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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-pre   2009/02/01
   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 /* Has loading policy done? */
  20 bool tomoyo_policy_loaded;
  21
  22 /* String table for functionality that takes 4 modes. */
  23 static const char *tomoyo_mode_4[4] = {
  24         "disabled", "learning", "permissive", "enforcing"
  25 };
  26 /* String table for functionality that takes 2 modes. */
  27 static const char *tomoyo_mode_2[4] = {
  28         "disabled", "enabled", "enabled", "enabled"
  29 };
  30
  31 /* Table for profile. */
  32 static struct {
  33         const char *keyword;
  34         unsigned int current_value;
  35         const unsigned int max_value;
  36 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
  37         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
  38         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
  39         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
  40 };
  41
  42 /* Profile table. Memory is allocated as needed. */
  43 static struct tomoyo_profile {
  44         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
  45         const struct tomoyo_path_info *comment;
  46 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
  47
  48 /* Permit policy management by non-root user? */
  49 static bool tomoyo_manage_by_non_root;
  50
  51 /* Utility functions. */
  52
  53 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
  54 static int tomoyo_open_control(const u8 type, struct file *file);
  55 /* Close /sys/kernel/security/tomoyo/ interface. */
  56 static int tomoyo_close_control(struct file *file);
  57 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
  58 static int tomoyo_read_control(struct file *file, char __user *buffer,
  59                                const int buffer_len);
  60 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
  61 static int tomoyo_write_control(struct file *file, const char __user *buffer,
  62                                 const int buffer_len);
  63
  64 /**
  65  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
  66  *
  67  * @str: Pointer to the string.
  68  *
  69  * Returns true if @str is a \ooo style octal value, false otherwise.
  70  *
  71  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
  72  * This function verifies that \ooo is in valid range.
  73  */
  74 static inline bool tomoyo_is_byte_range(const char *str)
  75 {
  76         return *str >= '0' && *str++ <= '3' &&
  77                 *str >= '0' && *str++ <= '7' &&
  78                 *str >= '0' && *str <= '7';
  79 }
  80
  81 /**
  82  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
  83  *
  84  * @c: The character to check.
  85  *
  86  * Returns true if @c is an alphabet character, false otherwise.
  87  */
  88 static inline bool tomoyo_is_alphabet_char(const char c)
  89 {
  90         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
  91 }
  92
  93 /**
  94  * tomoyo_make_byte - Make byte value from three octal characters.
  95  *
  96  * @c1: The first character.
  97  * @c2: The second character.
  98  * @c3: The third character.
  99  *
 100  * Returns byte value.
 101  */
 102 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 103 {
 104         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 105 }
 106
 107 /**
 108  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 109  *
 110  * @src:  Pointer to pointer to the string.
 111  * @find: Pointer to the keyword.
 112  *
 113  * Returns true if @src starts with @find, false otherwise.
 114  *
 115  * The @src is updated to point the first character after the @find
 116  * if @src starts with @find.
 117  */
 118 static bool tomoyo_str_starts(char **src, const char *find)
 119 {
 120         const int len = strlen(find);
 121         char *tmp = *src;
 122
 123         if (strncmp(tmp, find, len))
 124                 return false;
 125         tmp += len;
 126         *src = tmp;
 127         return true;
 128 }
 129
 130 /**
 131  * tomoyo_normalize_line - Format string.
 132  *
 133  * @buffer: The line to normalize.
 134  *
 135  * Leading and trailing whitespaces are removed.
 136  * Multiple whitespaces are packed into single space.
 137  *
 138  * Returns nothing.
 139  */
 140 static void tomoyo_normalize_line(unsigned char *buffer)
 141 {
 142         unsigned char *sp = buffer;
 143         unsigned char *dp = buffer;
 144         bool first = true;
 145
 146         while (tomoyo_is_invalid(*sp))
 147                 sp++;
 148         while (*sp) {
 149                 if (!first)
 150                         *dp++ = ' ';
 151                 first = false;
 152                 while (tomoyo_is_valid(*sp))
 153                         *dp++ = *sp++;
 154                 while (tomoyo_is_invalid(*sp))
 155                         sp++;
 156         }
 157         *dp = '\0';
 158 }
 159
 160 /**
 161  * tomoyo_is_correct_path - Validate a pathname.
 162  * @filename:     The pathname to check.
 163  * @start_type:   Should the pathname start with '/'?
 164  *                1 = must / -1 = must not / 0 = don't care
 165  * @pattern_type: Can the pathname contain a wildcard?
 166  *                1 = must / -1 = must not / 0 = don't care
 167  * @end_type:     Should the pathname end with '/'?
 168  *                1 = must / -1 = must not / 0 = don't care
 169  * @function:     The name of function calling me.
 170  *
 171  * Check whether the given filename follows the naming rules.
 172  * Returns true if @filename follows the naming rules, false otherwise.
 173  */
 174 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 175                             const s8 pattern_type, const s8 end_type,
 176                             const char *function)
 177 {
 178         bool contains_pattern = false;
 179         unsigned char c;
 180         unsigned char d;
 181         unsigned char e;
 182         const char *original_filename = filename;
 183
 184         if (!filename)
 185                 goto out;
 186         c = *filename;
 187         if (start_type == 1) { /* Must start with '/' */
 188                 if (c != '/')
 189                         goto out;
 190         } else if (start_type == -1) { /* Must not start with '/' */
 191                 if (c == '/')
 192                         goto out;
 193         }
 194         if (c)
 195                 c = *(filename + strlen(filename) - 1);
 196         if (end_type == 1) { /* Must end with '/' */
 197                 if (c != '/')
 198                         goto out;
 199         } else if (end_type == -1) { /* Must not end with '/' */
 200                 if (c == '/')
 201                         goto out;
 202         }
 203         while ((c = *filename++) != '\0') {
 204                 if (c == '\\') {
 205                         switch ((c = *filename++)) {
 206                         case '\\':  /* "\\" */
 207                                 continue;
 208                         case '$':   /* "\$" */
 209                         case '+':   /* "\+" */
 210                         case '?':   /* "\?" */
 211                         case '*':   /* "\*" */
 212                         case '@':   /* "\@" */
 213                         case 'x':   /* "\x" */
 214                         case 'X':   /* "\X" */
 215                         case 'a':   /* "\a" */
 216                         case 'A':   /* "\A" */
 217                         case '-':   /* "\-" */
 218                                 if (pattern_type == -1)
 219                                         break; /* Must not contain pattern */
 220                                 contains_pattern = true;
 221                                 continue;
 222                         case '0':   /* "\ooo" */
 223                         case '1':
 224                         case '2':
 225                         case '3':
 226                                 d = *filename++;
 227                                 if (d < '0' || d > '7')
 228                                         break;
 229                                 e = *filename++;
 230                                 if (e < '0' || e > '7')
 231                                         break;
 232                                 c = tomoyo_make_byte(c, d, e);
 233                                 if (tomoyo_is_invalid(c))
 234                                         continue; /* pattern is not \000 */
 235                         }
 236                         goto out;
 237                 } else if (tomoyo_is_invalid(c)) {
 238                         goto out;
 239                 }
 240         }
 241         if (pattern_type == 1) { /* Must contain pattern */
 242                 if (!contains_pattern)
 243                         goto out;
 244         }
 245         return true;
 246  out:
 247         printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function,
 248                original_filename);
 249         return false;
 250 }
 251
 252 /**
 253  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 254  * @domainname:   The domainname to check.
 255  * @function:     The name of function calling me.
 256  *
 257  * Returns true if @domainname follows the naming rules, false otherwise.
 258  */
 259 bool tomoyo_is_correct_domain(const unsigned char *domainname,
 260                               const char *function)
 261 {
 262         unsigned char c;
 263         unsigned char d;
 264         unsigned char e;
 265         const char *org_domainname = domainname;
 266
 267         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 268                                    TOMOYO_ROOT_NAME_LEN))
 269                 goto out;
 270         domainname += TOMOYO_ROOT_NAME_LEN;
 271         if (!*domainname)
 272                 return true;
 273         do {
 274                 if (*domainname++ != ' ')
 275                         goto out;
 276                 if (*domainname++ != '/')
 277                         goto out;
 278                 while ((c = *domainname) != '\0' && c != ' ') {
 279                         domainname++;
 280                         if (c == '\\') {
 281                                 c = *domainname++;
 282                                 switch ((c)) {
 283                                 case '\\':  /* "\\" */
 284                                         continue;
 285                                 case '0':   /* "\ooo" */
 286                                 case '1':
 287                                 case '2':
 288                                 case '3':
 289                                         d = *domainname++;
 290                                         if (d < '0' || d > '7')
 291                                                 break;
 292                                         e = *domainname++;
 293                                         if (e < '0' || e > '7')
 294                                                 break;
 295                                         c = tomoyo_make_byte(c, d, e);
 296                                         if (tomoyo_is_invalid(c))
 297                                                 /* pattern is not \000 */
 298                                                 continue;
 299                                 }
 300                                 goto out;
 301                         } else if (tomoyo_is_invalid(c)) {
 302                                 goto out;
 303                         }
 304                 }
 305         } while (*domainname);
 306         return true;
 307  out:
 308         printk(KERN_DEBUG "%s: Invalid domainname '%s'\n", function,
 309                org_domainname);
 310         return false;
 311 }
 312
 313 /**
 314  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 315  *
 316  * @buffer: The token to check.
 317  *
 318  * Returns true if @buffer possibly be a domainname, false otherwise.
 319  */
 320 bool tomoyo_is_domain_def(const unsigned char *buffer)
 321 {
 322         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 323 }
 324
 325 /**
 326  * tomoyo_find_domain - Find a domain by the given name.
 327  *
 328  * @domainname: The domainname to find.
 329  *
 330  * Caller must call down_read(&tomoyo_domain_list_lock); or
 331  * down_write(&tomoyo_domain_list_lock); .
 332  *
 333  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 334  */
 335 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 336 {
 337         struct tomoyo_domain_info *domain;
 338         struct tomoyo_path_info name;
 339
 340         name.name = domainname;
 341         tomoyo_fill_path_info(&name);
 342         list_for_each_entry(domain, &tomoyo_domain_list, list) {
 343                 if (!domain->is_deleted &&
 344                     !tomoyo_pathcmp(&name, domain->domainname))
 345                         return domain;
 346         }
 347         return NULL;
 348 }
 349
 350 /**
 351  * tomoyo_path_depth - Evaluate the number of '/' in a string.
 352  *
 353  * @pathname: The string to evaluate.
 354  *
 355  * Returns path depth of the string.
 356  *
 357  * I score 2 for each of the '/' in the @pathname
 358  * and score 1 if the @pathname ends with '/'.
 359  */
 360 static int tomoyo_path_depth(const char *pathname)
 361 {
 362         int i = 0;
 363
 364         if (pathname) {
 365                 const char *ep = pathname + strlen(pathname);
 366                 if (pathname < ep--) {
 367                         if (*ep != '/')
 368                                 i++;
 369                         while (pathname <= ep)
 370                                 if (*ep-- == '/')
 371                                         i += 2;
 372                 }
 373         }
 374         return i;
 375 }
 376
 377 /**
 378  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 379  *
 380  * @filename: The string to evaluate.
 381  *
 382  * Returns the initial length without a pattern in @filename.
 383  */
 384 static int tomoyo_const_part_length(const char *filename)
 385 {
 386         char c;
 387         int len = 0;
 388
 389         if (!filename)
 390                 return 0;
 391         while ((c = *filename++) != '\0') {
 392                 if (c != '\\') {
 393                         len++;
 394                         continue;
 395                 }
 396                 c = *filename++;
 397                 switch (c) {
 398                 case '\\':  /* "\\" */
 399                         len += 2;
 400                         continue;
 401                 case '0':   /* "\ooo" */
 402                 case '1':
 403                 case '2':
 404                 case '3':
 405                         c = *filename++;
 406                         if (c < '0' || c > '7')
 407                                 break;
 408                         c = *filename++;
 409                         if (c < '0' || c > '7')
 410                                 break;
 411                         len += 4;
 412                         continue;
 413                 }
 414                 break;
 415         }
 416         return len;
 417 }
 418
 419 /**
 420  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 421  *
 422  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 423  *
 424  * The caller sets "struct tomoyo_path_info"->name.
 425  */
 426 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 427 {
 428         const char *name = ptr->name;
 429         const int len = strlen(name);
 430
 431         ptr->total_len = len;
 432         ptr->const_len = tomoyo_const_part_length(name);
 433         ptr->is_dir = len && (name[len - 1] == '/');
 434         ptr->is_patterned = (ptr->const_len < len);
 435         ptr->hash = full_name_hash(name, len);
 436         ptr->depth = tomoyo_path_depth(name);
 437 }
 438
 439 /**
 440  * tomoyo_file_matches_to_pattern2 - Pattern matching without '/' character
 441  * and "\-" pattern.
 442  *
 443  * @filename:     The start of string to check.
 444  * @filename_end: The end of string to check.
 445  * @pattern:      The start of pattern to compare.
 446  * @pattern_end:  The end of pattern to compare.
 447  *
 448  * Returns true if @filename matches @pattern, false otherwise.
 449  */
 450 static bool tomoyo_file_matches_to_pattern2(const char *filename,
 451                                             const char *filename_end,
 452                                             const char *pattern,
 453                                             const char *pattern_end)
 454 {
 455         while (filename < filename_end && pattern < pattern_end) {
 456                 char c;
 457                 if (*pattern != '\\') {
 458                         if (*filename++ != *pattern++)
 459                                 return false;
 460                         continue;
 461                 }
 462                 c = *filename;
 463                 pattern++;
 464                 switch (*pattern) {
 465                         int i;
 466                         int j;
 467                 case '?':
 468                         if (c == '/') {
 469                                 return false;
 470                         } else if (c == '\\') {
 471                                 if (filename[1] == '\\')
 472                                         filename++;
 473                                 else if (tomoyo_is_byte_range(filename + 1))
 474                                         filename += 3;
 475                                 else
 476                                         return false;
 477                         }
 478                         break;
 479                 case '\\':
 480                         if (c != '\\')
 481                                 return false;
 482                         if (*++filename != '\\')
 483                                 return false;
 484                         break;
 485                 case '+':
 486                         if (!isdigit(c))
 487                                 return false;
 488                         break;
 489                 case 'x':
 490                         if (!isxdigit(c))
 491                                 return false;
 492                         break;
 493                 case 'a':
 494                         if (!tomoyo_is_alphabet_char(c))
 495                                 return false;
 496                         break;
 497                 case '0':
 498                 case '1':
 499                 case '2':
 500                 case '3':
 501                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 502                             && strncmp(filename + 1, pattern, 3) == 0) {
 503                                 filename += 3;
 504                                 pattern += 2;
 505                                 break;
 506                         }
 507                         return false; /* Not matched. */
 508                 case '*':
 509                 case '@':
 510                         for (i = 0; i <= filename_end - filename; i++) {
 511                                 if (tomoyo_file_matches_to_pattern2(
 512                                                     filename + i, filename_end,
 513                                                     pattern + 1, pattern_end))
 514                                         return true;
 515                                 c = filename[i];
 516                                 if (c == '.' && *pattern == '@')
 517                                         break;
 518                                 if (c != '\\')
 519                                         continue;
 520                                 if (filename[i + 1] == '\\')
 521                                         i++;
 522                                 else if (tomoyo_is_byte_range(filename + i + 1))
 523                                         i += 3;
 524                                 else
 525                                         break; /* Bad pattern. */
 526                         }
 527                         return false; /* Not matched. */
 528                 default:
 529                         j = 0;
 530                         c = *pattern;
 531                         if (c == '$') {
 532                                 while (isdigit(filename[j]))
 533                                         j++;
 534                         } else if (c == 'X') {
 535                                 while (isxdigit(filename[j]))
 536                                         j++;
 537                         } else if (c == 'A') {
 538                                 while (tomoyo_is_alphabet_char(filename[j]))
 539                                         j++;
 540                         }
 541                         for (i = 1; i <= j; i++) {
 542                                 if (tomoyo_file_matches_to_pattern2(
 543                                                     filename + i, filename_end,
 544                                                     pattern + 1, pattern_end))
 545                                         return true;
 546                         }
 547                         return false; /* Not matched or bad pattern. */
 548                 }
 549                 filename++;
 550                 pattern++;
 551         }
 552         while (*pattern == '\\' &&
 553                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 554                 pattern += 2;
 555         return filename == filename_end && pattern == pattern_end;
 556 }
 557
 558 /**
 559  * tomoyo_file_matches_to_pattern - Pattern matching without without '/' character.
 560  *
 561  * @filename:     The start of string to check.
 562  * @filename_end: The end of string to check.
 563  * @pattern:      The start of pattern to compare.
 564  * @pattern_end:  The end of pattern to compare.
 565  *
 566  * Returns true if @filename matches @pattern, false otherwise.
 567  */
 568 static bool tomoyo_file_matches_to_pattern(const char *filename,
 569                                            const char *filename_end,
 570                                            const char *pattern,
 571                                            const char *pattern_end)
 572 {
 573         const char *pattern_start = pattern;
 574         bool first = true;
 575         bool result;
 576
 577         while (pattern < pattern_end - 1) {
 578                 /* Split at "\-" pattern. */
 579                 if (*pattern++ != '\\' || *pattern++ != '-')
 580                         continue;
 581                 result = tomoyo_file_matches_to_pattern2(filename,
 582                                                          filename_end,
 583                                                          pattern_start,
 584                                                          pattern - 2);
 585                 if (first)
 586                         result = !result;
 587                 if (result)
 588                         return false;
 589                 first = false;
 590                 pattern_start = pattern;
 591         }
 592         result = tomoyo_file_matches_to_pattern2(filename, filename_end,
 593                                                  pattern_start, pattern_end);
 594         return first ? result : !result;
 595 }
 596
 597 /**
 598  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 599  * @filename: The filename to check.
 600  * @pattern:  The pattern to compare.
 601  *
 602  * Returns true if matches, false otherwise.
 603  *
 604  * The following patterns are available.
 605  *   \\     \ itself.
 606  *   \ooo   Octal representation of a byte.
 607  *   \*     More than or equals to 0 character other than '/'.
 608  *   \@     More than or equals to 0 character other than '/' or '.'.
 609  *   \?     1 byte character other than '/'.
 610  *   \$     More than or equals to 1 decimal digit.
 611  *   \+     1 decimal digit.
 612  *   \X     More than or equals to 1 hexadecimal digit.
 613  *   \x     1 hexadecimal digit.
 614  *   \A     More than or equals to 1 alphabet character.
 615  *   \a     1 alphabet character.
 616  *   \-     Subtraction operator.
 617  */
 618 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 619                                  const struct tomoyo_path_info *pattern)
 620 {
 621         /*
 622           if (!filename || !pattern)
 623           return false;
 624         */
 625         const char *f = filename->name;
 626         const char *p = pattern->name;
 627         const int len = pattern->const_len;
 628
 629         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 630         if (!pattern->is_patterned)
 631                 return !tomoyo_pathcmp(filename, pattern);
 632         /* Dont compare if the number of '/' differs. */
 633         if (filename->depth != pattern->depth)
 634                 return false;
 635         /* Compare the initial length without patterns. */
 636         if (strncmp(f, p, len))
 637                 return false;
 638         f += len;
 639         p += len;
 640         /* Main loop. Compare each directory component. */
 641         while (*f && *p) {
 642                 const char *f_delimiter = strchr(f, '/');
 643                 const char *p_delimiter = strchr(p, '/');
 644                 if (!f_delimiter)
 645                         f_delimiter = f + strlen(f);
 646                 if (!p_delimiter)
 647                         p_delimiter = p + strlen(p);
 648                 if (!tomoyo_file_matches_to_pattern(f, f_delimiter,
 649                                                     p, p_delimiter))
 650                         return false;
 651                 f = f_delimiter;
 652                 if (*f)
 653                         f++;
 654                 p = p_delimiter;
 655                 if (*p)
 656                         p++;
 657         }
 658         /* Ignore trailing "\*" and "\@" in @pattern. */
 659         while (*p == '\\' &&
 660                (*(p + 1) == '*' || *(p + 1) == '@'))
 661                 p += 2;
 662         return !*f && !*p;
 663 }
 664
 665 /**
 666  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 667  *
 668  * @head: Pointer to "struct tomoyo_io_buffer".
 669  * @fmt:  The printf()'s format string, followed by parameters.
 670  *
 671  * Returns true if output was written, false otherwise.
 672  *
 673  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 674  */
 675 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 676 {
 677         va_list args;
 678         int len;
 679         int pos = head->read_avail;
 680         int size = head->readbuf_size - pos;
 681
 682         if (size <= 0)
 683                 return false;
 684         va_start(args, fmt);
 685         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 686         va_end(args);
 687         if (pos + len >= head->readbuf_size)
 688                 return false;
 689         head->read_avail += len;
 690         return true;
 691 }
 692
 693 /**
 694  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 695  *
 696  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 697  *
 698  * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
 699  * if this function didn't return NULL.
 700  */
 701 static const char *tomoyo_get_exe(void)
 702 {
 703         struct mm_struct *mm = current->mm;
 704         struct vm_area_struct *vma;
 705         const char *cp = NULL;
 706
 707         if (!mm)
 708                 return NULL;
 709         down_read(&mm->mmap_sem);
 710         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 711                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 712                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 713                         break;
 714                 }
 715         }
 716         up_read(&mm->mmap_sem);
 717         return cp;
 718 }
 719
 720 /**
 721  * tomoyo_get_msg - Get warning message.
 722  *
 723  * @is_enforce: Is it enforcing mode?
 724  *
 725  * Returns "ERROR" or "WARNING".
 726  */
 727 const char *tomoyo_get_msg(const bool is_enforce)
 728 {
 729         if (is_enforce)
 730                 return "ERROR";
 731         else
 732                 return "WARNING";
 733 }
 734
 735 /**
 736  * tomoyo_check_flags - Check mode for specified functionality.
 737  *
 738  * @domain: Pointer to "struct tomoyo_domain_info".
 739  * @index:  The functionality to check mode.
 740  *
 741  * TOMOYO checks only process context.
 742  * This code disables TOMOYO's enforcement in case the function is called from
 743  * interrupt context.
 744  */
 745 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 746                                 const u8 index)
 747 {
 748         const u8 profile = domain->profile;
 749
 750         if (WARN_ON(in_interrupt()))
 751                 return 0;
 752         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 753 #if TOMOYO_MAX_PROFILES != 256
 754                 && profile < TOMOYO_MAX_PROFILES
 755 #endif
 756                 && tomoyo_profile_ptr[profile] ?
 757                 tomoyo_profile_ptr[profile]->value[index] : 0;
 758 }
 759
 760 /**
 761  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 762  *
 763  * @domain: Pointer to "struct tomoyo_domain_info".
 764  *
 765  * Returns true if domain policy violation warning should be printed to
 766  * console.
 767  */
 768 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 769 {
 770         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 771 }
 772
 773 /**
 774  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 775  *
 776  * @domain: Pointer to "struct tomoyo_domain_info".
 777  *
 778  * Returns true if the domain is not exceeded quota, false otherwise.
 779  */
 780 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 781 {
 782         unsigned int count = 0;
 783         struct tomoyo_acl_info *ptr;
 784
 785         if (!domain)
 786                 return true;
 787         down_read(&tomoyo_domain_acl_info_list_lock);
 788         list_for_each_entry(ptr, &domain->acl_info_list, list) {
 789                 if (ptr->type & TOMOYO_ACL_DELETED)
 790                         continue;
 791                 switch (tomoyo_acl_type2(ptr)) {
 792                         struct tomoyo_single_path_acl_record *acl1;
 793                         struct tomoyo_double_path_acl_record *acl2;
 794                         u16 perm;
 795                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
 796                         acl1 = container_of(ptr,
 797                                     struct tomoyo_single_path_acl_record,
 798                                             head);
 799                         perm = acl1->perm;
 800                         if (perm & (1 << TOMOYO_TYPE_EXECUTE_ACL))
 801                                 count++;
 802                         if (perm &
 803                             ((1 << TOMOYO_TYPE_READ_ACL) |
 804                              (1 << TOMOYO_TYPE_WRITE_ACL)))
 805                                 count++;
 806                         if (perm & (1 << TOMOYO_TYPE_CREATE_ACL))
 807                                 count++;
 808                         if (perm & (1 << TOMOYO_TYPE_UNLINK_ACL))
 809                                 count++;
 810                         if (perm & (1 << TOMOYO_TYPE_MKDIR_ACL))
 811                                 count++;
 812                         if (perm & (1 << TOMOYO_TYPE_RMDIR_ACL))
 813                                 count++;
 814                         if (perm & (1 << TOMOYO_TYPE_MKFIFO_ACL))
 815                                 count++;
 816                         if (perm & (1 << TOMOYO_TYPE_MKSOCK_ACL))
 817                                 count++;
 818                         if (perm & (1 << TOMOYO_TYPE_MKBLOCK_ACL))
 819                                 count++;
 820                         if (perm & (1 << TOMOYO_TYPE_MKCHAR_ACL))
 821                                 count++;
 822                         if (perm & (1 << TOMOYO_TYPE_TRUNCATE_ACL))
 823                                 count++;
 824                         if (perm & (1 << TOMOYO_TYPE_SYMLINK_ACL))
 825                                 count++;
 826                         if (perm & (1 << TOMOYO_TYPE_REWRITE_ACL))
 827                                 count++;
 828                         break;
 829                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
 830                         acl2 = container_of(ptr,
 831                                     struct tomoyo_double_path_acl_record,
 832                                             head);
 833                         perm = acl2->perm;
 834                         if (perm & (1 << TOMOYO_TYPE_LINK_ACL))
 835                                 count++;
 836                         if (perm & (1 << TOMOYO_TYPE_RENAME_ACL))
 837                                 count++;
 838                         break;
 839                 }
 840         }
 841         up_read(&tomoyo_domain_acl_info_list_lock);
 842         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 843                 return true;
 844         if (!domain->quota_warned) {
 845                 domain->quota_warned = true;
 846                 printk(KERN_WARNING "TOMOYO-WARNING: "
 847                        "Domain '%s' has so many ACLs to hold. "
 848                        "Stopped learning mode.\n", domain->domainname->name);
 849         }
 850         return false;
 851 }
 852
 853 /**
 854  * tomoyo_find_or_assign_new_profile - Create a new profile.
 855  *
 856  * @profile: Profile number to create.
 857  *
 858  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 859  */
 860 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 861                                                                 int profile)
 862 {
 863         static DEFINE_MUTEX(lock);
 864         struct tomoyo_profile *ptr = NULL;
 865         int i;
 866
 867         if (profile >= TOMOYO_MAX_PROFILES)
 868                 return NULL;
 869         /***** EXCLUSIVE SECTION START *****/
 870         mutex_lock(&lock);
 871         ptr = tomoyo_profile_ptr[profile];
 872         if (ptr)
 873                 goto ok;
 874         ptr = tomoyo_alloc_element(sizeof(*ptr));
 875         if (!ptr)
 876                 goto ok;
 877         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 878                 ptr->value[i] = tomoyo_control_array[i].current_value;
 879         mb(); /* Avoid out-of-order execution. */
 880         tomoyo_profile_ptr[profile] = ptr;
 881  ok:
 882         mutex_unlock(&lock);
 883         /***** EXCLUSIVE SECTION END *****/
 884         return ptr;
 885 }
 886
 887 /**
 888  * tomoyo_write_profile - Write to profile table.
 889  *
 890  * @head: Pointer to "struct tomoyo_io_buffer".
 891  *
 892  * Returns 0 on success, negative value otherwise.
 893  */
 894 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 895 {
 896         char *data = head->write_buf;
 897         unsigned int i;
 898         unsigned int value;
 899         char *cp;
 900         struct tomoyo_profile *profile;
 901         unsigned long num;
 902
 903         cp = strchr(data, '-');
 904         if (cp)
 905                 *cp = '\0';
 906         if (strict_strtoul(data, 10, &num))
 907                 return -EINVAL;
 908         if (cp)
 909                 data = cp + 1;
 910         profile = tomoyo_find_or_assign_new_profile(num);
 911         if (!profile)
 912                 return -EINVAL;
 913         cp = strchr(data, '=');
 914         if (!cp)
 915                 return -EINVAL;
 916         *cp = '\0';
 917         if (!strcmp(data, "COMMENT")) {
 918                 profile->comment = tomoyo_save_name(cp + 1);
 919                 return 0;
 920         }
 921         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 922                 if (strcmp(data, tomoyo_control_array[i].keyword))
 923                         continue;
 924                 if (sscanf(cp + 1, "%u", &value) != 1) {
 925                         int j;
 926                         const char **modes;
 927                         switch (i) {
 928                         case TOMOYO_VERBOSE:
 929                                 modes = tomoyo_mode_2;
 930                                 break;
 931                         default:
 932                                 modes = tomoyo_mode_4;
 933                                 break;
 934                         }
 935                         for (j = 0; j < 4; j++) {
 936                                 if (strcmp(cp + 1, modes[j]))
 937                                         continue;
 938                                 value = j;
 939                                 break;
 940                         }
 941                         if (j == 4)
 942                                 return -EINVAL;
 943                 } else if (value > tomoyo_control_array[i].max_value) {
 944                         value = tomoyo_control_array[i].max_value;
 945                 }
 946                 profile->value[i] = value;
 947                 return 0;
 948         }
 949         return -EINVAL;
 950 }
 951
 952 /**
 953  * tomoyo_read_profile - Read from profile table.
 954  *
 955  * @head: Pointer to "struct tomoyo_io_buffer".
 956  *
 957  * Returns 0.
 958  */
 959 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 960 {
 961         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 962         int step;
 963
 964         if (head->read_eof)
 965                 return 0;
 966         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 967              step++) {
 968                 const u8 index = step / total;
 969                 u8 type = step % total;
 970                 const struct tomoyo_profile *profile
 971                         = tomoyo_profile_ptr[index];
 972                 head->read_step = step;
 973                 if (!profile)
 974                         continue;
 975                 if (!type) { /* Print profile' comment tag. */
 976                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
 977                                               index, profile->comment ?
 978                                               profile->comment->name : ""))
 979                                 break;
 980                         continue;
 981                 }
 982                 type--;
 983                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
 984                         const unsigned int value = profile->value[type];
 985                         const char **modes = NULL;
 986                         const char *keyword
 987                                 = tomoyo_control_array[type].keyword;
 988                         switch (tomoyo_control_array[type].max_value) {
 989                         case 3:
 990                                 modes = tomoyo_mode_4;
 991                                 break;
 992                         case 1:
 993                                 modes = tomoyo_mode_2;
 994                                 break;
 995                         }
 996                         if (modes) {
 997                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
 998                                                       keyword, modes[value]))
 999                                         break;
1000                         } else {
1001                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1002                                                       keyword, value))
1003                                         break;
1004                         }
1005                 }
1006         }
1007         if (step == TOMOYO_MAX_PROFILES * total)
1008                 head->read_eof = true;
1009         return 0;
1010 }
1011
1012 /* Structure for policy manager. */
1013 struct tomoyo_policy_manager_entry {
1014         struct list_head list;
1015         /* A path to program or a domainname. */
1016         const struct tomoyo_path_info *manager;
1017         bool is_domain;  /* True if manager is a domainname. */
1018         bool is_deleted; /* True if this entry is deleted. */
1019 };
1020
1021 /* The list for "struct tomoyo_policy_manager_entry". */
1022 static LIST_HEAD(tomoyo_policy_manager_list);
1023 static DECLARE_RWSEM(tomoyo_policy_manager_list_lock);
1024
1025 /**
1026  * tomoyo_update_manager_entry - Add a manager entry.
1027  *
1028  * @manager:   The path to manager or the domainnamme.
1029  * @is_delete: True if it is a delete request.
1030  *
1031  * Returns 0 on success, negative value otherwise.
1032  */
1033 static int tomoyo_update_manager_entry(const char *manager,
1034                                        const bool is_delete)
1035 {
1036         struct tomoyo_policy_manager_entry *new_entry;
1037         struct tomoyo_policy_manager_entry *ptr;
1038         const struct tomoyo_path_info *saved_manager;
1039         int error = -ENOMEM;
1040         bool is_domain = false;
1041
1042         if (tomoyo_is_domain_def(manager)) {
1043                 if (!tomoyo_is_correct_domain(manager, __func__))
1044                         return -EINVAL;
1045                 is_domain = true;
1046         } else {
1047                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1048                         return -EINVAL;
1049         }
1050         saved_manager = tomoyo_save_name(manager);
1051         if (!saved_manager)
1052                 return -ENOMEM;
1053         /***** EXCLUSIVE SECTION START *****/
1054         down_write(&tomoyo_policy_manager_list_lock);
1055         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1056                 if (ptr->manager != saved_manager)
1057                         continue;
1058                 ptr->is_deleted = is_delete;
1059                 error = 0;
1060                 goto out;
1061         }
1062         if (is_delete) {
1063                 error = -ENOENT;
1064                 goto out;
1065         }
1066         new_entry = tomoyo_alloc_element(sizeof(*new_entry));
1067         if (!new_entry)
1068                 goto out;
1069         new_entry->manager = saved_manager;
1070         new_entry->is_domain = is_domain;
1071         list_add_tail(&new_entry->list, &tomoyo_policy_manager_list);
1072         error = 0;
1073  out:
1074         up_write(&tomoyo_policy_manager_list_lock);
1075         /***** EXCLUSIVE SECTION END *****/
1076         return error;
1077 }
1078
1079 /**
1080  * tomoyo_write_manager_policy - Write manager policy.
1081  *
1082  * @head: Pointer to "struct tomoyo_io_buffer".
1083  *
1084  * Returns 0 on success, negative value otherwise.
1085  */
1086 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1087 {
1088         char *data = head->write_buf;
1089         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1090
1091         if (!strcmp(data, "manage_by_non_root")) {
1092                 tomoyo_manage_by_non_root = !is_delete;
1093                 return 0;
1094         }
1095         return tomoyo_update_manager_entry(data, is_delete);
1096 }
1097
1098 /**
1099  * tomoyo_read_manager_policy - Read manager policy.
1100  *
1101  * @head: Pointer to "struct tomoyo_io_buffer".
1102  *
1103  * Returns 0.
1104  */
1105 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1106 {
1107         struct list_head *pos;
1108         bool done = true;
1109
1110         if (head->read_eof)
1111                 return 0;
1112         down_read(&tomoyo_policy_manager_list_lock);
1113         list_for_each_cookie(pos, head->read_var2,
1114                              &tomoyo_policy_manager_list) {
1115                 struct tomoyo_policy_manager_entry *ptr;
1116                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1117                                  list);
1118                 if (ptr->is_deleted)
1119                         continue;
1120                 if (!tomoyo_io_printf(head, "%s\n", ptr->manager->name)) {
1121                         done = false;
1122                         break;
1123                 }
1124         }
1125         up_read(&tomoyo_policy_manager_list_lock);
1126         head->read_eof = done;
1127         return 0;
1128 }
1129
1130 /**
1131  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1132  *
1133  * Returns true if the current process is permitted to modify policy
1134  * via /sys/kernel/security/tomoyo/ interface.
1135  */
1136 static bool tomoyo_is_policy_manager(void)
1137 {
1138         struct tomoyo_policy_manager_entry *ptr;
1139         const char *exe;
1140         const struct task_struct *task = current;
1141         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1142         bool found = false;
1143
1144         if (!tomoyo_policy_loaded)
1145                 return true;
1146         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1147                 return false;
1148         down_read(&tomoyo_policy_manager_list_lock);
1149         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1150                 if (!ptr->is_deleted && ptr->is_domain
1151                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1152                         found = true;
1153                         break;
1154                 }
1155         }
1156         up_read(&tomoyo_policy_manager_list_lock);
1157         if (found)
1158                 return true;
1159         exe = tomoyo_get_exe();
1160         if (!exe)
1161                 return false;
1162         down_read(&tomoyo_policy_manager_list_lock);
1163         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1164                 if (!ptr->is_deleted && !ptr->is_domain
1165                     && !strcmp(exe, ptr->manager->name)) {
1166                         found = true;
1167                         break;
1168                 }
1169         }
1170         up_read(&tomoyo_policy_manager_list_lock);
1171         if (!found) { /* Reduce error messages. */
1172                 static pid_t last_pid;
1173                 const pid_t pid = current->pid;
1174                 if (last_pid != pid) {
1175                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1176                                "update policies.\n", domainname->name, exe);
1177                         last_pid = pid;
1178                 }
1179         }
1180         tomoyo_free(exe);
1181         return found;
1182 }
1183
1184 /**
1185  * tomoyo_is_select_one - Parse select command.
1186  *
1187  * @head: Pointer to "struct tomoyo_io_buffer".
1188  * @data: String to parse.
1189  *
1190  * Returns true on success, false otherwise.
1191  */
1192 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1193                                  const char *data)
1194 {
1195         unsigned int pid;
1196         struct tomoyo_domain_info *domain = NULL;
1197
1198         if (sscanf(data, "pid=%u", &pid) == 1) {
1199                 struct task_struct *p;
1200                 /***** CRITICAL SECTION START *****/
1201                 read_lock(&tasklist_lock);
1202                 p = find_task_by_vpid(pid);
1203                 if (p)
1204                         domain = tomoyo_real_domain(p);
1205                 read_unlock(&tasklist_lock);
1206                 /***** CRITICAL SECTION END *****/
1207         } else if (!strncmp(data, "domain=", 7)) {
1208                 if (tomoyo_is_domain_def(data + 7)) {
1209                         down_read(&tomoyo_domain_list_lock);
1210                         domain = tomoyo_find_domain(data + 7);
1211                         up_read(&tomoyo_domain_list_lock);
1212                 }
1213         } else
1214                 return false;
1215         head->write_var1 = domain;
1216         /* Accessing read_buf is safe because head->io_sem is held. */
1217         if (!head->read_buf)
1218                 return true; /* Do nothing if open(O_WRONLY). */
1219         head->read_avail = 0;
1220         tomoyo_io_printf(head, "# select %s\n", data);
1221         head->read_single_domain = true;
1222         head->read_eof = !domain;
1223         if (domain) {
1224                 struct tomoyo_domain_info *d;
1225                 head->read_var1 = NULL;
1226                 down_read(&tomoyo_domain_list_lock);
1227                 list_for_each_entry(d, &tomoyo_domain_list, list) {
1228                         if (d == domain)
1229                                 break;
1230                         head->read_var1 = &d->list;
1231                 }
1232                 up_read(&tomoyo_domain_list_lock);
1233                 head->read_var2 = NULL;
1234                 head->read_bit = 0;
1235                 head->read_step = 0;
1236                 if (domain->is_deleted)
1237                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1238         }
1239         return true;
1240 }
1241
1242 /**
1243  * tomoyo_write_domain_policy - Write domain policy.
1244  *
1245  * @head: Pointer to "struct tomoyo_io_buffer".
1246  *
1247  * Returns 0 on success, negative value otherwise.
1248  */
1249 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1250 {
1251         char *data = head->write_buf;
1252         struct tomoyo_domain_info *domain = head->write_var1;
1253         bool is_delete = false;
1254         bool is_select = false;
1255         bool is_undelete = false;
1256         unsigned int profile;
1257
1258         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1259                 is_delete = true;
1260         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1261                 is_select = true;
1262         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_UNDELETE))
1263                 is_undelete = true;
1264         if (is_select && tomoyo_is_select_one(head, data))
1265                 return 0;
1266         /* Don't allow updating policies by non manager programs. */
1267         if (!tomoyo_is_policy_manager())
1268                 return -EPERM;
1269         if (tomoyo_is_domain_def(data)) {
1270                 domain = NULL;
1271                 if (is_delete)
1272                         tomoyo_delete_domain(data);
1273                 else if (is_select) {
1274                         down_read(&tomoyo_domain_list_lock);
1275                         domain = tomoyo_find_domain(data);
1276                         up_read(&tomoyo_domain_list_lock);
1277                 } else if (is_undelete)
1278                         domain = tomoyo_undelete_domain(data);
1279                 else
1280                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1281                 head->write_var1 = domain;
1282                 return 0;
1283         }
1284         if (!domain)
1285                 return -EINVAL;
1286
1287         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1288             && profile < TOMOYO_MAX_PROFILES) {
1289                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1290                         domain->profile = (u8) profile;
1291                 return 0;
1292         }
1293         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1294                 tomoyo_set_domain_flag(domain, is_delete,
1295                                TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
1296                 return 0;
1297         }
1298         return tomoyo_write_file_policy(data, domain, is_delete);
1299 }
1300
1301 /**
1302  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1303  *
1304  * @head: Pointer to "struct tomoyo_io_buffer".
1305  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1306  *
1307  * Returns true on success, false otherwise.
1308  */
1309 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1310                                          struct tomoyo_single_path_acl_record *
1311                                          ptr)
1312 {
1313         int pos;
1314         u8 bit;
1315         const char *atmark = "";
1316         const char *filename;
1317         const u16 perm = ptr->perm;
1318
1319         filename = ptr->filename->name;
1320         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1321              bit++) {
1322                 const char *msg;
1323                 if (!(perm & (1 << bit)))
1324                         continue;
1325                 /* Print "read/write" instead of "read" and "write". */
1326                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1327                      bit == TOMOYO_TYPE_WRITE_ACL)
1328                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1329                         continue;
1330                 msg = tomoyo_sp2keyword(bit);
1331                 pos = head->read_avail;
1332                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1333                                       atmark, filename))
1334                         goto out;
1335         }
1336         head->read_bit = 0;
1337         return true;
1338  out:
1339         head->read_bit = bit;
1340         head->read_avail = pos;
1341         return false;
1342 }
1343
1344 /**
1345  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1346  *
1347  * @head: Pointer to "struct tomoyo_io_buffer".
1348  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1349  *
1350  * Returns true on success, false otherwise.
1351  */
1352 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1353                                          struct tomoyo_double_path_acl_record *
1354                                          ptr)
1355 {
1356         int pos;
1357         const char *atmark1 = "";
1358         const char *atmark2 = "";
1359         const char *filename1;
1360         const char *filename2;
1361         const u8 perm = ptr->perm;
1362         u8 bit;
1363
1364         filename1 = ptr->filename1->name;
1365         filename2 = ptr->filename2->name;
1366         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1367              bit++) {
1368                 const char *msg;
1369                 if (!(perm & (1 << bit)))
1370                         continue;
1371                 msg = tomoyo_dp2keyword(bit);
1372                 pos = head->read_avail;
1373                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1374                                       atmark1, filename1, atmark2, filename2))
1375                         goto out;
1376         }
1377         head->read_bit = 0;
1378         return true;
1379  out:
1380         head->read_bit = bit;
1381         head->read_avail = pos;
1382         return false;
1383 }
1384
1385 /**
1386  * tomoyo_print_entry - Print an ACL entry.
1387  *
1388  * @head: Pointer to "struct tomoyo_io_buffer".
1389  * @ptr:  Pointer to an ACL entry.
1390  *
1391  * Returns true on success, false otherwise.
1392  */
1393 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1394                                struct tomoyo_acl_info *ptr)
1395 {
1396         const u8 acl_type = tomoyo_acl_type2(ptr);
1397
1398         if (acl_type & TOMOYO_ACL_DELETED)
1399                 return true;
1400         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1401                 struct tomoyo_single_path_acl_record *acl
1402                         = container_of(ptr,
1403                                        struct tomoyo_single_path_acl_record,
1404                                        head);
1405                 return tomoyo_print_single_path_acl(head, acl);
1406         }
1407         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1408                 struct tomoyo_double_path_acl_record *acl
1409                         = container_of(ptr,
1410                                        struct tomoyo_double_path_acl_record,
1411                                        head);
1412                 return tomoyo_print_double_path_acl(head, acl);
1413         }
1414         BUG(); /* This must not happen. */
1415         return false;
1416 }
1417
1418 /**
1419  * tomoyo_read_domain_policy - Read domain policy.
1420  *
1421  * @head: Pointer to "struct tomoyo_io_buffer".
1422  *
1423  * Returns 0.
1424  */
1425 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1426 {
1427         struct list_head *dpos;
1428         struct list_head *apos;
1429         bool done = true;
1430
1431         if (head->read_eof)
1432                 return 0;
1433         if (head->read_step == 0)
1434                 head->read_step = 1;
1435         down_read(&tomoyo_domain_list_lock);
1436         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1437                 struct tomoyo_domain_info *domain;
1438                 const char *quota_exceeded = "";
1439                 const char *transition_failed = "";
1440                 const char *ignore_global_allow_read = "";
1441                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1442                 if (head->read_step != 1)
1443                         goto acl_loop;
1444                 if (domain->is_deleted && !head->read_single_domain)
1445                         continue;
1446                 /* Print domainname and flags. */
1447                 if (domain->quota_warned)
1448                         quota_exceeded = "quota_exceeded\n";
1449                 if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
1450                         transition_failed = "transition_failed\n";
1451                 if (domain->flags &
1452                     TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
1453                         ignore_global_allow_read
1454                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1455                 if (!tomoyo_io_printf(head,
1456                                       "%s\n" TOMOYO_KEYWORD_USE_PROFILE "%u\n"
1457                                       "%s%s%s\n", domain->domainname->name,
1458                                       domain->profile, quota_exceeded,
1459                                       transition_failed,
1460                                       ignore_global_allow_read)) {
1461                         done = false;
1462                         break;
1463                 }
1464                 head->read_step = 2;
1465 acl_loop:
1466                 if (head->read_step == 3)
1467                         goto tail_mark;
1468                 /* Print ACL entries in the domain. */
1469                 down_read(&tomoyo_domain_acl_info_list_lock);
1470                 list_for_each_cookie(apos, head->read_var2,
1471                                       &domain->acl_info_list) {
1472                         struct tomoyo_acl_info *ptr
1473                                 = list_entry(apos, struct tomoyo_acl_info,
1474                                               list);
1475                         if (!tomoyo_print_entry(head, ptr)) {
1476                                 done = false;
1477                                 break;
1478                         }
1479                 }
1480                 up_read(&tomoyo_domain_acl_info_list_lock);
1481                 if (!done)
1482                         break;
1483                 head->read_step = 3;
1484 tail_mark:
1485                 if (!tomoyo_io_printf(head, "\n")) {
1486                         done = false;
1487                         break;
1488                 }
1489                 head->read_step = 1;
1490                 if (head->read_single_domain)
1491                         break;
1492         }
1493         up_read(&tomoyo_domain_list_lock);
1494         head->read_eof = done;
1495         return 0;
1496 }
1497
1498 /**
1499  * tomoyo_write_domain_profile - Assign profile for specified domain.
1500  *
1501  * @head: Pointer to "struct tomoyo_io_buffer".
1502  *
1503  * Returns 0 on success, -EINVAL otherwise.
1504  *
1505  * This is equivalent to doing
1506  *
1507  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1508  *     /usr/lib/ccs/loadpolicy -d
1509  */
1510 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1511 {
1512         char *data = head->write_buf;
1513         char *cp = strchr(data, ' ');
1514         struct tomoyo_domain_info *domain;
1515         unsigned long profile;
1516
1517         if (!cp)
1518                 return -EINVAL;
1519         *cp = '\0';
1520         down_read(&tomoyo_domain_list_lock);
1521         domain = tomoyo_find_domain(cp + 1);
1522         up_read(&tomoyo_domain_list_lock);
1523         if (strict_strtoul(data, 10, &profile))
1524                 return -EINVAL;
1525         if (domain && profile < TOMOYO_MAX_PROFILES
1526             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1527                 domain->profile = (u8) profile;
1528         return 0;
1529 }
1530
1531 /**
1532  * tomoyo_read_domain_profile - Read only domainname and profile.
1533  *
1534  * @head: Pointer to "struct tomoyo_io_buffer".
1535  *
1536  * Returns list of profile number and domainname pairs.
1537  *
1538  * This is equivalent to doing
1539  *
1540  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1541  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1542  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1543  *     print $2 " " domainname; domainname = ""; } } ; '
1544  */
1545 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1546 {
1547         struct list_head *pos;
1548         bool done = true;
1549
1550         if (head->read_eof)
1551                 return 0;
1552         down_read(&tomoyo_domain_list_lock);
1553         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1554                 struct tomoyo_domain_info *domain;
1555                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1556                 if (domain->is_deleted)
1557                         continue;
1558                 if (!tomoyo_io_printf(head, "%u %s\n", domain->profile,
1559                                       domain->domainname->name)) {
1560                         done = false;
1561                         break;
1562                 }
1563         }
1564         up_read(&tomoyo_domain_list_lock);
1565         head->read_eof = done;
1566         return 0;
1567 }
1568
1569 /**
1570  * tomoyo_write_pid: Specify PID to obtain domainname.
1571  *
1572  * @head: Pointer to "struct tomoyo_io_buffer".
1573  *
1574  * Returns 0.
1575  */
1576 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1577 {
1578         unsigned long pid;
1579         /* No error check. */
1580         strict_strtoul(head->write_buf, 10, &pid);
1581         head->read_step = (int) pid;
1582         head->read_eof = false;
1583         return 0;
1584 }
1585
1586 /**
1587  * tomoyo_read_pid - Get domainname of the specified PID.
1588  *
1589  * @head: Pointer to "struct tomoyo_io_buffer".
1590  *
1591  * Returns the domainname which the specified PID is in on success,
1592  * empty string otherwise.
1593  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1594  * using read()/write() interface rather than sysctl() interface.
1595  */
1596 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1597 {
1598         if (head->read_avail == 0 && !head->read_eof) {
1599                 const int pid = head->read_step;
1600                 struct task_struct *p;
1601                 struct tomoyo_domain_info *domain = NULL;
1602                 /***** CRITICAL SECTION START *****/
1603                 read_lock(&tasklist_lock);
1604                 p = find_task_by_vpid(pid);
1605                 if (p)
1606                         domain = tomoyo_real_domain(p);
1607                 read_unlock(&tasklist_lock);
1608                 /***** CRITICAL SECTION END *****/
1609                 if (domain)
1610                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1611                                          domain->domainname->name);
1612                 head->read_eof = true;
1613         }
1614         return 0;
1615 }
1616
1617 /**
1618  * tomoyo_write_exception_policy - Write exception policy.
1619  *
1620  * @head: Pointer to "struct tomoyo_io_buffer".
1621  *
1622  * Returns 0 on success, negative value otherwise.
1623  */
1624 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1625 {
1626         char *data = head->write_buf;
1627         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1628
1629         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1630                 return tomoyo_write_domain_keeper_policy(data, false,
1631                                                          is_delete);
1632         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1633                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1634         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1635                 return tomoyo_write_domain_initializer_policy(data, false,
1636                                                               is_delete);
1637         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1638                 return tomoyo_write_domain_initializer_policy(data, true,
1639                                                               is_delete);
1640         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1641                 return tomoyo_write_alias_policy(data, is_delete);
1642         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1643                 return tomoyo_write_globally_readable_policy(data, is_delete);
1644         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1645                 return tomoyo_write_pattern_policy(data, is_delete);
1646         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1647                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1648         return -EINVAL;
1649 }
1650
1651 /**
1652  * tomoyo_read_exception_policy - Read exception policy.
1653  *
1654  * @head: Pointer to "struct tomoyo_io_buffer".
1655  *
1656  * Returns 0 on success, -EINVAL otherwise.
1657  */
1658 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1659 {
1660         if (!head->read_eof) {
1661                 switch (head->read_step) {
1662                 case 0:
1663                         head->read_var2 = NULL;
1664                         head->read_step = 1;
1665                 case 1:
1666                         if (!tomoyo_read_domain_keeper_policy(head))
1667                                 break;
1668                         head->read_var2 = NULL;
1669                         head->read_step = 2;
1670                 case 2:
1671                         if (!tomoyo_read_globally_readable_policy(head))
1672                                 break;
1673                         head->read_var2 = NULL;
1674                         head->read_step = 3;
1675                 case 3:
1676                         head->read_var2 = NULL;
1677                         head->read_step = 4;
1678                 case 4:
1679                         if (!tomoyo_read_domain_initializer_policy(head))
1680                                 break;
1681                         head->read_var2 = NULL;
1682                         head->read_step = 5;
1683                 case 5:
1684                         if (!tomoyo_read_alias_policy(head))
1685                                 break;
1686                         head->read_var2 = NULL;
1687                         head->read_step = 6;
1688                 case 6:
1689                         head->read_var2 = NULL;
1690                         head->read_step = 7;
1691                 case 7:
1692                         if (!tomoyo_read_file_pattern(head))
1693                                 break;
1694                         head->read_var2 = NULL;
1695                         head->read_step = 8;
1696                 case 8:
1697                         if (!tomoyo_read_no_rewrite_policy(head))
1698                                 break;
1699                         head->read_var2 = NULL;
1700                         head->read_step = 9;
1701                 case 9:
1702                         head->read_eof = true;
1703                         break;
1704                 default:
1705                         return -EINVAL;
1706                 }
1707         }
1708         return 0;
1709 }
1710
1711 /* path to policy loader */
1712 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1713
1714 /**
1715  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1716  *
1717  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1718  */
1719 static bool tomoyo_policy_loader_exists(void)
1720 {
1721         /*
1722          * Don't activate MAC if the policy loader doesn't exist.
1723          * If the initrd includes /sbin/init but real-root-dev has not
1724          * mounted on / yet, activating MAC will block the system since
1725          * policies are not loaded yet.
1726          * Thus, let do_execve() call this function everytime.
1727          */
1728         struct nameidata nd;
1729
1730         if (path_lookup(tomoyo_loader, LOOKUP_FOLLOW, &nd)) {
1731                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1732                        "since %s doesn't exist.\n", tomoyo_loader);
1733                 return false;
1734         }
1735         path_put(&nd.path);
1736         return true;
1737 }
1738
1739 /**
1740  * tomoyo_load_policy - Run external policy loader to load policy.
1741  *
1742  * @filename: The program about to start.
1743  *
1744  * This function checks whether @filename is /sbin/init , and if so
1745  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1746  * and then continues invocation of /sbin/init.
1747  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1748  * writes to /sys/kernel/security/tomoyo/ interfaces.
1749  *
1750  * Returns nothing.
1751  */
1752 void tomoyo_load_policy(const char *filename)
1753 {
1754         char *argv[2];
1755         char *envp[3];
1756
1757         if (tomoyo_policy_loaded)
1758                 return;
1759         /*
1760          * Check filename is /sbin/init or /sbin/tomoyo-start.
1761          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1762          * be passed.
1763          * You can create /sbin/tomoyo-start by
1764          * "ln -s /bin/true /sbin/tomoyo-start".
1765          */
1766         if (strcmp(filename, "/sbin/init") &&
1767             strcmp(filename, "/sbin/tomoyo-start"))
1768                 return;
1769         if (!tomoyo_policy_loader_exists())
1770                 return;
1771
1772         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1773                tomoyo_loader);
1774         argv[0] = (char *) tomoyo_loader;
1775         argv[1] = NULL;
1776         envp[0] = "HOME=/";
1777         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1778         envp[2] = NULL;
1779         call_usermodehelper(argv[0], argv, envp, 1);
1780
1781         printk(KERN_INFO "TOMOYO: 2.2.0-pre   2009/02/01\n");
1782         printk(KERN_INFO "Mandatory Access Control activated.\n");
1783         tomoyo_policy_loaded = true;
1784         { /* Check all profiles currently assigned to domains are defined. */
1785                 struct tomoyo_domain_info *domain;
1786                 down_read(&tomoyo_domain_list_lock);
1787                 list_for_each_entry(domain, &tomoyo_domain_list, list) {
1788                         const u8 profile = domain->profile;
1789                         if (tomoyo_profile_ptr[profile])
1790                                 continue;
1791                         panic("Profile %u (used by '%s') not defined.\n",
1792                               profile, domain->domainname->name);
1793                 }
1794                 up_read(&tomoyo_domain_list_lock);
1795         }
1796 }
1797
1798 /**
1799  * tomoyo_read_version: Get version.
1800  *
1801  * @head: Pointer to "struct tomoyo_io_buffer".
1802  *
1803  * Returns version information.
1804  */
1805 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1806 {
1807         if (!head->read_eof) {
1808                 tomoyo_io_printf(head, "2.2.0-pre");
1809                 head->read_eof = true;
1810         }
1811         return 0;
1812 }
1813
1814 /**
1815  * tomoyo_read_self_domain - Get the current process's domainname.
1816  *
1817  * @head: Pointer to "struct tomoyo_io_buffer".
1818  *
1819  * Returns the current process's domainname.
1820  */
1821 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1822 {
1823         if (!head->read_eof) {
1824                 /*
1825                  * tomoyo_domain()->domainname != NULL
1826                  * because every process belongs to a domain and
1827                  * the domain's name cannot be NULL.
1828                  */
1829                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1830                 head->read_eof = true;
1831         }
1832         return 0;
1833 }
1834
1835 /**
1836  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1837  *
1838  * @type: Type of interface.
1839  * @file: Pointer to "struct file".
1840  *
1841  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1842  */
1843 static int tomoyo_open_control(const u8 type, struct file *file)
1844 {
1845         struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
1846
1847         if (!head)
1848                 return -ENOMEM;
1849         mutex_init(&head->io_sem);
1850         switch (type) {
1851         case TOMOYO_DOMAINPOLICY:
1852                 /* /sys/kernel/security/tomoyo/domain_policy */
1853                 head->write = tomoyo_write_domain_policy;
1854                 head->read = tomoyo_read_domain_policy;
1855                 break;
1856         case TOMOYO_EXCEPTIONPOLICY:
1857                 /* /sys/kernel/security/tomoyo/exception_policy */
1858                 head->write = tomoyo_write_exception_policy;
1859                 head->read = tomoyo_read_exception_policy;
1860                 break;
1861         case TOMOYO_SELFDOMAIN:
1862                 /* /sys/kernel/security/tomoyo/self_domain */
1863                 head->read = tomoyo_read_self_domain;
1864                 break;
1865         case TOMOYO_DOMAIN_STATUS:
1866                 /* /sys/kernel/security/tomoyo/.domain_status */
1867                 head->write = tomoyo_write_domain_profile;
1868                 head->read = tomoyo_read_domain_profile;
1869                 break;
1870         case TOMOYO_PROCESS_STATUS:
1871                 /* /sys/kernel/security/tomoyo/.process_status */
1872                 head->write = tomoyo_write_pid;
1873                 head->read = tomoyo_read_pid;
1874                 break;
1875         case TOMOYO_VERSION:
1876                 /* /sys/kernel/security/tomoyo/version */
1877                 head->read = tomoyo_read_version;
1878                 head->readbuf_size = 128;
1879                 break;
1880         case TOMOYO_MEMINFO:
1881                 /* /sys/kernel/security/tomoyo/meminfo */
1882                 head->write = tomoyo_write_memory_quota;
1883                 head->read = tomoyo_read_memory_counter;
1884                 head->readbuf_size = 512;
1885                 break;
1886         case TOMOYO_PROFILE:
1887                 /* /sys/kernel/security/tomoyo/profile */
1888                 head->write = tomoyo_write_profile;
1889                 head->read = tomoyo_read_profile;
1890                 break;
1891         case TOMOYO_MANAGER:
1892                 /* /sys/kernel/security/tomoyo/manager */
1893                 head->write = tomoyo_write_manager_policy;
1894                 head->read = tomoyo_read_manager_policy;
1895                 break;
1896         }
1897         if (!(file->f_mode & FMODE_READ)) {
1898                 /*
1899                  * No need to allocate read_buf since it is not opened
1900                  * for reading.
1901                  */
1902                 head->read = NULL;
1903         } else {
1904                 if (!head->readbuf_size)
1905                         head->readbuf_size = 4096 * 2;
1906                 head->read_buf = tomoyo_alloc(head->readbuf_size);
1907                 if (!head->read_buf) {
1908                         tomoyo_free(head);
1909                         return -ENOMEM;
1910                 }
1911         }
1912         if (!(file->f_mode & FMODE_WRITE)) {
1913                 /*
1914                  * No need to allocate write_buf since it is not opened
1915                  * for writing.
1916                  */
1917                 head->write = NULL;
1918         } else if (head->write) {
1919                 head->writebuf_size = 4096 * 2;
1920                 head->write_buf = tomoyo_alloc(head->writebuf_size);
1921                 if (!head->write_buf) {
1922                         tomoyo_free(head->read_buf);
1923                         tomoyo_free(head);
1924                         return -ENOMEM;
1925                 }
1926         }
1927         file->private_data = head;
1928         /*
1929          * Call the handler now if the file is
1930          * /sys/kernel/security/tomoyo/self_domain
1931          * so that the user can use
1932          * cat < /sys/kernel/security/tomoyo/self_domain"
1933          * to know the current process's domainname.
1934          */
1935         if (type == TOMOYO_SELFDOMAIN)
1936                 tomoyo_read_control(file, NULL, 0);
1937         return 0;
1938 }
1939
1940 /**
1941  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1942  *
1943  * @file:       Pointer to "struct file".
1944  * @buffer:     Poiner to buffer to write to.
1945  * @buffer_len: Size of @buffer.
1946  *
1947  * Returns bytes read on success, negative value otherwise.
1948  */
1949 static int tomoyo_read_control(struct file *file, char __user *buffer,
1950                                const int buffer_len)
1951 {
1952         int len = 0;
1953         struct tomoyo_io_buffer *head = file->private_data;
1954         char *cp;
1955
1956         if (!head->read)
1957                 return -ENOSYS;
1958         if (mutex_lock_interruptible(&head->io_sem))
1959                 return -EINTR;
1960         /* Call the policy handler. */
1961         len = head->read(head);
1962         if (len < 0)
1963                 goto out;
1964         /* Write to buffer. */
1965         len = head->read_avail;
1966         if (len > buffer_len)
1967                 len = buffer_len;
1968         if (!len)
1969                 goto out;
1970         /* head->read_buf changes by some functions. */
1971         cp = head->read_buf;
1972         if (copy_to_user(buffer, cp, len)) {
1973                 len = -EFAULT;
1974                 goto out;
1975         }
1976         head->read_avail -= len;
1977         memmove(cp, cp + len, head->read_avail);
1978  out:
1979         mutex_unlock(&head->io_sem);
1980         return len;
1981 }
1982
1983 /**
1984  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
1985  *
1986  * @file:       Pointer to "struct file".
1987  * @buffer:     Pointer to buffer to read from.
1988  * @buffer_len: Size of @buffer.
1989  *
1990  * Returns @buffer_len on success, negative value otherwise.
1991  */
1992 static int tomoyo_write_control(struct file *file, const char __user *buffer,
1993                                 const int buffer_len)
1994 {
1995         struct tomoyo_io_buffer *head = file->private_data;
1996         int error = buffer_len;
1997         int avail_len = buffer_len;
1998         char *cp0 = head->write_buf;
1999
2000         if (!head->write)
2001                 return -ENOSYS;
2002         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2003                 return -EFAULT;
2004         /* Don't allow updating policies by non manager programs. */
2005         if (head->write != tomoyo_write_pid &&
2006             head->write != tomoyo_write_domain_policy &&
2007             !tomoyo_is_policy_manager())
2008                 return -EPERM;
2009         if (mutex_lock_interruptible(&head->io_sem))
2010                 return -EINTR;
2011         /* Read a line and dispatch it to the policy handler. */
2012         while (avail_len > 0) {
2013                 char c;
2014                 if (head->write_avail >= head->writebuf_size - 1) {
2015                         error = -ENOMEM;
2016                         break;
2017                 } else if (get_user(c, buffer)) {
2018                         error = -EFAULT;
2019                         break;
2020                 }
2021                 buffer++;
2022                 avail_len--;
2023                 cp0[head->write_avail++] = c;
2024                 if (c != '\n')
2025                         continue;
2026                 cp0[head->write_avail - 1] = '\0';
2027                 head->write_avail = 0;
2028                 tomoyo_normalize_line(cp0);
2029                 head->write(head);
2030         }
2031         mutex_unlock(&head->io_sem);
2032         return error;
2033 }
2034
2035 /**
2036  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2037  *
2038  * @file: Pointer to "struct file".
2039  *
2040  * Releases memory and returns 0.
2041  */
2042 static int tomoyo_close_control(struct file *file)
2043 {
2044         struct tomoyo_io_buffer *head = file->private_data;
2045
2046         /* Release memory used for policy I/O. */
2047         tomoyo_free(head->read_buf);
2048         head->read_buf = NULL;
2049         tomoyo_free(head->write_buf);
2050         head->write_buf = NULL;
2051         tomoyo_free(head);
2052         head = NULL;
2053         file->private_data = NULL;
2054         return 0;
2055 }
2056
2057 /**
2058  * tomoyo_alloc_acl_element - Allocate permanent memory for ACL entry.
2059  *
2060  * @acl_type:  Type of ACL entry.
2061  *
2062  * Returns pointer to the ACL entry on success, NULL otherwise.
2063  */
2064 void *tomoyo_alloc_acl_element(const u8 acl_type)
2065 {
2066         int len;
2067         struct tomoyo_acl_info *ptr;
2068
2069         switch (acl_type) {
2070         case TOMOYO_TYPE_SINGLE_PATH_ACL:
2071                 len = sizeof(struct tomoyo_single_path_acl_record);
2072                 break;
2073         case TOMOYO_TYPE_DOUBLE_PATH_ACL:
2074                 len = sizeof(struct tomoyo_double_path_acl_record);
2075                 break;
2076         default:
2077                 return NULL;
2078         }
2079         ptr = tomoyo_alloc_element(len);
2080         if (!ptr)
2081                 return NULL;
2082         ptr->type = acl_type;
2083         return ptr;
2084 }
2085
2086 /**
2087  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2088  *
2089  * @inode: Pointer to "struct inode".
2090  * @file:  Pointer to "struct file".
2091  *
2092  * Returns 0 on success, negative value otherwise.
2093  */
2094 static int tomoyo_open(struct inode *inode, struct file *file)
2095 {
2096         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2097                 - ((u8 *) NULL);
2098         return tomoyo_open_control(key, file);
2099 }
2100
2101 /**
2102  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2103  *
2104  * @inode: Pointer to "struct inode".
2105  * @file:  Pointer to "struct file".
2106  *
2107  * Returns 0 on success, negative value otherwise.
2108  */
2109 static int tomoyo_release(struct inode *inode, struct file *file)
2110 {
2111         return tomoyo_close_control(file);
2112 }
2113
2114 /**
2115  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2116  *
2117  * @file:  Pointer to "struct file".
2118  * @buf:   Pointer to buffer.
2119  * @count: Size of @buf.
2120  * @ppos:  Unused.
2121  *
2122  * Returns bytes read on success, negative value otherwise.
2123  */
2124 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2125                            loff_t *ppos)
2126 {
2127         return tomoyo_read_control(file, buf, count);
2128 }
2129
2130 /**
2131  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2132  *
2133  * @file:  Pointer to "struct file".
2134  * @buf:   Pointer to buffer.
2135  * @count: Size of @buf.
2136  * @ppos:  Unused.
2137  *
2138  * Returns @count on success, negative value otherwise.
2139  */
2140 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2141                             size_t count, loff_t *ppos)
2142 {
2143         return tomoyo_write_control(file, buf, count);
2144 }
2145
2146 /* Operations for /sys/kernel/security/tomoyo/ interface. */
2147 static const struct file_operations tomoyo_operations = {
2148         .open    = tomoyo_open,
2149         .release = tomoyo_release,
2150         .read    = tomoyo_read,
2151         .write   = tomoyo_write,
2152 };
2153
2154 /**
2155  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2156  *
2157  * @name:   The name of the interface file.
2158  * @mode:   The permission of the interface file.
2159  * @parent: The parent directory.
2160  * @key:    Type of interface.
2161  *
2162  * Returns nothing.
2163  */
2164 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2165                                        struct dentry *parent, const u8 key)
2166 {
2167         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2168                                &tomoyo_operations);
2169 }
2170
2171 /**
2172  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2173  *
2174  * Returns 0.
2175  */
2176 static int __init tomoyo_initerface_init(void)
2177 {
2178         struct dentry *tomoyo_dir;
2179
2180         /* Don't create securityfs entries unless registered. */
2181         if (current_cred()->security != &tomoyo_kernel_domain)
2182                 return 0;
2183
2184         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2185         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2186                             TOMOYO_DOMAINPOLICY);
2187         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2188                             TOMOYO_EXCEPTIONPOLICY);
2189         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2190                             TOMOYO_SELFDOMAIN);
2191         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2192                             TOMOYO_DOMAIN_STATUS);
2193         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2194                             TOMOYO_PROCESS_STATUS);
2195         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2196                             TOMOYO_MEMINFO);
2197         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2198                             TOMOYO_PROFILE);
2199         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2200                             TOMOYO_MANAGER);
2201         tomoyo_create_entry("version",          0400, tomoyo_dir,
2202                             TOMOYO_VERSION);
2203         return 0;
2204 }
2205
2206 fs_initcall(tomoyo_initerface_init);