM;
2127         if (mutex_lock_interruptible(&head->io_sem))
2128                 return -EINTR;
2129         /* Read a line and dispatch it to the policy handler. */
2130         while (avail_len > 0) {
2131                 char c;
2132                 if (head->write_avail >= head->writebuf_size - 1) {
2133                         error = -ENOMEM;
2134                         break;
2135                 } else if (get_user(c, buffer)) {
2136                         error = -EFAULT;
2137                         break;
2138                 }
2139                 buffer++;
2140                 avail_len--;
2141                 cp0[head->write_avail++] = c;
2142                 if (c != '\n')
2143                         continue;
2144                 cp0[head->write_avail - 1] = '\0';
2145                 head->write_avail = 0;
2146                 tomoyo_normalize_line(cp0);
2147                 head->write(head);
2148         }
2149         mutex_unlock(&head->io_sem);
2150         return error;
2151 }
2152
2153 /**
2154  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2155  *
2156  * @file: Pointer to "struct file".
2157  *
2158  * Releases memory and returns 0.
2159  *
2160  * Caller looses tomoyo_read_lock().
2161  */
2162 static int tomoyo_close_control(struct file *file)
2163 {
2164         struct tomoyo_io_buffer *head = file->private_data;
2165         const bool is_write = !!head->write_buf;
2166
2167         tomoyo_read_unlock(head->reader_idx);
2168         /* Release memory used for policy I/O. */
2169         kfree(head->read_buf);
2170         head->read_buf = NULL;
2171         kfree(head->write_buf);
2172         head->write_buf = NULL;
2173         kfree(head);
2174         head = NULL;
2175         file->private_data = NULL;
2176         if (is_write)
2177                 tomoyo_run_gc();
2178         return 0;
2179 }
2180
2181 /**
2182  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2183  *
2184  * @inode: Pointer to "struct inode".
2185  * @file:  Pointer to "struct file".
2186  *
2187  * Returns 0 on success, negative value otherwise.
2188  */
2189 static int tomoyo_open(struct inode *inode, struct file *file)
2190 {
2191         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2192                 - ((u8 *) NULL);
2193         return tomoyo_open_control(key, file);
2194 }
2195
2196 /**
2197  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2198  *
2199  * @inode: Pointer to "struct inode".
2200  * @file:  Pointer to "struct file".
2201  *
2202  * Returns 0 on success, negative value otherwise.
2203  */
2204 static int tomoyo_release(struct inode *inode, struct file *file)
2205 {
2206         return tomoyo_close_control(file);
2207 }
2208
2209 /**
2210  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2211  *
2212  * @file:  Pointer to "struct file".
2213  * @buf:   Pointer to buffer.
2214  * @count: Size of @buf.
2215  * @ppos:  Unused.
2216  *
2217  * Returns bytes read on success, negative value otherwise.
2218  */
2219 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2220                            loff_t *ppos)
2221 {
2222         return tomoyo_read_control(file, buf, count);
2223 }
2224
2225 /**
2226  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2227  *
2228  * @file:  Pointer to "struct file".
2229  * @buf:   Pointer to buffer.
2230  * @count: Size of @buf.
2231  * @ppos:  Unused.
2232  *
2233  * Returns @count on success, negative value otherwise.
2234  */
2235 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2236                             size_t count, loff_t *ppos)
2237 {
2238         return tomoyo_write_control(file, buf, count);
2239 }
2240
2241 /*
2242  * tomoyo_operations is a "struct file_operations" which is used for handling
2243  * /sys/kernel/security/tomoyo/ interface.
2244  *
2245  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2246  * See tomoyo_io_buffer for internals.
2247  */
2248 static const struct file_operations tomoyo_operations = {
2249         .open    = tomoyo_open,
2250         .release = tomoyo_release,
2251         .read    = tomoyo_read,
2252         .write   = tomoyo_write,
2253 };
2254
2255 /**
2256  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2257  *
2258  * @name:   The name of the interface file.
2259  * @mode:   The permission of the interface file.
2260  * @parent: The parent directory.
2261  * @key:    Type of interface.
2262  *
2263  * Returns nothing.
2264  */
2265 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2266                                        struct dentry *parent, const u8 key)
2267 {
2268         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2269                                &tomoyo_operations);
2270 }
2271
2272 /**
2273  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2274  *
2275  * Returns 0.
2276  */
2277 static int __init tomoyo_initerface_init(void)
2278 {
2279         struct dentry *tomoyo_dir;
2280
2281         /* Don't create securityfs entries unless registered. */
2282         if (current_cred()->security != &tomoyo_kernel_domain)
2283                 return 0;
2284
2285         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2286         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2287                             TOMOYO_DOMAINPOLICY);
2288         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2289                             TOMOYO_EXCEPTIONPOLICY);
2290         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2291                             TOMOYO_SELFDOMAIN);
2292         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2293                             TOMOYO_DOMAIN_STATUS);
2294         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2295                             TOMOYO_PROCESS_STATUS);
2296         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2297                             TOMOYO_MEMINFO);
2298         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2299                             TOMOYO_PROFILE);
2300         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2301                             TOMOYO_MANAGER);
2302         tomoyo_create_entry("version",          0400, tomoyo_dir,
2303                             TOMOYO_VERSION);
2304         return 0;
2305 }
2306
2307 fs_initcall(tomoyo_initerface_init);