security/tomoyo/common.c

   1 /*
   2  * security/tomoyo/common.c
   3  *
   4  * Common functions for TOMOYO.
   5  *
   6  * Copyright (C) 2005-2009  NTT DATA CORPORATION
   7  *
   8  * Version: 2.2.0   2009/04/01
   9  *
  10  */
  11
  12 #include <linux/uaccess.h>
  13 #include <linux/security.h>
  14 #include <linux/hardirq.h>
  15 #include "realpath.h"
  16 #include "common.h"
  17 #include "tomoyo.h"
  18
  19 /* 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 /*
  32  * tomoyo_control_array is a static data which contains
  33  *
  34  *  (1) functionality name used by /sys/kernel/security/tomoyo/profile .
  35  *  (2) initial values for "struct tomoyo_profile".
  36  *  (3) max values for "struct tomoyo_profile".
  37  */
  38 static struct {
  39         const char *keyword;
  40         unsigned int current_value;
  41         const unsigned int max_value;
  42 } tomoyo_control_array[TOMOYO_MAX_CONTROL_INDEX] = {
  43         [TOMOYO_MAC_FOR_FILE]     = { "MAC_FOR_FILE",        0,       3 },
  44         [TOMOYO_MAX_ACCEPT_ENTRY] = { "MAX_ACCEPT_ENTRY", 2048, INT_MAX },
  45         [TOMOYO_VERBOSE]          = { "TOMOYO_VERBOSE",      1,       1 },
  46 };
  47
  48 /*
  49  * tomoyo_profile is a structure which is used for holding the mode of access
  50  * controls. TOMOYO has 4 modes: disabled, learning, permissive, enforcing.
  51  * An administrator can define up to 256 profiles.
  52  * The ->profile of "struct tomoyo_domain_info" is used for remembering
  53  * the profile's number (0 - 255) assigned to that domain.
  54  */
  55 static struct tomoyo_profile {
  56         unsigned int value[TOMOYO_MAX_CONTROL_INDEX];
  57         const struct tomoyo_path_info *comment;
  58 } *tomoyo_profile_ptr[TOMOYO_MAX_PROFILES];
  59
  60 /* Permit policy management by non-root user? */
  61 static bool tomoyo_manage_by_non_root;
  62
  63 /* Utility functions. */
  64
  65 /* Open operation for /sys/kernel/security/tomoyo/ interface. */
  66 static int tomoyo_open_control(const u8 type, struct file *file);
  67 /* Close /sys/kernel/security/tomoyo/ interface. */
  68 static int tomoyo_close_control(struct file *file);
  69 /* Read operation for /sys/kernel/security/tomoyo/ interface. */
  70 static int tomoyo_read_control(struct file *file, char __user *buffer,
  71                                const int buffer_len);
  72 /* Write operation for /sys/kernel/security/tomoyo/ interface. */
  73 static int tomoyo_write_control(struct file *file, const char __user *buffer,
  74                                 const int buffer_len);
  75
  76 /**
  77  * tomoyo_is_byte_range - Check whether the string isa \ooo style octal value.
  78  *
  79  * @str: Pointer to the string.
  80  *
  81  * Returns true if @str is a \ooo style octal value, false otherwise.
  82  *
  83  * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
  84  * This function verifies that \ooo is in valid range.
  85  */
  86 static inline bool tomoyo_is_byte_range(const char *str)
  87 {
  88         return *str >= '0' && *str++ <= '3' &&
  89                 *str >= '0' && *str++ <= '7' &&
  90                 *str >= '0' && *str <= '7';
  91 }
  92
  93 /**
  94  * tomoyo_is_alphabet_char - Check whether the character is an alphabet.
  95  *
  96  * @c: The character to check.
  97  *
  98  * Returns true if @c is an alphabet character, false otherwise.
  99  */
 100 static inline bool tomoyo_is_alphabet_char(const char c)
 101 {
 102         return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
 103 }
 104
 105 /**
 106  * tomoyo_make_byte - Make byte value from three octal characters.
 107  *
 108  * @c1: The first character.
 109  * @c2: The second character.
 110  * @c3: The third character.
 111  *
 112  * Returns byte value.
 113  */
 114 static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
 115 {
 116         return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
 117 }
 118
 119 /**
 120  * tomoyo_str_starts - Check whether the given string starts with the given keyword.
 121  *
 122  * @src:  Pointer to pointer to the string.
 123  * @find: Pointer to the keyword.
 124  *
 125  * Returns true if @src starts with @find, false otherwise.
 126  *
 127  * The @src is updated to point the first character after the @find
 128  * if @src starts with @find.
 129  */
 130 static bool tomoyo_str_starts(char **src, const char *find)
 131 {
 132         const int len = strlen(find);
 133         char *tmp = *src;
 134
 135         if (strncmp(tmp, find, len))
 136                 return false;
 137         tmp += len;
 138         *src = tmp;
 139         return true;
 140 }
 141
 142 /**
 143  * tomoyo_normalize_line - Format string.
 144  *
 145  * @buffer: The line to normalize.
 146  *
 147  * Leading and trailing whitespaces are removed.
 148  * Multiple whitespaces are packed into single space.
 149  *
 150  * Returns nothing.
 151  */
 152 static void tomoyo_normalize_line(unsigned char *buffer)
 153 {
 154         unsigned char *sp = buffer;
 155         unsigned char *dp = buffer;
 156         bool first = true;
 157
 158         while (tomoyo_is_invalid(*sp))
 159                 sp++;
 160         while (*sp) {
 161                 if (!first)
 162                         *dp++ = ' ';
 163                 first = false;
 164                 while (tomoyo_is_valid(*sp))
 165                         *dp++ = *sp++;
 166                 while (tomoyo_is_invalid(*sp))
 167                         sp++;
 168         }
 169         *dp = '\0';
 170 }
 171
 172 /**
 173  * tomoyo_is_correct_path - Validate a pathname.
 174  * @filename:     The pathname to check.
 175  * @start_type:   Should the pathname start with '/'?
 176  *                1 = must / -1 = must not / 0 = don't care
 177  * @pattern_type: Can the pathname contain a wildcard?
 178  *                1 = must / -1 = must not / 0 = don't care
 179  * @end_type:     Should the pathname end with '/'?
 180  *                1 = must / -1 = must not / 0 = don't care
 181  * @function:     The name of function calling me.
 182  *
 183  * Check whether the given filename follows the naming rules.
 184  * Returns true if @filename follows the naming rules, false otherwise.
 185  */
 186 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 187                             const s8 pattern_type, const s8 end_type,
 188                             const char *function)
 189 {
 190         bool contains_pattern = false;
 191         unsigned char c;
 192         unsigned char d;
 193         unsigned char e;
 194         const char *original_filename = filename;
 195
 196         if (!filename)
 197                 goto out;
 198         c = *filename;
 199         if (start_type == 1) { /* Must start with '/' */
 200                 if (c != '/')
 201                         goto out;
 202         } else if (start_type == -1) { /* Must not start with '/' */
 203                 if (c == '/')
 204                         goto out;
 205         }
 206         if (c)
 207                 c = *(filename + strlen(filename) - 1);
 208         if (end_type == 1) { /* Must end with '/' */
 209                 if (c != '/')
 210                         goto out;
 211         } else if (end_type == -1) { /* Must not end with '/' */
 212                 if (c == '/')
 213                         goto out;
 214         }
 215         while ((c = *filename++) != '\0') {
 216                 if (c == '\\') {
 217                         switch ((c = *filename++)) {
 218                         case '\\':  /* "\\" */
 219                                 continue;
 220                         case '$':   /* "\$" */
 221                         case '+':   /* "\+" */
 222                         case '?':   /* "\?" */
 223                         case '*':   /* "\*" */
 224                         case '@':   /* "\@" */
 225                         case 'x':   /* "\x" */
 226                         case 'X':   /* "\X" */
 227                         case 'a':   /* "\a" */
 228                         case 'A':   /* "\A" */
 229                         case '-':   /* "\-" */
 230                                 if (pattern_type == -1)
 231                                         break; /* Must not contain pattern */
 232                                 contains_pattern = true;
 233                                 continue;
 234                         case '0':   /* "\ooo" */
 235                         case '1':
 236                         case '2':
 237                         case '3':
 238                                 d = *filename++;
 239                                 if (d < '0' || d > '7')
 240                                         break;
 241                                 e = *filename++;
 242                                 if (e < '0' || e > '7')
 243                                         break;
 244                                 c = tomoyo_make_byte(c, d, e);
 245                                 if (tomoyo_is_invalid(c))
 246                                         continue; /* pattern is not \000 */
 247                         }
 248                         goto out;
 249                 } else if (tomoyo_is_invalid(c)) {
 250                         goto out;
 251                 }
 252         }
 253         if (pattern_type == 1) { /* Must contain pattern */
 254                 if (!contains_pattern)
 255                         goto out;
 256         }
 257         return true;
 258  out:
 259         printk(KERN_DEBUG "%s: Invalid pathname '%s'\n", function,
 260                original_filename);
 261         return false;
 262 }
 263
 264 /**
 265  * tomoyo_is_correct_domain - Check whether the given domainname follows the naming rules.
 266  * @domainname:   The domainname to check.
 267  * @function:     The name of function calling me.
 268  *
 269  * Returns true if @domainname follows the naming rules, false otherwise.
 270  */
 271 bool tomoyo_is_correct_domain(const unsigned char *domainname,
 272                               const char *function)
 273 {
 274         unsigned char c;
 275         unsigned char d;
 276         unsigned char e;
 277         const char *org_domainname = domainname;
 278
 279         if (!domainname || strncmp(domainname, TOMOYO_ROOT_NAME,
 280                                    TOMOYO_ROOT_NAME_LEN))
 281                 goto out;
 282         domainname += TOMOYO_ROOT_NAME_LEN;
 283         if (!*domainname)
 284                 return true;
 285         do {
 286                 if (*domainname++ != ' ')
 287                         goto out;
 288                 if (*domainname++ != '/')
 289                         goto out;
 290                 while ((c = *domainname) != '\0' && c != ' ') {
 291                         domainname++;
 292                         if (c == '\\') {
 293                                 c = *domainname++;
 294                                 switch ((c)) {
 295                                 case '\\':  /* "\\" */
 296                                         continue;
 297                                 case '0':   /* "\ooo" */
 298                                 case '1':
 299                                 case '2':
 300                                 case '3':
 301                                         d = *domainname++;
 302                                         if (d < '0' || d > '7')
 303                                                 break;
 304                                         e = *domainname++;
 305                                         if (e < '0' || e > '7')
 306                                                 break;
 307                                         c = tomoyo_make_byte(c, d, e);
 308                                         if (tomoyo_is_invalid(c))
 309                                                 /* pattern is not \000 */
 310                                                 continue;
 311                                 }
 312                                 goto out;
 313                         } else if (tomoyo_is_invalid(c)) {
 314                                 goto out;
 315                         }
 316                 }
 317         } while (*domainname);
 318         return true;
 319  out:
 320         printk(KERN_DEBUG "%s: Invalid domainname '%s'\n", function,
 321                org_domainname);
 322         return false;
 323 }
 324
 325 /**
 326  * tomoyo_is_domain_def - Check whether the given token can be a domainname.
 327  *
 328  * @buffer: The token to check.
 329  *
 330  * Returns true if @buffer possibly be a domainname, false otherwise.
 331  */
 332 bool tomoyo_is_domain_def(const unsigned char *buffer)
 333 {
 334         return !strncmp(buffer, TOMOYO_ROOT_NAME, TOMOYO_ROOT_NAME_LEN);
 335 }
 336
 337 /**
 338  * tomoyo_find_domain - Find a domain by the given name.
 339  *
 340  * @domainname: The domainname to find.
 341  *
 342  * Caller must call down_read(&tomoyo_domain_list_lock); or
 343  * down_write(&tomoyo_domain_list_lock); .
 344  *
 345  * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
 346  */
 347 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
 348 {
 349         struct tomoyo_domain_info *domain;
 350         struct tomoyo_path_info name;
 351
 352         name.name = domainname;
 353         tomoyo_fill_path_info(&name);
 354         list_for_each_entry(domain, &tomoyo_domain_list, list) {
 355                 if (!domain->is_deleted &&
 356                     !tomoyo_pathcmp(&name, domain->domainname))
 357                         return domain;
 358         }
 359         return NULL;
 360 }
 361
 362 /**
 363  * tomoyo_path_depth - Evaluate the number of '/' in a string.
 364  *
 365  * @pathname: The string to evaluate.
 366  *
 367  * Returns path depth of the string.
 368  *
 369  * I score 2 for each of the '/' in the @pathname
 370  * and score 1 if the @pathname ends with '/'.
 371  */
 372 static int tomoyo_path_depth(const char *pathname)
 373 {
 374         int i = 0;
 375
 376         if (pathname) {
 377                 const char *ep = pathname + strlen(pathname);
 378                 if (pathname < ep--) {
 379                         if (*ep != '/')
 380                                 i++;
 381                         while (pathname <= ep)
 382                                 if (*ep-- == '/')
 383                                         i += 2;
 384                 }
 385         }
 386         return i;
 387 }
 388
 389 /**
 390  * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
 391  *
 392  * @filename: The string to evaluate.
 393  *
 394  * Returns the initial length without a pattern in @filename.
 395  */
 396 static int tomoyo_const_part_length(const char *filename)
 397 {
 398         char c;
 399         int len = 0;
 400
 401         if (!filename)
 402                 return 0;
 403         while ((c = *filename++) != '\0') {
 404                 if (c != '\\') {
 405                         len++;
 406                         continue;
 407                 }
 408                 c = *filename++;
 409                 switch (c) {
 410                 case '\\':  /* "\\" */
 411                         len += 2;
 412                         continue;
 413                 case '0':   /* "\ooo" */
 414                 case '1':
 415                 case '2':
 416                 case '3':
 417                         c = *filename++;
 418                         if (c < '0' || c > '7')
 419                                 break;
 420                         c = *filename++;
 421                         if (c < '0' || c > '7')
 422                                 break;
 423                         len += 4;
 424                         continue;
 425                 }
 426                 break;
 427         }
 428         return len;
 429 }
 430
 431 /**
 432  * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
 433  *
 434  * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
 435  *
 436  * The caller sets "struct tomoyo_path_info"->name.
 437  */
 438 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
 439 {
 440         const char *name = ptr->name;
 441         const int len = strlen(name);
 442
 443         ptr->const_len = tomoyo_const_part_length(name);
 444         ptr->is_dir = len && (name[len - 1] == '/');
 445         ptr->is_patterned = (ptr->const_len < len);
 446         ptr->hash = full_name_hash(name, len);
 447         ptr->depth = tomoyo_path_depth(name);
 448 }
 449
 450 /**
 451  * tomoyo_file_matches_to_pattern2 - Pattern matching without '/' character
 452  * and "\-" pattern.
 453  *
 454  * @filename:     The start of string to check.
 455  * @filename_end: The end of string to check.
 456  * @pattern:      The start of pattern to compare.
 457  * @pattern_end:  The end of pattern to compare.
 458  *
 459  * Returns true if @filename matches @pattern, false otherwise.
 460  */
 461 static bool tomoyo_file_matches_to_pattern2(const char *filename,
 462                                             const char *filename_end,
 463                                             const char *pattern,
 464                                             const char *pattern_end)
 465 {
 466         while (filename < filename_end && pattern < pattern_end) {
 467                 char c;
 468                 if (*pattern != '\\') {
 469                         if (*filename++ != *pattern++)
 470                                 return false;
 471                         continue;
 472                 }
 473                 c = *filename;
 474                 pattern++;
 475                 switch (*pattern) {
 476                         int i;
 477                         int j;
 478                 case '?':
 479                         if (c == '/') {
 480                                 return false;
 481                         } else if (c == '\\') {
 482                                 if (filename[1] == '\\')
 483                                         filename++;
 484                                 else if (tomoyo_is_byte_range(filename + 1))
 485                                         filename += 3;
 486                                 else
 487                                         return false;
 488                         }
 489                         break;
 490                 case '\\':
 491                         if (c != '\\')
 492                                 return false;
 493                         if (*++filename != '\\')
 494                                 return false;
 495                         break;
 496                 case '+':
 497                         if (!isdigit(c))
 498                                 return false;
 499                         break;
 500                 case 'x':
 501                         if (!isxdigit(c))
 502                                 return false;
 503                         break;
 504                 case 'a':
 505                         if (!tomoyo_is_alphabet_char(c))
 506                                 return false;
 507                         break;
 508                 case '0':
 509                 case '1':
 510                 case '2':
 511                 case '3':
 512                         if (c == '\\' && tomoyo_is_byte_range(filename + 1)
 513                             && strncmp(filename + 1, pattern, 3) == 0) {
 514                                 filename += 3;
 515                                 pattern += 2;
 516                                 break;
 517                         }
 518                         return false; /* Not matched. */
 519                 case '*':
 520                 case '@':
 521                         for (i = 0; i <= filename_end - filename; i++) {
 522                                 if (tomoyo_file_matches_to_pattern2(
 523                                                     filename + i, filename_end,
 524                                                     pattern + 1, pattern_end))
 525                                         return true;
 526                                 c = filename[i];
 527                                 if (c == '.' && *pattern == '@')
 528                                         break;
 529                                 if (c != '\\')
 530                                         continue;
 531                                 if (filename[i + 1] == '\\')
 532                                         i++;
 533                                 else if (tomoyo_is_byte_range(filename + i + 1))
 534                                         i += 3;
 535                                 else
 536                                         break; /* Bad pattern. */
 537                         }
 538                         return false; /* Not matched. */
 539                 default:
 540                         j = 0;
 541                         c = *pattern;
 542                         if (c == '$') {
 543                                 while (isdigit(filename[j]))
 544                                         j++;
 545                         } else if (c == 'X') {
 546                                 while (isxdigit(filename[j]))
 547                                         j++;
 548                         } else if (c == 'A') {
 549                                 while (tomoyo_is_alphabet_char(filename[j]))
 550                                         j++;
 551                         }
 552                         for (i = 1; i <= j; i++) {
 553                                 if (tomoyo_file_matches_to_pattern2(
 554                                                     filename + i, filename_end,
 555                                                     pattern + 1, pattern_end))
 556                                         return true;
 557                         }
 558                         return false; /* Not matched or bad pattern. */
 559                 }
 560                 filename++;
 561                 pattern++;
 562         }
 563         while (*pattern == '\\' &&
 564                (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
 565                 pattern += 2;
 566         return filename == filename_end && pattern == pattern_end;
 567 }
 568
 569 /**
 570  * tomoyo_file_matches_to_pattern - Pattern matching without without '/' character.
 571  *
 572  * @filename:     The start of string to check.
 573  * @filename_end: The end of string to check.
 574  * @pattern:      The start of pattern to compare.
 575  * @pattern_end:  The end of pattern to compare.
 576  *
 577  * Returns true if @filename matches @pattern, false otherwise.
 578  */
 579 static bool tomoyo_file_matches_to_pattern(const char *filename,
 580                                            const char *filename_end,
 581                                            const char *pattern,
 582                                            const char *pattern_end)
 583 {
 584         const char *pattern_start = pattern;
 585         bool first = true;
 586         bool result;
 587
 588         while (pattern < pattern_end - 1) {
 589                 /* Split at "\-" pattern. */
 590                 if (*pattern++ != '\\' || *pattern++ != '-')
 591                         continue;
 592                 result = tomoyo_file_matches_to_pattern2(filename,
 593                                                          filename_end,
 594                                                          pattern_start,
 595                                                          pattern - 2);
 596                 if (first)
 597                         result = !result;
 598                 if (result)
 599                         return false;
 600                 first = false;
 601                 pattern_start = pattern;
 602         }
 603         result = tomoyo_file_matches_to_pattern2(filename, filename_end,
 604                                                  pattern_start, pattern_end);
 605         return first ? result : !result;
 606 }
 607
 608 /**
 609  * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
 610  * @filename: The filename to check.
 611  * @pattern:  The pattern to compare.
 612  *
 613  * Returns true if matches, false otherwise.
 614  *
 615  * The following patterns are available.
 616  *   \\     \ itself.
 617  *   \ooo   Octal representation of a byte.
 618  *   \*     More than or equals to 0 character other than '/'.
 619  *   \@     More than or equals to 0 character other than '/' or '.'.
 620  *   \?     1 byte character other than '/'.
 621  *   \$     More than or equals to 1 decimal digit.
 622  *   \+     1 decimal digit.
 623  *   \X     More than or equals to 1 hexadecimal digit.
 624  *   \x     1 hexadecimal digit.
 625  *   \A     More than or equals to 1 alphabet character.
 626  *   \a     1 alphabet character.
 627  *   \-     Subtraction operator.
 628  */
 629 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 630                                  const struct tomoyo_path_info *pattern)
 631 {
 632         /*
 633           if (!filename || !pattern)
 634           return false;
 635         */
 636         const char *f = filename->name;
 637         const char *p = pattern->name;
 638         const int len = pattern->const_len;
 639
 640         /* If @pattern doesn't contain pattern, I can use strcmp(). */
 641         if (!pattern->is_patterned)
 642                 return !tomoyo_pathcmp(filename, pattern);
 643         /* Dont compare if the number of '/' differs. */
 644         if (filename->depth != pattern->depth)
 645                 return false;
 646         /* Compare the initial length without patterns. */
 647         if (strncmp(f, p, len))
 648                 return false;
 649         f += len;
 650         p += len;
 651         /* Main loop. Compare each directory component. */
 652         while (*f && *p) {
 653                 const char *f_delimiter = strchr(f, '/');
 654                 const char *p_delimiter = strchr(p, '/');
 655                 if (!f_delimiter)
 656                         f_delimiter = f + strlen(f);
 657                 if (!p_delimiter)
 658                         p_delimiter = p + strlen(p);
 659                 if (!tomoyo_file_matches_to_pattern(f, f_delimiter,
 660                                                     p, p_delimiter))
 661                         return false;
 662                 f = f_delimiter;
 663                 if (*f)
 664                         f++;
 665                 p = p_delimiter;
 666                 if (*p)
 667                         p++;
 668         }
 669         /* Ignore trailing "\*" and "\@" in @pattern. */
 670         while (*p == '\\' &&
 671                (*(p + 1) == '*' || *(p + 1) == '@'))
 672                 p += 2;
 673         return !*f && !*p;
 674 }
 675
 676 /**
 677  * tomoyo_io_printf - Transactional printf() to "struct tomoyo_io_buffer" structure.
 678  *
 679  * @head: Pointer to "struct tomoyo_io_buffer".
 680  * @fmt:  The printf()'s format string, followed by parameters.
 681  *
 682  * Returns true if output was written, false otherwise.
 683  *
 684  * The snprintf() will truncate, but tomoyo_io_printf() won't.
 685  */
 686 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 687 {
 688         va_list args;
 689         int len;
 690         int pos = head->read_avail;
 691         int size = head->readbuf_size - pos;
 692
 693         if (size <= 0)
 694                 return false;
 695         va_start(args, fmt);
 696         len = vsnprintf(head->read_buf + pos, size, fmt, args);
 697         va_end(args);
 698         if (pos + len >= head->readbuf_size)
 699                 return false;
 700         head->read_avail += len;
 701         return true;
 702 }
 703
 704 /**
 705  * tomoyo_get_exe - Get tomoyo_realpath() of current process.
 706  *
 707  * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
 708  *
 709  * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
 710  * if this function didn't return NULL.
 711  */
 712 static const char *tomoyo_get_exe(void)
 713 {
 714         struct mm_struct *mm = current->mm;
 715         struct vm_area_struct *vma;
 716         const char *cp = NULL;
 717
 718         if (!mm)
 719                 return NULL;
 720         down_read(&mm->mmap_sem);
 721         for (vma = mm->mmap; vma; vma = vma->vm_next) {
 722                 if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) {
 723                         cp = tomoyo_realpath_from_path(&vma->vm_file->f_path);
 724                         break;
 725                 }
 726         }
 727         up_read(&mm->mmap_sem);
 728         return cp;
 729 }
 730
 731 /**
 732  * tomoyo_get_msg - Get warning message.
 733  *
 734  * @is_enforce: Is it enforcing mode?
 735  *
 736  * Returns "ERROR" or "WARNING".
 737  */
 738 const char *tomoyo_get_msg(const bool is_enforce)
 739 {
 740         if (is_enforce)
 741                 return "ERROR";
 742         else
 743                 return "WARNING";
 744 }
 745
 746 /**
 747  * tomoyo_check_flags - Check mode for specified functionality.
 748  *
 749  * @domain: Pointer to "struct tomoyo_domain_info".
 750  * @index:  The functionality to check mode.
 751  *
 752  * TOMOYO checks only process context.
 753  * This code disables TOMOYO's enforcement in case the function is called from
 754  * interrupt context.
 755  */
 756 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 757                                 const u8 index)
 758 {
 759         const u8 profile = domain->profile;
 760
 761         if (WARN_ON(in_interrupt()))
 762                 return 0;
 763         return tomoyo_policy_loaded && index < TOMOYO_MAX_CONTROL_INDEX
 764 #if TOMOYO_MAX_PROFILES != 256
 765                 && profile < TOMOYO_MAX_PROFILES
 766 #endif
 767                 && tomoyo_profile_ptr[profile] ?
 768                 tomoyo_profile_ptr[profile]->value[index] : 0;
 769 }
 770
 771 /**
 772  * tomoyo_verbose_mode - Check whether TOMOYO is verbose mode.
 773  *
 774  * @domain: Pointer to "struct tomoyo_domain_info".
 775  *
 776  * Returns true if domain policy violation warning should be printed to
 777  * console.
 778  */
 779 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain)
 780 {
 781         return tomoyo_check_flags(domain, TOMOYO_VERBOSE) != 0;
 782 }
 783
 784 /**
 785  * tomoyo_domain_quota_is_ok - Check for domain's quota.
 786  *
 787  * @domain: Pointer to "struct tomoyo_domain_info".
 788  *
 789  * Returns true if the domain is not exceeded quota, false otherwise.
 790  */
 791 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain)
 792 {
 793         unsigned int count = 0;
 794         struct tomoyo_acl_info *ptr;
 795
 796         if (!domain)
 797                 return true;
 798         down_read(&tomoyo_domain_acl_info_list_lock);
 799         list_for_each_entry(ptr, &domain->acl_info_list, list) {
 800                 if (ptr->type & TOMOYO_ACL_DELETED)
 801                         continue;
 802                 switch (tomoyo_acl_type2(ptr)) {
 803                         struct tomoyo_single_path_acl_record *acl1;
 804                         struct tomoyo_double_path_acl_record *acl2;
 805                         u16 perm;
 806                 case TOMOYO_TYPE_SINGLE_PATH_ACL:
 807                         acl1 = container_of(ptr,
 808                                     struct tomoyo_single_path_acl_record,
 809                                             head);
 810                         perm = acl1->perm;
 811                         if (perm & (1 << TOMOYO_TYPE_EXECUTE_ACL))
 812                                 count++;
 813                         if (perm &
 814                             ((1 << TOMOYO_TYPE_READ_ACL) |
 815                              (1 << TOMOYO_TYPE_WRITE_ACL)))
 816                                 count++;
 817                         if (perm & (1 << TOMOYO_TYPE_CREATE_ACL))
 818                                 count++;
 819                         if (perm & (1 << TOMOYO_TYPE_UNLINK_ACL))
 820                                 count++;
 821                         if (perm & (1 << TOMOYO_TYPE_MKDIR_ACL))
 822                                 count++;
 823                         if (perm & (1 << TOMOYO_TYPE_RMDIR_ACL))
 824                                 count++;
 825                         if (perm & (1 << TOMOYO_TYPE_MKFIFO_ACL))
 826                                 count++;
 827                         if (perm & (1 << TOMOYO_TYPE_MKSOCK_ACL))
 828                                 count++;
 829                         if (perm & (1 << TOMOYO_TYPE_MKBLOCK_ACL))
 830                                 count++;
 831                         if (perm & (1 << TOMOYO_TYPE_MKCHAR_ACL))
 832                                 count++;
 833                         if (perm & (1 << TOMOYO_TYPE_TRUNCATE_ACL))
 834                                 count++;
 835                         if (perm & (1 << TOMOYO_TYPE_SYMLINK_ACL))
 836                                 count++;
 837                         if (perm & (1 << TOMOYO_TYPE_REWRITE_ACL))
 838                                 count++;
 839                         break;
 840                 case TOMOYO_TYPE_DOUBLE_PATH_ACL:
 841                         acl2 = container_of(ptr,
 842                                     struct tomoyo_double_path_acl_record,
 843                                             head);
 844                         perm = acl2->perm;
 845                         if (perm & (1 << TOMOYO_TYPE_LINK_ACL))
 846                                 count++;
 847                         if (perm & (1 << TOMOYO_TYPE_RENAME_ACL))
 848                                 count++;
 849                         break;
 850                 }
 851         }
 852         up_read(&tomoyo_domain_acl_info_list_lock);
 853         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
 854                 return true;
 855         if (!domain->quota_warned) {
 856                 domain->quota_warned = true;
 857                 printk(KERN_WARNING "TOMOYO-WARNING: "
 858                        "Domain '%s' has so many ACLs to hold. "
 859                        "Stopped learning mode.\n", domain->domainname->name);
 860         }
 861         return false;
 862 }
 863
 864 /**
 865  * tomoyo_find_or_assign_new_profile - Create a new profile.
 866  *
 867  * @profile: Profile number to create.
 868  *
 869  * Returns pointer to "struct tomoyo_profile" on success, NULL otherwise.
 870  */
 871 static struct tomoyo_profile *tomoyo_find_or_assign_new_profile(const unsigned
 872                                                                 int profile)
 873 {
 874         static DEFINE_MUTEX(lock);
 875         struct tomoyo_profile *ptr = NULL;
 876         int i;
 877
 878         if (profile >= TOMOYO_MAX_PROFILES)
 879                 return NULL;
 880         mutex_lock(&lock);
 881         ptr = tomoyo_profile_ptr[profile];
 882         if (ptr)
 883                 goto ok;
 884         ptr = tomoyo_alloc_element(sizeof(*ptr));
 885         if (!ptr)
 886                 goto ok;
 887         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++)
 888                 ptr->value[i] = tomoyo_control_array[i].current_value;
 889         mb(); /* Avoid out-of-order execution. */
 890         tomoyo_profile_ptr[profile] = ptr;
 891  ok:
 892         mutex_unlock(&lock);
 893         return ptr;
 894 }
 895
 896 /**
 897  * tomoyo_write_profile - Write to profile table.
 898  *
 899  * @head: Pointer to "struct tomoyo_io_buffer".
 900  *
 901  * Returns 0 on success, negative value otherwise.
 902  */
 903 static int tomoyo_write_profile(struct tomoyo_io_buffer *head)
 904 {
 905         char *data = head->write_buf;
 906         unsigned int i;
 907         unsigned int value;
 908         char *cp;
 909         struct tomoyo_profile *profile;
 910         unsigned long num;
 911
 912         cp = strchr(data, '-');
 913         if (cp)
 914                 *cp = '\0';
 915         if (strict_strtoul(data, 10, &num))
 916                 return -EINVAL;
 917         if (cp)
 918                 data = cp + 1;
 919         profile = tomoyo_find_or_assign_new_profile(num);
 920         if (!profile)
 921                 return -EINVAL;
 922         cp = strchr(data, '=');
 923         if (!cp)
 924                 return -EINVAL;
 925         *cp = '\0';
 926         if (!strcmp(data, "COMMENT")) {
 927                 profile->comment = tomoyo_save_name(cp + 1);
 928                 return 0;
 929         }
 930         for (i = 0; i < TOMOYO_MAX_CONTROL_INDEX; i++) {
 931                 if (strcmp(data, tomoyo_control_array[i].keyword))
 932                         continue;
 933                 if (sscanf(cp + 1, "%u", &value) != 1) {
 934                         int j;
 935                         const char **modes;
 936                         switch (i) {
 937                         case TOMOYO_VERBOSE:
 938                                 modes = tomoyo_mode_2;
 939                                 break;
 940                         default:
 941                                 modes = tomoyo_mode_4;
 942                                 break;
 943                         }
 944                         for (j = 0; j < 4; j++) {
 945                                 if (strcmp(cp + 1, modes[j]))
 946                                         continue;
 947                                 value = j;
 948                                 break;
 949                         }
 950                         if (j == 4)
 951                                 return -EINVAL;
 952                 } else if (value > tomoyo_control_array[i].max_value) {
 953                         value = tomoyo_control_array[i].max_value;
 954                 }
 955                 profile->value[i] = value;
 956                 return 0;
 957         }
 958         return -EINVAL;
 959 }
 960
 961 /**
 962  * tomoyo_read_profile - Read from profile table.
 963  *
 964  * @head: Pointer to "struct tomoyo_io_buffer".
 965  *
 966  * Returns 0.
 967  */
 968 static int tomoyo_read_profile(struct tomoyo_io_buffer *head)
 969 {
 970         static const int total = TOMOYO_MAX_CONTROL_INDEX + 1;
 971         int step;
 972
 973         if (head->read_eof)
 974                 return 0;
 975         for (step = head->read_step; step < TOMOYO_MAX_PROFILES * total;
 976              step++) {
 977                 const u8 index = step / total;
 978                 u8 type = step % total;
 979                 const struct tomoyo_profile *profile
 980                         = tomoyo_profile_ptr[index];
 981                 head->read_step = step;
 982                 if (!profile)
 983                         continue;
 984                 if (!type) { /* Print profile' comment tag. */
 985                         if (!tomoyo_io_printf(head, "%u-COMMENT=%s\n",
 986                                               index, profile->comment ?
 987                                               profile->comment->name : ""))
 988                                 break;
 989                         continue;
 990                 }
 991                 type--;
 992                 if (type < TOMOYO_MAX_CONTROL_INDEX) {
 993                         const unsigned int value = profile->value[type];
 994                         const char **modes = NULL;
 995                         const char *keyword
 996                                 = tomoyo_control_array[type].keyword;
 997                         switch (tomoyo_control_array[type].max_value) {
 998                         case 3:
 999                                 modes = tomoyo_mode_4;
1000                                 break;
1001                         case 1:
1002                                 modes = tomoyo_mode_2;
1003                                 break;
1004                         }
1005                         if (modes) {
1006                                 if (!tomoyo_io_printf(head, "%u-%s=%s\n", index,
1007                                                       keyword, modes[value]))
1008                                         break;
1009                         } else {
1010                                 if (!tomoyo_io_printf(head, "%u-%s=%u\n", index,
1011                                                       keyword, value))
1012                                         break;
1013                         }
1014                 }
1015         }
1016         if (step == TOMOYO_MAX_PROFILES * total)
1017                 head->read_eof = true;
1018         return 0;
1019 }
1020
1021 /*
1022  * tomoyo_policy_manager_entry is a structure which is used for holding list of
1023  * domainnames or programs which are permitted to modify configuration via
1024  * /sys/kernel/security/tomoyo/ interface.
1025  * It has following fields.
1026  *
1027  *  (1) "list" which is linked to tomoyo_policy_manager_list .
1028  *  (2) "manager" is a domainname or a program's pathname.
1029  *  (3) "is_domain" is a bool which is true if "manager" is a domainname, false
1030  *      otherwise.
1031  *  (4) "is_deleted" is a bool which is true if marked as deleted, false
1032  *      otherwise.
1033  */
1034 struct tomoyo_policy_manager_entry {
1035         struct list_head list;
1036         /* A path to program or a domainname. */
1037         const struct tomoyo_path_info *manager;
1038         bool is_domain;  /* True if manager is a domainname. */
1039         bool is_deleted; /* True if this entry is deleted. */
1040 };
1041
1042 /*
1043  * tomoyo_policy_manager_list is used for holding list of domainnames or
1044  * programs which are permitted to modify configuration via
1045  * /sys/kernel/security/tomoyo/ interface.
1046  *
1047  * An entry is added by
1048  *
1049  * # echo '<kernel> /sbin/mingetty /bin/login /bin/bash' > \
1050  *                                        /sys/kernel/security/tomoyo/manager
1051  *  (if you want to specify by a domainname)
1052  *
1053  *  or
1054  *
1055  * # echo '/usr/lib/ccs/editpolicy' > /sys/kernel/security/tomoyo/manager
1056  *  (if you want to specify by a program's location)
1057  *
1058  * and is deleted by
1059  *
1060  * # echo 'delete <kernel> /sbin/mingetty /bin/login /bin/bash' > \
1061  *                                        /sys/kernel/security/tomoyo/manager
1062  *
1063  *  or
1064  *
1065  * # echo 'delete /usr/lib/ccs/editpolicy' > \
1066  *                                        /sys/kernel/security/tomoyo/manager
1067  *
1068  * and all entries are retrieved by
1069  *
1070  * # cat /sys/kernel/security/tomoyo/manager
1071  */
1072 static LIST_HEAD(tomoyo_policy_manager_list);
1073 static DECLARE_RWSEM(tomoyo_policy_manager_list_lock);
1074
1075 /**
1076  * tomoyo_update_manager_entry - Add a manager entry.
1077  *
1078  * @manager:   The path to manager or the domainnamme.
1079  * @is_delete: True if it is a delete request.
1080  *
1081  * Returns 0 on success, negative value otherwise.
1082  */
1083 static int tomoyo_update_manager_entry(const char *manager,
1084                                        const bool is_delete)
1085 {
1086         struct tomoyo_policy_manager_entry *new_entry;
1087         struct tomoyo_policy_manager_entry *ptr;
1088         const struct tomoyo_path_info *saved_manager;
1089         int error = -ENOMEM;
1090         bool is_domain = false;
1091
1092         if (tomoyo_is_domain_def(manager)) {
1093                 if (!tomoyo_is_correct_domain(manager, __func__))
1094                         return -EINVAL;
1095                 is_domain = true;
1096         } else {
1097                 if (!tomoyo_is_correct_path(manager, 1, -1, -1, __func__))
1098                         return -EINVAL;
1099         }
1100         saved_manager = tomoyo_save_name(manager);
1101         if (!saved_manager)
1102                 return -ENOMEM;
1103         down_write(&tomoyo_policy_manager_list_lock);
1104         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1105                 if (ptr->manager != saved_manager)
1106                         continue;
1107                 ptr->is_deleted = is_delete;
1108                 error = 0;
1109                 goto out;
1110         }
1111         if (is_delete) {
1112                 error = -ENOENT;
1113                 goto out;
1114         }
1115         new_entry = tomoyo_alloc_element(sizeof(*new_entry));
1116         if (!new_entry)
1117                 goto out;
1118         new_entry->manager = saved_manager;
1119         new_entry->is_domain = is_domain;
1120         list_add_tail(&new_entry->list, &tomoyo_policy_manager_list);
1121         error = 0;
1122  out:
1123         up_write(&tomoyo_policy_manager_list_lock);
1124         return error;
1125 }
1126
1127 /**
1128  * tomoyo_write_manager_policy - Write manager policy.
1129  *
1130  * @head: Pointer to "struct tomoyo_io_buffer".
1131  *
1132  * Returns 0 on success, negative value otherwise.
1133  */
1134 static int tomoyo_write_manager_policy(struct tomoyo_io_buffer *head)
1135 {
1136         char *data = head->write_buf;
1137         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1138
1139         if (!strcmp(data, "manage_by_non_root")) {
1140                 tomoyo_manage_by_non_root = !is_delete;
1141                 return 0;
1142         }
1143         return tomoyo_update_manager_entry(data, is_delete);
1144 }
1145
1146 /**
1147  * tomoyo_read_manager_policy - Read manager policy.
1148  *
1149  * @head: Pointer to "struct tomoyo_io_buffer".
1150  *
1151  * Returns 0.
1152  */
1153 static int tomoyo_read_manager_policy(struct tomoyo_io_buffer *head)
1154 {
1155         struct list_head *pos;
1156         bool done = true;
1157
1158         if (head->read_eof)
1159                 return 0;
1160         down_read(&tomoyo_policy_manager_list_lock);
1161         list_for_each_cookie(pos, head->read_var2,
1162                              &tomoyo_policy_manager_list) {
1163                 struct tomoyo_policy_manager_entry *ptr;
1164                 ptr = list_entry(pos, struct tomoyo_policy_manager_entry,
1165                                  list);
1166                 if (ptr->is_deleted)
1167                         continue;
1168                 done = tomoyo_io_printf(head, "%s\n", ptr->manager->name);
1169                 if (!done)
1170                         break;
1171         }
1172         up_read(&tomoyo_policy_manager_list_lock);
1173         head->read_eof = done;
1174         return 0;
1175 }
1176
1177 /**
1178  * tomoyo_is_policy_manager - Check whether the current process is a policy manager.
1179  *
1180  * Returns true if the current process is permitted to modify policy
1181  * via /sys/kernel/security/tomoyo/ interface.
1182  */
1183 static bool tomoyo_is_policy_manager(void)
1184 {
1185         struct tomoyo_policy_manager_entry *ptr;
1186         const char *exe;
1187         const struct task_struct *task = current;
1188         const struct tomoyo_path_info *domainname = tomoyo_domain()->domainname;
1189         bool found = false;
1190
1191         if (!tomoyo_policy_loaded)
1192                 return true;
1193         if (!tomoyo_manage_by_non_root && (task->cred->uid || task->cred->euid))
1194                 return false;
1195         down_read(&tomoyo_policy_manager_list_lock);
1196         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1197                 if (!ptr->is_deleted && ptr->is_domain
1198                     && !tomoyo_pathcmp(domainname, ptr->manager)) {
1199                         found = true;
1200                         break;
1201                 }
1202         }
1203         up_read(&tomoyo_policy_manager_list_lock);
1204         if (found)
1205                 return true;
1206         exe = tomoyo_get_exe();
1207         if (!exe)
1208                 return false;
1209         down_read(&tomoyo_policy_manager_list_lock);
1210         list_for_each_entry(ptr, &tomoyo_policy_manager_list, list) {
1211                 if (!ptr->is_deleted && !ptr->is_domain
1212                     && !strcmp(exe, ptr->manager->name)) {
1213                         found = true;
1214                         break;
1215                 }
1216         }
1217         up_read(&tomoyo_policy_manager_list_lock);
1218         if (!found) { /* Reduce error messages. */
1219                 static pid_t last_pid;
1220                 const pid_t pid = current->pid;
1221                 if (last_pid != pid) {
1222                         printk(KERN_WARNING "%s ( %s ) is not permitted to "
1223                                "update policies.\n", domainname->name, exe);
1224                         last_pid = pid;
1225                 }
1226         }
1227         tomoyo_free(exe);
1228         return found;
1229 }
1230
1231 /**
1232  * tomoyo_is_select_one - Parse select command.
1233  *
1234  * @head: Pointer to "struct tomoyo_io_buffer".
1235  * @data: String to parse.
1236  *
1237  * Returns true on success, false otherwise.
1238  */
1239 static bool tomoyo_is_select_one(struct tomoyo_io_buffer *head,
1240                                  const char *data)
1241 {
1242         unsigned int pid;
1243         struct tomoyo_domain_info *domain = NULL;
1244
1245         if (sscanf(data, "pid=%u", &pid) == 1) {
1246                 struct task_struct *p;
1247                 read_lock(&tasklist_lock);
1248                 p = find_task_by_vpid(pid);
1249                 if (p)
1250                         domain = tomoyo_real_domain(p);
1251                 read_unlock(&tasklist_lock);
1252         } else if (!strncmp(data, "domain=", 7)) {
1253                 if (tomoyo_is_domain_def(data + 7)) {
1254                         down_read(&tomoyo_domain_list_lock);
1255                         domain = tomoyo_find_domain(data + 7);
1256                         up_read(&tomoyo_domain_list_lock);
1257                 }
1258         } else
1259                 return false;
1260         head->write_var1 = domain;
1261         /* Accessing read_buf is safe because head->io_sem is held. */
1262         if (!head->read_buf)
1263                 return true; /* Do nothing if open(O_WRONLY). */
1264         head->read_avail = 0;
1265         tomoyo_io_printf(head, "# select %s\n", data);
1266         head->read_single_domain = true;
1267         head->read_eof = !domain;
1268         if (domain) {
1269                 struct tomoyo_domain_info *d;
1270                 head->read_var1 = NULL;
1271                 down_read(&tomoyo_domain_list_lock);
1272                 list_for_each_entry(d, &tomoyo_domain_list, list) {
1273                         if (d == domain)
1274                                 break;
1275                         head->read_var1 = &d->list;
1276                 }
1277                 up_read(&tomoyo_domain_list_lock);
1278                 head->read_var2 = NULL;
1279                 head->read_bit = 0;
1280                 head->read_step = 0;
1281                 if (domain->is_deleted)
1282                         tomoyo_io_printf(head, "# This is a deleted domain.\n");
1283         }
1284         return true;
1285 }
1286
1287 /**
1288  * tomoyo_write_domain_policy - Write domain policy.
1289  *
1290  * @head: Pointer to "struct tomoyo_io_buffer".
1291  *
1292  * Returns 0 on success, negative value otherwise.
1293  */
1294 static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
1295 {
1296         char *data = head->write_buf;
1297         struct tomoyo_domain_info *domain = head->write_var1;
1298         bool is_delete = false;
1299         bool is_select = false;
1300         unsigned int profile;
1301
1302         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE))
1303                 is_delete = true;
1304         else if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_SELECT))
1305                 is_select = true;
1306         if (is_select && tomoyo_is_select_one(head, data))
1307                 return 0;
1308         /* Don't allow updating policies by non manager programs. */
1309         if (!tomoyo_is_policy_manager())
1310                 return -EPERM;
1311         if (tomoyo_is_domain_def(data)) {
1312                 domain = NULL;
1313                 if (is_delete)
1314                         tomoyo_delete_domain(data);
1315                 else if (is_select) {
1316                         down_read(&tomoyo_domain_list_lock);
1317                         domain = tomoyo_find_domain(data);
1318                         up_read(&tomoyo_domain_list_lock);
1319                 } else
1320                         domain = tomoyo_find_or_assign_new_domain(data, 0);
1321                 head->write_var1 = domain;
1322                 return 0;
1323         }
1324         if (!domain)
1325                 return -EINVAL;
1326
1327         if (sscanf(data, TOMOYO_KEYWORD_USE_PROFILE "%u", &profile) == 1
1328             && profile < TOMOYO_MAX_PROFILES) {
1329                 if (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded)
1330                         domain->profile = (u8) profile;
1331                 return 0;
1332         }
1333         if (!strcmp(data, TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ)) {
1334                 tomoyo_set_domain_flag(domain, is_delete,
1335                                TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ);
1336                 return 0;
1337         }
1338         return tomoyo_write_file_policy(data, domain, is_delete);
1339 }
1340
1341 /**
1342  * tomoyo_print_single_path_acl - Print a single path ACL entry.
1343  *
1344  * @head: Pointer to "struct tomoyo_io_buffer".
1345  * @ptr:  Pointer to "struct tomoyo_single_path_acl_record".
1346  *
1347  * Returns true on success, false otherwise.
1348  */
1349 static bool tomoyo_print_single_path_acl(struct tomoyo_io_buffer *head,
1350                                          struct tomoyo_single_path_acl_record *
1351                                          ptr)
1352 {
1353         int pos;
1354         u8 bit;
1355         const char *atmark = "";
1356         const char *filename;
1357         const u16 perm = ptr->perm;
1358
1359         filename = ptr->filename->name;
1360         for (bit = head->read_bit; bit < TOMOYO_MAX_SINGLE_PATH_OPERATION;
1361              bit++) {
1362                 const char *msg;
1363                 if (!(perm & (1 << bit)))
1364                         continue;
1365                 /* Print "read/write" instead of "read" and "write". */
1366                 if ((bit == TOMOYO_TYPE_READ_ACL ||
1367                      bit == TOMOYO_TYPE_WRITE_ACL)
1368                     && (perm & (1 << TOMOYO_TYPE_READ_WRITE_ACL)))
1369                         continue;
1370                 msg = tomoyo_sp2keyword(bit);
1371                 pos = head->read_avail;
1372                 if (!tomoyo_io_printf(head, "allow_%s %s%s\n", msg,
1373                                       atmark, filename))
1374                         goto out;
1375         }
1376         head->read_bit = 0;
1377         return true;
1378  out:
1379         head->read_bit = bit;
1380         head->read_avail = pos;
1381         return false;
1382 }
1383
1384 /**
1385  * tomoyo_print_double_path_acl - Print a double path ACL entry.
1386  *
1387  * @head: Pointer to "struct tomoyo_io_buffer".
1388  * @ptr:  Pointer to "struct tomoyo_double_path_acl_record".
1389  *
1390  * Returns true on success, false otherwise.
1391  */
1392 static bool tomoyo_print_double_path_acl(struct tomoyo_io_buffer *head,
1393                                          struct tomoyo_double_path_acl_record *
1394                                          ptr)
1395 {
1396         int pos;
1397         const char *atmark1 = "";
1398         const char *atmark2 = "";
1399         const char *filename1;
1400         const char *filename2;
1401         const u8 perm = ptr->perm;
1402         u8 bit;
1403
1404         filename1 = ptr->filename1->name;
1405         filename2 = ptr->filename2->name;
1406         for (bit = head->read_bit; bit < TOMOYO_MAX_DOUBLE_PATH_OPERATION;
1407              bit++) {
1408                 const char *msg;
1409                 if (!(perm & (1 << bit)))
1410                         continue;
1411                 msg = tomoyo_dp2keyword(bit);
1412                 pos = head->read_avail;
1413                 if (!tomoyo_io_printf(head, "allow_%s %s%s %s%s\n", msg,
1414                                       atmark1, filename1, atmark2, filename2))
1415                         goto out;
1416         }
1417         head->read_bit = 0;
1418         return true;
1419  out:
1420         head->read_bit = bit;
1421         head->read_avail = pos;
1422         return false;
1423 }
1424
1425 /**
1426  * tomoyo_print_entry - Print an ACL entry.
1427  *
1428  * @head: Pointer to "struct tomoyo_io_buffer".
1429  * @ptr:  Pointer to an ACL entry.
1430  *
1431  * Returns true on success, false otherwise.
1432  */
1433 static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
1434                                struct tomoyo_acl_info *ptr)
1435 {
1436         const u8 acl_type = tomoyo_acl_type2(ptr);
1437
1438         if (acl_type & TOMOYO_ACL_DELETED)
1439                 return true;
1440         if (acl_type == TOMOYO_TYPE_SINGLE_PATH_ACL) {
1441                 struct tomoyo_single_path_acl_record *acl
1442                         = container_of(ptr,
1443                                        struct tomoyo_single_path_acl_record,
1444                                        head);
1445                 return tomoyo_print_single_path_acl(head, acl);
1446         }
1447         if (acl_type == TOMOYO_TYPE_DOUBLE_PATH_ACL) {
1448                 struct tomoyo_double_path_acl_record *acl
1449                         = container_of(ptr,
1450                                        struct tomoyo_double_path_acl_record,
1451                                        head);
1452                 return tomoyo_print_double_path_acl(head, acl);
1453         }
1454         BUG(); /* This must not happen. */
1455         return false;
1456 }
1457
1458 /**
1459  * tomoyo_read_domain_policy - Read domain policy.
1460  *
1461  * @head: Pointer to "struct tomoyo_io_buffer".
1462  *
1463  * Returns 0.
1464  */
1465 static int tomoyo_read_domain_policy(struct tomoyo_io_buffer *head)
1466 {
1467         struct list_head *dpos;
1468         struct list_head *apos;
1469         bool done = true;
1470
1471         if (head->read_eof)
1472                 return 0;
1473         if (head->read_step == 0)
1474                 head->read_step = 1;
1475         down_read(&tomoyo_domain_list_lock);
1476         list_for_each_cookie(dpos, head->read_var1, &tomoyo_domain_list) {
1477                 struct tomoyo_domain_info *domain;
1478                 const char *quota_exceeded = "";
1479                 const char *transition_failed = "";
1480                 const char *ignore_global_allow_read = "";
1481                 domain = list_entry(dpos, struct tomoyo_domain_info, list);
1482                 if (head->read_step != 1)
1483                         goto acl_loop;
1484                 if (domain->is_deleted && !head->read_single_domain)
1485                         continue;
1486                 /* Print domainname and flags. */
1487                 if (domain->quota_warned)
1488                         quota_exceeded = "quota_exceeded\n";
1489                 if (domain->flags & TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED)
1490                         transition_failed = "transition_failed\n";
1491                 if (domain->flags &
1492                     TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ)
1493                         ignore_global_allow_read
1494                                 = TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "\n";
1495                 done = tomoyo_io_printf(head, "%s\n" TOMOYO_KEYWORD_USE_PROFILE
1496                                         "%u\n%s%s%s\n",
1497                                         domain->domainname->name,
1498                                         domain->profile, quota_exceeded,
1499                                         transition_failed,
1500                                         ignore_global_allow_read);
1501                 if (!done)
1502                         break;
1503                 head->read_step = 2;
1504 acl_loop:
1505                 if (head->read_step == 3)
1506                         goto tail_mark;
1507                 /* Print ACL entries in the domain. */
1508                 down_read(&tomoyo_domain_acl_info_list_lock);
1509                 list_for_each_cookie(apos, head->read_var2,
1510                                      &domain->acl_info_list) {
1511                         struct tomoyo_acl_info *ptr
1512                                 = list_entry(apos, struct tomoyo_acl_info,
1513                                              list);
1514                         done = tomoyo_print_entry(head, ptr);
1515                         if (!done)
1516                                 break;
1517                 }
1518                 up_read(&tomoyo_domain_acl_info_list_lock);
1519                 if (!done)
1520                         break;
1521                 head->read_step = 3;
1522 tail_mark:
1523                 done = tomoyo_io_printf(head, "\n");
1524                 if (!done)
1525                         break;
1526                 head->read_step = 1;
1527                 if (head->read_single_domain)
1528                         break;
1529         }
1530         up_read(&tomoyo_domain_list_lock);
1531         head->read_eof = done;
1532         return 0;
1533 }
1534
1535 /**
1536  * tomoyo_write_domain_profile - Assign profile for specified domain.
1537  *
1538  * @head: Pointer to "struct tomoyo_io_buffer".
1539  *
1540  * Returns 0 on success, -EINVAL otherwise.
1541  *
1542  * This is equivalent to doing
1543  *
1544  *     ( echo "select " $domainname; echo "use_profile " $profile ) |
1545  *     /usr/lib/ccs/loadpolicy -d
1546  */
1547 static int tomoyo_write_domain_profile(struct tomoyo_io_buffer *head)
1548 {
1549         char *data = head->write_buf;
1550         char *cp = strchr(data, ' ');
1551         struct tomoyo_domain_info *domain;
1552         unsigned long profile;
1553
1554         if (!cp)
1555                 return -EINVAL;
1556         *cp = '\0';
1557         down_read(&tomoyo_domain_list_lock);
1558         domain = tomoyo_find_domain(cp + 1);
1559         up_read(&tomoyo_domain_list_lock);
1560         if (strict_strtoul(data, 10, &profile))
1561                 return -EINVAL;
1562         if (domain && profile < TOMOYO_MAX_PROFILES
1563             && (tomoyo_profile_ptr[profile] || !tomoyo_policy_loaded))
1564                 domain->profile = (u8) profile;
1565         return 0;
1566 }
1567
1568 /**
1569  * tomoyo_read_domain_profile - Read only domainname and profile.
1570  *
1571  * @head: Pointer to "struct tomoyo_io_buffer".
1572  *
1573  * Returns list of profile number and domainname pairs.
1574  *
1575  * This is equivalent to doing
1576  *
1577  *     grep -A 1 '^<kernel>' /sys/kernel/security/tomoyo/domain_policy |
1578  *     awk ' { if ( domainname == "" ) { if ( $1 == "<kernel>" )
1579  *     domainname = $0; } else if ( $1 == "use_profile" ) {
1580  *     print $2 " " domainname; domainname = ""; } } ; '
1581  */
1582 static int tomoyo_read_domain_profile(struct tomoyo_io_buffer *head)
1583 {
1584         struct list_head *pos;
1585         bool done = true;
1586
1587         if (head->read_eof)
1588                 return 0;
1589         down_read(&tomoyo_domain_list_lock);
1590         list_for_each_cookie(pos, head->read_var1, &tomoyo_domain_list) {
1591                 struct tomoyo_domain_info *domain;
1592                 domain = list_entry(pos, struct tomoyo_domain_info, list);
1593                 if (domain->is_deleted)
1594                         continue;
1595                 done = tomoyo_io_printf(head, "%u %s\n", domain->profile,
1596                                         domain->domainname->name);
1597                 if (!done)
1598                         break;
1599         }
1600         up_read(&tomoyo_domain_list_lock);
1601         head->read_eof = done;
1602         return 0;
1603 }
1604
1605 /**
1606  * tomoyo_write_pid: Specify PID to obtain domainname.
1607  *
1608  * @head: Pointer to "struct tomoyo_io_buffer".
1609  *
1610  * Returns 0.
1611  */
1612 static int tomoyo_write_pid(struct tomoyo_io_buffer *head)
1613 {
1614         unsigned long pid;
1615         /* No error check. */
1616         strict_strtoul(head->write_buf, 10, &pid);
1617         head->read_step = (int) pid;
1618         head->read_eof = false;
1619         return 0;
1620 }
1621
1622 /**
1623  * tomoyo_read_pid - Get domainname of the specified PID.
1624  *
1625  * @head: Pointer to "struct tomoyo_io_buffer".
1626  *
1627  * Returns the domainname which the specified PID is in on success,
1628  * empty string otherwise.
1629  * The PID is specified by tomoyo_write_pid() so that the user can obtain
1630  * using read()/write() interface rather than sysctl() interface.
1631  */
1632 static int tomoyo_read_pid(struct tomoyo_io_buffer *head)
1633 {
1634         if (head->read_avail == 0 && !head->read_eof) {
1635                 const int pid = head->read_step;
1636                 struct task_struct *p;
1637                 struct tomoyo_domain_info *domain = NULL;
1638                 read_lock(&tasklist_lock);
1639                 p = find_task_by_vpid(pid);
1640                 if (p)
1641                         domain = tomoyo_real_domain(p);
1642                 read_unlock(&tasklist_lock);
1643                 if (domain)
1644                         tomoyo_io_printf(head, "%d %u %s", pid, domain->profile,
1645                                          domain->domainname->name);
1646                 head->read_eof = true;
1647         }
1648         return 0;
1649 }
1650
1651 /**
1652  * tomoyo_write_exception_policy - Write exception policy.
1653  *
1654  * @head: Pointer to "struct tomoyo_io_buffer".
1655  *
1656  * Returns 0 on success, negative value otherwise.
1657  */
1658 static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
1659 {
1660         char *data = head->write_buf;
1661         bool is_delete = tomoyo_str_starts(&data, TOMOYO_KEYWORD_DELETE);
1662
1663         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_KEEP_DOMAIN))
1664                 return tomoyo_write_domain_keeper_policy(data, false,
1665                                                          is_delete);
1666         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_KEEP_DOMAIN))
1667                 return tomoyo_write_domain_keeper_policy(data, true, is_delete);
1668         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_INITIALIZE_DOMAIN))
1669                 return tomoyo_write_domain_initializer_policy(data, false,
1670                                                               is_delete);
1671         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
1672                 return tomoyo_write_domain_initializer_policy(data, true,
1673                                                               is_delete);
1674         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
1675                 return tomoyo_write_alias_policy(data, is_delete);
1676         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
1677                 return tomoyo_write_globally_readable_policy(data, is_delete);
1678         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_FILE_PATTERN))
1679                 return tomoyo_write_pattern_policy(data, is_delete);
1680         if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_DENY_REWRITE))
1681                 return tomoyo_write_no_rewrite_policy(data, is_delete);
1682         return -EINVAL;
1683 }
1684
1685 /**
1686  * tomoyo_read_exception_policy - Read exception policy.
1687  *
1688  * @head: Pointer to "struct tomoyo_io_buffer".
1689  *
1690  * Returns 0 on success, -EINVAL otherwise.
1691  */
1692 static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
1693 {
1694         if (!head->read_eof) {
1695                 switch (head->read_step) {
1696                 case 0:
1697                         head->read_var2 = NULL;
1698                         head->read_step = 1;
1699                 case 1:
1700                         if (!tomoyo_read_domain_keeper_policy(head))
1701                                 break;
1702                         head->read_var2 = NULL;
1703                         head->read_step = 2;
1704                 case 2:
1705                         if (!tomoyo_read_globally_readable_policy(head))
1706                                 break;
1707                         head->read_var2 = NULL;
1708                         head->read_step = 3;
1709                 case 3:
1710                         head->read_var2 = NULL;
1711                         head->read_step = 4;
1712                 case 4:
1713                         if (!tomoyo_read_domain_initializer_policy(head))
1714                                 break;
1715                         head->read_var2 = NULL;
1716                         head->read_step = 5;
1717                 case 5:
1718                         if (!tomoyo_read_alias_policy(head))
1719                                 break;
1720                         head->read_var2 = NULL;
1721                         head->read_step = 6;
1722                 case 6:
1723                         head->read_var2 = NULL;
1724                         head->read_step = 7;
1725                 case 7:
1726                         if (!tomoyo_read_file_pattern(head))
1727                                 break;
1728                         head->read_var2 = NULL;
1729                         head->read_step = 8;
1730                 case 8:
1731                         if (!tomoyo_read_no_rewrite_policy(head))
1732                                 break;
1733                         head->read_var2 = NULL;
1734                         head->read_step = 9;
1735                 case 9:
1736                         head->read_eof = true;
1737                         break;
1738                 default:
1739                         return -EINVAL;
1740                 }
1741         }
1742         return 0;
1743 }
1744
1745 /* path to policy loader */
1746 static const char *tomoyo_loader = "/sbin/tomoyo-init";
1747
1748 /**
1749  * tomoyo_policy_loader_exists - Check whether /sbin/tomoyo-init exists.
1750  *
1751  * Returns true if /sbin/tomoyo-init exists, false otherwise.
1752  */
1753 static bool tomoyo_policy_loader_exists(void)
1754 {
1755         /*
1756          * Don't activate MAC if the policy loader doesn't exist.
1757          * If the initrd includes /sbin/init but real-root-dev has not
1758          * mounted on / yet, activating MAC will block the system since
1759          * policies are not loaded yet.
1760          * Thus, let do_execve() call this function everytime.
1761          */
1762         struct path path;
1763
1764         if (kern_path(tomoyo_loader, LOOKUP_FOLLOW, &path)) {
1765                 printk(KERN_INFO "Not activating Mandatory Access Control now "
1766                        "since %s doesn't exist.\n", tomoyo_loader);
1767                 return false;
1768         }
1769         path_put(&path);
1770         return true;
1771 }
1772
1773 /**
1774  * tomoyo_load_policy - Run external policy loader to load policy.
1775  *
1776  * @filename: The program about to start.
1777  *
1778  * This function checks whether @filename is /sbin/init , and if so
1779  * invoke /sbin/tomoyo-init and wait for the termination of /sbin/tomoyo-init
1780  * and then continues invocation of /sbin/init.
1781  * /sbin/tomoyo-init reads policy files in /etc/tomoyo/ directory and
1782  * writes to /sys/kernel/security/tomoyo/ interfaces.
1783  *
1784  * Returns nothing.
1785  */
1786 void tomoyo_load_policy(const char *filename)
1787 {
1788         char *argv[2];
1789         char *envp[3];
1790
1791         if (tomoyo_policy_loaded)
1792                 return;
1793         /*
1794          * Check filename is /sbin/init or /sbin/tomoyo-start.
1795          * /sbin/tomoyo-start is a dummy filename in case where /sbin/init can't
1796          * be passed.
1797          * You can create /sbin/tomoyo-start by
1798          * "ln -s /bin/true /sbin/tomoyo-start".
1799          */
1800         if (strcmp(filename, "/sbin/init") &&
1801             strcmp(filename, "/sbin/tomoyo-start"))
1802                 return;
1803         if (!tomoyo_policy_loader_exists())
1804                 return;
1805
1806         printk(KERN_INFO "Calling %s to load policy. Please wait.\n",
1807                tomoyo_loader);
1808         argv[0] = (char *) tomoyo_loader;
1809         argv[1] = NULL;
1810         envp[0] = "HOME=/";
1811         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
1812         envp[2] = NULL;
1813         call_usermodehelper(argv[0], argv, envp, 1);
1814
1815         printk(KERN_INFO "TOMOYO: 2.2.0   2009/04/01\n");
1816         printk(KERN_INFO "Mandatory Access Control activated.\n");
1817         tomoyo_policy_loaded = true;
1818         { /* Check all profiles currently assigned to domains are defined. */
1819                 struct tomoyo_domain_info *domain;
1820                 down_read(&tomoyo_domain_list_lock);
1821                 list_for_each_entry(domain, &tomoyo_domain_list, list) {
1822                         const u8 profile = domain->profile;
1823                         if (tomoyo_profile_ptr[profile])
1824                                 continue;
1825                         panic("Profile %u (used by '%s') not defined.\n",
1826                               profile, domain->domainname->name);
1827                 }
1828                 up_read(&tomoyo_domain_list_lock);
1829         }
1830 }
1831
1832 /**
1833  * tomoyo_read_version: Get version.
1834  *
1835  * @head: Pointer to "struct tomoyo_io_buffer".
1836  *
1837  * Returns version information.
1838  */
1839 static int tomoyo_read_version(struct tomoyo_io_buffer *head)
1840 {
1841         if (!head->read_eof) {
1842                 tomoyo_io_printf(head, "2.2.0");
1843                 head->read_eof = true;
1844         }
1845         return 0;
1846 }
1847
1848 /**
1849  * tomoyo_read_self_domain - Get the current process's domainname.
1850  *
1851  * @head: Pointer to "struct tomoyo_io_buffer".
1852  *
1853  * Returns the current process's domainname.
1854  */
1855 static int tomoyo_read_self_domain(struct tomoyo_io_buffer *head)
1856 {
1857         if (!head->read_eof) {
1858                 /*
1859                  * tomoyo_domain()->domainname != NULL
1860                  * because every process belongs to a domain and
1861                  * the domain's name cannot be NULL.
1862                  */
1863                 tomoyo_io_printf(head, "%s", tomoyo_domain()->domainname->name);
1864                 head->read_eof = true;
1865         }
1866         return 0;
1867 }
1868
1869 /**
1870  * tomoyo_open_control - open() for /sys/kernel/security/tomoyo/ interface.
1871  *
1872  * @type: Type of interface.
1873  * @file: Pointer to "struct file".
1874  *
1875  * Associates policy handler and returns 0 on success, -ENOMEM otherwise.
1876  */
1877 static int tomoyo_open_control(const u8 type, struct file *file)
1878 {
1879         struct tomoyo_io_buffer *head = tomoyo_alloc(sizeof(*head));
1880
1881         if (!head)
1882                 return -ENOMEM;
1883         mutex_init(&head->io_sem);
1884         switch (type) {
1885         case TOMOYO_DOMAINPOLICY:
1886                 /* /sys/kernel/security/tomoyo/domain_policy */
1887                 head->write = tomoyo_write_domain_policy;
1888                 head->read = tomoyo_read_domain_policy;
1889                 break;
1890         case TOMOYO_EXCEPTIONPOLICY:
1891                 /* /sys/kernel/security/tomoyo/exception_policy */
1892                 head->write = tomoyo_write_exception_policy;
1893                 head->read = tomoyo_read_exception_policy;
1894                 break;
1895         case TOMOYO_SELFDOMAIN:
1896                 /* /sys/kernel/security/tomoyo/self_domain */
1897                 head->read = tomoyo_read_self_domain;
1898                 break;
1899         case TOMOYO_DOMAIN_STATUS:
1900                 /* /sys/kernel/security/tomoyo/.domain_status */
1901                 head->write = tomoyo_write_domain_profile;
1902                 head->read = tomoyo_read_domain_profile;
1903                 break;
1904         case TOMOYO_PROCESS_STATUS:
1905                 /* /sys/kernel/security/tomoyo/.process_status */
1906                 head->write = tomoyo_write_pid;
1907                 head->read = tomoyo_read_pid;
1908                 break;
1909         case TOMOYO_VERSION:
1910                 /* /sys/kernel/security/tomoyo/version */
1911                 head->read = tomoyo_read_version;
1912                 head->readbuf_size = 128;
1913                 break;
1914         case TOMOYO_MEMINFO:
1915                 /* /sys/kernel/security/tomoyo/meminfo */
1916                 head->write = tomoyo_write_memory_quota;
1917                 head->read = tomoyo_read_memory_counter;
1918                 head->readbuf_size = 512;
1919                 break;
1920         case TOMOYO_PROFILE:
1921                 /* /sys/kernel/security/tomoyo/profile */
1922                 head->write = tomoyo_write_profile;
1923                 head->read = tomoyo_read_profile;
1924                 break;
1925         case TOMOYO_MANAGER:
1926                 /* /sys/kernel/security/tomoyo/manager */
1927                 head->write = tomoyo_write_manager_policy;
1928                 head->read = tomoyo_read_manager_policy;
1929                 break;
1930         }
1931         if (!(file->f_mode & FMODE_READ)) {
1932                 /*
1933                  * No need to allocate read_buf since it is not opened
1934                  * for reading.
1935                  */
1936                 head->read = NULL;
1937         } else {
1938                 if (!head->readbuf_size)
1939                         head->readbuf_size = 4096 * 2;
1940                 head->read_buf = tomoyo_alloc(head->readbuf_size);
1941                 if (!head->read_buf) {
1942                         tomoyo_free(head);
1943                         return -ENOMEM;
1944                 }
1945         }
1946         if (!(file->f_mode & FMODE_WRITE)) {
1947                 /*
1948                  * No need to allocate write_buf since it is not opened
1949                  * for writing.
1950                  */
1951                 head->write = NULL;
1952         } else if (head->write) {
1953                 head->writebuf_size = 4096 * 2;
1954                 head->write_buf = tomoyo_alloc(head->writebuf_size);
1955                 if (!head->write_buf) {
1956                         tomoyo_free(head->read_buf);
1957                         tomoyo_free(head);
1958                         return -ENOMEM;
1959                 }
1960         }
1961         file->private_data = head;
1962         /*
1963          * Call the handler now if the file is
1964          * /sys/kernel/security/tomoyo/self_domain
1965          * so that the user can use
1966          * cat < /sys/kernel/security/tomoyo/self_domain"
1967          * to know the current process's domainname.
1968          */
1969         if (type == TOMOYO_SELFDOMAIN)
1970                 tomoyo_read_control(file, NULL, 0);
1971         return 0;
1972 }
1973
1974 /**
1975  * tomoyo_read_control - read() for /sys/kernel/security/tomoyo/ interface.
1976  *
1977  * @file:       Pointer to "struct file".
1978  * @buffer:     Poiner to buffer to write to.
1979  * @buffer_len: Size of @buffer.
1980  *
1981  * Returns bytes read on success, negative value otherwise.
1982  */
1983 static int tomoyo_read_control(struct file *file, char __user *buffer,
1984                                const int buffer_len)
1985 {
1986         int len = 0;
1987         struct tomoyo_io_buffer *head = file->private_data;
1988         char *cp;
1989
1990         if (!head->read)
1991                 return -ENOSYS;
1992         if (mutex_lock_interruptible(&head->io_sem))
1993                 return -EINTR;
1994         /* Call the policy handler. */
1995         len = head->read(head);
1996         if (len < 0)
1997                 goto out;
1998         /* Write to buffer. */
1999         len = head->read_avail;
2000         if (len > buffer_len)
2001                 len = buffer_len;
2002         if (!len)
2003                 goto out;
2004         /* head->read_buf changes by some functions. */
2005         cp = head->read_buf;
2006         if (copy_to_user(buffer, cp, len)) {
2007                 len = -EFAULT;
2008                 goto out;
2009         }
2010         head->read_avail -= len;
2011         memmove(cp, cp + len, head->read_avail);
2012  out:
2013         mutex_unlock(&head->io_sem);
2014         return len;
2015 }
2016
2017 /**
2018  * tomoyo_write_control - write() for /sys/kernel/security/tomoyo/ interface.
2019  *
2020  * @file:       Pointer to "struct file".
2021  * @buffer:     Pointer to buffer to read from.
2022  * @buffer_len: Size of @buffer.
2023  *
2024  * Returns @buffer_len on success, negative value otherwise.
2025  */
2026 static int tomoyo_write_control(struct file *file, const char __user *buffer,
2027                                 const int buffer_len)
2028 {
2029         struct tomoyo_io_buffer *head = file->private_data;
2030         int error = buffer_len;
2031         int avail_len = buffer_len;
2032         char *cp0 = head->write_buf;
2033
2034         if (!head->write)
2035                 return -ENOSYS;
2036         if (!access_ok(VERIFY_READ, buffer, buffer_len))
2037                 return -EFAULT;
2038         /* Don't allow updating policies by non manager programs. */
2039         if (head->write != tomoyo_write_pid &&
2040             head->write != tomoyo_write_domain_policy &&
2041             !tomoyo_is_policy_manager())
2042                 return -EPERM;
2043         if (mutex_lock_interruptible(&head->io_sem))
2044                 return -EINTR;
2045         /* Read a line and dispatch it to the policy handler. */
2046         while (avail_len > 0) {
2047                 char c;
2048                 if (head->write_avail >= head->writebuf_size - 1) {
2049                         error = -ENOMEM;
2050                         break;
2051                 } else if (get_user(c, buffer)) {
2052                         error = -EFAULT;
2053                         break;
2054                 }
2055                 buffer++;
2056                 avail_len--;
2057                 cp0[head->write_avail++] = c;
2058                 if (c != '\n')
2059                         continue;
2060                 cp0[head->write_avail - 1] = '\0';
2061                 head->write_avail = 0;
2062                 tomoyo_normalize_line(cp0);
2063                 head->write(head);
2064         }
2065         mutex_unlock(&head->io_sem);
2066         return error;
2067 }
2068
2069 /**
2070  * tomoyo_close_control - close() for /sys/kernel/security/tomoyo/ interface.
2071  *
2072  * @file: Pointer to "struct file".
2073  *
2074  * Releases memory and returns 0.
2075  */
2076 static int tomoyo_close_control(struct file *file)
2077 {
2078         struct tomoyo_io_buffer *head = file->private_data;
2079
2080         /* Release memory used for policy I/O. */
2081         tomoyo_free(head->read_buf);
2082         head->read_buf = NULL;
2083         tomoyo_free(head->write_buf);
2084         head->write_buf = NULL;
2085         tomoyo_free(head);
2086         head = NULL;
2087         file->private_data = NULL;
2088         return 0;
2089 }
2090
2091 /**
2092  * tomoyo_alloc_acl_element - Allocate permanent memory for ACL entry.
2093  *
2094  * @acl_type:  Type of ACL entry.
2095  *
2096  * Returns pointer to the ACL entry on success, NULL otherwise.
2097  */
2098 void *tomoyo_alloc_acl_element(const u8 acl_type)
2099 {
2100         int len;
2101         struct tomoyo_acl_info *ptr;
2102
2103         switch (acl_type) {
2104         case TOMOYO_TYPE_SINGLE_PATH_ACL:
2105                 len = sizeof(struct tomoyo_single_path_acl_record);
2106                 break;
2107         case TOMOYO_TYPE_DOUBLE_PATH_ACL:
2108                 len = sizeof(struct tomoyo_double_path_acl_record);
2109                 break;
2110         default:
2111                 return NULL;
2112         }
2113         ptr = tomoyo_alloc_element(len);
2114         if (!ptr)
2115                 return NULL;
2116         ptr->type = acl_type;
2117         return ptr;
2118 }
2119
2120 /**
2121  * tomoyo_open - open() for /sys/kernel/security/tomoyo/ interface.
2122  *
2123  * @inode: Pointer to "struct inode".
2124  * @file:  Pointer to "struct file".
2125  *
2126  * Returns 0 on success, negative value otherwise.
2127  */
2128 static int tomoyo_open(struct inode *inode, struct file *file)
2129 {
2130         const int key = ((u8 *) file->f_path.dentry->d_inode->i_private)
2131                 - ((u8 *) NULL);
2132         return tomoyo_open_control(key, file);
2133 }
2134
2135 /**
2136  * tomoyo_release - close() for /sys/kernel/security/tomoyo/ interface.
2137  *
2138  * @inode: Pointer to "struct inode".
2139  * @file:  Pointer to "struct file".
2140  *
2141  * Returns 0 on success, negative value otherwise.
2142  */
2143 static int tomoyo_release(struct inode *inode, struct file *file)
2144 {
2145         return tomoyo_close_control(file);
2146 }
2147
2148 /**
2149  * tomoyo_read - read() for /sys/kernel/security/tomoyo/ interface.
2150  *
2151  * @file:  Pointer to "struct file".
2152  * @buf:   Pointer to buffer.
2153  * @count: Size of @buf.
2154  * @ppos:  Unused.
2155  *
2156  * Returns bytes read on success, negative value otherwise.
2157  */
2158 static ssize_t tomoyo_read(struct file *file, char __user *buf, size_t count,
2159                            loff_t *ppos)
2160 {
2161         return tomoyo_read_control(file, buf, count);
2162 }
2163
2164 /**
2165  * tomoyo_write - write() for /sys/kernel/security/tomoyo/ interface.
2166  *
2167  * @file:  Pointer to "struct file".
2168  * @buf:   Pointer to buffer.
2169  * @count: Size of @buf.
2170  * @ppos:  Unused.
2171  *
2172  * Returns @count on success, negative value otherwise.
2173  */
2174 static ssize_t tomoyo_write(struct file *file, const char __user *buf,
2175                             size_t count, loff_t *ppos)
2176 {
2177         return tomoyo_write_control(file, buf, count);
2178 }
2179
2180 /*
2181  * tomoyo_operations is a "struct file_operations" which is used for handling
2182  * /sys/kernel/security/tomoyo/ interface.
2183  *
2184  * Some files under /sys/kernel/security/tomoyo/ directory accept open(O_RDWR).
2185  * See tomoyo_io_buffer for internals.
2186  */
2187 static const struct file_operations tomoyo_operations = {
2188         .open    = tomoyo_open,
2189         .release = tomoyo_release,
2190         .read    = tomoyo_read,
2191         .write   = tomoyo_write,
2192 };
2193
2194 /**
2195  * tomoyo_create_entry - Create interface files under /sys/kernel/security/tomoyo/ directory.
2196  *
2197  * @name:   The name of the interface file.
2198  * @mode:   The permission of the interface file.
2199  * @parent: The parent directory.
2200  * @key:    Type of interface.
2201  *
2202  * Returns nothing.
2203  */
2204 static void __init tomoyo_create_entry(const char *name, const mode_t mode,
2205                                        struct dentry *parent, const u8 key)
2206 {
2207         securityfs_create_file(name, mode, parent, ((u8 *) NULL) + key,
2208                                &tomoyo_operations);
2209 }
2210
2211 /**
2212  * tomoyo_initerface_init - Initialize /sys/kernel/security/tomoyo/ interface.
2213  *
2214  * Returns 0.
2215  */
2216 static int __init tomoyo_initerface_init(void)
2217 {
2218         struct dentry *tomoyo_dir;
2219
2220         /* Don't create securityfs entries unless registered. */
2221         if (current_cred()->security != &tomoyo_kernel_domain)
2222                 return 0;
2223
2224         tomoyo_dir = securityfs_create_dir("tomoyo", NULL);
2225         tomoyo_create_entry("domain_policy",    0600, tomoyo_dir,
2226                             TOMOYO_DOMAINPOLICY);
2227         tomoyo_create_entry("exception_policy", 0600, tomoyo_dir,
2228                             TOMOYO_EXCEPTIONPOLICY);
2229         tomoyo_create_entry("self_domain",      0400, tomoyo_dir,
2230                             TOMOYO_SELFDOMAIN);
2231         tomoyo_create_entry(".domain_status",   0600, tomoyo_dir,
2232                             TOMOYO_DOMAIN_STATUS);
2233         tomoyo_create_entry(".process_status",  0600, tomoyo_dir,
2234                             TOMOYO_PROCESS_STATUS);
2235         tomoyo_create_entry("meminfo",          0600, tomoyo_dir,
2236                             TOMOYO_MEMINFO);
2237         tomoyo_create_entry("profile",          0600, tomoyo_dir,
2238                             TOMOYO_PROFILE);
2239         tomoyo_create_entry("manager",          0600, tomoyo_dir,
2240                             TOMOYO_MANAGER);
2241         tomoyo_create_entry("version",          0400, tomoyo_dir,
2242                             TOMOYO_VERSION);
2243         return 0;
2244 }
2245
2246 fs_initcall(tomoyo_initerface_init);